Gas-filled capillaries for plasma-based accelerators

NASA Astrophysics Data System (ADS)

Filippi, F.; Anania, M. P.; Brentegani, E.; Biagioni, A.; Cianchi, A.; Chiadroni, E.; Ferrario, M.; Pompili, R.; Romeo, S.; Zigler, A.

2017-07-01

Plasma Wakefield Accelerators are based on the excitation of large amplitude plasma waves excited by either a laser or a particle driver beam. The amplitude of the waves, as well as their spatial dimensions and the consequent accelerating gradient depend strongly on the background electron density along the path of the accelerated particles. The process needs stable and reliable plasma sources, whose density profile must be controlled and properly engineered to ensure the appropriate accelerating mechanism. Plasma confinement inside gas filled capillaries have been studied in the past since this technique allows to control the evolution of the plasma, ensuring a stable and repeatable plasma density distribution during the interaction with the drivers. Moreover, in a gas filled capillary plasma can be pre-ionized by a current discharge to avoid ionization losses. Different capillary geometries have been studied to allow the proper temporal and spatial evolution of the plasma along the acceleration length. Results of this analysis obtained by varying the length and the number of gas inlets will be presented.

Characterization and classification of lupus patients based on plasma thermograms

PubMed Central

Chaires, Jonathan B.; Mekmaysy, Chongkham S.; DeLeeuw, Lynn; Sivils, Kathy L.; Harley, John B.; Rovin, Brad H.; Kulasekera, K. B.; Jarjour, Wael N.

2017-01-01

Objective Plasma thermograms (thermal stability profiles of blood plasma) are being utilized as a new diagnostic approach for clinical assessment. In this study, we investigated the ability of plasma thermograms to classify systemic lupus erythematosus (SLE) patients versus non SLE controls using a sample of 300 SLE and 300 control subjects from the Lupus Family Registry and Repository. Additionally, we evaluated the heterogeneity of thermograms along age, sex, ethnicity, concurrent health conditions and SLE diagnostic criteria. Methods Thermograms were visualized graphically for important differences between covariates and summarized using various measures. A modified linear discriminant analysis was used to segregate SLE versus control subjects on the basis of the thermograms. Classification accuracy was measured based on multiple training/test splits of the data and compared to classification based on SLE serological markers. Results Median sensitivity, specificity, and overall accuracy based on classification using plasma thermograms was 86%, 83%, and 84% compared to 78%, 95%, and 86% based on a combination of five antibody tests. Combining thermogram and serology information together improved sensitivity from 78% to 86% and overall accuracy from 86% to 89% relative to serology alone. Predictive accuracy of thermograms for distinguishing SLE and osteoarthritis / rheumatoid arthritis patients was comparable. Both gender and anemia significantly interacted with disease status for plasma thermograms (p<0.001), with greater separation between SLE and control thermograms for females relative to males and for patients with anemia relative to patients without anemia. Conclusion Plasma thermograms constitute an additional biomarker which may help improve diagnosis of SLE patients, particularly when coupled with standard diagnostic testing. Differences in thermograms according to patient sex, ethnicity, clinical and environmental factors are important considerations for application of thermograms in a clinical setting. PMID:29149219

Advanced Plasma Shape Control to Enable High-Performance Divertor Operation on NSTX-U

NASA Astrophysics Data System (ADS)

Vail, Patrick; Kolemen, Egemen; Boyer, Mark; Welander, Anders

2017-10-01

This work presents the development of an advanced framework for control of the global plasma shape and its application to a variety of shape control challenges on NSTX-U. Operations in high-performance plasma scenarios will require highly-accurate and robust control of the plasma poloidal shape to accomplish such tasks as obtaining the strong-shaping required for the avoidance of MHD instabilities and mitigating heat flux through regulation of the divertor magnetic geometry. The new control system employs a high-fidelity model of the toroidal current dynamics in NSTX-U poloidal field coils and conducting structures as well as a first-principles driven calculation of the axisymmetric plasma response. The model-based nature of the control system enables real-time optimization of controller parameters in response to time-varying plasma conditions and control objectives. The new control scheme is shown to enable stable and on-demand plasma operations in complicated magnetic geometries such as the snowflake divertor. A recently-developed code that simulates the nonlinear evolution of the plasma equilibrium is used to demonstrate the capabilities of the designed shape controllers. Plans for future real-time implementations on NSTX-U and elsewhere are also presented. Supported by the US DOE under DE-AC02-09CH11466.

Plasma under control: Advanced solutions and perspectives for plasma flux management in material treatment and nanosynthesis

NASA Astrophysics Data System (ADS)

Baranov, O.; Bazaka, K.; Kersten, H.; Keidar, M.; Cvelbar, U.; Xu, S.; Levchenko, I.

2017-12-01

Given the vast number of strategies used to control the behavior of laboratory and industrially relevant plasmas for material processing and other state-of-the-art applications, a potential user may find themselves overwhelmed with the diversity of physical configurations used to generate and control plasmas. Apparently, a need for clearly defined, physics-based classification of the presently available spectrum of plasma technologies is pressing, and the critically summary of the individual advantages, unique benefits, and challenges against key application criteria is a vital prerequisite for the further progress. To facilitate selection of the technological solutions that provide the best match to the needs of the end user, this work systematically explores plasma setups, focusing on the most significant family of the processes—control of plasma fluxes—which determine the distribution and delivery of mass and energy to the surfaces of materials being processed and synthesized. A novel classification based on the incorporation of substrates into plasma-generating circuitry is also proposed and illustrated by its application to a wide variety of plasma reactors, where the effect of substrate incorporation on the plasma fluxes is emphasized. With the key process and material parameters, such as growth and modification rates, phase transitions, crystallinity, density of lattice defects, and others being linked to plasma and energy fluxes, this review offers direction to physicists, engineers, and materials scientists engaged in the design and development of instrumentation for plasma processing and diagnostics, where the selection of the correct tools is critical for the advancement of emerging and high-performance applications.

Real-tiem Adaptive Control Scheme for Superior Plasma Confinement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexander Trunov, Ph.D.

2001-06-01

During this Phase I project, IOS, in collaboration with our subcontractors at General Atomics, Inc., acquired and analyzed measurement data on various plasma equilibrium modes. We developed a Matlab-based toolbox consisting of linear and neural network approximators that are capable of learning and predicting, with accuracy, the behavior of plasma parameters. We also began development of the control algorithm capable of using the model of the plasma obtained by the neural network approximator.

Lithium-based surfaces controlling fusion plasma behavior at the plasma-material interfacea)

NASA Astrophysics Data System (ADS)

Allain, Jean Paul; Taylor, Chase N.

2012-05-01

The plasma-material interface and its impact on the performance of magnetically confined thermonuclear fusion plasmas are considered to be one of the key scientific gaps in the realization of nuclear fusion power. At this interface, high particle and heat flux from the fusion plasma can limit the material's lifetime and reliability and therefore hinder operation of the fusion device. Lithium-based surfaces are now being used in major magnetic confinement fusion devices and have observed profound effects on plasma performance including enhanced confinement, suppression and control of edge localized modes (ELM), lower hydrogen recycling and impurity suppression. The critical spatial scale length of deuterium and helium particle interactions in lithium ranges between 5-100 nm depending on the incident particle energies at the edge and magnetic configuration. Lithium-based surfaces also range from liquid state to solid lithium coatings on a variety of substrates (e.g., graphite, stainless steel, refractory metal W/Mo/etc., or porous metal structures). Temperature-dependent effects from lithium-based surfaces as plasma facing components (PFC) include magnetohydrodynamic (MHD) instability issues related to liquid lithium, surface impurity, and deuterium retention issues, and anomalous physical sputtering increase at temperatures above lithium's melting point. The paper discusses the viability of lithium-based surfaces in future burning-plasma environments such as those found in ITER and DEMO-like fusion reactor devices.

Enhanced reproducibility of L-mode plasma discharges via physics-model-based q-profile feedback control in DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuster, Eugenio J.; Wehner, William P.; Barton, Joseph E.

Recent experiments on DIII-D demonstrate the potential of physics-model-based q-profile control to improve reproducibility of plasma discharges. A combined feed forward + feedback control scheme is employed to optimize the current ramp-up phase by consistently achieving target q profiles (Target 1: q min = 1.3,q 95 = 4:4; Target 2: q min = 1.65,q 95 = 5.0; Target 3: q min = 2.1,q 95 = 6:2) at prescribed times during the plasma formation phase (Target 1: t = 1.5 s; Target 2: t = 1:3 s; Target 3: t = 1.0 s). At the core of the control scheme ismore » a nonlinear, first-principles-driven, physics-based, control-oriented model of the plasma dynamics valid for low confinement (L-mode) scenarios. To prevent undesired L-H transitions, a constraint on the maximum allowable total auxiliary power is imposed in addition to the maximum powers for the individual heating and current-drive sources. Experimental results are presented to demonstrate the effectiveness of the combined feed forward + feedback control scheme to consistently achieve the desired target profiles at the predefined times. Here, these results also show how the addition of feedback control significantly improves upon the feed forward only control solution by reducing the matching error and also how the feedback controller is able to reduce the matching error as the constraint on the maximum allowable total auxiliary power is relaxed while keeping the plasma in L-mode.« less

Enhanced reproducibility of L-mode plasma discharges via physics-model-based q-profile feedback control in DIII-D

DOE PAGES

Schuster, Eugenio J.; Wehner, William P.; Barton, Joseph E.; ...

2017-08-09

Recent experiments on DIII-D demonstrate the potential of physics-model-based q-profile control to improve reproducibility of plasma discharges. A combined feed forward + feedback control scheme is employed to optimize the current ramp-up phase by consistently achieving target q profiles (Target 1: q min = 1.3,q 95 = 4:4; Target 2: q min = 1.65,q 95 = 5.0; Target 3: q min = 2.1,q 95 = 6:2) at prescribed times during the plasma formation phase (Target 1: t = 1.5 s; Target 2: t = 1:3 s; Target 3: t = 1.0 s). At the core of the control scheme ismore » a nonlinear, first-principles-driven, physics-based, control-oriented model of the plasma dynamics valid for low confinement (L-mode) scenarios. To prevent undesired L-H transitions, a constraint on the maximum allowable total auxiliary power is imposed in addition to the maximum powers for the individual heating and current-drive sources. Experimental results are presented to demonstrate the effectiveness of the combined feed forward + feedback control scheme to consistently achieve the desired target profiles at the predefined times. Here, these results also show how the addition of feedback control significantly improves upon the feed forward only control solution by reducing the matching error and also how the feedback controller is able to reduce the matching error as the constraint on the maximum allowable total auxiliary power is relaxed while keeping the plasma in L-mode.« less

Numerical Simulations of Plasma Based Flow Control Applications

NASA Technical Reports Server (NTRS)

Suzen, Y. B.; Huang, P. G.; Jacob, J. D.; Ashpis, D. E.

2005-01-01

A mathematical model was developed to simulate flow control applications using plasma actuators. The effects of the plasma actuators on the external flow are incorporated into Navier Stokes computations as a body force vector. In order to compute this body force vector, the model solves two additional equations: one for the electric field due to the applied AC voltage at the electrodes and the other for the charge density representing the ionized air. The model is calibrated against an experiment having plasma-driven flow in a quiescent environment and is then applied to simulate a low pressure turbine flow with large flow separation. The effects of the plasma actuator on control of flow separation are demonstrated numerically.

Gas Fuelling System for SST-1Tokamak

NASA Astrophysics Data System (ADS)

Dhanani, Kalpesh; Raval, D. C.; Khan, Ziauddin; Semwal, Pratibha; George, Siju; Paravastu, Yuvakiran; Thankey, Prashant; Khan, M. S.; Pradhan, Subrata

2017-04-01

SST-1 Tokamak, the first Indian Steady-state Superconducting experimental device is at present under operation in the Institute for Plasma Research. For plasma break down & initiation, piezoelectric valve based gas feed system is implemented as a primary requirement due to its precise control, easy handling, low construction and maintenance cost and its flexibility in the selection of the working gas. Hydrogen gas feeding with piezoelectric valve is used in the SST-1 plasma experiments. The piezoelectric valves used in SST-1 are remotely driven by a PXI based platform and are calibrated before each SST-1 plasma operation with precise control. This paper will present the technical development and the results of the gas fuelling system of SST-1.

Association of Plasma Neurofilament Light With Neurodegeneration in Patients With Alzheimer Disease.

PubMed

Mattsson, Niklas; Andreasson, Ulf; Zetterberg, Henrik; Blennow, Kaj

2017-05-01

Existing cerebrospinal fluid (CSF) or imaging (tau positron emission tomography) biomarkers for Alzheimer disease (AD) are invasive or expensive. Biomarkers based on standard blood test results would be useful in research, drug development, and clinical practice. Plasma neurofilament light (NFL) has recently been proposed as a blood-based biomarker for neurodegeneration in dementias. To test whether plasma NFL concentrations are increased in AD and associated with cognitive decline, other AD biomarkers, and imaging evidence of neurodegeneration. In this prospective case-control study, an ultrasensitive assay was used to measure plasma NFL concentration in 193 cognitively healthy controls, 197 patients with mild cognitive impairment (MCI), and 180 patients with AD dementia from the Alzheimer's Disease Neuroimaging Initiative. The study dates were September 7, 2005, to February 13, 2012. The plasma NFL analysis was performed in September 2016. Associations were tested between plasma NFL and diagnosis, Aβ pathologic features, CSF biomarkers of neuronal injury, cognition, brain structure, and metabolism. Among 193 cognitively healthy controls, 197 patients with mild cognitive impairment, and 180 patients with AD with dementia, plasma NFL correlated with CSF NFL (Spearman ρ = 0.59, P < .001). Plasma NFL was increased in patients with MCI (mean, 42.8 ng/L) and patients with AD dementia (mean, 51.0 ng/L) compared with controls (mean, 34.7 ng/L) (P < .001) and had high diagnostic accuracy for patients with AD with dementia vs controls (area under the receiver operating characteristic curve, 0.87, which is comparable to established CSF biomarkers). Plasma NFL was particularly high in patients with MCI and patients with AD dementia with Aβ pathologic features. High plasma NFL correlated with poor cognition and AD-related atrophy (at baseline and longitudinally) and with brain hypometabolism (longitudinally). Plasma NFL is associated with AD diagnosis and with cognitive, biochemical, and imaging hallmarks of the disease. This finding implies a potential usefulness for plasma NFL as a noninvasive biomarker in AD.

Combined magnetic and kinetic control of advanced tokamak steady state scenarios based on semi-empirical modelling

NASA Astrophysics Data System (ADS)

Moreau, D.; Artaud, J. F.; Ferron, J. R.; Holcomb, C. T.; Humphreys, D. A.; Liu, F.; Luce, T. C.; Park, J. M.; Prater, R.; Turco, F.; Walker, M. L.

2015-06-01

This paper shows that semi-empirical data-driven models based on a two-time-scale approximation for the magnetic and kinetic control of advanced tokamak (AT) scenarios can be advantageously identified from simulated rather than real data, and used for control design. The method is applied to the combined control of the safety factor profile, q(x), and normalized pressure parameter, βN, using DIII-D parameters and actuators (on-axis co-current neutral beam injection (NBI) power, off-axis co-current NBI power, electron cyclotron current drive power, and ohmic coil). The approximate plasma response model was identified from simulated open-loop data obtained using a rapidly converging plasma transport code, METIS, which includes an MHD equilibrium and current diffusion solver, and combines plasma transport nonlinearity with 0D scaling laws and 1.5D ordinary differential equations. The paper discusses the results of closed-loop METIS simulations, using the near-optimal ARTAEMIS control algorithm (Moreau D et al 2013 Nucl. Fusion 53 063020) for steady state AT operation. With feedforward plus feedback control, the steady state target q-profile and βN are satisfactorily tracked with a time scale of about 10 s, despite large disturbances applied to the feedforward powers and plasma parameters. The robustness of the control algorithm with respect to disturbances of the H&CD actuators and of plasma parameters such as the H-factor, plasma density and effective charge, is also shown.

Optical control of hard X-ray polarization by electron injection in a laser wakefield accelerator

PubMed Central

Schnell, Michael; Sävert, Alexander; Uschmann, Ingo; Reuter, Maria; Nicolai, Maria; Kämpfer, Tino; Landgraf, Björn; Jäckel, Oliver; Jansen, Oliver; Pukhov, Alexander; Kaluza, Malte Christoph; Spielmann, Christian

2013-01-01

Laser-plasma particle accelerators could provide more compact sources of high-energy radiation than conventional accelerators. Moreover, because they deliver radiation in femtosecond pulses, they could improve the time resolution of X-ray absorption techniques. Here we show that we can measure and control the polarization of ultra-short, broad-band keV photon pulses emitted from a laser-plasma-based betatron source. The electron trajectories and hence the polarization of the emitted X-rays are experimentally controlled by the pulse-front tilt of the driving laser pulses. Particle-in-cell simulations show that an asymmetric plasma wave can be driven by a tilted pulse front and a non-symmetric intensity distribution of the focal spot. Both lead to a notable off-axis electron injection followed by collective electron–betatron oscillations. We expect that our method for an all-optical steering is not only useful for plasma-based X-ray sources but also has significance for future laser-based particle accelerators. PMID:24026068

Analysis of Electromagnetic Wave Propagation in a Magnetized Re-Entry Plasma Sheath Via the Kinetic Equation

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2009-01-01

Based on a theoretical model of the propagation of electromagnetic waves through a hypersonically induced plasma, it has been demonstrated that the classical radiofrequency communications blackout that is experienced during atmospheric reentry can be mitigated through the appropriate control of an external magnetic field of nominal magnitude. The model is based on the kinetic equation treatment of Vlasov and involves an analytical solution for the electric and magnetic fields within the plasma allowing for a description of the attendant transmission, reflection and absorption coefficients. The ability to transmit through the magnetized plasma is due to the magnetic windows that are created within the plasma via the well-known whistler modes of propagation. The case of 2 GHz transmission through a re-entry plasma is considered. The coefficients are found to be highly sensitive to the prevailing electron density and will thus require a dynamic control mechanism to vary the magnetic field as the plasma evolves through the re-entry phase.

Development of a Power Electronics Unit for the Space Station Plasma Contactor

NASA Technical Reports Server (NTRS)

Hamley, John A.; Hill, Gerald M.; Patterson, Michael J.; Saggio, Joseph, Jr.; Terdan, Fred; Mansell, Justin D.

1994-01-01

A hollow cathode plasma contactor has been baselined as a charge control device for the Space Station (SS) to prevent deleterious interactions of coated structural components with the ambient plasma. NASA LeRC Work Package 4 initiated the development of a plasma contactor system comprised of a Power Electronics Unit (PEU), an Expellant Management Unit (EMU), a command and data interface, and a Plasma Contactor Unit (PCU). A breadboard PEU was designed and fabricated. The breadboard PEU contains a cathode heater and discharge power supply, which were required to operate the PCU, a control and auxiliary power converter, an EMU interface, a command and telemetry interface, and a controller. The cathode heater and discharge supplies utilized a push-pull topology with a switching frequency of 20 kHz and pulse-width-modulated (PWM) control. A pulse ignition circuit derived from that used in arcjet power processors was incorporated in the discharge supply for discharge ignition. An 8088 based microcontroller was utilized in the breadboard model to provide a flexible platform for controller development with a simple command/data interface incorporating a direct connection to SS Mulitplexer/Demultiplexer (MDM) analog and digital I/O cards. Incorporating this in the flight model would eliminate the hardware and software overhead associated with a 1553 serial interface. The PEU autonomously operated the plasma contactor based on command inputs and was successfully integrated with a prototype plasma contactor unit demonstrating reliable ignition of the discharge and steady-state operation.

The COMPASS Tokamak Plasma Control Software Performance

NASA Astrophysics Data System (ADS)

Valcarcel, Daniel F.; Neto, André; Carvalho, Ivo S.; Carvalho, Bernardo B.; Fernandes, Horácio; Sousa, Jorge; Janky, Filip; Havlicek, Josef; Beno, Radek; Horacek, Jan; Hron, Martin; Panek, Radomir

2011-08-01

The COMPASS tokamak has began operation at the IPP Prague in December 2008. A new control system has been built using an ATCA-based real-time system developed at IST Lisbon. The control software is implemented on top of the MARTe real-time framework attaining control cycles as short as 50 μs, with a jitter of less than 1 μs. The controlled parameters, important for the plasma performance, are the plasma current, position of the plasma current center, boundary shape and horizontal and vertical velocities. These are divided in two control cycles: slow at 500 μs and fast at 50 μs. The project has two phases. First, the software implements a digital controller, similar to the analog one used during the COMPASS-D operation in Culham. In the slow cycle, the plasma current and position are measured and controlled with PID and feedforward controllers, respectively, the shaping magnetic field is preprogrammed. The vertical instability and horizontal equilibrium are controlled with the faster 50-μs cycle PID controllers. The second phase will implement a plasma-shape reconstruction algorithm and controller, aiming at optimized plasma performance. The system was designed to be as modular as possible by breaking the functional requirements of the control system into several independent and specialized modules. This splitting enabled tuning the execution of each system part and to use the modules in a variety of applications with different time constraints. This paper presents the design and overall performance of the COMPASS control software.

Free circulating nucleic acids in plasma and serum as a novel approach to the use of internal controls in real time PCR based detection.

PubMed

Karataylı, Ersin; Altunoğlu, Yasemin Çelik; Karataylı, Senem Ceren; Yurdaydın, Cihan; Bozdayı, A Mithat

2014-10-01

Internal controls (ICs), are the main components of any real-time PCR based amplification methods, which are co-purified and co-amplified with the actual target. The existence of free circulating nucleic acids in plasma and serum (CNAPS) has been known for many years. The aim of this study was to verify whether CNAPS can be used as ICs in real-time PCR based detection and quantification of DNA or RNA targets in plasma and serum samples. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a housekeeping gene, was chosen at random as CNAPS to serve as an intrinsic internal control in two different real-time PCR based quantification models in plasma and serum. Viral loads of hepatitis B virus (HBV) DNA and hepatitis delta virus (HDV) RNA were quantified as actual targets in parallel to GAPDH as IC in a total of 519 serum or plasma samples including 21 healthy controls, 202 positive chronic hepatitis delta patients, 37 chronic hepatitis C patients, 168 chronic hepatitis B patients, 52 patients with hepatocellular carcinoma, and 39 patients with non-alcoholic steatohepatitis/non-alcoholic fatty liver disease. GAPDH levels did not show significant variance in different patient groups and yielded positive signals in all 519 patients with persistent cycle threshold (CT) values 27.85±1.57 (mean±standard deviation (SD)). Reproducibility of the GAPDH amplification in HDV RNA and HBV DNA quantifications was shown with a SD value of CT ranging from 0.42 to 2.14 (mean SD; 1.18) and 0.24 to 1.75 (mean SD; 1.03), respectively. In conclusion, the freely circulating nucleic acids can clearly be used as internal controls for real-time PCR based detection and quantification of any RNA and mainly DNA targets (pathogens) in serum or plasma and this simply excludes the compulsory external addition of any IC molecules into the reaction. Copyright © 2014 Elsevier B.V. All rights reserved.

Computer-Controlled System for Plasma Ion Energy Auto-Analyzer

NASA Astrophysics Data System (ADS)

Wu, Xian-qiu; Chen, Jun-fang; Jiang, Zhen-mei; Zhong, Qing-hua; Xiong, Yu-ying; Wu, Kai-hua

2003-02-01

A computer-controlled system for plasma ion energy auto-analyzer was technically studied for rapid and online measurement of plasma ion energy distribution. The system intelligently controls all the equipments via a RS-232 port, a printer port and a home-built circuit. The software designed by Lab VIEW G language automatically fulfils all of the tasks such as system initializing, adjustment of scanning-voltage, measurement of weak-current, data processing, graphic export, etc. By using the system, a few minutes are taken to acquire the whole ion energy distribution, which rapidly provides important parameters of plasma process techniques based on semiconductor devices and microelectronics.

Design of an Integrated Plasma Control System and Extension of XSCTools to Ignitor

NASA Astrophysics Data System (ADS)

Albanese, R.; Ambrosino, G.; Artaserse, G.; Pironti, A.; Rubinacci, G.; Villone, F.; Ramogida, G.

2010-11-01

The performance of the integrated system for vertical stability, shape and plasma current control for the Ignitor machine has been assessed by means of the CREATELlinearized model of plasma responseootnotetextR. Albanese, F. Villone, Nucl. Fusion 38, 723 (1998) against a set of disturbances for the reference 11 MA limiter configuration and the 9 MA Double Null configuration. A new design, based on the methodology of the eXtreme Shape Controller (XSC) at JET, has been tested : by using all the shape control circuits with the exception of those used to control the vertical stability is possible to control up to four independent linear combinations of the 36 plasma-wall gaps. The results point out a substantial improvement in shape recovery, especially in the presence of a disturbance in li. The new shape controller can also automatically generate, via feedback control, new plasma shapes in the proximity of a given equilibrium configuration. The XSC ToolsootnotetextG. Ambrosino, R. Albanese et al., Fus. Eng.& Des. 74, 521 (2005) have been adapted and extended to develop linearized Ignitor models including 2D eddy currents and to solve inverse linearized plasma equilibria.

Suppression of tritium retention in remote areas of ITER by nonperturbative reactive gas injection.

PubMed

Tabarés, F L; Ferreira, J A; Ramos, A; van Rooij, G; Westerhout, J; Al, R; Rapp, J; Drenik, A; Mozetic, M

2010-10-22

A technique based on reactive gas injection in the afterglow region of the divertor plasma is proposed for the suppression of tritium-carbon codeposits in remote areas of ITER when operated with carbon-based divertor targets. Experiments in a divertor simulator plasma device indicate that a 4  nm/min deposition can be suppressed by addition of 1  Pa·m³ s⁻¹ ammonia flow at 10 cm from the plasma. These results bolster the concept of nonperturbative scavenger injection for tritium inventory control in carbon-based fusion plasma devices, thus paving the way for ITER operation in the active phase under a carbon-dominated, plasma facing component background.

Hybrid Method for Power Control Simulation of a Single Fluid Plasma Thruster

NASA Astrophysics Data System (ADS)

Jaisankar, S.; Sheshadri, T. S.

2018-05-01

Propulsive plasma flow through a cylindrical-conical diverging thruster is simulated by a power controlled hybrid method to obtain the basic flow, thermodynamic and electromagnetic variables. Simulation is based on a single fluid model with electromagnetics being described by the equations of potential Poisson, Maxwell and the Ohm's law while the compressible fluid dynamics by the Navier Stokes in cylindrical form. The proposed method solved the electromagnetics and fluid dynamics separately, both to segregate the two prominent scales for an efficient computation and for the delivery of voltage controlled rated power. The magnetic transport is solved for steady state while fluid dynamics is allowed to evolve in time along with an electromagnetic source using schemes based on generalized finite difference discretization. The multistep methodology with power control is employed for simulating fully ionized propulsive flow of argon plasma through the thruster. Numerical solution shows convergence of every part of the solver including grid stability causing the multistep hybrid method to converge for a rated power delivery. Simulation results are reasonably in agreement with the reported physics of plasma flow in the thruster thus indicating the potential utility of this hybrid computational framework, especially when single fluid approximation of plasma is relevant.

Effect of ECRH and resonant magnetic fields on formation of magnetic islands in the T-10 tokamak plasma

NASA Astrophysics Data System (ADS)

Shestakov, E. A.; Savrukhin, P. V.

2017-10-01

Experiments in the T-10 tokamak demonstrated possibility of controlling the plasma current during disruption instability using the electron cyclotron resonance heating (ECRH) and the controlled operation of the ohmic current-holding system. Quasistable plasma discharge with repeating sawtooth oscillations can be restored after energy quench using auxiliary ECRH power when PEC / POH > 2-5. The external magnetic field generation system consisted of eight saddle coils that were arranged symmetrically relative to the equatorial plane of the torus outside of the vacuum vessel of the T-10 tokamak to study the possible resonant magnetic field effects on the rotation frequency of magnetic islands. The saddle coils power supply system is based on four thyristor converters with a total power of 300 kW. The power supply control system is based on Siemens S7 controllers. As shown by preliminary experiments, the interaction efficiency of external magnetic fields with plasma depends on the plasma magnetic configuration. Optimal conditions for slowing the rotation of magnetic islands were determined. Additionally, the direction of the error magnetic field in the T-10 tokamak was determined, and the threshold value of the external magnetic field was determined.

Application of nonlocal plasma technology for controlling plasma conductivity

NASA Astrophysics Data System (ADS)

Yuan, Chengxun; Demidov, V. I.; Kudryavtsev, A. A.; Kurlyandskaya, I. P.; Rudakova, T. V.; Zhou, Z. X.

2017-10-01

A promising approach for better control of the plasma parameters involves the exploitation of peculiarities of plasmas with a nonlocal electron energy distribution. Nonlocal plasma technology (NLP-technology) is based on the effect of energetic electrons in the plasma volume. In this work, an experimental study of influence of the chemo-ionization processes on non-stationary plasma conductivity has been conducted. Due to energetic, supra-thermal electrons, which appear in the chemo-ionization reactions, the highly non-equilibrium and time dependent nonlocal electron energy distribution function is formed. In such a plasma thermal electrons always have positive conductivity (mobility), while supra-thermal, energetic electrons may have negative conductivity in heavy (argon, krypton and xenon) noble gases dependently on conditions. Experiments demonstrate that this effect may lead to the non-monotonic temporal behavior of plasma conductivity and may potentially create the negative electron mobility.

Peptidomic analysis of endogenous plasma peptides from patients with pancreatic neuroendocrine tumours.

PubMed

Kay, Richard G; Challis, Benjamin G; Casey, Ruth T; Roberts, Geoffrey P; Meek, Claire L; Reimann, Frank; Gribble, Fiona M

2018-06-01

Diagnosis of pancreatic neuroendocrine tumours requires the study of patient plasma with multiple immunoassays, using multiple aliquots of plasma. The application of mass spectrometry based techniques could reduce the cost and amount of plasma required for diagnosis. Plasma samples from two patients with pancreatic neuroendocrine tumours were extracted using an established acetonitrile based plasma peptide enrichment strategy. The circulating peptidome was characterised using nano and high flow rate LC/MS analyses. To assess the diagnostic potential of the analytical approach, a large sample batch (68 plasmas) from control subjects, and aliquots from subjects harbouring two different types of pancreatic neuroendocrine tumour (insulinoma and glucagonoma) were analysed using a 10-minute LC/MS peptide screen. The untargeted plasma peptidomics approach identified peptides derived from the glucagon prohormone, chromogranin A, chromogranin B and other peptide hormones and proteins related to control of peptide secretion. The glucagon prohormone derived peptides that were detected were compared against putative peptides that were identified using multiple antibody pairs against glucagon peptides. Comparison of the plasma samples for relative levels of selected peptides showed clear separation between the glucagonoma and the insulinoma and control samples. The combination of the organic solvent extraction methodology with high flow rate analysis could potentially be used to aid diagnosis and monitor treatment of patients with functioning pancreatic neuroendocrine tumours. However, significant validation will be required before this approach can be clinically applied. This article is protected by copyright. All rights reserved.

Bioavailability of ambroxol sustained release preparations. Part II: Single and multiple oral dose studies in man.

PubMed

Janssen, T J; Guelen, P J; Vree, T B; Botterblom, M H; Valducci, R

1988-01-01

The bioavailability of a new ambroxol sustained release preparation (75 mg) based on a dialyzing membrane for controlled release was studied in healthy volunteers after single and multiple oral dose in comparison with a standard sustained release formulation in a cross-over study under carefully controlled conditions. Plasma concentrations of ambroxol were measured by means of a HPLC method. Based on AUC data both preparations are found to be bioequivalent, but show different plasma concentration profiles. The test preparation showed a more pronounced sustained release profile than the reference preparation (single dose) resulting in significantly higher steady state plasma levels.

Real time closed loop control of an Ar and Ar/O2 plasma in an ICP

NASA Astrophysics Data System (ADS)

Faulkner, R.; Soberón, F.; McCarter, A.; Gahan, D.; Karkari, S.; Milosavljevic, V.; Hayden, C.; Islyaikin, A.; Law, V. J.; Hopkins, M. B.; Keville, B.; Iordanov, P.; Doherty, S.; Ringwood, J. V.

2006-10-01

Real time closed loop control for plasma assisted semiconductor manufacturing has been the subject of academic research for over a decade. However, due to process complexity and the lack of suitable real time metrology, progress has been elusive and genuine real time, multi-input, multi-output (MIMO) control of a plasma assisted process has yet to be successfully implemented in an industrial setting. A Splasma parameter control strategy T is required to be adopted whereby process recipes which are defined in terms of plasma properties such as critical species densities as opposed to input variables such as rf power and gas flow rates may be transferable between different chamber types. While PIC simulations and multidimensional fluid models have contributed considerably to the basic understanding of plasmas and the design of process equipment, such models require a large amount of processing time and are hence unsuitable for testing control algorithms. In contrast, linear dynamical empirical models, obtained through system identification techniques are ideal in some respects for control design since their computational requirements are comparatively small and their structure facilitates the application of classical control design techniques. However, such models provide little process insight and are specific to an operating point of a particular machine. An ideal first principles-based, control-oriented model would exhibit the simplicity and computational requirements of an empirical model and, in addition, despite sacrificing first principles detail, capture enough of the essential physics and chemistry of the process in order to provide reasonably accurate qualitative predictions. This paper will discuss the development of such a first-principles based, control-oriented model of a laboratory inductively coupled plasma chamber. The model consists of a global model of the chemical kinetics coupled to an analytical model of power deposition. Dynamics of actuators including mass flow controllers and exhaust throttle are included and sensor characteristics are also modelled. The application of this control-oriented model to achieve multivariable closed loop control of specific species e.g. atomic Oxygen and ion density using the actuators rf power, Oxygen and Argon flow rates, and pressure/exhaust flow rate in an Ar/O2 ICP plasma will be presented.

Aberrant glycosylation of plasma proteins in severe preeclampsia promotes monocyte adhesion.

PubMed

Flood-Nichols, Shannon K; Kazanjian, Avedis A; Tinnemore, Deborah; Gafken, Philip R; Ogata, Yuko; Napolitano, Peter G; Stallings, Jonathan D; Ippolito, Danielle L

2014-02-01

Glycosylation of plasma proteins increases during pregnancy. Our objectives were to investigate an anti-inflammatory role of these proteins in normal pregnancies and determine whether aberrant protein glycosylation promotes monocyte adhesion in preeclampsia. Plasma was prospectively collected from nonpregnant controls and nulliparous patients in all 3 trimesters. Patients were divided into cohorts based on the applicable postpartum diagnosis. U937 monocytes were preconditioned with enzymatically deglycosylated plasma, and monocyte adhesion to endothelial cell monolayers was quantified by spectrophotometry. Plasma from nonpregnant controls, first trimester normotensives, and first trimester patients with mild preeclampsia inhibited monocyte-endothelial cell adhesion (P < .05), but plasma from first trimester patients with severe preeclampsia and second and third trimester normotensives did not. Deglycosylating plasma proteins significantly increased adhesion in all the cohorts. These results support a role of plasma glycoprotein interaction in monocyte-endothelial cell adhesion and could suggest a novel therapeutic target for severe preeclampsia.

Identification and control of plasma vertical position using neural network in Damavand tokamak.

PubMed

Rasouli, H; Rasouli, C; Koohi, A

2013-02-01

In this work, a nonlinear model is introduced to determine the vertical position of the plasma column in Damavand tokamak. Using this model as a simulator, a nonlinear neural network controller has been designed. In the first stage, the electronic drive and sensory circuits of Damavand tokamak are modified. These circuits can control the vertical position of the plasma column inside the vacuum vessel. Since the vertical position of plasma is an unstable parameter, a direct closed loop system identification algorithm is performed. In the second stage, a nonlinear model is identified for plasma vertical position, based on the multilayer perceptron (MLP) neural network (NN) structure. Estimation of simulator parameters has been performed by back-propagation error algorithm using Levenberg-Marquardt gradient descent optimization technique. The model is verified through simulation of the whole closed loop system using both simulator and actual plant in similar conditions. As the final stage, a MLP neural network controller is designed for simulator model. In the last step, online training is performed to tune the controller parameters. Simulation results justify using of the NN controller for the actual plant.

Vertical Position and Current Profile Measurements by Faraday-effect Polarimetry On EAST tokamak

NASA Astrophysics Data System (ADS)

Ding, Weixing; Liu, H. Q.; Jie, Y. X.; Brower, D. L.; Qian, J. P.; Zou, Z. Y.; Lian, H.; Wang, S. X.; Luo, Z. P.; Xiao, B. J.; Ucla Team; Asipp Team

2017-10-01

A primary goal for ITER and prospective fusion power reactors is to achieve controlled long-pulse/steady-state burning plasmas. For elongated divertor plasmas, both the vertical position and current profile have to be precisely controlled to optimize performance and prevent disruptions. An eleven-channel laser-based POlarimeter-INTerferometer (POINT) system has been developed for measuring the internal magnetic field in the EAST tokamak and can be used to obtain the plasma current profile and vertical position. Current profiles are determined from equilibrium reconstruction including internal magnetic field measurements as internal constraints. Horizontally-viewing chords at/near the mid-plane allow us to determine plasma vertical position non-inductively with subcentimeter spatial resolution and time response up to 1 s. The polarimeter-based position measurement, which does not require equilibrium reconstruction, is benchmarked against conventional flux loop measurements and can be exploited for feedback control. Work supported by US DOE through Grants No. DE-FG02-01ER54615 and No. DC-SC0010469.

Tuning model drug release and soft-tissue bioadhesion of polyester films by plasma post-treatment.

PubMed

Mogal, Vishal T; Yin, Chaw Su; O'Rorke, Richard; Boujday, Souhir; Méthivier, Christophe; Venkatraman, Subbu S; Steele, Terry W J

2014-04-23

Plasma treatments are investigated as a post-production method of tuning drug release and bioadhesion of poly(lactic-co-glycolic acid) (PLGA) thin films. PLGA films were treated under varying conditions by controlling gas flow rate, composition, treatment time, and radio frequency (RF) power. In vitro release of the drug-like molecule fluorescein diacetate (FDAc) from plasma-treated PLGA was tunable by controlling RF power; an increase of 65% cumulative release is reported compared to controls. Bioadhesion was sensitive to RF power and treatment time, assessed using ex vivo shear-stress tests with wetted swine aorta. We report a maximum bioadhesion ∼6-fold that of controls and 5-fold that of DOPA-based mussel adhesives tested to swine skin.1 The novelty of this post-treatment is the activation of a hydrophobic polyester film for bioadhesion, which can be quenched, while simultaneously tuning drug-release kinetics. This exemplifies the promise of plasma post-treatment for in-clinic bioadhesive activation, along with technological advancements, i.e., atmospheric plasma and hand-held "plasma pencils".

MiOXSYS: a novel method of measuring oxidation reduction potential in semen and seminal plasma.

PubMed

Agarwal, Ashok; Sharma, Rakesh; Roychoudhury, Shubhadeep; Du Plessis, Stefan; Sabanegh, Edmund

2016-09-01

To measure oxidative reduction potential (ORP) in semen and seminal plasma and to establish their reference levels. ORP levels were measured in semen and seminal plasma. Tertiary hospital. Twenty-six controls and 33 infertile men. None. Static ORP (sORP) and capacitance ORP (cORP) were measured in semen and seminal plasma at time 0 and 120 minutes. Correlation of ORP was assessed between [1] semen and seminal plasma and [2] time 0 and 120 minutes. The association with sperm parameters was studied in (a) controls and (b) infertile patients, and a receiver operating characteristic curve was generated to establish the sORP cutoff. Semen sORP and cORP levels were associated with seminal plasma levels at time 0 and time 120 minutes. In controls and infertile patients, an inverse relationship of sORP levels was established with concentration and total sperm count in semen as well as seminal plasma at time 0 and 120 minutes. Classification of subjects based on sperm motility showed that subjects with abnormal motility present with poor concentration, total count, morphology, and elevated levels of semen and seminal plasma sORP at time 120 minutes. The sORP cutoff of 1.48 in semen and 2.09 in seminal plasma based on motility was able to distinguish subjects with normal semen quality from those with abnormal semen quality. The MiOXSYS System can reliably measure ORP levels in semen and seminal plasma. ORP levels are not affected by semen age, making this new technology easy to employ in a clinical setting. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Leading edge vortex control on a delta wing with dielectric barrier discharge plasma actuators

NASA Astrophysics Data System (ADS)

Shen, Lu; Wen, Chih-yung

2017-06-01

This paper presents an experimental investigation of the application of dielectric barrier discharge (DBD) plasma actuators on a slender delta wing to control the leading edge vortices (LEVs). The experiments are conducted in a wind tunnel with a Reynolds number of 50 000 based on the chord length. The smoke flow visualization reveals that the DBD plasma actuators at the leading edges significantly modify the vortical flow structure over the delta wing. It is noted that symmetric control at both semi-spans and asymmetric control at a single semi-span leads to opposite effects on the local LEVs. Particle image velocimetry (PIV) indicates that the shear layer is deformed by the actuators. Therefore, both the strength and the shape of the LEV cores are deeply affected. The six-component force measurement shows that the DBD plasma actuators have a limited effect on lift and drag while inducing relatively large moments. This suggests that the DBD plasma actuator is a promising technique for delta wing maneuvering.

Understanding plasma biofilm interactions for controlling infection and virulence

NASA Astrophysics Data System (ADS)

Flynn, Padrig B.; Gilmore, Brendan F.

2018-07-01

Bacterial biofilms are surface adhered communities of bacteria encased within a protective extracellular polymeric matrix. These heterogeneous microbial communities are characterized by elevated tolerance to antimicrobial agents, host immune clearance mechanisms and physical disinfection approaches. Atmospheric pressure non-thermal plasmas have proven to be highly effective in the eradication of bacteria and fungi in both planktonic and biofilm modes of growth at low temperatures, making it a promising approach for surface decontamination of both biotic and abiotic surfaces alike. In addition, non-thermal plasmas as a putative non-antibiotic approach to controlling infectious microorganisms, holds significant promise as an antibiotic alternative infection control strategy, with demonstrated efficacy against antibiotic resistant microorganisms. This topical review introduces the reader to key concepts in biofilm tolerance mechanisms relevant to treatment and control of these surface adhered bacterial communities with cold plasmas. In addition, the ability of plasma-derived active species to interact with both biofilm extracellular matrix components and bacterial cellular targets will be discussed in order to elucidate the mechanisms of antimicrobial and antibiofilm action. By understanding these fundamental interactions, plasma sources may be precisely tailored for antimicrobial applications, specifically for biofilm control where bacterial and fungal physiology (and sensitivity to physical and chemical decontamination) is markedly different from that of their planktonic, or free swimming, counterparts. Recently, novel roles for reactive oxygen and nitrogen species in the activity of conventional antibiotics have been proposed. This extends the possibility that plasmas may enhance the activity of conventional antibiotics and biocides in controlling these highly tolerant microbial populations. Lessons from classical biofilm microbiology can be usefully translated and applied to the design of plasma-based approaches aimed at biofilm control, while potential for tolerance and persistence to plasma in bacterial communities will be reviewed.

Real-time plasma control based on the ISTTOK tomography diagnostica)

NASA Astrophysics Data System (ADS)

Carvalho, P. J.; Carvalho, B. B.; Neto, A.; Coelho, R.; Fernandes, H.; Sousa, J.; Varandas, C.; Chávez-Alarcón, E.; Herrera-Velázquez, J. J. E.

2008-10-01

The presently available processing power in generic processing units (GPUs) combined with state-of-the-art programmable logic devices benefits the implementation of complex, real-time driven, data processing algorithms for plasma diagnostics. A tomographic reconstruction diagnostic has been developed for the ISTTOK tokamak, based on three linear pinhole cameras each with ten lines of sight. The plasma emissivity in a poloidal cross section is computed locally on a submillisecond time scale, using a Fourier-Bessel algorithm, allowing the use of the output signals for active plasma position control. The data acquisition and reconstruction (DAR) system is based on ATCA technology and consists of one acquisition board with integrated field programmable gate array (FPGA) capabilities and a dual-core Pentium module running real-time application interface (RTAI) Linux. In this paper, the DAR real-time firmware/software implementation is presented, based on (i) front-end digital processing in the FPGA; (ii) a device driver specially developed for the board which enables streaming data acquisition to the host GPU; and (iii) a fast reconstruction algorithm running in Linux RTAI. This system behaves as a module of the central ISTTOK control and data acquisition system (FIRESIGNAL). Preliminary results of the above experimental setup are presented and a performance benchmarking against the magnetic coil diagnostic is shown.

Combined magnetic and kinetic control of advanced tokamak steady state scenarios based on semi-empirical modelling

DOE PAGES

Moreau, Didier; Artaud, J. F.; Ferron, John R.; ...

2015-05-01

This paper shows that semi-empirical data-driven models based on a twotime- scale approximation for the magnetic and kinetic control of advanced tokamak (AT) scenarios can be advantageously identified from simulated rather than real data, and used for control design. The method is applied to the combined control of the safety factor profile, q(x), and normalized pressure parameter, β N, using DIII-D parameters and actuators (on-axis co-current neutral beam injection (NBI) power, off axis co-current NBI power, electron cyclotron current drive power, and ohmic coil). The approximate plasma response model was identified from simulated data obtained using a rapidly converging plasmamore » transport code, METIS, which includes an MHD equilibrium and current diffusion solver, and combines plasma transport nonlinearity with 0-D scaling laws and 1.5-D ordinary differential equations. A number of open loop simulations were performed, in which the heating and current drive (H&CD) sources were randomly modulated around the typical values of a reference AT discharge on DIIID. Using these simulated data, a two-time-scale state space model was obtained for the coupled evolution of the poloidal flux profile and βN parameter, and a controller was synthesized based on the near-optimal ARTAEMIS algorithm [D. Moreau et al., Nucl. Fusion 53 (2013) 063020]. The paper discusses the results of closed-loop nonlinear simulations, using this controller for steady state AT operation. With feedforward plus feedback control, the steady state target q-profile and β N are satisfactorily tracked with a time scale of about ten seconds, despite large disturbances applied to the feedforward powers and plasma parameters. The effectiveness of the control algorithm is thus demonstrated for long pulse and steady state high-β N AT discharges. Its robustness with respect to disturbances of the H&CD actuators and of plasma parameters such as the H-factor, plasma density and effective charge, is also shown.« less

Coherent control of plasma dynamics by feedback-optimized wavefront manipulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Z.-H.; Hou, B.; Gao, G.

2015-05-15

Plasmas generated by an intense laser pulse can support coherent structures such as large amplitude wakefield that can affect the outcome of an experiment. We investigate the coherent control of plasma dynamics by feedback-optimized wavefront manipulation using a deformable mirror. The experimental outcome is directly used as feedback in an evolutionary algorithm for optimization of the phase front of the driving laser pulse. In this paper, we applied this method to two different experiments: (i) acceleration of electrons in laser driven plasma waves and (ii) self-compression of optical pulses induced by ionization nonlinearity. The manipulation of the laser wavefront leadsmore » to orders of magnitude improvement to electron beam properties such as the peak charge, beam divergence, and transverse emittance. The demonstration of coherent control for plasmas opens new possibilities for future laser-based accelerators and their applications.« less

High speed FPGA-based Phasemeter for the far-infrared laser interferometers on EAST

NASA Astrophysics Data System (ADS)

Yao, Y.; Liu, H.; Zou, Z.; Li, W.; Lian, H.; Jie, Y.

2017-12-01

The far-infrared laser-based HCN interferometer and POlarimeter/INTerferometer\\break (POINT) system are important diagnostics for plasma density measurement on EAST tokamak. Both HCN and POINT provide high spatial and temporal resolution of electron density measurement and used for plasma density feedback control. The density is calculated by measuring the real-time phase difference between the reference beams and the probe beams. For long-pulse operations on EAST, the calculation of density has to meet the requirements of Real-Time and high precision. In this paper, a Phasemeter for far-infrared laser-based interferometers will be introduced. The FPGA-based Phasemeter leverages fast ADCs to obtain the three-frequency signals from VDI planar-diode Mixers, and realizes digital filters and an FFT algorithm in FPGA to provide real-time, high precision electron density output. Implementation of the Phasemeter will be helpful for the future plasma real-time feedback control in long-pulse discharge.

Simulation Tool for Dielectric Barrier Discharge Plasma Actuators

NASA Technical Reports Server (NTRS)

Likhanskii, Alexander

2014-01-01

Traditional approaches for active flow separation control using dielectric barrier discharge (DBD) plasma actuators are limited to relatively low speed flows and atmospheric conditions. This results in low feasibility of the DBDs for aerospace applications. For active flow control at turbine blades, fixed wings, and rotary wings and on hypersonic vehicles, DBD plasma actuators must perform at a wide range of conditions, including rarified flows and combustion mixtures. An efficient, comprehensive, physically based DBD simulation tool can optimize DBD plasma actuators for different operation conditions. Researchers are developing a DBD plasma actuator simulation tool for a wide range of ambient gas pressures. The tool will treat DBD using either kinetic, fluid, or hybrid models, depending on the DBD operational condition.

Coherent control of plasma dynamics

NASA Astrophysics Data System (ADS)

He, Zhaohan

2014-10-01

The concept of coherent control - precise measurement or determination of a process through control of the phase of an applied oscillating field - has been applied to numerous systems with great success. Here, we demonstrate the use of coherent control on plasma dynamics in a laser wakefield electron acceleration experiment. A tightly focused femtosecond laser pulse (10 mJ, 35 fs) was used to generate electron beams by plasma wakefield acceleration in the density down ramp. The technique is based on optimization of the electron beam using a deformable mirror adaptive optical system with an iterative evolutionary genetic algorithm. The image of the electrons on a scintillator screen was processed and used in a fitness function as direct feedback for the optimization algorithm. This coherent manipulation of the laser wavefront leads to orders of magnitude improvement to the electron beam properties such as the peak charge and beam divergence. The laser beam optimized to generate the best electron beam was not the one with the ``best'' focal spot. When a particular wavefront of laser light interacts with plasma, it can affect the plasma wave structures and trapping conditions of the electrons in a complex way. For example, Raman forward scattering, envelope self-modulation, relativistic self-focusing, and relativistic self-phase modulation and many other nonlinear interactions modify both the pulse envelope and phase as the pulse propagates, in a way that cannot be easily predicted and that subsequently dictates the formation of plasma waves. The optimal wavefront could be successfully determined via the heuristic search under laser-plasma conditions that were not known a priori. Control and shaping of the electron energy distribution was found to be less effective, but was still possible. Particle-in-cell simulations were performed to show that the mode structure of the laser beam can affect the plasma wave structure and trapping conditions of electrons, which subsequently produces electron beams with a different divergence. The proof-of-principle demonstration of coherent control for plasmas opens new possibilities for future laser-based accelerators and their applications. This study should also enable a significantly improved understanding of the complex dynamics of laser plasma interactions. This work was supported by DARPA under Contract No. N66001-11-1-4208, the NSF under Contract No. 0935197 and MCubed at the University of Michigan.

Simultaneous feedback control of plasma rotation and stored energy on NSTX-U using neoclassical toroidal viscosity and neutral beam injection

NASA Astrophysics Data System (ADS)

Goumiri, I. R.; Rowley, C. W.; Sabbagh, S. A.; Gates, D. A.; Boyer, M. D.; Gerhardt, S. P.; Kolemen, E.; Menard, J. E.

2017-05-01

A model-based feedback system is presented enabling the simultaneous control of the stored energy through βn and the toroidal rotation profile of the plasma in National Spherical Torus eXperiment Upgrade device. Actuation is obtained using the momentum from six injected neutral beams and the neoclassical toroidal viscosity generated by applying three-dimensional magnetic fields. Based on a model of the momentum diffusion and torque balance, a feedback controller is designed and tested in closed-loop simulations using TRANSP, a time dependent transport analysis code, in predictive mode. Promising results for the ongoing experimental implementation of controllers are obtained.

Simultaneous feedback control of plasma rotation and stored energy on NSTX-U using neoclassical toroidal viscosity and neutral beam injection

PubMed Central

Goumiri, I. R.; Sabbagh, S. A.; Boyer, M. D.; Gerhardt, S. P.; Kolemen, E.; Menard, J. E.

2017-01-01

A model-based feedback system is presented enabling the simultaneous control of the stored energy through βn and the toroidal rotation profile of the plasma in National Spherical Torus eXperiment Upgrade device. Actuation is obtained using the momentum from six injected neutral beams and the neoclassical toroidal viscosity generated by applying three-dimensional magnetic fields. Based on a model of the momentum diffusion and torque balance, a feedback controller is designed and tested in closed-loop simulations using TRANSP, a time dependent transport analysis code, in predictive mode. Promising results for the ongoing experimental implementation of controllers are obtained. PMID:28435207

Simultaneous feedback control of plasma rotation and stored energy on NSTX-U using neoclassical toroidal viscosity and neutral beam injection

DOE PAGES

Goumiri, I. R.; Rowley, C. W.; Sabbagh, S. A.; ...

2017-02-23

In this study, a model-based feedback system is presented enabling the simultaneous control of the stored energy through β n and the toroidal rotation profile of the plasma in National Spherical Torus eXperiment Upgrade device. Actuation is obtained using the momentum from six injected neutral beams and the neoclassical toroidal viscosity generated by applying three-dimensional magnetic fields. Based on a model of the momentum diffusion and torque balance, a feedback controller is designed and tested in closed-loop simulations using TRANSP, a time dependent transport analysis code, in predictive mode. Promising results for the ongoing experimental implementation of controllers are obtained.

Electrowetting (EW)-based valve combined with hydrophilic teflon microfluidic guidance in controlling continuous fluid flow.

PubMed

Cheng, Ji-Yen; Hsiung, Lo-Chang

2004-12-01

Electrowetting (EW)-based techniques have been widely used in manipulating discrete liquid. However, few articles discussed the controlling of continuous fluid flow by using EW-based techniques. In this paper, an EW-based valve combined with plasma-modified Teflon surface, which serves as a microfluidic guidance, in controlling continuous fluid flow has been demonstrated. The plasma-modified Teflon surface is firstly demonstrated for confining continuous fluid flow. The EW-based microfluidic device possesses the functions of a valve and a microchannel without complex moving parts and grooved microchannels. The quantitative characteristics of the EW-based valve are also studied. Propylene carbonate (PC) is firstly demonstrated as the working liquid in the EW-based device because of its applications in parallel oligonucleotide synthesis. It is found that lower valve actuation voltage reduces the deterioration of the valve and improves the valve stability.

Scalable graphene production: perspectives and challenges of plasma applications

NASA Astrophysics Data System (ADS)

Levchenko, Igor; Ostrikov, Kostya (Ken); Zheng, Jie; Li, Xingguo; Keidar, Michael; B. K. Teo, Kenneth

2016-05-01

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h-1 m-2 was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various sizes reaching hundreds of square millimetres, and the thickness varying from a monolayer to 10-20 layers. Additional factors such as electrical voltage and current, not available in thermal CVD processes could potentially lead to better scalability, flexibility and control of the plasma-based processes. Advantages and disadvantages of various systems are also considered.

Scalable graphene production: perspectives and challenges of plasma applications.

PubMed

Levchenko, Igor; Ostrikov, Kostya Ken; Zheng, Jie; Li, Xingguo; Keidar, Michael; B K Teo, Kenneth

2016-05-19

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h(-1) m(-2) was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various sizes reaching hundreds of square millimetres, and the thickness varying from a monolayer to 10-20 layers. Additional factors such as electrical voltage and current, not available in thermal CVD processes could potentially lead to better scalability, flexibility and control of the plasma-based processes. Advantages and disadvantages of various systems are also considered.

Initial experimental test of a helicon plasma based mass filter

NASA Astrophysics Data System (ADS)

Gueroult, R.; Evans, E. S.; Zweben, S. J.; Fisch, N. J.; Levinton, F.

2016-06-01

High throughput plasma mass separation requires rotation control in a high density multi-species plasmas. A preliminary mass separation device based on a helicon plasma operating in gas mixtures and featuring concentric biasable ring electrodes is introduced. Plasma profile shows strong response to electrode biasing. In light of floating potential measurements, the density response is interpreted as the consequence of a reshaping of the radial electric field in the plasma. This field can be made confining or de-confining depending on the imposed potential at the electrodes, in a way which is consistent with single particle orbit radial stability. Concurrent spatially resolved spectroscopic measurements suggest ion separation, with heavy to light ion emission line ratio increasing with radius when a specific potential gradient is applied to the electrodes.

Cold plasma interactions with plants: Morphing and movements of Venus flytrap and Mimosa pudica induced by argon plasma jet.

PubMed

Volkov, Alexander G; Xu, Kunning G; Kolobov, Vladimir I

2017-12-01

Low temperature (cold) plasma finds an increasing number of applications in biology, medicine and agriculture. In this paper, we report a new effect of plasma induced morphing and movements of Venus flytrap and Mimosa pudica. We have experimentally observed plasma activation of sensitive plant movements and morphing structures in these plants similar to stimulation of their mechanosensors in vivo. Application of an atmospheric pressure argon plasma jet to the inside or outside of a lobe, midrib, or cilia in Dionaea muscipula Ellis induces trap closing. Treatment of Mimosa pudica by plasma induces movements of pinnules and petioles similar to the effects of mechanical stimulation. We have conducted control experiments and simulations to illustrate that gas flow and UV radiation associated with plasma are not the primary reasons for the observed effects. Reactive oxygen and nitrogen species (RONS) produced by cold plasma in atmospheric air appear to be the primary reason of plasma-induced activation of phytoactuators in plants. Some of these RONS are known to be signaling molecules, which control plants' developmental processes. Understanding these mechanisms could promote plasma-based technology for plant developmental control and future use for plant protection from pathogens. Our work offers new insight into mechanisms which trigger plant morphing and movement. Copyright © 2017 Elsevier B.V. All rights reserved.

Can tissue adhesives and platelet-rich plasma prevent pharyngocutaneous fistula formation?

PubMed

Eryılmaz, Aylin; Demirci, Buket; Gunel, Ceren; Kacar Doger, Firuzan; Yukselen, Ozden; Kurt Omurlu, Imran; Basal, Yesim; Agdas, Fatih; Basak, Sema

2016-02-01

One of the frequently encountered disorders of wound healing following laryngectomy is pharyngocutaneous fistula. However, although studies have been performed with the aim of prevention of pharyngocutaneous fistulae, there are very few studies with tissue adhesives and platelet-rich plasma. In this study, our aim was to investigate the histopathologic changes in wound healing caused by various tissue adhesives and platelet-rich plasma, together with their effects on prevention of pharyngocutaneous fistula. 40 male rats were randomly divided into five groups: control, platelet-rich plasma, fibrin tissue adhesive, protein-based albumin glutaraldehyde and synthetic tissue adhesive groups. The pharyngotomy procedure was performed and was sutured. Except the control group, tissue adhesives and platelet-rich plasma were applied. Then, the skin was sutured. On the seventh day, the rats were sacrificed. The skin was opened and pharyngotomy site was assessed in terms of fistulae. The pharyngeal suture line was evaluated histopathologically by using Ehrlich Hunt scale. Inflammatory infiltration was found to be higher in "platelet-rich plasma" group than "fibrin tissue adhesive" and "synthetic tissue adhesive" groups. The fibroblastic activity of "platelet-rich plasma", "fibrin tissue adhesive" and "protein-based albumin glutaraldehyde" groups was higher than the control group. The positive changes created by platelet-rich plasma and fibrin tissue adhesive at the histopathologic level were found together with no detected fistula. Among the study groups, there was no statistical difference for pharyngeal fistula development. This result may be obtained by the small number of animal experiments. These results shed light on the suggestion that platelet-rich plasma and fibrin tissue adhesive can be used in clinical studies to prevent pharyngocutaneous fistula. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Practicality of magnetic compression for plasma density control

DOE PAGES

Gueroult, Renaud; Fisch, Nathaniel J.

2016-03-16

Here, plasma densification through magnetic compression has been suggested for time-resolved control of the wave properties in plasma-based accelerators [P. F. Schmit and N. J. Fisch, Phys. Rev. Lett. 109, 255003 (2012)]. Using particle in cell simulations with real mass ratio, the practicality of large magnetic compression on timescales shorter than the ion gyro-period is investigated. For compression times shorter than the transit time of a compressional Alfven wave across the plasma slab, results show the formation of two counter-propagating shock waves, leading to a highly non-uniform plasma density profile. Furthermore, the plasma slab displays large hydromagnetic like oscillations aftermore » the driving field has reached steady state. Peak compression is obtained when the two shocks collide in the mid-plane. At this instant, very large plasma heating is observed, and the plasmaβ is estimated to be about 1. Although these results point out a densification mechanism quite different and more complex than initially envisioned, these features still might be advantageous in particle accelerators.« less

Human plasma metabolic profiles of benzydamine, a flavin-containing monooxygenase probe substrate, simulated with pharmacokinetic data from control and humanized-liver mice.

PubMed

Yamazaki-Nishioka, Miho; Shimizu, Makiko; Suemizu, Hiroshi; Nishiwaki, Megumi; Mitsui, Marina; Yamazaki, Hiroshi

2018-02-01

1. Benzydamine is used clinically as a nonsteroidal anti-inflammatory drug in oral rinses and is employed in preclinical research as a flavin-containing monooxygenase (FMO) probe substrate. In this study, plasma concentrations of benzydamine and its primary N-oxide and N-demethylated metabolites were investigated in control TK-NOG mice, in humanized-liver mice, and in mice whose liver cells had been ablated with ganciclovir. 2. Following oral administration of benzydamine (10 mg/kg) in humanized-liver TK-NOG mice, plasma concentrations of benzydamine N-oxide were slightly higher than those of demethyl benzydamine. In contrast, in control and ganciclovir-treated TK-NOG mice, concentrations of demethyl benzydamine were slightly higher than those of benzydamine N-oxide. 3. Simulations of human plasma concentrations of benzydamine and its N-oxide were achieved using simplified physiologically based pharmacokinetic models based on data from control TK-NOG mice and from reported benzydamine concentrations after low-dose administration in humans. Estimated clearance rates based on data from humanized-liver and ganciclovir-treated TK-NOG mice were two orders magnitude high. 4. The pharmacokinetic profiles of benzydamine were different for control and humanized-liver TK-NOG mice. Humanized-liver mice are generally accepted human models; however, drug oxidation in mouse kidney might need to be considered when probe substrates undergo FMO-dependent drug oxidation in mouse liver and kidney.

Plasma effects on the passive external thermal control coating of Space Station Freedom

NASA Technical Reports Server (NTRS)

Carruth, Ralph, Jr.; Vaughn, Jason A.; Holt, James M.; Werp, Richard; Sudduth, Richard D.

1992-01-01

The current baseline chromic acid anodized thermal control coating on 6061-T6 aluminum meteoroid debris (M/D) shields for SSF has been evaluated. The degradation of the solar absorptance, alpha, and the thermal emittance, epsilon, of chromic acid anodized aluminum due to dielectric breakdown in plasma was measured to predict the on-orbit lifetime of the SSF M/D shields. The lifetime of the thermal control coating was based on the surface temperatures achieved with degradation of the thermal control properties, alpha and epsilon. The temperatures of each M/D shield from first element launch (FEL) through FEL+15 years were analyzed. It is shown that the baseline thermal control coating cannot withstand the -140 V potential between the conductive structure of the SSF and the current plasma environment.

On Antimatter and Cosmology.

PubMed

Kevane, C J

1961-02-24

A cosmological model based on a gravitational plasma of matter and antimatter is discussed. The antigravitational interaction of matter and antimatter leads to segregation and an expansion of the plasma universe. The expansion time scale is controlled by the aggregation time scale.

Optimized plasma actuation on asymmetric vortex over a slender body

NASA Astrophysics Data System (ADS)

Long, Yuexiao; Li, Huaxing; Meng, Xuanshi; Hu, Haiyang

2018-01-01

Detailed particle-image-velocimetry and surface pressure measurements are conducted to study asymmetric vortex control over a slender body at high angles of attack by using a pair of optimized alternating current surface-dielectric-barrier discharge plasma actuators. The Reynolds number based on the base diameter of the model is ReD = 3.8 × 105. Steady and duty-cycle manipulations are employed. The results demonstrate the effectiveness of the optimized actuator with a thick Teflon barrier at a high free-stream speed. Perfect linear proportional control is also achieved under duty-cycle control with a reduced frequency of f+ = 0.17.

Atomic precision etch using a low-electron temperature plasma

NASA Astrophysics Data System (ADS)

Dorf, L.; Wang, J.-C.; Rauf, S.; Zhang, Y.; Agarwal, A.; Kenney, J.; Ramaswamy, K.; Collins, K.

2016-03-01

Sub-nm precision is increasingly being required of many critical plasma etching processes in the semiconductor industry. Accurate control over ion energy and ion/radical composition is needed during plasma processing to meet these stringent requirements. Described in this work is a new plasma etch system which has been designed with the requirements of atomic precision plasma processing in mind. In this system, an electron sheet beam parallel to the substrate surface produces a plasma with an order of magnitude lower electron temperature Te (~ 0.3 eV) and ion energy Ei (< 3 eV without applied bias) compared to conventional radio-frequency (RF) plasma technologies. Electron beam plasmas are characterized by higher ion-to-radical fraction compared to RF plasmas, so a separate radical source is used to provide accurate control over relative ion and radical concentrations. Another important element in this plasma system is low frequency RF bias capability which allows control of ion energy in the 2-50 eV range. Presented in this work are the results of etching of a variety of materials and structures performed in this system. In addition to high selectivity and low controllable etch rate, an important requirement of atomic precision etch processes is no (or minimal) damage to the remaining material surface. It has traditionally not been possible to avoid damage in RF plasma processing systems, even during atomic layer etch. The experiments for Si etch in Cl2 based plasmas in the aforementioned etch system show that damage can be minimized if the ion energy is kept below 10 eV. Layer-by-layer etch of Si is also demonstrated in this etch system using electrical and gas pulsing.

Patterned graphene functionalization via mask-free scanning of micro-plasma jet under ambient condition

NASA Astrophysics Data System (ADS)

Ye, Dong; Wu, Shu-Qun; Yu, Yao; Liu, Lin; Lu, Xin-Pei; Wu, Yue

2014-03-01

In this work, a mask-free method is introduced for patterned nitrogen doping of graphene using a micro-plasma jet under ambient condition. Raman and X-ray photoelectron spectroscopy spectra indicate that nitrogen atoms are incorporated into the graphene lattice with the two-dimensional spatial distribution precisely controlled in the range of mm down to 10 μm. Since the chemistry of the micro-plasma jet can be controlled by the choice of the gas mixture, this direct writing process with micro-plasma jet can be a versatile approach for patterned functionalization of graphene with high spatial resolution. This could have promising applications in graphene-based electronics.

Closed loop adaptive control of spectrum-producing step using neural networks

DOEpatents

Fu, Chi Yung

1998-01-01

Characteristics of the plasma in a plasma-based manufacturing process step are monitored directly and in real time by observing the spectrum which it produces. An artificial neural network analyzes the plasma spectrum and generates control signals to control one or more of the process input parameters in response to any deviation of the spectrum beyond a narrow range. In an embodiment, a plasma reaction chamber forms a plasma in response to input parameters such as gas flow, pressure and power. The chamber includes a window through which the electromagnetic spectrum produced by a plasma in the chamber, just above the subject surface, may be viewed. The spectrum is conducted to an optical spectrometer which measures the intensity of the incoming optical spectrum at different wavelengths. The output of optical spectrometer is provided to an analyzer which produces a plurality of error signals, each indicating whether a respective one of the input parameters to the chamber is to be increased or decreased. The microcontroller provides signals to control respective controls, but these lines are intercepted and first added to the error signals, before being provided to the controls for the chamber. The analyzer can include a neural network and an optional spectrum preprocessor to reduce background noise, as well as a comparator which compares the parameter values predicted by the neural network with a set of desired values provided by the microcontroller.

Closed loop adaptive control of spectrum-producing step using neural networks

DOEpatents

Fu, C.Y.

1998-11-24

Characteristics of the plasma in a plasma-based manufacturing process step are monitored directly and in real time by observing the spectrum which it produces. An artificial neural network analyzes the plasma spectrum and generates control signals to control one or more of the process input parameters in response to any deviation of the spectrum beyond a narrow range. In an embodiment, a plasma reaction chamber forms a plasma in response to input parameters such as gas flow, pressure and power. The chamber includes a window through which the electromagnetic spectrum produced by a plasma in the chamber, just above the subject surface, may be viewed. The spectrum is conducted to an optical spectrometer which measures the intensity of the incoming optical spectrum at different wavelengths. The output of optical spectrometer is provided to an analyzer which produces a plurality of error signals, each indicating whether a respective one of the input parameters to the chamber is to be increased or decreased. The microcontroller provides signals to control respective controls, but these lines are intercepted and first added to the error signals, before being provided to the controls for the chamber. The analyzer can include a neural network and an optional spectrum preprocessor to reduce background noise, as well as a comparator which compares the parameter values predicted by the neural network with a set of desired values provided by the microcontroller. 7 figs.

Soft X-ray tomography in support of impurity control in tokamaks

NASA Astrophysics Data System (ADS)

Mlynar, J.; Mazon, D.; Imrisek, M.; Loffelmann, V.; Malard, P.; Odstrcil, T.; Tomes, M.; Vezinet, D.; Weinzettl, V.

2016-10-01

This contribution reviews an important example of current developments in diagnostic systems and data analysis tools aimed at improved understanding and control of transport processes in magnetically confined high temperature plasmas. The choice of tungsten for the plasma facing components of ITER and probably also DEMO means that impurity control in fusion plasmas is now a crucial challenge. Soft X-ray (SXR) diagnostic systems serve as a key sensor for experimental studies of plasma impurity transport with a clear prospective of its control via actuators based mainly on plasma heating systems. The SXR diagnostic systems typically feature high temporal resolution but limited spatial resolution due to access restrictions. In order to reconstruct the spatial distribution of the SXR radiation from line integrated measurements, appropriate tomographic methods have been developed and validated, while novel numerical methods relevant for real-time control have been proposed. Furthermore, in order to identify the main contributors to the SXR plasma radiation, at least partial control over the spectral sensitivity range of the detectors would be beneficial, which motivates for developments of novel SXR diagnostic methods. Last, but not least, semiconductor photosensitive elements cannot survive in harsh conditions of future fusion reactors due to radiation damage, which calls for development of radiation hard SXR detectors. Present research in this field is exemplified on recent results from tokamaks COMPASS, TORE SUPRA and the Joint European Torus JET. Further planning is outlined.

Effective utilization of ozone in plasma-based advanced oxidation process

NASA Astrophysics Data System (ADS)

Takeuchi, Nozomi; Ishibashi, Naoto; Sugiyama, Tsuyoshi; Kim, Hyun-Ha

2018-05-01

Decomposition of acetic acid in water was conducted using multiple plasmas generated within oxygen bubbles. Ballast capacitors were used to control the plasma input power, allowing hydrogen peroxide and ozone to be produced at different rates in each plasma by adjusting the capacitance. By using an ozone absorber connected to the plasma reactor, OH radicals, both generated by the plasmas directly and reproduced from hydrogen peroxide through reactions with ozone, could be effectively utilized for the reduction of total organic carbon (TOC). Under the condition with the highest ozone production rate, higher processing speed and energy efficiency for the TOC reduction were achieved compared with other plasma methods.

Advanced Method of Boundary-Layer Control Based on Localized Plasma Generation

DTIC Science & Technology

2009-05-01

measurements, validation of experiments, wind-tunnel testing of the microwave / plasma generation system , preliminary assessment of energy required...and design of a microwave generator , electrodynamic and multivibrator systems for experiments in the IHM-NAU wind tunnel: MW generator and its high...equipped with the microwave - generation and protection systems to study advanced methods of flow control (Kiev) Fig. 2.1,a. The blade

Plasma Onco-Immunotherapy: Novel Approach to Cancer Treatment

NASA Astrophysics Data System (ADS)

Fridman, Alexander

2015-09-01

Presentation is reviewing the newest results obtained by researchers of A.J. Drexel Plasma Institute on direct application of non-thermal plasma for direct treatment of different types of cancer by means of specific stimulation of immune system in the frameworks of the so-called onco-immunotherapy. Especial attention is paid to analysis of depth of penetration of different plasma-medical effects, from ROS, RNS, and ions to special biological signaling and immune system related processes. General aspects of the plasma-stimulation of immune system are discussed, pointing out specific medical applications. Most of experiments have been carried out using nanosecond pulsed DBD at low power and relatively low level of treatment doses, guaranteeing non-damage no-toxicity treatment regime. The nanosecond pulsed DBD physics is discussed mostly regarding its space uniformity and control of plasma parameters relevant to plasma medical treatment, and especially relevant to depth of penetration of different plasma medical effects. Detailed mechanism of the plasma-induced onco-immunotherapy has been suggested based upon preliminary in-vitro experiments with DBD treatment of different cancer cells. Sub-elements of this mechanism related to activation of macrophages and dendritic cells, specific stressing of cancer cells and the immunogenic cell death (ICD) are to be discussed based on results of corresponding in-vitro experiments. In-vivo experiments focused on the plasma-induced onco-immunotherapy were carried out in collaboration with medical doctors from Jefferson University hospital of Philadelphia. Todays achievements and nearest future prospective of clinical test focused on plasma-controlled cancer treatment are discussed in conclusion.

Sensitive Detection of Colorectal Cancer in Peripheral Blood by Septin 9 DNA Methylation Assay

PubMed Central

Grützmann, Robert; Molnar, Bela; Pilarsky, Christian; Habermann, Jens K.; Schlag, Peter M.; Saeger, Hans D.; Miehlke, Stephan; Stolz, Thomas; Model, Fabian; Roblick, Uwe J.; Bruch, Hans-Peter; Koch, Rainer; Liebenberg, Volker; deVos, Theo; Song, Xiaoling; Day, Robert H.; Sledziewski, Andrew Z.; Lofton-Day, Catherine

2008-01-01

Background Colorectal cancer (CRC) is the second leading cause of cancer deaths despite the fact that detection of this cancer in early stages results in over 90% survival rate. Currently less than 45% of at-risk individuals in the US are screened regularly, exposing a need for better screening tests. We performed two case-control studies to validate a blood-based test that identifies methylated DNA in plasma from all stages of CRC. Methodology/Principal Findings Using a PCR assay for analysis of Septin 9 (SEPT9) hypermethylation in DNA extracted from plasma, clinical performance was optimized on 354 samples (252 CRC, 102 controls) and validated in a blinded, independent study of 309 samples (126 CRC, 183 controls). 168 polyps and 411 additional disease controls were also evaluated. Based on the training study SEPT9-based classification detected 120/252 CRCs (48%) and 7/102 controls (7%). In the test study 73/126 CRCs (58%) and 18/183 control samples (10%) were positive for SEPT9 validating the training set results. Inclusion of an additional measurement replicate increased the sensitivity of the assay in the testing set to 72% (90/125 CRCs detected) while maintaining 90% specificity (19/183 for controls). Positive rates for plasmas from the other cancers (11/96) and non-cancerous conditions (41/315) were low. The rate of polyp detection (>1 cm) was ∼20%. Conclusions/Significance Analysis of SEPT9 DNA methylation in plasma represents a straightforward, minimally invasive method to detect all stages of CRC with potential to satisfy unmet needs for increased compliance in the screening population. Further clinical testing is warranted. PMID:19018278

Active control of massively separated high-speed/base flows with electric arc plasma actuators

NASA Astrophysics Data System (ADS)

DeBlauw, Bradley G.

The current project was undertaken to evaluate the effects of electric arc plasma actuators on high-speed separated flows. Two underlying goals motivated these experiments. The first goal was to provide a flow control technique that will result in enhanced flight performance for supersonic vehicles by altering the near-wake characteristics. The second goal was to gain a broader and more sophisticated understanding of these complex, supersonic, massively-separated, compressible, and turbulent flow fields. The attainment of the proposed objectives was facilitated through energy deposition from multiple electric-arc plasma discharges near the base corner separation point. The control authority of electric arc plasma actuators on a supersonic axisymmetric base flow was evaluated for several actuator geometries, frequencies, forcing modes, duty cycles/on-times, and currents. Initially, an electric arc plasma actuator power supply and control system were constructed to generate the arcs. Experiments were performed to evaluate the operational characteristics, electromagnetic emission, and fluidic effect of the actuators in quiescent ambient air. The maximum velocity induced by the arc when formed in a 5 mm x 1.6 mm x 2 mm deep cavity was about 40 m/s. During breakdown, the electromagnetic emission exhibited a rise and fall in intensity over a period of about 340 ns. After breakdown, the emission stabilized to a near-constant distribution. It was also observed that the plasma formed into two different modes: "high-voltage" and "low-voltage". It is believed that the plasma may be switching between an arc discharge and a glow discharge for these different modes. The two types of plasma do not appear to cause substantial differences on the induced fluidic effects of the actuator. In general, the characterization study provided a greater fundamental understanding of the operation of the actuators, as well as data for computational model comparison. Preliminary investigations of actuator geometry in the supersonic base flow determined that inclined cavity and normal cavity actuators positioned on the base near the base edge could produce significant disturbances in the shear layer. The disturbances were able to be tracked in time with phase-locked schlieren imaging and particle image velocimetry (PIV). The final set of flow control experiments were therefore performed with an eight-actuator base using the inclined cavity actuator geometry. The actuators were able to cause moderate influences on the axisymmetric shear layer velocity profile and base pressure. The most substantial changes to the shear layer and base pressure were noted for the highest current and duty cycle tests. At 1 A and 20% duty cycle, the base pressure was reduced by 3.5%. Similar changes were noted for all modes and a range of frequencies from about 10-30 kHz. Increases in duty cycle between 4% and 20% caused a nearly linear decrease in base pressure. Analysis of the shear layer velocity profiles acquired through PIV show a local thickening of the shear layer in the region of the disturbances caused by the actuator. A slight increase in thickness was also observed away from the disturbance. Disturbances were able to be tracked at all frequencies and translated along the shear layer at a convective velocity of 430 +/- 20 m/s. A fairly clear trend of increasing velocity disturbance amplitude correlating to increasing base pressure changes was noted. Moreover, the ability of the disturbances to stay well organized further down the shear layer also appears to be a significant factor in the actuators' effect on base pressure. Consistent with these observations, it appears that increased duty cycle causes increased shear layer disturbance amplitudes. The use of PIV has enabled substantial insight to be gained into the effects of the actuators on the ensemble-averaged flow field and on the variability of the instantaneous flow field with and without control. A sensitive bimodal recirculation region behavior was found in the no-control flow field that the plasma actuators could force. The flow field and turbulence statistics in each mode were substantially different. Through analysis of past no-control base pressure measurements, it is believed that the bimodal behavior fluctuates at a characteristic frequency between 0.4 and 0.5 Hz [StD = [special character omitted](5x10-5)]. The flat time-averaged base pressure distribution is due to the superposition of a normally non-flat instantaneous base pressure distribution. Also, the standard deviation of the base pressure measurements is reduced when in one recirculation region mode as compared to when it is fluctuating between recirculation region modes.

Recommendations for Improving Identification and Quantification in Non-Targeted, GC-MS-Based Metabolomic Profiling of Human Plasma

PubMed Central

Wang, Hanghang; Muehlbauer, Michael J.; O’Neal, Sara K.; Newgard, Christopher B.; Hauser, Elizabeth R.; Shah, Svati H.

2017-01-01

The field of metabolomics as applied to human disease and health is rapidly expanding. In recent efforts of metabolomics research, greater emphasis has been placed on quality control and method validation. In this study, we report an experience with quality control and a practical application of method validation. Specifically, we sought to identify and modify steps in gas chromatography-mass spectrometry (GC-MS)-based, non-targeted metabolomic profiling of human plasma that could influence metabolite identification and quantification. Our experimental design included two studies: (1) a limiting-dilution study, which investigated the effects of dilution on analyte identification and quantification; and (2) a concentration-specific study, which compared the optimal plasma extract volume established in the first study with the volume used in the current institutional protocol. We confirmed that contaminants, concentration, repeatability and intermediate precision are major factors influencing metabolite identification and quantification. In addition, we established methods for improved metabolite identification and quantification, which were summarized to provide recommendations for experimental design of GC-MS-based non-targeted profiling of human plasma. PMID:28841195

Collaborative Research: Fundamental studies of plasma control using surface embedded electronic devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raja, Laxminarayan L.; PanneerChelvam, PremKumar; Levko, Dimtry

2016-02-26

The proposed study will investigate the effect of active electron injection of from electrode surfaces To the best of our knowledge, no such a study has ever been attempted even though it could lead to the formation of whole new classes of plasma based devices and systems. We are motivated by recent articles and simple theory which gives strong reason to believe that embedded electronic devices can be used to exert control over the SEE coefficient of semiconductor surfaces (and maybe other surface types as well). Furthermore, the research will explore how such sub-surface electronic devices can best be usedmore » to exert control over an associated plasma.« less

Initial experimental test of a helicon plasma based mass filter

DOE PAGES

Gueroult, R.; Evans, E. S.; Zweben, S. J.; ...

2016-05-12

High throughput plasma mass separation requires rotation control in a high density multi-species plasmas. A preliminary mass separation device based on a helicon plasma operating in gas mixtures and featuring concentric biasable ring electrodes is introduced. Plasma profile shows strong response to electrode biasing. In light of floating potential measurements, the density response is interpreted as the consequence of a reshaping of the radial electric field in the plasma. This field can be made confining or de-confining depending on the imposed potential at the electrodes, in a way which is consistent with single particle orbit radial stability. In conclusion, concurrentmore » spatially resolved spectroscopic measurements suggest ion separation, with heavy to light ion emission line ratio increasing with radius when a specific potential gradient is applied to the electrodes.« less

Low plasma levels of cholecalciferol and 13-cis-retinoic acid in tuberculosis: implications in host-based chemotherapy.

PubMed

Srinivasan, Anand; Syal, Kirtimaan; Banerjee, Dibyajyoti; Hota, Debasish; Gupta, Dheeraj; Kaul, Deepak; Chakrabarti, Amitava

2013-10-01

The aim of this study was to estimate the concentration of cholecalciferol and 13-cis-retinoic acid (RA) in the plasma and pleural fluid of patients with tuberculosis (TB) against controls. Plasma levels of cholecalciferol and 13-cis-RA were measured in 22 patients with TB and healthy controls and their pleural fluids levels were measured in 6 TB patients and diseased controls by established high-performance liquid chromatography-based procedure. Cholecalciferol levels in plasma and pleural fluid of patients with TB and healthy controls were 67.45 (10.71) nmol/L and 21.40 (8.58) nmol/L compared with 117.43 (18.40) nmol/L (P < 0.001) and 94.73 (33.34) nmol/L (P = 0.0049), respectively. 13-cis-RA level in the plasma of patients with TB and healthy controls were 1.51 (0.72) nmol/L and 6.67 (0.81) nmol/L (P < 0.001), respectively. 13-cis-RA was not detectable in pleural fluid. The levels of both the agents were lower in patients with TB than in controls. It was observed that in patients with TB there is a combined deficiency of cholecalciferol and 13-cis-RA compared with healthy volunteers. Because cholecalciferol and 13-cis-RA are in equilibrium with active ingredients of vitamins A and D, we feel that there is a combined deficiency of these vitamins in patients with TB. There is an evidence that concomitant vitamin A and D supplementation can kill intracellular Mycobacterium tuberculosis in vitro. Therefore, the observations made in this study can pave the path for a trial of combined supplementation of available formulations of vitamin A and D (cholecalciferol and 13-cis-RA) for novel anti-tubercular drug therapy. Because such an approach is host-based it has potential to treat even multidrug-resistant and extensively drug-resistant forms of TB. Copyright © 2013 Elsevier Inc. All rights reserved.

Optical Plasma Control During ARC Carbon Nanotube Growth

NASA Technical Reports Server (NTRS)

Hinkov, I.; Farhat, S.; DeLaChapelle, M. Lamy; Fan, S. S.; Han, H. X.; Li, G. H.; Scott, C. D.

2001-01-01

To improve nanotube production, we developed a novel optical control technique, based on the shape of the visible plasma zone created between the anode and the cathode in the direct current (DC) arc process. For a given inert gas, we adjust the anode to cathode distance (ACD) in order to obtain strong visible vortices around the cathode. This enhance anode vaporization, which improve nanotubes formation. In light of our experimental results, we focus our discussion on the relationship between plasma parameters and nanotube growth. Plasma temperature control during arc process is achieved using argon, helium, and their mixtures as a buffer gases. The variation of the gas mixture from pure argon to pure helium changes plasma temperature. As a consequence, the microscopic characteristics of nanotubes as diameter distribution is changed moving from smaller values for argon to higher diameters for helium. We also observe a dependence of the macroscopic characteristics of the final products as Brunauer-Emmett-Teller (BET) surface area.

Sunitinib-ibuprofen drug interaction affects the pharmacokinetics and tissue distribution of sunitinib to brain, liver, and kidney in male and female mice differently.

PubMed

Lau, Christine Li Ling; Chan, Sook Tyng; Selvaratanam, Manimegahlai; Khoo, Hui Wen; Lim, Adeline Yi Ling; Modamio, Pilar; Mariño, Eduardo L; Segarra, Ignacio

2015-08-01

Tyrosine kinase inhibitor sunitinib (used in GIST, advanced RCC, and pancreatic neuroendocrine tumors) undergoes CYP3A4 metabolism and is an ABCB1B and ABCG2 efflux transporters substrate. We assessed the pharmacokinetic interaction with ibuprofen (an NSAID used by patients with cancer) in Balb/c male and female mice. Mice (study group) were coadministered (30 min apart) 30 mg/kg of ibuprofen and 60 mg/kg of sunitinib PO and compared with the control groups, which received sunitinib alone (60 mg/kg, PO). Sunitinib concentration in plasma, brain, kidney, and liver was measured by HPLC as scheduled and noncompartmental pharmacokinetic parameters estimated. In female control mice, sunitinib AUC0→∞ decreased in plasma (P < 0.05), was higher in liver and brain (P < 0.001), and lower in kidney (P < 0.001) vs. male control mice. After ibuprofen coadministration, female mice showed lower AUC0→∞ in plasma (P < 0.01), brain, liver, and kidney (all P < 0.001). However, in male mice, AUC0→∞ remained unchanged in plasma, increased in liver and kidney, and decreased in brain (all P < 0.001). The tissue-to-plasma AUC0→∞ ratio was similar between male and female control mice, but changed after ibuprofen coadministration: Male mice showed 1.6-fold higher liver-to-plasma ratio (P < 0.001) while remained unchanged in female mice and in kidney (male and female mice) but decreased 55% in brain (P < 0.05). The tissue-to-plasma partial AUC ratio, the drug tissue targeting index, and the tissue-plasma hysteresis-like plots also showed sex-based ibuprofen-sunitinib drug interaction differences. The results illustrate the relevance of this DDI on sunitinib pharmacokinetics and tissue uptake. These may be due to gender-based P450 and efflux/transporters differences. © 2015 Société Française de Pharmacologie et de Thérapeutique.

Effects of a healthy Nordic diet on plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome: a randomized, [corrected] controlled trial (SYSDIET).

PubMed

Brader, Lea; Rejnmark, Lars; Carlberg, Carsten; Schwab, Ursula; Kolehmainen, Marjukka; Rosqvist, Fredrik; Cloetens, Lieselotte; Landin-Olsson, Mona; Gunnarsdottir, Ingibjorg; Poutanen, Kaisa S; Herzig, Karl-Heinz; Risérus, Ulf; Savolainen, Markku J; Thorsdottir, Inga; Uusitupa, Matti; Hermansen, Kjeld

2014-06-01

At northern latitudes, vitamin D is not synthesized endogenously during winter, causing low plasma 25-hydroxyvitamin D (25(OH)D) concentrations. Therefore, we evaluated the effects of a healthy Nordic diet based on Nordic nutrition recommendations (NNR) on plasma 25(OH)D and explored its dietary predictors. In a Nordic multi-centre trial, subjects (n = 213) with metabolic syndrome were randomized to a control or a healthy Nordic diet favouring fish (≥300 g/week, including ≥200 g/week fatty fish), whole-grain products, berries, fruits, vegetables, rapeseed oil and low-fat dairy products. Plasma 25(OH)D and parathyroid hormone were analysed before and after 18- to 24-week intervention. At baseline, 45 % had vitamin D inadequacy (<50 nmol/l), whereas 8 % had deficiency (<25 nmol/l). Dietary vitamin D intake was increased by the healthy Nordic diet (P < 0.001). The healthy Nordic and the control diet reduced the prevalence of vitamin D inadequacy by 42 % (P < 0.001) and 19 % (P = 0.002), respectively, without between-group difference (P = 0.142). Compared with control, plasma 25(OH)D (P = 0.208) and parathyroid hormone (P = 0.207) were not altered by the healthy Nordic diet. Predictors for 25(OH)D were intake of vitamin D, eicosapentaenoic acids (EPA), docosahexaenoic acids (DHA), vitamin D supplement, plasma EPA and plasma DHA. Nevertheless, only vitamin D intake and season predicted the 25(OH)D changes. Consuming a healthy Nordic diet based on NNR increased vitamin D intake but not plasma 25(OH)D concentration. The reason why fish consumption did not improve vitamin D status might be that many fish are farmed and might contain little vitamin D or that frying fish may result in vitamin D extraction. Additional ways to improve vitamin D status in Nordic countries may be needed.

Pre-Results of the Real-Time ODIN Validation on MARTe Using Plasma Linearized Model in FTU Tokamak

NASA Astrophysics Data System (ADS)

Sadeghi, Yahya; Boncagni, Luca

2012-06-01

MARTe is a modular framework for real-time control aspects. At present time there are several MARTe systems under development at Frascati Tokamak Upgrade (Boncagni et al. in First steps in the FTU migration towards a modular and distributed real time control architecture based on MARTe and RTNet, 2010) such as the LH power percentage system, the gas puffing control system, the real-time ODIN plasma equilibrium reconstruction system and the position/current feedback control system (in a design phase) (Boncagni et al. in J Fusion Eng Design). The real-time reconstruction of magnetic flux in FTU tokamak is an important issue to estimate some quantities that can be use to control the plasma. This paper addresses the validation of real-time implementation of that task on MARTe.

Physics-based Control-oriented Modeling of the Current Profile Evolution in NSTX-Upgrade

NASA Astrophysics Data System (ADS)

Ilhan, Zeki; Barton, Justin; Shi, Wenyu; Schuster, Eugenio; Gates, David; Gerhardt, Stefan; Kolemen, Egemen; Menard, Jonathan

2013-10-01

The operational goals for the NSTX-Upgrade device include non-inductive sustainment of high- β plasmas, realization of the high performance equilibrium scenarios with neutral beam heating, and achievement of longer pulse durations. Active feedback control of the current profile is proposed to enable these goals. Motivated by the coupled, nonlinear, multivariable, distributed-parameter plasma dynamics, the first step towards feedback control design is the development of a physics-based, control-oriented model for the current profile evolution in response to non-inductive current drives and heating systems. For this purpose, the nonlinear magnetic-diffusion equation is coupled with empirical models for the electron density, electron temperature, and non-inductive current drives (neutral beams). The resulting first-principles-driven, control-oriented model is tailored for NSTX-U based on the PTRANSP predictions. Main objectives and possible challenges associated with the use of the developed model for control design are discussed. This work was supported by PPPL.

Cold atmospheric pressure plasma jets: Interaction with plasmid DNA and tailored electron heating using dual-frequency excitation

NASA Astrophysics Data System (ADS)

Niemi, K.; O'Neill, C.; Cox, L. J.; Waskoenig, J.; Hyland, W. B.; McMahon, S. J.; Reuter, S.; Currell, F. J.; Graham, W. G.; O'Connell, D.; Gans, T.

2012-05-01

Recent progress in plasma science and technology has enabled the development of a new generation of stable cold non-equilibrium plasmas operating at ambient atmospheric pressure. This opens horizons for new plasma technologies, in particular in the emerging field of plasma medicine. These non-equilibrium plasmas are very efficient sources for energy transport through reactive neutral particles (radicals and metastables), charged particles (ions and electrons), UV radiation, and electro-magnetic fields. The effect of a cold radio frequency-driven atmospheric pressure plasma jet on plasmid DNA has been investigated. The formation of double strand breaks correlates well with the atomic oxygen density. Taken with other measurements, this indicates that neutral components in the jet are effective in inducing double strand breaks. Plasma manipulation techniques for controlled energy delivery are highly desirable. Numerical simulations are employed for detailed investigations of the electron dynamics, which determines the generation of reactive species. New concepts based on nonlinear power dissipation promise superior strategies to control energy transport for tailored technological exploitations.

2D microwave imaging reflectometer electronics.

PubMed

Spear, A G; Domier, C W; Hu, X; Muscatello, C M; Ren, X; Tobias, B J; Luhmann, N C

2014-11-01

A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

Plasma Braking Due to External Magnetic Perturbations

NASA Astrophysics Data System (ADS)

Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

2010-11-01

The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

Alterations in plasma lipid profile patterns in head and neck cancer and oral precancerous conditions.

PubMed

Patel, P S; Shah, M H; Jha, F P; Raval, G N; Rawal, R M; Patel, M M; Patel, J B; Patel, D D

2004-01-01

The changes in lipid profile have long been associated with cancer because lipids play a key role in maintenance of cell integrity. The present study evaluated alterations in plasma lipid profile in untreated head and neck cancer patients as well as patients with oral precancerous conditions (OPC) and its association with habit of tobacco consumption. This hospital-based case control study included 184 head and neck cancer patients, 153 patients with OPC and 52 controls. Plasma lipids including: (i) Total cholesterol, (ii) LDL cholesterol (LDLC), (iii) HDL cholesterol (HDLC) (iv) VLDL cholesterol (VLDLC) and (v) triglycerides were analysed by spectrophotometric kits. Student's t-test was performed to compare mean values of the parameters. A significant decrease in plasma total cholesterol and HDLC was observed in cancer patients (P=0.008 and P=0.000 respectively) as well as in patients with OPC (P=0.014 and P=0.000, respectively) as compared to the controls. The plasma VLDL and triglycerides levels were significantly lower in cancer patients as compared to the patients with OPC (P=0.04) and controls (P=0.059). The tobacco habituates showed lower plasma lipid levels than the non-habituates. Our data strengthen the evidence of an inverse relationship between plasma lipid levels and head and neck malignancies as well as OPC. The lower levels of plasma cholesterol and other lipid constituents in patients might be due to their increased utilization by neoplastic cells for new membrane biogenesis. The findings strongly warrant an in-depth study of alterations in plasma lipid profile in head neck cancer patients.

Cryogenic pellet launcher adapted for controlling of tokamak plasma edge instabilities.

PubMed

Lang, P T; Cierpka, P; Harhausen, J; Neuhauser, J; Wittmann, C; Gál, K; Kálvin, S; Kocsis, G; Sárközi, J; Szepesi, T; Dorner, C; Kauke, G

2007-02-01

One of the main challenges posed recently on pellet launcher systems in fusion-oriented plasma physics is the control of the plasma edge region. Strong energy bursts ejected from the plasma due to edge localized modes (ELMs) can form a severe threat for in-vessel components but can be mitigated by sufficiently frequent triggering of the underlying instabilities using hydrogen isotope pellet injection. However, pellet injection systems developed mainly for the task of ELM control, keeping the unwanted pellet fueling minimized, are still missing. Here, we report on a novel system developed under the premise of its suitability for control and mitigation of plasma edge instabilities. The system is based on the blower gun principle and is capable of combining high repetition rates up to 143 Hz with low pellet velocities. Thus, the flexibility of the accessible injection geometry can be maximized and the pellet size kept low. As a result the new system allows for an enhancement in the tokamak operation as well as for more sophisticated experiments investigating the underlying physics of the plasma edge instabilities. This article reports on the design of the new system, its main operational characteristics as determined in extensive test bed runs, and also its first test at the tokamak experiment ASDEX Upgrade.

Size-controlled growth and antibacterial mechanism for Cu:C nanocomposite thin films.

PubMed

Javid, Amjed; Kumar, Manish; Yoon, Seokyoung; Lee, Jung Heon; Han, Jeon Geon

2016-12-21

The interdependence of 'size' and 'volume-fraction' hinders the identification of their individual role in the interface properties of metal nanoparticles (NPs) embedded in a matrix. Here, the case of Cu NPs embedded in a C matrix is presented for their profound antibacterial activity. Cu:C nanocomposite thin films with fixed Cu content (≈12 atomic%) are prepared using a plasma process where plasma energy controls the size of Cu NPs (from 9 nm to 16 nm). An inverse relationship between the size-effect on antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria is established through the real time monitoring of an aliquot by inductively coupled plasma mass spectrometry, which confirmed the inverse relationship of Cu ion release from the nanocomposite with varied Cu NP sizes. It was found that enhancing the total power density increases the plasma density as well as effective kinetic energy of the plasma species, which in turn creates a large number of nucleation sites and restricts the island kind of growth of Cu NPs. The mechanism of NP size-control is illustrated on the basis of ion density and nucleation and the growth regime of plasma species. This physical approach to NP size reduction anticipates a contamination-free competitive recipe of size-control to capping based chemical methods.

High-performance computing-based exploration of flow control with micro devices.

PubMed

Fujii, Kozo

2014-08-13

The dielectric barrier discharge (DBD) plasma actuator that controls flow separation is one of the promising technologies to realize energy savings and noise reduction of fluid dynamic systems. However, the mechanism for controlling flow separation is not clearly defined, and this lack of knowledge prevents practical use of this technology. Therefore, large-scale computations for the study of the DBD plasma actuator have been conducted using the Japanese Petaflops supercomputer 'K' for three different Reynolds numbers. Numbers of new findings on the control of flow separation by the DBD plasma actuator have been obtained from the simulations, and some of them are presented in this study. Knowledge of suitable device parameters is also obtained. The DBD plasma actuator is clearly shown to be very effective for controlling flow separation at a Reynolds number of around 10(5), and several times larger lift-to-drag ratio can be achieved at higher angles of attack after stall. For higher Reynolds numbers, separated flow is partially controlled. Flow analysis shows key features towards better control. DBD plasma actuators are a promising technology, which could reduce fuel consumption and contribute to a green environment by achieving high aerodynamic performance. The knowledge described above can be obtained only with high-end computers such as the supercomputer 'K'. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Method and platform standardization in MRM-based quantitative plasma proteomics.

PubMed

Percy, Andrew J; Chambers, Andrew G; Yang, Juncong; Jackson, Angela M; Domanski, Dominik; Burkhart, Julia; Sickmann, Albert; Borchers, Christoph H

2013-12-16

There exists a growing demand in the proteomics community to standardize experimental methods and liquid chromatography-mass spectrometry (LC/MS) platforms in order to enable the acquisition of more precise and accurate quantitative data. This necessity is heightened by the evolving trend of verifying and validating candidate disease biomarkers in complex biofluids, such as blood plasma, through targeted multiple reaction monitoring (MRM)-based approaches with stable isotope-labeled standards (SIS). Considering the lack of performance standards for quantitative plasma proteomics, we previously developed two reference kits to evaluate the MRM with SIS peptide approach using undepleted and non-enriched human plasma. The first kit tests the effectiveness of the LC/MRM-MS platform (kit #1), while the second evaluates the performance of an entire analytical workflow (kit #2). Here, these kits have been refined for practical use and then evaluated through intra- and inter-laboratory testing on 6 common LC/MS platforms. For an identical panel of 22 plasma proteins, similar concentrations were determined, regardless of the kit, instrument platform, and laboratory of analysis. These results demonstrate the value of the kit and reinforce the utility of standardized methods and protocols. The proteomics community needs standardized experimental protocols and quality control methods in order to improve the reproducibility of MS-based quantitative data. This need is heightened by the evolving trend for MRM-based validation of proposed disease biomarkers in complex biofluids such as blood plasma. We have developed two kits to assist in the inter- and intra-laboratory quality control of MRM experiments: the first kit tests the effectiveness of the LC/MRM-MS platform (kit #1), while the second evaluates the performance of an entire analytical workflow (kit #2). In this paper, we report the use of these kits in intra- and inter-laboratory testing on 6 common LC/MS platforms. This article is part of a Special Issue entitled: Standardization and Quality Control in Proteomics. © 2013.

Real-time radiative divertor feedback control development for the NSTX-U tokamak using a vacuum ultraviolet spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soukhanovskii, V. A., E-mail: vlad@llnl.gov; Kaita, R.; Stratton, B.

2016-11-15

A radiative divertor technique is planned for the NSTX-U tokamak to prevent excessive erosion and thermal damage of divertor plasma-facing components in H-mode plasma discharges with auxiliary heating up to 12 MW. In the radiative (partially detached) divertor, extrinsically seeded deuterium or impurity gases are used to increase plasma volumetric power and momentum losses. A real-time feedback control of the gas seeding rate is planned for discharges of up to 5 s duration. The outer divertor leg plasma electron temperature T{sub e} estimated spectroscopically in real time will be used as a control parameter. A vacuum ultraviolet spectrometer McPherson Modelmore » 251 with a fast charged-coupled device detector is developed for temperature monitoring between 5 and 30 eV, based on the Δn = 0, 1 line intensity ratios of carbon, nitrogen, or neon ion lines in the spectral range 300–1600 Å. A collisional-radiative model-based line intensity ratio will be used for relative calibration. A real-time T{sub e}-dependent signal within a characteristic divertor detachment equilibration time of ∼10–15 ms is expected.« less

Real-time radiative divertor feedback control development for the NSTX-U tokamak using a vacuum ultraviolet spectrometer

DOE PAGES

Soukhanovskii, V. A.; Kaita, R.; Stratton, B.

2016-08-04

Here, a radiative divertor technique is planned for the NSTX-U tokamak to prevent excessive erosion and thermal damage of divertor plasma-facing components in H-mode plasma discharges with auxiliary heating up to 12 MW. In the radiative (partially detached) divertor, extrinsically seeded deuterium or impurity gases are used to increase plasma volumetric power and momentum losses. A real-time feedback control of the gas seeding rate is planned for discharges of up to 5 s duration. The outer divertor leg plasma electron temperature T e estimated spectroscopically in real time will be used as a control parameter. A vacuum ultraviolet spectrometer McPhersonmore » Model 251 with a fast charged-coupled device detector is developed for temperature monitoring between 5 and 30 eV, based on the Δn = 0, 1 line intensity ratios of carbon, nitrogen, or neon ion lines in the spectral range 300–1600 Å. A collisional-radiative model-based line intensity ratio will be used for relative calibration. A real-time T e-dependent signal within a characteristic divertor detachment equilibration time of ~10–15 ms is expected.« less

Quantification of plasma phosphorylated tau to use as a biomarker for brain Alzheimer pathology: pilot case-control studies including patients with Alzheimer's disease and down syndrome.

PubMed

Tatebe, Harutsugu; Kasai, Takashi; Ohmichi, Takuma; Kishi, Yusuke; Kakeya, Tomoshi; Waragai, Masaaki; Kondo, Masaki; Allsop, David; Tokuda, Takahiko

2017-09-04

There is still a substantial unmet need for less invasive and lower-cost blood-based biomarkers to detect brain Alzheimer's disease (AD) pathology. This study is aimed to determine whether quantification of plasma tau phosphorylated at threonine 181 (p-tau181) is informative in the diagnosis of AD. We have developed a novel ultrasensitive immunoassay to quantify plasma p-tau181, and measured the levels of plasma p-tau181 in three cohorts. In the first cohort composed of 20 AD patients and 15 age-matched controls, the plasma levels of p-tau181 were significantly higher in the AD patients than those in the controls (0.171 ± 0.166 pg/ml in AD versus 0.0405 ± 0.0756 pg/ml in controls, p = 0.0039). The percentage of the subjects whose levels of plasma p-tau181 exceeded the cut-off value (0.0921 pg/ml) was significantly higher in the AD group compared with the control group (60% in AD versus 16.7% in controls, p = 0.0090). In the second cohort composed of 20 patients with Down syndrome (DS) and 22 age-matched controls, the plasma concentrations of p-tau181 were significantly higher in the DS group (0.767 ± 1.26 pg/ml in DS versus 0.0415 ± 0.0710 pg/ml in controls, p = 0.0313). There was a significant correlation between the plasma levels of p-tau181 and age in the DS group (R 2  = 0.4451, p = 0.0013). All of the DS individuals showing an extremely high concentration of plasma p-tau181 (> 1.0 pg/ml) were older than the age of 40. In the third cohort composed of 8 AD patients and 3 patients with other neurological diseases, the levels of plasma p-tau181 significantly correlated with those of CSF p-tau181 (R 2  = 0.4525, p = 0.023). We report for the first time quantitative data on the plasma levels of p-tau181 in controls and patients with AD and DS, and these data suggest that the plasma p-tau181 is a promising blood biomarker for brain AD pathology. This exploratory pilot study warrants further large-scale and well-controlled studies to validate the usefulness of plasma p-tau181 as an urgently needed surrogate marker for the diagnosis and disease progression of AD.

Conference on Real-Time Computer Applications in Nuclear, Particle and Plasma Physics, 6th, Williamsburg, VA, May 15-19, 1989, Proceedings

NASA Technical Reports Server (NTRS)

Pordes, Ruth (Editor)

1989-01-01

Papers on real-time computer applications in nuclear, particle, and plasma physics are presented, covering topics such as expert systems tactics in testing FASTBUS segment interconnect modules, trigger control in a high energy physcis experiment, the FASTBUS read-out system for the Aleph time projection chamber, a multiprocessor data acquisition systems, DAQ software architecture for Aleph, a VME multiprocessor system for plasma control at the JT-60 upgrade, and a multiasking, multisinked, multiprocessor data acquisition front end. Other topics include real-time data reduction using a microVAX processor, a transputer based coprocessor for VEDAS, simulation of a macropipelined multi-CPU event processor for use in FASTBUS, a distributed VME control system for the LISA superconducting Linac, a distributed system for laboratory process automation, and a distributed system for laboratory process automation. Additional topics include a structure macro assembler for the event handler, a data acquisition and control system for Thomson scattering on ATF, remote procedure execution software for distributed systems, and a PC-based graphic display real-time particle beam uniformity.

Automated process control for plasma etching

NASA Astrophysics Data System (ADS)

McGeown, Margaret; Arshak, Khalil I.; Murphy, Eamonn

1992-06-01

This paper discusses the development and implementation of a rule-based system which assists in providing automated process control for plasma etching. The heart of the system is to establish a correspondence between a particular data pattern -- sensor or data signals -- and one or more modes of failure, i.e., a data-driven monitoring approach. The objective of this rule based system, PLETCHSY, is to create a program combining statistical process control (SPC) and fault diagnosis to help control a manufacturing process which varies over time. This can be achieved by building a process control system (PCS) with the following characteristics. A facility to monitor the performance of the process by obtaining and analyzing the data relating to the appropriate process variables. Process sensor/status signals are input into an SPC module. If trends are present, the SPC module outputs the last seven control points, a pattern which is represented by either regression or scoring. The pattern is passed to the rule-based module. When the rule-based system recognizes a pattern, it starts the diagnostic process using the pattern. If the process is considered to be going out of control, advice is provided about actions which should be taken to bring the process back into control.

Active control for stabilization of neoclassical tearing modesa)

NASA Astrophysics Data System (ADS)

Humphreys, D. A.; Ferron, J. R.; La Haye, R. J.; Luce, T. C.; Petty, C. C.; Prater, R.; Welander, A. S.

2006-05-01

This work describes active control algorithms used by DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] to stabilize and maintain suppression of 3/2 or 2/1 neoclassical tearing modes (NTMs) by application of electron cyclotron current drive (ECCD) at the rational q surface. The DIII-D NTM control system can determine the correct q-surface/ECCD alignment and stabilize existing modes within 100-500ms of activation, or prevent mode growth with preemptive application of ECCD, in both cases enabling stable operation at normalized beta values above 3.5. Because NTMs can limit performance or cause plasma-terminating disruptions in tokamaks, their stabilization is essential to the high performance operation of ITER [R. Aymar et al., ITER Joint Central Team, ITER Home Teams, Nucl. Fusion 41, 1301 (2001)]. The DIII-D NTM control system has demonstrated many elements of an eventual ITER solution, including general algorithms for robust detection of q-surface/ECCD alignment and for real-time maintenance of alignment following the disappearance of the mode. This latter capability, unique to DIII-D, is based on real-time reconstruction of q-surface geometry by a Grad-Shafranov solver using external magnetics and internal motional Stark effect measurements. Alignment is achieved by varying either the plasma major radius (and the rational q surface) or the toroidal field (and the deposition location). The requirement to achieve and maintain q-surface/ECCD alignment with accuracy on the order of 1cm is routinely met by the DIII-D Plasma Control System and these algorithms. We discuss the integrated plasma control design process used for developing these and other general control algorithms, which includes physics-based modeling and testing of the algorithm implementation against simulations of actuator and plasma responses. This systematic design/test method and modeling environment enabled successful mode suppression by the NTM control system upon first-time use in an experimental discharge.

Characterization of the concurrent metabolic changes in brain and plasma during insulin-induced moderate hypoglycemia using 1H NMR spectroscopy in juvenile rats.

PubMed

Ennis, Kathleen; Lusczek, Elizabeth; Rao, Raghavendra

2017-07-13

Treatment of hypoglycemia in children is currently based on plasma glucose measurements. This approach may not ensure neuroprotection since plasma glucose does not reflect the dynamic state of cerebral energy metabolism. To determine whether cerebral metabolic changes during hypoglycemia could be better characterized using plasma metabolomic analysis, insulin-induced acute hypoglycemia was induced in 4-week-old rats. Brain tissue and concurrent plasma samples were collected from hypoglycemic (N=7) and control (N=7) rats after focused microwave fixation to prevent post-mortem metabolic changes. The concentration of 29 metabolites in brain and 34 metabolites in plasma were determined using 1 H NMR spectroscopy at 700MHz and examined using partial least squares-discriminant analysis. The sensitivity of plasma glucose for detecting cerebral energy failure was assessed by determining its relationship to brain phosphocreatine. The brain and plasma metabolite profiles of the hypoglycemia group were distinct from the control group (brain: R 2 =0.92, Q 2 =0.31; plasma: R 2 =0.95, Q 2 =0.74). Concentration differences in glucose, ketone bodies and amino acids were responsible for the intergroup separation. There was 45% concordance between the brain and plasma metabolite profiles. Brain phosphocreatine correlated with brain glucose (control group: R 2 =0.86; hypoglycemia group: R 2 =0.59; p<0.05), but not with plasma glucose. The results confirm that plasma glucose is an insensitive biomarker of cerebral energy changes during hypoglycemia and suggest that a plasma metabolite profile is superior for monitoring cerebral metabolism. Copyright © 2017 Elsevier B.V. All rights reserved.

Update on the DIII-D ECH system: experiments, gyrotrons, advanced diagnostics, and controls

NASA Astrophysics Data System (ADS)

Lohr, John; Brambila, Rigoberto; Cengher, Mirela; Gorelov, Yuri; Grosnickle, William; Moeller, Charles; Ponce, Dan; Torrezan, Antonio; Ives, Lawrence; Reed, Michael; Blank, Monica; Felch, Kevin; Parisuaña, Claudia; LeViness, Alexandra

2017-08-01

The ECH system on DIII-D is continuing to be upgraded, while simultaneously being operated nearly daily for plasma experiments. The latest major hardware addition is a new 117.5 GHz gyrotron, which generated 1.7 MW for short pulses during factory testing. A new gyrotron control system based on Field Programmable Gate Array (FPGA) technology with very high speed system data acquisition has significantly increased the flexibility and reliability of individual gyrotron operation. We have improved the performance of the fast mirror scanning, both by increasing the scan speeds and by adding new algorithms for controlling the aiming using commands generated by the Plasma Control System (PCS). The system is used for transport studies, ELM control, current profile control, non-inductive current generation, suppression of MHD modes, startup assist, plasma density control, and other applications. A program of protective measures, which has been in place for more than two years, has eliminated damage to hardware and diagnostics caused by overdense operation. Other activities not directly related to fusion research have used the ECH system to test components, study methods for improving production of semiconductor junctions and materials, and test the feasibility of using ground based microwave systems to power satellites into orbit.

Using the Multipole Resonance Probe to Stabilize the Electron Density During a Reactive Sputter Process

NASA Astrophysics Data System (ADS)

Oberberg, Moritz; Styrnoll, Tim; Ries, Stefan; Bienholz, Stefan; Awakowicz, Peter

2015-09-01

Reactive sputter processes are used for the deposition of hard, wear-resistant and non-corrosive ceramic layers such as aluminum oxide (Al2O3) . A well known problem is target poisoning at high reactive gas flows, which results from the reaction of the reactive gas with the metal target. Consequently, the sputter rate decreases and secondary electron emission increases. Both parameters show a non-linear hysteresis behavior as a function of the reactive gas flow and this leads to process instabilities. This work presents a new control method of Al2O3 deposition in a multiple frequency CCP (MFCCP) based on plasma parameters. Until today, process controls use parameters such as spectral line intensities of sputtered metal as an indicator for the sputter rate. A coupling between plasma and substrate is not considered. The control system in this work uses a new plasma diagnostic method: The multipole resonance probe (MRP) measures plasma parameters such as electron density by analyzing a typical resonance frequency of the system response. This concept combines target processes and plasma effects and directly controls the sputter source instead of the resulting target parameters.

Cytomegalovirus (CMV) DNA load in plasma for the diagnosis of CMV disease before engraftment in hematopoietic stem-cell transplant recipients.

PubMed

Limaye, A P; Huang, M L; Leisenring, W; Stensland, L; Corey, L; Boeckh, M

2001-02-01

Among hematopoietic stem-cell transplant (HSCT) recipients, cytomegalovirus (CMV) disease before engraftment is rare but often fatal, and cell-based diagnostic tests have low sensitivity in this clinical setting. We used the quantitative real-time polymerase chain reaction (PCR) assay to test for CMV DNA in plasma samples from 15 HSCT recipients who developed CMV disease before engraftment and from 33 matched control patients. CMV DNA was detected in plasma in 14 (93.3%) of the 15 patients who had CMV disease before engraftment, compared with 5 (15.2%) of 33 control patients (P<.001). CMV DNA was detected a median of 13 days before the onset of CMV disease (range, 0-35 days). The maximum CMV virus load in plasma was >1 log(10) higher among case patients than among control patients (median, 1700 [range, 50 to 5.5x107] vs. <50 [range, <50-350] CMV DNA copies/mL plasma, respectively; P<.001). Quantitative PCR for CMV DNA in plasma appears to be useful for the identification of HSCT recipients at risk for CMV disease before engraftment.

Plasma homocysteine is associated with increased oxidative stress and antioxidant enzyme activity in welders.

PubMed

Liu, Hung-Hsin; Shih, Tung-Sheng; Huang, Hsin-Ru; Huang, Shih-Chien; Lee, Lien-Hsiung; Huang, Yi-Chia

2013-01-01

The purpose of this study was to examine the association of vitamin B6 status and plasma homocysteine with oxidative stress and antioxidant capacities in welders. Workers were divided into either the welding exposure group (n = 57) or the nonexposure controls (n = 42) based on whether they were employed as welders. There were no significant differences in vitamin B₆ status and plasma homocysteine concentration between the welding exposure group and the nonexposure controls. The welding exposure group had significantly higher levels of oxidized low-density lipoprotein cholesterol and lower erythrocyte glutathione concentration and superoxide dismutase (SOD) activities when compared to nonexposure controls. Plasma pyridoxal 5'-phosphate concentration did not correlate with oxidative stress indicators or antioxidant capacities in either group. However, plasma homocysteine significantly correlated with total antioxidant capacity (TAC) (partial r(s) = -0.34, P < 0.05) and erythrocyte SOD activities (partial r(s) = 0.29, P < 0.05) after adjusting for potential confounders in the welding exposure group. In the welding exposure group, adequate vitamin B₆ status was not associated with oxidative stress or antioxidant capacities. However, elevated plasma homocysteine seemed to be a major contributing factor to antioxidant capacities (TAC and erythrocyte SOD activities) in welders.

Magnetotail energy dissipation during an auroral substorm

PubMed Central

Panov, E.V.; Baumjohann, W.; Wolf, R.A.; Nakamura, R.; Angelopoulos, V.; Weygand, J. M.; Kubyshkina, M.V.

2016-01-01

Violent releases of space plasma energy from the Earth’s magnetotail during substorms produce strong electric currents and bright aurora. But what modulates these currents and aurora and controls dissipation of the energy released in the ionosphere? Using data from the THEMIS fleet of satellites and ground-based imagers and magnetometers, we show that plasma energy dissipation is controlled by field-aligned currents (FACs) produced and modulated during magnetotail topology change and oscillatory braking of fast plasma jets at 10-14 Earth radii in the nightside magnetosphere. FACs appear in regions where plasma sheet pressure and flux tube volume gradients are non-collinear. Faster tailward expansion of magnetotail dipolarization and subsequent slower inner plasma sheet restretching during substorm expansion and recovery phases cause faster poleward then slower equatorward movement of the substorm aurora. Anharmonic radial plasma oscillations build up displaced current filaments and are responsible for discrete longitudinal auroral arcs that move equatorward at a velocity of about 1km/s. This observed auroral activity appears sufficient to dissipate the released energy. PMID:27917231

Plasma treatments of wool fiber surface for microfluidic applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeon, So-Hyoun; Hwang, Ki-Hwan; Lee, Jin Su

Highlights: • We used atmospheric plasma for tuning the wettability of wool fibers. • The wicking rates of the wool fibers increased with increasing treatment time. • The increasing of wettability results in removement of fatty acid on the wool surface. - Abstract: Recent progress in health diagnostics has led to the development of simple and inexpensive systems. Thread-based microfluidic devices allow for portable and inexpensive field-based technologies enabling medical diagnostics, environmental monitoring, and food safety analysis. However, controlling the flow rate of wool thread, which is a very important part of thread-based microfluidic devices, is quite difficult. For thismore » reason, we focused on thread-based microfluidics in the study. We developed a method of changing the wettability of hydrophobic thread, including wool thread. Thus, using natural wool thread as a channel, we demonstrate herein that the manipulation of the liquid flow, such as micro selecting and micro mixing, can be achieved by applying plasma treatment to wool thread. In addition to enabling the flow control of the treated wool channels consisting of all natural substances, this procedure will also be beneficial for biological sensing devices. We found that wools treated with various gases have different flow rates. We used an atmospheric plasma with O{sub 2}, N{sub 2} and Ar gases.« less

Current drive for stability of thermonuclear plasma reactor

NASA Astrophysics Data System (ADS)

Amicucci, L.; Cardinali, A.; Castaldo, C.; Cesario, R.; Galli, A.; Panaccione, L.; Paoletti, F.; Schettini, G.; Spigler, R.; Tuccillo, A.

2016-01-01

To produce in a thermonuclear fusion reactor based on the tokamak concept a sufficiently high fusion gain together stability necessary for operations represent a major challenge, which depends on the capability of driving non-inductive current in the hydrogen plasma. This request should be satisfied by radio-frequency (RF) power suitable for producing the lower hybrid current drive (LHCD) effect, recently demonstrated successfully occurring also at reactor-graded high plasma densities. An LHCD-based tool should be in principle capable of tailoring the plasma current density in the outer radial half of plasma column, where other methods are much less effective, in order to ensure operations in the presence of unpredictably changes of the plasma pressure profiles. In the presence of too high electron temperatures even at the periphery of the plasma column, as envisaged in DEMO reactor, the penetration of the coupled RF power into the plasma core was believed for long time problematic and, only recently, numerical modelling results based on standard plasma wave theory, have shown that this problem should be solved by using suitable parameter of the antenna power spectrum. We show here further information on the new understanding of the RF power deposition profile dependence on antenna parameters, which supports the conclusion that current can be actively driven over a broad layer of the outer radial half of plasma column, thus enabling current profile control necessary for the stability of a reactor.

Effect of nonsinusoidal bias waveforms on ion energy distributions and fluorocarbon plasma etch selectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwal, Ankur; Kushner, Mark J.; Iowa State University, Department of Electrical and Computer Engineering, 104 Marston Hall, Ames, Iowa 50011-2151

2005-09-15

The distributions of ion energies incident on the wafer significantly influence feature profiles and selectivity during plasma etching. Control of ion energies is typically obtained by varying the amplitude or frequency of a radio frequency sinusoidal bias voltage applied to the substrate. The resulting ion energy distribution (IED), though, is generally broad. Controlling the width and shape of the IED can potentially improve etch selectivity by distinguishing between threshold energies of surface processes. In this article, control of the IED was computationally investigated by applying a tailored, nonsinusoidal bias waveform to the substrate of an inductively coupled plasma. The waveformmore » we investigated, a quasi-dc negative bias having a short positive pulse each cycle, produced a narrow IED whose width was controllable based on the length of the positive spike and frequency. We found that the selectivity between etching Si and SiO{sub 2} in fluorocarbon plasmas could be controlled by adjusting the width and energy of the IED. Control of the energy of a narrow IED enables etching recipes that transition between speed and selectivity without change of gas mixture.« less

Metabolic profiles of pomalidomide in human plasma simulated with pharmacokinetic data in control and humanized-liver mice.

PubMed

Shimizu, Makiko; Suemizu, Hiroshi; Mitsui, Marina; Shibata, Norio; Guengerich, F Peter; Yamazaki, Hiroshi

2017-10-01

1. Pomalidomide has been shown to be potentially teratogenic in thalidomide-sensitive animal species such as rabbits. Screening for thalidomide analogs devoid of teratogenicity/toxicity - attributable to metabolites formed by cytochrome P450 enzymes - but having immunomodulatory properties is a strategic pathway towards development of new anticancer drugs. 2. In this study, plasma concentrations of pomalidomide, its primary 5-hydroxylated metabolite, and its glucuronide conjugate(s) were investigated in control and humanized-liver mice. Following oral administration of pomalidomide (100 mg/kg), plasma concentrations of 7-hydroxypomalidomide and 5-hydroxypomalidomide glucuronide were slightly higher in humanized-liver mice than in control mice. 3. Simulations of human plasma concentrations of pomalidomide were achieved with simplified physiologically-based pharmacokinetic models in both groups of mice in accordance with reported pomalidomide concentrations after low dose administration in humans. 4. The results indicate that pharmacokinetic profiles of pomalidomide were roughly similar between control mice and humanized-liver mice and that control and humanized-liver mice mediated pomalidomide 5-hydroxylation in vivo. Introducing one aromatic amino group into thalidomide resulted in less species differences in in vivo pharmacokinetics in control and humanized-liver mice.

Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hidding, B.; Rosenzweig, J. B.; Xi, Y.

2012-12-21

An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojanmore » Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.« less

Standardized protocols for quality control of MRM-based plasma proteomic workflows.

PubMed

Percy, Andrew J; Chambers, Andrew G; Smith, Derek S; Borchers, Christoph H

2013-01-04

Mass spectrometry (MS)-based proteomics is rapidly emerging as a viable technology for the identification and quantitation of biological samples, such as human plasma--the most complex yet commonly employed biofluid in clinical analyses. The transition from a qualitative to quantitative science is required if proteomics is going to successfully make the transition to a clinically useful technique. MS, however, has been criticized for a lack of reproducibility and interlaboratory transferability. Currently, the MS and plasma proteomics communities lack standardized protocols and reagents to ensure that high-quality quantitative data can be accurately and precisely reproduced by laboratories across the world using different MS technologies. Toward addressing this issue, we have developed standard protocols for multiple reaction monitoring (MRM)-based assays with customized isotopically labeled internal standards for quality control of the sample preparation workflow and the MS platform in quantitative plasma proteomic analyses. The development of reference standards and their application to a single MS platform is discussed herein, along with the results from intralaboratory tests. The tests highlighted the importance of the reference standards in assessing the efficiency and reproducibility of the entire bottom-up proteomic workflow and revealed errors related to the sample preparation and performance quality and deficits of the MS and LC systems. Such evaluations are necessary if MRM-based quantitative plasma proteomics is to be used in verifying and validating putative disease biomarkers across different research laboratories and eventually in clinical laboratories.

In vitro treatment of Candida albicans biofilms on denture base material with volume dielectric barrier discharge plasma (VDBD) compared with common chemical antiseptics.

PubMed

Matthes, Rutger; Jablonowski, Lukasz; Koban, Ina; Quade, Antje; Hübner, Nils-Olaf; Schlueter, Rabea; Weltmann, Klaus-Dieter; von Woedtke, Thomas; Kramer, Axel; Kocher, Thomas

2015-12-01

To prevent oral candidiasis, it is crucial to inactivate Candida-based biofilms on dentures. Common denture cleansing solutions cannot sufficiently inactivate Candida albicans. Therefore, we investigated the anticandidal efficacy of a physical plasma against C. albicans biofilms in vitro. Argon or argon plasma with 1 % oxygen admixture was applied on C. albicans biofilms grown for 2, 7, or 16 days on polymethylmethacrylate discs; 0.1 % chlorhexidine digluconate (CHX) and 0.6 % sodium hypochlorite (NaOCl) solutions served as positive treatment controls. In addition, these two solutions were applied in combination with plasma for 30 min to assess potential synergistic effects. The anticandidal efficacy was determined by the number of colony forming units (CFU) in log(10) and expressed as reduction factor (RF, the difference between control and treated specimen). On 2-day-biofilms, plasma treatment alone or combined with 30 min CHX treatment led to significant differences of means of CFU (RF = 4.2 and RF = 4.3), clearly superior to CHX treatment alone (RF = 0.6). Plasma treatment of 7-day-or 16-day-old biofilms revealed no significant CFU reduction. The treatment of 7-day-old (RF = 1.7) and 16-day-old (RF = 1.3) biofilms was slightly more effective with NaOCl alone than with the combined treatment of NaOCl and plasma (RF = 1.6/RF = 1.9). The combination of CHX and plasma increased the RF immaterially. The use of plasma alone and in combination with antiseptics is promising anticandidal regimens for daily use on dentures when biofilms are not older than 2 days. Plasma could help to reduce denture-associated candidiasis.

Steady state compact toroidal plasma production

DOEpatents

Turner, William C.

1986-01-01

Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

Plasma metabolic profiling of dairy cows affected with clinical ketosis using LC/MS technology.

PubMed

Li, Y; Xu, C; Xia, C; Zhang, Hy; Sun, Lw; Gao, Y

2014-01-01

Ketosis in dairy cattle is an important metabolic disorder. Currently, the plasma metabolic profile of ketosis as determined using liquid chromatography-mass spectrometry (LC/MS) has not been reported. To investigate plasma metabolic profiles from cows with clinical ketosis in comparison to control cows. Twenty Holstein dairy cows were divided into two groups based on clinical signs and plasma β-hydroxybutyric acid and glucose concentrations 7-21 days postpartum: clinical ketosis and control cows. Plasma metabolic profiles were analyzed using LC/MS. Data were processed using principal component analysis and orthogonal partial least-squares discriminant analysis. Compared to control cows, the levels of valine, glycine, glycocholic, tetradecenoic acid, and palmitoleic acid increased significantly in clinical ketosis. On the other hand, the levels of arginine, aminobutyric acid, leucine/isoleucine, tryptophan, creatinine, lysine, norcotinine, and undecanoic acid decreased markedly. Our results showed that the metabolic changes in cows with clinical ketosis involve complex metabolic networks and signal transduction. These results are important for future studies elucidating the pathogenesis, diagnosis, and prevention of clinical ketosis in dairy cows.

Robust Low-Cost Cathode for Commercial Applications

NASA Technical Reports Server (NTRS)

Patterson, Michael J.

2007-01-01

Under funding from the NASA Commercial Technology Office, a cathode assembly was designed, developed, fabricated, and tested for use in plasma sources for ground-based materials processing applications. The cathode development activity relied on the large prior NASA investment and successful development of high-current, high-efficiency, long-life hollow cathodes for use on the International Space Station Plasma Contactor System. The hollow cathode was designed and fabricated based on known engineering criteria and manufacturing processes for compatibility with the requirements of the plasma source. The transfer of NASA GRC-developed hollow cathode technology for use as an electron emitter in the commercial plasma source is anticipated to yield a significant increase in process control, while eliminating the present issues of electron emitter lifetime and contamination.

An arc control and protection system for the JET lower hybrid antenna based on an imaging system.

PubMed

Figueiredo, J; Mailloux, J; Kirov, K; Kinna, D; Stamp, M; Devaux, S; Arnoux, G; Edwards, J S; Stephen, A V; McCullen, P; Hogben, C

2014-11-01

Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is one of the additional heating systems at JET. It comprises 24 microwave generators (klystrons, operating at 3.7 GHz) providing up to 5 MW of heating and current drive to the JET plasma. This is done through an antenna composed of an array of waveguides facing the plasma. The protection system presented here is based primarily on an imaging arc detection and real time control system. It has adapted the ITER like wall hotspot protection system using an identical CCD camera and real time image processing unit. A filter has been installed to avoid saturation and spurious system triggers caused by ionization light. The antenna is divided in 24 Regions Of Interest (ROIs) each one corresponding to one klystron. If an arc precursor is detected in a ROI, power is reduced locally with subsequent potential damage and plasma disruption avoided. The power is subsequently reinstated if, during a defined interval of time, arcing is confirmed not to be present by image analysis. This system was successfully commissioned during the restart phase and beginning of the 2013 scientific campaign. Since its installation and commissioning, arcs and related phenomena have been prevented. In this contribution we briefly describe the camera, image processing, and real time control systems. Most importantly, we demonstrate that an LH antenna arc protection system based on CCD camera imaging systems works. Examples of both controlled and uncontrolled LH arc events and their consequences are shown.

Surface Dielectric Barrier Discharge Jet for Skin Disinfection

NASA Astrophysics Data System (ADS)

Creyghton, Yves; Meijer, Rogier; Verweij, Paul; van der Zanden, Frank; Leenders, Paul

A consortium consisting of the research institute TNO, the medical ­university and hospital St Radboud and two industrial enterprises is working on a non-thermal plasma treatment method for hand disinfection. The group is seeking for cooperation, in particular in the field of validation methods and potential ­standardization for plasma based disinfection procedures. The present paper describes technical progress in plasma source development together with initial microbiological data. Particular properties of the sheet shaped plasma volume are the possibility of treating large irregular surfaces in a short period of time, effective plasma produced species transfer to the surface together with high controllability of the nature of plasma species by means of temperature conditioning.

GPUbased, Microsecond Latency, HectoChannel MIMO Feedback Control of Magnetically Confined Plasmas

NASA Astrophysics Data System (ADS)

Rath, Nikolaus

Feedback control has become a crucial tool in the research on magnetic confinement of plasmas for achieving controlled nuclear fusion. This thesis presents a novel plasma feedback control system that, for the first time, employs a Graphics Processing Unit (GPU) for microsecond-latency, real-time control computations. This novel application area for GPU computing is opened up by a new system architecture that is optimized for low-latency computations on less than kilobyte sized data samples as they occur in typical plasma control algorithms. In contrast to traditional GPU computing approaches that target complex, high-throughput computations with massive amounts of data, the architecture presented in this thesis uses the GPU as the primary processing unit rather than as an auxiliary of the CPU, and data is transferred from A-D/D-A converters directly into GPU memory using peer-to-peer PCI Express transfers. The described design has been implemented in a new, GPU-based control system for the High-Beta Tokamak - Extended Pulse (HBT-EP) device. The system is built from commodity hardware and uses an NVIDIA GeForce GPU and D-TACQ A-D/D-A converters providing a total of 96 input and 64 output channels. The system is able to run with sampling periods down to 4 μs and latencies down to 8 μs. The GPU provides a total processing power of 1.5 x 1012 floating point operations per second. To illustrate the performance and versatility of both the general architecture and concrete implementation, a new control algorithm has been developed. The algorithm is designed for the control of multiple rotating magnetic perturbations in situations where the plasma equilibrium is not known exactly and features an adaptive system model: instead of requiring the rotation frequencies and growth rates embedded in the system model to be set a priori, the adaptive algorithm derives these parameters from the evolution of the perturbation amplitudes themselves. This results in non-linear control computations with high computational demands, but is handled easily by the GPU based system. Both digital processing latency and an arbitrary multi-pole response of amplifiers and control coils is fully taken into account for the generation of control signals. To separate sensor signals into perturbed and equilibrium components without knowledge of the equilibrium fields, a new separation method based on biorthogonal decomposition is introduced and used to derive a filter that performs the separation in real-time. The control algorithm has been implemented and tested on the new, GPU-based feedback control system of the HBT-EP tokamak. In this instance, the algorithm was set up to control four rotating n = 1 perturbations at different poloidal angles. The perturbations were treated as coupled in frequency but independent in amplitude and phase, so that the system effectively controls a helical n = 1 perturbation with unknown poloidal spectrum. Depending on the plasma's edge safety factor and rotation frequency, the control system is shown to be able to suppress the amplitude of the dominant 8 kHz mode by up to 60% or amplify the saturated amplitude by a factor of up to two. Intermediate feedback phases combine suppression and amplification with a speed up or slow down of the mode rotation frequency. Increasing feedback gain results in the excitation of an additional, slowly rotating 1.4 kHz mode without further effects on the 8 kHz mode. The feedback performance is found to exceed previous results obtained with an FPGA- and Kalman-filter based control system without requiring any tuning of system model parameters. Experimental results are compared with simulations based on a combination of the Boozer surface current model and the Fitzpatrick-Aydemir model. Within the subset of phenomena that can be represented by the model as well as determined experimentally, qualitative agreement is found.

The segmented non-uniform dielectric module design for uniformity control of plasma profile in a capacitively coupled plasma chamber

NASA Astrophysics Data System (ADS)

Xia, Huanxiong; Xiang, Dong; Yang, Wang; Mou, Peng

2014-12-01

Low-temperature plasma technique is one of the critical techniques in IC manufacturing process, such as etching and thin-film deposition, and the uniformity greatly impacts the process quality, so the design for the plasma uniformity control is very important but difficult. It is hard to finely and flexibly regulate the spatial distribution of the plasma in the chamber via controlling the discharge parameters or modifying the structure in zero-dimensional space, and it just can adjust the overall level of the process factors. In the view of this problem, a segmented non-uniform dielectric module design solution is proposed for the regulation of the plasma profile in a CCP chamber. The solution achieves refined and flexible regulation of the plasma profile in the radial direction via configuring the relative permittivity and the width of each segment. In order to solve this design problem, a novel simulation-based auto-design approach is proposed, which can automatically design the positional sequence with multi independent variables to make the output target profile in the parameterized simulation model approximate the one that users preset. This approach employs an idea of quasi-closed-loop control system, and works in an iterative mode. It starts from initial values of the design variable sequences, and predicts better sequences via the feedback of the profile error between the output target profile and the expected one. It never stops until the profile error is narrowed in the preset tolerance.

Optimization and testing of solid thin film lubrication deposition processes

NASA Astrophysics Data System (ADS)

Danyluk, Michael J.

A novel method for testing solid thin films in rolling contact fatigue (RCF) under ultra-high vacuum (UHV) and high rotational speeds (130 Hz) is presented in this thesis. The UHV-RCF platform is used to quantify the adhesion and lubrication aspects of two thin film coatings deposited on ball-bearings using a physical vapor deposition ion plating process. Plasma properties during ion plating were measured using a Langmuir probe and there is a connection between ion flux, film stress, film adhesion, process voltage, pressure, and RCF life. The UHV-RCF platform and vacuum chamber were constructed using off-the-shelf components and 88 RCF tests in high vacuum have been completed. Maximum RCF life was achieved by maintaining an ion flux between 10 13 to 1015 (cm-2 s-1) with a process voltage and pressure near 1.5 kV and 15 mTorr. Two controller schemes were investigated to maintain optimal plasma conditions for maximum RCF life: PID and LQR. Pressure disturbances to the plasma have a detrimental effect on RCF life. Control algorithms that mitigate pressure and voltage disturbances already exist. However, feedback from the plasma to detect disturbances has not been explored related to deposition processes in the thin-film science literature. Manometer based pressure monitoring systems have a 1 to 2 second delay time and are too slow to detect common pressure bursts during the deposition process. Plasma diagnostic feedback is much faster, of the order of 0.1 second. Plasma total-current feedback was used successfully to detect a typical pressure disturbance associated with the ion plating process. Plasma current is related to ion density and process pressure. A real-time control application was used to detect the pressure disturbance by monitoring plasma-total current and converting it to feedback-input to a pressure control system. Pressure overshoot was eliminated using a nominal PID controller with feedback from a plasma-current diagnostic measurement tool.

Fast tomographic methods for the tokamak ISTTOK

NASA Astrophysics Data System (ADS)

Carvalho, P. J.; Thomsen, H.; Gori, S.; Toussaint, U. v.; Weller, A.; Coelho, R.; Neto, A.; Pereira, T.; Silva, C.; Fernandes, H.

2008-04-01

The achievement of long duration, alternating current discharges on the tokamak IST-TOK requires a real-time plasma position control system. The plasma position determination based on magnetic probes system has been found to be inadequate during the current inversion due to the reduced plasma current. A tomography diagnostic has been therefore installed to supply the required feedback to the control system. Several tomographic methods are available for soft X-ray or bolo-metric tomography, among which the Cormack and Neural networks methods stand out due to their inherent speed of up to 1000 reconstructions per second, with currently available technology. This paper discusses the application of these algorithms on fusion devices while comparing performance and reliability of the results. It has been found that although the Cormack based inversion proved to be faster, the neural networks reconstruction has fewer artifacts and is more accurate.

Develop minimum thrustor control laws and select orbits for a geodesy drag-free satellite

NASA Technical Reports Server (NTRS)

Breakwell, J. V.; Debra, D. B.

1974-01-01

The original motivation for studying control laws for pulse plasma systems was based on the improved life characteristics possible with pulse plasma jets. These pulse plasma units are relatively massive compared with cold gas thrustors. As a result, therefore, significant mass savings can be achieved by minimizing the the number of thrustors. The control laws, therefore, were developed for thrust available from two thrustors only. In a spinning satellite, these thrustors are sufficient to completely control the vehicle as long as the spin rate is sufficiently high for a given level of external disturbance. The thrustors are canted so that a component of each is along the plus and minus spin axis. The other component of each thrustor acts in the radial direction. It is sufficient to analyze the behavior in the plane of spin assuming a single thrustor.

Clinical aspects of the control of plasma volume at microgravity and during return to one gravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1996-01-01

Plasma volume is reduced by 10-20% within 24-48 h of exposure to simulated or actual microgravity. The clinical importance of microgravity induced hypovolemia is manifested by its relationship with orthostatic intolerance and reduced maximal oxygen uptake (VO2max) after return to one gravity (1G). Since there is no evidence to suggest that plasma volume reduction during microgravity is associated with thirst or renal dysfunctions, a diuresis induced by an immediate blood volume shift to the central circulation appears responsible for microgravity-induced hypovolemia. Since most astronauts choose to restrict their fluid intake before a space mission, absence of increased urine output during actual space flight may be explained by low central venous pressure (CVP) which accompanies dehydration. Compelling evidence suggests that prolonged reduction in CVP during exposure to microgravity reflects a "resetting" to a lower operating point, which acts to limit plasma volume expansion during attempts to increase fluid intake. In ground based and space flight experiments, successful restoration and maintenance of plasma volume prior to returning to an upright posture may depend upon development of treatments that can return CVP to its baseline IG operating point. Fluid-loading and lower body negative pressure (LBNP) have not proved completely effective in restoring plasma volume, suggesting that they may not provide the stimulus to elevate the CVP operating point. On the other hand, exercise, which can chronically increase CVP, has been effective in expanding plasma volume when combined with adequate dietary intake of fluid and electrolytes. The success of designing experiments to understand the physiological mechanisms of and development of effective counter measures for the control of plasma volume in microgravity and during return to IG will depend upon testing that can be conducted under standardized controlled baseline conditions during both ground-based and space flight investigations.

Optimal Control Techniques for ResistiveWall Modes in Tokamaks

NASA Astrophysics Data System (ADS)

Clement, Mitchell Dobbs Pearson

Tokamaks can excite kink modes that can lock or nearly lock to the vacuum vessel wall, and whose rotation frequencies and growth rates vary in time but are generally inversely proportional to the magnetic flux diffusion time of the vacuum vessel wall. This magnetohydrodynamic (MHD) instability is pressure limiting in tokamaks and is called the Resistive Wall Mode (RWM). Future tokamaks that are expected to operate as fusion reactors will be required to maximize plasma pressure in order to maximize fusion performance. The DIII-D tokamak is equipped with electromagnetic control coils, both inside and outside of its vacuum vessel, which create magnetic fields that are small by comparison to the machine's equilibrium field but are able to dynamically counteract the RWM. Presently for RWM feedback, DIII-D uses its interior control coils using a classical proportional gain only controller to achieve high plasma pressure. Future advanced tokamak designs will not likely have the luxury of interior control coils and a proportional gain algorithm is not expected to be effective with external control coils. The computer code VALEN was designed to calculate the performance of an MHD feedback control system in an arbitrary geometry. VALEN models the perturbed magnetic field from a single MHD instability and its interaction with surrounding conducting structures using a finite element approach. A linear quadratic gaussian (LQG) control, or H 2 optimal control, algorithm based on the VALEN model for RWM feedback was developed for use with DIII-D's external control coil set. The algorithm is implemented on a platform that combines a graphics processing unit (GPU) for real-time control computation with low latency digital input/output control hardware and operates in parallel with the DIII-D Plasma Control System (PCS). Simulations and experiments showed that modern control techniques performed better, using 77% less current, than classical techniques when using coils external to the vacuum vessel for RWM feedback. RWM feedback based on VALEN outperformed a classical control algorithm using external coils to suppress the normalized plasma response to a rotating n=1 perturbation applied by internal coils over a range of frequencies. This study describes the design, development and testing of the GPU based control hardware and algorithm along with its performance during experiment and simulation.

Double-Layered Atmospheric Pressure Plasma Jet

NASA Astrophysics Data System (ADS)

Choi, Jaegu; Matsuo, Keita; Yoshida, Hidekazu; Namihira, Takao; Katsuki, Sunao; Akiyama, Hidenori

2009-08-01

In this paper, we present a double-layered atmospheric pressure plasma jet (DLAPPJ) that is expected to improve conventional single-layered atmospheric pressure plasma jets. With the additional introduction of nitrogen gas into the outer nozzle between the inner and outer tubes, the plasma plume is boosted, resulting in a brighter and longer plasma torch, which may have more radicals and which may broaden the application range of atmospheric pressure plasma jets. The characteristics of the proposed device were investigated with the measurement of the visible torch length, wettability tests and optical emission spectroscopy. The results obtained imply that the DLAPPJ can be used for target-based plasma treatments, that is, (a) oxidation-related applications, such as surface treatment, biological decontamination and apoptosis induction, and (b) nitrification-related applications such as NO generation for wound healing and surface modification, by controlling radicals in plasmas.

MS-based monitoring of proteolytic decay of synthetic reporter peptides for quality control of plasma and serum specimens.

PubMed

Findeisen, Peter; Thumfart, Jörg Oliver; Costina, Victor; Hofheinz, Ralf; Neumaier, Michael

2013-09-01

To determine the preanalytical quality of serum and plasma by monitoring the time-dependent ex vivo decay of a synthetic reporter peptide (RP) with liquid chromatography/mass spectrometry (LC/MS). Serum and plasma specimens were spiked with the RP and proteolytic fragments were monitored with LC/MS at different preanalytical time points ranging from 2 to 24 hours after blood withdrawal. The concentration of fragments changed in a time-dependent manner, and respective peptide profiles were used to classify specimens according to their preanalytical time span. Classification accuracy was high, with values always above 0.89 for areas under receiver operating characteristic curves. This "proteomics degradation clock" can be used to estimate the preanalytical quality of serum and plasma and might have impact on quality control procedures of biobanking repositories.

Role of Frequency Chirp and Energy Flow Directionality in the Strong Coupling Regime of Brillouin-Based Plasma Amplification.

PubMed

Chiaramello, M; Amiranoff, F; Riconda, C; Weber, S

2016-12-02

A detailed analysis is presented of the various stages of strong coupling Brillouin plasma amplification, emphasizing the importance of the chirp which can be of threefold origin: the intrinsic one driven by the amplification process, the one originating from the chirped-pulse-generated laser pulses, and the one associated with the plasma profile. Control of the overall chirp can optimize or quench the energy transfer. The time-dependent phase relation explains the energy flow direction during amplification and is characteristic for this strong coupling process. The study is also of potential importance to understand and maybe control cross-beam-energy transfer in inertial confinement fusion.

Development of ion source with a washer gun for pulsed neutral beam injection.

PubMed

Asai, T; Yamaguchi, N; Kajiya, H; Takahashi, T; Imanaka, H; Takase, Y; Ono, Y; Sato, K N

2008-06-01

A new type of economical neutral beam source has been developed by using a single washer gun, pulsed operation, and a simple electrode system. We replaced the conventional hot filaments for arc-discharge-type plasma formation with a single stainless-steel washer gun, eliminating the entire dc power supply for the filaments and the cooling system for the electrodes. Our initial experiments revealed successful beam extraction up to 10 kV and 8.6 A, based on spatial profile measurements of density and temperature in the plasma source. The system also shows the potential to control the beam profile by controlling the plasma parameters in the ion accumulation chamber.

Highly tunable electronic properties in plasma-synthesized B-doped microcrystalline-to-amorphous silicon nanostructure for solar cell applications

NASA Astrophysics Data System (ADS)

Lim, J. W. M.; Ong, J. G. D.; Guo, Y.; Bazaka, K.; Levchenko, I.; Xu, S.

2017-10-01

Highly controllable electronic properties (carrier mobility and conductivity) were obtained in the sophisticatedly devised, structure-controlled, boron-doped microcrystalline silicon structure. Variation of plasma parameters enabled fabrication of films with the structure ranging from a highly crystalline (89.8%) to semi-amorphous (45.4%) phase. Application of the innovative process based on custom-designed, optimized, remote inductively coupled plasma implied all advantages of the plasma-driven technique and simultaneously avoided plasma-intrinsic disadvantages associated with ion bombardment and overheating. The high degree of SiH4, H2 and B2H6 precursor dissociation ensured very high boron incorporation into the structure, thus causing intense carrier scattering. Moreover, the microcrystalline-to-amorphous phase transition triggered by the heavy incorporation of the boron dopant with increasing B2H6 flow was revealed, thus demonstrating a very high level of the structural control intrinsic to the process. Control over the electronic properties through variation of impurity incorporation enabled tailoring the carrier concentrations over two orders of magnitude (1018-1020 cm-3). These results could contribute to boosting the properties of solar cells by paving the way to a cheap and efficient industry-oriented technique, guaranteeing a new application niche for this new generation of nanomaterials.

Conceptual Design of the ITER Plasma Control System

NASA Astrophysics Data System (ADS)

Snipes, J. A.

2013-10-01

The conceptual design of the ITER Plasma Control System (PCS) has been approved and the preliminary design has begun for the 1st plasma PCS. This is a collaboration of many plasma control experts from existing devices to design and test plasma control techniques applicable to ITER on existing machines. The conceptual design considered all phases of plasma operation, ranging from non-active H/He plasmas through high fusion gain inductive DT plasmas to fully non-inductive steady-state operation, to ensure that the PCS control functionality and architecture can satisfy the demands of the ITER Research Plan. The PCS will control plasma equilibrium and density, plasma heat exhaust, a range of MHD instabilities (including disruption mitigation), and the non-inductive current profile required to maintain stable steady-state scenarios. The PCS architecture requires sophisticated shared actuator management and event handling systems to prioritize control goals, algorithms, and actuators according to dynamic control needs and monitor plasma and plant system events to trigger automatic changes in the control algorithms or operational scenario, depending on real-time operating limits and conditions.

Plasma Homocysteine Is Associated with Increased Oxidative Stress and Antioxidant Enzyme Activity in Welders

PubMed Central

Liu, Hung-Hsin; Shih, Tung-Sheng; Huang, Hsin-Ru; Huang, Shih-Chien; Lee, Lien-Hsiung; Huang, Yi-Chia

2013-01-01

The purpose of this study was to examine the association of vitamin B6 status and plasma homocysteine with oxidative stress and antioxidant capacities in welders. Workers were divided into either the welding exposure group (n = 57) or the nonexposure controls (n = 42) based on whether they were employed as welders. There were no significant differences in vitamin B6 status and plasma homocysteine concentration between the welding exposure group and the nonexposure controls. The welding exposure group had significantly higher levels of oxidized low-density lipoprotein cholesterol and lower erythrocyte glutathione concentration and superoxide dismutase (SOD) activities when compared to nonexposure controls. Plasma pyridoxal 5′-phosphate concentration did not correlate with oxidative stress indicators or antioxidant capacities in either group. However, plasma homocysteine significantly correlated with total antioxidant capacity (TAC) (partial r s = −0.34, P < 0.05) and erythrocyte SOD activities (partial r s = 0.29, P < 0.05) after adjusting for potential confounders in the welding exposure group. In the welding exposure group, adequate vitamin B6 status was not associated with oxidative stress or antioxidant capacities. However, elevated plasma homocysteine seemed to be a major contributing factor to antioxidant capacities (TAC and erythrocyte SOD activities) in welders. PMID:24106453

Associations of circulating plasma microRNAs with age, body mass index and sex in a population-based study.

PubMed

Ameling, Sabine; Kacprowski, Tim; Chilukoti, Ravi Kumar; Malsch, Carolin; Liebscher, Volkmar; Suhre, Karsten; Pietzner, Maik; Friedrich, Nele; Homuth, Georg; Hammer, Elke; Völker, Uwe

2015-10-14

Non-cellular blood circulating microRNAs (plasma miRNAs) represent a promising source for the development of prognostic and diagnostic tools owing to their minimally invasive sampling, high stability, and simple quantification by standard techniques such as RT-qPCR. So far, the majority of association studies involving plasma miRNAs were disease-specific case-control analyses. In contrast, in the present study, plasma miRNAs were analysed in a sample of 372 individuals from a population-based cohort study, the Study of Health in Pomerania (SHIP). Quantification of miRNA levels was performed by RT-qPCR using the Exiqon Serum/Plasma Focus microRNA PCR Panel V3.M covering 179 different miRNAs. Of these, 155 were included in our analyses after quality-control. Associations between plasma miRNAs and the phenotypes age, body mass index (BMI), and sex were assessed via a two-step linear regression approach per miRNA. The first step regressed out the technical parameters and the second step determined the remaining associations between the respective plasma miRNA and the phenotypes of interest. After regressing out technical parameters and adjusting for the respective other two phenotypes, 7, 15, and 35 plasma miRNAs were significantly (q < 0.05) associated with age, BMI, and sex, respectively. Additional adjustment for the blood cell parameters identified 12 and 19 miRNAs to be significantly associated with age and BMI, respectively. Most of the BMI-associated miRNAs likely originate from liver. Sex-associated differences in miRNA levels were largely determined by differences in blood cell parameters. Thus, only 7 as compared to originally 35 sex-associated miRNAs displayed sex-specific differences after adjustment for blood cell parameters. These findings emphasize that circulating miRNAs are strongly impacted by age, BMI, and sex. Hence, these parameters should be considered as covariates in association studies based on plasma miRNA levels. The established experimental and computational workflow can now be used in future screening studies to determine associations of plasma miRNAs with defined disease phenotypes.

Association between plant-based diets and plasma lipids: a systematic review and meta-analysis.

PubMed

Yokoyama, Yoko; Levin, Susan M; Barnard, Neal D

2017-09-01

Although a recent meta-analysis of randomized controlled trials showed that adoption of a vegetarian diet reduces plasma lipids, the association between vegetarian diets and long-term effects on plasma lipids has not been subjected to meta-analysis. The aim was to conduct a systematic review and meta-analysis of observational studies and clinical trials that have examined associations between plant-based diets and plasma lipids. MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for articles published in English until June 2015. The literature was searched for controlled trials and observational studies that investigated the effects of at least 4 weeks of a vegetarian diet on plasma lipids. Two reviewers independently extracted the study methodology and sample size, the baseline characteristics of the study population, and the concentrations and variance measures of plasma lipids. Mean differences in concentrations of plasma lipids between vegetarian and comparison diet groups were calculated. Data were pooled using a random-effects model. Of the 8385 studies identified, 30 observational studies and 19 clinical trials met the inclusion criteria (N = 1484; mean age, 48.6 years). Consumption of vegetarian diets was associated with lower mean concentrations of total cholesterol (-29.2 and -12.5 mg/dL, P < 0.001), low-density lipoprotein cholesterol (-22.9 and -12.2 mg/dL, P < 0.001), and high-density lipoprotein cholesterol (-3.6 and -3.4 mg/dL, P < 0.001), compared with consumption of omnivorous diets in observational studies and clinical trials, respectively. Triglyceride differences were -6.5 (P = 0.092) in observational studies and 5.8 mg/dL (P = 0.090) in intervention trials. Plant-based diets are associated with decreased total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, but not with decreased triglycerides. PROSPERO number CRD42015023783. Available at: https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015023783. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute.

Association between plant-based diets and plasma lipids: a systematic review and meta-analysis

PubMed Central

Yokoyama, Yoko; Levin, Susan M; Barnard, Neal D

2017-01-01

Abstract Context Although a recent meta-analysis of randomized controlled trials showed that adoption of a vegetarian diet reduces plasma lipids, the association between vegetarian diets and long-term effects on plasma lipids has not been subjected to meta-analysis. Objective The aim was to conduct a systematic review and meta-analysis of observational studies and clinical trials that have examined associations between plant-based diets and plasma lipids. Data Sources MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for articles published in English until June 2015. Study Selection The literature was searched for controlled trials and observational studies that investigated the effects of at least 4 weeks of a vegetarian diet on plasma lipids. Data Extraction Two reviewers independently extracted the study methodology and sample size, the baseline characteristics of the study population, and the concentrations and variance measures of plasma lipids. Mean differences in concentrations of plasma lipids between vegetarian and comparison diet groups were calculated. Data were pooled using a random-effects model. Results Of the 8385 studies identified, 30 observational studies and 19 clinical trials met the inclusion criteria (N = 1484; mean age, 48.6 years). Consumption of vegetarian diets was associated with lower mean concentrations of total cholesterol (−29.2 and −12.5 mg/dL, P < 0.001), low-density lipoprotein cholesterol (−22.9 and −12.2 mg/dL, P < 0.001), and high-density lipoprotein cholesterol (−3.6 and −3.4 mg/dL, P < 0.001), compared with consumption of omnivorous diets in observational studies and clinical trials, respectively. Triglyceride differences were −6.5 (P = 0.092) in observational studies and 5.8 mg/dL (P = 0.090) in intervention trials. Conclusions Plant-based diets are associated with decreased total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, but not with decreased triglycerides. Systematic Review Registration PROSPERO number CRD42015023783. Available at: https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015023783. PMID:28938794

Simulation of magnetic island dynamics under resonant magnetic perturbation with the TEAR code and validation of the results on T-10 tokamak data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivanov, N. V.; Kakurin, A. M.

2014-10-15

Simulation of the magnetic island evolution under Resonant Magnetic Perturbation (RMP) in rotating T-10 tokamak plasma is presented with intent of TEAR code experimental validation. In the T-10 experiment chosen for simulation, the RMP consists of a stationary error field, a magnetic field of the eddy current in the resistive vacuum vessel and magnetic field of the externally applied controlled halo current in the plasma scrape-off layer (SOL). The halo-current loop consists of a rail limiter, plasma SOL, vacuum vessel, and external part of the circuit. Effects of plasma resistivity, viscosity, and RMP are taken into account in the TEARmore » code based on the two-fluid MHD approximation. Radial distribution of the magnetic flux perturbation is calculated with account of the externally applied RMP. A good agreement is obtained between the simulation results and experimental data for the cases of preprogrammed and feedback-controlled halo current in the plasma SOL.« less

Power supply and impedance matching to drive technological radio-frequency plasmas with customized voltage waveforms.

PubMed

Franek, James; Brandt, Steven; Berger, Birk; Liese, Martin; Barthel, Matthias; Schüngel, Edmund; Schulze, Julian

2015-05-01

We present a novel radio-frequency (RF) power supply and impedance matching to drive technological plasmas with customized voltage waveforms. It is based on a system of phase-locked RF generators that output single frequency voltage waveforms corresponding to multiple consecutive harmonics of a fundamental frequency. These signals are matched individually and combined to drive a RF plasma. Electrical filters are used to prevent parasitic interactions between the matching branches. By adjusting the harmonics' phases and voltage amplitudes individually, any voltage waveform can be approximated as a customized finite Fourier series. This RF supply system is easily adaptable to any technological plasma for industrial applications and allows the commercial utilization of process optimization based on voltage waveform tailoring for the first time. Here, this system is tested on a capacitive discharge based on three consecutive harmonics of 13.56 MHz. According to the Electrical Asymmetry Effect, tuning the phases between the applied harmonics results in an electrical control of the DC self-bias and the mean ion energy at almost constant ion flux. A comparison with the reference case of an electrically asymmetric dual-frequency discharge reveals that the control range of the mean ion energy can be significantly enlarged by using more than two consecutive harmonics.

Investigation of Metabolomic Blood Biomarkers for Detection of Adenocarcinoma Lung Cancer

PubMed Central

Fahrmann, Johannes F.; Kim, Kyoungmi; DeFelice, Brian C.; Taylor, Sandra L.; Gandara, David R.; Yoneda, Ken Y.; Cooke, David T.; Fiehn, Oliver; Kelly, Karen; Miyamoto, Suzanne

2015-01-01

Background Untargeted metabolomics was utilized in case control studies of adenocarcinoma (ADC) lung cancer in order to develop and test metabolite classifiers in serum and plasma as potential biomarkers for diagnosing lung cancer. Methods Serum and plasma were collected and used in two independent case-control studies (ADC1 and ADC2). Controls were frequency matched for gender, age and smoking history. There were 52 ADC cases and 31 controls in ADC1 and 43 ADC cases and 43 controls in ADC2. Metabolomics was conducted using gas chromatography time-of-flight mass spectrometry. Differential analysis was performed on ADC1 and the top candidates (FDR < 0.05) for serum and plasma used to develop individual and multiplex-classifiers that were then tested on an independent set of serum and plasma samples (ADC2). Results Aspartate provided the best accuracy (81.4%) for an individual metabolite classifier in serum whereas pyrophosphate had the best accuracy (77.9%) in plasma when independently tested. Multiplex classifiers of either 2 or 4 serum metabolites had an accuracy of 72.7% when independently tested. For plasma, a multi-metabolite classifier consisting of 8 metabolites gave an accuracy of 77.3% when independently tested. Comparison of overall diagnostic performance between the two blood matrices yielded similar performances. However, serum is most ideal given higher sensitivity for low abundant metabolites. Conclusion This study shows the potential of metabolite-based diagnostic tests for detection of lung adenocarcinoma. Further validation in a larger pool of samples is warranted. Impact These biomarkers could improve early detection and diagnosis of lung cancer. PMID:26282632

Performance assessment of a glucose control protocol in septic patients with an automated intermittent plasma glucose monitoring device.

PubMed

Umbrello, M; Salice, V; Spanu, P; Formenti, P; Barassi, A; Melzi d'Eril, G V; Iapichino, G

2014-10-01

The optimal level and modality of glucose control in critically ill patients is still debated. A protocolized approach and the use of nearly-continuous technologies are recommended to manage hyperglycemia, hypoglycemia and glycemic variability. We recently proposed a pato-physiology-based glucose control protocol which takes into account patient glucose/carbohydrate intake and insulin resistance. Aim of the present investigation was to assess the performance of our protocol with an automated intermittent plasma glucose monitoring device (OptiScanner™ 5000). OptiScanner™ was used in 6 septic patients, providing glucose measurement every 15' from a side-port of an indwelling central venous catheter. Target level of glucose was 80-150 mg/dL. Insulin infusion and kcal with nutritional support were also recorded. 6 septic patients were studied for 319 h (1277 measurements); 58 [45-65] hours for each patient (measurements/patient: 231 [172-265]). Blood glucose was at target for 93 [90-98]% of study time. Mean plasma glucose was 126 ± 11 mg/dL. Only 3 hypoglycemic episodes (78, 78, 69 mg/dL) were recorded. Glucose variability was limited: plasma glucose coefficient of variation was 11.7 ± 4.0% and plasma glucose standard deviation was 14.3 ± 5.5 mg/dL. The local glucose control protocol achieved satisfactory glucose control in septic patients along with a high degree of safeness. Automated intermittent plasma glucose monitoring seemed useful to assess the performance of the protocol. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Development of a real-time system for ITER first wall heat load control

NASA Astrophysics Data System (ADS)

Anand, Himank; de Vries, Peter; Gribov, Yuri; Pitts, Richard; Snipes, Joseph; Zabeo, Luca

2017-10-01

The steady state heat flux on the ITER first wall (FW) panels are limited by the heat removal capacity of the water cooling system. In case of off-normal events (e.g. plasma displacement during H-L transitions), the heat loads are predicted to exceed the design limits (2-4.7 MW/m2). Intense heat loads are predicted on the FW, even well before the burning plasma phase. Thus, a real-time (RT) FW heat load control system is mandatory from early plasma operation of the ITER tokamak. A heat load estimator based on the RT equilibrium reconstruction has been developed for the plasma control system (PCS). A scheme, estimating the energy state for prescribed gaps defined as the distance between the last closed flux surface (LCFS)/separatrix and the FW is presented. The RT energy state is determined by the product of a weighted function of gap distance and the power crossing the plasma boundary. In addition, a heat load estimator assuming a simplified FW geometry and parallel heat transport model in the scrape-off layer (SOL), benchmarked against a full 3-D magnetic field line tracer is also presented.

Turbulent Flow Modification With Thermoacoustic Waves for Separation Control

DTIC Science & Technology

2017-08-24

analyses using two different approaches in order to provide guidance to physics-based design of active flow control using thermal-based actuators. RPPR... control effects are also observed by Post & Corke (2004) on the same airfoil. The uses of plasma actuators on other shear layer setups have been...region may be a more practical approach than introducing control inputs externally. On the other hand, Barone & Lele (2005) studied the receptivity of the

Detection of gastric cancer-associated microRNAs on microRNA microarray comparing pre- and post-operative plasma

PubMed Central

Konishi, H; Ichikawa, D; Komatsu, S; Shiozaki, A; Tsujiura, M; Takeshita, H; Morimura, R; Nagata, H; Arita, T; Kawaguchi, T; Hirashima, S; Fujiwara, H; Okamoto, K; Otsuji, E

2012-01-01

Background: Recently, it was reported that plasma microRNAs (miRNAs) are low-invasive useful biomarkers for cancer. We attempted to isolate gastric cancer (GC)-associated miRNAs comparing pre- and post-operative paired plasma, thereby excluding the possible effects of individual variability. Methods: This study was divided into four steps: (1) microarray analysis comparing pre- and post-operative plasma; (2) validation of candidate miRNAs by quantitative RT–PCR; (3) validation study of selected miRNAs using paired plasma; and (4) comparison of the levels of selected miRNAs in plasma between healthy controls and patients. Results: From the results of microarray analysis, nine candidate miRNAs the levels of which were markedly decreased in post-operative plasma were selected for further studies. After confirmation of their post-operative marked reduction, two candidate miRNAs, miR-451 and miR-486, were selected as plasma biomarkers, considering the abundance in plasma, and marked decrease in post-operative samples. In validation, the two miRNAs were found to decrease in post-operative plasma in 90 and 93% of patients (both P<0.01). In comparison with healthy controls, the levels of both miRNAs were found to be significantly higher in patients, and the area under the curve values were high at 0.96 and 0.92. Conclusion: Plasma miR-451 and miR-486 could be useful blood-based biomarkers for screening GC. PMID:22262318

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joung, M.; Woo, M. H.; Jeong, J. H.

For a high-performance, advanced tokamak mode in KSTAR, we have been developing a real-time control system of MHD modes such as sawtooth and Neo-classical Tearing Mode (NTM) by ECH/ECCD. The active feedback control loop will be also added to the mirror position and the real-time detection of the mode position. In this year, for the stabilization of NTM that is crucial to plasma performance we have implemented open-loop ECH antenna control system in KSTAR Plasma Control System (PCS) for ECH mirror movement during a single plasma discharge. KSTAR 170 GHz ECH launcher which was designed and fabricated by collaboration withmore » PPPL and POSTECH has a final mirror of a poloidally and toroidally steerable mirror. The poloidal steering motion is only controlled in the real-time NTM control system and its maximum steering speed is 10 degree/sec by DC motor. However, the latency of the mirror control system and the return period of ECH antenna mirror angle are not fast because the existing launcher mirror control system is based on PLC which is connected to the KSTAR machine network through serial to LAN converter. In this paper, we present the design of real time NTM control system, ECH requirements, and the upgrade plan.« less

Performance Assessment of Model-Based Optimal Feedforward and Feedback Current Profile Control in NSTX-U using the TRANSP Code

NASA Astrophysics Data System (ADS)

Ilhan, Z.; Wehner, W. P.; Schuster, E.; Boyer, M. D.; Gates, D. A.; Gerhardt, S.; Menard, J.

2015-11-01

Active control of the toroidal current density profile is crucial to achieve and maintain high-performance, MHD-stable plasma operation in NSTX-U. A first-principles-driven, control-oriented model describing the temporal evolution of the current profile has been proposed earlier by combining the magnetic diffusion equation with empirical correlations obtained at NSTX-U for the electron density, electron temperature, and non-inductive current drives. A feedforward + feedback control scheme for the requlation of the current profile is constructed by embedding the proposed nonlinear, physics-based model into the control design process. Firstly, nonlinear optimization techniques are used to design feedforward actuator trajectories that steer the plasma to a desired operating state with the objective of supporting the traditional trial-and-error experimental process of advanced scenario planning. Secondly, a feedback control algorithm to track a desired current profile evolution is developed with the goal of adding robustness to the overall control scheme. The effectiveness of the combined feedforward + feedback control algorithm for current profile regulation is tested in predictive simulations carried out in TRANSP. Supported by PPPL.

Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability.

PubMed

Yang, Seung Yun; Kim, Eung-Sam; Jeon, Gumhye; Choi, Kwan Yong; Kim, Jin Kon

2013-04-01

We independently controlled surface topography and wettability of polystyrene (PS) films by CF4 and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF4 plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ~11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Copyright © 2012 Elsevier B.V. All rights reserved.

Evolution of plasma wakes in density up- and down-ramps

NASA Astrophysics Data System (ADS)

Zhang, C. J.; Joshi, C.; Xu, X. L.; Mori, W. B.; Li, F.; Wan, Y.; Hua, J. F.; Pai, C. H.; Wang, J.; Lu, W.

2018-02-01

The time evolution of plasma wakes in density up- and down-ramps is examined through theory and particle-in-cell simulations. Motivated by observation of the reversal of a linear plasma wake in a plasma density upramp in a recent experiment (Zhang et al 2017 Phys. Rev. Lett. 119 064801) we have examined the behaviour of wakes in plasma ramps that always accompany any plasma source used for plasma-based acceleration. In the up-ramp case it is found that, after the passage of the drive pulse, the wavnumber/wavelength of the wake starts to decrease/increase with time until it eventually tends to zero/infinity, then the wake reverses its propagation direction and the wavenunber/wavelength of the wake begins to increase/shrink. The evolutions of the wavenumber and the phase velocity of the wake as functions of time are shown to be significantly different in the up-ramp and the down-ramp cases. In the latter case the wavenumber of the wake at a particular position in the ramp increases until the wake is eventually damped. It is also shown that the waveform of the wake at a particular time after being excited can be precisely controlled by tuning the initial plasma density profile, which may enable a new type of plasma-based ultrafast optics.

Layer-controllable graphene by plasma thinning and post-annealing

NASA Astrophysics Data System (ADS)

Zhang, Lufang; Feng, Shaopeng; Xiao, Shaoqing; Shen, Gang; Zhang, Xiumei; Nan, Haiyan; Gu, Xiaofeng; Ostrikov, Kostya (Ken)

2018-05-01

The electronic structure of graphene depends crucially on its layer number and therefore engineering the number of graphene's atomic stacking layers is of great importance for the preparation of graphene-based devices. In this paper, we demonstrated a relatively less invasive, high-throughput and uniform large-area plasma thinning of graphene based on direct bombardment effect of fast-moving ionic hydrogen or argon species. Any desired number of graphene layers including trilayer, bilayer and monolayer can be obtained. Structural changes of graphene layers are studied by optical microscopy, Raman spectroscopy and atomic force microscopy. Post annealing is adopted to self-heal the lattice defects induced by the ion bombardment effect. This plasma etching technique is efficient and compatible with semiconductor manufacturing processes, and may find important applications for graphene-based device fabrication.

Platelet morphology and plasma indices of platelet activation in essential hypertension: effects of amlodipine-based antihypertensive therapy.

PubMed

Nadar, Sunil; Blann, Andrew D; Lip, Gregory Y H

2004-01-01

Platelet abnormalities have been described in hypertension, especially in the presence of target organ damage. Our aim was to study the differences in morphology and indices of platelet activation in treatment-naive patients with essential hypertension as compared to normotensive controls and secondly, to study the effects of amlodipine-based antihypertensive therapy on these indices. We recruited 42 previously untreated, newly diagnosed hypertensive patients (25 men; mean age 53 years) for the cross-sectional study, where data were compared with those from 30 normotensive controls (20 men; mean age 57 years). Of the 42 untreated hypertensive patients who were recruited, 27 patients successfully completed, the six-month treatment phase with amlodipine-based antihypertensive therapy. Platelet morphology (volume and mass) was quantified, and plasma markers of platelet activation (betaTG and sPsel) measured in citrated plasma. The mass of P-selectin in each platelet (pPsel) was determined by lysing a fixed number of platelets and then determining the levels of P-selectin in the lysate. Hypertensive patients had significantly higher platelet volume (P = 0.01) and mass (P = 0.003), plasma betaTG and sPsel, and pPsel levels (all P < 0.001) compared to the controls. After a mean treatment time of 6 months, there was a decrease in platelet volume (P < 0.001) and mass (P = 0.02), with lower pPsel, sPsel and BTG levels (all P < 0.001) compared to the untreated state. Treatment of uncomplicated essential hypertension using amlodipine-based anti-hypertensive therapy results in a reversal of the platelet morphology abnormalities and indices of platelet activation. This may contribute to a reduction in thrombosis-related complications seen in those whose blood pressure lowering is effective.

Study of Globus-M Tokamak Poloidal System and Plasma Position Control

NASA Astrophysics Data System (ADS)

Dokuka, V. N.; Korenev, P. S.; Mitrishkin, Yu. V.; Pavlova, E. A.; Patrov, M. I.; Khayrutdinov, R. R.

2017-12-01

In order to provide efficient performance of tokamaks with vertically elongated plasma position, control systems for limited and diverted plasma configuration are required. The accuracy, stability, speed of response, and reliability of plasma position control as well as plasma shape and current control depend on the performance of the control system. Therefore, the problem of the development of such systems is an important and actual task in modern tokamaks. In this study, the measured signals from the magnetic loops and Rogowski coils are used to reconstruct the plasma equilibrium, for which linear models in small deviations are constructed. We apply methods of the H∞-optimization theory to the synthesize control system for vertical and horizontal position of plasma capable to working with structural uncertainty of the models of the plant. These systems are applied to the plasma-physical DINA code which is configured for the tokamak Globus-M plasma. The testing of the developed systems applied to the DINA code with Heaviside step functions have revealed the complex dynamics of plasma magnetic configurations. Being close to the bifurcation point in the parameter space of unstable plasma has made it possible to detect an abrupt change in the X-point position from the top to the bottom and vice versa. Development of the methods for reconstruction of plasma magnetic configurations and experience in designing plasma control systems with feedback for tokamaks provided an opportunity to synthesize new digital controllers for plasma vertical and horizontal position stabilization. It also allowed us to test the synthesized digital controllers in the closed loop of the control system with the DINA code as a nonlinear model of plasma.

Sharp plasma pinnacle structure based on shockwave for an improved laser wakefield accelerator

NASA Astrophysics Data System (ADS)

Fang, Ming; Zhang, Zhijun; Wang, Wentao; Liu, Jiansheng; Li, Ruxin

2018-07-01

We created a sharp plasma pinnacle structure for localized electron injection and controlled acceleration in a laser wakefield accelerator. The formation of this shockwave-based pinnacle structure was investigated using aerodynamic theory. Details and scaling laws for the shockwave angle, shock position, shock width, and density ratio were experimentally and theoretically presented. Such work is crucial to yielding an expected plasma density distribution in a laser–plasma experiment but has had little discussion in the literature. Compared with the commonly used shock downramp structure, the particle-in-cell simulations demonstrated that the e beam injected in the created pinnacle structure could be accelerated to higher energy with much smaller root-mean-square relative energy spread. Moreover, this study indicated that the beam charge and transverse emittance can be tuned by the shock angle.

Plasma-based actuators for turbulent boundary layer control in transonic flow

NASA Astrophysics Data System (ADS)

Budovsky, A. D.; Polivanov, P. A.; Vishnyakov, O. I.; Sidorenko, A. A.

2017-10-01

The study is devoted to development of methods for active control of flow structure typical for the aircraft wings in transonic flow with turbulent boundary layer. The control strategy accepted in the study was based on using of the effects of plasma discharges interaction with miniature geometrical obstacles of various shapes. The conceptions were studied computationally using 3D RANS, URANS approaches. The results of the computations have shown that energy deposition can significantly change the flow pattern over the obstacles increasing their influence on the flow in boundary layer region. Namely, one of the most interesting and promising data were obtained for actuators basing on combination of vertical wedge with asymmetrical plasma discharge. The wedge considered is aligned with the local streamlines and protruding in the flow by 0.4-0.8 of local boundary layer thickness. The actuator produces negligible distortion of the flow at the absence of energy deposition. Energy deposition along the one side of the wedge results in longitudinal vortex formation in the wake of the actuator providing momentum exchange in the boundary layer. The actuator was manufactured and tested in wind tunnel experiments at Mach number 1.5 using the model of flat plate. The experimental data obtained by PIV proved the availability of the actuator.

Study on factors affecting the droplet temperature in plasma MIG welding process

NASA Astrophysics Data System (ADS)

Mamat, Sarizam Bin; Tashiro, Shinichi; Tanaka, Manabu; Yusoff, Mahani

2018-04-01

In the present study, the mechanism to control droplet temperature in the plasma MIG welding was discussed based on the measurements of the droplet temperature for a wide range of MIG currents with different plasma electrode diameters. The measurements of the droplet temperatures were conducted using a two color temperature measurement method. The droplet temperatures in the plasma MIG welding were then compared with those in the conventional MIG welding. As a result, the droplet temperature in the plasma MIG welding was found to be reduced in comparison with the conventional MIG welding under the same MIG current. Especially when the small plasma electrode diameter was used, the decrease in the droplet temperature reached maximally 500 K. Also, for a particular WFS, the droplet temperatures in the plasma MIG welding were lower than those in the conventional MIG welding. It is suggested that the use of plasma contributes to reducing the local heat input into the base metal by the droplet. The presence of the plasma surrounding the wire is considered to increase the electron density in its vicinity, resulting in the arc attachment expanding upwards along the wire surface to disperse the MIG current. This dispersion of MIG current causes a decrease in current density on the droplet surface, lowering the droplet temperature. Furthermore, dispersed MIG current also weakens the electromagnetic pinch force acting on the neck of the wire above the droplet. This leads to a larger droplet diameter with increased surface area through lower frequency of droplet detachment to decrease the MIG current density on the droplet surface, as compared to the conventional MIG welding at the same MIG current. Thus, the lower droplet temperature is caused by the reduction of heat flux into the droplet. Consequently, the mechanism to control droplet temperature in the plasma MIG welding was clarified.

(1)H-Nuclear magnetic resonance-based plasma metabolic profiling of dairy cows with clinical and subclinical ketosis.

PubMed

Sun, L W; Zhang, H Y; Wu, L; Shu, S; Xia, C; Xu, C; Zheng, J S

2014-03-01

The purpose of this study was to assess the metabolic profile of plasma samples from cows with clinical and subclinical ketosis. According to clinical signs and 3-hydroxybutyrate plasma levels, 81 multiparous Holstein cows were selected from a dairy farm 7 to 21 d after calving. The cows were divided into 3 groups: cows with clinical ketosis, cows with subclinical ketosis, and healthy control cows. (1)H-Nuclear magnetic resonance-based metabolomics was used to assess the plasma metabolic profiles of the 3 groups. The data were analyzed by principal component analysis, partial least squares discriminant analysis, and orthogonal partial least-squares discriminant analysis. The differences in metabolites among the 3 groups were assessed. The orthogonal partial least-squares discriminant analysis model differentiated the 3 groups of plasma samples. The model predicted clinical ketosis with a sensitivity of 100% and a specificity of 100%. In the case of subclinical ketosis, the model had a sensitivity of 97.0% and specificity of 95.7%. Twenty-five metabolites, including acetoacetate, acetone, lactate, glucose, choline, glutamic acid, and glutamine, were different among the 3 groups. Among the 25 metabolites, 4 were upregulated, 7 were downregulated, and 14 were both upregulated and downregulated. The results indicated that plasma (1)H-nuclear magnetic resonance-based metabolomics, coupled with pattern recognition analytical methods, not only has the sensitivity and specificity to distinguish cows with clinical and subclinical ketosis from healthy controls, but also has the potential to be developed into a clinically useful diagnostic tool that could contribute to a further understanding of the disease mechanisms. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A Sub-microsecond Pulsed Plasma Jet for Endodontic Biofilm Disinfection

NASA Astrophysics Data System (ADS)

Jiang, Chunqi; Schaudinn, Christoph; Jaramillo, David E.; Gundersen, Martin A.; Costerton, J. William

A pulsed, tapered cylindrical plasma jet, several centimeter long and <2 mm in diameter, has been generated by a concentric tubular device for root canal disinfection. This plasma dental probe is typically powered with ˜100 ns, 1 kHz, multi-kilovolt electric pulses and filled with 5 SLPM (standard liter per minute) He/(1%)O2 flow. We report here an in vitro study of the antimicrobial effect of the room temperature plasma jet against monolayer Enterococcus faecalis biofilms on bovine dentins. Resultant colony-forming unit counts were associated with changes in bacterial cell morphology observed using scanning electron microscopy (SEM) following the treatment and control. Treatment of dentin discs cultivated with E. faecalis monolayer biofilms with the plasma (average power ≈ 1 W) for 5 min resulted in 92.4% kill (P < 0.0001). Severe disruption of the cell membranes was observed for the plasma treatment group, while the morphology of the cells remained intact for the negative control group. In addition, a pilot ex vivo test was conducted to examine the bactericidal effect of the plasma against saliva-derived biofilms cultivated in human root canals. Conspicuous biofilm disruption and cleared dentinal surfaces were observed in the canal after the plasma treatment for 5 min. We ­conclude that this non-thermal pulsed plasma-based technology is a potential ­alternative or supplement to existing protocols for root canal disinfection.

ELM control with RMP: plasma response models and the role of edge peeling response

NASA Astrophysics Data System (ADS)

Liu, Yueqiang; Ham, C. J.; Kirk, A.; Li, Li; Loarte, A.; Ryan, D. A.; Sun, Youwen; Suttrop, W.; Yang, Xu; Zhou, Lina

2016-11-01

Resonant magnetic perturbations (RMP) have extensively been demonstrated as a plausible technique for mitigating or suppressing large edge localized modes (ELMs). Associated with this is a substantial amount of theory and modelling efforts during recent years. Various models describing the plasma response to the RMP fields have been proposed in the literature, and are briefly reviewed in this work. Despite their simplicity, linear response models can provide alternative criteria, than the vacuum field based criteria, for guiding the choice of the coil configurations to achieve the best control of ELMs. The role of the edge peeling response to the RMP fields is illustrated as a key indicator for the ELM mitigation in low collisionality plasmas, in various tokamak devices.

Abnormal plasma DNA profiles in early ovarian cancer using a non-invasive prenatal testing platform: implications for cancer screening.

PubMed

Cohen, Paul A; Flowers, Nicola; Tong, Stephen; Hannan, Natalie; Pertile, Mark D; Hui, Lisa

2016-08-24

Non-invasive prenatal testing (NIPT) identifies fetal aneuploidy by sequencing cell-free DNA in the maternal plasma. Pre-symptomatic maternal malignancies have been incidentally detected during NIPT based on abnormal genomic profiles. This low coverage sequencing approach could have potential for ovarian cancer screening in the non-pregnant population. Our objective was to investigate whether plasma DNA sequencing with a clinical whole genome NIPT platform can detect early- and late-stage high-grade serous ovarian carcinomas (HGSOC). This is a case control study of prospectively-collected biobank samples comprising preoperative plasma from 32 women with HGSOC (16 'early cancer' (FIGO I-II) and 16 'advanced cancer' (FIGO III-IV)) and 32 benign controls. Plasma DNA from cases and controls were sequenced using a commercial NIPT platform and chromosome dosage measured. Sequencing data were blindly analyzed with two methods: (1) Subchromosomal changes were called using an open source algorithm WISECONDOR (WIthin-SamplE COpy Number aberration DetectOR). Genomic gains or losses ≥ 15 Mb were prespecified as "screen positive" calls, and mapped to recurrent copy number variations reported in an ovarian cancer genome atlas. (2) Selected whole chromosome gains or losses were reported using the routine NIPT pipeline for fetal aneuploidy. We detected 13/32 cancer cases using the subchromosomal analysis (sensitivity 40.6 %, 95 % CI, 23.7-59.4 %), including 6/16 early and 7/16 advanced HGSOC cases. Two of 32 benign controls had subchromosomal gains ≥ 15 Mb (specificity 93.8 %, 95 % CI, 79.2-99.2 %). Twelve of the 13 true positive cancer cases exhibited specific recurrent changes reported in HGSOC tumors. The NIPT pipeline resulted in one "monosomy 18" call from the cancer group, and two "monosomy X" calls in the controls. Low coverage plasma DNA sequencing used for prenatal testing detected 40.6 % of all HGSOC, including 38 % of early stage cases. Our findings demonstrate the potential of a high throughput sequencing platform to screen for early HGSOC in plasma based on characteristic multiple segmental chromosome gains and losses. The performance of this approach may be further improved by refining bioinformatics algorithms and targeting selected cancer copy number variations.

Effect of high-dose phytase and citric acid, alone or in combination, on growth performance of broilers given diets severely limited in available phosphorus.

PubMed

Taheri, H R; Jabbari, Z; Adibnia, S; Shahir, M H; Hosseini, S A

2015-01-01

1. Two trials were conducted to evaluate the effect of high-dose phytase alone or in combination with citric acid (CA) in the diet severely limited in available phosphorus (P) on performance, plasma P and plasma Ca of broilers from 22 to 42 d of age. 2. In Trial 1, 297 21-d-old female chicks were placed into 27 pens and allocated to 9 maize-soybean meal-based dietary treatments, which were a positive control [PC, 4.23 g/kg non-phytate P (NPP)] and 8 negative control (NC, 1.35 g/kg NPP) groups consisting of two concentrations of CA (0 and 20 g/kg) and 4 concentrations of phytase (0, 1000, 2000 and 4000 U/kg) in a 2 × 4 factorial arrangement. In Trial 2, 192 21-d-old male chicks were placed into 24 pens and allocated to 6 wheat-canola meal-based dietary treatments, which were a PC (4.2 g/kg NPP), a NC (1.68 g/kg NPP) and 4 NC groups consisting of two concentrations of CA (0 and 20 g/kg) and two concentrations of phytase (2000 and 4000 U/kg) in a 2 × 2 factorial arrangement. 3. In both trials, birds fed on the PC had significantly higher average daily gain (ADG), average daily feed intake (ADFI), plasma P and lower feed conversion ratio (FCR) and plasma Ca than those of birds fed on the NC. CA supplementation significantly increased ADG and ADFI. There was a significant interaction between CA and phytase on plasma P where CA improved the effect of phytase on plasma P. In Trial 1, phytase addition improved ADG, ADFI, FCR and plasma Ca linearly. 4. Briefly, this research showed the interaction effect between CA and phytase on plasma P when broilers were fed on diets based on maize-soybean meal or wheat-canola meal. The results showed that CA supplementation lowered the concentration of phytase that is needed in low NPP diets to increase plasma P.

Related factors to disparity of diabetes care in Iran.

PubMed

Mirzazadeh, Ali; Baradaran, Hamid R; Haghdoost, Ali A; Salari, Pooria

2009-05-01

We determined, in Iranian patients with diabetes mellitus, the prevalence of inadequate glycemic control and its predictors. The data from a national population-based survey that included a random sample of 89 404 Iranian individuals in 2005 were analyzed. In that sample, 2923 diabetic subjects (age range, 25-64 years) were identified. We linked the results of their fasting plasma glucose levels with demographic and behavioral variables to determine predictors of poor glycemic control. About 57% of the subjects had a fasting plasma glucose level of > or =130 mg/dL. That percentage was comparable in male and female subjects and in literate and illiterate subjects. However, inhabitants in rural areas controlled their fasting plasma glucose level about 11% better than did subjects who lived in an urban area. We also found that control of the fasting plasma glucose level was much better in relatively younger diabetic patients. Diabetic subjects with a family history of type 2 diabetes mellitus exhibited a higher uncontrolled fasting plasma glucose level than those without positive family history of diabetes. The percentage of uncontrolled type 2 diabetes found in our study suggests that the Iranian healthcare system should devote more attention to that disorder, particularly in elderly individuals, who are more vulnerable to the complications of diabetes and control their disorder less well than do younger diabetic patients. The recent integration of diabetic care in primary healthcare systems in Iranian rural areas was found to have a promising effect on community health.

Error field optimization in DIII-D using extremum seeking control

DOE PAGES

Lanctot, M. J.; Olofsson, K. E. J.; Capella, M.; ...

2016-06-03

A closed-loop error field control algorithm is implemented in the Plasma Control System of the DIII-D tokamak and used to identify optimal control currents during a single plasma discharge. The algorithm, based on established extremum seeking control theory, exploits the link in tokamaks between maximizing the toroidal angular momentum and minimizing deleterious non-axisymmetric magnetic fields. Slowly-rotating n = 1 fields (the dither), generated by external coils, are used to perturb the angular momentum, monitored in real-time using a charge-exchange spectroscopy diagnostic. Simple signal processing of the rotation measurements extracts information about the rotation gradient with respect to the control coilmore » currents. This information is used to converge the control coil currents to a point that maximizes the toroidal angular momentum. The technique is well-suited for multi-coil, multi-harmonic error field optimizations in disruption sensitive devices as it does not require triggering locked tearing modes or plasma current disruptions. Control simulations highlight the importance of the initial search direction on the rate of the convergence, and identify future algorithm upgrades that may allow more rapid convergence that projects to convergence times in ITER on the order of tens of seconds.« less

Synthesis of Silicon Nanoparticles in Inductively Coupled Plasmas

NASA Astrophysics Data System (ADS)

Markosyan, Aram H.; Le Picard, Romain; Girshick, Steven L.; Kushner, Mark J.

2016-09-01

The synthesis of silicon nanoparticles (Si-NPs) is being investigated for their use in photo-emitting electronics, photovoltaics, and biotechnology. The ability to control the size and mono-disperse nature of Si-NPs is important to optimizing these applications. In this paper we discuss results from a computational investigation of Si-NP formation and growth in an inductively coupled plasma (ICP) reactor with the goal of achieving this control. We use a two dimensional numerical model where the algorithms for the kinetics of NP formation are self-consistently coupled with a plasma hydrodynamics simulation. The reactor modeled here resembles a GEC reference cell through which, for the base case, a mixture of Ar/SiH4 = 70/30 flows at 150 sccm at a pressure of 100 mTorr. In continuous wave mode, three coils located on top of the reactor deliver 150 W. The electric plasma potential confines negatively charged particles at the center of the discharge, increasing the residence time of negative NPs, which enables the NPs to potentially grow to large and controllable sizes of many to 100s nm. We discuss methods of controlling NP growth rates by varying the mole fraction and flow rate of SiH4, and using a pulsed plasma by varying the pulse period and duty cycle. Work supported by DOE Office of Fusion Energy Science and National Science Foundation.

Radiative cooling efficiencies and predicted spectra of species of the Io plasma torus

NASA Technical Reports Server (NTRS)

Shemansky, D. E.

1980-01-01

Calculations of the physical condition of the Io plasma torus have been made based on the recent Voyager EUV observations. The calculations represent an assumed thin plasma collisional ionization equilibrium among the states within each species. The observations of the torus are all consistent with this condition. The major energy loss mechanism is radiative cooling in discrete transitions. Calculations of radiative cooling efficiencies of the identified species leads to an estimated energy loss rate of at least 1.5 x 10 to the 12th watts. The mean electron temperature and density of the plasma are estimated to be 100,000 K and 2100/cu cm. The estimated number densities of S III, S IV, and O III are roughly 95, 80, and 190-740/cu cm. Upper limits have been placed on a number of other species based on the first published Voyager EUV spectrum of the torus. The assumption that energy is supplied to the torus through injection of neutral particles from Io leads to the conclusion that ion loss rates are controlled by diffusion, and relative species abundances consequently are not controlled by collisional ionization equilibrium.

ATCA digital controller hardware for vertical stabilization of plasmas in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Batista, A. J. N.; Sousa, J.; Varandas, C. A. F.

2006-10-15

The efficient vertical stabilization (VS) of plasmas in tokamaks requires a fast reaction of the VS controller, for example, after detection of edge localized modes (ELM). For controlling the effects of very large ELMs a new digital control hardware, based on the Advanced Telecommunications Computing Architecture trade mark sign (ATCA), is being developed aiming to reduce the VS digital control loop cycle (down to an optimal value of 10 {mu}s) and improve the algorithm performance. The system has 1 ATCA trade mark sign processor module and up to 12 ATCA trade mark sign control modules, each one with 32 analogmore » input channels (12 bit resolution), 4 analog output channels (12 bit resolution), and 8 digital input/output channels. The Aurora trade mark sign and PCI Express trade mark sign communication protocols will be used for data transport, between modules, with expected latencies below 2 {mu}s. Control algorithms are implemented on a ix86 based processor with 6 Gflops and on field programmable gate arrays with 80 GMACS, interconnected by serial gigabit links in a full mesh topology.« less

Numerical studies of wall–plasma interactions and ionization phenomena in an ablative pulsed plasma thruster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Lei; School of Astronautics, Beihang University, Beijing 100191; Zeng, Guangshang

2016-07-15

Wall–plasma interactions excited by ablation controlled arcs are very critical physical processes in pulsed plasma thrusters (PPTs). Their effects on the ionization processes of ablated vapor into discharge plasma directly determine PPT performances. To reveal the physics governing the ionization phenomena in PPT discharge, a modified model taking into account the pyrolysis effect of heated polytetrafluoroethylene propellant on the wall–plasma interactions was developed. The feasibility of the modified model was analyzed by creating a one-dimensional simulation of a rectangular ablative PPT. The wall–plasma interaction results based on this modified model were found to be more realistic than for the unmodifiedmore » model; this reflects the dynamic changes of the inflow parameters during discharge in our model. Furthermore, the temporal and spatial variations of the different plasma species in the discharge chamber were numerically studied. The numerical studies showed that polytetrafluoroethylene plasma was mainly composed of monovalent ions; carbon and fluorine ions were concentrated in the upstream and downstream discharge chamber, respectively. The results based on this modified model were in good agreement with the experimental formation times of the various plasma species. A large number of short-lived and highly ionized carbon and fluorine species (divalent and trivalent ions) were created during initial discharge. These highly ionized species reached their peak density earlier than the singly ionized species.« less

Vortex formation in a complex plasma

NASA Astrophysics Data System (ADS)

Ishihara, Osamu

Complex plasma experiments in ground-based laboratories as well as in microgravity conditions have shown the formation of vortex structures in various conditions (e.g., 1,2,3,4). The vortex structures formed in a complex plasma are visible by naked eyes with the help of irradiating laser and the individual dust particles in the structure give us the opportunity to study detailed physics of the commonly observed natural phenomena known such as tornadoes, typhoons, hurricanes and dust devils. Based on the Navier-Stokes equation with proper complex plasma conditions we analyze as much as possible in a universal way the vortex structure and clarifies the role of the controlling parameters like flow velocity and external magnetic field. 1. G. E. Morfill,H. M. Thomas, U. Konopka,H. Rothermel, M. Zuzic, A. Ivlev, and J. Goree, Phys,. Rev. Lett. 83, 1598 (1999). 2. E. Nebbat and R. Annou, Phys. Plasmas 17, 093702 (2010). 3. Y. Saitou and O. Ishihara, Phys. Rev. Lett. 111, 185003 (2013). 4. V. N. Tsytovich and N. G. Gusein-zade, Plasma Phys. Rep. 39, 515 (2013).

Global- and renal-specific sympathoinhibition in aldosterone hypertension.

PubMed

Lohmeier, Thomas E; Liu, Boshen; Hildebrandt, Drew A; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

2015-06-01

Recent technology for chronic electric activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12 μg/kg per day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ≈40% and arterial pressure by 16±2 mm Hg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mm Hg) was diminished (≈55%) during aldosterone hypertension when compared with control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. © 2015 American Heart Association, Inc.

Global and Renal-Specific Sympathoinhibition in Aldosterone Hypertension

PubMed Central

Lohmeier, Thomas E.; Liu, Boshen; Hildebrandt, Drew A.; Cates, Adam W.; Georgakopoulos, Dimitrios; Irwin, Eric D.

2015-01-01

Recent technology for chronic electrical activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12µg/kg/day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ~ 40% and arterial pressure by 16±2 mmHg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mmHg) was diminished (~ 55%) during aldosterone hypertension as compared to control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. PMID:25895584

Circulating Plasma Levels of MicroRNA-21 and MicroRNA-221 Are Potential Diagnostic Markers for Primary Intrahepatic Cholangiocarcinoma

PubMed Central

Kemeny, Nancy; Kingham, T. Peter; Allen, Peter J.; D’Angelica, Michael I.; DeMatteo, Ronald P.; Betel, Doron; Klimstra, David; Jarnagin, William R.; Ventura, Andrea

2016-01-01

Background MicroRNAs (miRNAs) are potential biomarkers in various malignancies. We aim to characterize miRNA expression in intrahepatic cholangiocarcinoma (ICC) and identify circulating plasma miRNAs with potential diagnostic and prognostic utility. Methods Using deep-sequencing techniques, miRNA expression between tumor samples and non-neoplastic liver parenchyma were compared. Overexpressed miRNAs were measured in plasma from an independent cohort of patients with cholangiocarcinoma using RT-qPCR and compared with that healthy volunteers. The discriminatory ability of the evaluated plasma miRNAs between patients and controls was evaluated with receiving operating characteristic (ROC) curves. Results Small RNAs from 12 ICC and 11 tumor-free liver samples were evaluated. Unsupervised hierarchical clustering using the miRNA expression data showed clear grouping of ICC vs. non-neoplastic liver parenchyma. We identified 134 down-regulated and 128 upregulated miRNAs. Based on overexpression and high fold-change, miR21, miR200b, miR221, and miR34c were measured in plasma from an independent cohort of patients with ICC (n = 25) and healthy controls (n = 7). Significant overexpression of miR-21 and miR-221 was found in plasma from ICC patients. Furthermore, circulating miR-21 demonstrated a high discriminatory ability between patients with ICC and healthy controls (AUC: 0.94). Conclusion Among the differentially expressed miRNAs in ICC, miR-21 and miR-221 are overexpressed and detectable in the circulation. Plasma expression levels of these miRNAs, particularly miR-21, accurately differentiates patients with ICC from healthy controls and could potentially serve as adjuncts in diagnosis. Prospective validation and comparison with other hepatobiliary malignancies is required to establish their potential role as diagnostic and prognostic biomarkers. PMID:27685844

Dendritic cell immunotherapy followed by cART interruption during HIV-1 infection induces plasma protein markers of cellular immunity and neutrophil recruitment

PubMed Central

Cooper, Jason D.; Tomasik, Jakub; Bahn, Sabine; Aerts, Joeri L.; Osterhaus, Albert D. M. E.; Gruters, Rob A.; Andeweg, Arno C.

2018-01-01

Objectives To characterize the host response to dendritic cell-based immunotherapy and subsequent combined antiretroviral therapy (cART) interruption in HIV-1-infected individuals at the plasma protein level. Design An autologous dendritic cell (DC) therapeutic vaccine was administered to HIV-infected individuals, stable on cART. The effect of vaccination was evaluated at the plasma protein level during the period preceding cART interruption, during analytical therapy interruption and at viral reactivation. Healthy controls and post-exposure prophylactically treated healthy individuals were included as controls. Methods Plasma marker (‘analyte’) levels including cytokines, chemokines, growth factors, and hormones were measured in trial participants and control plasma samples using a multiplex immunoassay. Analyte levels were analysed using principle component analysis, cluster analysis and limma. Blood neutrophil counts were analysed using linear regression. Results Plasma analyte levels of HIV-infected individuals are markedly different from those of healthy controls and HIV-negative individuals receiving post-exposure prophylaxis. Viral reactivation following cART interruption also affects multiple analytes, but cART interruption itself only has only a minor effect. We find that Thyroxine-Binding Globulin (TBG) levels and late-stage neutrophil numbers correlate with the time off cART after DC vaccination. Furthermore, analysis shows that cART alters several regulators of blood glucose levels, including C-peptide, chromogranin-A and leptin. HIV reactivation is associated with the upregulation of CXCR3 ligands. Conclusions Chronic HIV infection leads to a change in multiple plasma analyte levels, as does virus reactivation after cART interruption. Furthermore, we find evidence for the involvement of TBG and neutrophils in the response to DC-vaccination in the setting of HIV-infection. PMID:29389978

Dendritic cell immunotherapy followed by cART interruption during HIV-1 infection induces plasma protein markers of cellular immunity and neutrophil recruitment.

PubMed

van den Ham, Henk-Jan; Cooper, Jason D; Tomasik, Jakub; Bahn, Sabine; Aerts, Joeri L; Osterhaus, Albert D M E; Gruters, Rob A; Andeweg, Arno C

2018-01-01

To characterize the host response to dendritic cell-based immunotherapy and subsequent combined antiretroviral therapy (cART) interruption in HIV-1-infected individuals at the plasma protein level. An autologous dendritic cell (DC) therapeutic vaccine was administered to HIV-infected individuals, stable on cART. The effect of vaccination was evaluated at the plasma protein level during the period preceding cART interruption, during analytical therapy interruption and at viral reactivation. Healthy controls and post-exposure prophylactically treated healthy individuals were included as controls. Plasma marker ('analyte') levels including cytokines, chemokines, growth factors, and hormones were measured in trial participants and control plasma samples using a multiplex immunoassay. Analyte levels were analysed using principle component analysis, cluster analysis and limma. Blood neutrophil counts were analysed using linear regression. Plasma analyte levels of HIV-infected individuals are markedly different from those of healthy controls and HIV-negative individuals receiving post-exposure prophylaxis. Viral reactivation following cART interruption also affects multiple analytes, but cART interruption itself only has only a minor effect. We find that Thyroxine-Binding Globulin (TBG) levels and late-stage neutrophil numbers correlate with the time off cART after DC vaccination. Furthermore, analysis shows that cART alters several regulators of blood glucose levels, including C-peptide, chromogranin-A and leptin. HIV reactivation is associated with the upregulation of CXCR3 ligands. Chronic HIV infection leads to a change in multiple plasma analyte levels, as does virus reactivation after cART interruption. Furthermore, we find evidence for the involvement of TBG and neutrophils in the response to DC-vaccination in the setting of HIV-infection.

Plasma metabolic changes in Chinese HIV-infected patients receiving lopinavir/ritonavir based treatment: Implications for HIV precision therapy.

PubMed

Li, Xiaolin; Wu, Tong; Jiang, Yongjun; Zhang, Zining; Han, Xiaoxu; Geng, Wenqing; Ding, Haibo; Kang, Jing; Wang, Qi; Shang, Hong

2018-05-16

The goal of this study is to profile the metabolic changes in the plasma of HIV patients receiving lopinavir/ritonavir (LPV/r)-based highly active antiretroviral therapy (HAART) relative to their treatment-naïve phase, aimed to identify precision therapy for HIV for improving prognosis and predicting dyslipidemia caused by LPV/r. 38 longitudinal plasma samples were collected from 19 HIV-infected patients both before and after antiretroviral therapy, and 18 samples from healthy individuals were used as controls. Untargeted metabolomics profiling of these plasma samples was performed using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). A total of 331 compounds of known identity were detected among these metabolites, a 67-metabolite signature mainly mapping to tryptophan, histidine, acyl carnitine, ketone bodies and fatty acid metabolism distinguished HIV patients from healthy controls. The levels of 19 out of the 67 altered metabolites including histidine, kynurenine, and 3-hydroxybutyrate (BHBA), recovered after LPV/r-based antiretroviral therapy, and histidine was positively correlated with the presence of CD4 + T lymphocytes. Furthermore, using receiver operating characteristic (ROC) analyses, we discovered that butyrylcarnitine in combination with myristic acid from plasma in treatment-naïve patients could predict dyslipidemia caused by LPV/r with 87% accuracy. Metabolites alterations in treatment-naïve HIV patients may indicate an inflammatory, oxidative state and mitochondrial dysfunction that is permissive for disease progression. Histidine may provide a specific protective function for HIV patients. Besides, elevated fatty acids levels including butyrylcarnitine and myristic acid after infection may indicate patients at risk of suffering from dyslipidemia after LPV/r-based HAART. Copyright © 2018 Elsevier Ltd. All rights reserved.

An arc control and protection system for the JET lower hybrid antenna based on an imaging system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Figueiredo, J., E-mail: joao.figueiredo@jet.efda.org; Mailloux, J.; Kirov, K.

Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is one of the additional heating systems at JET. It comprises 24 microwave generators (klystrons, operating at 3.7 GHz) providing up to 5 MW of heating and current drive to the JET plasma. This is done through an antenna composed of an array of waveguidesmore » facing the plasma. The protection system presented here is based primarily on an imaging arc detection and real time control system. It has adapted the ITER like wall hotspot protection system using an identical CCD camera and real time image processing unit. A filter has been installed to avoid saturation and spurious system triggers caused by ionization light. The antenna is divided in 24 Regions Of Interest (ROIs) each one corresponding to one klystron. If an arc precursor is detected in a ROI, power is reduced locally with subsequent potential damage and plasma disruption avoided. The power is subsequently reinstated if, during a defined interval of time, arcing is confirmed not to be present by image analysis. This system was successfully commissioned during the restart phase and beginning of the 2013 scientific campaign. Since its installation and commissioning, arcs and related phenomena have been prevented. In this contribution we briefly describe the camera, image processing, and real time control systems. Most importantly, we demonstrate that an LH antenna arc protection system based on CCD camera imaging systems works. Examples of both controlled and uncontrolled LH arc events and their consequences are shown.« less

Mild hypercholesterolemia, normal plasma triglycerides, and normal glucose levels across dementia staging in Alzheimer's disease: a clinical setting-based retrospective study.

PubMed

Ramdane, Said; Daoudi-Gueddah, Doria

2011-08-01

We examined retrospectively the concurrent relationships between fasting plasma total cholesterol, triglycerides, and glucose levels, and Alzheimer's disease (AD), in a clinical setting-based study. Total cholesterol level was higher in patients with AD compared to elderly controls; triglycerides or glucose levels did not significantly differ between the 2 groups. Respective plotted trajectories of change in cholesterol level across age were fairly parallel. No significant difference in total cholesterol levels was recorded between patients with AD classified by the Clinical Dementia Rating (CDR) score subgroups. These results suggest that patients with AD have relative mild total hypercholesterolemia, normal triglyceridemia, and normal fasting plasma glucose level. Mild total hypercholesterolemia seems to be permanent across age, and across dementia severity staging, and fairly parallels the trajectory of age-related change in total cholesterolemia of healthy controls. We speculate that these biochemical parameters pattern may be present long before-a decade at least-the symptomatic onset of the disease.

Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro

2012-02-15

In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them inmore » detail.« less

GPU-based optimal control for RWM feedback in tokamaks

DOE PAGES

Clement, Mitchell; Hanson, Jeremy; Bialek, Jim; ...

2017-08-23

The design and implementation of a Graphics Processing Unit (GPU) based Resistive Wall Mode (RWM) controller to perform feedback control on the RWM using Linear Quadratic Gaussian (LQG) control is reported herein. Also, the control algorithm is based on a simplified DIII-D VALEN model. By using NVIDIA’s GPUDirect RDMA framework, the digitizer and output module are able to write and read directly to and from GPU memory, eliminating memory transfers between host and GPU. In conclusion, the system and algorithm was able to reduce plasma response excited by externally applied fields by 32% during development experiments.

GPU-based optimal control for RWM feedback in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clement, Mitchell; Hanson, Jeremy; Bialek, Jim

The design and implementation of a Graphics Processing Unit (GPU) based Resistive Wall Mode (RWM) controller to perform feedback control on the RWM using Linear Quadratic Gaussian (LQG) control is reported herein. Also, the control algorithm is based on a simplified DIII-D VALEN model. By using NVIDIA’s GPUDirect RDMA framework, the digitizer and output module are able to write and read directly to and from GPU memory, eliminating memory transfers between host and GPU. In conclusion, the system and algorithm was able to reduce plasma response excited by externally applied fields by 32% during development experiments.

Control of External Kink Instability

NASA Astrophysics Data System (ADS)

Navratil, Gerald

2004-11-01

A fundamental pressure and current limiting phenomenon in magnetically confined plasmas for fusion energy is the long wavelength ideal-MHD kink mode. These modes have been extensively studied in tokamak and reversed field pinch (RFP) devices. They are characterized by significant amplitude on the boundary of the confined plasma and can therefore be controlled by manipulation of the external boundary conditions. In the past ten years, the theoretically predicted stabilizing effect of a nearby conducting wall has been documented in experiments, which opens the possibility of a significant increase in maximum stable plasma pressure. While these modes are predicted to remain unstable when the stabilizing wall is resistive, their growth rates are greatly reduced from the hydrodynamic time scale to the time scale of magnetic diffusion through the resistive wall. These resistive wall slowed kink modes have been identified as limiting phenomena in tokamak (DIII-D, PBX-M, HBT-EP, JT-60U, JET, NSTX) and RFP (HBTX, Extrap, T2R) devices. The theoretical prediction of stabilization to nearly the ideal wall pressure limit by toroidal plasma rotation and/or active feedback control using coils has recently been realized experimentally. Sustained, stable operation at double the no-wall pressure limit has been achieved. Discovery of the phenomenon of resonant field amplification by marginally stable kink modes and its role in the momentum balance of rotationally stabilized plasmas has emerged as a key feature. A theoretical framework, based on an extension of the very successful treatment of the n=0 axisymmetric mode developed in the early 1990's, to understand the stabilization mechanisms and model the performance of active feedback control systems is now established. This allows design of kink control systems for burning plasma experiments like ITER.

Insight into hydrogenation of graphene: Effect of hydrogen plasma chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felten, A.; Nittler, L.; Pireaux, J.-J.

2014-11-03

Plasma hydrogenation of graphene has been proposed as a tool to modify the properties of graphene. However, hydrogen plasma is a complex system and controlled hydrogenation of graphene suffers from a lack of understanding of the plasma chemistry. Here, we correlate the modifications induced on monolayer graphene studied by Raman spectroscopy with the hydrogen ions energy distributions obtained by mass spectrometry. We measure the energy distribution of H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +} ions for different plasma conditions showing that their energy strongly depends on the sample position, pressure, and plasma power and can reach values asmore » high as 45 eV. Based on these measurements, we speculate that under specific plasma parameters, protons should possess enough energy to penetrate the graphene sheet. Therefore, a graphene membrane could become, under certain conditions, transparent to both protons and electrons.« less

Large-scale inference of protein tissue origin in gram-positive sepsis plasma using quantitative targeted proteomics

PubMed Central

Malmström, Erik; Kilsgård, Ola; Hauri, Simon; Smeds, Emanuel; Herwald, Heiko; Malmström, Lars; Malmström, Johan

2016-01-01

The plasma proteome is highly dynamic and variable, composed of proteins derived from surrounding tissues and cells. To investigate the complex processes that control the composition of the plasma proteome, we developed a mass spectrometry-based proteomics strategy to infer the origin of proteins detected in murine plasma. The strategy relies on the construction of a comprehensive protein tissue atlas from cells and highly vascularized organs using shotgun mass spectrometry. The protein tissue atlas was transformed to a spectral library for highly reproducible quantification of tissue-specific proteins directly in plasma using SWATH-like data-independent mass spectrometry analysis. We show that the method can determine drastic changes of tissue-specific protein profiles in blood plasma from mouse animal models with sepsis. The strategy can be extended to several other species advancing our understanding of the complex processes that contribute to the plasma proteome dynamics. PMID:26732734

Numerical and experimental investigation of plasma plume deflection with MHD flow control

NASA Astrophysics Data System (ADS)

Kai, ZHAO; Feng, LI; Baigang, SUN; Hongyu, YANG; Tao, ZHOU; Ruizhi, SUN

2018-04-01

This paper presents a composite magneto hydrodynamics (MHD) method to control the low-temperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine. The principle of plasma flow with MHD control is analyzed. The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model. A test rig with plasma flow controlled by MHD is established. An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow. Finally, plasma plume deflection is obtained in different working conditions. The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation. A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K. The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity. It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.

Early Fluid and Protein Shifts in Men During Water Immersion

NASA Technical Reports Server (NTRS)

Hinghofer-Szalkay, H.; Harrison, M. H.; Greenleaf, J. E.

1987-01-01

High precision blood and plasma densitometry was used to measure transvascular fluid shifts during water immersion to the neck. Six men (28-49 years) undertook 30 min of standing immersion in water at 35.0 +/- 0.2 C; immersion was preceded by 30 min control standing in air at 28 +/- 1 C. Blood was sampled from an antecubital catheter for determination of Blood Density (BD), Plasma Density (PD), Haematocrit (Ht), total Plasma Protein Concentration (PPC), and Plasma Albumin Concentration (PAC). Compared to control, significant decreases (p less than 0.01) in all these measures were observed after 20 min immersion. At 30 min, plasma volume had increased by 11.0 +/- 2.8%; the average density of the fluid shifted from extravascular fluid into the vascular compartment was 1006.3 g/l; albumin moved with the fluid and its albumin concentration was about one-third of the plasma protein concentration during early immersion. These calculations are based on the assumption that the F-cell ratio remained unchanged. No changes in erythrocyte water content during immersion were found. Thus, immersion-induced haemodilution is probably accompanied by protein (mainly albumin) augmentation which accompanies the intra-vascular fluid shift.

Magnetic control of magnetohydrodynamic instabilities in tokamaks

DOE PAGES

Strait, Edward J.

2014-11-24

Externally applied, non-axisymmetric magnetic fields form the basis of several relatively simple and direct methods to control magnetohydrodynamic (MHD) instabilities in a tokamak, and most present and planned tokamaks now include a set of non-axisymmetric control coils for application of fields with low toroidal mode numbers. Non-axisymmetric applied fields are routinely used to compensate small asymmetries ( δB/B ~ 10 -3 to 10 -4) of the nominally axisymmetric field, which otherwise can lead to instabilities through braking of plasma rotation and through direct stimulus of tearing modes or kink modes. This compensation may be feedback-controlled, based on the magnetic responsemore » of the plasma to the external fields. Non-axisymmetric fields are used for direct magnetic stabilization of the resistive wall mode — a kink instability with a growth rate slow enough that feedback control is practical. Saturated magnetic islands are also manipulated directly with non-axisymmetric fields, in order to unlock them from the wall and spin them to aid stabilization, or position them for suppression by localized current drive. Several recent scientific advances form the foundation of these developments in the control of instabilities. Most fundamental is the understanding that stable kink modes play a crucial role in the coupling of non-axisymmetric fields to the plasma, determining which field configurations couple most strongly, how the coupling depends on plasma conditions, and whether external asymmetries are amplified by the plasma. A major advance for the physics of high-beta plasmas ( β = plasma pressure/magnetic field pressure) has been the understanding that drift-kinetic resonances can stabilize the resistive wall mode at pressures well above the ideal-MHD stability limit, but also that such discharges can be very sensitive to external asymmetries. The common physics of stable kink modes has brought significant unification to the topics of static error fields at low beta and resistive wall modes at high beta. Furthermore, these and other scientific advances, and their application to control of MHD instabilities, will be reviewed with emphasis on the most recent results and their applicability to ITER.« less

Mechanism for Plasma Etching of Shallow Trench Isolation Features in an Inductively Coupled Plasma

NASA Astrophysics Data System (ADS)

Agarwal, Ankur; Rauf, Shahid; He, Jim; Choi, Jinhan; Collins, Ken

2011-10-01

Plasma etching for microelectronics fabrication is facing extreme challenges as processes are developed for advanced technological nodes. As device sizes shrink, control of shallow trench isolation (STI) features become more important in both logic and memory devices. Halogen-based inductively coupled plasmas in a pressure range of 20-60 mTorr are typically used to etch STI features. The need for improved performance and shorter development cycles are placing greater emphasis on understanding the underlying mechanisms to meet process specifications. In this work, a surface mechanism for STI etch process will be discussed that couples a fundamental plasma model to experimental etch process measurements. This model utilizes ion/neutral fluxes and energy distributions calculated using the Hybrid Plasma Equipment Model. Experiments are for blanket Si wafers in a Cl2/HBr/O2/N2 plasma over a range of pressures, bias powers, and flow rates of feedstock gases. We found that kinetic treatment of electron transport was critical to achieve good agreement with experiments. The calibrated plasma model is then coupled to a string-based feature scale model to quantify the effect of varying process parameters on the etch profile. We found that the operating parameters strongly influence critical dimensions but have only a subtle impact on the etch depths.

The Auroral Particles experiment

NASA Technical Reports Server (NTRS)

1981-01-01

An instrument for the detection of particles in the energy range of 0.1 ev to 80 Kev was designed, built, tested, calibrated, and flown onboard the spacecraft ATS-6. Data from this instrument generated the following research: intensive studies of the plasma in the vicinity of the spacecraft; global variations of plasmas; correlative studies using either other spacecraft or ground based measurements; and studies of spacecraft interactions with ambient plasmas including charging, local electric fields due to differential charging, and active control of spacecraft potential. Results from this research are presented.

Preparation of red blood cell concentrates and plasma units from whole blood held overnight using a hollow-fibre separation system.

PubMed

Johnson, L; Kwok, M; Marks, D C

2015-02-01

The ErySep system represents an alternative to centrifuge-based whole blood (WB) separation, using gravity and filtration through hollow-fibres (0·2 µm pore size) to produce red blood cell (RBC) and plasma components. The aim of this study was to characterise the quality of ErySep RBC and plasma units compared with standard products from WB held overnight. Two ABO-compatible WB units (n = 24) were pooled and split to produce matched products. One of the WB units was separated into components using the ErySep system (ErySep; n = 12), whereas the other units were separated by centrifugation (control; n = 12). RBC units were stored at 2-6 °C and assessed for in vitro quality over 42 days of storage. Plasma was frozen at -30 °C and tested upon thawing. Processing WB with the ErySep system took longer than controls. The ErySep RBC units were of an appropriate volume (307 ± 17 mL) and contained sufficient Hb (50 ± 2 g unit(-1) ). ErySep RBC components contained more microparticles relative to controls at expiry. The plasma volume, total protein, coagulation factor activity (fibrinogen, FV, FVIII) and number of microparticles was lower in the ErySep units compared with controls. Following overnight hold of WB, the ErySep system was capable of producing RBC components that met specifications. However, the ErySep plasma components did not meet quality specifications. © 2015 British Blood Transfusion Society.

Real time MHD mode control using ECCD in KSTAR: Plan and requirements

NASA Astrophysics Data System (ADS)

Joung, M.; Woo, M. H.; Jeong, J. H.; Hahn, S. H.; Yun, S. W.; Lee, W. R.; Bae, Y. S.; Oh, Y. K.; Kwak, J. G.; Yang, H. L.; Namkung, W.; Park, H.; Cho, M. H.; Kim, M. H.; Kim, K. J.; Na, Y. S.; Hosea, J.; Ellis, R.

2014-02-01

For a high-performance, advanced tokamak mode in KSTAR, we have been developing a real-time control system of MHD modes such as sawtooth and Neo-classical Tearing Mode (NTM) by ECH/ECCD. The active feedback control loop will be also added to the mirror position and the real-time detection of the mode position. In this year, for the stabilization of NTM that is crucial to plasma performance we have implemented open-loop ECH antenna control system in KSTAR Plasma Control System (PCS) for ECH mirror movement during a single plasma discharge. KSTAR 170 GHz ECH launcher which was designed and fabricated by collaboration with PPPL and POSTECH has a final mirror of a poloidally and toroidally steerable mirror. The poloidal steering motion is only controlled in the real-time NTM control system and its maximum steering speed is 10 degree/sec by DC motor. However, the latency of the mirror control system and the return period of ECH antenna mirror angle are not fast because the existing launcher mirror control system is based on PLC which is connected to the KSTAR machine network through serial to LAN converter. In this paper, we present the design of real time NTM control system, ECH requirements, and the upgrade plan.

The significance and robustness of a plasma free amino acid (PFAA) profile-based multiplex function for detecting lung cancer

PubMed Central

2013-01-01

Background We have recently reported on the changes in plasma free amino acid (PFAA) profiles in lung cancer patients and the efficacy of a PFAA-based, multivariate discrimination index for the early detection of lung cancer. In this study, we aimed to verify the usefulness and robustness of PFAA profiling for detecting lung cancer using new test samples. Methods Plasma samples were collected from 171 lung cancer patients and 3849 controls without apparent cancer. PFAA levels were measured by high-performance liquid chromatography (HPLC)–electrospray ionization (ESI)–mass spectrometry (MS). Results High reproducibility was observed for both the change in the PFAA profiles in the lung cancer patients and the discriminating performance for lung cancer patients compared to previously reported results. Furthermore, multivariate discriminating functions obtained in previous studies clearly distinguished the lung cancer patients from the controls based on the area under the receiver-operator characteristics curve (AUC of ROC = 0.731 ~ 0.806), strongly suggesting the robustness of the methodology for clinical use. Moreover, the results suggested that the combinatorial use of this classifier and tumor markers improves the clinical performance of tumor markers. Conclusions These findings suggest that PFAA profiling, which involves a relatively simple plasma assay and imposes a low physical burden on subjects, has great potential for improving early detection of lung cancer. PMID:23409863

Plasma Equilibrium Control in Nuclear Fusion Devices 2. Plasma Control in Magnetic Confinement Devices 2.1 Plasma Control in Tokamaks

NASA Astrophysics Data System (ADS)

Fukuda, Takeshi

The plasma control technique for use in large tokamak devices has made great developmental strides in the last decade, concomitantly with progress in the understanding of tokamak physics and in part facilitated by the substantial advancement in the computing environment. Equilibrium control procedures have thereby been established, and it has been pervasively recognized in recent years that the real-time feedback control of physical quantities is indispensable for the improvement and sustainment of plasma performance in a quasi-steady-state. Further development is presently undertaken to realize the “advanced plasma control” concept, where integrated fusion performance is achieved by the simultaneous feedback control of multiple physical quantities, combined with equilibrium control.

RF generator interlock by plasma grid bias current - An alternate to Hα interlock

NASA Astrophysics Data System (ADS)

Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

2017-08-01

ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma operation, BC rises due to the presence of plasma electrons, almost in the same timescale as plasma light detection system and so, BC signal can also be used as RFG interlock. The BC signal transmission is through optical isolation to reduce noise interference with the signal. The response of the current monitoring signal available from the PG power supply of ROBIN is quite slow (in the order of few tens of milliseconds). Therefore, a fast response current detection electronic circuit having the ability to generate a PG current detection pulse with adjustable threshold set point has been developed and integrated with ROBIN, and the above concept has been demonstrated in ROBIN recently. The present paper will discuss this experimental activity and its results.

Characterization of X-ray emission from laser generated plasma

NASA Astrophysics Data System (ADS)

Cannavò, Antonino; Torrisi, Lorenzo; Ceccio, Giovanni; Cutroneo, Mariapompea; Calcagno, Lucia; Sciuto, Antonella; Mazzillo, Massimo

2018-01-01

X-ray emission from laser generated plasma was studied at low (1010 W/cm2) and high (1018 W/cm2) intensity using ns and fs laser, respectively. Plasma characteristics were controlled trough the laser parameters, the irradiation conditions and the target properties. The X-ray spectra were acquired using fast detection technique based on SiC diodes with different active regions. The X-ray yield increases with the atomic number of the target, both at low and high intensity, and a similar empirical law has been obtained. The X-ray emission mechanisms from plasma are correlated to the plasma temperature and density and to the Coulomb charge particle acceleration, due to the charge separation effects produced in the non-equilibrium plasma. Functional dependences, theoretical approaches and interpretation of possible mechanism will be presented and discussed.

Pulmonary administration of aerosolised fentanyl: pharmacokinetic analysis of systemic delivery

PubMed Central

Mather, Laurence E; Woodhouse, Annie; Ward, M Elizabeth; Farr, Stephen J; Rubsamen, Reid A; Eltherington, Lorne G

1998-01-01

Aims Pulmonary drug delivery is a promising noninvasive method of systemic administration. Our aim was to determine whether a novel breath-actuated, microprocessor-controlled metered dose oral inhaler (SmartMist™, Aradigm Corporation) could deliver fentanyl in a way suitable for control of severe pain. Methods Aersolised pulmonary fentanyl base 100–300 μg was administered to healthy volunteers using SmartMist™ and the resultant plasma concentration-time data were compared with those from the same doses administered by intravenous (i.v.) injection in the same subjects. Results Plasma concentrations from SmartMist™ were similar to those from i.v. injection. Time-averaged bioavailability based upon nominal doses averaged 100%, and was >50% within 5 min of delivery. Fentanyl systemic pharmacokinetics were similar to those previously reported with no trends to dose-dependence from either route. Side-effects (e.g. sedation, lightheadedness) were the same from both routes. Conclusions Fentanyl delivery using SmartMist™ can provide analgetically relevant plasma drug concentrations. This, combined with its ease of noninvasive use and transportability, suggests a strong potential for field and domicilliary use, and for patient controlled analgesia without the need for i.v. cannulae. PMID:9690947

Electro-mechanical probe positioning system for large volume plasma device

NASA Astrophysics Data System (ADS)

Sanyasi, A. K.; Sugandhi, R.; Srivastava, P. K.; Srivastav, Prabhakar; Awasthi, L. M.

2018-05-01

An automated electro-mechanical system for the positioning of plasma diagnostics has been designed and implemented in a Large Volume Plasma Device (LVPD). The system consists of 12 electro-mechanical assemblies, which are orchestrated using the Modbus communication protocol on 4-wire RS485 communications to meet the experimental requirements. Each assembly has a lead screw-based mechanical structure, Wilson feed-through-based vacuum interface, bipolar stepper motor, micro-controller-based stepper drive, and optical encoder for online positioning correction of probes. The novelty of the system lies in the orchestration of multiple drives on a single interface, fabrication and installation of the system for a large experimental device like the LVPD, in-house developed software, and adopted architectural practices. The paper discusses the design, description of hardware and software interfaces, and performance results in LVPD.

Real-time reflectometry measurement validation in H-mode regimes for plasma position control.

PubMed

Santos, J; Guimarais, L; Manso, M

2010-10-01

It has been shown that in H-mode regimes, reflectometry electron density profiles and an estimate for the density at the separatrix can be jointly used to track the separatrix within the precision required for plasma position control on ITER. We present a method to automatically remove, from the position estimation procedure, measurements performed during collapse and recovery phases of edge localized modes (ELMs). Based on the rejection mechanism, the method also produces an estimate confidence value to be fed to the position feedback controller. Preliminary results show that the method improves the real-time experimental separatrix tracking capabilities and has the potential to eliminate the need for an external online source of ELM event signaling during control feedback operation.

Fabrication of high-performance InGaZnOx thin film transistors based on control of oxidation using a low-temperature plasma

NASA Astrophysics Data System (ADS)

Takenaka, Kosuke; Endo, Masashi; Uchida, Giichiro; Setsuhara, Yuichi

2018-04-01

This work demonstrated the low-temperature control of the oxidation of Amorphous InGaZnOx (a-IGZO) films using inductively coupled plasma as a means of precisely tuning the properties of thin film transistors (TFTs) and as an alternative to post-deposition annealing at high temperatures. The effects of the plasma treatment of the as-deposited a-IGZO films were investigated by assessing the electrical properties of TFTs incorporating these films. A TFT fabricated using an a-IGZO film exposed to an Ar-H2-O2 plasma at substrate temperatures as low as 300 °C exhibited the best performance, with a field effect mobility as high as 42.2 cm2 V-1 s-1, a subthreshold gate voltage swing of 1.2 V decade-1, and a threshold voltage of 2.8 V. The improved transfer characteristics of TFTs fabricated with a-IGZO thin films treated using an Ar-H2-O2 plasma are attributed to the termination of oxygen vacancies around Ga and Zn atoms by OH radicals in the gas phase.

Inhibition of Crystal Growth during Plasma Enhanced Atomic Layer Deposition by Applying BIAS

PubMed Central

Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

2015-01-01

In this study, the influence of direct current (DC) biasing on the growth of titanium dioxide (TiO2) layers and their nucleation behavior has been investigated. Titania films were prepared by plasma enhanced atomic layer deposition (PEALD) using Ti(OiPr)4 as metal organic precursor. Oxygen plasma, provided by remote inductively coupled plasma, was used as an oxygen source. The TiO2 films were deposited with and without DC biasing. A strong dependence of the applied voltage on the formation of crystallites in the TiO2 layer is shown. These crystallites form spherical hillocks on the surface which causes high surface roughness. By applying a higher voltage than the plasma potential no hillock appears on the surface. Based on these results, it seems likely, that ions are responsible for the nucleation and hillock growth. Hence, the hillock formation can be controlled by controlling the ion energy and ion flux. The growth per cycle remains unchanged, whereas the refractive index slightly decreases in the absence of energetic oxygen ions. PMID:28793679

III International Conference on Laser and Plasma Researches and Technologies

NASA Astrophysics Data System (ADS)

2017-12-01

A.P. Kuznetsov and S.V. Genisaretskaya III Conference on Plasma and Laser Research and Technologies took place on January 24th until January 27th, 2017 at the National Research Nuclear University "MEPhI" (NRNU MEPhI). The Conference was organized by the Institute for Laser and Plasma Technologies and was supported by the Competitiveness Program of NRNU MEPhI. The conference program consisted of nine sections: • Laser physics and its application • Plasma physics and its application • Laser, plasma and radiation technologies in industry • Physics of extreme light fields • Controlled thermonuclear fusion • Modern problems of theoretical physics • Challenges in physics of solid state, functional materials and nanosystems • Particle accelerators and radiation technologies • Modern trends of quantum metrology. The conference is based on scientific fields as follows: • Laser, plasma and radiation technologies in industry, energetic, medicine; • Photonics, quantum metrology, optical information processing; • New functional materials, metamaterials, “smart” alloys and quantum systems; • Ultrahigh optical fields, high-power lasers, Mega Science facilities; • High-temperature plasma physics, environmentally-friendly energetic based on controlled thermonuclear fusion; • Spectroscopic synchrotron, neutron, laser research methods, quantum mechanical calculation and computer modelling of condensed media and nanostructures. More than 250 specialists took part in the Conference. They represented leading Russian scientific research centers and universities (National Research Centre "Kurchatov Institute", A.M. Prokhorov General Physics Institute, P.N. Lebedev Physical Institute, Troitsk Institute for Innovation and Fusion Research, Joint Institute for Nuclear Research, Moscow Institute of Physics and Tecnology and others) and leading scientific centers and universities from Germany, France, USA, Canada, Japan. We would like to thank heartily all of the speakers, participants, organizing and program committee members for their contribution to the conference.

Overview of the preliminary design of the ITER plasma control system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snipes, J. A.; Albanese, R.; Ambrosino, G.

An overview of the Preliminary Design of the ITER Plasma Control System (PCS) is described here, which focusses on the needs for 1st plasma and early plasma operation in hydrogen/helium (H/He) up to a plasma current of 15 MA with moderate auxiliary heating power in low confinement mode (L-mode). Candidate control schemes for basic magnetic control, including divertor operation and kinetic control of the electron density with gas puffing and pellet injection, were developed. Commissioning of the auxiliary heating systems is included as well as support functions for stray field topology and real-time plasma boundary reconstruction. Initial exception handling schemesmore » for faults of essential plant systems and for disruption protection were developed. The PCS architecture was also developed to be capable of handling basic control for early commissioning and the advanced control functions that will be needed for future high performance operation. A plasma control simulator is also being developed to test and validate control schemes. To handle the complexity of the ITER PCS, a systems engineering approach has been adopted with the development of a plasma control database to keep track of all control requirements.« less

Overview of the preliminary design of the ITER plasma control system

NASA Astrophysics Data System (ADS)

Snipes, J. A.; Albanese, R.; Ambrosino, G.; Ambrosino, R.; Amoskov, V.; Blanken, T. C.; Bremond, S.; Cinque, M.; de Tommasi, G.; de Vries, P. C.; Eidietis, N.; Felici, F.; Felton, R.; Ferron, J.; Formisano, A.; Gribov, Y.; Hosokawa, M.; Hyatt, A.; Humphreys, D.; Jackson, G.; Kavin, A.; Khayrutdinov, R.; Kim, D.; Kim, S. H.; Konovalov, S.; Lamzin, E.; Lehnen, M.; Lukash, V.; Lomas, P.; Mattei, M.; Mineev, A.; Moreau, P.; Neu, G.; Nouailletas, R.; Pautasso, G.; Pironti, A.; Rapson, C.; Raupp, G.; Ravensbergen, T.; Rimini, F.; Schneider, M.; Travere, J.-M.; Treutterer, W.; Villone, F.; Walker, M.; Welander, A.; Winter, A.; Zabeo, L.

2017-12-01

An overview of the preliminary design of the ITER plasma control system (PCS) is described here, which focusses on the needs for 1st plasma and early plasma operation in hydrogen/helium (H/He) up to a plasma current of 15 MA with moderate auxiliary heating power in low confinement mode (L-mode). Candidate control schemes for basic magnetic control, including divertor operation and kinetic control of the electron density with gas puffing and pellet injection, were developed. Commissioning of the auxiliary heating systems is included as well as support functions for stray field topology and real-time plasma boundary reconstruction. Initial exception handling schemes for faults of essential plant systems and for disruption protection were developed. The PCS architecture was also developed to be capable of handling basic control for early commissioning and the advanced control functions that will be needed for future high performance operation. A plasma control simulator is also being developed to test and validate control schemes. To handle the complexity of the ITER PCS, a systems engineering approach has been adopted with the development of a plasma control database to keep track of all control requirements.

Overview of the preliminary design of the ITER plasma control system

DOE PAGES

Snipes, J. A.; Albanese, R.; Ambrosino, G.; ...

2017-09-11

An overview of the Preliminary Design of the ITER Plasma Control System (PCS) is described here, which focusses on the needs for 1st plasma and early plasma operation in hydrogen/helium (H/He) up to a plasma current of 15 MA with moderate auxiliary heating power in low confinement mode (L-mode). Candidate control schemes for basic magnetic control, including divertor operation and kinetic control of the electron density with gas puffing and pellet injection, were developed. Commissioning of the auxiliary heating systems is included as well as support functions for stray field topology and real-time plasma boundary reconstruction. Initial exception handling schemesmore » for faults of essential plant systems and for disruption protection were developed. The PCS architecture was also developed to be capable of handling basic control for early commissioning and the advanced control functions that will be needed for future high performance operation. A plasma control simulator is also being developed to test and validate control schemes. To handle the complexity of the ITER PCS, a systems engineering approach has been adopted with the development of a plasma control database to keep track of all control requirements.« less

Narrow bandwidth Laser-Plasma Accelerator driven Thomson photon source development

NASA Astrophysics Data System (ADS)

Geddes, C. G. R.; Tsai, H.-E.; Otero, G.; Liu, X.; van Tilborg, J.; Toth, Cs.; Vay, J.-L.; Lehe, R.; Schroeder, C. B.; Esarey, E.; Friedman, A.; Grote, D. P.; Leemans, W. P.

2017-10-01

Compact, high-quality photon sources at MeV energies can be provided by Thomson scattering of a laser from the electron beam of a Laser-Plasma Accelerator (LPA). Recent experiments and simulations demonstrate controllable LPAs in the energy range appropriate to MeV sources. Simulations indicate that high flux with narrow energy spread can be achieved via control of the scattering laser pulse shape and laser guiding, and that undesired background bremsstrahlung can be mitigated by plasma based deceleration of the electron beam after photon production. Construction of experiments and laser capabilities to combine these elements will be presented, along with initial operations, towards a compact photon source system. Work supported by US DOE NNSA DNN R&D and by Sc. HEP under contract DE-AC02-05CH11231.

Integrated Plasma Control for Alternative Plasma Shape on EAST

NASA Astrophysics Data System (ADS)

Xiao, Bingjia

2017-10-01

To support long pulse plasma operation in high performance, a set of plasma control algorithms such as PEFIT real-time equilibrium reconstruction, radiation feedback, Beta and loop voltage feedback and quasi-snowflake shape f control have been implemented on EAST Plasma Control system (PCS) which was adapted from DIII-D PCS. PEFIT is a parallelized version of EFIT by using GPU with highest computation acceleration ratio up to 100 with respect to EFIT. It demonstrated high performance both in DIII-D data analysis and in the real-time shape control on EAST plasma either in normal or quasi-snowflake shape. Loop voltage has been successfully controlled by Low Hybrid Wave (LHW) while the plasma current is maintained by poloidal field coil set. Beta control has been also demonstrated by using LHW and it will be extended to other heating sources because the PCS interface is ready. Radiation feedback control has been achieved by Neon seeding by Super-Sonic Molecular Beam Injection (SMBI). For the plasma operation in quasi-snowflake, we have reached 20 s ELMy free high confinement non-inductive discharges with betap 2, H98 1.1 and plasma current 250 kA. EAST orals.

A study of GaN-based LED structure etching using inductively coupled plasma

NASA Astrophysics Data System (ADS)

Wang, Pei; Cao, Bin; Gan, Zhiyin; Liu, Sheng

2011-02-01

GaN as a wide band gap semiconductor has been employed to fabricate optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes (LDs). Recently several different dry etching techniques for GaN-based materials have been developed. ICP etching is attractive because of its superior plasma uniformity and strong controllability. Most previous reports emphasized on the ICP etching characteristics of single GaN film. In this study dry etching of GaN-based LED structure was performed by inductively coupled plasmas (ICP) etching with Cl2 as the base gas and BCl3 as the additive gas. The effects of the key process parameters such as etching gases flow rate, ICP power, RF power and chamber pressure on the etching properties of GaN-based LED structure including etching rate, selectivity, etched surface morphology and sidewall was investigated. Etch depths were measured using a depth profilometer and used to calculate the etch rates. The etch profiles were observed with a scanning electron microscope (SEM).

A blood-based screening tool for Alzheimer's disease that spans serum and plasma: findings from TARC and ADNI.

PubMed

O'Bryant, Sid E; Xiao, Guanghua; Barber, Robert; Huebinger, Ryan; Wilhelmsen, Kirk; Edwards, Melissa; Graff-Radford, Neill; Doody, Rachelle; Diaz-Arrastia, Ramon

2011-01-01

There is no rapid and cost effective tool that can be implemented as a front-line screening tool for Alzheimer's disease (AD) at the population level. To generate and cross-validate a blood-based screener for AD that yields acceptable accuracy across both serum and plasma. Analysis of serum biomarker proteins were conducted on 197 Alzheimer's disease (AD) participants and 199 control participants from the Texas Alzheimer's Research Consortium (TARC) with further analysis conducted on plasma proteins from 112 AD and 52 control participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). The full algorithm was derived from a biomarker risk score, clinical lab (glucose, triglycerides, total cholesterol, homocysteine), and demographic (age, gender, education, APOE*E4 status) data. Alzheimer's disease. 11 proteins met our criteria and were utilized for the biomarker risk score. The random forest (RF) biomarker risk score from the TARC serum samples (training set) yielded adequate accuracy in the ADNI plasma sample (training set) (AUC = 0.70, sensitivity (SN) = 0.54 and specificity (SP) = 0.78), which was below that obtained from ADNI cerebral spinal fluid (CSF) analyses (t-tau/Aβ ratio AUC = 0.92). However, the full algorithm yielded excellent accuracy (AUC = 0.88, SN = 0.75, and SP = 0.91). The likelihood ratio of having AD based on a positive test finding (LR+) = 7.03 (SE = 1.17; 95% CI = 4.49-14.47), the likelihood ratio of not having AD based on the algorithm (LR-) = 3.55 (SE = 1.15; 2.22-5.71), and the odds ratio of AD were calculated in the ADNI cohort (OR) = 28.70 (1.55; 95% CI = 11.86-69.47). It is possible to create a blood-based screening algorithm that works across both serum and plasma that provides a comparable screening accuracy to that obtained from CSF analyses.

Performance of target-controlled infusion of propofol using two different pharmacokinetic models in open heart surgery - a randomised controlled study.

PubMed

Mathew, P J; Sailam, S; Sivasailam, R; Thingnum, S K S; Puri, G D

2016-01-01

We compared the performance of a propofol target-controlled infusion (TCI) using Marsh versus PGIMER models in patients undergoing open heart surgery, in terms of measured plasma levels of propofol and objective pharmacodynamic effect. Twenty-three, ASA II/III adult patients aged 18-65 years and scheduled for elective open heart surgery received Marsh or PGIMER (Postgraduate Institute of Medical Education and Research) pharmacokinetic models of TCI for the induction and maintenance of anaesthesia with propofol in a randomized, active-controlled, non-inferiority trial. The plasma levels of propofol were measured at specified time points before, during and after bypass. The performances of both the models were similar, as determined by the error (%) in maintaining the target plasma concentrations: MDPE of -5.0 (-12.0, 5.0) in the PGIMER group vs -6.4 (-7.7 to 0.5) in the Marsh group and MDAPE of 9.1 (5, 15) in the PGIMER group vs 8 (6.7, 10.1) in the Marsh group. These values indicate that both models over-predicted the plasma propofol concentration. The new pharmacokinetic model based on data from Indian patients is comparable in performance to the commercially available Marsh pharmacokinetic model. © The Author(s) 2015.

Implementation of atomic layer etching of silicon: Scaling parameters, feasibility, and profile control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranjan, Alok, E-mail: alok.ranjan@us.tel.com; Wang, Mingmei; Sherpa, Sonam D.

2016-05-15

Atomic or layer by layer etching of silicon exploits temporally segregated self-limiting adsorption and material removal steps to mitigate the problems associated with continuous or quasicontinuous (pulsed) plasma processes: selectivity loss, damage, and profile control. Successful implementation of atomic layer etching requires careful choice of the plasma parameters for adsorption and desorption steps. This paper illustrates how process parameters can be arrived at through basic scaling exercises, modeling and simulation, and fundamental experimental tests of their predictions. Using chlorine and argon plasma in a radial line slot antenna plasma source as a platform, the authors illustrate how cycle time, ionmore » energy, and radical to ion ratio can be manipulated to manage the deviation from ideality when cycle times are shortened or purges are incomplete. Cell based Monte Carlo feature scale modeling is used to illustrate profile outcomes. Experimental results of atomic layer etching processes are illustrated on silicon line and space structures such that iso-dense bias and aspect ratio dependent free profiles are produced. Experimental results also illustrate the profile control margin as processes move from atomic layer to multilayer by layer etching. The consequence of not controlling contamination (e.g., oxygen) is shown to result in deposition and roughness generation.« less

Association between ascites and primary hyperfibrinolysis: A cohort study in 210 dogs.

PubMed

Zoia, Andrea; Drigo, Michele; Simioni, Paolo; Caldin, Marco; Piek, Christine J

2017-05-01

Coagulation profiles were determined in 70 dogs with ascites, 70 healthy control dogs and 70 sick control dogs without ascites. Dogs with ascites were divided into four sub-groups based on the pathophysiology of fluid formation. Coagulation profile, serum C-reactive protein and frequency of discordant plasma fibrin-fibrinogen degradation products and D-dimer assay results, suggesting primary hyperfibrinolysis, were compared between groups. Within the ascites group, 10 samples of ascitic fluid were transudates due to decreased osmotic pressure, 18 were transudates due to increased hydrostatic pressure, 13 were exudates and 29 were haemorrhagic. Plasma fibrinogen concentrations were significantly lower in dogs with ascites compared to sick dogs without ascites. Activated partial thromboplastin time, prothrombin time, plasma concentrations of fibrin-fibrinogen degradation products and D-dimers, and frequency of primary hyperfibrinolysis, were significantly higher for dogs with ascites compared to both control groups. There was no significant difference in platelet count between groups. The frequency of primary hyperfibrinolysis was highest in dogs with transudative ascites due to increased hydrostatic pressure. Serum C-reactive protein was significantly higher in dogs with ascites compared to both control groups, and significantly and positively correlated with plasma D-dimers. In conclusion, dogs with ascites have an increased frequency of primary hyperfibrinolysis, especially with ascites secondary to increased hydrostatic pressure. The increased inflammation present in these dogs may have activated haemostasis in some cases, explaining the higher plasma D-dimers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental investigations on characteristics of boundary layer and control of transition on an airfoil by AC-DBD

NASA Astrophysics Data System (ADS)

Geng, Xi; Shi, Zhiwei; Cheng, Keming; Dong, Hao; Zhao, Qun; Chen, Sinuo

2018-03-01

Plasma-based flow control is one of the most promising techniques for aerodynamic problems, such as delaying the boundary layer transition. The boundary layer’s characteristics induced by AC-DBD plasma actuators and applied by the actuators to delay the boundary layer transition on airfoil at Ma = 0.3 were experimentally investigated. The PIV measurement was used to study the boundary layer’s characteristics induced by the plasma actuators. The measurement plane, which was parallel to the surface of the actuators and 1 mm above the surface, was involved in the test, including the perpendicular plane. The instantaneous results showed that the induced flow field consisted of many small size unsteady vortices which were eliminated by the time average. The subsequent oil-film interferometry skin friction measurement was conducted on a NASA SC(2)-0712 airfoil at Ma = 0.3. The coefficient of skin friction demonstrates that the plasma actuators successfully delay the boundary layer transition and the efficiency is better at higher driven voltage.

Programmable Pulse Generator for Aditya Gas Puffing System

NASA Astrophysics Data System (ADS)

Patel, Narendra; Chavda, Chhaya; Bhatt, S. B.; Chattopadhyay, Prabal; Saxena, Y. C.

2012-11-01

In the Aditya Tokamak, one of primary requirement for plasma generation is to feed the required quantity of the fuel gas prior to plasma shot. Gas feed system mainly consists of piezoelectric gas leak valve and gas reservoir. The Hydrogen gas is prior to 300ms loop voltage for the duration of 4 msec to 7 msec. Gas is puffed during the shot for required plasma parameters and to increase plasma density using the same system. The valve is controlled by either continuous voltage or pulses of different width, amplitude and delay with respect to loop voltage. These voltage pulses are normally applied through standard pulse generator. The standard pulse generator is replaced by micro controller based in housed developed programmable pulse generator system consists of in built power supply, BNC input for external trigger, BNC output and serial interface. This programmable pulse generator is successfully tested and is in operation for gas puffing during ADITYA Tokamak experiments. The paper discusses the design and development aspect of the system.

Thermodynamic properties and transport coefficients of a two-temperature polytetrafluoroethylene vapor plasma for ablation-controlled discharge applications

NASA Astrophysics Data System (ADS)

Wang, Haiyan; Wang, Weizong; Yan, Joseph D.; Qi, Haiyang; Geng, Jinyue; Wu, Yaowu

2017-10-01

Ablation-controlled plasmas have been used in a range of technical applications where local thermodynamic equilibrium (LTE) is often violated near the wall due to the strong cooling effect caused by the ablation of wall materials. The thermodynamic and transport properties of ablated polytetrafluoroethylene (PTFE) vapor, which determine the flowing plasma behavior in such applications, are calculated based on a two-temperature model at atmospheric pressure. To our knowledge, no data for PTFE have been reported in the literature. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and the Guldberg-Waage equation according to van de Sanden et al’s derivation. The transport coefficients, including viscosity, thermal conductivity and electrical conductivity, are calculated with the most recent collision interaction potentials using Devoto’s electron and heavy-particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of the Chapman-Enskog method. Results are computed for different degrees of thermal non-equilibrium, i.e. the ratio of electron to heavy-particle temperatures, from 1 to 10, with electron temperature ranging from 300 to 40 000 K. Plasma transport properties in the LTE state obtained from the present work are compared with existing published results and the causes for the discrepancy analyzed. The two-temperature plasma properties calculated in the present work enable the modeling of wall ablation-controlled plasma processes.

Development of barrier coatings for cellulosic-based materials by cold plasma methods

NASA Astrophysics Data System (ADS)

Denes, Agnes Reka

Cellulose-based materials are ideal candidates for future industries that need to be based on environmentally safe technologies and renewable resources. Wood represents an important raw material and its application as construction material is well established. Cellophane is one of the most important cellulosic material and it is widely used as packaging material in the food industry. Outdoor exposure of wood causes a combination of physical and chemical degradation processes due to the combined effects of sunlight, moisture, fungi, and bacteria. Cold-plasma-induced surface modifications are an attractive way for tailoring the characteristics of lignocellulosic substrates to prevent weathering degradation. Plasma-polymerized hexamethyldisiloxane (PPHMDSO) was deposited onto wood surfaces to create water repellent characteristics. The presence of a crosslinked macromolecular structure was detected. The plasma coated samples exhibited very high water contact angle values indicating the existence of hydrophobic surfaces. Reflective and electromagnetic radiation-absorbent substances were incorporated with a high-molecular-weight polydimethylsiloxane polymer in liquid phase and deposited as thin layers on wood surfaces. The macromolecular films, containing the dispersed materials, were then converted into a three dimensional solid state network by exposure to a oxygen-plasma. It was demonstrated that both UV-absorbent and reflectant components incorporated into the plasma-generated PDMSO matrix protected the wood from weathering degradation. Reduced oxidation and less degradation was observed after simulated weathering. High water contact angle values indicated a strong hydrophobic character of the oxygen plasma-treated PDMSO-coated samples. Plasma-enhanced surface modifications and coatings were employed to create water-vapor barrier layers on cellophane substrate surfaces. HMDSO was selected as a plasma gas and oxygen was used to ablate amorphous regions. Oxygen plasma treated cellophane and oxygen plasma treated and PPHMDSO coated cellophane surfaces were comparatively analyzed and the corresponding surface wettability characteristics were evaluated. The plasma generated surface topographies controlled the morphology of the PPHMDSO layers. Higher temperature HMDSO plasma-state environments lead to insoluble, crosslinked layers. Continuous and pulsed Csb2Fsb6 plasmas were also used for surface modification and excellent surface fluorination was achieved under the pulsed plasma conditions.

Plasma equilibrium control during slow plasma current quench with avoidance of plasma-wall interaction in JT-60U

NASA Astrophysics Data System (ADS)

Yoshino, R.; Nakamura, Y.; Neyatani, Y.

1997-08-01

In JT-60U a vertical displacement event (VDE) is observed during slow plasma current quench (Ip quench) for a vertically elongated divertor plasma with a single null. The VDE is generated by an error in the feedback control of the vertical position of the plasma current centre (ZJ). It has been perfectly avoided by improving the accuracy of the ZJ measurement in real time. Furthermore, plasma-wall interaction has been avoided successfully during slow Ip quench owing to the good performance of the plasma equilibrium control system

Beam transport and monitoring for laser plasma accelerators

NASA Astrophysics Data System (ADS)

Nakamura, K.; Sokollik, T.; van Tilborg, J.; Gonsalves, A. J.; Shaw, B.; Shiraishi, S.; Mittal, R.; De Santis, S.; Byrd, J. M.; Leemans, W.

2012-12-01

The controlled transport and imaging of relativistic electron beams from laser plasma accelerators (LPAs) are critical for their diagnostics and applications. Here we present the design and progress in the implementation of the transport and monitoring system for an undulator based electron beam diagnostic. Miniature permanent-magnet quadrupoles (PMQs) are employed to realize controlled transport of the LPA electron beams, and cavity based electron beam position monitors for non-invasive beam position detection. Also presented is PMQ calibration by using LPA electron beams with broadband energy spectrum. The results show promising performance for both transporting and monitoring. With the proper transport system, XUV-photon spectra from THUNDER will provide the momentum distribution of the electron beam with the resolution above what can be achieved by the magnetic spectrometer currently used in the LOASIS facility.

Robust, Flexible and Lightweight Dielectric Barrier Discharge Actuators Using Nanofoams/Aerogels

NASA Technical Reports Server (NTRS)

Siochi, Emilie J. (Inventor); Sauti, Godfrey (Inventor); Wilkinson, Stephen P. (Inventor); Guo, Haiquan N. (Inventor); Xu, Tian-Bing (Inventor); Meador, Mary Ann B. (Inventor)

2015-01-01

Robust, flexible, lightweight, low profile enhanced performance dielectric barrier discharge actuators (plasma actuators) based on aerogels/nanofoams with controlled pore size and size distribution as well as pore shape. The plasma actuators offer high body force as well as high force to weight ratios (thrust density). The flexibility and mechanical robustness of the actuators allows them to be shaped to conform to the surface to which they are applied. Carbon nanotube (CNT) based electrodes serve to further decrease the weight and profile of the actuators while maintaining flexibility while insulating nano-inclusions in the matrix enable tailoring of the mechanical properties. Such actuators are required for flow control in aeronautics and moving machinery such as wind turbines, noise abatement in landing gear and rotary wing aircraft and other applications.

Nanoparticle forming reactive plasmas: a multidiagnostic approach

NASA Astrophysics Data System (ADS)

Hinz, Alexander; Wahl, Erik von; Faupel, Franz; Strunskus, Thomas; Kersten, Holger

2018-05-01

With an ever increasing interest in functional materials based on nanoparticles a large amount of research in this field is dedicated to the development of new production methods for nanoparticles. A promising class of methods for the production of nanoparticles is reactive plasmas. However, since the particle formation process and the interaction between the particles and the plasma are so far not completely understood, it remains difficult to control the particle formation. As the interaction between the nanoparticles and the plasma in which they are dispersed is complex the use of one or two diagnostics often provides only an incomplete understanding of the involved processes. Thus a multidiagnostic approach is needed. This contribution reviews the latest results from the study of nanoparticle formation in a hydrocarbon-based reactive plasma by such a multidiagnostic approach. It is shown that the use of various diagnostics like an IV-probe, optical emission spectroscopy, and a multipole resonance probe in conjunction with an investigation of the particle formation provides a much more detailed picture of these interesting, yet challenging, systems. Contribution to the Topical Issue "Fundamentals of Complex Plasmas", edited by Jürgen Meichsner, Michael Bonitz, Holger Fehske, Alexander Piel.

Shuttle wave experiments. [space plasma investigations: design and instrumentation

NASA Technical Reports Server (NTRS)

Calvert, W.

1976-01-01

Wave experiments on shuttle are needed to verify dispersion relations, to study nonlinear and exotic phenomena, to support other plasma experiments, and to test engineering designs. Techniques based on coherent detection and bistatic geometry are described. New instrumentation required to provide modules for a variety of missions and to incorporate advanced signal processing and control techniques is discussed. An experiment for Z to 0 coupling is included.

Effect of vehicle and route of administration of letrozole on ovarian function in a bovine model.

PubMed

Yapura, M J; Mapletoft, R J; Pierson, R A; Singh, J; Adams, G P

2014-10-01

The objective of this study was to determine the effects of vehicle and route of administration of letrozole on ovarian function in sexually mature beef heifers. On Day 3 (Day 0=ovulation), heifers were assigned randomly to four treatment groups and given 1mgkg(-1) letrozole intravenously (iv, n=10) or intramuscularly (im, n=10) or given a placebo iv (control iv, n=5) or im (control im, n=5). The interwave interval was longer in heifers treated with letrozole im than in im and iv controls (11.7±0.30 vs 9.5±0.50 and 10±0.43, respectively; P<0.05). Corpus luteum diameter profiles and plasma progesterone concentrations were greater (P<0.03 and P<0.05, respectively) in heifers treated with letrozole im compared with control im. Plasma oestradiol concentrations were lower in both letrozole-treated groups compared with controls (P≤0.03). Plasma LH concentrations tended to be elevated at the time of wave emergence in heifers treated with letrozole im compared with other groups (group-by-day interaction, P=0.06) and plasma FSH concentrations tended to be greater (P<0.09) in heifers treated with letrozole by either route compared with a single control group. We conclude that intramuscular administration of letrozole in oil is a feasible route and vehicle for the development of a letrozole-based treatment protocol for herd synchronisation in cattle.

Control of linear modes in cylindrical resistive magnetohydrodynamics with a resistive wall, plasma rotation, and complex gain

NASA Astrophysics Data System (ADS)

Brennan, D. P.; Finn, J. M.

2014-10-01

Feedback stabilization of magnetohydrodynamic (MHD) modes in a tokamak is studied in a cylindrical model with a resistive wall, plasma resistivity, viscosity, and toroidal rotation. The control is based on a linear combination of the normal and tangential components of the magnetic field just inside the resistive wall. The feedback includes complex gain, for both the normal and for the tangential components, and it is known that the imaginary part of the feedback for the former is equivalent to plasma rotation [J. M. Finn and L. Chacon, Phys. Plasmas 11, 1866 (2004)]. The work includes (1) analysis with a reduced resistive MHD model for a tokamak with finite β and with stepfunction current density and pressure profiles, and (2) computations with a full compressible visco-resistive MHD model with smooth decreasing profiles of current density and pressure. The equilibria are stable for β = 0 and the marginal stability values βrp,rw < βrp,iw < βip,rw < βip,iw (resistive plasma, resistive wall; resistive plasma, ideal wall; ideal plasma, resistive wall; and ideal plasma, ideal wall) are computed for both models. The main results are: (a) imaginary gain with normal sensors or plasma rotation stabilizes below βrp,iw because rotation suppresses the diffusion of flux from the plasma out through the wall and, more surprisingly, (b) rotation or imaginary gain with normal sensors destabilizes above βrp,iw because it prevents the feedback flux from entering the plasma through the resistive wall to form a virtual wall. A method of using complex gain Gi to optimize in the presence of rotation in this regime with β > βrp,iw is presented. The effect of imaginary gain with tangential sensors is more complicated but essentially destabilizes above and below βrp,iw.

The pH dependence of silicon-iron interaction in rats.

PubMed

Jia, X; Emerick, R J; Kayongo-Male, H

1997-01-01

A 2 x 2 x 3 factorial experiment was conducted to study the pH dependence of a silicon-iron interaction in vivo. The dietary treatments used in the factorial design were the following (mg/kg of diet): silicon, 0 and 500; iron, 35 and 187; acid-base, ammonium chloride as 0.5% of total diet (acidic), sodium bicarbonate as 1.0% of total diet (basic), or no supplementation of acid or base (control). The supplementation of 500 mg silicon/kg of diet increased plasma-iron concentration in rats fed the acidic or control diets, but not in rats fed the basic diet. A high dietary-iron level suppressed copper absorption and utilization and subsequently imposed a negative effect on its own utilization. An increase in the plasma total-cholesterol concentration caused by high dietary-iron level was likely a consequence of the antagonistic effect of iron on copper absorption and utilization. The use of cupric sulfate pentahydrate as the dietary-copper source in this study resulted in plasma copper concentrations that were approximately twice those obtained in a related study using cupric carbonate. Also, a 42% coefficient of variation (C.V.) for plasma-copper concentrations of rats fed cupric sulfate in this study was greatly reduced from the C.V. = 108% previously associated with the dietary cupric carbonate.

Interlaboratory trial for the measurement of total cobalt in equine urine and plasma by ICP-MS.

PubMed

Popot, Marie-Agnes; Ho, Emmie N M; Stojiljkovic, Natali; Bagilet, Florian; Remy, Pierre; Maciejewski, Pascal; Loup, Benoit; Chan, George H M; Hargrave, Sabine; Arthur, Rick M; Russo, Charlie; White, James; Hincks, Pamela; Pearce, Clive; Ganio, George; Zahra, Paul; Batty, David; Jarrett, Mark; Brooks, Lydia; Prescott, Lise-Anne; Bailly-Chouriberry, Ludovic; Bonnaire, Yves; Wan, Terence S M

2017-09-01

Cobalt is an essential mineral micronutrient and is regularly present in equine nutritional and feed supplements. Therefore, cobalt is naturally present at low concentrations in biological samples. The administration of cobalt chloride is considered to be blood doping and is thus prohibited. To control the misuse of cobalt, it was mandatory to establish an international threshold for cobalt in plasma and/or in urine. To achieve this goal, an international collaboration, consisting of an interlaboratory comparison between 5 laboratories for the urine study and 8 laboratories for the plasma study, has been undertaken. Quantification of cobalt in the biological samples was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Ring tests were based on the analysis of 5 urine samples supplemented at concentrations ranging from 5 up to 500 ng/mL and 5 plasma samples spiked at concentrations ranging from 0.5 up to 25 ng/mL. The results obtained from the different laboratories were collected, compiled, and compared to assess the reproducibility and robustness of cobalt quantification measurements. The statistical approach for the ring test for total cobalt in urine was based on the determination of percentage deviations from the calculated means, while robust statistics based on the calculated median were applied to the ring test for total cobalt in plasma. The inter-laboratory comparisons in urine and in plasma were successful so that 97.6% of the urine samples and 97.5% of the plasma samples gave satisfactory results. Threshold values for cobalt in plasma and urine were established from data only obtained by laboratories involved in the ring test. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Cereal based diets modulate some markers of oxidative stress and inflammation in lean and obese Zucker rats

PubMed Central

2011-01-01

Background The potential of cereals with high antioxidant capacity for reducing oxidative stress and inflammation in obesity is unknown. This study investigated the impact of wheat bran, barley or a control diet (α-cellulose) on the development of oxidative stress and inflammation in lean and obese Zucker rats. Methods Seven wk old, lean and obese male Zucker rats (n = 8/group) were fed diets that contained wheat bran, barley or α-cellulose (control). After 3 months on these diets, systolic blood pressure was measured and plasma was analysed for glucose, insulin, lipids, oxygen radical absorbance capacity (ORAC), malondialdehyde, glutathione peroxidase and adipokine concentration (leptin, adiponectin, interleukin (IL)-1β, IL-6, TNFα, plasminogen activator inhibitor (PAI)-1, monocyte chemotactic protein (MCP)-1). Adipokine secretion rates from visceral and subcutaneous adipose tissue explants were also determined. Results Obese rats had higher body weight, systolic blood pressure and fasting blood lipids, glucose, insulin, leptin and IL-1β in comparison to lean rats, and these measures were not reduced by consumption of wheat bran or barley based diets. Serum ORAC tended to be higher in obese rats fed wheat bran and barley in comparison to control (p = 0.06). Obese rats had higher plasma malondialdehyde (p < 0.01) and lower plasma glutathione peroxidase concentration (p < 0.01) but these levels were not affected by diet type. PAI-1 was elevated in the plasma of obese rats, and the wheat bran diet in comparison to the control group reduced PAI-1 to levels seen in the lean rats (p < 0.05). These changes in circulating PAI-1 levels could not be explained by PAI-1 secretion rates from visceral or subcutaneous adipose tissue. Conclusions A 3-month dietary intervention was sufficient for Zucker obese rats to develop oxidative stress and systemic inflammation. Cereal-based diets with moderate and high antioxidant capacity elicited modest improvements in indices of oxidative stress and inflammation. PMID:21535898

Flexible distributed architecture for semiconductor process control and experimentation

NASA Astrophysics Data System (ADS)

Gower, Aaron E.; Boning, Duane S.; McIlrath, Michael B.

1997-01-01

Semiconductor fabrication requires an increasingly expensive and integrated set of tightly controlled processes, driving the need for a fabrication facility with fully computerized, networked processing equipment. We describe an integrated, open system architecture enabling distributed experimentation and process control for plasma etching. The system was developed at MIT's Microsystems Technology Laboratories and employs in-situ CCD interferometry based analysis in the sensor-feedback control of an Applied Materials Precision 5000 Plasma Etcher (AME5000). Our system supports accelerated, advanced research involving feedback control algorithms, and includes a distributed interface that utilizes the internet to make these fabrication capabilities available to remote users. The system architecture is both distributed and modular: specific implementation of any one task does not restrict the implementation of another. The low level architectural components include a host controller that communicates with the AME5000 equipment via SECS-II, and a host controller for the acquisition and analysis of the CCD sensor images. A cell controller (CC) manages communications between these equipment and sensor controllers. The CC is also responsible for process control decisions; algorithmic controllers may be integrated locally or via remote communications. Finally, a system server images connections from internet/intranet (web) based clients and uses a direct link with the CC to access the system. Each component communicates via a predefined set of TCP/IP socket based messages. This flexible architecture makes integration easier and more robust, and enables separate software components to run on the same or different computers independent of hardware or software platform.

Profiling plasma extracellular vesicle by pluronic block-copolymer based enrichment method unveils features associated with breast cancer aggression, metastasis and invasion

PubMed Central

Rosenow, Matthew; Xiao, Nick; Spetzler, David

2018-01-01

ABSTRACT Extracellular vesicle (EV)-based liquid biopsies have been proposed to be a readily obtainable biological substrate recently for both profiling and diagnostics purposes. Development of a fast and reliable preparation protocol to enrich such small particles could accelerate the discovery of informative, disease-related biomarkers. Though multiple EV enrichment protocols are available, in terms of efficiency, reproducibility and simplicity, precipitation-based methods are most amenable to studies with large numbers of subjects. However, the selectivity of the precipitation becomes critical. Here, we present a simple plasma EV enrichment protocol based on pluronic block copolymer. The enriched plasma EV was able to be verified by multiple platforms. Our results showed that the particles enriched from plasma by the copolymer were EV size vesicles with membrane structure; proteomic profiling showed that EV-related proteins were significantly enriched, while high-abundant plasma proteins were significantly reduced in comparison to other precipitation-based enrichment methods. Next-generation sequencing confirmed the existence of various RNA species that have been observed in EVs from previous studies. Small RNA sequencing showed enriched species compared to the corresponding plasma. Moreover, plasma EVs enriched from 20 advanced breast cancer patients and 20 age-matched non-cancer controls were profiled by semi-quantitative mass spectrometry. Protein features were further screened by EV proteomic profiles generated from four breast cancer cell lines, and then selected in cross-validation models. A total of 60 protein features that highly contributed in model prediction were identified. Interestingly, a large portion of these features were associated with breast cancer aggression, metastasis as well as invasion, consistent with the advanced clinical stage of the patients. In summary, we have developed a plasma EV enrichment method with improved precipitation selectivity and it might be suitable for larger-scale discovery studies. PMID:29696079

A Preliminary Investigation of NSCL/P Plasma and Urine in Guizhou Province in China Using NMR-Based Metabonomics.

PubMed

Lei, Huang Guang; Hong, Luo; Kun, Song Ju; Hai, Yin Xin; Dong, Wang Ya; Ke, Zhao; Ping, Xu; Hao, Chen

2013-09-01

Objective : To assess the feasibility of metabonomics in clinical studies. This is a pilot study introducing nuclear magnetic resonance (NMR)-based metabonomics to elucidate and compare the metabolism of patients with nonsyndromic cleft lip and/or palate (NSCL/P) and children without orofacial clefts. Methods : High-resolution (1)H NMR spectroscopy was performed on plasma and urine samples obtained from NSCL/P and healthy children. The (1)H NMR spectra were further analyzed with principal component analysis. Results : Compared to the control group, the level of low-molecular-weight metabolites in plasma such as asparagine was higher in NSCL/P patients, while arginine, lysine, acetate, lactate, proline, glutamine, pyruvate, creatinine, choline, and β-glucose were lower. The carnitine, citrate, and formate excretion in urine appeared to be higher in the healthy children, while the NSCL/P group excreted higher concentrations of aspartic acid and phenylalanine in urine. Conclusion : The present study clearly demonstrated the great potential of NMR-based metabonomics in elucidating NSCL/P plasma metabolism and the possible application of this technology in clinical diagnosis and screening.

Label-free quantitative proteomic analysis of human plasma-derived microvesicles to find protein signatures of abdominal aortic aneurysms.

PubMed

Martinez-Pinna, Roxana; Gonzalez de Peredo, Anne; Monsarrat, Bernard; Burlet-Schiltz, Odile; Martin-Ventura, Jose Luis

2014-08-01

To find potential biomarkers of abdominal aortic aneurysms (AAA), we performed a differential proteomic study based on human plasma-derived microvesicles. Exosomes and microparticles isolated from plasma of AAA patients and control subjects (n = 10 each group) were analyzed by a label-free quantitative MS-based strategy. Homemade and publicly available software packages have been used for MS data analysis. The application of two kinds of bioinformatic tools allowed us to find differential protein profiles from AAA patients. Some of these proteins found by the two analysis methods belong to main pathological mechanisms of AAA such as oxidative stress, immune-inflammation, and thrombosis. Data analysis from label-free MS-based experiments requires the use of sophisticated bioinformatic approaches to perform quantitative studies from complex protein mixtures. The application of two of these bioinformatic tools provided us a preliminary list of differential proteins found in plasma-derived microvesicles not previously associated to AAA, which could help us to understand the pathological mechanisms related to this disease. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrical equivalent circuit for microstrip micro-plasma: control of EM propagation and numerical simulations.

PubMed

Mohamad, Almustafa; Tân-Hoa, Vuong; Jacques, David

2012-01-01

An approach to determine an equivalent electrical circuit of a micro planar discharge on a microstrip printed circuit is reported. The micro discharge is used to realize a dynamic microwave switching circuit. This approach is based on the measurement of the discharge current and the transmission coefficient for a given frequency 2.45 GHz. Numerical methods like FEM can be used to study the effect of plasma parameters on the propagation of electromagnetic waves through a microstrip printed circuit. Plasma behaves as flexible elements that can change its electrical proprieties such as conductivity.

Transport and Non-Invasive Position Detection of Electron Beams from Laser-Plasma Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osterhoff, J.; Nakamura, K.; Bakeman, M.

The controlled imaging and transport of ultra-relativistic electrons from laser-plasma accelerators is of crucial importance to further use of these beams, e.g. in high peak-brightness light sources. We present our plans to realize beam transport with miniature permanent quadrupole magnets from the electron source through our THUNDER undulator. Simulation results demonstrate the importance of beam imaging by investigating the generated XUV-photon flux. In addition, first experimental findings of utilizing cavity-based monitors for non-invasive beam-position measurements in a noisy electromagnetic laser-plasma environment are discussed.

Predictive Rotation Profile Control for the DIII-D Tokamak

NASA Astrophysics Data System (ADS)

Wehner, W. P.; Schuster, E.; Boyer, M. D.; Walker, M. L.; Humphreys, D. A.

2017-10-01

Control-oriented modeling and model-based control of the rotation profile are employed to build a suitable control capability for aiding rotation-related physics studies at DIII-D. To obtain a control-oriented model, a simplified version of the momentum balance equation is combined with empirical representations of the momentum sources. The control approach is rooted in a Model Predictive Control (MPC) framework to regulate the rotation profile while satisfying constraints associated with the desired plasma stored energy and/or βN limit. Simple modifications allow for alternative control objectives, such as maximizing the plasma rotation while maintaining a specified input torque. Because the MPC approach can explicitly incorporate various types of constraints, this approach is well suited to a variety of control objectives, and therefore serves as a valuable tool for experimental physics studies. Closed-loop TRANSP simulations are presented to demonstrate the effectiveness of the control approach. Supported by the US DOE under DE-SC0010661 and DE-FC02-04ER54698.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morishita, Sadaharu; Goto, Tetsuya; Nagase, Masaaki

Multiprocesses in a single plasma process chamber with high throughput require precise, sequential, high-speed alteration of partial pressures of multiple gas species. A conventional gas-distribution system cannot realize this because the system seriously overshoots gas pressure immediately following valve operation. Furthermore, chamber volume and conductance of gas piping between the system and chamber should both be considered because they delay the stabilizing time of gas pressure. Therefore, the authors proposed a new gas-distribution system without overshoot by controlling gas flow rate based on pressure measurement, as well as a method of pulse-controlled gas injection immediately following valve operation. Time variationmore » of measured partial pressure agrees well with a calculation based on an equivalent-circuit model that represents the chamber and gas piping between the system and chamber. Using pulse-controlled gas injection, the stabilizing time can be reduced drastically to 0.6 s for HBr added to pure Ar plasma, and 0.7 s for O{sub 2} added to Ar/HBr plasma; without the pulse control, the stabilizing times are 3 and 7 s, respectively. In the O{sub 2} addition case, rapid stabilization can be achieved during the period of line/space pattern etching of poly-Si on a thin SiO{sub 2} film. This occurs without anomalous etching of the underlying SiO{sub 2} film or the Si substrate near the sidewall, thus obtaining a wide process margin with high throughput.« less

First operation and effect of a new tandem-type ion source based on electron cyclotron resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kato, Yushi, E-mail: kato@eei.eng.osaka-u.ac.jp; Kimura, Daiju; Yano, Keisuke

A new tandem type source has been constructed on the basis of electron cyclotron resonance plasma for producing synthesized ion beams in Osaka University. Magnetic field in the first stage consists of all permanent magnets, i.e., cylindrically comb shaped one, and that of the second stage consists of a pair of mirror coil, a supplemental coil and the octupole magnets. Both stage plasmas can be individually operated, and produced ions in which is energy controlled by large bore extractor also can be transported from the first to the second stage. We investigate the basic operation and effects of the tandemmore » type electron cyclotron resonance ion source (ECRIS). Analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas in dual plasmas operation as well as each single operation. We describe construction and initial experimental results of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source in future.« less

Plasma metabolomics profiling of maintenance hemodialysis based on capillary electrophoresis - time of flight mass spectrometry.

PubMed

Liu, Shuxin; Wang, Lichao; Hu, Chunxiu; Huang, Xin; Liu, Hong; Xuan, Qiuhui; Lin, Xiaohui; Peng, Xiaojun; Lu, Xin; Chang, Ming; Xu, Guowang

2017-08-15

Uremia has been a rapidly increasing health problem in China. Hemodialysis (HD) is the main renal replacement therapy for uremia. The results of large-scale clinical trials have shown that the HD pattern is crucial for long-term prognosis of maintenance hemodialysis (MHD) in uremic patients. Plasma metabolism is very important for revealing the biological insights linked to the therapeutic effects of the HD pattern on uremia. Alteration of plasma metabolites in uremic patients in response to HD therapy has been reported. However, HD-pattern-dependent changes in plasma metabolites remain poorly understood. To this end, a capillary electrophoresis-time of flight mass spectrometry (CE-TOF/MS)-based metabolomics method was performed to systemically study the differences between HD and high flux hemodialysis (HFD) on plasma metabolite changes in patients. Three hundred and one plasma samples from three independent human cohorts (i.e., healthy controls, patients with pre-HD/post-HD, and patients with pre-HFD/post-HFD) were used in this study. Metabolites significantly changed (p < 0.05) after a single HD or HFD process. However, 11 uremic retention solutes could be more efficiently removed by HFD. Our findings indicate that a CE-TOF/MS-based metabolomics approach is promising for providing novel insights into understanding the effects of different dialysis methods on metabolite alterations of uremia.

ECR apparatus with magnetic coil for plasma refractive index control

DOEpatents

Berry, L.A.

1994-04-26

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figures.

ECR apparatus with magnetic coil for plasma refractive index control

DOEpatents

Berry, Lee A.

1994-01-01

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design.

Controlled Electron Injection into Plasma Accelerators and SpaceCharge Estimates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fubiani, Gwenael G.J.

2005-09-01

Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 10 18 - 10 19 cm -3, the accelerating fields and scale length can hence be on the order of 10-100GV/m and 10-40 μm, respectively. The production of quasimonoenergetic beams wasmore » recently obtained in a regime relying on self-trapping of background plasma electrons, using a single laser pulse for wakefield generation. In this dissertation, we study the controlled injection via the beating of two lasers (the pump laser pulse creating the plasma wave and a second beam being propagated in opposite direction) which induce a localized injection of background plasma electrons. The aim of this dissertation is to describe in detail the physics of optical injection using two lasers, the characteristics of the electron beams produced (the micrometer scale plasma wavelength can result in femtosecond and even attosecond bunches) as well as a concise estimate of the effects of space charge on the dynamics of an ultra-dense electron bunch with a large energy spread.« less

The change of plasma galectin-3 concentrations after traumatic brain injury.

PubMed

Shen, Yong-Feng; Yu, Wen-Hua; Dong, Xiao-Qiao; Du, Quan; Yang, Ding-Bo; Wu, Gang-Qun; Zhang, Zu-Yong; Wang, Hao; Jiang, Li

2016-05-01

Galectin-3 plays a significant role in microglia activation. Its increased circulating concentration has been associated with some inflammatory diseases. In-hospital major adverse events (IMAEs), including acute traumatic coagulopathy, progressive hemorrhagic injury and posttraumatic cerebral infarction, have high prevalence and are strong predictors of mortality after severe traumatic brain injury (STBI). The present study was designed to investigate the relationships between plasma galectin-3 concentrations and trauma severity, in-hospital mortality and IMAEs following STBI. Plasma galectin-3 concentrations of 100 STBI patients and 100 controls were determined. Diagnosis of progressive hemorrhagic injury and posttraumatic cerebral infarction was made on the follow-up computerized tomography scan. Acute traumatic coagulopathy was defined based on coagulation test. Plasma galectin-3 concentrations were significantly higher in patients as compared to controls and also associated highly with Glasgow Coma Scale scores and plasma C-reactive protein concentrations. Galectin-3 emerged as an independent predictor for in-hospital mortality and IMAEs. Areas under receiver operating characteristic curve of plasma galectin-3 concentrations were similar to those of Glasgow Coma Scale scores for prediction of in-hospital morality and IMAEs. Plasma galectin-3 concentrations have close relation to inflammation, trauma severity and clinical outcome, suggesting that galectin-3 should have the potential to be a good prognostic biomarker after STBI. Copyright © 2016 Elsevier B.V. All rights reserved.

Electromagnetic Modeling of the Passive Stabilization Loop at EAST

NASA Astrophysics Data System (ADS)

Ji, Xiang; Song, Yuntao; Wu, Songtao; Wang, Zhibin; Shen, Guang; Liu, Xufeng; Cao, Lei; Zhou, Zibo; Peng, Xuebing; Wang, Chenghao

2012-09-01

A passive stabilization loop (PSL) has been designed and manufactured in order to enhance the control of vertical instability and accommodate the new stage for high-performance plasma at EAST. Eddy currents are induced by vertical displacement events (VDEs) and disruption, which can produce a magnetic field to control the vertical instability of the plasma in a short timescale. A finite element model is created and meshed using ANSYS software. Based on the simulation of plasma VDEs and disruption, the distribution and decay curve of the eddy currents on the PSL are obtained. The largest eddy current is 200 kA and the stress is 68 MPa at the outer current bridge, which is the weakest point of the PSL because of the eddy currents and the magnetic fields. The analysis results provide the supporting data for the structural design.

COMBAT: Initial experience with a randomized clinical trial of plasma-based resuscitation in the field for traumatic hemorrhagic shock

PubMed Central

Chapman, Michael P.; Moore, Ernest E.; Chin, Theresa L; Ghasabyan, Arsen; Chandler, James; Stringham, John; Gonzalez, Eduardo; Moore, Hunter B.; Banerjee, Anirban; Silliman, Christopher C; Sauaia, Angela

2015-01-01

The existing evidence shows great promise for plasma as the first resuscitation fluid in both civilian and military trauma. We embarked on the Control of Major Bleeding After Trauma (COMBAT) trial with the support of the Department of Defense, in order to determine if plasma-first resuscitation yields hemostatic and survival benefits. The methodology of the COMBAT study represents not only three years of development work, but the integration of nearly two-decades of technical experience with the design and implementation of other clinical trials and studies. Herein, we describe the key features of the study design, critical personnel and infrastructural elements, and key innovations. We will also briefly outline the systems engineering challenges entailed by this study. COMBAT is a randomized, placebo controlled, semi-blinded prospective Phase IIB clinical trial, conducted in a ground ambulance fleet based at a Level I trauma center, and part of a multicenter collaboration. The primary objective of COMBAT is to determine the efficacy of field resuscitation with plasma first, compared to standard of care (normal saline). To date we have enrolled 30 subjects in the COMBAT study. The ability to achieve intervention with a hemostatic resuscitation agent in the closest possible temporal proximity to injury is critical and represents an opportunity to forestall the evolution of the “bloody vicious cycle”. Thus, the COMBAT model for deploying plasma in first response units should serve as a model for RCTs of other hemostatic resuscitative agents. PMID:25784527

Plasma viral microRNA profiles reveal potential biomarkers for chronic active Epstein-Barr virus infection.

PubMed

Kawano, Yoshihiko; Iwata, Seiko; Kawada, Jun-ichi; Gotoh, Kensei; Suzuki, Michio; Torii, Yuka; Kojima, Seiji; Kimura, Hiroshi; Ito, Yoshinori

2013-09-01

Chronic active Epstein-Barr virus (CAEBV) infection has high mortality and morbidity, and biomarkers for disease severity and prognosis are required. MicroRNAs (miRNAs) are small noncoding RNAs, and EBV encodes multiple miRNAs. Because plasma contains sufficiently stable miRNAs, circulating EBV-associated miRNA profiles were investigated as novel biomarkers in CAEBV infection. Plasma miRNA expression was assessed for 12 miRNAs encoded within 2 EBV open reading frames (BART and BHRF). Expression levels were investigated in 19 patients with CAEBV infection, 14 patients with infectious mononucleosis, and 11 healthy controls. Relative expression levels of plasma miRNAs were determined by TaqMan probe-based quantitative assay. Plasma miR-BART1-5p, 2-5p, 5, and 22 levels in patients with CAEBV infection were significantly greater than those in patients with infectious mononucleosis and in controls. Plasma miR-BART2-5p, 4, 7, 13, 15, and 22 levels were significantly elevated in patients with CAEBV infection with systemic symptoms, compared with levels in patients with no systemic symptoms. The levels of miR-BART2-5p, 13, and 15 showed clinical cutoff values associated with specific clinical conditions, in contrast to plasma EBV loads. Levels of specific plasma EBV miRNAs were elevated differentially in patients with CAEBV infection. Several EBV miRNAs, particularly miR-BART2-5p, 13, and 15, are potentially biomarkers of disease severity or prognosis.

The influence of nevirapine and efavirenz-based anti-retroviral therapy on the pharmacokinetics of lumefantrine and anti-malarial dose recommendation in HIV-malaria co-treatment.

PubMed

Maganda, Betty A; Ngaimisi, Eliford; Kamuhabwa, Appolinary A R; Aklillu, Eleni; Minzi, Omary M S

2015-04-25

HIV-malaria co-infected patients in most parts of sub-Saharan Africa are treated with both artemether-lumefantrine (AL) and efavirenz (EFV) or nevirapine (NVP)-based antiretroviral therapy (ART). EFV, NVP, artemether and lumefantrine are substrates, inhibitors or inducers of CYP3A4 and CYP2B6, creating a potential for drug-drug interactions. The effect of EFV and/or NVP on lumefantrine pharmacokinetic profile among HIV-malaria co-infected patients on ART and treated with AL was investigated. Optimal lumefantrine dosage regimen for patients on EFV-based ART was determined by population pharmacokinetics and simulation. This was a non-randomized, open label, parallel, prospective cohort study in which 128, 66 and 75 HIV-malaria co-infected patients on NVP-based ART (NVP-arm), EFV-based ART (EFV-arm) and ART naïve (control-am) were enrolled, respectively. Patients were treated with AL and contributed sparse venous plasma samples. Pharmacokinetic analysis of lumefantrine was done using non-linear mixed effect modelling. Of the evaluated models, a two-compartment pharmacokinetic model with first order absorption and lag-time described well lumefantrine plasma concentrations time profile. Patients in the EFV-arm but not in the NVP-arm had significantly lower lumefantrine bioavailability compared to that in the control-arm. Equally, 32% of patients in the EFV-arm had day-7 lumefantrine plasma concentrations below 280 ng/ml compared to only 4% in the control-arm and 3% in the NVP-arm. Upon post hoc simulation of lumefantrine exposure, patients in the EFV-arm had lower exposure (median (IQR)) compared to that in the control-arm; AUC0-inf; was 303,130 (211,080-431,962) versus 784,830 (547,405-1,116,250); day-7 lumefantrine plasma concentrations was: 335.5 (215.8-519.5) versus 858.7 (562.3-1,333.8), respectively. The predictive model through simulation of lumefantrine exposure at different dosage regimen scenarios for patients on EFV-based ART, suggest that AL taken twice daily for five days using the current dose could improve lumefantrine exposure and consequently malaria treatment outcomes. Co-treatment of AL with EFV-based ART but not NVP-based ART significantly reduces lumefantrine bioavailability and consequently total exposure. To ensure adequate lumefantrine exposure and malaria treatment success in HIV-malaria co-infected patients on EFV-based ART, an extension of the duration of AL treatment to five days using the current dose is proposed.

Non-thermal Plasma Activates Human Keratinocytes by Stimulation of Antioxidant and Phase II Pathways

PubMed Central

Schmidt, Anke; Dietrich, Stephan; Steuer, Anna; Weltmann, Klaus-Dieter; von Woedtke, Thomas; Masur, Kai; Wende, Kristian

2015-01-01

Non-thermal atmospheric pressure plasma provides a novel therapeutic opportunity to control redox-based processes, e.g. wound healing, cancer, and inflammatory diseases. By spatial and time-resolved delivery of reactive oxygen and nitrogen species, it allows stimulation or inhibition of cellular processes in biological systems. Our data show that both gene and protein expression is highly affected by non-thermal plasma. Nuclear factor erythroid-related factor 2 (NRF2) and phase II enzyme pathway components were found to act as key controllers orchestrating the cellular response in keratinocytes. Additionally, glutathione metabolism, which is a marker for NRF2-related signaling events, was affected. Among the most robustly increased genes and proteins, heme oxygenase 1, NADPH-quinone oxidoreductase 1, and growth factors were found. The roles of NRF2 targets, investigated by siRNA silencing, revealed that NRF2 acts as an important switch for sensing oxidative stress events. Moreover, the influence of non-thermal plasma on the NRF2 pathway prepares cells against exogenic noxae and increases their resilience against oxidative species. Via paracrine mechanisms, distant cells benefit from cell-cell communication. The finding that non-thermal plasma triggers hormesis-like processes in keratinocytes facilitates the understanding of plasma-tissue interaction and its clinical application. PMID:25589789

Colloidal crystal based plasma polymer patterning to control Pseudomonas aeruginosa attachment to surfaces.

PubMed

Pingle, Hitesh; Wang, Peng-Yuan; Thissen, Helmut; McArthur, Sally; Kingshott, Peter

2015-12-02

Biofilm formation on medical implants and subsequent infections are a global problem. A great deal of effort has focused on developing chemical contrasts based on micro- and nanopatterning for studying and controlling cells and bacteria at surfaces. It has been known that micro- and nanopatterns on surfaces can influence biomolecule adsorption, and subsequent cell and bacterial adhesion. However, less focus has been on precisely controlling patterns to study the initial bacterial attachment mechanisms and subsequently how the patterning influences the role played by biomolecular adsorption on biofilm formation. In this work, the authors have used colloidal self-assembly in a confined area to pattern surfaces with colloidal crystals and used them as masks during allylamine plasma polymer (AAMpp) deposition to generate highly ordered patterns from the micro- to the nanoscale. Polyethylene glycol (PEG)-aldehyde was grafted to the plasma regions via "cloud point" grafting to prevent the attachment of bacteria on the plasma patterned surface regions, thereby controlling the adhesive sites by choice of the colloidal crystal morphology. Pseudomonas aeruginosa was chosen to study the bacterial interactions with these chemically patterned surfaces. Scanning electron microscope, x-ray photoelectron spectroscopy (XPS), atomic force microscopy, and epifluorescence microscopy were used for pattern characterization, surface chemical analysis, and imaging of attached bacteria. The AAMpp influenced bacterial attachment because of the amine groups displaying a positive charge. XPS results confirm the successful grafting of PEG on the AAMpp surfaces. The results showed that PEG patterns can be used as a surface for bacterial patterning including investigating the role of biomolecular patterning on bacterial attachment. These types of patterns are easy to fabricate and could be useful in further applications in biomedical research.

Laboratory development and testing of spacecraft diagnostics

NASA Astrophysics Data System (ADS)

Amatucci, William; Tejero, Erik; Blackwell, Dave; Walker, Dave; Gatling, George; Enloe, Lon; Gillman, Eric

2017-10-01

The Naval Research Laboratory's Space Chamber experiment is a large-scale laboratory device dedicated to the creation of large-volume plasmas with parameters scaled to realistic space plasmas. Such devices make valuable contributions to the investigation of space plasma phenomena under controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. However, in addition to investigations such as plasma wave and instability studies, such devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this talk, we will describe how the laboratory simulation of space plasmas made this development path possible. Work sponsored by the US Naval Research Laboratory Base Program.

The DIII-D Plasma Control System as a Scientific Research Tool

NASA Astrophysics Data System (ADS)

Hyatt, A. W.; Ferron, J. R.; Humphreys, D. A.; Leuer, J. A.; Walker, M. L.; Welander, A. S.

2006-10-01

The digital plasma control system (PCS) is an essential element of the DIII-D tokamak as a scientific research instrument, providing experimenters with real-time measurement and control of the plasma equilibrium, heating, current drive, transport, stability, and plasma-wall interactions. A wide range of sensors and actuators allow feedback control not only of global quantities such as discharge shape, plasma energy, and toroidal rotation, but also of non-axisymmetric magnetic fields and features of the internal profiles of temperature and current density. These diverse capabilities of the PCS improve the effectiveness of tokamak operation and enable unique physics experiments. We will present an overview of the PCS and the systems it controls and interacts with, and show examples of various plasma parameters controlled by the PCS and its actuators.

Integrated simulations of H-mode operation in ITER including core fuelling, divertor detachment and ELM control

NASA Astrophysics Data System (ADS)

Polevoi, A. R.; Loarte, A.; Dux, R.; Eich, T.; Fable, E.; Coster, D.; Maruyama, S.; Medvedev, S. Yu.; Köchl, F.; Zhogolev, V. E.

2018-05-01

ELM mitigation to avoid melting of the tungsten (W) divertor is one of the main factors affecting plasma fuelling and detachment control at full current for high Q operation in ITER. Here we derive the ITER operational space, where ELM mitigation to avoid melting of the W divertor monoblocks top surface is not required and appropriate control of W sources and radiation in the main plasma can be ensured through ELM control by pellet pacing. We apply the experimental scaling that relates the maximum ELM energy density deposited at the divertor with the pedestal parameters and this eliminates the uncertainty related with the ELM wetted area for energy deposition at the divertor and enables the definition of the ITER operating space through global plasma parameters. Our evaluation is thus based on this empirical scaling for ELM power loads together with the scaling for the pedestal pressure limit based on predictions from stability codes. In particular, our analysis has revealed that for the pedestal pressure predicted by the EPED1  +  SOLPS scaling, ELM mitigation to avoid melting of the W divertor monoblocks top surface may not be required for 2.65 T H-modes with normalized pedestal densities (to the Greenwald limit) larger than 0.5 to a level of current of 6.5–7.5 MA, which depends on assumptions on the divertor power flux during ELMs and between ELMs that expand the range of experimental uncertainties. The pellet and gas fuelling requirements compatible with control of plasma detachment, core plasma tungsten accumulation and H-mode operation (including post-ELM W transient radiation) have been assessed by 1.5D transport simulations for a range of assumptions regarding W re-deposition at the divertor including the most conservative assumption of zero prompt re-deposition. With such conservative assumptions, the post-ELM W transient radiation imposes a very stringent limit on ELM energy losses and the associated minimum required ELM frequency. Depending on W transport assumptions during the ELM, a maximum ELM frequency is also identified above which core tungsten accumulation takes place.

Time-dependent modeling of dust injection in semi-detached ITER divertor plasma

NASA Astrophysics Data System (ADS)

Smirnov, Roman; Krasheninnikov, Sergei

2017-10-01

At present, it is generally understood that dust related issues will play important role in operation of the next step fusion devices, i.e. ITER, and in the development of future fusion reactors. Recent progress in research on dust in magnetic fusion devises has outlined several topics of particular concern: a) degradation of fusion plasma performance; b) impairment of in-vessel diagnostic instruments; and c) safety issues related to dust reactivity and tritium retention. In addition, observed dust events in fusion edge plasmas are highly irregular and require consideration of temporal evolution of both the dust and the fusion plasma. In order to address the dust-related fusion performance issues, we have coupled the dust transport code DUSTT and the edge plasma transport code UEDGE in time-dependent manner, allowing modeling of transient dust-induced phenomena in fusion edge plasmas. Using the coupled codes we simulate burst-like injection of tungsten dust into ITER divertor plasma in semi-detached regime, which is considered as preferable ITER divertor operational mode based on the plasma and heat load control restrictions. Analysis of transport of the dust and the dust-produced impurities, and of dynamics of the ITER divertor and edge plasma in response to the dust injection will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under Award Number DE-FG02-06ER54852.

Optical properties of relativistic plasma mirrors

PubMed Central

Vincenti, H.; Monchocé, S.; Kahaly, S.; Bonnaud, G.; Martin, Ph.; Quéré, F.

2014-01-01

The advent of ultrahigh-power femtosecond lasers creates a need for an entirely new class of optical components based on plasmas. The most promising of these are known as plasma mirrors, formed when an intense femtosecond laser ionizes a solid surface. These mirrors specularly reflect the main part of a laser pulse and can be used as active optical elements to manipulate its temporal and spatial properties. Unfortunately, the considerable pressures exerted by the laser can deform the mirror surface, unfavourably affecting the reflected beam and complicating, or even preventing, the use of plasma mirrors at ultrahigh intensities. Here we derive a simple analytical model of the basic physics involved in laser-induced deformation of a plasma mirror. We validate this model numerically and experimentally, and use it to show how such deformation might be mitigated by appropriate control of the laser phase. PMID:24614748

Digital Plasma Control System for Alcator C-Mod

NASA Astrophysics Data System (ADS)

Ferrara, M.; Wolfe, S.; Stillerman, J.; Fredian, T.; Hutchinson, I.

2004-11-01

A digital plasma control system (DPCS) has been designed to replace the present C-Mod system, which is based on hybrid analog-digital computer. The initial implementation of DPCS comprises two 64 channel, 16 bit, low-latency cPCI digitizers, each with 16 analog outputs, controlled by a rack-mounted single-processor Linux server, which also serves as the compute engine. A prototype system employing three older 32 channel digitizers was tested during the 2003-04 campaign. The hybrid's linear PID feedback system was emulated by IDL code executing a synchronous loop, using the same target waveforms and control parameters. Reliable real-time operation was accomplished under a standard Linux OS (RH9) by locking memory and disabling interrupts during the plasma pulse. The DPCS-computed outputs agreed to within a few percent with those produced by the hybrid system, except for discrepancies due to offsets and non-ideal behavior of the hybrid circuitry. The system operated reliably, with no sample loss, at more than twice the 10kHz design specification, providing extra time for implementing more advanced control algorithms. The code is fault-tolerant and produces consistent output waveforms even with 10% sample loss.

Plasma Exosomal miRNA-122-5p and miR-300-3p as Potential Markers for Transient Ischaemic Attack in Rats.

PubMed

Li, Dong-Bin; Liu, Jing-Li; Wang, Wei; Luo, Xiu-Mei; Zhou, Xia; Li, Jin-Pin; Cao, Xiao-Li; Long, Xiao-Hong; Chen, Jia-Gui; Qin, Chao

2018-01-01

Background: Differentiation of transient ischaemic attack (TIA) from ischaemic stroke within the thrombolysis time window is difficult. Although TIA may be diagnosed within this window, the latest imaging technologies are complex and costly. Serum markers, which are non-invasive, rapid and economic, are used for diagnosis and prognosis of various diseases. Exosome-derived miRNA markers for TIA are unknown. Methods: We examined focal brain ischaemia produced by occlusion of the middle cerebral artery (MCAo) for 5 min, 10 min, and 2 h in rats. Exosomal miRNAs with consistent trends in cerebrospinal fluid (CSF) and plasma were identified by deep sequencing and quantitative real-time polymerase chain reaction (qRT-PCR). The areas under the curve (AUC) of the receiver operating characteristic (ROC) curve were used to evaluate the diagnostic accuracy of these miRNAs for TIA in rats. Results: Rno-miR-122-5p and rno-miR-300-3p were selected. Plasma exosomal rno-miR-122-5p was significantly downregulated in 10 min ischaemic rats compared with control and 5 min plasma. Plasma exosomal rno-miR-300-3p was significantly upregulated in 5 min ischaemic rats compared with control, 10 min and 2 h rats. Plasma and CSF levels of these miRNAs were correlated. ROC analysis showed high AUC values for rno-miR-122-5p (0.960) and rno-miR-300-3p (0.970) in the 10 and 5 min rats, respectively, compared with controls. Conclusions: Plasma exosomal rno-miR-122-5p and rno-miR-300-3p may be blood-based TIA biomarkers.

Laser-driven electron beam and radiation sources for basic, medical and industrial sciences.

PubMed

Nakajima, Kazuhisa

2015-01-01

To date active research on laser-driven plasma-based accelerators have achieved great progress on production of high-energy, high-quality electron and photon beams in a compact scale. Such laser plasma accelerators have been envisaged bringing a wide range of applications in basic, medical and industrial sciences. Here inheriting the groundbreaker's review article on "Laser Acceleration and its future" [Toshiki Tajima, (2010)],(1)) we would like to review recent progress of producing such electron beams due to relativistic laser-plasma interactions followed by laser wakefield acceleration and lead to the scaling formulas that are useful to design laser plasma accelerators with controllability of beam energy and charge. Lastly specific examples of such laser-driven electron/photon beam sources are illustrated.

Reduction in plasma total homocysteine through increasing folate intake in healthy individuals is not associated with changes in measures of antioxidant activity or oxidant damage.

PubMed

Moat, S J; Hill, M H; McDowell, I F W; Pullin, C H; Ashfield-Watt, P A L; Clark, Z E; Whiting, J M; Newcombe, R G; Lewis, M J; Powers, H J

2003-03-01

Various mechanisms have been proposed to explain the association between plasma total homocysteine (tHcy) and risk of cardiovascular disease, including oxidative activity of homocysteine. To explore the putative role of reactive oxygen species in the association between plasma tHcy and risk of cardiovascular disease in healthy individuals. A double-blind, placebo-controlled crossover intervention to increase folate intake through diet (increased consumption of folate-rich foods) and supplement (400 micro g folic acid) was carried out in 126 healthy men and women. Measurements were made of antioxidant activity in red blood cells and plasma, and products of oxidant damage in plasma. Diet and supplement-based interventions led to an increase in measures of folate status and a reduction in plasma tHcy. This was not associated with any significant change in measures of antioxidant activity (plasma and red blood cell glutathione peroxidase activity and red blood cell superoxide dismutase activity) or oxidant damage (plasma malondialdehyde), although an improvement in plasma total antioxidant capacity just failed to reach significance. In healthy individuals lowering plasma tHcy does not have any functional implications regarding oxidative damage.

Altered metabolites in the plasma of autism spectrum disorder: a capillary electrophoresis time-of-flight mass spectroscopy study.

PubMed

Kuwabara, Hitoshi; Yamasue, Hidenori; Koike, Shinsuke; Inoue, Hideyuki; Kawakubo, Yuki; Kuroda, Miho; Takano, Yosuke; Iwashiro, Norichika; Natsubori, Tatsunobu; Aoki, Yuta; Kano, Yukiko; Kasai, Kiyoto

2013-01-01

Clinical diagnosis and severity of autism spectrum disorders (ASD) are determined by trained clinicians based on clinical evaluations of observed behaviors. As such, this approach is inevitably dependent on the expertise and subjective assessment of those administering the clinical evaluations. There is a need to identify objective biological markers associated with diagnosis or clinical severity of the disorder. To identify novel candidate metabolites as potential biomarkers for ASD, the current study applied capillary electrophoresis time-of-flight mass spectroscopy (CE-TOFMS) for high-throughput profiling of metabolite levels in the plasma of 25 psychotropic-naïve adult males with high-functioning ASD and 28 age-matched typically-developed control subjects. Ten ASD participants and ten age-matched controls were assigned in the first exploration set, while 15 ASD participants and 18 controls were included in the second replication set. By CE-TOFMS analysis, a total of 143 metabolites were detected in the plasma of the first set. Of these, 17 metabolites showed significantly different relative areas between the ASD participants and the controls (p<0.05). Of the 17 metabolites, we consistently found that the ASD participants had significantly high plasma levels of arginine (p = 0.024) and taurine (p = 0.018), and significantly low levels of 5-oxoproline (p<0.001) and lactic acid (p = 0.031) compared with the controls in the second sample set. Further confirmatory analysis using quantification of absolute metabolite concentrations supported the robustness of high arginine (p = 0.001) and low lactic acid (p = 0.003) in the combined sample (n = 53). The present study identified deviated plasma metabolite levels associated with oxidative stress and mitochondrial dysfunction in individuals with ASD.

Altered Metabolites in the Plasma of Autism Spectrum Disorder: A Capillary Electrophoresis Time-of-Flight Mass Spectroscopy Study

PubMed Central

Kuwabara, Hitoshi; Yamasue, Hidenori; Koike, Shinsuke; Inoue, Hideyuki; Kawakubo, Yuki; Kuroda, Miho; Takano, Yosuke; Iwashiro, Norichika; Natsubori, Tatsunobu; Aoki, Yuta; Kano, Yukiko; Kasai, Kiyoto

2013-01-01

Clinical diagnosis and severity of autism spectrum disorders (ASD) are determined by trained clinicians based on clinical evaluations of observed behaviors. As such, this approach is inevitably dependent on the expertise and subjective assessment of those administering the clinical evaluations. There is a need to identify objective biological markers associated with diagnosis or clinical severity of the disorder. To identify novel candidate metabolites as potential biomarkers for ASD, the current study applied capillary electrophoresis time-of-flight mass spectroscopy (CE-TOFMS) for high-throughput profiling of metabolite levels in the plasma of 25 psychotropic-naïve adult males with high-functioning ASD and 28 age-matched typically-developed control subjects. Ten ASD participants and ten age-matched controls were assigned in the first exploration set, while 15 ASD participants and 18 controls were included in the second replication set. By CE-TOFMS analysis, a total of 143 metabolites were detected in the plasma of the first set. Of these, 17 metabolites showed significantly different relative areas between the ASD participants and the controls (p<0.05). Of the 17 metabolites, we consistently found that the ASD participants had significantly high plasma levels of arginine (p = 0.024) and taurine (p = 0.018), and significantly low levels of 5-oxoproline (p<0.001) and lactic acid (p = 0.031) compared with the controls in the second sample set. Further confirmatory analysis using quantification of absolute metabolite concentrations supported the robustness of high arginine (p = 0.001) and low lactic acid (p = 0.003) in the combined sample (n = 53). The present study identified deviated plasma metabolite levels associated with oxidative stress and mitochondrial dysfunction in individuals with ASD. PMID:24058493

Optimized ECR plasma apparatus with varied microwave window thickness

DOEpatents

Berry, Lee A.

1995-01-01

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design.

Analytical Comparison of In Vitro-Spiked Human Serum and Plasma for PCR-Based Detection of Aspergillus fumigatus DNA: a Study by the European Aspergillus PCR Initiative

PubMed Central

Mengoli, Carlo; Springer, Jan; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Klingspor, Lena; Lagrou, Katrien; Melchers, Willem J. G.; Morton, C. Oliver; Barnes, Rosemary A.; Donnelly, J. Peter; White, P. Lewis

2015-01-01

The use of serum or plasma for Aspergillus PCR testing facilitates automated and standardized technology. Recommendations for serum testing are available, and while serum and plasma are regularly considered interchangeable for use in fungal diagnostics, differences in galactomannan enzyme immunoassay (GM-EIA) performance have been reported and are attributed to clot formation. Therefore, it is important to assess plasma PCR testing to determine if previous recommendations for serum are applicable and also to compare analytical performance with that of serum PCR. Molecular methods testing serum and plasma were compared through multicenter distribution of quality control panels, with additional studies to investigate the effect of clot formation and blood fractionation on DNA availability. Analytical sensitivity and time to positivity (TTP) were compared, and a regression analysis was performed to identify variables that enhanced plasma PCR performance. When testing plasma, sample volume, preextraction-to-postextraction volume ratio, PCR volume, duplicate testing, and the use of an internal control for PCR were positively associated with performance. When whole-blood samples were spiked and then fractionated, the analytical sensitivity and TTP were superior when testing plasma. Centrifugation had no effect on DNA availability, whereas the presence of clot material significantly lowered the concentration (P = 0.028). Technically, there are no major differences in the molecular processing of serum and plasma, but the formation of clot material potentially reduces available DNA in serum. During disease, Aspergillus DNA burdens in blood are often at the limits of PCR performance. Using plasma might improve performance while maintaining the methodological simplicity of serum testing. PMID:26085614

Analytical Comparison of In Vitro-Spiked Human Serum and Plasma for PCR-Based Detection of Aspergillus fumigatus DNA: a Study by the European Aspergillus PCR Initiative.

PubMed

Loeffler, Juergen; Mengoli, Carlo; Springer, Jan; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Klingspor, Lena; Lagrou, Katrien; Melchers, Willem J G; Morton, C Oliver; Barnes, Rosemary A; Donnelly, J Peter; White, P Lewis

2015-09-01

The use of serum or plasma for Aspergillus PCR testing facilitates automated and standardized technology. Recommendations for serum testing are available, and while serum and plasma are regularly considered interchangeable for use in fungal diagnostics, differences in galactomannan enzyme immunoassay (GM-EIA) performance have been reported and are attributed to clot formation. Therefore, it is important to assess plasma PCR testing to determine if previous recommendations for serum are applicable and also to compare analytical performance with that of serum PCR. Molecular methods testing serum and plasma were compared through multicenter distribution of quality control panels, with additional studies to investigate the effect of clot formation and blood fractionation on DNA availability. Analytical sensitivity and time to positivity (TTP) were compared, and a regression analysis was performed to identify variables that enhanced plasma PCR performance. When testing plasma, sample volume, preextraction-to-postextraction volume ratio, PCR volume, duplicate testing, and the use of an internal control for PCR were positively associated with performance. When whole-blood samples were spiked and then fractionated, the analytical sensitivity and TTP were superior when testing plasma. Centrifugation had no effect on DNA availability, whereas the presence of clot material significantly lowered the concentration (P = 0.028). Technically, there are no major differences in the molecular processing of serum and plasma, but the formation of clot material potentially reduces available DNA in serum. During disease, Aspergillus DNA burdens in blood are often at the limits of PCR performance. Using plasma might improve performance while maintaining the methodological simplicity of serum testing. Copyright © 2015 Loeffler et al.

Toroidal plasma response based ELM control coil design for EU DEMO

NASA Astrophysics Data System (ADS)

Zhou, Lina; Liu, Yueqiang; Wenninger, Ronald; Liu, Yue; Wang, Shuo; Yang, Xu

2018-07-01

Magnetic coil design study is carried out, for the purpose of mitigating or suppressing the edge localized modes (ELMs) in a EU DEMO reference scenario. The coil design, including both the coil geometry and the coil current requirement, is based on criteria derived from the linear, full toroidal plasma response computed by the MARS-F code (Liu et al 2000 Phys. Plasma 7 3681). With a single midplane row of coils, a coil size covering about 30°–50° poloidal angle of the torus is found to be optimal for ELM control using the n  >  2 resonant magnetic perturbation (RMP) field (n is the toroidal mode number). For off-midplane coils, the coils’ poloidal location, as well as the relative toroidal phase (coil phasing) between the upper and lower rows of coils, also sensitively affects the ELM control according to the specified criteria. Assuming that the optimal coil phasing can always be straightforwardly implemented, following a simple analytic model derived from toroidal computations, it is better to place the two off-midplane rows of coils near the midplane, in order to maximize the resonant field amplitude and to have larger effects on ELMs. With the same coil current, the ex-vessel coils can be made as effective as the in-vessel coils, at the expense of increasing the ex-vessel coils’ size. This is however possible only for low-n (n  =  1–3) RMP fields. With these low-n fields, and assuming 300 kAt maximal coil current, the computed plasma displacement near the X-point can meet the 10 mm level, which we use as the conservative indicator for achieving ELM mitigation in EU DEMO. The risk of partial control coil failure in EU DEMO is also assessed based on toroidal modeling, indicating that the large n  =  1 sideband due to coil failure may need to be corrected, if the nominal n  >  1 coil configurations are used for ELM control in EU DEMO.

Quality Control of Next-generation Sequencing-based In vitro Diagnostic Test for Onco-relevant Mutations Using Multiplex Reference Materials in Plasma.

PubMed

Liu, Donglai; Zhou, Haiwei; Shi, Dawei; Shen, Shu; Tian, Yabin; Wang, Lin; Lou, Jiatao; Cong, Rong; Lu, Juan; Zhang, Henghui; Zhao, Meiru; Zhu, Shida; Cao, Zhisheng; Jin, Ruilin; Wang, Yin; Zhang, Xiaoni; Yang, Guohua; Wang, Youchun; Zhang, Chuntao

2018-01-01

Background: Widespread clinical implementation of next-generation sequencing (NGS)-based cancer in vitro diagnostic tests (IVDs) highlighted the urgency to establish reference materials which could provide full control of the process from nucleic acid extraction to test report generation. The formalin-fixed, paraffin-embedded (FFPE) tissue and blood plasma containing circulating tumor deoxyribonucleic acid (ctDNA) were mostly used for clinically detecting onco-relevant mutations. Methods: We respectively developed multiplex FFPE and plasma reference materials covering three clinically onco-relevant mutations within the epidermal growth factor receptor ( EGFR ) gene at serial allelic frequencies. All reference materials were quantified and validated via droplet digital polymerase chain reaction (ddPCR), and then were distributed to eight domestic manufacturers for the collaborative evaluation of the performance of several domestic NGS-based cancer IVDs covering four major NGS platforms (NextSeq, HiSeq, Ion Proton and BGISEQ). Results: All expected mutations except one at extremely low allelic frequencies were detected, despite some differences in coefficient of variation (CV) which increased with the decrease of allelic frequency (CVs ranging from 18% to 106%). It was worth noting that the CV value seemed to correlate with a particular mutation as well. The repeatability of determination of different mutations was L858R>T790M>19del. Conclusions: The results indicated our reference materials would be pivotal for quality control of NGS-based cancer IVDs and would guide the further development of reference materials covering more onco-relevant mutations.

Thermomagnetic burn control for magnetic fusion reactor

DOEpatents

Rawls, J.M.; Peuron, A.U.

1980-07-01

Apparatus is provided for controlling the plasma energy production rate of a magnetic-confinement fusion reactor, by controlling the magnetic field ripple. The apparatus includes a group of shield sectors formed of ferromagnetic material which has a temperature-dependent saturation magnetization, with each shield lying between the plasma and a toroidal field coil. A mechanism for controlling the temperature of the magnetic shields, as by controlling the flow of cooling water therethrough, thereby controls the saturation magnetization of the shields and therefore the amount of ripple in the magnetic field that confines the plasma, to thereby control the amount of heat loss from the plasma. This heat loss in turn determines the plasma state and thus the rate of energy production.

The interplay between biological and physical scenarios of bacterial death induced by non-thermal plasma.

PubMed

Lunov, Oleg; Zablotskii, Vitalii; Churpita, Olexander; Jäger, Ales; Polívka, Leoš; Syková, Eva; Dejneka, Alexandr; Kubinová, Šárka

2016-03-01

Direct interactions of plasma matter with living cells and tissues can dramatically affect their functionality, initiating many important effects from cancer elimination to bacteria deactivation. However, the physical mechanisms and biochemical pathways underlying the effects of non-thermal plasma on bacteria and cell fate have still not been fully explored. Here, we report on the molecular mechanisms of non-thermal plasma-induced bacteria inactivation in both Gram-positive and Gram-negative strains. We demonstrate that depending on the exposure time plasma induces either direct physical destruction of bacteria or triggers programmed cell death (PCD) that exhibits characteristic features of apoptosis. The interplay between physical disruption and PCD is on the one hand driven by physical plasma parameters, and on the other hand by biological and physical properties of bacteria. The explored possibilities of the tuneable bacteria deactivation provide a basis for the development of advanced plasma-based therapies. To a great extent, our study opens new possibilities for controlled non-thermal plasma interactions with living systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conformal doping of topographic silicon structures using a radial line slot antenna plasma source

NASA Astrophysics Data System (ADS)

Ueda, Hirokazu; Ventzek, Peter L. G.; Oka, Masahiro; Horigome, Masahiro; Kobayashi, Yuuki; Sugimoto, Yasuhiro; Nozawa, Toshihisa; Kawakami, Satoru

2014-06-01

Fin extension doping for 10 nm front end of line technology requires ultra-shallow high dose conformal doping. In this paper, we demonstrate a new radial line slot antenna plasma source based doping process that meets these requirements. Critical to reaching true conformality while maintaining fin integrity is that the ion energy be low and controllable, while the dose absorption is self-limited. The saturated dopant later is rendered conformal by concurrent amorphization and dopant containing capping layer deposition followed by stabilization anneal. Dopant segregation assists in driving dopants from the capping layer into the sub silicon surface. Very high resolution transmission electron microscopy-Energy Dispersive X-ray spectroscopy, used to prove true conformality, was achieved. We demonstrate these results using an n-type arsenic based plasma doping process on 10 to 40 nm high aspect ratio fins structures. The results are discussed in terms of the different types of clusters that form during the plasma doping process.

Reactive ion etching of indium-tin oxide films by CCl4-based Inductivity Coupled Plasma

NASA Astrophysics Data System (ADS)

Juneja, Sucheta; Poletayev, Sergey D.; Fomchenkov, Sergey; Khonina, Svetlana N.; Skidanov, Roman V.; Kazanskiy, Nikolay L.

2016-08-01

Indium tin oxide (ITO) films have been a subject of extensive studies in fabrication of micro-electronic devices for opto-electronic applications ranging from anti-reflection coatings to transparent contacts in photovoltaic devices. In this paper, a new and effective way of reactive ion etching of a conducting indium-tin oxide (ITO) film with Carbon tetrachloride (CCl4) has been investigated. CCl4 plasma containing an addition of gases mixture of dissociated argon and oxygen were used. Oxygen is added to increase the etchant percentage whereas argon was used for stabilization of plasma. The etching characteristics obtained with these gaseous mixtures were explained based on plasma etch chemistry and etching regime of ITO films. An etch rate as high as ∼20 nm/min can be achieved with a controlled process parameter such as power density, total flow rate, composition of reactive gases gas and pressure. Our Investigation represents some of the extensive work in this area.

Trains of electron micro-bunches in plasma wake-field acceleration

NASA Astrophysics Data System (ADS)

Lécz, Zsolt; Andreev, Alexander; Konoplev, Ivan; Seryi, Andrei; Smith, Jonathan

2018-07-01

Plasma-based charged particle accelerators have been intensively investigated in the past three decades due to their capability to open up new horizons in accelerator science and particle physics yielding electric field accelerating gradient more than three orders of magnitudes higher than in conventional devices. At the current stage the most advanced and reliable mechanism for accelerating electrons is based on the propagation of an intense laser pulse or a relativistic electron beam in a low density gaseous target. In this paper we concentrate on the electron beam-driven plasma wake-field acceleration and demonstrate using 3D PiC simulations that a train of electron micro-bunches with ∼10 fs period can be generated behind the driving beam propagating in a density down-ramp. We will discuss the conditions and properties of the micro-bunches generated aiming at understanding and study of multi-bunch mechanism of injection. It is show that the periodicity and duration of micro-bunches can be controlled by adjusting the plasma density gradient and driving beam charge.

A randomized controlled trial oftransfusion-related acute lung injury: is plasma from multiparous blood donors dangerous?

PubMed

Palfi, M; Berg, S; Ernerudh, J; Berlin, G

2001-03-01

Transfusion-related acute lung injury (TRALI) and other posttransfusion reactions may be caused by granulocyte and/or HLA antibodies, which are often present in blood from multiparous donors. The purpose of this study was to compare the effects of plasma from multiparous donors with those of plasma from donors with no history of transfusion or pregnancy (control plasma) in a prospective, randomized, double-blind, crossover study. Intensive care patients, judged to need at least 2 units of plasma, were randomly assigned to receive a unit of control plasma and, 4 hours later, a plasma unit from a multiparous donor (> or = 3 live births) or to receive the plasma units in opposite order. The patients were closely monitored, and body temperature, blood pressure, and heart rate were recorded. Blood samples for analysis of blood gases, TNFalpha, IL-1 receptor antagonist, soluble E selectin, and C3d complement factor were collected at least on four occasions (before and after the transfusion of each unit). Transfusion of plasma from multiparous donors was associated with significantly lower oxygen saturation and higher TNFalpha concentrations than transfusion of control plasma. The mean arterial pressure increased significantly after the transfusion of control plasma, whereas plasma from multiparous donors had no effect on it. Five posttransfusion reactions were observed in 100 patients, in four cases after the transfusion of plasma from multiparous donors. Plasma from multiparous blood donors may impair pulmonary function in intensive care unit patients.

Physics-model-based nonlinear actuator trajectory optimization and safety factor profile feedback control for advanced scenario development in DIII-D

DOE PAGES

Barton, Justin E.; Boyer, Mark D.; Shi, Wenyu; ...

2015-07-30

DIII-D experimental results are reported to demonstrate the potential of physics-model-based safety factor profile control for robust and reproducible sustainment of advanced scenarios. In the absence of feedback control, variability in wall conditions and plasma impurities, as well as drifts due to external disturbances, can limit the reproducibility of discharges with simple pre-programmed scenario trajectories. The control architecture utilized is a feedforward + feedback scheme where the feedforward commands are computed off-line and the feedback commands are computed on-line. In this work, firstly a first-principles-driven (FPD), physics-based model of the q profile and normalized beta (β N) dynamics is embeddedmore » into a numerical optimization algorithm to design feedforward actuator trajectories that sheer the plasma through the tokamak operating space to reach a desired stationary target state that is characterized by the achieved q profile and β N. Good agreement between experimental results and simulations demonstrates the accuracy of the models employed for physics-model-based control design. Secondly, a feedback algorithm for q profile control is designed following a FPD approach, and the ability of the controller to achieve and maintain a target q profile evolution is tested in DIII-D high confinement (H-mode) experiments. The controller is shown to be able to effectively control the q profile when β N is relatively close to the target, indicating the need for integrated q profile and β N control to further enhance the ability to achieve robust scenario execution. Furthermore, the ability of an integrated q profile + β N feedback controller to track a desired target is demonstrated through simulation.« less

Analyses of plasma for metabolic and hormonal changes in rats flown aboard Cosmos 2044

NASA Technical Reports Server (NTRS)

Merrill, Alfred H., Jr.; Wang, Elaine; Mullins, Richard E.; Grindeland, Richard E.; Popova, Irina A.

1992-01-01

Plasmas samples from rats flown aboard Cosmos 2044 were analyzed for the levels of key metabolites, electrolytes, enzymes, and hormones. The major differences between the flight group and the synchronous control were elevations in glucose, cholesterol, phosphate, creatinine, blood urea nitrogen, lactate dehydrogenase, and aspartate aminotransferase and decreased levels of thyroxine. Most of these differences were not mimicked by tail suspension of ground-based rats; however, both flight and suspended rats exhibited inhibited testosterone secretion. Corticosterone, immunoreactive growth hormone, and prolactin showed inconsistent differences from the various control groups, suggesting that the levels of these hormones were not due to actual or simulated microgravity.

HIV-1-RNA in seminal plasma correlates with detection of HIV-1-DNA in semen cells, but not with CMV shedding, among MSM on successful antiretroviral regimens.

PubMed

Gantner, Pierre; Assoumou, Lambert; Leruez-Ville, Marianne; David, Ludivine; Suzan-Monti, Marie; Costagliola, Dominique; Rouzioux, Christine; Ghosn, Jade

2016-11-01

Intermittent seminal HIV-RNA detection can occur in MSM despite concomitant plasma virological control on combined ART (cART). We undertook the present study to determine if seminal HIV detection was associated with seminal cytomegalovirus (CMV) detection or detection of HIV-infected cells in semen. Longitudinal semen samples from HIV-1-infected MSM on successful cART enrolled in the EVARIST ANRS EP 49 study were analysed. We first conducted a case-control analysis (ratio 1 : 3) to assess HIV-DNA detection in semen cells in the 20 patients with detectable HIV-RNA in seminal plasma (cases) matched with 60 participants with undetectable HIV-RNA (controls) based on total HIV-DNA load in blood cells. Second, we measured CMV-DNA in all seminal plasma samples. HIV-1-DNA in semen cells was detected on at least one sample visit in 12/20 cases and 11/60 controls. Detection of HIV-RNA in seminal plasma was associated significantly with the detection of HIV-DNA in semen cells [OR, 7.6 (95% CI, 2.1-28.4); P = 0.002] when adjusted on total HIV-DNA in blood cells. CMV-DNA was detected in 107/273 seminal plasma samples with a median value of 3.62 log 10 copies/mL (IQR, 2.83-4.38), yielding a prevalence of 39.2%. Seminal CMV-DNA shedding [OR, 1.5 (95% CI, 0.6-3.6); P = 0.343] was not associated with the risk of detection of HIV-RNA in seminal plasma. The presence of HIV-DNA in semen cells was predictive of HIV-RNA detection, suggesting that viral particles arise through local HIV replication by infected semen cells. Despite virological control, compartmentalization of HIV in the genital tract might act in residual replication and transmission. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Theory and Modeling of Petawatt Laser Pulse Propagation in Low Density Plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadwick, Bradley A.; Kalmykov, S. Y.

Report describing accomplishments in all-optical control of self-injection in laser-plasma accelerators and in developing advanced numerical models of laser-plasma interactions. All-optical approaches to controlling electron self-injection and beam formation in laser-plasma accelerators (LPAs) were explored. It was demonstrated that control over the laser pulse evolution is the key ingredient in the generation of low-background, low-phase-space-volume electron beams. To this end, preserving a smooth laser pulse envelope throughout the acceleration process can be achieved through tuning the phase and amplitude of the incident pulse. A negative frequency chirp compensates the frequency red-shift accumulated due to wake excitation, preventing evolution of themore » pulse into a relativistic optical shock. This reduces the ponderomotive force exerted on quiescent plasma electrons, suppressing expansion of the bubble and continuous injection of background electrons, thereby reducing the charge in the low-energy tail by an order of magnitude. Slowly raising the density in the pulse propagation direction locks electrons in the accelerating phase, boosting their energy, keeping continuous injection at a low level, tripling the brightness of the quasi-monoenergetic component. Additionally, propagating the negatively chirped pulse in a plasma channel suppresses diffraction of the pulse leading edge, further reducing continuous injection. As a side effect, oscillations of the pulse tail may be enhanced, leading to production of low-background, polychromatic electron beams. Such beams, consisting of quasi-monoenergetic components with controllable energy and energy separation, may be useful as drivers of polychromatic x-rays based on Thomson backscattering. These all-optical methods of electron beam quality control are critically important for the development of future compact, high-repetition-rate, GeV-scale LPA using 10 TW-class, ultra-high bandwidth pulses and mm-scale, dense plasmas. These results emphasize that investment into new pulse amplification techniques allowing for ultrahigh frequency bandwidth is as important for the design of future LPA as are the current efforts directed to increasing the pulse energy.« less

Automated standardization technique for an inductively-coupled plasma emission spectrometer

USGS Publications Warehouse

Garbarino, John R.; Taylor, Howard E.

1982-01-01

The manifold assembly subsystem described permits real-time computer-controlled standardization and quality control of a commercial inductively-coupled plasma atomic emission spectrometer. The manifold assembly consists of a branch-structured glass manifold, a series of microcomputer-controlled solenoid valves, and a reservoir for each standard. Automated standardization involves selective actuation of each solenoid valve that permits a specific mixed standard solution to be pumped to the nebulizer of the spectrometer. Quality control is based on the evaluation of results obtained for a mixed standard containing 17 analytes, that is measured periodically with unknown samples. An inaccurate standard evaluation triggers restandardization of the instrument according to a predetermined protocol. Interaction of the computer-controlled manifold assembly hardware with the spectrometer system is outlined. Evaluation of the automated standardization system with respect to reliability, simplicity, flexibility, and efficiency is compared to the manual procedure. ?? 1982.

Invited Article: A novel calibration method for the JET real-time far infrared polarimeter and integration of polarimetry-based line-integrated density measurements for machine protection of a fusion plant.

PubMed

Boboc, A; Bieg, B; Felton, R; Dalley, S; Kravtsov, Yu

2015-09-01

In this paper, we present the work in the implementation of a new calibration for the JET real-time polarimeter based on the complex amplitude ratio technique and a new self-validation mechanism of data. This allowed easy integration of the polarimetry measurements into the JET plasma density control (gas feedback control) and as well as machine protection systems (neutral beam injection heating safety interlocks). The new addition was used successfully during 2014 JET Campaign and is envisaged that will operate routinely from 2015 campaign onwards in any plasma condition (including ITER relevant scenarios). This mode of operation elevated the importance of the polarimetry as a diagnostic tool in the view of future fusion experiments.

Invited Article: A novel calibration method for the JET real-time far infrared polarimeter and integration of polarimetry-based line-integrated density measurements for machine protection of a fusion plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boboc, A., E-mail: Alexandru.Boboc@ccfe.ac.uk; Felton, R.; Dalley, S.

2015-09-15

In this paper, we present the work in the implementation of a new calibration for the JET real-time polarimeter based on the complex amplitude ratio technique and a new self-validation mechanism of data. This allowed easy integration of the polarimetry measurements into the JET plasma density control (gas feedback control) and as well as machine protection systems (neutral beam injection heating safety interlocks). The new addition was used successfully during 2014 JET Campaign and is envisaged that will operate routinely from 2015 campaign onwards in any plasma condition (including ITER relevant scenarios). This mode of operation elevated the importance ofmore » the polarimetry as a diagnostic tool in the view of future fusion experiments.« less

Beam transport and monitoring for laser plasma accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, K.; Sokollik, T.; Tilborg, J. van

The controlled transport and imaging of relativistic electron beams from laser plasma accelerators (LPAs) are critical for their diagnostics and applications. Here we present the design and progress in the implementation of the transport and monitoring system for an undulator based electron beam diagnostic. Miniature permanent-magnet quadrupoles (PMQs) are employed to realize controlled transport of the LPA electron beams, and cavity based electron beam position monitors for non-invasive beam position detection. Also presented is PMQ calibration by using LPA electron beams with broadband energy spectrum. The results show promising performance for both transporting and monitoring. With the proper transport system,more » XUV-photon spectra from THUNDER will provide the momentum distribution of the electron beam with the resolution above what can be achieved by the magnetic spectrometer currently used in the LOASIS facility.« less

Accelerator based fusion reactor

NASA Astrophysics Data System (ADS)

Liu, Keh-Fei; Chao, Alexander Wu

2017-08-01

A feasibility study of fusion reactors based on accelerators is carried out. We consider a novel scheme where a beam from the accelerator hits the target plasma on the resonance of the fusion reaction and establish characteristic criteria for a workable reactor. We consider the reactions d+t\\to n+α,d+{{}3}{{H}\\text{e}}\\to p+α , and p+{{}11}B\\to 3α in this study. The critical temperature of the plasma is determined from overcoming the stopping power of the beam with the fusion energy gain. The needed plasma lifetime is determined from the width of the resonance, the beam velocity and the plasma density. We estimate the critical beam flux by balancing the energy of fusion production against the plasma thermo-energy and the loss due to stopping power for the case of an inert plasma. The product of critical flux and plasma lifetime is independent of plasma density and has a weak dependence on temperature. Even though the critical temperatures for these reactions are lower than those for the thermonuclear reactors, the critical flux is in the range of {{10}22}-{{10}24}~\\text{c}{{\\text{m}}-2}~{{\\text{s}}-1} for the plasma density {ρt}={{10}15}~\\text{c}{{\\text{m}}-3} in the case of an inert plasma. Several approaches to control the growth of the two-stream instability are discussed. We have also considered several scenarios for practical implementation which will require further studies. Finally, we consider the case where the injected beam at the resonance energy maintains the plasma temperature and prolongs its lifetime to reach a steady state. The equations for power balance and particle number conservation are given for this case.

Magnetic Field Effects on Plasma Plumes

NASA Technical Reports Server (NTRS)

Ebersohn, F.; Shebalin, J.; Girimaji, S.; Staack, D.

2012-01-01

Here, we will discuss our numerical studies of plasma jets and loops, of basic interest for plasma propulsion and plasma astrophysics. Space plasma propulsion systems require strong guiding magnetic fields known as magnetic nozzles to control plasma flow and produce thrust. Propulsion methods currently being developed that require magnetic nozzles include the VAriable Specific Impulse Magnetoplasma Rocket (VASIMR) [1] and magnetoplasmadynamic thrusters. Magnetic nozzles are functionally similar to de Laval nozzles, but are inherently more complex due to electromagnetic field interactions. The two crucial physical phenomenon are thrust production and plasma detachment. Thrust production encompasses the energy conversion within the nozzle and momentum transfer to a spacecraft. Plasma detachment through magnetic reconnection addresses the problem of the fluid separating efficiently from the magnetic field lines to produce maximum thrust. Plasma jets similar to those of VASIMR will be studied with particular interest in dual jet configurations, which begin as a plasma loops between two nozzles. This research strives to fulfill a need for computational study of these systems and should culminate with a greater understanding of the crucial physics of magnetic nozzles with dual jet plasma thrusters, as well as astrophysics problems such as magnetic reconnection and dynamics of coronal loops.[2] To study this problem a novel, hybrid kinetic theory and single fluid magnetohydrodynamic (MHD) solver known as the Magneto-Gas Kinetic Method is used.[3] The solver is comprised of a "hydrodynamic" portion based on the Gas Kinetic Method and a "magnetic" portion that accounts for the electromagnetic behaviour of the fluid through source terms based on the resistive MHD equations. This method is being further developed to include additional physics such as the Hall effect. Here, we will discuss the current level of code development, as well as numerical simulation results

Low n-6:n-3 fatty acid ratio, with fish- or flaxseed oil, in a high fat diet improves plasma lipids and beneficially alters tissue fatty acid composition in mice.

PubMed

Riediger, Natalie D; Othman, Rgia; Fitz, Evelyn; Pierce, Grant N; Suh, Miyoung; Moghadasian, Mohammed H

2008-04-01

Health benefits from low n-6:n-3 fatty acid (FA) ratio on cardiovascular risk have been shown. However, the impact of the source of n-3 FAs has not been fully investigated. Our purpose was to investigate cardiovascular benefits of oils with a low ratio of n-6:n-3 FAs, but different sources of n-3 FAs in C57BL/6 mice. Twenty-one mice were divided into 3 groups (n=7) and fed a diet supplemented with either a fish or flaxseed oil-based 'designer oils' with an approximate n-6:n-3 FA ratio of 2/1 or with a safflower-oil-based diet with a ratio of 25/1, for 16 weeks. Plasma lipids and fatty acid profile of the liver tissue were characterized. Compared to baseline, plasma triacylglycerol levels declined (>50%) in all groups by week 4. Plasma cholesterol levels were reduced in both fish and flax groups by 27% and 36%, respectively, as compared to controls at endpoint. The levels of EPA and DHA in liver phospholipids were significantly increased in both fish and flax groups as compared to the control group, with more profound increases in the fish group. Arachidonic acid levels were similarly decreased in the liver tissues from both fish and flax groups as compared to controls. Our data suggest that health benefits may be achieved by lowering dietary n-6:n-3 FA even in a high fat diet medium.

Large inter-individual variation in isoflavone plasma concentration limits use of isoflavone intake data for risk assessment

PubMed Central

van der Velpen, V; Hollman, P C; van Nielen, M; Schouten, E G; Mensink, M; van't Veer, P; Geelen, A

2014-01-01

Background/objectives: Isoflavones are present in soy foods and soy-based supplements. Despite low plasma isoflavone concentrations in the general Western population, concentrations in supplement users exceed those suggested to be beneficial for health in Asian populations, raising concerns for adverse effects. To aid risk assessment, quantification of the relation between isoflavone intake and plasma concentrations is essential. Subjects/methods: Plasma samples were collected from postmenopausal women in three placebo-controlled crossover studies with 8-week periods for supplements (two studies, ~100 mg isoflavones/day, n=88) or 4-week periods for soy foods (one study, ~48 mg isoflavones/day, n=15). Plasma isoflavone concentrations (daidzein, equol, genistein and glycitein) were quantified using high-performance liquid chromatography and electrochemical detection. The association between plasma concentrations and isoflavone intake, equol producer status, intake–producer interaction and background dietary intake was assessed based on the assumption of a log-linear relation. Results: Median plasma total isoflavone concentrations after the soy food and supplement interventions were respectively 2.16 and 3.47 μmol/l for equol producers and 1.30 and 2.39 μmol/l for non-producers. Regression analysis showed that doubling isoflavone intake increased plasma concentrations by 55–62% (±s.e. 1–2%, R2>0.87) for daidzein, genistein, equol (only for producers) and total isoflavones; for glycitein the association was weaker (15±1%, R2=0.48). Adjustments for energy, carbohydrate and fat intake did not affect these estimates. Inter-individual variation, estimated based on repeated measures in one of the studies, was 30–96%. Conclusions: Although the relation between isoflavone intake and plasma concentrations was adequately quantified, the use of isoflavone intake data for risk assessment needs caution due to large inter-individual variation in plasma concentrations. PMID:24939433

An Industry Viewpoint on Electron Energy Distribution Function Control

NASA Astrophysics Data System (ADS)

Ventzek, Peter

2011-10-01

It is trite to note that plasmas play a key role in industrial technology. Lighting, laser, film coating and now medical technology require plasma science for their sustenance. One field stands out by virtue of its economic girth and impact. Semiconductor manufacturing and process science enabling its decades of innovation owe significant debt to progress in low temperature plasma science. Today, technology requires atomic level control from plasmas. Mere layers of atoms delineate good and bad device performance. While plasma sources meet nanoscale specifications over 100s cm scale dimensions, achieving atomic level control from plasmas is hindered by the absence of direct control of species velocity distribution functions. EEDF control translates to precise control of species flux and velocities at surfaces adjacent to the plasma. Electron energy distribution function (eedf) control is a challenge that, if successfully met, will have a huge impact on nanoscale device manufacturing. This lunchtime talk will attempt to provide context to the research advances presented at this Workshop. Touched on will be areas of new opportunity and the risks associated with missing these opportunities.

Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

PubMed

Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

2007-02-01

Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for plasma triglyceride concentrations compared to the control (-53% and -65%, respectively) and ferulic acid (-47% and -60%, respectively) diets. Hamsters fed the control and ferulic acid diets had significantly higher plasma vitamin E concentrations compared to the RBO (201% and 161%, respectively) and oryzanol (548% and 462%, respectively) diets; the ferulic acid and oryzanol diets had significantly lower plasma lipid hydroperoxide levels than the control (-57% and -46%, respectively) diet. The oryzanol-fed hamsters excreted significantly more coprostenol and cholesterol in their feces than the ferulic acid (127% and 120%, respectively) diet. The control diet had significantly greater aortic TC and FC accumulation compared to the RBO (115% and 89%, respectively), ferulic acid (48% and 58%, respectively) and the oryzanol (74% and 70%, respectively) diets. However, only the RBO and oryzanol diets had significantly lower aortic cholesterol ester accumulation compared to the control (-73% and -46%, respectively) diet. The present study suggests that at equal dietary levels, oryzanol has a greater effect on lowering plasma non-HDL-C levels and raising plasma HDL-C than ferulic acid, possibly through a greater extent to increase fecal excretion of cholesterol and its metabolites. However, ferulic acid may have a greater antioxidant capacity via its ability to maintain serum vitamin E levels compared to RBO and oryzanol. Thus, both oryzanol and ferulic acid may exert similar antiatherogenic properties, but through different mechanisms.

Control of impurities in toroidal plasma devices

DOEpatents

Ohkawa, Tihiro

1980-01-01

A method and apparatus for plasma impurity control in closed flux plasma systems such as Tokamak reactors is disclosed. Local axisymmetrical injection of hydrogen gas is employed to reverse the normally inward flow of impurities into the plasma.

Reduced-order model based feedback control of the modified Hasegawa-Wakatani model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goumiri, I. R.; Rowley, C. W.; Ma, Z.

2013-04-15

In this work, the development of model-based feedback control that stabilizes an unstable equilibrium is obtained for the Modified Hasegawa-Wakatani (MHW) equations, a classic model in plasma turbulence. First, a balanced truncation (a model reduction technique that has proven successful in flow control design problems) is applied to obtain a low dimensional model of the linearized MHW equation. Then, a model-based feedback controller is designed for the reduced order model using linear quadratic regulators. Finally, a linear quadratic Gaussian controller which is more resistant to disturbances is deduced. The controller is applied on the non-reduced, nonlinear MHW equations to stabilizemore » the equilibrium and suppress the transition to drift-wave induced turbulence.« less

KRAS mutations in blood circulating cell-free DNA: a pancreatic cancer case-control

PubMed Central

Le Calvez-Kelm, Florence; Foll, Matthieu; Wozniak, Magdalena B.; Delhomme, Tiffany M.; Durand, Geoffroy; Chopard, Priscilia; Pertesi, Maroulio; Fabianova, Eleonora; Adamcakova, Zora; Holcatova, Ivana; Foretova, Lenka; Janout, Vladimir; Vallee, Maxime P.; Rinaldi, Sabina; Brennan, Paul; McKay, James D.; Byrnes, Graham B.; Scelo, Ghislaine

2016-01-01

The utility of KRAS mutations in plasma circulating cell-free DNA (cfDNA) samples as non-invasive biomarkers for the detection of pancreatic cancer has never been evaluated in a large case-control series. We applied a KRAS amplicon-based deep sequencing strategy combined with analytical pipeline specifically designed for the detection of low-abundance mutations to screen plasma samples of 437 pancreatic cancer cases, 141 chronic pancreatitis subjects, and 394 healthy controls. We detected mutations in 21.1% (N=92) of cases, of whom 82 (89.1%) carried at least one mutation at hotspot codons 12, 13 or 61, with mutant allelic fractions from 0.08% to 79%. Advanced stages were associated with an increased proportion of detection, with KRAS cfDNA mutations detected in 10.3%, 17,5% and 33.3% of cases with local, regional and systemic stages, respectively. We also detected KRAS cfDNA mutations in 3.7% (N=14) of healthy controls and in 4.3% (N=6) of subjects with chronic pancreatitis, but at significantly lower allelic fractions than in cases. Combining cfDNA KRAS mutations and CA19-9 plasma levels on a limited set of case-control samples did not improve the overall performance of the biomarkers as compared to CA19-9 alone. Whether the limited sensitivity and specificity observed in our series of KRAS mutations in plasma cfDNA as biomarkers for pancreatic cancer detection are attributable to methodological limitations or to the biology of cfDNA should be further assessed in large case-control series. PMID:27705932

Optimized ECR plasma apparatus with varied microwave window thickness

DOEpatents

Berry, L.A.

1995-11-14

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figs.

Hydrodynamic evolution of plasma waveguides for soft-x-ray amplifiers

NASA Astrophysics Data System (ADS)

Oliva, Eduardo; Depresseux, Adrien; Cotelo, Manuel; Lifschitz, Agustín; Tissandier, Fabien; Gautier, Julien; Maynard, Gilles; Velarde, Pedro; Sebban, Stéphane

2018-02-01

High-density, collisionally pumped plasma-based soft-x-ray lasers have recently delivered hundreds of femtosecond pulses, breaking the longstanding barrier of one picosecond. To pump these amplifiers an intense infrared pulse must propagate focused throughout all the length of the amplifier, which spans several Rayleigh lengths. However, strong nonlinear effects hinder the propagation of the laser beam. The use of a plasma waveguide allows us to overcome these drawbacks provided the hydrodynamic processes that dominate the creation and posterior evolution of the waveguide are controlled and optimized. In this paper we present experimental measurements of the radial density profile and transmittance of such waveguide, and we compare them with numerical calculations using hydrodynamic and particle-in-cell codes. Controlling the properties (electron density value and radial gradient) of the waveguide with the help of numerical codes promises the delivery of ultrashort (tens of femtoseconds), coherent soft-x-ray pulses.

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device.

PubMed

Srivastava, P K; Singh, S K; Sanyasi, A K; Awasthi, L M; Mattoo, S K

2016-07-01

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, P. K., E-mail: pkumar@ipr.res.in; Singh, S. K.; Sanyasi, A. K.

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltagemore » protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.« less

Status of National Spherical Torus Experiment Liquid Lithium Divertor

NASA Astrophysics Data System (ADS)

Kugel, H. W.; Viola, M.; Ellis, R.; Bell, M.; Gerhardt, S.; Kaita, R.; Kallman, J.; Majeski, R.; Mansfield, D.; Roquemore, A. L.; Schneider, H.; Timberlake, J.; Zakharov, L.; Nygren, R. E.; Allain, J. P.; Maingi, R.; Soukhanovskii, V.

2009-11-01

Recent NSTX high power divertor experiments have shown significant and recurring benefits of solid lithium coatings on plasma facing components to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. The next step in this work is the 2009 installation of a Liquid Lithium Divertor (LLD). The 20 cm wide LLD located on the lower outer divertor, consists of four, 80 degree sections; each section is separated by a row of graphite diagnostic tiles. The temperature controlled LLD structure consists of a 0.01cm layer of vacuum flame-sprayed, 50 percent porous molybdenum, on top of 0.02 cm, 316-SS brazed to a 1.9 cm Cu base. The physics design of the LLD encompasses the desired plasma requirements, the experimental capabilities and conditions, power handling, radial location, pumping capability, operating temperature, lithium filling, MHD forces, and diagnostics for control and characterization.

Pulsed Plasma Thrusters for Small Spacecraft Attitude Control

NASA Technical Reports Server (NTRS)

McGuire, Melissa L.; Myers, Roger M.

1996-01-01

Pulsed plasma thrusters (PPT's) are a new option for attitude control of a small spacecraft and may result in reduced attitude control system (ACS) mass and cost. The primary purpose of an ACS is to orient the spacecraft configuration to the desired accuracy in inertial space. The ACS functions for which the PPT system will be analyzed include disturbance torque compensation and slewing maneuvers such as sun acquisition for which the small impulse bit and high specific impulse of the PPT offers unique advantages. The NASA Lewis Reserach Center (LeRC) currently has a contracted flight PPT system development program in place with Olin Aerospace and a delivery date of October 1997. The PPT system in this study are based upon the work being done under the NASA LeRC program. Analysis of the use of PPT's for ACS showed that the replacement of the standard momentum wheels and torque rods systems with a PTT system to perform the altitude control maneuvers on a small low Earth orbiting spacecraft reduced the ACS mass by 50 to 75 percent with no increase in required power level over comparable wheel-based systems.

Thermomagnetic burn control for magnetic fusion reactor

DOEpatents

Rawls, John M.; Peuron, Unto A.

1982-01-01

Apparatus is provided for controlling the plasma energy production rate of a magnetic-confinement fusion reactor, by controlling the magnetic field ripple. The apparatus includes a group of shield sectors (30a, 30b, etc.) formed of ferromagnetic material which has a temperature-dependent saturation magnetization, with each shield lying between the plasma (12) and a toroidal field coil (18). A mechanism (60) for controlling the temperature of the magnetic shields, as by controlling the flow of cooling water therethrough, thereby controls the saturation magnetization of the shields and therefore the amount of ripple in the magnetic field that confines the plasma, to thereby control the amount of heat loss from the plasma. This heat loss in turn determines the plasma state and thus the rate of energy production.

Method for the rapid synthesis of large quantities of metal oxide nanowires at low temperatures

DOEpatents

Sunkara, Mahendra Kumar [Louisville, KY; Vaddiraju, Sreeram [Mountain View, CA; Mozetic, Miran [Ljubljan, SI; Cvelbar, Uros [Idrija, SI

2009-09-22

A process for the rapid synthesis of metal oxide nanoparticles at low temperatures and methods which facilitate the fabrication of long metal oxide nanowires. The method is based on treatment of metals with oxygen plasma. Using oxygen plasma at low temperatures allows for rapid growth unlike other synthesis methods where nanomaterials take a long time to grow. Density of neutral oxygen atoms in plasma is a controlling factor for the yield of nanowires. The oxygen atom density window differs for different materials. By selecting the optimal oxygen atom density for various materials the yield can be maximized for nanowire synthesis of the metal.

Reconstruction of magnetic configurations in W7-X using artificial neural networks

NASA Astrophysics Data System (ADS)

Böckenhoff, Daniel; Blatzheim, Marko; Hölbe, Hauke; Niemann, Holger; Pisano, Fabio; Labahn, Roger; Pedersen, Thomas Sunn; The W7-X Team

2018-05-01

It is demonstrated that artificial neural networks can be used to accurately and efficiently predict details of the magnetic topology at the plasma edge of the Wendelstein 7-X stellarator, based on simulated as well as measured heat load patterns onto plasma-facing components observed with infrared cameras. The connection between heat load patterns and the magnetic topology is a challenging regression problem, but one that suits artificial neural networks well. The use of a neural network makes it feasible to analyze and control the plasma exhaust in real-time, an important goal for Wendelstein 7-X, and for magnetic confinement fusion research in general.

Nanocarbon materials fabricated using plasmas

NASA Astrophysics Data System (ADS)

Hatakeyama, Rikizo

2017-12-01

Since the discovery of fullerenes more than three decades ago, new kinds of nanoscale materials of carbon allotropes called "nanocarbons" have so far been discovered or synthesized at successive intervals as cases such as carbon nanotubes, carbon nanohorns, graphene, carbon nanowalls, and a carbon nanobelt, while nanodiamonds were actually discovered before then. Their attractively excellent mechanical, physical, and chemical properties have driven researchers to continuously create one of the hottest frontiers in materials science and technology. While plasma states have often been involved in their discovery, on the other hand, plasma-based approaches to this exciting field originally hold promising and enormous potentials for advancing and expanding industrial/biomedical applications of nanocarbons of great diversity. This article provides an extensive overview on plasma-fabricated nanocarbon materials, where the term "fabrication" is defined as synthesis, functionalization, and assembly of devices to cover a wide range of issues associated with the step-by-step plasma processes. Specific attention has been paid to the comparative examination between plasma-based and non-plasma methods for fabricating the nanocarobons with an emphasis on the advantages of plasma processing, such as low-temperature/large-scale fabrication and diversity-carrying structure controllability. The review ends with current challenges and prospects including a ripple effect of the nanocarbon studies on the development of related novel nanomaterials such as transition metal dichalcogenides. It contains not only the latest progress in the field for cutting-edge scientists and engineers, but also the introductory guidance to non-specialists such as lower-class graduate students.

Analysis of GaN Damage Induced by Cl2/SiCl4/Ar Plasma

NASA Astrophysics Data System (ADS)

Minami, Masaki; Tomiya, Shigetaka; Ishikawa, Kenji; Matsumoto, Ryosuke; Chen, Shang; Fukasawa, Masanaga; Uesawa, Fumikatsu; Sekine, Makoto; Hori, Masaru; Tatsumi, Tetsuya

2011-08-01

GaN-based optical devices are fabricated using a GaN/InGaN/GaN sandwiched structure. The effect of radicals, ions, and UV light on the GaN optical properties during Cl2/SiCl4/Ar plasma etching was evaluated using photoluminescence (PL) analysis. The samples were exposed to plasma (radicals, ions, and UV light) using an inductively coupled plasma (ICP) etching system and a plasma ion beam apparatus that can separate the effects of UV and ions both with and without covering the SiO2 window on the surface. Etching damage in an InGaN single quantum well (SQW) was formed by exposing the sample to plasma. The damage, which decreases PL emission intensity, was generated not only by ion beam irradiation but also by UV light irradiation. PL intensity decreased when the thickness of the upper GaN layer was etched to less than 60 nm. In addition, simultaneous irradiation of UV light and ions slightly increased the degree of damage. There seems to be a synergistic effect between the UV light and the ions. For high-quality GaN-based optoelectronics and power devices, UV light must be controlled during etching processes in addition to the etching profile, selectivity, and ion bombardment damage.

Addressing Theory and Performance Enhancements for the Independent Sustain and Address AC Plasma Display

NASA Astrophysics Data System (ADS)

Warren, Kevin Wilson

The Independent Sustain and Address (ISA) AC plasma panel is a flat, flicker-free, gas discharge type of display device. This display technology promises to reduce both the cost of manufacturing and operation of AC plasma displays. The ISA technology uses a vastly different mechanism to change the state of the display pixels than the standard AC plasma technology. This addressing mechanism is an exploitation of some of the natural characteristics associated with the plasma that can form during strong gas discharges. This thesis presents detailed data from experiments that were designed to evaluate and test the effectiveness of this mechanism. Through these experiments, the theory that the addressing methodology is based upon is developed and evaluated. These experiments show that the address margin windows for this technology are very large, minimally two to three times larger than the address margins for the standard XY AC plasma addressing techniques. New capabilities are also described, such as global brightness control for the ISA technology and a technique for increasing the addressing rate. These advances were designed into working prototypes and transferred to industry where there are currently commercial products available based upon these advances. A technique for implementing gray scale using some of these advances is also proposed.

Quantum cascade laser based monitoring of CF{sub 2} radical concentration as a diagnostic tool of dielectric etching plasma processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hübner, M.; Lang, N.; Röpcke, J.

2015-01-19

Dielectric etching plasma processes for modern interlevel dielectrics become more and more complex by the introduction of new ultra low-k dielectrics. One challenge is the minimization of sidewall damage, while etching ultra low-k porous SiCOH by fluorocarbon plasmas. The optimization of this process requires a deeper understanding of the concentration of the CF{sub 2} radical, which acts as precursor in the polymerization of the etch sample surfaces. In an industrial dielectric etching plasma reactor, the CF{sub 2} radical was measured in situ using a continuous wave quantum cascade laser (cw-QCL) around 1106.2 cm{sup −1}. We measured Doppler-resolved ro-vibrational absorption lines andmore » determined absolute densities using transitions in the ν{sub 3} fundamental band of CF{sub 2} with the aid of an improved simulation of the line strengths. We found that the CF{sub 2} radical concentration during the etching plasma process directly correlates to the layer structure of the etched wafer. Hence, this correlation can serve as a diagnostic tool of dielectric etching plasma processes. Applying QCL based absorption spectroscopy opens up the way for advanced process monitoring and etching controlling in semiconductor manufacturing.« less

Fluid and electrolyte homeostasis in space - A primate model to look at mechanisms

NASA Technical Reports Server (NTRS)

Moore-Ede, M. C.; Churchill, S. E.; Leach, C. S.; Sulzman, F. M.; Fuller, C. A.; Kass, D.

1982-01-01

To elucidate the physiological mechanisms involved in the cardiovascular and renal responses to spaceflight, a ground-based primate model has been developed which uses lower body positive pressure (LBPP) to simulate the chronic central vascular expansion associated with weightlessnes. Four male squirrel monkeys with chronically implanted arterial and venous catheters and the capacity for continuous urine collection were subjected to LBPP for 4 days. Onset of LBPP resulted in an immediate diuresis, natriuresis and kaliuresis and a significant fall in plasma aldosterone and potassium levels. By day 2 the level of natriuresis had decreased by half, while potassium excretion and plasma aldosterone values had returned to control levels despite the persistence of a significantly reduced plasma potassium concentration. It is concluded that the low plasma potassium level appears not to stimulate a compensatory fall in plasma aldosterone because of the simultaneous presence of body volume contraction acting to raise aldosterone levels.

Understanding Turbulence using Active and Passive Multipoint Measurements in Laboratory Magnetospheres

NASA Astrophysics Data System (ADS)

Mauel, M. E.; Abler, M. C.; Qian, T. M.; Saperstein, A.; Yan, J. R.

2017-10-01

In a laboratory magnetosphere, plasma is confined by a strong dipole magnet, and interchange and entropy mode turbulence can be studied and controlled in near steady-state conditions. Turbulence is dominated by long wavelength modes exhibiting chaotic dynamics, intermitency, and an inverse spectral cascade. Here, we summarize recent results: (i) high-resolution measurement of the frequency-wavenumber power spectrum using Capon's ``maximum likelihood method'', and (ii) direct measurement of the nonlinear coupling of interchange/entropy modes in a turbulent plasma through driven current injection at multiple locations and frequencies. These observations well-characterize plasma turbulence over a broad band of wavelengths and frequencies. Finally, we also discuss the application of these techniques to space-based experiments and observations aimed to reveal the nature of heliospheric and magnetospheric plasma turbulence. Supported by NSF-DOE Partnership in Plasma Science Grant DE-FG02-00ER54585.

Insights into gold-catalyzed plasma-assisted CVD growth of silicon nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wanghua, E-mail: wanghua.chen@polytechnique.edu; Roca i Cabarrocas, Pere

2016-07-25

Understanding and controlling effectively the behavior of metal catalyst droplets during the Vapor-Liquid-Solid growth of nanowires are crucial for their applications. In this work, silicon nanowires are produced by plasma-assisted Chemical Vapor Deposition using gold as a catalyst. The influence of hydrogen plasma on nanowire growth is investigated experimentally and theoretically. Interestingly, in contrast to conventional chemical vapor deposition, the growth rate of silicon nanowires shows a decrease as a function of their diameters, which is consistent with the incorporation of silicon via sidewall diffusion. We show that Ostwald ripening of catalyst droplets during nanowire growth is inhibited in themore » presence of a hydrogen plasma. However, when the plasma is off, the diffusion of Au atoms on the nanowire sidewall can take place. Based on this observation, we have developed a convenient method to grow silicon nanotrees.« less

Laser-plasma interactions in magnetized environment

NASA Astrophysics Data System (ADS)

Shi, Yuan; Qin, Hong; Fisch, Nathaniel J.

2018-05-01

Propagation and scattering of lasers present new phenomena and applications when the plasma medium becomes strongly magnetized. With mega-Gauss magnetic fields, scattering of optical lasers already becomes manifestly anisotropic. Special angles exist where coherent laser scattering is either enhanced or suppressed, as we demonstrate using a cold-fluid model. Consequently, by aiming laser beams at special angles, one may be able to optimize laser-plasma coupling in magnetized implosion experiments. In addition, magnetized scattering can be exploited to improve the performance of plasma-based laser pulse amplifiers. Using the magnetic field as an extra control variable, it is possible to produce optical pulses of higher intensity, as well as compress UV and soft x-ray pulses beyond the reach of other methods. In even stronger giga-Gauss magnetic fields, laser-plasma interaction enters a relativistic-quantum regime. Using quantum electrodynamics, we compute a modified wave dispersion relation, which enables correct interpretation of Faraday rotation measurements of strong magnetic fields.

Lipid profile in oral submucous fibrosis.

PubMed

Mehrotra, Ravi; Pandya, Shruti; Chaudhary, Ajay Kumar; Singh, Himanshu Pratap; Jaiswal, Ritesh Kumar; Singh, Mangal; Gupta, S C; Singh, Mamta

2009-07-24

Changes in lipid profile have long been associated with malignancies as lipids play a key role in maintenance of cell integrity. This study evaluated the alterations in extended lipid profile in untreated patients of oral submucous fibrosis (OSMF) and studied the correlation between lipid levels with tobacco consumption. In this hospital-based study, 65 clinically diagnosed and histopathologically proven patients of OSMF and 42 age and sex matched controls were studied. In these samples serum lipids including: (i) Total cholesterol, (ii) LDL cholesterol (LDLC), (iii) HDL cholesterol (HDLC) (iv) VLDL cholesterol (VLDLC) (v) triglycerides (vi) Apo-A1 (viii) Apo-B and (viii) LPa were analyzed. A significant decrease in plasma total cholesterol, HDLC and Apo-A1 was observed in patients with OSMF as compared to the controls. Thus an inverse relationship between plasma lipid levels and patients was found in OSMF. The lower levels of plasma cholesterol and other lipid constituents in patients might be due to their increased utilization. The findings strongly warrant an in-depth study of alterations in plasma lipid profile in patients with oral precancerous conditions.

Pathogen inactivation treatment of plasma and platelet concentrates and their predicted functionality in massive transfusion protocols.

PubMed

Arbaeen, Ahmad F; Schubert, Peter; Serrano, Katherine; Carter, Cedric J; Culibrk, Brankica; Devine, Dana V

2017-05-01

Trauma transfusion packages for hemorrhage control consist of red blood cells, plasma, and platelets at a set ratio. Although pathogen reduction improves the transfusion safety of platelet and plasma units, there is an associated reduction in quality. This study aimed to investigate the impact of riboflavin/ultraviolet light-treated plasma or platelets in transfusion trauma packages composed of red blood cell, plasma, and platelet units in a ratio of 1:1:1 in vitro by modeling transfusion scenarios for trauma patients and assessing function by rotational thromboelastometry. Pathogen-reduced or untreated plasma and buffy coat platelet concentrate units produced in plasma were used in different combinations with red blood cells in trauma transfusion packages. After reconstitution of these packages with hemodiluted blood, the hemostatic functionality was analyzed by rotational thromboelastometry. Hemostatic profiles of pathogen-inactivated buffy coat platelet concentrate and plasma indicated decreased activity compared with their respective controls. Reconstitution of hemodiluted blood (hematocrit = 20%) with packages that contained treated or nontreated components resulted in increased alpha and maximum clot firmness and enhanced clot-formation time. Simulating transfusion scenarios based on 30% blood replacement with a transfusion trauma package resulted in a nonsignificant difference in rotational thromboelastometry parameters between packages containing treated and nontreated blood components (p ≥ 0.05). Effects of pathogen inactivation treatment were evident when the trauma package percentage was 50% or greater and contained both pathogen inactivation-treated plasma and buffy coat platelet concentrate. Rotational thromboelastometry investigations suggest that there is relatively little impact of pathogen inactivation treatment on whole blood clot formation unless large amounts of treated components are used. © 2017 AABB.

Increased cell-free DNA concentrations in patients with obstructive sleep apnea.

PubMed

Shin, Chol; Kim, Jin K; Kim, Je H; Jung, Ki H; Cho, Kyung J; Lee, Chang K; Lee, Seung G

2008-12-01

Blood concentrations of cell-free DNA, which is considered to be released during apoptosis, are elevated under some pathological conditions such as cardiovascular disease and cancer. The association between obstructive sleep apnea (OSA) and cell-free DNA concentrations has not been reported so far. The purpose of the present study was to examine the association between OSA and plasma DNA concentrations. A case-control study was conducted using a total of 164 men aged 39-67 years, who were free of coronary heart disease and cancer. Laboratory-based overnight polysomnography was performed for all participants. On the basis of polysomnography, patients with an apnea-hypopnea index (AHI) = 5-30 events/h were defined as having mild-moderate OSA (n = 33) and those with >30 events/h were defined as having severe OSA (n = 49). All 82 controls had AHI < 5 events/h. Plasma DNA concentrations from all participants were analyzed for the beta-globin gene using fluorescence-based real-time polymerase chain reaction. Patients with severe OSA had significantly higher plasma DNA concentrations than persons with mild-moderate OSA and those without OSA (P < 0.05). AHI was significantly associated with body mass index (P < 0.001), hypertension (P < 0.001), and plasma DNA concentration (P < 0.05). After taking into account hypertension and other potential risk factors, persons with high plasma DNA concentrations (>8 microg/L) had approximately fourfold higher odds of OSA than those with low DNA levels. Further data are warranted to confirm the association for men and to evaluate the association for women.

An integrated bioanalytical method development and validation approach: case studies.

PubMed

Xue, Y-J; Melo, Brian; Vallejo, Martha; Zhao, Yuwen; Tang, Lina; Chen, Yuan-Shek; Keller, Karin M

2012-10-01

We proposed an integrated bioanalytical method development and validation approach: (1) method screening based on analyte's physicochemical properties and metabolism information to determine the most appropriate extraction/analysis conditions; (2) preliminary stability evaluation using both quality control and incurred samples to establish sample collection, storage and processing conditions; (3) mock validation to examine method accuracy and precision and incurred sample reproducibility; and (4) method validation to confirm the results obtained during method development. This integrated approach was applied to the determination of compound I in rat plasma and compound II in rat and dog plasma. The effectiveness of the approach was demonstrated by the superior quality of three method validations: (1) a zero run failure rate; (2) >93% of quality control results within 10% of nominal values; and (3) 99% incurred sample within 9.2% of the original values. In addition, rat and dog plasma methods for compound II were successfully applied to analyze more than 900 plasma samples obtained from Investigational New Drug (IND) toxicology studies in rats and dogs with near perfect results: (1) a zero run failure rate; (2) excellent accuracy and precision for standards and quality controls; and (3) 98% incurred samples within 15% of the original values. Copyright © 2011 John Wiley & Sons, Ltd.

Laser-driven electron beam and radiation sources for basic, medical and industrial sciences

PubMed Central

NAKAJIMA, Kazuhisa

2015-01-01

To date active research on laser-driven plasma-based accelerators have achieved great progress on production of high-energy, high-quality electron and photon beams in a compact scale. Such laser plasma accelerators have been envisaged bringing a wide range of applications in basic, medical and industrial sciences. Here inheriting the groundbreaker’s review article on “Laser Acceleration and its future” [Toshiki Tajima, (2010)],1) we would like to review recent progress of producing such electron beams due to relativistic laser-plasma interactions followed by laser wakefield acceleration and lead to the scaling formulas that are useful to design laser plasma accelerators with controllability of beam energy and charge. Lastly specific examples of such laser-driven electron/photon beam sources are illustrated. PMID:26062737

Dust remobilization in fusion plasmas under steady state conditions

NASA Astrophysics Data System (ADS)

Tolias, P.; Ratynskaia, S.; De Angeli, M.; De Temmerman, G.; Ripamonti, D.; Riva, G.; Bykov, I.; Shalpegin, A.; Vignitchouk, L.; Brochard, F.; Bystrov, K.; Bardin, S.; Litnovsky, A.

2016-02-01

The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization in fusion devices under steady state conditions are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic remobilization conditions—direct lift-up, sliding, rolling—are formulated. A novel experimental technique is proposed, based on controlled adhesion of dust grains on tungsten samples combined with detailed mapping of the dust deposition profile prior and post plasma exposure. Proof-of-principle experiments in the TEXTOR tokamak and the EXTRAP-T2R reversed-field pinch are presented. The versatile environment of the linear device Pilot-PSI allowed for experiments with different magnetic field topologies and varying plasma conditions that were complemented with camera observations.

Numerical simulation of inducing characteristics of high energy electron beam plasma for aerodynamics applications

NASA Astrophysics Data System (ADS)

Deng, Yongfeng; Jiang, Jian; Han, Xianwei; Tan, Chang; Wei, Jianguo

2017-04-01

The problem of flow active control by low temperature plasma is considered to be one of the most flourishing fields of aerodynamics due to its practical advantages. Compared with other means, the electron beam plasma is a potential flow control method for large scale flow. In this paper, a computational fluid dynamics model coupled with a multi-fluid plasma model is established to investigate the aerodynamic characteristics induced by electron beam plasma. The results demonstrate that the electron beam strongly influences the flow properties, not only in the boundary layers, but also in the main flow. A weak shockwave is induced at the electron beam injection position and develops to the other side of the wind tunnel behind the beam. It brings additional energy into air, and the inducing characteristics are closely related to the beam power and increase nonlinearly with it. The injection angles also influence the flow properties to some extent. Based on this research, we demonstrate that the high energy electron beam air plasma has three attractive advantages in aerodynamic applications, i.e. the high energy density, wide action range and excellent action effect. Due to the rapid development of near space hypersonic vehicles and atmospheric fighters, by optimizing the parameters, the electron beam can be used as an alternative means in aerodynamic steering in these applications.

Non-thermal plasma activates human keratinocytes by stimulation of antioxidant and phase II pathways.

PubMed

Schmidt, Anke; Dietrich, Stephan; Steuer, Anna; Weltmann, Klaus-Dieter; von Woedtke, Thomas; Masur, Kai; Wende, Kristian

2015-03-13

Non-thermal atmospheric pressure plasma provides a novel therapeutic opportunity to control redox-based processes, e.g. wound healing, cancer, and inflammatory diseases. By spatial and time-resolved delivery of reactive oxygen and nitrogen species, it allows stimulation or inhibition of cellular processes in biological systems. Our data show that both gene and protein expression is highly affected by non-thermal plasma. Nuclear factor erythroid-related factor 2 (NRF2) and phase II enzyme pathway components were found to act as key controllers orchestrating the cellular response in keratinocytes. Additionally, glutathione metabolism, which is a marker for NRF2-related signaling events, was affected. Among the most robustly increased genes and proteins, heme oxygenase 1, NADPH-quinone oxidoreductase 1, and growth factors were found. The roles of NRF2 targets, investigated by siRNA silencing, revealed that NRF2 acts as an important switch for sensing oxidative stress events. Moreover, the influence of non-thermal plasma on the NRF2 pathway prepares cells against exogenic noxae and increases their resilience against oxidative species. Via paracrine mechanisms, distant cells benefit from cell-cell communication. The finding that non-thermal plasma triggers hormesis-like processes in keratinocytes facilitates the understanding of plasma-tissue interaction and its clinical application. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Cold atmospheric plasma sterilization: from bacteria to biomolecules

NASA Astrophysics Data System (ADS)

Kong, Michael

2009-10-01

Although ionized gases have been known to have biological effects for more than 100 years, their impact on the practice in healthcare service became very significant only recently. Today, plasma-based surgical tools are used for tissue reduction and blood coagulation as surgical procedures. Most significant however is the speed at which low-temperature gas plasmas are finding new applications in medicine and biology, including plasma sterilization, wound healing, and cancer therapies just to name a few. In the terminology of biotechnology, the ``pipeline'' is long and exciting. This presentation reviews the current status of the field with a particular emphasis on plasma inactivation of microorganisms and biomolecules, for which comprehensive scientific evidence has been obtained. Some of the early speculations of biocidal plasma species are now being confirmed through a combination of optical emission spectroscopy, laser-induced fluorescence, mass spectrometry, fluid simulation and biological sensing with mutated bacteria. Similarly, fundamental studies are being performed to examine cell components targeted by gas plasmas, from membrane, through lipid and membrane proteins, to DNA. Scientific challenge is significant, as the usual complexity of plasma dynamics and plasma chemistry is compounded by the added complication that cells are live and constantly evolving. Nevertheless, the current understanding of plasma inactivation currently provides strong momentum for plasma decontamination technologies to be realized in healthcare. We will discuss the issue of protein and tissue contaminations of surgical instruments and how cold atmospheric plasmas may be used to degrade and reduce their surface load. In the context of plasma interaction with biomolecules, we will consider recent data of plasma degradation of adhesion proteins of melanoma cells. These adhesion proteins are important for cancer cell migration and spread. If low-temperature plasmas could be used to degrade them, it could form a control strategy for cancer spread. This adds to the option of plasma-triggered programmed cell death (apoptosis). Whilst opportunities thus highlighted are significant and exciting, the underpinning science poses many open questions. The presentation will then discuss main requirements for plasma sources appropriate for their biomedical applications, in terms of the scope of up-scaling, the ability to treat uneven surfaces of varying materials, the range of plasma chemistry, and the control of plasma instabilities. Finally a perspective will be offered, in terms of both opportunities and challenges.

Enhanced understanding of the MHD dynamics and ELM control experiments in KSTAR

NASA Astrophysics Data System (ADS)

Park, Hyeon K.

2013-10-01

In KSTAR, H-mode discharges have been achieved reliably at toroidal fields from 1.4 to 3.5 T with a heating power of ~ 5 MW. Using real-time plasma shape control the flattop time in H-mode has been extended to over ~ 16 s at 600 kA in the 2012 campaign and the extended plasma operation boundary has surpassed the n = 1 no-wall limit with βN /li up to 4.1. In order to achieve a high beta steady state operation in KSTAR, establishment of predictive MHD simulation and first-principle-based control of the harmful MHD are the first steps. Visualization of MHD dynamics via a 2-D Electron Cyclotron Emission Imaging (ECEI) has significantly enhanced the level of understanding of the MHD dynamics. Following the first 2-D ELM measurements in H-mode plasmas in KSTAR the measured 2-D ELM images were compared with synthetic images from the BOUT + + code. The physics of ELMs is characterized based on a wide range of measured mode numbers (n, m) local magnetic shear and pressure gradients. The observed ELM dynamics during control experiments have been enlightening and consistent with the stability models. Near the q ~ 2 surface, the island width and Δ' of the m = 2 tearing mode have been verified through the modified Rutherford model based on the 2-D images. With the aid of a second (toroidally separated) ECEI system installed in the 2012 KSTAR campaign, a 3-D reconstruction of the MHD instabilities has allowed further validation of the computed magnetic field pitch angles, rotation speeds, and toroidal asymmetries of the MHDs Work supported by NRF of Korea under contract No. 20120005920 and the U.S. DoE under contract No. DE-FG-02-99ER54531.

Development, validation and application of a micro-liquid chromatography-tandem mass spectrometry based method for simultaneous quantification of selected protein biomarkers of endothelial dysfunction in murine plasma.

PubMed

Suraj, Joanna; Kurpińska, Anna; Olkowicz, Mariola; Niedzielska-Andres, Ewa; Smolik, Magdalena; Zakrzewska, Agnieszka; Jasztal, Agnieszka; Sitek, Barbara; Chlopicki, Stefan; Walczak, Maria

2018-02-05

The objective of this study was to develop and validate the method based on micro-liquid chromatography-tandem mass spectrometry (microLC/MS-MRM) for simultaneous determination of adiponectin (ADN), von Willebrand factor (vWF), soluble form of vascular cell adhesion molecule 1 (sVCAM-1), soluble form of intercellular adhesion molecule 1 (sICAM-1) and syndecan-1 (SDC-1) in mouse plasma. The calibration range was established from 2.5pmol/mL to 5000pmol/mL for ADN; 5pmol/mL to 5000pmol/mL for vWF; 0.375pmol/mL to 250pmol/mL for sVCAM-1 and sICAM-1; and 0.25pmol/mL to 250pmol/mL for SDC-1. The method was applied to measure the plasma concentration of selected proteins in mice fed high-fat diet (HFD), and revealed the pro-thrombotic status by increased concentration of vWF (1.31±0.17 nmol/mL (Control) vs 1.98±0.09 nmol/mL (HFD), p <0.05) and the dysregulation of adipose tissue metabolism by decreased concentration of ADN (0.62±0.08 nmol/mL (Control) vs 0.37±0.06 nmol/mL (HFD), p <0.05). In conclusion, the microLC/MS-MRM-based method allows for reliable measurements of selected protein biomarkers of endothelial dysfunction in mouse plasma. Copyright © 2017 Elsevier B.V. All rights reserved.

Improving Erosion Resistance of Plasma-Sprayed Ceramic Coatings by Elevating the Deposition Temperature Based on the Critical Bonding Temperature

NASA Astrophysics Data System (ADS)

Yao, Shu-Wei; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

2018-01-01

Interlamellar bonding within plasma-sprayed coatings is one of the most important factors dominating the properties and performance of coatings. The interface bonding between lamellae significantly influences the erosion behavior of plasma-sprayed ceramic coatings. In this study, TiO2 and Al2O3 coatings with different microstructures were deposited at different deposition temperatures based on the critical bonding temperature concept. The erosion behavior of ceramic coatings was investigated. It was revealed that the coatings prepared at room temperature exhibit a typical lamellar structure with numerous unbonded interfaces, whereas the coatings deposited at the temperature above the critical bonding temperature present a dense structure with well-bonded interfaces. The erosion rate decreases sharply with the improvement of interlamellar bonding when the deposition temperature increases to the critical bonding temperature. In addition, the erosion mechanisms of ceramic coatings were examined. The unbonded interfaces in the conventional coatings act as pre-cracks accelerating the erosion of coatings. Thus, controlling interlamellar bonding formation based on the critical bonding temperature is an effective approach to improve the erosion resistance of plasma-sprayed ceramic coatings.

Newly developed double neural network concept for reliable fast plasma position control

NASA Astrophysics Data System (ADS)

Jeon, Young-Mu; Na, Yong-Su; Kim, Myung-Rak; Hwang, Y. S.

2001-01-01

Neural network is considered as a parameter estimation tool in plasma controls for next generation tokamak such as ITER. The neural network has been reported to be so accurate and fast for plasma equilibrium identification that it may be applied to the control of complex tokamak plasmas. For this application, the reliability of the conventional neural network needs to be improved. In this study, a new idea of double neural network is developed to achieve this. The new idea has been applied to simple plasma position identification of KSTAR tokamak for feasibility test. Characteristics of the concept show higher reliability and fault tolerance even in severe faulty conditions, which may make neural network applicable to plasma control reliably and widely in future tokamaks.

Gastrointestinal tolerance and plasma status of carotenoids, EPA and DHA with a fiber-enriched tube feed in hospitalized patients initiated on tube nutrition: Randomized controlled trial.

PubMed

Jakobsen, L H; Wirth, R; Smoliner, C; Klebach, M; Hofman, Z; Kondrup, J

2017-04-01

During the first days of tube feeding (TF) gastrointestinal (GI) complications are common and administration of sufficient nutrition is a challenge. Not all standard nutritionally complete formulas contain dietary fiber, fish oil or carotenoids, key dietary nutrients for health and wellbeing. The aim of this study was to investigate the effects of a fiber, fish oil and carotenoid enriched TF formula on diarrhea, constipation and nutrient bioavailability. A multi-center randomized, double-blind, controlled, parallel trial compared the effects of a dietary fiber, fish oil and carotenoid-enriched TF formula (test) with an isocaloric non-enriched formula (control) in 51 patients requiring initiation of TF. Incidence of diarrhea and constipation (based on stool frequency and consistency) was recorded daily. Plasma status of EPA, DHA and carotenoids was measured after 7 days. The incidence of diarrhea was lower in patients receiving the test formula compared with the control group (19% vs. 48%, p = 0.034). EPA and DHA status (% of total plasma phospholipids) was higher after 7 days in test compared with control group (EPA: p = 0.002, DHA: p = 0.082). Plasma carotenoid levels were higher after 7 days in the test group compared with control group (lutein: p = 0.024, α-carotene: p = 0.005, lycopene: p = 0.020, β-carotene: p = 0.054). This study suggests that the nutrient-enriched TF formula tested might have a positive effect on GI tolerance with less diarrhea incidence and significantly improved EPA, DHA and carotenoid plasma levels during the initiation of TF in hospitalized patients who are at risk of diarrhea and low nutrient status. This trial was registered at trialregister.nl; registration number 2924. Copyright © 2016. Published by Elsevier Ltd.

Quantitative analysis of aberrant protein glycosylation in liver cancer plasma by AAL-enrichment and MRM mass spectrometry.

PubMed

Ahn, Yeong Hee; Shin, Park Min; Kim, Yong-Sam; Oh, Na Ree; Ji, Eun Sun; Kim, Kwang Hoe; Lee, Yeon Jung; Kim, Sung Ho; Yoo, Jong Shin

2013-11-07

A lectin-coupled mass spectrometry (MS) approach was employed to quantitatively monitor aberrant protein glycosylation in liver cancer plasma. To do this, we compared the difference in the total protein abundance of a target glycoprotein between hepatocellular carcinoma (HCC) plasmas and hepatitis B virus (HBV) plasmas, as well as the difference in lectin-specific protein glycoform abundance of the target glycoprotein. Capturing the lectin-specific protein glycoforms from a plasma sample was accomplished by using a fucose-specific aleuria aurantia lectin (AAL) immobilized onto magnetic beads via a biotin-streptavidin conjugate. Following tryptic digestion of both the total plasma and its AAL-captured fraction of each HCC and HBV sample, targeted proteomic mass spectrometry was conducted quantitatively by a multiple reaction monitoring (MRM) technique. From the MRM-based analysis of the total plasmas and AAL-captured fractions, differences between HCC and HBV plasma groups in fucosylated glycoform levels of target glycoproteins were confirmed to arise from both the change in the total protein abundance of the target proteins and the change incurred by aberrant fucosylation on target glycoproteins in HCC plasma, even when no significant change occurs in the total protein abundance level. Combining the MRM-based analysis method with the lectin-capturing technique proved to be a successful means of quantitatively investigating aberrant protein glycosylation in cancer plasma samples. Additionally, it was elucidated that the differences between HCC and control groups in fucosylated biomarker candidates A1AT and FETUA mainly originated from an increase in fucosylation levels on these target glycoproteins, rather than an increase in the total protein abundance of the target glycoproteins.

Creatinine plasma at uncontrolled type 2 diabetes mellitus and controlled type 2 diabetes mellitus patients at primary health care in Binjai city, Indonesia

NASA Astrophysics Data System (ADS)

Rusdiana; Savira, M.; Syahputra, M.; Santoso, A.

2018-03-01

The aim of the study knowing the comparison creatinine plasma levels at uncontrolled type 2 diabetes mellitus and controlled type 2 diabetes mellitus patients at Primary Health Care in Binjai city of North Sumatera in Indonesia. This cross-sectional study was conductedon 40 type 2 Diabetes Mellitus patients who attended Primary Health Care in Binjai. Patients with age > 40 years old, (both sexes) were included in the study. We recorded different demographic parameter as age, Body Mass Index, Blood Pressure, and personal history status. And we examined the biochemicalparameters including Hba1c, Fasting Blood Sugar Levels (FBL) and creatinine serum. We separated into two groups base on HbA1c test, controlled type 2 diabetes mellitus and uncontrolled type 2 diabetes mellitus. We measured FBL by using the portable measuring instrument, and Thamrin clinical laboratory measured Hba1c, andwe measured creatinine plasmaby spectrophotometry in Biochemistry laboratory. With statistical analysis using T-test found that there was asignificant differencein creatinine plasma levels between uncontrolled type 2 diabetes mellitus with controlled type 2 diabetes mellitus (p<0.005).

Simulations of Control Schemes for Inductively Coupled Plasma Sources

NASA Astrophysics Data System (ADS)

Ventzek, P. L. G.; Oda, A.; Shon, J. W.; Vitello, P.

1997-10-01

Process control issues are becoming increasingly important in plasma etching. Numerical experiments are an excellent test-bench for evaluating a proposed control system. Models are generally reliable enough to provide information about controller robustness, fitness of diagnostics. We will present results from a two dimensional plasma transport code with a multi-species plasma chemstry obtained from a global model. [1-2] We will show a correlation of external etch parameters (e.g. input power) with internal plasma parameters (e.g. species fluxes) which in turn are correlated with etch results (etch rate, uniformity, and selectivity) either by comparison to experiment or by using a phenomenological etch model. After process characterization, a control scheme can be evaluated since the relationship between the variable to be controlled (e.g. uniformity) is related to the measurable variable (e.g. a density) and external parameter (e.g. coil current). We will present an evaluation using the HBr-Cl2 system as an example. [1] E. Meeks and J. W. Shon, IEEE Trans. on Plasma Sci., 23, 539, 1995. [2] P. Vitello, et al., IEEE Trans. on Plasma Sci., 24, 123, 1996.

Mass spectrometric identification of diagnostic markers for chronic prostatitis in seminal plasma by analysis of seminal plasma protein clinical samples.

PubMed

Rokka, A; Mehik, A; Tonttila, P; Vaarala, M

2017-08-15

There are few specific diagnostic markers for chronic prostatitis. Therefore, we used mass spectrometry to evaluate differences in seminal plasma protein expression among patients with prostatitis and young and middle-aged healthy controls. We analysed pooled seminal plasma protein samples from four prostatitis patients (two pools), three young controls (one pool), and three middle-aged controls (one pool). The samples were analysed by liquid chromatography-tandem mass spectrometry. Of the 349 proteins identified, 16 were differentially expressed between the two control pools. Five proteins were up- or down-regulated in both of the prostatitis pools compared to middle-aged controls but not between young and middle-aged pools. Progestagen-associated endometrial protein (PAEP) was over-expressed in prostatitis samples compared to young and middle-aged controls. Our findings and those of previous studies indicate that PAEP is a potential seminal plasma marker for chronic prostatitis. In conclusion, we found age-related changes in seminal plasma protein expression. PAEP expression in seminal plasma should be investigated further to evaluate its potential as a diagnostic marker for chronic prostatitis.

Characterization of a plasma photonic crystal using a multi-fluid plasma model

NASA Astrophysics Data System (ADS)

Thomas, W. R.; Shumlak, U.; Wang, B.; Righetti, F.; Cappelli, M. A.; Miller, S. T.

2017-10-01

Plasma photonic crystals have the potential to significantly expand the capabilities of current microwave filtering and switching technologies by providing high speed (μs) control of energy band-gap/pass characteristics in the GHz through low THz range. While photonic crystals consisting of dielectric, semiconductor, and metallic matrices have seen thousands of articles published over the last several decades, plasma-based photonic crystals remain a relatively unexplored field. Numerical modeling efforts so far have largely used the standard methods of analysis for photonic crystals (the Plane Wave Expansion Method, Finite Difference Time Domain, and ANSYS finite element electromagnetic code HFSS), none of which capture nonlinear plasma-radiation interactions. In this study, a 5N-moment multi-fluid plasma model is implemented using University of Washington's WARPXM finite element multi-physics code. A two-dimensional plasma-vacuum photonic crystal is simulated and its behavior is characterized through the generation of dispersion diagrams and transmission spectra. These results are compared with theory, experimental data, and ANSYS HFSS simulation results. This research is supported by a Grant from United States Air Force Office of Scientific Research.

Effect of large magnetic islands on screening of external magnetic perturbation fields at slow plasma flow

NASA Astrophysics Data System (ADS)

Li, L.; Liu, Y. Q.; Huang, X.; Luan, Q.; Zhong, F. C.

2017-02-01

A toroidal resistive magneto-hydrodynamic plasma response model, involving large magnetic islands, is proposed and numerically investigated, based on local flattening of the equilibrium pressure profile near a rational surface. It is assumed that such islands can be generated near the edge of the tokamak plasma, due to the penetration of the resonant magnetic perturbations, used for the purpose of controlling the edge localized mode. Within this model, it is found that the local flattening of the equilibrium pressure helps to mitigate the toroidal curvature induced screening effect [Glasser et al., Phys. Fluids 7, 875 (1975)]—the so called Glasser-Greene-Johnson screening, when the local toroidal flow near the mode rational surface is very slow (for example, as a result of mode locking associated with the field penetration). The saturation level of the plasma response amplitude is computed, as the plasma rotation frequency approaches zero. The local modification of the plasma resistivity inside the magnetic island is found to also affect the saturation level of the plasma response at vanishing flow.

Non-thermal plasma instabilities induced by deformation of the electron energy distribution function

NASA Astrophysics Data System (ADS)

Dyatko, N. A.; Kochetov, I. V.; Napartovich, A. P.

2014-08-01

Non-thermal plasma is a key component in gas lasers, microelectronics, medical applications, waste gas cleaners, ozone generators, plasma igniters, flame holders, flow control in high-speed aerodynamics and others. A specific feature of non-thermal plasma is its high sensitivity to variations in governing parameters (gas composition, pressure, pulse duration, E/N parameter). This sensitivity is due to complex deformations of the electron energy distribution function (EEDF) shape induced by variations in electric field strength, electron and ion number densities and gas excitation degree. Particular attention in this article is paid to mechanisms of instabilities based on non-linearity of plasma properties for specific conditions: gas composition, steady-state and decaying plasma produced by the electron beam, or by an electric current pulse. The following effects are analyzed: the negative differential electron conductivity; the absolute negative electron mobility; the stepwise changes of plasma properties induced by the EEDF bi-stability; thermo-current instability and the constriction of the glow discharge column in rare gases. Some of these effects were observed experimentally and some of them were theoretically predicted and still wait for experimental confirmation.

Experimental investigation of differential confinement effects in a rotating helicon plasma

NASA Astrophysics Data System (ADS)

Gueroult, Renaud; Evans, Eugene; Zweben, Stewart J.; Fisch, Nathaniel J.; Levinton, Fred

2014-10-01

Although plasmas have long been considered for isotope separation, challenges presented by nuclear waste remediation and nuclear spent fuel reprocessing have recently sparked a renewed interest for high-throughput plasma based mass separation techniques. Different filter concepts relying on rotating plasmas have been proposed to address these needs. However, one of the challenges common to these concepts is the need to control the plasma rotation profile, which is generally assumed to be provided by means of dedicated electrodes. An experimental effort aiming to evaluate the practicality of these plasma filter concepts has recently been started at PPPL. For this purpose, a linear helicon plasma source is used in combination with concentric ring electrodes. Preliminary biasing experiments results indicate floating potential profiles locally suitable for mass discrimination for different gas mixtures (Ar/Ne, Ar/N2, Ar/Kr). Radially resolved spectroscopic measurements and neutral gas composition analysis at two different axial positions are being planned to assess the mass separation effect. Work supported by US DOE under Contract No. DE-AC02-09CH11466.

Deposition and characterization of vanadium oxide based thin films for MOS device applications

NASA Astrophysics Data System (ADS)

Rakshit, Abhishek; Biswas, Debaleen; Chakraborty, Supratic

2018-04-01

Vanadium Oxide films are deposited on Si (100) substrate by reactive RF-sputtering of a pure Vanadium metallic target in an Argon-Oxygen plasma environment. The ratio of partial pressures of Argon to Oxygen in the sputtering-chamber is varied by controlling their respective flow rates and the resultant oxide films are obtained. MOS Capacitor based devices are then fabricated using the deposited oxide films. High frequency Capacitance-Voltage (C-V) and gate current-gate voltage (I-V) measurements reveal a significant dependence of electrical characteristics of the deposited films on their sputtering deposition parameters mainly, the relative content of Argon/Oxygen in the plasma chamber. A noteworthy change in the electrical properties is observed for the films deposited under higher relative oxygen content in the plasma atmosphere. Our results show that reactive sputtering serves as an indispensable deposition-setup for fabricating vanadium oxide based MOS devices tailor-made for Non-Volatile Memory (NVM) applications.

Effect of feed supplementation with Satureja khuzistanica essential oil on performance and physiological parameters of broilers fed on wheat- or maize-based diets.

PubMed

Masouri, L; Salari, S; Sari, M; Tabatabaei, S; Masouri, B

2017-08-01

1. The aim of this study was to evaluate various levels of Satureja khuzistanica essential oil (SKEO) on performance and physiological parameters of broilers fed on wheat- or maize-based diets. 2. Treatments consisted of two cereals (maize- or wheat-based diets) and three levels of SKEO)0, 250 and 500 mg/kg). 3. Feed intake (FI) and body weight gain (BWG) decreased in broilers fed on the wheat-based diets compared to the control diet. Dietary supplementation of 500 mg/kg SKEO increased FI and BWG. Dietary SKEO supplementation was effective in improving FI and BWG only in wheat-based diets and was effective in improving feed conversion ratio (FCR) in both diets. 4. Dietary supplementation of 500 mg/kg SKEO caused a significant decrease in plasma cholesterol and triglycerides. Also, plasma low-density lipoprotein concentration was decreased in broilers fed on 250 and 500 mg/kg of SKEO. Plasma cholesterol levels in birds fed on the wheat-based diets were lower than in those fed on maize-based diets. 5. Dietary supplementation of 500 mg/kg SKEO increased caecal population of Lactobacillus and reduced total bacterial and Escherichia coli count. Caecal population of Lactobacillus decreased in broilers fed on the wheat-based diets. 6. Digesta viscosity was increased in broilers fed on the wheat-based diets and decreased in broilers fed on 500 mg/kg SKEO compared to the control diet. Dietary SKEO supplementation was effective in reducing digesta viscosity values only in wheat-based diets. 7. Villus height of the duodenum and jejunum decreased in broilers fed on the wheat-based diets. Dietary supplementation of 500 mg/kg SKEO increased villus height and villus height-to-crypt depth ratios and decreased crypt depth of the duodenum compared to the control diet. 8. It can be concluded that dietary SKEO supplementation was effective in improving FI, BWG and FCR values in wheat-based diets.

Transition Control with Dielectric Barrier Discharge Plasmas

DTIC Science & Technology

2010-10-01

AFRL-AFOSR-UK-TR-2011-0007 Transition Control with Dielectric Barrier Discharge Plasmas Cameron Tropea Technische...Discharge Plasmas 5a. CONTRACT NUMBER FA8655-08-1-3032 5b. GRANT NUMBER Grant 08-3032 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S...is to control natural boundary-layer transition through the use of plasma actuators. Transition delay or even suppression has its merits not only in

Performance, egg quality, and blood plasma chemistry of laying hens fed hempseed and hempseed oil.

PubMed

Neijat, M; Gakhar, N; Neufeld, J; House, J D

2014-11-01

The aim of this study was to compare the performance of hens (feed intake, rate of lay, egg weight, and BW gain), egg quality and blood biochemistry (enzymes, electrolytes, proteins, and other plasma constituents) of laying hens fed diets containing hemp products. Forty-eight Lohmann LSL-Classic (white-egg layers; 19 wk of age) were individually caged and fed 1 of 6 wheat-barley-soybean-based diets for a period of 12 wk. The diets consisted of hempseed (HS; 10, 20, or 30%), hempseed oil (HO; 4.5 or 9.0%), or a control diet (corn oil-based). All diets were formulated to contain similar levels of crude fat (11%), energy (2,800 kcal/kg), and CP (17%). Data were analyzed as a completely randomized design using the repeated measure analysis of the PROC MIXED procedure of SAS. The results indicated that the inclusion of up to 30 and 9.0% HS and HO, respectively, to diets of laying hens had no significant effects on hen performance, egg quality, or plasma level of metabolites (proteins, glucose, uric acid, and cholesterol) and electrolytes (Na, K, Cl, P, and Ca). Overall plasma enzyme concentrations, particularly gamma-glutamyl transferase, were significantly (P < 0.01) lowest at the 10 and 20% levels of HS inclusion, or at the 4.5% HO level of inclusion of the hempseed products compared with the higher levels or control fed hens. Similar effects were also observed for plasma aspartate aminotransferase levels but with the HS enriched diets only (P < 0.05), particularly being lowest at the inclusion levels of 10 and 20% HS compared with the control. The results may imply a possible protective effect of HS- and HO-containing diets, particularly at 10% HS, 20% HS, and 4.5% HO levels, on liver damage/injury. In summary, both HO and HS appear to be well tolerated by laying hens as judged by markers of plasma clinical chemistry supporting the safety and efficacy of hemp products for use in laying hen rations. ©2014 Poultry Science Association Inc.

Effect of plasma-induced surface charging on catalytic processes: application to CO2 activation

NASA Astrophysics Data System (ADS)

Bal, Kristof M.; Huygh, Stijn; Bogaerts, Annemie; Neyts, Erik C.

2018-02-01

Understanding the nature and effect of the multitude of plasma-surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M = Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.

Control of linear modes in cylindrical resistive magnetohydrodynamics with a resistive wall, plasma rotation, and complex gain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brennan, D. P.; Finn, J. M.

2014-10-15

Feedback stabilization of magnetohydrodynamic (MHD) modes in a tokamak is studied in a cylindrical model with a resistive wall, plasma resistivity, viscosity, and toroidal rotation. The control is based on a linear combination of the normal and tangential components of the magnetic field just inside the resistive wall. The feedback includes complex gain, for both the normal and for the tangential components, and it is known that the imaginary part of the feedback for the former is equivalent to plasma rotation [J. M. Finn and L. Chacon, Phys. Plasmas 11, 1866 (2004)]. The work includes (1) analysis with a reducedmore » resistive MHD model for a tokamak with finite β and with stepfunction current density and pressure profiles, and (2) computations with a full compressible visco-resistive MHD model with smooth decreasing profiles of current density and pressure. The equilibria are stable for β = 0 and the marginal stability values β{sub rp,rw} < β{sub rp,iw} < β{sub ip,rw} < β{sub ip,iw} (resistive plasma, resistive wall; resistive plasma, ideal wall; ideal plasma, resistive wall; and ideal plasma, ideal wall) are computed for both models. The main results are: (a) imaginary gain with normal sensors or plasma rotation stabilizes below β{sub rp,iw} because rotation suppresses the diffusion of flux from the plasma out through the wall and, more surprisingly, (b) rotation or imaginary gain with normal sensors destabilizes above β{sub rp,iw} because it prevents the feedback flux from entering the plasma through the resistive wall to form a virtual wall. A method of using complex gain G{sub i} to optimize in the presence of rotation in this regime with β > β{sub rp,iw} is presented. The effect of imaginary gain with tangential sensors is more complicated but essentially destabilizes above and below β{sub rp,iw}.« less

Control of multidrug-resistant planktonic Acinetobacter baumannii: biocidal efficacy study by atmospheric-pressure air plasma

NASA Astrophysics Data System (ADS)

Zhe, RUAN; Yajun, GUO; Jing, GAO; Chunjun, YANG; Yan, LAN; Jie, SHEN; Zimu, XU; Cheng, CHENG; Xinghao, LIU; Shumei, ZHANG; Wenhui, DU; Paul, K. CHU

2018-04-01

In this research, an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid. The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated. According to colony forming units, nearly all the bacteria (6-log) are inactivated after 10 min of air plasma treatment. However, 7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure. Meanwhile, 86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay. The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid. The concentrations of the long-living RS, such as H2O2, {{{{NO}}}3}-, and O3, in liquid induced by plasma treatment are measured, and they increase with plasma treatment time. The changes of the intracellular ROS may be related to cell death, which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid. The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.

Development and characterization of plasma targets for controlled injection of electrons into laser-driven wakefields

NASA Astrophysics Data System (ADS)

Kleinwaechter, Tobias; Goldberg, Lars; Palmer, Charlotte; Schaper, Lucas; Schwinkendorf, Jan-Patrick; Osterhoff, Jens

2012-10-01

Laser-driven wakefield acceleration within capillary discharge waveguides has been used to generate high-quality electron bunches with GeV-scale energies. However, owing to fluctuations in laser and plasma conditions in combination with a difficult to control self-injection mechanism in the non-linear wakefield regime these bunches are often not reproducible and can feature large energy spreads. Specialized plasma targets with tailored density profiles offer the possibility to overcome these issues by controlling the injection and acceleration processes. This requires precise manipulation of the longitudinal density profile. Therefore our target concept is based on a capillary structure with multiple gas in- and outlets. Potential target designs are simulated using the fluid code OpenFOAM and those meeting the specified criteria are fabricated using femtosecond-laser machining of structures into sapphire plates. Density profiles are measured over a range of inlet pressures utilizing gas-density profilometry via Raman scattering and pressure calibration with longitudinal interferometry. In combination these allow absolute density mapping. Here we report the preliminary results.

Foundations of low-temperature plasma enhanced materials synthesis and etching

NASA Astrophysics Data System (ADS)

Oehrlein, Gottlieb S.; Hamaguchi, Satoshi

2018-02-01

Low temperature plasma (LTP)-based synthesis of advanced materials has played a transformational role in multiple industries, including the semiconductor industry, liquid crystal displays, coatings and renewable energy. Similarly, the plasma-based transfer of lithographically defined resist patterns into other materials, e.g. silicon, SiO2, Si3N4 and other electronic materials, has led to the production of nanometer scale devices that are the basis of the information technology, microsystems, and many other technologies based on patterned films or substrates. In this article we review the scientific foundations of both LTP-based materials synthesis at low substrate temperature and LTP-based isotropic and directional etching used to transfer lithographically produced resist patterns into underlying materials. We cover the fundamental principles that are the basis of successful application of the LTP techniques to technological uses and provide an understanding of technological factors that may control or limit material synthesis or surface processing with the use of LTP. We precede these sections with a general discussion of plasma surface interactions, the LTP-generated particle fluxes including electrons, ions, radicals, excited neutrals and photons that simultaneously contact and modify surfaces. The surfaces can be in the line of sight of the discharge or hidden from direct interaction for structured substrates. All parts of the article are extensively referenced, which is intended to help the reader study the topics discussed here in more detail.

Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyer, M. D.; Andre, R. G.; Gates, D. A.

This paper examines a method for real-time control of non-inductively sustained scenarios in NSTX-U by using TRANSP, a time-dependent integrated modeling code for prediction and interpretive analysis of tokamak experimental data, as a simulator. The actuators considered for control in this work are the six neutral beam sources and the plasma boundary shape. To understand the response of the plasma current, stored energy, and central safety factor to these actuators and to enable systematic design of control algorithms, simulations were run in which the actuators were modulated and a linearized dynamic response model was generated. A multi-variable model-based control schememore » that accounts for the coupling and slow dynamics of the system while mitigating the effect of actuator limitations was designed and simulated. Simulations show that modest changes in the outer gap and heating power can improve the response time of the system, reject perturbations, and track target values of the controlled values.« less

Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP

DOE PAGES

Boyer, M. D.; Andre, R. G.; Gates, D. A.; ...

2017-04-24

This paper examines a method for real-time control of non-inductively sustained scenarios in NSTX-U by using TRANSP, a time-dependent integrated modeling code for prediction and interpretive analysis of tokamak experimental data, as a simulator. The actuators considered for control in this work are the six neutral beam sources and the plasma boundary shape. To understand the response of the plasma current, stored energy, and central safety factor to these actuators and to enable systematic design of control algorithms, simulations were run in which the actuators were modulated and a linearized dynamic response model was generated. A multi-variable model-based control schememore » that accounts for the coupling and slow dynamics of the system while mitigating the effect of actuator limitations was designed and simulated. Simulations show that modest changes in the outer gap and heating power can improve the response time of the system, reject perturbations, and track target values of the controlled values.« less

Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP

NASA Astrophysics Data System (ADS)

Boyer, M. D.; Andre, R. G.; Gates, D. A.; Gerhardt, S. P.; Menard, J. E.; Poli, F. M.

2017-06-01

This paper examines a method for real-time control of non-inductively sustained scenarios in NSTX-U by using TRANSP, a time-dependent integrated modeling code for prediction and interpretive analysis of tokamak experimental data, as a simulator. The actuators considered for control in this work are the six neutral beam sources and the plasma boundary shape. To understand the response of the plasma current, stored energy, and central safety factor to these actuators and to enable systematic design of control algorithms, simulations were run in which the actuators were modulated and a linearized dynamic response model was generated. A multi-variable model-based control scheme that accounts for the coupling and slow dynamics of the system while mitigating the effect of actuator limitations was designed and simulated. Simulations show that modest changes in the outer gap and heating power can improve the response time of the system, reject perturbations, and track target values of the controlled values.

Agricultural and Food Processing Applications of Pulsed Power and Plasma Technologies

NASA Astrophysics Data System (ADS)

Takaki, Koichi

Agricultural and food processing applications of pulsed power and plasma technologies are described in this paper. Repetitively operated compact pulsed power generators with a moderate peak power are developed for the agricultural and the food processing applications. These applications are mainly based on biological effects and can be categorized as germination control of plants such as Basidiomycota and arabidopsis inactivation of bacteria in soil and liquid medium of hydroponics; extraction of juice from fruits and vegetables; decontamination of air and liquid, etc. Types of pulsed power that have biological effects are caused with gas discharges, water discharges, and electromagnetic fields. The discharges yield free radicals, UV radiation, intense electric field, and shock waves. Biologically based applications of pulsed power and plasma are performed by selecting the type that gives the target objects the adequate result from among these agents or byproducts. For instance, intense electric fields form pores on the cell membrane, which is called electroporation, or influence the nuclei. This paper mainly describes the application of the pulsed power for the germination control of Basidiomycota i.e. mushroom, inactivation of fungi in the soil and the liquid medium in hydroponics, and extraction of polyphenol from skins of grape.

Disposable cartridge biosensor platform for portable diagnostics

NASA Astrophysics Data System (ADS)

Yaras, Yusuf S.; Cakmak, Onur; Gunduz, Ali B.; Saglam, Gokhan; Olcer, Selim; Mostafazadeh, Aref; Baris, Ibrahim; Civitci, Fehmi; Yaralioglu, Goksen G.; Urey, Hakan

2017-03-01

We developed two types of cantilever-based biosensors for portable diagnostics applications. One sensor is based on MEMS cantilever chip mounted in a microfluidic channel and the other sensor is based on a movable optical fiber placed across a microfluidic channel. Both types of sensors were aimed at direct mechanical measurement of coagulation time in a disposable cartridge using plasma or whole blood samples. There are several similarities and also some important differences between the MEMS based and the optical fiber based solutions. The aim of this paper is to provide a comparison between the two solutions and the results. For both types of sensors, actuation of the cantilever or the moving fiber is achieved using an electro coil and the readout is optical. Since both the actuation and sensing are remote, no electrical connections are required for the cartridge. Therefore it is possible to build low cost disposable cartridges. The reader unit for the cartridge contains light sources, photodetectors, the electro coil, a heater, analog electronics, and a microprocessor. The reader unit has different optical interfaces for the cartridges that have MEMS cantilevers and moving fibers. MEMS based platform has better sensitivity but optomechanical alignment is a challenge and measurements with whole blood were not possible due to high scattering of light by the red blood cells. Fiber sensor based platform has relaxed optomechanical tolerances, ease of manufacturing, and it allows measurements in whole blood. Both sensors were tested using control plasma samples for activated-Partial-Thromboplastin-Time (aPTT) measurements. Control plasma test results matched with the manufacturer's datasheet. Optical fiber based system was tested for aPTT tests with human whole blood samples and the proposed platform provided repeatable test results making the system method of choice for portable diagnostics.

Carbon nanotubes on nanoporous alumina: from surface mats to conformal pore filling

PubMed Central

2014-01-01

Control over nucleation and growth of multi-walled carbon nanotubes in the nanochannels of porous alumina membranes by several combinations of posttreatments, namely exposing the membrane top surface to atmospheric plasma jet and application of standard S1813 photoresist as an additional carbon precursor, is demonstrated. The nanotubes grown after plasma treatment nucleated inside the channels and did not form fibrous mats on the surface. Thus, the nanotube growth mode can be controlled by surface treatment and application of additional precursor, and complex nanotube-based structures can be produced for various applications. A plausible mechanism of nanotube nucleation and growth in the channels is proposed, based on the estimated depth of ion flux penetration into the channels. PACS 63.22.Np Layered systems; 68. Surfaces and interfaces; Thin films and nanosystems (structure and non-electronic properties); 81.07.-b Nanoscale materials and structures: fabrication and characterization PMID:25177216

Ideal and resistive plasma resistive wall modes and control: linear and nonlinear

NASA Astrophysics Data System (ADS)

Finn, J. M.; Chacon, L.

2004-11-01

Our recent work* on control of linear and nonlinear resistive wall modes (RWM) showed that if there is an ideal plasma mode and a resistive plasma mode, and if the beta limit for the latter is lower (as is typical), then nonlinear resistive wall modes behave basically as nonlinear tearing-like modes locked to the wall. We investigate here the effect of plasma rotation sufficient to stabilize the resistive-plasma RWM but not the ideal plasma RWM. We also review results** showing the effect of normal and poloidal magnetic field sensing, and describe a simple model which is amenable to analytic solution, and which makes previously obtained simulation results transparent. *J. Finn and L. Chacon, 'Control of linear and nonlinear resistive wall modes', Phys. Plas 11, 1866 (2004). **J. Finn, 'Control of resistive wall modes in a cylindrical tokamak with radial and poloidal magnetic field sensors', to appear in Phys. Plasmas, 2004.

Overview of ion source characterization diagnostics in INTF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bandyopadhyay, M., E-mail: mainak@iter-india.org; Sudhir, Dass; Bhuyan, M.

2016-02-15

INdian Test Facility (INTF) is envisaged to characterize ITER diagnostic neutral beam system and to establish the functionality of its eight inductively coupled RF plasma driver based negative hydrogen ion source and its beamline components. The beam quality mainly depends on the ion source performance and therefore, its diagnostics plays an important role for its safe and optimized operation. A number of diagnostics are planned in INTF to characterize the ion source performance. Negative ions and its cesium contents in the source will be monitored by optical emission spectroscopy (OES) and cavity ring down spectroscopy. Plasma near the extraction regionmore » will be studied using standard electrostatic probes. The beam divergence and negative ion stripping losses are planned to be measured using Doppler shift spectroscopy. During initial phase of ion beam characterization, carbon fiber composite based infrared imaging diagnostics will be used. Safe operation of the beam will be ensured by using standard thermocouples and electrical voltage-current measurement sensors. A novel concept, based on plasma density dependent plasma impedance measurement using RF electrical impedance matching parameters to characterize the RF driver plasma, will be tested in INTF and will be validated with OES data. The paper will discuss about the overview of the complete INTF diagnostics including its present status of procurement, experimentation, interface with mechanical systems in INTF, and integration with INTF data acquisition and control systems.« less

Overview of ion source characterization diagnostics in INTF

NASA Astrophysics Data System (ADS)

Bandyopadhyay, M.; Sudhir, Dass; Bhuyan, M.; Soni, J.; Tyagi, H.; Joshi, J.; Yadav, A.; Rotti, C.; Parmar, Deepak; Patel, H.; Pillai, S.; Chakraborty, A.

2016-02-01

INdian Test Facility (INTF) is envisaged to characterize ITER diagnostic neutral beam system and to establish the functionality of its eight inductively coupled RF plasma driver based negative hydrogen ion source and its beamline components. The beam quality mainly depends on the ion source performance and therefore, its diagnostics plays an important role for its safe and optimized operation. A number of diagnostics are planned in INTF to characterize the ion source performance. Negative ions and its cesium contents in the source will be monitored by optical emission spectroscopy (OES) and cavity ring down spectroscopy. Plasma near the extraction region will be studied using standard electrostatic probes. The beam divergence and negative ion stripping losses are planned to be measured using Doppler shift spectroscopy. During initial phase of ion beam characterization, carbon fiber composite based infrared imaging diagnostics will be used. Safe operation of the beam will be ensured by using standard thermocouples and electrical voltage-current measurement sensors. A novel concept, based on plasma density dependent plasma impedance measurement using RF electrical impedance matching parameters to characterize the RF driver plasma, will be tested in INTF and will be validated with OES data. The paper will discuss about the overview of the complete INTF diagnostics including its present status of procurement, experimentation, interface with mechanical systems in INTF, and integration with INTF data acquisition and control systems.

Resolving critical dimension drift over time in plasma etching through virtual metrology based wafer-to-wafer control

NASA Astrophysics Data System (ADS)

Lee, Ho Ki; Baek, Kye Hyun; Shin, Kyoungsub

2017-06-01

As semiconductor devices are scaled down to sub-20 nm, process window of plasma etching gets extremely small so that process drift or shift becomes more significant. This study addresses one of typical process drift issues caused by consumable parts erosion over time and provides feasible solution by using virtual metrology (VM) based wafer-to-wafer control. Since erosion of a shower head has center-to-edge area dependency, critical dimensions (CDs) at the wafer center and edge area get reversed over time. That CD trend is successfully estimated on a wafer-to-wafer basis by a partial least square (PLS) model which combines variables from optical emission spectroscopy (OES), VI-probe and equipment state gauges. R 2 of the PLS model reaches 0.89 and its prediction performance is confirmed in a mass production line. As a result, the model can be exploited as a VM for wafer-to-wafer control. With the VM, advanced process control (APC) strategy is implemented to solve the CD drift. Three σ of CD across wafer is improved from the range (1.3-2.9 nm) to the range (0.79-1.7 nm). Hopefully, results introduced in this paper will contribute to accelerating implementation of VM based APC strategy in semiconductor industry.

Cerebrospinal fluid HIV escape associated with progressive neurologic dysfunction in patients on antiretroviral therapy with well controlled plasma viral load.

PubMed

Peluso, Michael J; Ferretti, Francesca; Peterson, Julia; Lee, Evelyn; Fuchs, Dietmar; Boschini, Antonio; Gisslén, Magnus; Angoff, Nancy; Price, Richard W; Cinque, Paola; Spudich, Serena

2012-09-10

To characterize HIV-infected patients with neurosymptomatic cerebrospinal fluid (CSF) 'escape', defined as detectable CSF HIV RNA in the setting of treatment-suppressed plasma levels or CSF RNA more than 1-log higher than plasma RNA. Retrospective case series. Four urban medical centers in the United States and Europe. Virologically controlled HIV-infected patients on antiretroviral therapy (ART) with progressive neurologic abnormalities who were determined to have CSF 'escape'. INTERVENTION Optimization of ART based upon drug susceptibility and presumed central nervous system exposure. Levels of CSF HIV RNA and inflammatory markers, clinical signs and symptoms, and MRI findings. Ten patients presented with new neurologic abnormalities, which included sensory, motor, and cognitive manifestations. Median CSF HIV RNA was 3900 copies/ml (range 134-9056), whereas median plasma HIV RNA was 62 copies/ml (range <50 to 380). Median CD4 T-cell count was 482 cells/μl (range 290-660). All patients had been controlled to less than 500 copies/ml for median 27.5 months (range 2-96) and five of 10 had been suppressed to less than 50 copies/ml for median 19.5 months (range 2-96). Patients had documentation of a stable ART regimen for median 21 months (range 9-60). All had CSF pleocytosis or elevated CSF protein; seven of eight had abnormalities on MRI; and six of seven harbored CSF resistance mutations. Following optimization of ART, eight of nine patients improved clinically. The development of neurologic symptoms in patients on ART with low or undetectable plasma HIV levels may be an indication of CSF 'escape'. This study adds to a growing body of literature regarding this rare condition in well controlled HIV infection.

Cerebrospinal Fluid HIV Escape Associated with Progressive Neurologic Dysfunction in Patients on Antiretroviral Therapy with Well-Controlled Plasma Viral Load

PubMed Central

Peluso, Michael J.; Ferretti, Francesca; Peterson, Julia; Lee, Evelyn; Fuchs, Dietmar; Boschini, Antonio; Gisslén, Magnus; Angoff, Nancy; Price, Richard W.; Cinque, Paola; Spudich, Serena

2013-01-01

Objective To characterize HIV-infected patients with neuro-symptomatic CSF ‘escape,’ defined as detectable CSF HIV RNA in the setting of treatment-suppressed plasma levels or CSF RNA >1 log higher than plasma RNA. Design Retrospective case series. Setting 4 urban medical centers in the United States and Europe. Subjects Virologically controlled HIV-infected patients on antiretroviral therapy (ART) with progressive neurologic abnormalities who were determined to have CSF ‘escape.’ Intervention Optimization of ART based upon drug susceptibility and presumed CNS exposure. Main outcome measures Levels of CSF HIV RNA and inflammatory markers, clinical signs and symptoms, magnetic resonance imaging findings. Results 10 patients presented with new neurological abnormalities, which included sensory, motor, and cognitive manifestations. Median CSF HIV RNA was 3900 copies/mL (range 134-9056), while median plasma HIV RNA was 62 copies/mL (range <50-380). Median CD4+ T cell count was 482 cells/mm3 (range, 290-660). All patients had been controlled <500 copies/mL for median 27.5 months (range, 2-96) and 5/10 had been suppressed <50 copies/mL for median 19.5 months (range, 2-96). Patients had documentation of a stable ART regimen for median 21 months (range 9-60). All had CSF pleocytosis or elevated CSF protein; 7/8 had abnormalities on MRI; and 6/7 harbored CSF resistance mutations. Following optimization of ART, 8/9 patients improved clinically. Conclusions The development of neurologic symptoms in patients on ART with low or undetectable plasma HIV levels may be an indication of CSF ‘escape.’ This study adds to a growing body of literature regarding this rare condition in well-controlled HIV infection. PMID:22614889

Silicon Carbide (SiC) MOSFET-based Full-Bridge for Fusion Science Applications

NASA Astrophysics Data System (ADS)

Ziemba, Timothy; Miller, Kenneth; Prager, James; Picard, Julian; Hashim, Akel

2014-10-01

Switching power amplifiers (SPAs) have a wide variety of applications within the fusion science community, including feedback and control systems for dynamic plasma stabilization in tokamaks, inductive and arc plasma sources, Radio Frequency (RF) helicity and flux injection, RF plasma heating and current drive schemes, ion beam generation, and RF pre-ionizer systems. SiC MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities. When comparing SiC and traditional silicon-based MOSFETs, SiC MOSFETs provide higher current carrying capability allowing for smaller package weights and sizes and lower operating temperature. Eagle Harbor Technologies (EHT) is designing, constructing, and testing a SiC MOSFET-based full-bridge SPA. EHT will leverage the proprietary gate drive technology previously developed with the support of a DOE SBIR, which will enable fast, efficient switching in a small form factor. The primary goal is to develop a SiC MOSFET-based SPA for fusion science applications. Work supported in part by the DOE under Contract Number DE-SC0011907.

Plasma folate levels and risk of spontaneous abortion.

PubMed

George, Lena; Mills, James L; Johansson, Anna L V; Nordmark, Anna; Olander, Bodil; Granath, Fredrik; Cnattingius, Sven

2002-10-16

Both folate deficiency and folic acid supplements have been reported to increase the risk of spontaneous abortion. The results are inconclusive, however, and measurements of folate have not been available in all studies. To study the association between plasma folate levels and the risk of spontaneous abortion. Population-based, matched, case-control study of case women with spontaneous abortion and control women from January 1996 through December 1998 in Uppsala County, Sweden. Plasma folate measurements were available for 468 cases and 921 controls at 6 to 12 gestational weeks. Risk of spontaneous abortion vs maternal plasma folate level. Compared with women with plasma folate levels between 2.20 and 3.95 ng/mL (5.0 and 8.9 nmol/L), women with low (< or =2.19 ng/mL [< or =4.9 nmol/L]) folate levels were at increased risk of spontaneous abortion (adjusted odds ratio [OR], 1.47; 95% confidence interval [CI], 1.01-2.14), whereas women with higher folate levels (3.96-6.16 ng/mL [9.0-13.9 nmol/L] and > or =6.17 ng/mL [> or =14.0 nmol/L]) showed no increased risk of spontaneous abortion (OR, 0.84; 95% CI, 0.59-1.20; and OR, 0.74; 95% CI, 0.47-1.16, respectively). Low folate levels were associated with a significantly increased risk when the fetal karyotype was abnormal (OR, 1.95; 95% CI, 1.09-3.48) but not when the fetal karyotype was normal (OR, 1.11; 95% CI, 0.55-2.24) or unknown (OR, 1.45; 95% CI, 0.90-2.33). Low plasma folate levels were associated with an increased risk of early spontaneous abortion.

Fundamentals of Aerodynamic-Flow and Combustion Control by Plasmas

DTIC Science & Technology

2010-05-14

d’un Générateur de Plasma Volumique avec Allumage sur le Banc Mercato” Report n°RT 1/11982/ONERA/ DMAE . [3] N.B. Anikin, E.N. Kukaev, S...based on the multichannel quantum defect theory (MQDT)[5], taking into account the ro-vibrational structure of the ion and of the neutral system. A...editor), "Molecular Applications of Quantum Defect Theory", IOP (1996) 6. S. Morisset et al, Phys. Rev. A 76, 042702 (2007) 7. A. Wolf et al

Helicon wave coupling in KSTAR plasmas for off-axis current drive in high electron pressure plasmas

NASA Astrophysics Data System (ADS)

Wang, S. J.; Wi, H. H.; Kim, H. J.; Kim, J.; Jeong, J. H.; Kwak, J. G.

2017-04-01

A helicon wave current drive is proposed as an efficient off-axis current drive in the high electron β plasmas that are expected in fusion reactors. A high frequency helicon wave coupling was analyzed using the surface impedance at a plasma boundary. A slow wave coupling, which may compete with the helicon wave coupling at a frequency of 500 MHz, is estimated to be lower than the fast wave coupling by an order of magnitude in the KSTAR edge plasma density and in practical Faraday shield misalignment with the magnetic pitch. A traveling wave antenna, which is a two port combline antenna, was analyzed using a simplified lumped element model. The results show that the traveling wave antenna provides load resiliency because of its insensitivity to loading resistance, provided that the loading resistance at a radiating element is limited within a practical range. The combline antenna is attractive because it does not require a matching system and exhibits a high selectivity of parallel refractive index. Based on the analysis, a seven element combline antenna was fabricated and installed at an off-mid-plane offset of 30 cm from the mid-plane in KSTAR. The low power RF characteristics measured during several plasma discharges showed no evidence of slow wave coupling. This is consistent with the expectation made through the surface impedance analysis which predicted low slow wave coupling. The wave coupling to the plasma is easily controlled by a radial outer-gap control and gas puffing. No plasma confinement degradation was observed during the radial outer-gap control of up to 3 cm in H-mode discharges. In a ELMy plasmas, only a small reflection peak was observed during a very short portion of the ELM bursting period. If the number of radiating elements is increased for high power operation, then complete load resiliency can be expected. A very large coupling can be problematic for maintaining a parallel refractive index, although this issue can be mitigated by increasing the number of elements.

Theoretical and experimental investigation into high current hollow cathode arc attachment

NASA Astrophysics Data System (ADS)

Downey, Ryan T.

This research addresses several concerns of the mechanisms controlling performance and lifetime of high-current single-channel-hollow-cathodes, the central electrode and primary life-limiting component in Magnetoplasmadynamic thrusters. Specifically covered are the trends, and the theorized governing mechanisms, seen in the discharge efficiency and power, the size of the plasma attachment to the cathode (the active zone), cathode exit plume plasma density and energy, along with plasma property distributions of the internal plasma column (the IPC) of a single-channel-hollow-cathode. Both experiment and computational modeling were employed in the analysis of the cathodes. Employing Tantalum and Tungsten cathodes (of 2, 6 and 10 mm inner diameter), experiments were conducted to measure the temperature profile of operating cathodes, the width of the active zone, the discharge voltage, power, plasma arc resistance and efficiency, with mass flow rates of 50 to 300 sccm of Argon, and discharge currents of 15 to 50 Amps. Langmuir probing was used to obtain measurements for the electron temperature, plasma density and plasma potential at the cathode exit plane (down stream tip). A computational model was developed to predict the distribution of plasma inside the cathode, based upon experimentally determined boundary conditions. It was determined that the peak cathode temperature is a function of both interior cathode density and discharge current, though the location of the peak temperature is controlled gas density but not discharge current. The active zone width was found to be an increasing function of the discharge current, but a decreasing function of the mass flow rate. The width of the active zone was found to not be controlled by the magnitude of the peak cathode wall temperature. The discharge power consumed per unit of mass throughput is seen as a decreasing function of the mass flow rate, showing the increasing efficiency of the cathode. Finally, this new understanding of the mechanisms of the plasma attachment phenomena of a single-channel-hollow-cathode were extrapolated to the multi-channel-hollow-cathode environment, to explain performance characteristics of these devices seen in previous research.

Modeling of capacitively and inductively coupled plasma for molecular decontamination

NASA Astrophysics Data System (ADS)

Mihailova, Diana; Hagelaar, Gerjan; Belenguer, Philippe; Laurent, Christopher; Lo, Juslan; Caillier, Bruno; Therese, Laurent; Guillot, Philippe

2013-09-01

This project aims to study and to develop new technology bricks for next generation of molecular decontamination systems, including plasma solution, for various applications. The contamination control in the processing stages is a major issue for the industrial performance as well as for the development of new technologies in the surface treatment area. The main task is to create uniform low temperature plasma inside a reactor containing the object to be treated. Different plasma sources are modeled with the aim of finding the most efficient one for surface decontamination: inductively coupled plasma, capacitively coupled plasma and combination of both. The model used for testing the various plasma sources is a time dependent two-dimensional multi-fluid model. The model is applied to a simplified cylindrically symmetric geometry in pure argon gas. The modeling results are validated by comparison with experimental results and observations based on optical and physical diagnostic tools. The influence of various parameters (power, pressure, flow) is studied and the corresponding results are presented, compared and discussed. This work has been performed in the frame of the collaborative program PAUD (Plasma Airborne molecular contamination Ultra Desorption) funded by the French agency OSEO and certified by French global competitive clusters Minalogic and Trimatec.

Plasma Irregularity Production in the Polar Cap F-Region Ionosphere

NASA Astrophysics Data System (ADS)

Lamarche, Leslie

Plasma in the Earth's ionosphere is highly irregular on scales ranging between a few centimeters and hundreds of kilometers. Small-scale irregularities or plasma waves can scatter radio waves resulting in a loss of signal for navigation and communication networks. The polar region is particularly susceptible to strong disturbances due to its direct connection with the Sun's magnetic field and energetic particles. In this thesis, factors that contribute to the production of decameter-scale plasma irregularities in the polar F region ionosphere are investigated. Both global and local control of irregularity production are studied, i.e. we consider global solar control through solar illumination and solar wind as well as much more local control by plasma density gradients and convection electric field. In the first experimental study, solar control of irregularity production is investigated using the Super Dual Auroral Radar Network (SuperDARN) radar at McMurdo, Antarctica. The occurrence trends for irregularities are analyzed statistically and a model is developed that describes the location of radar echoes within the radar's field-of-view. The trends are explained through variations in background plasma density with solar illumination affecting radar beam propagation. However, it is found that the irregularity occurrence during the night is higher than expected from ray tracing simulations based on a standard ionospheric density model. The high occurrence at night implies an additional source of plasma density and it is proposed that large-scale density enhancements called polar patches may be the source of this density. Additionally, occurrence maximizes around the terminator due to different competing irregularity production processes that favor a more or less sunlit ionosphere. The second study is concerned with modeling irregularity characteristics near a large-scale density gradient reversal, such as those expected near polar patches, with a particular focus on the asymmetry of the irregularity growth rate across the gradient reversal. Directional dependencies on the plasma density gradient, plasma drift, and wavevector are analyzed in the context of the recently developed general fluid theory of the gradient-drift instability. In the ionospheric F region, the strongest asymmetry is found when an elongated structure is oriented along the radar's boresight and moving perpendicular to its direction of elongation. These results have important implications for finding optimal configurations for oblique-scanning ionospheric radars such as SuperDARN to observe gradient reversals. To test the predictions of the developed model and the general theory of the gradient-drift instability, an experimental investigation is presented focusing on decameter-scale irregularities near a polar patch and the previously uninvestigated directional dependence of irregularity characteristics. Backscatter power and occurrence of irregularities are analyzed using measurements from the SuperDARN radar at Rankin Inlet, Canada, while background density gradients and convection electric fields are found from the north face of the Resolute Bay Incoherent Scatter Radar. It is shown that irregularity occurrence tends to follow the expected trends better than irregularity power, suggesting that while the gradient-drift instability may be a dominant process in generating small-scale irregularities, other mechanisms such as a shear-driven instability or nonlinear process may exert greater control over their intensity. It is concluded from this body of work that the production of small-scale plasma irregularities in the polar F-region ionosphere is controlled both by global factors such as solar illumination as well as local plasma density gradients and electric fields. In general, linear gradient-drift instability theory describes small-scale irregularity production well, particularly for low-amplitude perturbations. The production of irregularities is complex, and while ground-based radars are invaluable tools to study the ionosphere, care must be taken to interpret results correctly.

Evaluation of random plasma glucose for assessment of glycaemic control in type 2 diabetes mellitus.

PubMed

Ain, Qurratul; Latif, Atif; Jaffar, Syed Raza; Ijaz, Aamir

2017-09-01

To evaluate the accuracy of random plasma glucose in outpatients with type 2 diabetes mellitus for assessing glycaemic control. This comparative, cross-sectional study was conducted at the chemical pathology department of PNS Shifa Hospital, Karachi, from August 2015 to March 2016, and comprised data of subjects with type 2 diabetes mellitus who reported for evaluation of glycaemic control in non-fasting state. All blood samples were analysed for random plasma glucose and glycated haemoglobin. Random plasma glucose was compared as an index test with glycated haemoglobin considering it as reference standard at a value of less than 7% for good glycaemic control. SPSS 20 was used for data analysis. Of the 222 subjects, 93(42%) had good glycaemic control. Random plasma glucose showed strong positive correlation with glycated haemoglobin (p=0.000).Area under curve for random plasma glucose as determined by plotting receiver operating characteristic curve against glycated haemoglobin value of 7% was 0.89 (95% confidence interval: 0.849-0.930). Random plasma glucose at cut-off value of 150 mg/dl was most efficient for ruling out poor glycaemic control among patients with type 2 diabetes mellitus with 90.7% sensitivity and69.9% specificity and Youden's index of 0.606. Random plasma glucose may be used to reflect glycaemic control in adults with type 2 diabetes mellitus in areas where glycated haemoglobin is not feasible.

Characterization of the supersonic flowing microwave discharge using two dimensional plasma tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolic, M.; Samolov, A.; Popovic, S.

2013-03-14

A tomographic numerical method based on the two-dimensional Radon formula for a cylindrical cavity has been employed for obtaining spatial distributions of the argon excited levels. The spectroscopy measurements were taken at different positions and directions to observe populations of excited species in the plasmoid region and the corresponding excitation temperatures. Excited argon states are concentrated near the tube walls, thus, confirming the assumption that the post discharge plasma is dominantly sustained by travelling surface wave. An automated optical measurement system has been developed for reconstruction of local plasma parameters of the plasmoid structure formed in an argon supersonic flowingmore » microwave discharge. The system carries out angle and distance measurements using a rotating, flat mirror, as well as two high precision stepper motors operated by a microcontroller-based system and several sensors for precise feedback control.« less

International Space Station (ISS) Plasma Contactor Unit (PCU) Utilization Plan Assessment Update

NASA Technical Reports Server (NTRS)

Hernandez-Pellerano, Amri; Iannello, Christopher J.; Garrett, Henry B.; Ging, Andrew T.; Katz, Ira; Keith, R. Lloyd; Minow, Joseph I.; Willis, Emily M.; Schneider, Todd A.; Whittlesey, Edward J.;

Etude fondamentale des mecanismes de gravure par plasma de materiaux de pointe: Application a la fabrication de dispositifs photoniques

NASA Astrophysics Data System (ADS)

Stafford, Luc

Advances in electronics and photonics critically depend upon plasma-based materials processing either for transferring small lithographic patterns into underlying materials (plasma etching) or for the growth of high-quality films. This thesis deals with the etching mechanisms of materials using high-density plasmas. The general objective of this work is to provide an original framework for the plasma-material interaction involved in the etching of advanced materials by putting the emphasis on complex oxides such as SrTiO3, (Ba,Sr)TiO 3 and SrBi2Ta2O9 films. Based on a synthesis of the descriptions proposed by different authors to explain the etching characteristics of simple materials in noble and halogenated plasma mixtures, we propose comprehensive rate models for physical and chemical plasma etching processes. These models have been successfully validated using experimental data published in literature for Si, Pt, W, SiO2 and ZnO. As an example, we have been able to adequately describe the simultaneous dependence of the etch rate on ion and reactive neutral fluxes and on the ion energy. From an exhaustive experimental investigation of the plasma and etching properties, we have also demonstrated that the validity of the proposed models can be extended to complex oxides such as SrTiO3, (Ba,Sr)TiO 3 and SrBi2Ta2O9 films. We also reported for the first time physical aspects involved in plasma etching such as the influence of the film microstructural properties on the sputter-etch rate and the influence of the positive ion composition on the ion-assisted desorption dynamics. Finally, we have used our deep investigation of the etching mechanisms of STO films and the resulting excellent control of the etch rate to fabricate a ridge waveguide for photonic device applications. Keywords: plasma etching, sputtering, adsorption and desorption dynamics, high-density plasmas, plasma diagnostics, advanced materials, photonic applications.

Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bongers, W. A.; Beveren, V. van; Westerhof, E.

2011-06-15

An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototypemore » system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.« less

On factors influencing arc filament plasma actuator performance in control of high speed jets

NASA Astrophysics Data System (ADS)

Hahn, Casey; Kearney-Fischer, Martin; Samimy, Mo

2011-12-01

Localized arc filament plasma actuators (LAFPAs) have been developed and used at The Gas Dynamics and Turbulence Laboratory for the purpose of controlling high-speed and high Reynolds number jets. The ability of LAFPAs for use in both subsonic and supersonic jets has been explored, and experiments to date have shown that these actuators have significant potential for mixing enhancement and noise control applications. While it has been established that the actuators manipulate instabilities of the jet, the exact nature of how the actuation couples to the flow is still unclear. All of the results previously reported have been based on a nozzle extension that has an azimuthal groove of 1 mm width and 0.5 mm depth along the inner surface approximately 1 mm upstream of nozzle extension exit. The ring groove was initially added to shield the plasma arcs from the high-momentum flow. However, the effect of the ring groove on the actuation mechanism is not known. To explore this effect, a new nozzle extension is designed, which relocates the actuators to the nozzle extension face and eliminates the ring groove. Schlieren images, particle image velocimetry and acoustic results of a Mach 0.9 jet of Reynolds number ~6.1 × 105 show similar trends and magnitudes with and without a ring groove. Thus, it is concluded that the ring groove does not play a primary role in the LAFPAs' control mechanism. Furthermore, the effect of the duty cycle of the actuator input pulse on the LAFPAs' control authority is investigated. The results show that the minimum duty cycle that provides complete plasma formation has the largest control over the jet.

Effect of aspirin desensitization on T-cell cytokines and plasma lipoxins in aspirin-exacerbated respiratory disease.

PubMed

Aksu, Kurtuluş; Kurt, Emel; Alatas, Özkan; Gülbas, Zafer

2014-01-01

The pathogenesis of aspirin-exacerbated respiratory disease (AERD) is thought to be based on, mainly, overproduction of eicosanoid lipid mediators and on defective anti-inflammatory regulators. Aspirin desensitization treatment, the mainstay of controlling asthma and rhinitis in AERD patients, however, is the least understood aspect of the disease. The study was designed to determine the effect of aspirin desensitization on T-lymphocyte cytokine expression and on plasma lipoxin levels in AERD. Spirometry, skin-prick test and asthma control test were documented and intracellular cytokine expression in T lymphocytes and plasma lipoxin levels were measured in 23 AERD patients, 17 aspirin-tolerant asthmatic (ATA) patients, and 16 healthy controls. In the AERD group nasal symptom and smell scores were assessed. Of the 23 AERD patients 15 accepted to undergo aspirin desensitization protocol and 14 of them were desensitized successfully. In the desensitized AERD group, cytokine and lipoxin measurements were repeated after 1-month aspirin treatment. CD4(+) IL-10 levels were higher in AERD patients than in healthy controls and CD4(+) interferon (IFN) gamma levels were higher in AERD and ATA patients than in controls. Plasma lipoxin-A4 and 15-epi-lipoxin-A4 levels were similar among the three study groups. In the AERD group, subjects underwent aspirin desensitization followed by a 1-month aspirin treatment. Clinical parameters improved and CD4(+) IFN-gamma levels decreased significantly. No significant change in lipoxin levels was recorded. CD4(+) IFN-gamma and CD4(+) IL-10 levels in AERD patients after 1-month aspirin desensitization treatment were similar to the healthy controls. The study confirms aspirin desensitization is effective clinically in AERD patients and suggests that IFN gamma and IL-10 expression in CD4(+) T lymphocytes may be related to the mechanism of action.

Slope seeking for autonomous lift improvement by plasma surface discharge

NASA Astrophysics Data System (ADS)

Benard, Nicolas; Moreau, Eric; Griffin, John; Cattafesta, Louis N., III

2010-05-01

The present paper describes an experimental investigation of closed-loop separation control using plasma actuators. The post-stall-separated flow over a NACA 0015 airfoil is controlled using a single dielectric barrier discharge actuator located at the leading edge. Open-loop measurements are first performed to highlight the effects of the voltage amplitude on the control authority for freestream velocities of 10-30 m/s (chord Re = 1.3 × 105 to 4 × 105). The results indicate that partial or full reattachment can be achieved and motivate the choice of the slope seeking approach as the control algorithm. A single-input/single-output algorithm is used to autonomously seek the optimal voltage required to achieve the control objective (full flow reattachment associated with maximum lift). The paper briefly introduces the concept of slope seeking, and a detailed parameterization of the controller is considered. Static (fixed speed) closed-loop experiments are then discussed, which demonstrate the capability of the algorithm. In each case, the flow can be reattached in an autonomous fashion. The last part of the paper demonstrates the robustness of the gradient-based, model-free scheme for dynamic freestream conditions. This paper highlights the capability of slope seeking to autonomously achieve high lift when used to drive the voltage of a plasma actuator. It also describes the advantages and drawbacks of such a closed-loop approach.

Tungsten dust remobilization under steady-state and transient plasma conditions

DOE PAGES

Ratynskaia, S.; Tolias, P.; De Angeli, M.; ...

2016-11-22

Remobilization is one of the most prominent unresolved fusion dust-relevant issues, strongly related to the lifetime of dust in plasma-wetted regions, the survivability of dust on hot plasma-facing surfaces and the formation of dust accumulation sites. A systematic cross-machine study has been initiated to investigate the remobilization of tungsten micron-size dust from tungsten surfaces implementing a newly developed technique based on controlled pre-adhesion by gas dynamics methods. It has been utilized in a number of devices and has provided new insights on remobilization under steady-state and transient conditions. In conclusion, the experiments are interpreted with contact mechanics theory and heatmore » conduction models.« less

Dispersion properties of plasma cladded annular optical fiber

NASA Astrophysics Data System (ADS)

KianiMajd, M.; Hasanbeigi, A.; Mehdian, H.; Hajisharifi, K.

2018-05-01

One of the considerable problems in a conventional image transferring fiber optic system is the two-fold coupling of propagating hybrid modes. In this paper, using a simple and practical analytical approach based on exact modal vectorial analysis together with Maxwell's equations, we show that applying plasma as a cladding medium of an annular optical fiber can remove this defect of conventional fiber optic automatically without any external instrument as the polarization beam splitter. Moreover, the analysis indicates that the presence of plasma in the proposed optical fiber could extend the possibilities for controlling the propagation property. The proposed structure presents itself as a promising route to advanced optical processing and opens new avenues in applied optics and photonics.

MM-wave cyclotron auto-resonance maser for plasma heating

NASA Astrophysics Data System (ADS)

Ceccuzzi, S.; Dattoli, G.; Di Palma, E.; Doria, A.; Gallerano, G. P.; Giovenale, E.; Mirizzi, F.; Spassovsky, I.; Ravera, G. L.; Surrenti, V.; Tuccillo, A. A.

2014-02-01

Heating and Current Drive systems are of outstanding relevance in fusion plasmas, magnetically confined in tokamak devices, as they provide the tools to reach, sustain and control burning conditions. Heating systems based on the electron cyclotron resonance (ECRH) have been extensively exploited on past and present machines DEMO, and the future reactor will require high frequencies. Therefore, high power (≥1MW) RF sources with output frequency in the 200 - 300 GHz range would be necessary. A promising source is the so called Cyclotron Auto-Resonance Maser (CARM). Preliminary results of the conceptual design of a CARM device for plasma heating, carried out at ENEA-Frascati will be presented together with the planned R&D development.

Plasma membrane aquaporins mediates vesicle stability in broccoli

PubMed Central

Martínez-Ballesta, Maria del Carmen; García-Gomez, Pablo; Yepes-Molina, Lucía; Guarnizo, Angel L.; Teruel, José A.

2018-01-01

The use of in vitro membrane vesicles is attractive because of possible applications in therapies. Here we aimed to compare the stability and functionality of plasma membrane vesicles extracted from control and salt-treated broccoli. The impact of the amount of aquaporins was related to plasma membrane osmotic water permeability and the stability of protein secondary structure. Here, we describe for first time an increase in plant aquaporins acetylation under high salinity. Higher osmotic water permeability in NaCl vesicles has been related to higher acetylation, upregulation of aquaporins, and a more stable environment to thermal denaturation. Based on our findings, we propose that aquaporins play an important role in vesicle stability. PMID:29420651

Advanced Ignition in Supersonic Airflow by Tunable Plasma System

NASA Astrophysics Data System (ADS)

Firsov, A. A.; Dolgov, E. V.; Leonov, S. B.; Yarantsev, D. A.

2017-10-01

The plasma-based technique was studied for ignition and flameholding in a supersonic airflow in different laboratories for a long time. It was shown that flameholding of gaseous and liquid hydrocarbon fuel is feasible by means of surface DC discharge without employing mechanical flameholders in a supersonic combustion chamber. However, a high power consumption may limit application of this method in a real apparatus. This experimental and computational work explores a distributed plasma system, which allows reducing the total energy consumption and extending the life cycle of the electrode system. Due to the circuit flexibility, this approach may be potentially enriched with feedbacks for design of a close loop control system.

A Study on the Transient Behavior of Pulse Modulated Dual-Frequency Capacitive Discharges based on Circuit Analysis

NASA Astrophysics Data System (ADS)

Na, Byungkeun; Bae, Inshik; Park, Gi Jung; Chang, Hong-Young

2016-09-01

Multi-frequency capacitively coupled plasma (CCP) has been studied to independently control the ion energy and the ion flux; pulsing technique is used to reduce the electron temperature and finally the charging effects. The use of these techniques is a key to high aspect ratio contact (HARC) etching in the recent semiconductor processing. In this study, the characteristics of pulsed dual frequency (DF) CCP is investigated. Two separate powers of 3 MHz and 40 MHz are delivered to the powered electrode of an asymmetric CCP, and each frequency is modulated by an external 1 kHz pulse. Due to the complexity of the RF compensation in DF CCP, the characteristics of the plasma and the sheath are analyzed by high speed impedance measurement. The transient behavior of pulse modulated DF CCP is analyzed based on the result of continuous wave (CW) DF CCP. The optimized experimental condition for high ion energy will be presented. The difference between electronegative oxygen plasma and electropositive argon plasma is discussed as well.

PLASMA CELL LEUKEMIA

PubMed Central

de Larrea, Carlos Fernandez; Kyle, Robert A.; Durie, Brian GM; Ludwig, Heinz; Usmani, Saad; Vesole, David H.; Hajek, Roman; Miguel, Jésus San; Sezer, Orhan; Sonneveld, Pieter; Kumar, Shaji K.; Mahindra, Anuj; Comenzo, Ray; Palumbo, Antonio; Mazumber, Amitabha; Anderson, Kenneth C.; Richardson, Paul G.; Badros, Ashraf Z.; Caers, Jo; Cavo, Michele; LeLeu, Xavier; Dimopoulos, Meletios A.; Chim, CS; Schots, Rik; Noeul, Amara; Fantl, Dorotea; Mellqvist, Ulf-Henrik; Landgren, Ola; Chanan-Khan, Asher; Moreau, Philippe; Fonseca, Rafael; Merlini, Giampaolo; Lahuerta, JJ; Bladé, Joan; Orlowski, Robert Z.; Shah, Jatin J.

2014-01-01

Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic-pathologic entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10 9/L) of plasma cells in the peripheral blood. It is proposed that the thresholds for diagnosis be reexamined and consensus recommendations are made for diagnosis, as well as, response and progression criteria. Induction therapy needs to begin promptly and have high clinical activity leading to rapid disease control in an effort to minimize the risk of early death. Intensive chemotherapy regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem-cell transplantation (HDT/ASCT) if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding of the pathogenesis of PCL. PMID:23288300

Residual gas analysis for long-pulse, advanced tokamak operation.

PubMed

Klepper, C C; Hillis, D L; Bucalossi, J; Douai, D; Oddon, P; Vartanian, S; Colas, L; Manenc, L; Pégourié, B

2010-10-01

A shielded residual gas analyzer (RGA) system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This "diagnostic RGA" has been used in long-pulse (up to 6 min) discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H(2)/D(2) isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H(2) injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses (>4 min) absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H(2) could increase due to thermodesorption of overheated plasma facing components.

Plasma endotoxin activity in kangaroos with oral necrobacillosis (lumpy jaw disease) using an automated handheld testing system

PubMed Central

SOTOHIRA, Yukari; SUZUKI, Kazuyuki; SASAKI, Haruka; SANO, Tadashi; TSUCHIYA, Masakazu; SUZUKI, Yohko; SHIMAMORI, Toshio; TSUKANO, Kenji; SATO, Ayano; YOKOTA, Hiroshi; ASAKAWA, Mitsuhiko

2016-01-01

The aim of the present study was to evaluate the reliability and effectiveness of directly determining endotoxin activity in plasma samples from kangaroos with lumpy jaw disease (LJD, n=15) and healthy controls (n=12). Prior to the present study, the ability of the commercially available automated handheld portable test system (PTSTM) to detect endotoxin activity in kangaroo plasma was compared with that of the traditional LAL-kinetic turbidimetric (KT) assay. Plasma samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTSTM was not significantly different from that of the traditional LAL-based assay. The data obtained using PTSTM correlated with those using KT (r2=0.963, P<0.001). These findings indicated that the PTSTM is applicable as a simplified system to assess endotoxin activity in macropods. In the present study, we demonstrated the diagnostic value of plasma endotoxin activity in kangaroos with systemic inflammation caused by oral necrobacillosis and identified plasma endotoxin activity as a sensitive marker of systemic inflammation in kangaroos with LJD. Based on ROC curves, we proposed a diagnostic cut-off point for endotoxin activity of >0.22 EU/ml for the identification of LJD. Our results indicate that the assessment of plasma endotoxin activity is a promising diagnostic tool for determining the outcome of LJD in captive macropods. PMID:26902804

Plasma endotoxin activity in kangaroos with oral necrobacillosis (lumpy jaw disease) using an automated handheld testing system.

PubMed

Sotohira, Yukari; Suzuki, Kazuyuki; Sasaki, Haruka; Sano, Tadashi; Tsuchiya, Masakazu; Suzuki, Yohko; Shimamori, Toshio; Tsukano, Kenji; Sato, Ayano; Yokota, Hiroshi; Asakawa, Mitsuhiko

2016-07-01

The aim of the present study was to evaluate the reliability and effectiveness of directly determining endotoxin activity in plasma samples from kangaroos with lumpy jaw disease (LJD, n=15) and healthy controls (n=12). Prior to the present study, the ability of the commercially available automated handheld portable test system (PTS(TM)) to detect endotoxin activity in kangaroo plasma was compared with that of the traditional LAL-kinetic turbidimetric (KT) assay. Plasma samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS(TM) was not significantly different from that of the traditional LAL-based assay. The data obtained using PTS(TM) correlated with those using KT (r(2)=0.963, P<0.001). These findings indicated that the PTS(TM) is applicable as a simplified system to assess endotoxin activity in macropods. In the present study, we demonstrated the diagnostic value of plasma endotoxin activity in kangaroos with systemic inflammation caused by oral necrobacillosis and identified plasma endotoxin activity as a sensitive marker of systemic inflammation in kangaroos with LJD. Based on ROC curves, we proposed a diagnostic cut-off point for endotoxin activity of >0.22 EU/ml for the identification of LJD. Our results indicate that the assessment of plasma endotoxin activity is a promising diagnostic tool for determining the outcome of LJD in captive macropods.

Dissipated power and induced velocity fields data of a micro single dielectric barrier discharge plasma actuator for active flow control☆

PubMed Central

Pescini, E.; Martínez, D.S.; De Giorgi, M.G.; Francioso, L.; Ficarella, A.

2015-01-01

In recent years, single dielectric barrier discharge (SDBD) plasma actuators have gained great interest among all the active flow control devices typically employed in aerospace and turbomachinery applications [1,2]. Compared with the macro SDBDs, the micro single dielectric barrier discharge (MSDBD) actuators showed a higher efficiency in conversion of input electrical power to delivered mechanical power [3,4]. This article provides data regarding the performances of a MSDBD plasma actuator [5,6]. The power dissipation values [5] and the experimental and numerical induced velocity fields [6] are provided. The present data support and enrich the research article entitled “Optimization of micro single dielectric barrier discharge plasma actuator models based on experimental velocity and body force fields” by Pescini et al. [6]. PMID:26425667

Non-thermal plasma technology for the development of antimicrobial surfaces: a review

NASA Astrophysics Data System (ADS)

Nikiforov, Anton; Deng, Xiaolong; Xiong, Qing; Cvelbar, U.; DeGeyter, N.; Morent, R.; Leys, Christophe

2016-05-01

Antimicrobial coatings are in high demand in many fields including the biomaterials and healthcare sectors. Within recent progress in nanoscience and engineering at the nanoscale, preparation of nanocomposite films containing metal nanoparticles (such as silver nanoparticles, copper nanoparticles, zinc oxide nanoparticles) is becoming an important step in manufacturing biomaterials with high antimicrobial activity. Controlled release of antibiotic agents and eliminating free nanoparticles are of equal importance for engineering antimicrobial nanocomposite materials. Compared to traditional chemical ‘wet’ methods, plasma deposition and plasma polymerization are promising approaches for the fabrication of nanocomposite films with the advantages of gas phase dry processes, effective use of chemicals and applicability to various substrates. In this article, we present a short overview of state-of-the-art engineering of antimicrobial materials based on the use of non-thermal plasmas at low and atmospheric pressure.

Spectral broadening of characteristic γ-ray emission peaks from 12C(3He,pγ)14N reactions in fusion plasmas.

PubMed

Tardocchi, M; Nocente, M; Proverbio, I; Kiptily, V G; Blanchard, P; Conroy, S; Fontanesi, M; Grosso, G; Kneupner, K; Lerche, E; Murari, A; Cippo, E Perelli; Pietropaolo, A; Syme, B; Van Eester, D; Gorini, G

2011-11-11

The spectral broadening of characteristic γ-ray emission peaks from the reaction (12)C((3)He,pγ)(14)N was measured in D((3)He) plasmas of the JET tokamak with ion cyclotron resonance heating tuned to the fundamental harmonic of (3)He. Intensities and detailed spectral shapes of γ-ray emission peaks were successfully reproduced using a physics model combining the kinetics of the reacting ions with a detailed description of the nuclear reaction differential cross sections for populating the L1-L8 (14)N excitation levels yielding the observed γ-ray emission. The results provide a paradigm, which leverages knowledge from areas of physics outside traditional plasma physics, for the development of nuclear radiation based methods for understanding and controlling fusion burning plasmas.

Determination of plasma displacement based on eddy current diagnostics for the Keda Torus eXperiment

NASA Astrophysics Data System (ADS)

Tu, Cui; Li, Hong; Liu, Adi; Li, Zichao; Zhang, Yuan; You, Wei; Tan, Mingsheng; Luo, Bing; Adil, Yolbarsop; Hu, Jintong; Wu, Yanqi; Yan, Wentan; Xie, Jinlin; Lan, Tao; Mao, Wenzhe; Ding, Weixing; Xiao, Chijin; Zhuang, Ge; Liu, Wandong

2017-10-01

The measurement of plasma displacement is one of the most basic diagnostic tools in the study of plasma equilibrium and control in a toroidal magnetic confinement configuration. During pulse discharge, the eddy current induced in the vacuum vessel and shell will produce an additional magnetic field at the plasma boundary, which will have a significant impact on the measurement of plasma displacement using magnetic probes. In the newly built Keda Torus eXperiment (KTX) reversed field pinch device, the eddy current in the composite shell can be obtained at a high spatial resolution. This device offers a new way to determine the plasma displacement for KTX through the multipole moment expansion of the eddy current, which can be obtained by unique probe arrays installed on the inner and outer surfaces of the composite shell. In an ideal conductor shell approximation, the method of multipole moment expansion of the poloidal eddy current for measuring the plasma displacement in toroidal coordinates, is more accurate than the previous method based on symmetrical magnetic probes, which yielded results in cylindrical coordinates. Through an analytical analysis of many current filaments and numerical simulations of the current distribution in toroidal coordinates, the scaling relation between the first moment of the eddy current and the center of gravity of the plasma current is obtained. In addition, the origin of the multipole moment expansion of the eddy current in KTX is retrieved simultaneously. Preliminary data on the plasma displacement have been collected using these two methods during short pulse discharges in the KTX device, and the results of the two methods are in reasonable agreement.

First Breakthrough for Future Air-Breathing Magneto-Plasma Propulsion Systems

NASA Astrophysics Data System (ADS)

Göksel, B.; Mashek, I. Ch

2017-04-01

A new breakthrough in jet propulsion technology since the invention of the jet engine is achieved. The first critical tests for future air-breathing magneto-plasma propulsion systems have been successfully completed. In this regard, it is also the first time that a pinching dense plasma focus discharge could be ignited at one atmosphere and driven in pulse mode using very fast, nanosecond electrostatic excitations to induce self-organized plasma channels for ignition of the propulsive main discharge. Depending on the capacitor voltage (200-600 V) the energy input at one atmosphere varies from 52-320 J/pulse corresponding to impulse bits from 1.2-8.0 mNs. Such a new pulsed plasma propulsion system driven with one thousand pulses per second would already have thrust-to-area ratios (50-150 kN/m²) of modern jet engines. An array of thrusters could enable future aircrafts and airships to start from ground and reach altitudes up to 50km and beyond. The needed high power could be provided by future compact plasma fusion reactors already in development by aerospace companies. The magneto-plasma compressor itself was originally developed by Russian scientists as plasma fusion device and was later miniaturized for supersonic flow control applications. So the first breakthrough is based on a spin-off plasma fusion technology.

Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

NASA Astrophysics Data System (ADS)

Mao, Hann-Shin

Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma structure and behavior of miniature ring-cusp discharges is required. A research model was fabricated to provide a simplified experimental test bed for the analysis of the plasma discharge chamber of a miniature ion thruster. The plasma source allowed for spatially resolved measurements with a Langmuir probe along a meridian plane. Probe measurements yielded plasma density, electron temperature, and plasma potential data. The magnetic field strength was varied along with the discharge current to determine the plasma behavior under various conditions. The structure of the plasma properties were found to be independent of the discharge power under the proper scaling. It was concluded that weaker magnetic fields can improve the overall performance for ion thruster operation. To further analyze the experimental measurements, a framework was developed based on the magnetic field. A flux aligned coordinate system was developed to decouple the perpendicular and parallel plasma motion with respect to the magnetic field. This was done using the stream function and magnetic scalar potential. Magnetic formulae provided intuition on the field profiles dependence on magnet dimensions. The flux aligned coordinate system showed that the plasma was isopycnic along constant stream function values. This was used to develop an empirical relation suitable for estimating the spatial behavior and to determine the plasma volume and loss areas. The plasma geometry estimates were applied to a control volume analysis on the plasma electrons. Balancing the plasma electron generation and loss yielded nominal values used in miniature ion thrusters. This result was ultimately used to develop a design tool for miniature discharges. This tool was used to perform a parametric evaluation on the magnet field configuration of the research mode. By understanding the plasma behavior, significant improvements over the baseline configuration were obtained with relatively minor changes, thus revealing the importance of plasma structure on the performance of miniature ring-cusp discharges.

Long pulse high performance plasma scenario development for the National Spherical Torus Experiment

NASA Astrophysics Data System (ADS)

Kessel, C. E.; Bell, R. E.; Bell, M. G.; Gates, D. A.; Kaye, S. M.; LeBlanc, B. P.; Menard, J. E.; Phillips, C. K.; Synakowski, E. J.; Taylor, G.; Wilson, R.; Harvey, R. W.; Mau, T. K.; Ryan, P. M.; Sabbagh, S. A.

2006-05-01

The National Spherical Torus Experiment [Ono et al., Nucl. Fusion, 44, 452 (2004)] is targeting long pulse high performance, noninductive sustained operations at low aspect ratio, and the demonstration of nonsolenoidal startup and current rampup. The modeling of these plasmas provides a framework for experimental planning and identifies the tools to access these regimes. Simulations based on neutral beam injection (NBI)-heated plasmas are made to understand the impact of various modifications and identify the requirements for (1) high elongation and triangularity, (2) density control to optimize the current drive, (3) plasma rotation and/or feedback stabilization to operate above the no-wall β limit, and (4) electron Bernstein waves (EBW) for off-axis heating/current drive (H/CD). Integrated scenarios are constructed to provide the transport evolution and H/CD source modeling, supported by rf and stability analyses. Important factors include the energy confinement, Zeff, early heating/H mode, broadening of the NBI-driven current profile, and maintaining q(0) and qmin>1.0. Simulations show that noninductive sustained plasmas can be reached at IP=800 kA, BT=0.5 T, κ≈2.5, βN⩽5, β⩽15%, fNI=92%, and q(0)>1.0 with NBI H/CD, density control, and similar global energy confinement to experiments. The noninductive sustained high β plasmas can be reached at IP=1.0 MA, BT=0.35 T, κ≈2.5, βN⩽9, β⩽43%, fNI=100%, and q(0)>1.5 with NBI H/CD and 3.0 MW of EBW H/CD, density control, and 25% higher global energy confinement than experiments. A scenario for nonsolenoidal plasma current rampup is developed using high harmonic fast wave H/CD in the early low IP and low Te phase, followed by NBI H/CD to continue the current ramp, reaching a maximum of 480 kA after 3.4 s.

Comparison of Performance Characteristics of Aspergillus PCR in Testing a Range of Blood-Based Samples in Accordance with International Methodological Recommendations.

PubMed

Springer, Jan; White, P Lewis; Hamilton, Shanna; Michel, Denise; Barnes, Rosemary A; Einsele, Hermann; Löffler, Juergen

2016-03-01

Standardized methodologies for the molecular detection of invasive aspergillosis (IA) have been established by the European Aspergillus PCR Initiative for the testing of whole blood, serum, and plasma. While some comparison of the performance of Aspergillus PCR when testing these different sample types has been performed, no single study has evaluated all three using the recommended protocols. Standardized Aspergillus PCR was performed on 423 whole-blood pellets (WBP), 583 plasma samples, and 419 serum samples obtained from hematology patients according to the recommendations. This analysis formed a bicenter retrospective anonymous case-control study, with diagnosis according to the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (11 probable cases and 36 controls). Values for clinical performance using individual and combined samples were calculated. For all samples, PCR positivity was significantly associated with cases of IA (for plasma, P = 0.0019; for serum, P = 0.0049; and for WBP, P = 0.0089). Plasma PCR generated the highest sensitivity (91%); the sensitivities for serum and WBP PCR were 80% and 55%, respectively. The highest specificity was achieved when testing WBP (96%), which was significantly superior to the specificities achieved when testing serum (69%, P = 0.0238) and plasma (53%, P = 0.0002). No cases were PCR negative in all specimen types, and no controls were PCR positive in all specimens. This study confirms that Aspergillus PCR testing of plasma provides robust performance while utilizing commercial automated DNA extraction processes. Combining PCR testing of different blood fractions allows IA to be both confidently diagnosed and excluded. A requirement for multiple PCR-positive plasma samples provides similar diagnostic utility and is technically less demanding. Time to diagnosis may be enhanced by testing multiple contemporaneously obtained sample types. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Establishing ¹H nuclear magnetic resonance based metabonomics fingerprinting profile for spinal cord injury: a pilot study.

PubMed

Jiang, Hua; Peng, Jin; Zhou, Zhi-yuan; Duan, Yu; Chen, Wei; Cai, Bin; Yang, Hao; Zhang, Wei

2010-09-01

Spinal cord injury (SCI) is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using (1)H nuclear magnetic resonance (NMR) based metabonomics methodology and principal component analysis techniques. Nine Sprague-Dawley (SD) male rats were randomly divided into SCI, normal and sham-operation control groups. Plasma samples were collected for (1)H NMR spectroscopy 3 days after operation. The NMR data were analyzed using principal component analysis technique with Matlab software. Metabonomics analysis was able to distinguish the three groups (SCI, normal control, sham-operation). The fingerprinting atlas indicated that, compared with those without SCI, the SCI group demonstrated the following characteristics with regard to second principal component: it is made up of fatty acids, myc-inositol, arginine, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), triglyceride (TG), glucose, and 3-methyl-histamine. The data indicated that SCI results in several significant changes in plasma metabolism early on and that a metabonomics approach based on (1)H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes. The results also provided support for further development and application of metabonomics technologies for studying SCI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

The New Feedback Control System of RFX-mod Based on the MARTe Real-Time Framework

NASA Astrophysics Data System (ADS)

Manduchi, G.; Luchetta, A.; Soppelsa, A.; Taliercio, C.

2014-06-01

A real-time system has been successfully used since 2004 in the RFX-mod nuclear fusion experiment to control the position of the plasma and its Magneto Hydrodynamic (MHD) modes. However, its latency and the limited computation power of the used processors prevented the usage of more aggressive control algorithms. Therefore a new hardware and software architecture has been designed to overcome such limitations and to provide a shorter latency and a much increased computation power. The new system is based on a Linux multi-core server and uses MARTe, a framework for real-time control which is gaining interest in the fusion community.

POD analysis of flow over a backward-facing step forced by right-angle-shaped plasma actuator.

PubMed

Wang, Bin; Li, Huaxing

2016-01-01

This study aims to present flow control over the backward-facing step with specially designed right-angle-shaped plasma actuator and analyzed the influence of various scales of flow structures on the Reynolds stress through snapshot proper orthogonal decomposition (POD). 2D particle image velocimetry measurements were conducted on region (x/h = 0-2.25) and reattachment zone in the x-y plane over the backward-facing step at a Reynolds number of Re h  = 27,766 (based on step height [Formula: see text] and free stream velocity [Formula: see text]. The separated shear layer was excited by specially designed right-angle-shaped plasma actuator under the normalized excitation frequency St h  ≈ 0.345 along the 45° direction. The spatial distribution of each Reynolds stress component was reconstructed using an increasing number of POD modes. The POD analysis indicated that the flow dynamic downstream of the step was dominated by large-scale flow structures, which contributed to streamwise Reynolds stress and Reynolds shear stress. The intense Reynolds stress localized to a narrow strip within the shear layer was mainly affected by small-scale flow structures, which were responsible for the recovery of the Reynolds stress peak. With plasma excitation, a significant increase was obtained in the vertical Reynolds stress peak. Under the dimensionless frequencies St h  ≈ 0.345 and [Formula: see text] which are based on the step height and momentum thickness, the effectiveness of the flow control forced by the plasma actuator along the 45° direction was ordinary. Only the vertical Reynolds stress was significantly affected.

The effects of copper on blood and biochemical parameters of rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Dethloff, G.M.; Schlenk, D.; Khan, S.; Bailey, H.C.

1999-01-01

Metals are released into aquatic systems from many sources, often at sublethal concentrations. The effects of sublethal concentrations of metals on fish are not entirely understood. The objective of this study was to determine the hematological and biochemical effects of a range of copper concentrations (6.4, 16.0, 26.9 ??g Cu/L) on rainbow trout (Oncorhynchus mykiss) over a prolonged period of time. Trout were exposed to copper, and, at intervals of 3, 7, 14, and 21 days, selected parameters were evaluated. Hemoglobin, hematocrit, plasma glucose, and plasma cortisol levels were elevated in trout exposed to 26.9 ??g Cu/L at day 3 and then returned to levels comparable to control fish. Plasma protein and lactate levels were not significantly altered in trout from any copper treatment. Hepatic copper concentration and hepatic metallothionein mRNA expression were consistently elevated in trout exposed to 26.9 ??g Cu/L. Both of these parameters stabilized by day 3, with only hepatic copper concentration showing a further increase at day 21. Hepatic copper concentration and hepatic metallothionein mRNA expression appear to be robust indicators of copper exposure. Most blood-based parameters evaluated appear to be associated with a transitory, nonspecific stress response. The return of elevated hematological and biochemical parameters to control levels after 3 days and thestabilization of hepatic metallothionein mRNA expression and copper concentration over a similar time period suggested acclimation to dissolved copper at 26.9 ??g/L. Further analysis of the data on blood-based parameters indicated that certain parameters (hemoglobin, hematocrit, plasma glucose, plasma cortisol) may be useful in field monitoring.

Co-amplification at lower denaturation-temperature PCR combined with unlabled-probe high-resolution melting to detect KRAS codon 12 and 13 mutations in plasma-circulating DNA of pancreatic adenocarcinoma cases.

PubMed

Wu, Jiong; Zhou, Yan; Zhang, Chun-Yan; Song, Bin-Bin; Wang, Bei-Li; Pan, Bai-Shen; Lou, Wen-Hui; Guo, Wei

2014-01-01

The aim of our study was to establish COLD-PCR combined with an unlabeled-probe HRM approach for detecting KRAS codon 12 and 13 mutations in plasma-circulating DNA of pancreatic adenocarcinoma (PA) cases as a novel and effective diagnostic technique. We tested the sensitivity and specificity of this approach with dilutions of known mutated cell lines. We screened 36 plasma-circulating DNA samples, 24 from the disease control group and 25 of a healthy group, to be subsequently sequenced to confirm mutations. Simultaneously, we tested the specimens using conventional PCR followed by HRM and then used target-DNA cloning and sequencing for verification. The ROC and respective AUC were calculated for KRAS mutations and/or serum CA 19-9. It was found that the sensitivity of Sanger reached 0.5% with COLD- PCR, whereas that obtained after conventional PCR did 20%; that of COLD-PCR based on unlabeled-probe HRM, 0.1%. KRAS mutations were identified in 26 of 36 PA cases (72.2%), while none were detected in the disease control and/or healthy group. KRAS mutations were identified both in 26 PA tissues and plasma samples. The AUC of COLD-PCR based unlabeled probe HRM turned out to be 0.861, which when combined with CA 19-9 increased to 0.934. It was concluded that COLD-PCR with unlabeled-probe HRM can be a sensitive and accurate screening technique to detect KRAS codon 12 and 13 mutations in plasma-circulating DNA for diagnosing and treating PA.

Spectroscopic analysis technique for arc-welding process control

NASA Astrophysics Data System (ADS)

Mirapeix, Jesús; Cobo, Adolfo; Conde, Olga; Quintela, María Ángeles; López-Higuera, José-Miguel

2005-09-01

The spectroscopic analysis of the light emitted by thermal plasmas has found many applications, from chemical analysis to monitoring and control of industrial processes. Particularly, it has been demonstrated that the analysis of the thermal plasma generated during arc or laser welding can supply information about the process and, thus, about the quality of the weld. In some critical applications (e.g. the aerospace sector), an early, real-time detection of defects in the weld seam (oxidation, porosity, lack of penetration, ...) is highly desirable as it can reduce expensive non-destructive testing (NDT). Among others techniques, full spectroscopic analysis of the plasma emission is known to offer rich information about the process itself, but it is also very demanding in terms of real-time implementations. In this paper, we proposed a technique for the analysis of the plasma emission spectrum that is able to detect, in real-time, changes in the process parameters that could lead to the formation of defects in the weld seam. It is based on the estimation of the electronic temperature of the plasma through the analysis of the emission peaks from multiple atomic species. Unlike traditional techniques, which usually involve peak fitting to Voigt functions using the Levenberg-Marquardt recursive method, we employ the LPO (Linear Phase Operator) sub-pixel algorithm to accurately estimate the central wavelength of the peaks (allowing an automatic identification of each atomic species) and cubic-spline interpolation of the noisy data to obtain the intensity and width of the peaks. Experimental tests on TIG-welding using fiber-optic capture of light and a low-cost CCD-based spectrometer, show that some typical defects can be easily detected and identified with this technique, whose typical processing time for multiple peak analysis is less than 20msec. running in a conventional PC.

High Speed and High Functional Inverter Power Supplies for Plasma Generation and Control, and their Performance

NASA Astrophysics Data System (ADS)

Uesugi, Yoshihiko; Razzak, Mohammad A.; Kondo, Kenji; Kikuchi, Yusuke; Takamura, Shuichi; Imai, Takahiro; Toyoda, Mitsuhiro

The Rapid development of high power and high speed semiconductor switching devices has led to their various applications in related plasma fields. Especially, a high speed inverter power supply can be used as an RF power source instead of conventional linear amplifiers and a power supply to control the magnetic field in a fusion plasma device. In this paper, RF thermal plasma production and plasma heating experiments are described emphasis placed on using a static induction transistor inverter at a frequency range between 200 kHz and 2.5 MHz as an RF power supply. Efficient thermal plasma production is achieved experimentally by using a flexible and easily operated high power semiconductor inverter power supply. Insulated gate bipolar transistor (IGBT) inverter power supplies driven by a high speed digital signal processor are applied as tokamak joule coil and vertical coil power supplies to control plasma current waveform and plasma equilibrium. Output characteristics, such as the arbitrary bipolar waveform generation of a pulse width modulation (PWM) inverter using digital signal processor (DSP) can be successfully applied to tokamak power supplies for flexible plasma current operation and fast position control of a small tokamak.

Method and apparatus for upshifting light frequency by rapid plasma creation

DOEpatents

Dawson, John M.; Wilks, Scott C.; Mori, Warren B.; Joshi, Chandrasekhar J.; Sessler, Andrew M.

1990-01-01

Photons of an electromagnetic source wave are frequency-upshifted as a plasma is rapidly created around the path of this propagating source wave. The final frequency can be controlled by adjusting the gas density. A controlled time-varying frequency (chirped) pulse can be produced by using a controlled spatially varying gas density. The plasma must be created in a time which is short compared to the transit time of the light through the plasmas region. For very fast creation over one to at most a few light periods of an overdense plasma, static magnetic fields with short wavelengths are created.

Independent control of electron energy and density using a rotating magnetic field in inductively coupled plasmas

NASA Astrophysics Data System (ADS)

Kondo, Takahiro; Ohta, Masayuki; Ito, Tsuyohito; Okada, Shigefumi

2013-09-01

Effects of a rotating magnetic field (RMF) on the electron energy distribution function (EEDF) and on the electron density are investigated with the aim of controlling the radical composition of inductively coupled plasmas. By adjusting the RMF frequency and generation power, the desired electron density and electron energy shift are obtained. Consequently, the amount and fraction of high-energy electrons, which are mostly responsible for direct dissociation processes of raw molecules, will be controlled externally. This controllability, with no electrode exposed to plasma, will enable us to control radical components and their flux during plasma processing.

Numerical simulation and sensitivity analysis of a low-Reynolds-number flow around a square cylinder controlled using plasma actuators

NASA Astrophysics Data System (ADS)

Anzai, Yosuke; Fukagata, Koji; Meliga, Philippe; Boujo, Edouard; Gallaire, François

2017-04-01

Flow around a square cylinder controlled using plasma actuators (PAs) is numerically investigated by direct numerical simulation in order to clarify the most effective location of actuator installation and to elucidate the mechanism of control effect. The Reynolds number based on the cylinder diameter and the free-stream velocity is set to be 100 to study the fundamental effect of PAs on two-dimensional vortex shedding, and three different locations of PAs are considered. The mean drag and the root-mean-square of lift fluctuations are found to be reduced by 51% and 99% in the case where two opposing PAs are aligned vertically on the rear surface. In that case, a jet flow similar to a base jet is generated by the collision of the streaming flows induced by the two opposing PAs, and the vortex shedding is completely suppressed. The simulation results are ultimately revisited in the frame of linear sensitivity analysis, whose computational cost is much lower than that of performing the full simulation. A good agreement is reported for low control amplitudes, which allows further discussion of the linear optimal arrangement for any number of PAs.

Pulsed plasma thrusters for small spacecraft attitude control

NASA Technical Reports Server (NTRS)

McGuire, Melissa L.; Myers, Roger M.

1996-01-01

Pulsed Plasma Thrusters (PPTS) are a new option for attitude control of a small spacecraft and may result in reduced attitude control system (ACS) mass and cost. The primary purpose of an ACS is to orient the spacecraft to the desired accuracy in inertial space. The ACS functions for which the PPT system will be analyzed include disturbance torque compensation, and slewing maneuvers such as sun acquisition for which the small impulse bit and high specific impulse of the PPT offers unique advantages. The NASA Lewis Research Center (LERC) currently has a contracted flight PPT system development program in place with Olin Aerospace with a delivery date of October 1997. The PPT systems in this study are based upon the work being done under the NASA LERC program. Analysis of the use of PPTs for ACS showed that the replacement of the standard momentum wheels and torque rods with a PPT system to perform the attitude control maneuvers on a small low Earth orbiting spacecraft reduced the ACS mass by 50 to 75% with no increase in required power level over comparable wheel-based systems, though rapid slewing power requirements may present an issue.

Quantitation of plasma thiamine, related metabolites and plasma protein oxidative damage markers in children with autism spectrum disorder and healthy controls.

PubMed

Anwar, Attia; Marini, Marina; Abruzzo, Provvidenza Maria; Bolotta, Alessandra; Ghezzo, Alessandro; Visconti, Paola; Thornalley, Paul J; Rabbani, Naila

2016-11-01

To assess thiamine and related metabolite status by analysis of plasma and urine in autistic children and healthy controls, correlations to clinical characteristics and link to plasma protein markers of oxidative damage. 27 children with autism (21 males and 6 females) and 21 (15 males and 6 females) age-matched healthy control children were recruited. The concentration of thiamine and related phosphorylated metabolites in plasma and urine and plasma protein content of dityrosine, N-formylkynurenine and 3-nitrotyrosine was determined. Plasma thiamine and thiamine monophosphate concentrations were similar in both study groups (median [lower-upper quartile]): autistic children - 6.60 nM (4.48-8.91) and 7.00 nM (5.51-8.55), and healthy controls - 6.82 nM (4.47-7.02) and 6.82 nM (5.84-8.91), respectively. Thiamine pyrophosphate (TPP) was decreased 24% in autistic children compared to healthy controls: 6.82 nM (5.81-8.52) versus 9.00 nM (8.41-10.71), p < .01. Urinary excretion of thiamine and fractional renal clearance of thiamine did not change between the groups. No correlation was observed between clinical markers and the plasma and urine thiamine concentration. Plasma protein dityrosine content was increased 88% in ASD. Other oxidative markers were unchanged. Autistic children had normal plasma and urinary thiamine levels whereas plasma TPP concentration was decreased. The latter may be linked to abnormal tissue handling and/or absorption from gut microbiota of TPP which warrants further investigation. Increased plasma protein dityrosine may reflect increased dual oxidase activity in response to change in mucosal immunity and host-microbe homeostasis.

FREQUENCY CONTROL OF RF HEATING OF GASEOUS PLASMA

DOEpatents

Herold, E.W.

1962-09-01

This invention relates to the heating of gaseous plasma by radiofrequency ion-cyclotron resonance heating. The cyclotron resonance frequencies are varied and this invention provides means for automatically controlling the frequency of the radiofrequency to maximize the rate of heating. To this end, a servo-loop is provided to sense the direction of plasma heating with frequency and a control signal is derived to set the center frequency of the radiofrequency energy employed to heat the plasma. (AEC)

Copper in Diabetes Mellitus: a Meta-Analysis and Systematic Review of Plasma and Serum Studies.

PubMed

Qiu, Qihong; Zhang, Fuping; Zhu, Wenjun; Wu, Juan; Liang, Min

2017-05-01

Copper (Cu) is an important trace element involved in oxidative stress, which is associated with the onset and progression of diabetes mellitus (DM). However, clinical studies comparing plasma or serum Cu levels in patients with DM and in healthy individuals report conflicting findings. Therefore, in this meta-analysis, we analyzed the circulating levels of Cu associated with DM (including type 1 diabetes mellitus [T1DM] and type 2 diabetes mellitus [T2DM]). We searched the articles indexed in PubMed, OVID, and Cochrane databases, published through January 2016 and meeting our predefined criteria. Requisite data were extracted, and a random-effect model or a fixed-effect model was used to conduct the meta-analysis. Fifteen eligible studies involving a total of 1079 DM patients and 561 healthy controls were identified. Overall, the DM patients showed higher Cu levels than the healthy controls (plasma Cu mean difference [MD] = 1.69 μmol/L, p < 0.0001; serum Cu MD = 4.06 μmol/L, p = 0.005; plasma and serum Cu MD = 2.67 μmol/L, p = 0.006). Stratification based on the type of diabetes also indicated higher levels of Cu in the plasma and serum of DM patients than in healthy controls, respectively. Stratification of DM patients associated with and without complications also revealed similar results. This meta-analysis suggests that DM patients carried higher levels of Cu than healthy individuals. However, international cohort studies are needed to corroborate our findings.

Acute Lung Injury in Patients with Traumatic Injuries: Utility of a Panel of Biomarkers for Diagnosis and Pathogenesis

PubMed Central

Fremont, Richard D.; Koyama, Tatsuki; Calfee, Carolyn S.; Wu, William; Dossett, Lesly A.; Bossert, Fred R.; Mitchell, Daphne; Wickersham, Nancy; Bernard, Gordon R.; Matthay, Michael A.; May, Addison K.; Ware, Lorraine B.

2012-01-01

Background The diagnosis of acute lung injury (ALI) is based on a consensus clinical definition. Despite the simplicity of this definition, ALI remains underdiagnosed and undertreated. Severe trauma is a well-described cause of ALI that represents a relatively homogeneous subset of ALI patients. The goals of this study were to develop a panel of plasma biomarkers to facilitate diagnosis of trauma-induced ALI and to enhance our understanding of the pathogenesis of human ALI. Methods A retrospective nested case control of 192 patients admitted to the trauma intensive care unit (ICU) at a university hospital between 2002 and 2006. We compared 107 patients with ALI to 85 patients without ALI. Plasma was collected within 72 h of ICU admission. Twenty-one plasma biomarkers were measured in duplicate in each plasma sample. Results Patients with ALI had higher severity of illness scores, more days of mechanical ventilation, longer hospital stays and higher mortality versus controls. Seven biomarkers (RAGE, PCPIII, BNP, ANG2, IL10, TNF-α, and IL8) had a high diagnostic accuracy as reflected by the area under the receiver operating characteristic curve of 0.86 (95% CI 0.82 – 0.92) in differentiating ALI from controls. Conclusions A model utilizing seven plasma biomarkers had a high diagnostic accuracy in differentiating patients with trauma-induced ALI from trauma patients without ALI. In addition, use of a panel of biomarkers provides insight into the likely importance of alveolar epithelial injury in the pathogenesis of early acute lung injury. PMID:20038857

Progress in Development of the ITER Plasma Control System Simulation Platform

NASA Astrophysics Data System (ADS)

Walker, Michael; Humphreys, David; Sammuli, Brian; Ambrosino, Giuseppe; de Tommasi, Gianmaria; Mattei, Massimiliano; Raupp, Gerhard; Treutterer, Wolfgang; Winter, Axel

2017-10-01

We report on progress made and expected uses of the Plasma Control System Simulation Platform (PCSSP), the primary test environment for development of the ITER Plasma Control System (PCS). PCSSP will be used for verification and validation of the ITER PCS Final Design for First Plasma, to be completed in 2020. We discuss the objectives of PCSSP, its overall structure, selected features, application to existing devices, and expected evolution over the lifetime of the ITER PCS. We describe an archiving solution for simulation results, methods for incorporating physics models of the plasma and physical plant (tokamak, actuator, and diagnostic systems) into PCSSP, and defining characteristics of models suitable for a plasma control development environment such as PCSSP. Applications of PCSSP simulation models including resistive plasma equilibrium evolution are demonstrated. PCSSP development supported by ITER Organization under ITER/CTS/6000000037. Resistive evolution code developed under General Atomics' Internal funding. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.

On the nonlinear trapping nature of undamped, coherent structures in collisionless plasmas and its impact on stability

NASA Astrophysics Data System (ADS)

Schamel, Hans; Mandal, Debraj; Sharma, Devendra

2017-03-01

An outstanding notion for collisionless plasmas is the essential nonlinear character of their coherent structures, which in the stationary, weak amplitude limit are described by a continuum of cnoidal electron and ion hole modes governed by a multiparametric nonlinear dispersion relation. The well-known discrete structure of undamped linear plasma modes is seamlessly embedded in this nonlinear continuum as the microscopic texture of plasma begins to reveal itself in the high temperature collisionless plasma limit. This transforms the linear-threshold-based operating mechanism of plasma turbulence into a fundamental nonlinear, multifaceted one. Based on a comprehensive three-level description of increasing profundity, a proof of this novel dictum is presented, which makes use of the joint properties of such structures, their coherency and stationarity, and uses in succession a fluid, linear Vlasov and a full Vlasov description. It unifies discrete and continuum limits by resolving the inevitable resonant region and shows that coherent electrostatic equilibria are generally controlled by kinetic particle trapping and are hence fundamentally nonlinear. By forging a link between damped and growing wave solutions, these modes render plasma stability complex and difficult to evaluate due to the entangled pattern of the stability boundary in function and parameter space, respectively. A direct consequence is the existence of negative energy modes of arbitrarily small amplitudes in the subcritical region of the two-stream instability as well as the failure of linear Landau (Vlasov, van Kampen) theory, whenever resonant particles are involved, in addressing the onset of instability in a current-carrying plasma. Responsible for this subtle phase space behavior is hence the thresholdless omnipresence of the trapping nonlinearity originating from coherency. A high resolution, exact-mass-ratio, multispecies, and collisionless plasma simulation is employed to illustrate exemplarily how tiny seed fluctuations in phase-space can act as a triggering agent for a subcritical plasma excitation verifying an access to these modes in the noisy, collisionless plasma limit.

Characterization of Wet Air Plasma Jet Powered by Sinusoidal High Voltage and Nanosecond Pulses for Plasma Agricultural Application

NASA Astrophysics Data System (ADS)

Takashima, Keisuke; Shimada, Keisuke; Konishi, Hideaki; Kaneko, Toshiro

2015-09-01

Not only for the plasma sterilization but also for many of plasma life-science applications, atmospheric pressure plasma devices that allowed us to control its state and reactive species production are deserved to resolve the roles of the chemical species. Influence of the hydroxyl radical and ozone on germination of conidia of a strawberry pathogen is presented. Water addition to air plasma jet significantly improves germination suppression performance, while measured reactive oxygen species (ROS) are reduced. Although the results show a negative correlation between ROS and the germination suppression, this infers the importance of chemical composition generated by plasma. For further control of the plasma product, a plasma jet powered by sinusoidal high voltage and nanosecond pulses is developed and characterized with the voltage-charge Lissajous. Control of breakdown phase and discharge power by pulse-imposed phase is presented. This work is supported by JSPS KAKENHI Grant-in-Aid for Young Scientists (B) Grant Number 15K17480 and Exploratory Research Grant Number 23644199.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goumiri, I. R.; Rowley, C. W.; Sabbagh, S. A.

In this study, a model-based feedback system is presented enabling the simultaneous control of the stored energy through β n and the toroidal rotation profile of the plasma in National Spherical Torus eXperiment Upgrade device. Actuation is obtained using the momentum from six injected neutral beams and the neoclassical toroidal viscosity generated by applying three-dimensional magnetic fields. Based on a model of the momentum diffusion and torque balance, a feedback controller is designed and tested in closed-loop simulations using TRANSP, a time dependent transport analysis code, in predictive mode. Promising results for the ongoing experimental implementation of controllers are obtained.

[Blood gas and acid-base changes and rhythmologic tolerance of acetate and bicarbonate hemodialysis using a standard dialyser with high sodium and control of ultrafiltration].

PubMed

Westeel, P F; Coevoet, B; Bens, J L; Neuville, M; Morinière, P; Fievet, P; Dkhissi, H; Fournier, A

1983-01-01

In order to demonstrate a possible superiority of bicarbonate dialysis (HDB) over acetate dialysis (HDA) in conditions of standard dialysis (4 hours on a 1 m2 cuprophan dialyser) but with a bath rich in sodium (143 mEq/l) and control of ultrafiltration, we have compared 2 sequences of 3 runs of HDA and HDB with these conditions in 8 patients as regards their acido-basic and cardiologic parameters (continuous monitoring of ECG by Holter, regular measurement of blood pressure). Acid base balance study in AHD led to the distinction of 2 groups according to wether their plasma bicarbonate increased or decreased during the run. Rythmological tolerance was the same in BHD and AHD, wether all patients or both groups were considered. Heart rate was however slightly but significantly higher during AHD than during BHD, in the patients whose plasma bicarbonate decreased. In conclusion, the benefit of HDB is not remarkable when HDA is performed not only in standard conditions but also with a bath rich in sodium and with control of ultrafiltration.

Validation of the SHOX2/PTGER4 DNA Methylation Marker Panel for Plasma-Based Discrimination between Patients with Malignant and Nonmalignant Lung Disease.

PubMed

Weiss, Gunter; Schlegel, Anne; Kottwitz, Denise; König, Thomas; Tetzner, Reimo

2017-01-01

Low-dose computed tomography (LDCT) is used for screening for lung cancer (LC) in high-risk patients in the United States. The definition of high risk and the impact of frequent false-positive results of low-dose computed tomography remains a challenge. DNA methylation biomarkers are valuable noninvasive diagnostic tools for cancer detection. This study reports on the evaluation of methylation markers in plasma DNA for LC detection and discrimination of malignant from nonmalignant lung disease. Circulating DNA was extracted from 3.5-mL plasma samples, treated with bisulfite using a commercially available kit, purified, and assayed by real-time polymerase chain reaction for assessment of DNA methylation of short stature homeobox 2 gene (SHOX2), prostaglandin E receptor 4 gene (PTGER4), and forkhead box L2 gene (FOXL2). In three independent case-control studies these assays were evaluated and optimized. The resultant assay, a triplex polymerase chain reaction combining SHOX2, PTGER4, and the reference gene actin, beta gene (ACTB), was validated using plasma from patients with and without malignant disease. A panel of SHOX2 and PTGER4 provided promising results in three independent case-control studies examining a total of 330 plasma specimens (area under the receiver operating characteristic curve = 91%-98%). A validation study with 172 patient samples demonstrated significant discriminatory performance in distinguishing patients with LC from subjects without malignancy (area under the curve = 0.88). At a fixed specificity of 90%, sensitivity for LC was 67%; at a fixed sensitivity of 90%, specificity was 73%. Measurement of SHOX2 and PTGER4 methylation in plasma DNA allowed detection of LC and differentiation of nonmalignant diseases. Development of a diagnostic test based on this panel may provide clinical utility in combination with current imaging techniques to improve LC risk stratification. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

An Analysis of Unseasonal Equatorial Plasma Bubbles in July 2014

NASA Astrophysics Data System (ADS)

Carter, B. A.; Currie, J. L.; Pradipta, R.; Groves, K. M.; Caton, R. G.; Yokoyama, T.

2017-12-01

In the equatorial ionosphere, the Raleigh-Taylor (RT) plasma instability in the post sunset region is known to cause plasma depletions, known as equatorial plasma bubbles (EPBs). These EPBs can have adverse effects on satellite-reliant technologies by causing scintillations in the phase and amplitude of Global Navigation Satellite System (GNSS) signals. The effect of EPBs on satellite-reliant technologies highlights a need for reliable forecasting of EPBs in the low-latitude regions, which requires a solid understanding of their climatology and daily variability. The climatology of EPB occurrence is known to correlate with the angle between the magnetic field and solar terminator. This angle controls the longitudinal E-region conductivity gradient across the day-night terminator, which influences the strength of the pre-reversal enhancement in the upward plasma drift, a dominant term in the linear RT growth rate. This relationship is well established from ground-based GNSS and satellite-based studies. However, reliable forecasts have not been developed by space weather forecasting agencies due to the lack of understanding of EPB daily variability. During July, EPB occurrence is small in the South-East Asia longitude sector due to the relatively large angle between the magnetic field and solar terminator. As a result, the pre-reversal enhancement in the upward plasma drift is typically low during this period, creating less favourable conditions for EPB growth. However, despite the typically low pre-reversal enhancement strength, this analysis reveals that July 2014 is not devoid of EPB events above South-East Asia. These unseasonal EPB events during July 2014 are studied in the context of the prevalently low solar and geomagnetic activity conditions. Given the lack of solar and geomagnetic control, the influence of the lower atmosphere on EPB generation (e.g., via atmospheric gravity wave seeding) is explored. These events provide a unique opportunity to investigate the factors that affect the daily variability of EPBs, which will contribute towards the development of EPB prediction capabilities.

A key role for mitochondria in endothelial signaling by plasma cysteine/cystine redox potential

PubMed Central

Go, Young-Mi; Park, Heonyong; Koval, Michael; Orr, Michael; Reed, Matthew; Liang, Yongliang; Smith, Debra; Pohl, Jan; Jones, Dean P.

2011-01-01

The redox potential of the plasma cysteine/cystine couple (EhCySS) is oxidized in association with risk factors for cardiovascular disease (CVD), including age, smoking, type 2 diabetes, obesity, and alcohol abuse. Previous in vitro findings support a cause–effect relationship for extracellular EhCySS in cell signaling pathways associated with CVD, including those controlling monocyte adhesion to endothelial cells. In this study, we provide evidence that mitochondria are a major source of reactive oxygen species (ROS) in the signaling response to a more oxidized extracellular EhCySS. This increase in ROS was blocked by overexpression of mitochondrial thioredoxin-2 (Trx2) in endothelial cells from Trx2-transgenic mice, suggesting that mitochondrial thiol antioxidant status plays a key role in this redox signaling mechanism. Mass spectrometry-based redox proteomics showed that several classes of plasma membrane and cytoskeletal proteins involved in inflammation responded to this redox switch, including vascular cell adhesion molecule, integrins, actin, and several Ras family GTPases. Together, the data show that the proinflammatory effects of oxidized plasma EhCySS are due to a mitochondrial signaling pathway that is mediated through redox control of downstream effector proteins. PMID:19879942

Plasma butyrylcholinesterase regulates ghrelin to control aggression

PubMed Central

Chen, Vicky Ping; Gao, Yang; Geng, Liyi; Parks, Robin J.; Pang, Yuan-Ping; Brimijoin, Stephen

2015-01-01

Ongoing mouse studies of a proposed therapy for cocaine abuse based on viral gene transfer of butyrylcholinesterase (BChE) mutated for accelerated cocaine hydrolysis have yielded surprising effects on aggression. Further investigation has linked these effects to a reduction in circulating ghrelin, driven by BChE at levels ∼100-fold above normal. Tests with human BChE showed ready ghrelin hydrolysis at physiologic concentrations, and multiple low-mass molecular dynamics simulations revealed that ghrelin’s first five residues fit sterically and electrostatically into BChE’s active site. Consistent with in vitro results, male BALB/c mice with high plasma BChE after gene transfer exhibited sharply reduced plasma ghrelin. Unexpectedly, such animals fought less, both spontaneously and in a resident/intruder provocation model. One mutant BChE was found to be deficient in ghrelin hydrolysis. BALB/c mice transduced with this variant retained normal plasma ghrelin levels and did not differ from untreated controls in the aggression model. In contrast, C57BL/6 mice with BChE gene deletion exhibited increased ghrelin and fought more readily than wild-type animals. Collectively, these findings indicate that BChE-catalyzed ghrelin hydrolysis influences mouse aggression and social stress, with potential implications for humans. PMID:25646463

Physics conditions for robust control of tearing modes in a rotating tokamak plasma

NASA Astrophysics Data System (ADS)

Lazzaro, E.; Borgogno, D.; Brunetti, D.; Comisso, L.; Fevrier, O.; Grasso, D.; Lutjens, H.; Maget, P.; Nowak, S.; Sauter, O.; Sozzi, C.; the EUROfusion MST1 Team

2018-01-01

The disruptive collapse of the current sustained equilibrium of a tokamak is perhaps the single most serious obstacle on the path toward controlled thermonuclear fusion. The current disruption is generally too fast to be identified early enough and tamed efficiently, and may be associated with a variety of initial perturbing events. However, a common feature of all disruptive events is that they proceed through the onset of magnetohydrodynamic instabilities and field reconnection processes developing magnetic islands, which eventually destroy the magnetic configuration. Therefore the avoidance and control of magnetic reconnection instabilities is of foremost importance and great attention is focused on the promising stabilization techniques based on localized rf power absorption and current drive. Here a short review is proposed of the key aspects of high power rf control schemes (specifically electron cyclotron heating and current drive) for tearing modes, considering also some effects of plasma rotation. From first principles physics considerations, new conditions are presented and discussed to achieve control of the tearing perturbations by means of high power ({P}{{EC}}≥slant {P}{{ohm}}) in regimes where strong nonlinear instabilities may be driven, such as secondary island structures, which can blur the detection and limit the control of the instabilities. Here we consider recent work that has motivated the search for the improvement of some traditional control strategies, namely the feedback schemes based on strict phase tracking of the propagating magnetic islands.

Suspensions Plasma Spraying of Ceramics with Hybrid Water-Stabilized Plasma Technology

NASA Astrophysics Data System (ADS)

Musalek, Radek; Medricky, Jan; Tesar, Tomas; Kotlan, Jiri; Pala, Zdenek; Lukac, Frantisek; Chraska, Tomas; Curry, Nicholas

2017-01-01

Technology of water-stabilized plasma torch was recently substantially updated through introduction of a so-called hybrid concept that combines benefits of water stabilization and gas stabilization principles. The high-enthalpy plasma provided by the WSP-H ("hybrid") torch may be used for thermal spraying of powders as well as liquid feedstocks with high feed rates. In this study, results from three selected experiments with suspension plasma spraying with WSP-H technology are presented. Possibility of deposition of coatings with controlled microstructures was demonstrated for three different ceramics (YSZ—yttria-stabilized zirconia, YAG—yttrium aluminum garnet and Al2O3) introduced into ethanol-based suspensions. Shadowgraphy was used for optimization of suspension injection and visualization of the liquid fragmentation in the plasma jet. Coatings were deposited onto substrates attached to the rotating carousel with integrated temperature monitoring and air cooling, which provided an excellent reproducibility of the deposition process. Deposition of columnar-like YSZ and dense YAG and Al2O3 coatings was successfully achieved. Deposition efficiency reached more than 50%, as evaluated according to EN ISO 17 836 standard.

Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

NASA Astrophysics Data System (ADS)

Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

2017-04-01

Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(Cdbnd O, Csbnd OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

Combined circulating tumor DNA and protein biomarker-based liquid biopsy for the earlier detection of pancreatic cancers.

PubMed

Cohen, Joshua D; Javed, Ammar A; Thoburn, Christopher; Wong, Fay; Tie, Jeanne; Gibbs, Peter; Schmidt, C Max; Yip-Schneider, Michele T; Allen, Peter J; Schattner, Mark; Brand, Randall E; Singhi, Aatur D; Petersen, Gloria M; Hong, Seung-Mo; Kim, Song Cheol; Falconi, Massimo; Doglioni, Claudio; Weiss, Matthew J; Ahuja, Nita; He, Jin; Makary, Martin A; Maitra, Anirban; Hanash, Samir M; Dal Molin, Marco; Wang, Yuxuan; Li, Lu; Ptak, Janine; Dobbyn, Lisa; Schaefer, Joy; Silliman, Natalie; Popoli, Maria; Goggins, Michael G; Hruban, Ralph H; Wolfgang, Christopher L; Klein, Alison P; Tomasetti, Cristian; Papadopoulos, Nickolas; Kinzler, Kenneth W; Vogelstein, Bert; Lennon, Anne Marie

2017-09-19

The earlier diagnosis of cancer is one of the keys to reducing cancer deaths in the future. Here we describe our efforts to develop a noninvasive blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests for KRAS gene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinomas and 182 control patients without known cancer. KRAS mutations were detected in the plasma of 66 patients (30%), and every mutation found in the plasma was identical to that subsequently found in the patient's primary tumor (100% concordance). The use of KRAS in conjunction with four thresholded protein biomarkers increased the sensitivity to 64%. Only one of the 182 plasma samples from the control cohort was positive for any of the DNA or protein biomarkers (99.5% specificity). This combinatorial approach may prove useful for the earlier detection of many cancer types.

Combining mass spectrometry diagnostic and density functional theory calculations for a better understanding of the plasma polymerization of ethyl lactate.

PubMed

Ligot, S; Guillaume, M; Gerbaux, P; Thiry, D; Renaux, F; Cornil, J; Dubois, P; Snyders, R

2014-04-17

The focus of this work is on the growth mechanism of ethyl lactate-based plasma polymer film (ELPPF) that could be used as barrier coatings. In such an application, the ester density of the plasma polymer has to be controlled to tune the degradation rate of the material. Our strategy consists of correlating the plasma chemistry evaluated by RGA mass spectrometry and understanding, via DFT calculations, the chemistry of the synthesized thin films. The theoretical calculations helped us to understand the plasma chemistry in plasma ON and OFF conditions. From these data it is unambiguously shown that the signal m/z 75 can directly be correlated with the precursor density in the plasma phase. The combination of XPS and chemical derivatization experiments reveal that the ester content in the ELPFF can be tailored from 2 to 18 at. % by decreasing the RF power, which is perfectly correlated with the evolution of the plasma chemistry. Our results also highlight that the ELPPF chemistry, especially the ester content, is affected by the plasma mode of operation (continuous or pulsed discharge, at similar injected mean power) for similar ester content in the plasma. This could be related to different energy conditions at the interface of the growing films that could affect the sticking coefficient of the ester-bearing fragments.

Magnetic nanomotor fabrication by plasma coating method and its biological application

NASA Astrophysics Data System (ADS)

Oksuz, Lutfi; Yurdabak Karaca, Gozde; Uygun, Emre; Uygun Oksuz, Aysegul

2017-10-01

Nano/micro scale motors are exciting research area due to a wide range of application area especially offer considerable promise for the diagnosis and treatment of the diseases. In this scope, the preparation and characterization of Gold (Au)/ Nickel (Ni) nanomotors transport and their applications based on the detection of miRNA-21 will be examined. In addition, magnetic segment Ni which was coated by RF magnetron sputter technique on to the electrochemical synthesized Au nanowire can also be used to focus on the controlled movement and target. We propose a sensitive stable plasma coated magnetic nanomotor-based approach for miRNA-21 detection for simple and cancer diagnosis.

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability.

PubMed

Struzzi, Claudia; Scardamaglia, Mattia; Hemberg, Axel; Petaccia, Luca; Colomer, Jean-François; Snyders, Rony; Bittencourt, Carla

2015-01-01

Grafting of fluorine species on carbon nanostructures has attracted interest due to the effective modification of physical and chemical properties of the starting materials. Various techniques have been employed to achieve a controlled fluorination yield; however, the effect of contaminants is rarely discussed, although they are often present. In the present work, the fluorination of vertically aligned multiwalled carbon nanotubes was performed using plasma treatment in a magnetron sputtering chamber with fluorine diluted in an argon atmosphere with an Ar/F2 ratio of 95:5. The effect of heavily diluted fluorine in the precursor gas mixture is investigated by evaluating the modifications in the nanotube structure and the electronic properties upon plasma treatment. The existence of oxygen-based grafted species is associated with background oxygen species present in the plasma chamber in addition to fluorine. The thermal stability and desorption process of the fluorine species grafted on the carbon nanotubes during the fluorine plasma treatment were evaluated by combining different spectroscopic techniques.

Deposition of Composite LSCF-SDC and SSC-SDC Cathodes by Axial-Injection Plasma Spraying

NASA Astrophysics Data System (ADS)

Harris, Jeffrey; Qureshi, Musab; Kesler, Olivera

2012-06-01

The performance of solid oxide fuel cell cathodes can be improved by increasing the number of electrochemical reaction sites, by controlling microstructures, or by using composite materials that consist of an ionic conductor and a mixed ionic and electronic conductor. LSCF (La0.6Sr0.4Co0.2Fe0.8O3-δ) and SSC (Sm0.5Sr0.5CoO3) cathodes were manufactured by axial-injection atmospheric plasma spraying, and composite cathodes were fabricated by mixing SDC (Ce0.8Sm0.2O1.9) into the feedstock powders. The plasma power was varied by changing the proportion of nitrogen in the plasma gas. The microstructures of cathodes produced with different plasma powers were characterized by scanning electron microscopy and gas permeation measurements. The deposition efficiencies of these cathodes were calculated based on the mass of the sprayed cathode. Particle surface temperatures were measured in-flight to enhance understanding of the relationship between spray parameters, microstructure, and deposition efficiency.

The diverse applications of plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Mukul, E-mail: mukulsharma@acropolis.edu.in; Darwhekar, Gajanan, E-mail: gdarwhekar@acropolis.edu.in; Dubey, Shivani, E-mail: dubeyshivani08@rediffmail.com

Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteriamore » and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.« less

The diverse applications of plasma

NASA Astrophysics Data System (ADS)

Sharma, Mukul; Dubey, Shivani; Darwhekar, Gajanan; Jain, Sudhir Kumar

2015-07-01

Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteria and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.

Crucial issues of multi-beam feed-back control with ECH/ECCD in fusion plasmas

NASA Astrophysics Data System (ADS)

Cirant, S.; Berrino, J.; Gandini, F.; Granucci, G.; Iannone, F.; Lazzaro, E.; D'Antona, G.; Farina, D.; Koppenburg, K.; Nowak, S.; Ramponi, G.

2005-01-01

Proof of principle of feed-back controlled Electron Cyclotron Heating and Current Drive (ECH/ECCD), aiming at automatic limitation (or suppression) of Neoclassical Tearing Modes amplitude, has been achieved in a number of present machines. In addition to Neoclassical Tearing Mode stabilization, more applications of well-localized ECH/ECCD can be envisaged (saw-tooth crash control, current profile control, thermal barrier control, disruption mitigation). However, in order to be able to take a step forward towards the application of these techniques to burning plasmas, some crucial issues should be more deeply analyzed: multi-beam simultaneous action, control of deposition radii rdep, diagnostic of plasma reaction. So far the Electron Cyclotron Emission has been the most important tool to get localized information on plasma response, essential for both rdep and risland recognition, but its use in very hot burning plasmas within automatic control loops should be carefully verified. Assuming that plasma response is appropriately diagnosed, the next matter to be discussed concerns how to control rdep, since all techniques so far used, or proposed (plasma position, toroidal field, mechanical beam steering, gyrotron frequency tuning) have limitations or drawbacks. Finally, simultaneous multiple actions on many actuators (EC beams), concurring to automatic control of one single parameter (e.g. NTM amplitude) might be a challenging task for the controller, particularly in view of the fact that any effect of each beam becomes visible only when it is positioned very close to the right radius. All these interlinked aspects are discussed in the paper.

Autoresonant Control of Elliptical Non-neutral Plasmas

NASA Astrophysics Data System (ADS)

Friedland, Lazar

1999-11-01

It is shown that placing a magnetized non-neutral plasma column in a weak oscillating transverse quadrupolar potential with chirped oscillation frequency allows excitation and control of the ellipticity and rotation phase of the plasma cross section. For a given chirp rate of the driving frequency, the phenomenon has a sharp threshold on the amplitude of the perturbing potential. The effect is analogous to that reported in controlling Kirchhoff vortices in fluid dynamics [1]. The ellipticity of the plasma cross section is manipulated by using autoresonance (nonlinear phase locking) in the system between the ExB drifting plasma particles and adiabatically varying driving potential. A similar idea was used recently in controlling the l=1 diocotron mode in a non-neutral plasma [2]. [1] L. Friedland, Phys. Rev. E59, 4106 (1999). [2] J. Fajans, E. Gilson, and L. Friedland, Phys. Rev. Lett. 82, 4444 (1999).

Energy Confinement Recovery in Low Collisionality ITER Shape Plasmas with Applied Resonant Magnetic Perturbations (RMPs)

NASA Astrophysics Data System (ADS)

Cui, L.; Grierson, B.; Logan, N.; Nazikian, R.

2016-10-01

Application of RMPs to low collisionality (ν*e < 0.4) ITER shape plasmas on DIII-D leads to a rapid reduction in stored energy due to density pumpout that is sometimes followed by a gradual recovery in the plasma stored energy. Understanding this confinement recovery is essential to optimize the confinement of RMP plasmas in present and future devices such as ITER. Transport modeling using TRANSP+TGLF indicates that the core a/LTi is stiff in these plasmas while the ion temperature gradient is much less stiff in the pedestal region. The reduction in the edge density during pumpout leads to an increase in the core ion temperature predicted by TGLF based on experimental data. This is correlated to the increase in the normalized ion heat flux. Transport stiffness in the core combined with an increase in the edge a/LTi results in an increase of the plasma stored energy, consistent with experimental observations. For plasmas where the edge density is controlled using deuterium gas puffs, the effect of the RMP on ion thermal confinement is significantly reduced. Work supported by US DOE Grant DE-FC02-04ER54698 and DE-AC02-09CH11466.

Fabrication of Titanium-Niobium-Zirconium-Tantalium Alloy (TNZT) Bioimplant Components with Controllable Porosity by Spark Plasma Sintering

PubMed Central

Rechtin, Jack; Torresani, Elisa; Ivanov, Eugene; Olevsky, Eugene

2018-01-01

Spark Plasma Sintering (SPS) is used to fabricate Titanium-Niobium-Zirconium-Tantalum alloy (TNZT) powder—based bioimplant components with controllable porosity. The developed densification maps show the effects of final SPS temperature, pressure, holding time, and initial particle size on final sample relative density. Correlations between the final sample density and mechanical properties of the fabricated TNZT components are also investigated and microstructural analysis of the processed material is conducted. A densification model is proposed and used to calculate the TNZT alloy creep activation energy. The obtained experimental data can be utilized for the optimized fabrication of TNZT components with specific microstructural and mechanical properties suitable for biomedical applications. PMID:29364165

Control of surface defects on plasma-MIG hybrid welds in cryogenic aluminum alloys

NASA Astrophysics Data System (ADS)

Lee, Hee-Keun; Chun, Kwang-San; Park, Sang-Hyeon; Kang, Chung-Yun

2015-07-01

Lately, high production rate welding processes for Al alloys, which are used as LNG FPSO cargo containment system material, have been developed to overcome the limit of installation and high rework rates. In particular, plasma-metal inert gas (MIG) hybrid (PMH) welding can be used to obtain a higher deposition rate and lower porosity, while facilitating a cleaning effect by preheating and post heating the wire and the base metal. However, an asymmetric undercut and a black-colored deposit are created on the surface of PMH weld in Al alloys. For controlling the surface defect formation, the wire feeding speed and nozzle diameter in the PMH weld was investigated through arc phenomena with high-speed imaging and metallurgical analysis.

Initial operation of the NSTX-Upgrade real-time velocity diagnostic

DOE PAGES

Podestà, M.; Bell, R. E.

2016-11-03

A real-time velocity (RTV) diagnostic based on active charge-exchange recombination spectroscopy is now operational on the National Spherical Torus Experiment-Upgrade (NSTX-U) spherical torus (Menard et al 2012 Nucl. Fusion 52 083015). We designed the system in order to supply plasma velocity data in real time to the NSTX-U plasma control system, as required for the implementation of toroidal rotation control. Our measurements are available from four radii at a maximum sampling frequency of 5 kHz. Post-discharge analysis of RTV data provides additional information on ion temperature, toroidal velocity and density of carbon impurities. Furthermore, examples of physics studies enabled bymore » RTV measurements from initial operations of NSTX-U are discussed.« less

Feedback system for divertor impurity seeding based on real-time measurements of surface heat flux in the Alcator C-Mod tokamak

NASA Astrophysics Data System (ADS)

Brunner, D.; Burke, W.; Kuang, A. Q.; LaBombard, B.; Lipschultz, B.; Wolfe, S.

2016-02-01

Mitigation of the intense heat flux to the divertor is one of the outstanding problems in fusion energy. One technique that has shown promise is impurity seeding, i.e., the injection of low-Z gaseous impurities (typically N2 or Ne) to radiate and dissipate the power before it arrives to the divertor target plate. To this end, the Alcator C-Mod team has created a first-of-its-kind feedback system to control the injection of seed gas based on real-time surface heat flux measurements. Surface thermocouples provide real-time measurements of the surface temperature response to the plasma heat flux. The surface temperature measurements are inputted into an analog computer that "solves" the 1-D heat transport equation to deliver accurate, real-time signals of the surface heat flux. The surface heat flux signals are sent to the C-Mod digital plasma control system, which uses a proportional-integral-derivative (PID) algorithm to control the duty cycle demand to a pulse width modulated piezo valve, which in turn controls the injection of gas into the private flux region of the C-Mod divertor. This paper presents the design and implementation of this new feedback system as well as initial results using it to control divertor heat flux.

Feedback system for divertor impurity seeding based on real-time measurements of surface heat flux in the Alcator C-Mod tokamak.

PubMed

Brunner, D; Burke, W; Kuang, A Q; LaBombard, B; Lipschultz, B; Wolfe, S

2016-02-01

Mitigation of the intense heat flux to the divertor is one of the outstanding problems in fusion energy. One technique that has shown promise is impurity seeding, i.e., the injection of low-Z gaseous impurities (typically N2 or Ne) to radiate and dissipate the power before it arrives to the divertor target plate. To this end, the Alcator C-Mod team has created a first-of-its-kind feedback system to control the injection of seed gas based on real-time surface heat flux measurements. Surface thermocouples provide real-time measurements of the surface temperature response to the plasma heat flux. The surface temperature measurements are inputted into an analog computer that "solves" the 1-D heat transport equation to deliver accurate, real-time signals of the surface heat flux. The surface heat flux signals are sent to the C-Mod digital plasma control system, which uses a proportional-integral-derivative (PID) algorithm to control the duty cycle demand to a pulse width modulated piezo valve, which in turn controls the injection of gas into the private flux region of the C-Mod divertor. This paper presents the design and implementation of this new feedback system as well as initial results using it to control divertor heat flux.

Towards Attosecond High-Energy Electron Bunches: Controlling Self-Injection in Laser-Wakefield Accelerators Through Plasma-Density Modulation

NASA Astrophysics Data System (ADS)

Tooley, M. P.; Ersfeld, B.; Yoffe, S. R.; Noble, A.; Brunetti, E.; Sheng, Z. M.; Islam, M. R.; Jaroszynski, D. A.

2017-07-01

Self-injection in a laser-plasma wakefield accelerator is usually achieved by increasing the laser intensity until the threshold for injection is exceeded. Alternatively, the velocity of the bubble accelerating structure can be controlled using plasma density ramps, reducing the electron velocity required for injection. We present a model describing self-injection in the short-bunch regime for arbitrary changes in the plasma density. We derive the threshold condition for injection due to a plasma density gradient, which is confirmed using particle-in-cell simulations that demonstrate injection of subfemtosecond bunches. It is shown that the bunch charge, bunch length, and separation of bunches in a bunch train can be controlled by tailoring the plasma density profile.

Effects of the herbicide atrazine on Ambystoma tigrinum metamorphosis: duration, larval growth, and hormonal response

USGS Publications Warehouse

Larson, Diane L.; McDonald, Susan; Hamilton, Steven J.; Fivizzani, Albert J.; Newton, Wesley E.

1998-01-01

We exposed larval tiger salamanders (Ambystoma tigrinum) reared in the laboratory from eggs collected from a prairie wetland in North Dakota to three concentrations of atrazine (0, 75, and 250 i??g/L) in a static renewal test to determine the pesticide's effect on (1) plasma corticosterone and thyroxine concentrations, (2) larval size, and (3) days-to-stage at stages 2 and 4 of metamorphic climax. We found significant effects of atrazine on each of these response variables. Plasma thyroxine was elevated in both atrazine-exposed groups compared to the control group; plasma corticosterone was depressed in the 75 i??g/L treatment compared with both the control and 250 i??g/L treatment. Larvae exposed to 75 i??g/L atrazine reached stage 4 later, but at a size and weight comparable to the control group. By contrast, larvae in the 250 i??g/L treatment progressed to stage 4 at the same time but at a smaller size and lower weight than larvae in the control group. These results indicate that the herbicide has the potential to influence tiger salamander life history. We present a model consistent with our results, whereby corticosterone and thyroxine interact to regulate metamorphosis of tiger salamanders based on nutrient assimilation and adult fitness

Reduced-Order Model Based Feedback Control For Modified Hasegawa-Wakatani Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goumiri, I. R.; Rowley, C. W.; Ma, Z.

2013-01-28

In this work, the development of model-based feedback control that stabilizes an unstable equilibrium is obtained for the Modi ed Hasegawa-Wakatani (MHW) equations, a classic model in plasma turbulence. First, a balanced truncation (a model reduction technique that has proven successful in ow control design problems) is applied to obtain a low dimensional model of the linearized MHW equation. Then a modelbased feedback controller is designed for the reduced order model using linear quadratic regulators (LQR). Finally, a linear quadratic gaussian (LQG) controller, which is more resistant to disturbances is deduced. The controller is applied on the non-reduced, nonlinear MHWmore » equations to stabilize the equilibrium and suppress the transition to drift-wave induced turbulence.« less

Integrated Computer Controlled Glow Discharge Tube

NASA Astrophysics Data System (ADS)

Kaiser, Erik; Post-Zwicker, Andrew

2002-11-01

An "Interactive Plasma Display" was created for the Princeton Plasma Physics Laboratory to demonstrate the characteristics of plasma to various science education outreach programs. From high school students and teachers, to undergraduate students and visitors to the lab, the plasma device will be a key component in advancing the public's basic knowledge of plasma physics. The device is fully computer controlled using LabVIEW, a touchscreen Graphical User Interface [GUI], and a GPIB interface. Utilizing a feedback loop, the display is fully autonomous in controlling pressure, as well as in monitoring the safety aspects of the apparatus. With a digital convectron gauge continuously monitoring pressure, the computer interface analyzes the input signals, while making changes to a digital flow controller. This function works independently of the GUI, allowing the user to simply input and receive a desired pressure; quickly, easily, and intuitively. The discharge tube is a 36" x 4"id glass cylinder with 3" side port. A 3000 volt, 10mA power supply, is used to breakdown the plasma. A 300 turn solenoid was created to demonstrate the magnetic pinching of a plasma. All primary functions of the device are controlled through the GUI digital controllers. This configuration allows for operators to safely control the pressure (100mTorr-1Torr), magnetic field (0-90Gauss, 7amps, 10volts), and finally, the voltage applied across the electrodes (0-3000v, 10mA).

The alkaline tide and ammonia excretion after voluntary feeding in freshwater rainbow trout.

PubMed

Bucking, Carol; Wood, Chris M

2008-08-01

We investigated the potential acid-base and nitrogenous waste excretion challenges created by voluntary feeding in freshwater rainbow trout, with particular focus on the possible occurrence of an alkaline tide (a metabolic alkalosis created by gastric HCl secretion during digestion). Plasma metabolites (glucose, urea and ammonia) were measured at various time points before and after voluntary feeding to satiation (approximately 5% body mass meal of dry commercial pellets), as was the net flux of ammonia and titratable alkalinity to the water from unfed and fed fish. Arterial blood, sampled by indwelling catheter, was examined for post-prandial effects on pH, plasma bicarbonate and plasma CO2 tension. There was no significant change in plasma glucose or urea concentrations following feeding, whereas plasma ammonia transiently increased, peaking at threefold above resting values at 12 h after the meal and remaining elevated for 24 h. The increased plasma ammonia was correlated with an increase in net ammonia excretion to the water, with fed fish significantly elevating their net ammonia excretion two- to threefold between 12 and 48 h post feeding. These parameters did not change in unfed control fish. Fed fish likewise increased the net titratable base flux to the water by approximately threefold, which resulted in a transition from a small net acid flux seen in unfed fish to a large net base flux in fed fish. Over 48 h, this resulted in a net excretion of 13 867 micromol kg(-1) more base to the external water than in unfed fish. The arterial blood exhibited a corresponding rise in pH (between 6 and 12 h) and plasma bicarbonate (between 3 and 12 h) following feeding; however, no respiratory compensation was observed, as PaCO2 remained constant. Overall, there was evidence of numerous challenges created by feeding in a freshwater teleost fish, including the occurrence of an alkaline tide, and its compensation by excretion of base to the external water. The possible influence of feeding ecology and environmental salinity on these challenges, as well as discrepancies in the literature, are discussed.

Relationships between extraction and metabolism of glucose, blood flow, and tissue blood volume in regions of rat brain.

PubMed

Cremer, J E; Cunningham, V J; Seville, M P

1983-09-01

Studies were made on the relationships between the rate of glucose metabolism, the transport of glucose between plasma and brain, cerebral blood flow, and blood content. Conscious control rats were compared with rats with intense tremors induced with cismethrin. The influence of plasma glucose concentration was studied by fasting some animals overnight prior to the induction of tremors. Mean plasma glucose was 8.83 mM in controls, 12.57 mM in fed rats with tremors, and 4.94 mM in rats fasted overnight prior to induction of tremors. Of 12 brain regions studied, nine showed an increased rate of glucose utilization in both fed and fasted trembling rats. Cerebellum had the highest percentage increase (200%). Rates of unidirectional glucose influx in fed trembling rats were significantly greater than those in controls in eight regions. In fasted animals, rates were the same as in controls, except in cerebellum, where it was 1.6 times higher. These high rates of glucose influx at low plasma glucose concentrations were indicative of a change in kinetic parameters of glucose transport. Unidirectional glucose influx rates were transformed to estimates of maximal transport rates (Tmax), based on the Michaelis-Menten equation. Average plasma glucose concentrations in regional capillaries (c) were calculated and shown to be maintained at values close to arterial plasma glucose concentrations (Ca), in all brain regions of each group. In trembling rats, Tmax for each brain region was higher than that in controls. In fasted rats with tremors, Tmax was higher in several brain regions than in fed rats. Tmax in cerebellum was 3.37, 4.71, and 7.89 mumol g-1 min-1 in control, fed trembling, and fasted trembling rats, respectively. Blood flow increased significantly in all regions in rats with tremors and was higher in fasted than in fed animals. There was only a weak correlation between blood flow and Tmax. Blood content of several regions increased in rats with tremors, and there was a strong correlation between Tmax and tissue blood volume. Results are consistent with localized regulatory links between blood flow, capillary surface area, and glucose transport in response to metabolic demand and hypoglycaemia. These involve changes in the linear velocity of blood through capillaries and in the extent of capillary recruitment.

Fluorocarbon assisted atomic layer etching of SiO 2 and Si using cyclic Ar/C 4F 8 and Ar/CHF 3 plasma

DOE PAGES

Metzler, Dominik; Li, Chen; Engelmann, Sebastian; ...

2015-11-11

The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C 4F 8 ALE based on steady-state Ar plasma in conjunction with periodic, precise C 4F 8 injection and synchronized plasma-based low energy Ar + ion bombardment has been established for SiO 2. 1 In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF 3 as a precursor is examined and compared to C 4F 8. CHF 3 is shown to enablemore » selective SiO 2/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and X-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. As a result, plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less

Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

PubMed Central

Arosalo, Bela M; Raekallio, Marja; Rajamäki, Minna; Holopainen, Elina; Kastevaara, Tuulia; Salonen, Hanna; Sankari, Satu

2007-01-01

Background The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9) activity, alkaline phosphatase/creatinine (U-AP/Cr) and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr) ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr) ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5) were compared to healthy stallions (n = 7) that came for castration. Blood and urine samples were collected. MMP gelatinolytic activity was measured by zymography. Results We found out that horses with colic had significantly higher urinary MMP-9 complex and proMMP-9 activities than horses in the control group. Colic horses also had higher plasma MMP-2 activity than the control horses. Serum creatinine, although within reference range, was significantly higher in the colic horses than in the control group. There was no significant increase in urinary alkaline phosphatase, gamma-glutamyltranspeptidase or total proteins in the colic horses compared to the control group. A human cystatin-C test (Dako Cytomation latex immunoassay® based on turbidimetry) did not cross react with equine cystatin-C. Conclusion The results indicate that plasma MMP-2 may play a role in the pathogenesis of equine colic and urinary MMP-9 in equine kidney damage. PMID:17244354

Proteomic signatures in plasma during early acute renal allograft rejection.

PubMed

Freue, Gabriela V Cohen; Sasaki, Mayu; Meredith, Anna; Günther, Oliver P; Bergman, Axel; Takhar, Mandeep; Mui, Alice; Balshaw, Robert F; Ng, Raymond T; Opushneva, Nina; Hollander, Zsuzsanna; Li, Guiyun; Borchers, Christoph H; Wilson-McManus, Janet; McManus, Bruce M; Keown, Paul A; McMaster, W Robert

2010-09-01

Acute graft rejection is an important clinical problem in renal transplantation and an adverse predictor for long term graft survival. Plasma biomarkers may offer an important option for post-transplant monitoring and permit timely and effective therapeutic intervention to minimize graft damage. This case-control discovery study (n = 32) used isobaric tagging for relative and absolute protein quantification (iTRAQ) technology to quantitate plasma protein relative concentrations in precise cohorts of patients with and without biopsy-confirmed acute rejection (BCAR). Plasma samples were depleted of the 14 most abundant plasma proteins to enhance detection sensitivity. A total of 18 plasma proteins that encompassed processes related to inflammation, complement activation, blood coagulation, and wound repair exhibited significantly different relative concentrations between patient cohorts with and without BCAR (p value <0.05). Twelve proteins with a fold-change >or=1.15 were selected for diagnostic purposes: seven were increased (titin, lipopolysaccharide-binding protein, peptidase inhibitor 16, complement factor D, mannose-binding lectin, protein Z-dependent protease and beta(2)-microglobulin) and five were decreased (kininogen-1, afamin, serine protease inhibitor, phosphatidylcholine-sterol acyltransferase, and sex hormone-binding globulin) in patients with BCAR. The first three principal components of these proteins showed clear separation of cohorts with and without BCAR. Performance improved with the inclusion of sequential proteins, reaching a primary asymptote after the first three (titin, kininogen-1, and lipopolysaccharide-binding protein). Longitudinal monitoring over the first 3 months post-transplant based on ratios of these three proteins showed clear discrimination between the two patient cohorts at time of rejection. The score then declined to baseline following treatment and resolution of the rejection episode and remained comparable between cases and controls throughout the period of quiescent follow-up. Results were validated using ELISA where possible, and initial cross-validation estimated a sensitivity of 80% and specificity of 90% for classification of BCAR based on a four-protein ELISA classifier. This study provides evidence that protein concentrations in plasma may provide a relevant measure for the occurrence of BCAR and offers a potential tool for immunologic monitoring.

Proteomic Signatures in Plasma during Early Acute Renal Allograft Rejection*

PubMed Central

Freue, Gabriela V. Cohen; Sasaki, Mayu; Meredith, Anna; Günther, Oliver P.; Bergman, Axel; Takhar, Mandeep; Mui, Alice; Balshaw, Robert F.; Ng, Raymond T.; Opushneva, Nina; Hollander, Zsuzsanna; Li, Guiyun; Borchers, Christoph H.; Wilson-McManus, Janet; McManus, Bruce M.; Keown, Paul A.; McMaster, W. Robert

2010-01-01

Acute graft rejection is an important clinical problem in renal transplantation and an adverse predictor for long term graft survival. Plasma biomarkers may offer an important option for post-transplant monitoring and permit timely and effective therapeutic intervention to minimize graft damage. This case-control discovery study (n = 32) used isobaric tagging for relative and absolute protein quantification (iTRAQ) technology to quantitate plasma protein relative concentrations in precise cohorts of patients with and without biopsy-confirmed acute rejection (BCAR). Plasma samples were depleted of the 14 most abundant plasma proteins to enhance detection sensitivity. A total of 18 plasma proteins that encompassed processes related to inflammation, complement activation, blood coagulation, and wound repair exhibited significantly different relative concentrations between patient cohorts with and without BCAR (p value <0.05). Twelve proteins with a fold-change ≥1.15 were selected for diagnostic purposes: seven were increased (titin, lipopolysaccharide-binding protein, peptidase inhibitor 16, complement factor D, mannose-binding lectin, protein Z-dependent protease and β2-microglobulin) and five were decreased (kininogen-1, afamin, serine protease inhibitor, phosphatidylcholine-sterol acyltransferase, and sex hormone-binding globulin) in patients with BCAR. The first three principal components of these proteins showed clear separation of cohorts with and without BCAR. Performance improved with the inclusion of sequential proteins, reaching a primary asymptote after the first three (titin, kininogen-1, and lipopolysaccharide-binding protein). Longitudinal monitoring over the first 3 months post-transplant based on ratios of these three proteins showed clear discrimination between the two patient cohorts at time of rejection. The score then declined to baseline following treatment and resolution of the rejection episode and remained comparable between cases and controls throughout the period of quiescent follow-up. Results were validated using ELISA where possible, and initial cross-validation estimated a sensitivity of 80% and specificity of 90% for classification of BCAR based on a four-protein ELISA classifier. This study provides evidence that protein concentrations in plasma may provide a relevant measure for the occurrence of BCAR and offers a potential tool for immunologic monitoring. PMID:20501940

Pre-Ionization Controlled Laser Plasma Formation for Ignition Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shneider, Mikhail

The presented research explored new physics and ignition schemes based on laser induced plasmas that are fundamentally distinct from past laser ignition research focused on single laser pulses. Specifically, we consider the use of multiple laser pulses where the first pulse provides pre-ionization allowing controlled absorption of the second pulse. In this way, we can form tailored laser plasmas in terms of their ionization fraction, gas temperature (e.g. to achieve elevated temperature of ~2000 K ideally suited for an ignition source), reduced energy loss to shock waves and radiation, and large kernel size (e.g. length ~1-10 cm). The proposed researchmore » included both experimental and modeling efforts, at Colorado State University, Princeton University and University of Tennessee, towards the basic science of the new laser plasma approach with emphasis on tailoring the plasmas to practical propulsion systems. Experimental results (CSU) show that the UV beam produces a pre-ionized volume which assists in breakdown of the NIR beam, leading to reduction in NIR breakdown threshold by factor of >2. Numerical modeling is performed to examine the ionization and breakdown of both beams. The main theoretical and computational parts of the work were done at Princeton University. The modeled breakdown threshold of the NIR, including assist by pre-ionization, is in reasonable agreement with the experimental results.« less

Sex Differences in Plasma Prolactin Response to Tryptophan in Chronic Fatigue Syndrome Patients With and Without Comorbid Fibromyalgia

PubMed Central

Weaver, Shelley A.; Janal, Malvin N.; Aktan, Nadine; Ottenweller, John E.

2010-01-01

Abstract Background Some think chronic fatigue syndrome (CFS) and fibromyalgia (FM) are variants of the same illness process. This would imply that CFS patients with and without comorbid FM have similar biological underpinnings. To test this, we compared serotonergic-based responses, plasma prolactin (PRL), and self-reported measures of fatigue to intravenous infusion of tryptophan among patients with CFS alone, CFS + FM, and healthy controls. Methods Men and women with CFS alone or CFS + FM and healthy subjects, none with current major depressive disorder (MDD), were given 120 mg of l-tryptophan per kg lean body mass intravenously (i.v.). Before and after tryptophan infusion, blood samples were collected, and plasma PRL, tryptophan, and kynurenine concentrations were determined. Results Women with CFS alone, but not CFS + FM, showed upregulated plasma PRL responses compared with controls. There were no differences among groups of men. Plasma tryptophan and kynurenine concentrations did not differ among groups. Conclusions These results indicate that women with CFS alone have upregulated serotonergic tone that is not seen in those with comorbid FM. The lack of effect in men suggests a mechanism that might explain, in part, the increased prevalence of CFS in women. The data support the interpretation that CFS in women is a different illness from FM. PMID:20384451

Ripple formation on Si surfaces during plasma etching in Cl2

NASA Astrophysics Data System (ADS)

Nakazaki, Nobuya; Matsumoto, Haruka; Sonobe, Soma; Hatsuse, Takumi; Tsuda, Hirotaka; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

2018-05-01

Nanoscale surface roughening and ripple formation in response to ion incidence angle has been investigated during inductively coupled plasma etching of Si in Cl2, using sheath control plates to achieve the off-normal ion incidence on blank substrate surfaces. The sheath control plate consisted of an array of inclined trenches, being set into place on the rf-biased electrode, where their widths and depths were chosen in such a way that the sheath edge was pushed out of the trenches. The distortion of potential distributions and the consequent deflection of ion trajectories above and in the trenches were then analyzed based on electrostatic particle-in-cell simulations of the plasma sheath, to evaluate the angular distributions of ion fluxes incident on substrates pasted on sidewalls and/or at the bottom of the trenches. Experiments showed well-defined periodic sawtooth-like ripples with their wave vector oriented parallel to the direction of ion incidence at intermediate off-normal angles, while relatively weak corrugations or ripplelike structures with the wave vector perpendicular to it at high off-normal angles. Possible mechanisms for the formation of surface ripples during plasma etching are discussed with the help of Monte Carlo simulations of plasma-surface interactions and feature profile evolution. The results indicate the possibility of providing an alternative to ion beam sputtering for self-organized formation of ordered surface nanostructures.

[The changes of ghrelin, growth hormone, growth hormone releasing hormone and their clinical significances in patients with chronic obstructive pulmonary disease].

PubMed

Xu, Zhi-song; Bao, Zi-yu; Wang, Zhi-ying; Yang, Guo-jun; Zhu, Dong-fang; Zhang, Li; Tan, Rong-mei

2012-07-01

To investigate the changes of plasma ghrelin, growth hormone (GH) and growth hormone releasing hormone (GHRH) and gastric ghrelin in patients with chronic obstructive pulmonary disease (COPD) and to explore their clinical significances. Plasma ghrelin, GH, GHRH, TNFα, IL-6 and C reactive protein (CRP) were measured in 40 COPD patients and 20 controls with chronic bronchitis. Correlated factors of plasma ghrelin, TNFα, IL-6, CRP were analyzed. Body composition was assessed with bioelectrical impedance analysis. The expression of gastric ghrelin in patients with COPD was detected. Plasma ghrelin was higher in the underweight patients than in the normal weight patients and in the controls [(1.78 ± 0.46) ng/L, (1.39 ± 0.46) ng/L, (1.36 ± 0.39) ng/L, respectively]. Plasma GH was lower in the underweight patients than in the normal weight patients and in the controls [(4.12 ± 0.83) µg/L, (5.17 ± 0.72)µg/L, (6.49 ± 1.13) µg/L, respectively]. Plasma GHRH was lower in the underweight patients than in the normal weight patients and in the controls [(20.43 ± 4.41) ng/L, (23.47 ± 3.97) ng/L, (27.48 ± 10.06) ng/L, respectively]. Plasma ghrelin was higher in the underweight patients than in the controls (P < 0.01). Plasma ghrelin was higher in the underweight patients than in the normal weight patients with COPD. Plasma ghrelin (log transformed) was negatively correlated with BMI and percentage of body fat in the COPD patients. Plasma GHRH was positively correlated with ghrelin in the underweight patients (r = 0.515, P < 0.05), while no correlation was found between plasma GH and ghrelin in the underweight patients (r = 0.415, P > 0.05). Plasma ghrelin was positively correlated with TNFα and IL-6 in the underweight patients. The gastric expression of ghrelin showed no evident difference between the patients with COPD and the controls. The plasma GH in COPD patients may not be correlated with ghrelin. The plasma ghrelin level may be a useful indicator for malnutrition in COPD patients. Plasma ghrelin might be involved in the pathogenesis of CODP by affecting the body energy metabolism.

Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow

NASA Astrophysics Data System (ADS)

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

2015-11-01

A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.

Plasma Polypyrrole Coated Hybrid Composites with Improved Mechanical and Electrical Properties for Aerospace Applications

NASA Astrophysics Data System (ADS)

Yavuz, Hande; Bai, Jinbo

2018-06-01

This paper deals with the dielectric barrier discharge assisted continuous plasma polypyrrole deposition on CNT-grafted carbon fibers for conductive composite applications. The simultaneous effects of three controllable factors have been studied on the electrical resistivity (ER) of these two material systems based on multivariate experimental design methodology. A posterior probability referring to Benjamini-Hochberg (BH) false discovery rate was explored as multiple testing corrections of the t-test p values. BH significance threshold of 0.05 was produced truly statistically significant coefficients to describe ER of two material systems. A group of plasma modified samples was chosen to be used for composite manufacturing to drive an assessment of interlaminar shear properties under static loading. Transversal and longitudinal electrical resistivity (DC, ω =0) of composite samples were studied to compare both the effects of CNT grafting and plasma modification on ER of resultant composites.

Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demaurex, Bénédicte, E-mail: benedicte.demaurex@epfl.ch; Bartlome, Richard; Seif, Johannes P.

2014-08-07

Low-temperature (≤200 °C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-enhanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only frommore » the growth conditions but also from unintentional contamination of the reactor. Based on our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.« less

Plasma Polypyrrole Coated Hybrid Composites with Improved Mechanical and Electrical Properties for Aerospace Applications

NASA Astrophysics Data System (ADS)

Yavuz, Hande; Bai, Jinbo

2017-09-01

This paper deals with the dielectric barrier discharge assisted continuous plasma polypyrrole deposition on CNT-grafted carbon fibers for conductive composite applications. The simultaneous effects of three controllable factors have been studied on the electrical resistivity (ER) of these two material systems based on multivariate experimental design methodology. A posterior probability referring to Benjamini-Hochberg (BH) false discovery rate was explored as multiple testing corrections of the t-test p values. BH significance threshold of 0.05 was produced truly statistically significant coefficients to describe ER of two material systems. A group of plasma modified samples was chosen to be used for composite manufacturing to drive an assessment of interlaminar shear properties under static loading. Transversal and longitudinal electrical resistivity (DC, ω =0) of composite samples were studied to compare both the effects of CNT grafting and plasma modification on ER of resultant composites.

Identification of a localized core mode in a helicon plasma

NASA Astrophysics Data System (ADS)

Green, Daniel A.; Chakraborty Thakur, Saikat; Tynan, George R.; Light, Adam D.

2017-10-01

We present imaging measurements of a newly observed mode in the core of the Controlled Shear Decorrelation Experiment - Upgrade (CSDX-U). CSDX-U is a well-characterized linear machine producing dense plasmas relevant to the tokamak edge (Te 3 eV, ne 1013 /cc). Typical fluctuations are dominated by electron drift waves, with evidence for Kelvin-Helmholtz vortices appearing near the plasma edge. A new mode has been observed using high-speed imaging that appears at high magnetic field strengths and is confined to the inner third of the plasma column. A cross-spectral phase technique allows direct visualization of dominant spatial structures as a function of frequency. Experimental dispersion curve estimates are constructed from imaging data alone, and allow direct comparison of theoretical dispersion relations to the observed mode. We present preliminary identification of the mode based on its dispersion curve, and compare the results with electrostatic probe measurements.

Post-breakdown secondary discharges at the electrode/dielectric interface of a cylindrical barrier discharge

NASA Astrophysics Data System (ADS)

Carman, Robert; Ward, Barry; Kane, Deborah

2011-10-01

The electrical breakdown characteristics of a double-walled cylindrical dielectric barrier discharge (DBD) lamp with a neon buffer gas under pulsed voltage excitation have been investigated. Following the formation of plasma in the main discharge gap, we have observed secondary breakdown phenomena at the inner and outer mesh electrode/dielectric interfaces under specific operating conditions. Plasma formation at these interfaces is investigated by monitoring the Ozone production rate in controlled flows of ultra high purity oxygen together with the overall electrical voltage-charge characteristics of the lamp. The results show that this secondary breakdown only occurs after the main discharge plasma has been established, and that significant electrical power may be dissipated in generating these spurious secondary plasmas. The results are important with regards to optimising the design and identifying efficient operating regimes of DBD based devices that employ mesh-type or wire/strip electrodes.

A Comparison of Atomic Oxygen Degradation in Low Earth Orbit and in a Plasma Etcher

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline A.; Park, Gloria

1997-01-01

In low Earth orbit (LEO) significant degradation of certain materials occurs from exposure to atomic oxygen (AO). Orbital opportunities to study this degradation for specific materials are limited and expensive. While plasma etchers are commonly used in ground-based studies because of their low cost and convenience, the environment produced in an etcher chamber differs greatly from the LEO environment. Because of the differences in environment, the validity of using etcher data has remained an open question. In this paper, degradation data for 22 materials from the orbital experiment Evaluation of Oxygen Interaction with Materials (EOIM-3) are compared with data from EOIM-3 control specimens exposed in a typical plasma etcher. This comparison indicates that, when carefully considered, plasma etcher results can produce order-of-magnitude estimates of orbital degradation. This allows the etcher to be used to screen unacceptable materials from further, more expensive tests.

Impact of toroidal and poloidal mode spectra on the control of non-axisymmetric fields in tokamaks

NASA Astrophysics Data System (ADS)

Lanctot, Matthew J.

2016-10-01

In several tokamaks, non-axisymmetric magnetic field studies show applied n=2 fields can lead to disruptive n=1 locked modes, suggesting nonlinear mode coupling. A multimode plasma response to n=2 fields can be observed in H-mode plasmas, in contrast to the single-mode response found in Ohmic plasmas. These effects highlight a role for n >1 error field correction in disruption avoidance, and identify additional degrees of freedom for 3D field optimization at high plasma pressure. In COMPASS, EAST, and DIII-D Ohmic plasmas, n=2 magnetic reconnection thresholds in otherwise stable discharges are readily accessed at edge safety factors q 3 and low density. Similar to previous studies, the thresholds are correlated with the ``overlap'' field for the dominant linear ideal MHD plasma mode calculated with the IPEC code. The overlap field measures the plasma-mediated coupling of the external field to the resonant field. Remarkably, the critical overlap fields are similar for n=1 and 2 fields with m >nq fields dominating the drive for resonant fields. Complementary experiments in RFX-Mod show fields with m 1 control, including the need for multiple rows of coils to control selected plasma parameters for specific functions (e.g., rotation control or ELM suppression). Optimal multi-harmonic (n=1 and n=2) error field control may be achieved using control algorithms that continuously respond to time-varying 3D field sources and plasma parameters. Supported by the US DOE under DE-FC02-04ER54698.

Blood-based protein biomarkers for diagnosis of Alzheimer disease.

PubMed

Doecke, James D; Laws, Simon M; Faux, Noel G; Wilson, William; Burnham, Samantha C; Lam, Chiou-Peng; Mondal, Alinda; Bedo, Justin; Bush, Ashley I; Brown, Belinda; De Ruyck, Karl; Ellis, Kathryn A; Fowler, Christopher; Gupta, Veer B; Head, Richard; Macaulay, S Lance; Pertile, Kelly; Rowe, Christopher C; Rembach, Alan; Rodrigues, Mark; Rumble, Rebecca; Szoeke, Cassandra; Taddei, Kevin; Taddei, Tania; Trounson, Brett; Ames, David; Masters, Colin L; Martins, Ralph N

2012-10-01

To identify plasma biomarkers for the diagnosis of Alzheimer disease (AD). Baseline plasma screening of 151 multiplexed analytes combined with targeted biomarker and clinical pathology data. General community-based, prospective, longitudinal study of aging. A total of 754 healthy individuals serving as controls and 207 participants with AD from the Australian Imaging Biomarker and Lifestyle study (AIBL) cohort with identified biomarkers that were validated in 58 healthy controls and 112 individuals with AD from the Alzheimer Disease Neuroimaging Initiative (ADNI) cohort. A biomarker panel was identified that included markers significantly increased (cortisol, pancreatic polypeptide, insulinlike growth factor binding protein 2, β(2) microglobulin, vascular cell adhesion molecule 1, carcinoembryonic antigen, matrix metalloprotein 2, CD40, macrophage inflammatory protein 1α, superoxide dismutase, and homocysteine) and decreased (apolipoprotein E, epidermal growth factor receptor, hemoglobin, calcium, zinc, interleukin 17, and albumin) in AD. Cross-validated accuracy measures from the AIBL cohort reached a mean (SD) of 85% (3.0%) for sensitivity and specificity and 93% (3.0) for the area under the receiver operating characteristic curve. A second validation using the ADNI cohort attained accuracy measures of 80% (3.0%) for sensitivity and specificity and 85% (3.0) for area under the receiver operating characteristic curve. This study identified a panel of plasma biomarkers that distinguish individuals with AD from cognitively healthy control subjects with high sensitivity and specificity. Cross-validation within the AIBL cohort and further validation within the ADNI cohort provides strong evidence that the identified biomarkers are important for AD diagnosis.

Plasma lipids, lipoproteins, and triglyceride turnover in eu- and hypo-thyroid rats and rats on a hypocaloric diet.

PubMed

Dory, L; Krause, B R; Roheim, P S

1981-08-01

Lipid and lipoprotein concentration, and triglyceride turnover were studied in control, thyroidectomized, and pair-fed control rats (pair-fed to match the food intake of the thyroidectomized rats). Thyroidectomy induced a significant increase in plasma cholesterol (and low density lipoprotein) concentrations and a decrease in plasma triglyceride (and very low density lipoprotein) concentrations. Changes in similar direction but of smaller magnitude were observed in the plasma of the pair-fed control rats. To further investigate triglyceride metabolism in these three groups of animals, triglyceride turnover was studied in fasted, unrestrained, and unanesthetized rats, following injection of [2-3H]glycerol. Peak incorporation of [2-3H]glycerol into plasma triglyceride occurred in all three groups of animals at 25 min after precursor administration, although the maximal incorporation was substantially lower in the thyroidectomized group than in either of the control groups. Thereafter, plasma triglyceride radioactivity decayed monoexponentially with a half-life of 24 +/- 1 min for both normal and pair-fed control rats, compared with the half-life of 41 +/- 3 min observed in the thyroidectomized rats. The calculated apparent fractional catabolic rates were thus 0.029 min-1 for both control groups and only 0.017 min-1 for the thyroidectomized animals. The apparent total catabolic rates of plasma triglyceride were 299 +/- 11, 138 +/- 11, and 48 +/- 4 micrograms triglyceride . min-1 for the normal controls, pair-fed controls, and thyroidectomized rats, respectively. These data further emphasize the importance of thyroid hormones in regulating plasma lipid and lipoprotein metabolism and, specifically, indicate that hypothyroidism results in a reduction of triglyceride secretion into, and the removal from, circulation. Furthermore, evidence was presented that the decreased caloric intake of the hypothyroid animals cannot, in itself, account for this observation.

Plasma biomarkers associated with the apolipoprotein E genotype and Alzheimer disease.

PubMed

Soares, Holly D; Potter, William Z; Pickering, Eve; Kuhn, Max; Immermann, Frederick W; Shera, David M; Ferm, Mats; Dean, Robert A; Simon, Adam J; Swenson, Frank; Siuciak, Judith A; Kaplow, June; Thambisetty, Madhav; Zagouras, Panayiotis; Koroshetz, Walter J; Wan, Hong I; Trojanowski, John Q; Shaw, Leslie M

2012-10-01

A blood-based test that could be used as a screen for Alzheimer disease (AD) may enable early intervention and better access to treatment. To apply a multiplex immunoassay panel to identify plasma biomarkers of AD using plasma samples from the Alzheimer's Disease Neuroimaging Initiative cohort. Cohort study. The Biomarkers Consortium Alzheimer's Disease Plasma Proteomics Project. Plasma samples at baseline and at 1 year were analyzed from 396 (345 at 1 year) patients with mild cognitive impairment, 112 (97 at 1 year) patients with AD, and 58 (54 at 1 year) healthy control subjects. Multivariate and univariate statistical analyses were used to examine differences across diagnostic groups and relative to the apolipoprotein E (ApoE) genotype. Increased levels of eotaxin 3, pancreatic polypeptide, and N-terminal protein B-type brain natriuretic peptide were observed in patients, confirming similar changes reported in cerebrospinal fluid samples of patients with AD and MCI. Increases in tenascin C levels and decreases in IgM and ApoE levels were also observed. All participants with Apo ε3/ε4 or ε4/ε4 alleles showed a distinct biochemical profile characterized by low C-reactive protein and ApoE levels and by high cortisol, interleukin 13, apolipoprotein B, and gamma interferon levels. The use of plasma biomarkers improved specificity in differentiating patients with AD from controls, and ApoE plasma levels were lowest in patients whose mild cognitive impairment had progressed to dementia. Plasma biomarker results confirm cerebrospinal fluid studies reporting increased levels of pancreatic polypeptide and N-terminal protein B-type brain natriuretic peptide in patients with AD and mild cognitive impairment. Incorporation of plasma biomarkers yielded high sensitivity with improved specificity, supporting their usefulness as a screening tool. The ApoE genotype was associated with a unique biochemical profile irrespective of diagnosis, highlighting the importance of genotype on blood protein profiles.

Associations of aldosterone and renin concentrations with inflammation-the Study of Health in Pomerania and the German Conn's Registry.

PubMed

Grotevendt, A; Wallaschofski, H; Reincke, M; Adolf, C; Quinkler, M; Nauck, M; Hoffmann, W; Rettig, R; Hannemann, A

2017-08-01

Chronic inflammation is an age-independent and body mass index-independent contributor to the development of multi-morbidity. Alterations of the renin-angiotensin-aldosterone system are observed within the context of proinflammatory states. We assessed circulating aldosterone, renin, and inflammatory biomarker concentrations in healthy, normotensive subjects and patients with primary aldosteronism. We included 1177 normotensive individuals from the population-based Study of Health in Pomerania (first follow-up, Study of Health in Pomerania-1) and 103 primary aldosteronism patients from the German Conn's Registry. A 1:1 matching for sex, age, body mass index, smoking status, diabetes mellitus, and the estimated glomerular filtration rate was performed to determine whether primary aldosteronism patients exhibit higher inflammatory biomarker concentrations than normotensive controls. The associations of plasma aldosterone concentration or plasma renin concentration with circulating fibrinogen concentrations, white blood cell count, and high sensitive C-reactive protein concentrations in the normotensive sample were determined with multivariable linear and logistic regression analyses. 1:1 matched primary aldosteronism patients demonstrated significantly (p < 0.01) higher plasma aldosterone concentration (198 vs. 47 ng/l), lower plasma renin concentration (3.1 vs. 7.7 ng/l) and higher high sensitive C-reactive protein concentrations (1.5 vs. 1.0 mg/l) than normotensive controls. Within the normotensive cohort, plasma renin concentration but not plasma aldosterone concentration was positively associated with fibrinogen concentrations and white blood cell count. Further, a J-shaped association between plasma renin concentration and high sensitive C-reactive protein concentrations was detected. High plasma aldosterone concentration in a primary aldosteronism cohort and high plasma renin concentration in normotensive subjects are associated with increased concentrations of inflammatory biomarkers. This suggests a link between the renin-angiotensin-aldosterone system and inflammatory processes in patients with primary aldosteronism and even in normotensive subjects.

An Alternative to Annealing TiO2 Nanotubes for Morphology Preservation: Atmospheric Pressure Plasma Jet Treatment.

PubMed

Seo, Sang-Hee; Uhm, Soo-Hyuk; Kwon, Jae-Sung; Choi, Eun Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2015-03-01

Titanium oxide nanotube layer formed by plasma electrolytic oxidation (PEO) is known to be excellent in biomaterial applications. However, the annealing process which is commonly performed on the TiO2 nanotubes cause defects in the nanotubular structure. The purpose of this work was to apply a non-thermal atmospheric pressure plasma jet on diameter-controlled TiO2 nanotubes to mimic the effects of annealing while maintaining the tubular structure for use as biomaterial. Diameter-controlled nanotube samples fabricated by plasma electrolytic oxidation were dried and prepared under three different conditions: untreated, annealed at 450 °C for 1 h in air with a heating rate of 10 °C/min, and treated with an air-based non-thermal atmospheric pressure plasma jet for 5 minutes. The contact angle measurement was investigated to confirm the enhanced hydrophilicity of the TiO2 nanotubes. The chemical composition of the surface was studied using X-ray photoelectron spectroscopy, and the morphology of TiO2 nanotubes was examined by field emission scanning electron microscopy. For the viability of the cell, the attachment of the osteoblastic cell line MC3T3-E1 was determined using the water-soluble tetrazolium salt assay. We found that there are no morphological changes in the TiO2 nanotubular structure after the plasma treatment. Also, we investigated a change in the chemical composition and enhanced hydrophilicity which result in improved cell behavior. The results of this study indicated that the non-thermal atmospheric pressure plasma jet results in osteoblast functionality that is comparable to annealed samples while maintaining the tubular structure of the TiO2 nanotubes. Therefore, this study concluded that the use of a non-thermal atmospheric pressure plasma jet on nanotube surfaces may replace the annealing process following plasma electrolytic oxidation.

Chapter 8: Plasma operation and control

NASA Astrophysics Data System (ADS)

ITER Physics Expert Group on Disruptions, Control, Plasma, and MHD; ITER Physics Expert Group on Energetic Particles, Heating, Current and Drive; ITER Physics Expert Group on Diagnostics; ITER Physics Basis Editors

1999-12-01

Wall conditioning of fusion devices involves removal of desorbable hydrogen isotopes and impurities from interior device surfaces to permit reliable plasma operation. Techniques used in present devices include baking, metal film gettering, deposition of thin films of low-Z material, pulse discharge cleaning, glow discharge cleaning, radio frequency discharge cleaning, and in situ limiter and divertor pumping. Although wall conditioning techniques have become increasingly sophisticated, a reactor scale facility will involve significant new challenges, including the development of techniques applicable in the presence of a magnetic field and of methods for efficient removal of tritium incorporated into co-deposited layers on plasma facing components and their support structures. The current status of various approaches is reviewed, and the implications for reactor scale devices are summarized. Creation and magnetic control of shaped and vertically unstable elongated plasmas have been mastered in many present tokamaks. The physics of equilibrium control for reactor scale plasmas will rely on the same principles, but will face additional challenges, exemplified by the ITER/FDR design. The absolute positioning of outermost flux surface and divertor strike points will have to be precise and reliable in view of the high heat fluxes at the separatrix. Long pulses will require minimal control actions, to reduce accumulation of AC losses in superconducting PF and TF coils. To this end, more complex feedback controllers are envisaged, and the experimental validation of the plasma equilibrium response models on which such controllers are designed is encouraging. Present simulation codes provide an adequate platform on which equilibrium response techniques can be validated. Burning plasmas require kinetic control in addition to traditional magnetic shape and position control. Kinetic control refers to measures controlling density, rotation and temperature in the plasma core as well as in plasma periphery and divertor. The planned diagnostics (Chapter 7) serve as sensors for kinetic control, while gas and pellet fuelling, auxiliary power and angular momentum input, impurity injection, and non-inductive current drive constitute the control actuators. For example, in an ignited plasma, core density controls fusion power output. Kinetic control algorithms vary according to the plasma state, e.g. H- or L-mode. Generally, present facilities have demonstrated the kinetic control methods required for a reactor scale device. Plasma initiation - breakdown, burnthrough and initial current ramp - in reactor scale tokamaks will not involve physics differing from that found in present day devices. For ITER, the induced electric field in the chamber will be ~0.3V· m-1 - comparable to that required by breakdown theory but somewhat smaller than in present devices. Thus, a start-up 3MW electron cyclotron heating system will be employed to assure burnthrough. Simulations show that plasma current ramp up and termination in a reactor scale device can follow procedures developed to avoid disruption in present devices. In particular, simulations remain in the stable area of the li-q plane. For design purposes, the resistive V·s consumed during initiation is found, by experiments, to follow the Ejima expression, 0.45μ0 RIp. Advanced tokamak control has two distinct goals. First, control of density, auxiliary power, and inductive current ramping to attain reverse shear q profiles and internal transport barriers, which persist until dissipated by magnetic flux diffusion. Such internal transport barriers can lead to transient ignition. Second, combined use poloidal field shape control with non-inductive current drive and NBI angular momentum injection to create and control steady state, high bootstrap fraction, reverse shear discharges. Active n = 1 magnetic feedback and/or driven rotation will be required to suppress resistive wall modes for steady state plasmas that must operate in the wall stabilized regime for reactor levels of β >= 0.03.

A Real-Time Data Acquisition and Processing Framework Based on FlexRIO FPGA and ITER Fast Plant System Controller

NASA Astrophysics Data System (ADS)

Yang, C.; Zheng, W.; Zhang, M.; Yuan, T.; Zhuang, G.; Pan, Y.

2016-06-01

Measurement and control of the plasma in real-time are critical for advanced Tokamak operation. It requires high speed real-time data acquisition and processing. ITER has designed the Fast Plant System Controllers (FPSC) for these purposes. At J-TEXT Tokamak, a real-time data acquisition and processing framework has been designed and implemented using standard ITER FPSC technologies. The main hardware components of this framework are an Industrial Personal Computer (IPC) with a real-time system and FlexRIO devices based on FPGA. With FlexRIO devices, data can be processed by FPGA in real-time before they are passed to the CPU. The software elements are based on a real-time framework which runs under Red Hat Enterprise Linux MRG-R and uses Experimental Physics and Industrial Control System (EPICS) for monitoring and configuring. That makes the framework accord with ITER FPSC standard technology. With this framework, any kind of data acquisition and processing FlexRIO FPGA program can be configured with a FPSC. An application using the framework has been implemented for the polarimeter-interferometer diagnostic system on J-TEXT. The application is able to extract phase-shift information from the intermediate frequency signal produced by the polarimeter-interferometer diagnostic system and calculate plasma density profile in real-time. Different algorithms implementations on the FlexRIO FPGA are compared in the paper.

Bioengineering a Human Plasma-Based Epidermal Substitute With Efficient Grafting Capacity and High Content in Clonogenic Cells

PubMed Central

Alexaline, Maia M.; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T.; Doucet, Christelle; Fortunel, Nicolas O.

2015-01-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. Significance This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. PMID:25848122

Bioengineering a human plasma-based epidermal substitute with efficient grafting capacity and high content in clonogenic cells.

PubMed

Alexaline, Maia M; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T; Doucet, Christelle; Fortunel, Nicolas O; Lataillade, Jean-Jacques

2015-06-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. ©AlphaMed Press.

High Protein Intake Does Not Prevent Low Plasma Levels of Conditionally Essential Amino Acids in Very Preterm Infants Receiving Parenteral Nutrition.

PubMed

Morgan, Colin; Burgess, Laura

2017-03-01

We have shown that increasing protein intake using a standardized, concentrated, added macronutrients parenteral (SCAMP) nutrition regimen improves head growth in very preterm infants (VPIs) compared with a control parenteral nutrition (PN) regimen. VPIs are at risk of conditionally essential amino acid (CEAA) deficiencies because of current neonatal PN amino acid (AA) formulations. We hypothesized that the SCAMP regimen would prevent low plasma levels of CEAAs. To compare the plasma AA profiles at approximately day 9 of life in VPIs receiving SCAMP vs a control PN regimen. VPIs (<29 weeks' gestation) were randomized to receive SCAMP (30% more PN AA) or a control regimen. Data were collected to measure parenteral and enteral protein, energy, and individual AA intake and the first plasma AA profile. Plasma profiles of the 20 individual protogenic AA levels were measured using ion exchange chromatography. Plasma AA profiles were obtained at median (interquartile range [IQR]) age of 9 (8-10) days in both SCAMP (n = 59) and control (n = 67) groups after randomizing 150 VPIs. Median (IQR) plasma levels of individual essential AAs were higher than the reference population mean (RPM) in both groups, especially for threonine. SCAMP infants had higher plasma levels of essential AAs than did the controls. Median (IQR) plasma levels of glutamine, arginine, and cysteine (CEAAs) were lower than the RPM in both groups. Plasma AA levels in PN-dependent VPIs indicate there is an imbalance in essential and CEAA provision in neonatal PN AA formulations that is not improved by increasing protein intake.

Supersonic plasma jets in experiments for radiophysical testing of bodies flow

NASA Astrophysics Data System (ADS)

Balakirev, B. A.; Bityurin, V. A.; Bocharov, A. N.; Brovkin, V. G.; Vedenin, P. V.; Lashkov, V. A.; Mashek, I. Ch; Pashchina, A. S.; Petrovskiy, V. P.; Khoronzhuk, R. S.; Dobrovolskaya, A. S.

2018-01-01

The action of differently oriented magnetic fields on the parameters of bow shock created in the vicinity of aerodynamic bodies placed into the supersonic gas-plasma flows is studied. For these experiments two types of the high speed plasma jet sources are used—magneto-plasma compressor (MPC) and powerful pulse capillary type discharge. MPC allows to create the plasma jets with gas flow velocity of 10 ± 2 km/s, lifetime 30-50 μs, temperature Te ≈ 3 ± 0.5 eV, electron density about ne ˜ 1016cm-3 and temperature Te ≈ 3 ± 0.5 eV. The jet source based on powerful capillary discharge creates the flows with lifetime 1-20 ms, Mach numbers 3-8, plasma flow velocity 3-10 km/s, vibration and rotation temperatures 9000-14000 and 3800-6000 K respectively. The results of our first experiments show the possibility of using gas-plasma sources based on MPC and powerful capillary discharge for aerodynamic and radiophysical experiments. Comparatively small magnetic field B = 0.23-0.5 T, applied to the obtained bow shocks, essentially modify them. This can lead to a change in shape and an increase in the distance between the detached shock wave and the streamlined body surface if B is parallel to the jet velocity or to decrease this parameter if B is orthogonal to the oncoming flow. Probably, the first case can be useful for reducing the thermal load and aerodynamic drug of streamlined body and the second case can be used to control the radio-transparency of the plasma layer and solving the blackout problem.

Variable Specific Impulse Magnetoplasma Rocket Engine

NASA Technical Reports Server (NTRS)

Chang-Diaz, Franklin R. (Inventor)

2002-01-01

An engine is disclosed, including a controllable output plasma generator, a controllable heater for selectably raising a temperature of the plasma connected to an outlet of the plasma generator, and a nozzle connected to an outlet of the heater, through which heated plasma is discharged to provide thrust. In one embodiment, the source of plasma is a helicon generator. In one embodiment, the heater is an ion cyclotron resonator. In one embodiment, the nozzle is a radially diverging magnetic field disposed on a discharge side of the heater so that helically travelling particles in the beater exit the heater at high axial velocity. A particular embodiment includes control circuits for selectably directing a portion of radio frequency power from an RF generator to the helicon generator and to the cyclotron resonator so that the thrust output and the specific impulse of the engine can be selectively controlled. A method of propelling a vehicle is also disclosed. The method includes generating a plasma, heating said plasma, and discharging the heated plasma through a nozzle. In one embodiment, the nozzle is a diverging magnetic field. In this embodiment, the heating is performed by applying a radio frequency electro magnetic field to the plasma at the ion cyclotron frequency in an axially polarized DC magnetic field.

The Influence of Relative Humidity on Dielectric Barrier Discharge Plasma Flow Control Actuator Performance

NASA Astrophysics Data System (ADS)

Wicks, M.; Thomas, F. O.; Corke, T. C.; Patel, M.

2012-11-01

Dielectric barrier discharge (DBD) plasma actuators possess numerous advantages for flow control applications and have been the focus of several previous studies. Most work has been performed in relatively pristine laboratory settings. In actual flow control applications, however, it is essential to assess the impact of various environmental influences on actuator performance. As a first effort toward assessing a broad range of environmental effects on DBD actuator performance, the influence of relative humidity (RH) is considered. Actuator performance is quantified by force balance measurements of reactive thrust while RH is systematically varied via an ultrasonic humidifier. The DBD plasma actuator assembly, force balance, and ultrasonic humidifier are all contained inside a large, closed test chamber instrumented with RH and temperature sensors in order to accurately estimate the average RH at the actuator. Measurements of DBD actuator thrust as a function of RH for several different applied voltage regimes and dielectric materials and thicknesses are presented. Based on these results, several important design recommendations are made. This work was supported by Innovative Technology Applications Company (ITAC), LLC under a Small Business Innovation Research (SBIR) Phase II Contract No. N00014-11-C-0267 issued by the U.S. Department of the Navy.

Norepinephrine metabolism in neuron: dissociation between 3,4-dihydroxyphenylglycol and 3,4-dihydroxymandelic acid pathways.

PubMed

Dong, Wen-Xin; Ni, Xiang-Lian

2002-01-01

To investigate the pre-synaptic metabolism of norepinephrine (NE), judged by variations in plasma concentration of 3,4-dihydroxyphenylglycol (DHPG) and 3,4-dihydroxymandelic acid (DOMA). Pithed and electrically stimulated (2.5 Hz) rats were given intravenous infusion of exogenous NE (6 nmol . kg-1 . min-1). Plasma NE, DHPG, DOMA, and the activities of mono- amine oxidases (MAO) were measured with the radio-enzymatic assay. Exogenous NE induces an about 100-fold increase in plasma NE concentration while blood pressure remained within normal limits. A 12-fold increase in plasma DHPG and 1.2-fold increase for DOMA were observed. When NE transportation across the pre-synaptic membrane was inhibited by desipramine (2 mg/kg, iv), a great reduction in plasma DHPG concentration (about 25 % of control) was observed while DOMA remained unchanged. When MAO-A activity was inhibited to 25 % of control by clorgyline (2 mg/kg, iv) and MAO-B to 30 % by deprenyl, the plasma DHPG and DOMA concentrations were reduced to 15 % and 70 % of controls, and to 26 % and 76 % of controls, respectively. When clorgyline and deprenyl were combined, plasma DHPG was vanished (less than 2 % of control) while plasma DOMA remained in the same range (72 % of control). The metabolizing system of NE in pre-synapse, associating with the pre-synaptic reuptake plus oxidative deamination on the external membrane of mitochondria, is predominant for the reduction to DHPG.

Therapeutic Plasma Transfusion in Bleeding Patients: A Systematic Review.

PubMed

Levy, Jerrold H; Grottke, Oliver; Fries, Dietmar; Kozek-Langenecker, Sibylle

2017-04-01

Plasma products, including fresh frozen plasma, are administered extensively in a variety of settings from massive transfusion to vitamin K antagonist reversal. Despite the widespread use of plasma as a hemostatic agent in bleeding patients, its effect in comparison with other available choices of hemostatic therapies is unclear. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed Central, and databases of ongoing trials for randomized controlled trials that assessed the efficacy and/or safety of therapeutic plasma as an intervention to treat bleeding patients compared with other interventions or placebo. Of 1243 unique publications retrieved in our initial search, no randomized controlled trials were identified. Four nonrandomized studies described the effect of therapeutic plasma in bleeding patients; however, data gathered from these studies did not allow for comparison with other therapeutic interventions primarily as a result of the low number of patients and the use of different (or lack of) comparators. We identified two ongoing trials investigating the efficacy and safety of therapeutic plasma, respectively; however, no data have been released as yet. Although plasma is used extensively in the treatment of bleeding patients, evidence from randomized controlled trials comparing its effect with those of other therapeutic interventions is currently lacking.

Model Predictive Control of the Current Profile and the Internal Energy of DIII-D Plasmas

NASA Astrophysics Data System (ADS)

Lauret, M.; Wehner, W.; Schuster, E.

2015-11-01

For efficient and stable operation of tokamak plasmas it is important that the current density profile and the internal energy are jointly controlled by using the available heating and current-drive (H&CD) sources. The proposed approach is a version of nonlinear model predictive control in which the input set is restricted in size by the possible combinations of the H&CD on/off states. The controller uses real-time predictions over a receding-time horizon of both the current density profile (nonlinear partial differential equation) and the internal energy (nonlinear ordinary differential equation) evolutions. At every time instant the effect of every possible combination of H&CD sources on the current profile and internal energy is evaluated over the chosen time horizon. The combination that leads to the best result, which is assessed by a user-defined cost function, is then applied up until the next time instant. Simulations results based on a control-oriented transport code illustrate the effectiveness of the proposed control method. Supported by the US DOE under DE-FC02-04ER54698 & DE-SC0010661.

Deoxysphingoid bases as plasma markers in diabetes mellitus.

PubMed

Bertea, Mariana; Rütti, Markus F; Othman, Alaa; Marti-Jaun, Jaqueline; Hersberger, Martin; von Eckardstein, Arnold; Hornemann, Thorsten

2010-08-16

Sphingoid bases are formed from the precursors L-serine and palmitoyl-CoA-a reaction which is catalyzed by the serine-palmitoyltransferase (SPT). SPT metabolizes, besides palmitoyl-CoA also other acyl-CoAs but shows also variability towards the use of other amino acid substrates. The enzyme is also able to metabolize alanine, which results in the formation of an atypical deoxy-sphingoid base (DSB). This promiscuous activity is greatly increased in the case of the sensory neuropathy HSAN1, and pathologically elevated DSB levels have been identified as the cause of this disease. Clinically, HSAN1 shows a pronounced similarity to the diabetic sensory neuropathy (DSN), which is the most common chronic complication of diabetes mellitus. Since serine and alanine metabolism is functionally linked to carbohydrate metabolism by their precursors 3-phosphoglycerate and pyruvate, we were interested to see whether the levels of certain sphingoid base metabolites are altered in patients with diabetes. In a case-control study we compared plasma sphingoid base levels between healthy and diabetic individuals. DSB levels were higher in the diabetic group whereas C16 and C18 sphingoid bases were not significantly different. Plasma serine, but not alanine levels were lower in the diabetic group. A subsequent lipoprotein fractionation showed that the DSBs are primarily present in the LDL and VLDL fraction. Our results suggest that DSBs are a novel category of plasma biomarkers in diabetes which reflect functional impairments of carbohydrate metabolism. Furthermore, elevated DSB levels as we see them in diabetic patients might also contribute to the progression of the diabetic sensory neuropathy, the most frequent complication of diabetes.

ARC length control for plasma welding

NASA Technical Reports Server (NTRS)

Iceland, William F. (Inventor)

1988-01-01

A control system to be used with a plasma arc welding apparatus is disclosed. The plasma arc welding apparatus includes a plasma arc power supply, a contactor, and an electrode assembly for moving the electrode relative to a work piece. The electrode assembly is raised or lowered by a drive motor. The present apparatus includes a plasma arc adapter connected across the power supply to measure the voltage across the plasma arc. The plasma arc adapter forms a dc output signal input to a differential amplifier. A second input is defined by an adjustable resistor connected to a dc voltage supply to permit operator control. The differential amplifier forms an output difference signal provided to an adder circuit. The adder circuit then connects with a power amplifier which forms the driving signal for the motor. In addition, the motor connects to a tachometor which forms a feedback signal delivered to the adder to provide damping, therby avoiding servo loop overshoot.

THE DETERMINATION OF MERCURY SPECIES AND MULTIPLE METALS IN COAL COMBUSTION EMISSIONS USING IODINE-BASED IMPINGERS AND DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

EPA Science Inventory

Mercury (Hg) emissions from coal utilities are difficult to control. Hg eludes capture by most air pollution control devices (APCDs). To determine the gaseous Hg species in stack gases, U.S. EPA Method 5 type sampling is used. In this type of sampling a hole is drilled into th...

Numerical band structure calculations of plasma metamaterials

NASA Astrophysics Data System (ADS)

Pederson, Dylan; Kourtzanidis, Konstantinos; Raja, Laxminarayan

2015-09-01

Metamaterials (MM) are materials engineered to display negative macroscopic permittivity and permeability. These materials allow for designed control over electromagnetic energy flow, especially at frequencies where natural materials do not interact. Plasmas have recently found application in MM as a negative permittivity component. The permittivity of a plasma depends on its electron density, which can be controlled by an applied field. This means that plasmas can be used in MM to actively control the transmission or reflection of incident waves. This work focuses on a plasma MM geometry in which microplasmas are generated in perforations in a metal plate. We characterizethis material by its band structure, which describes its interaction with incident waves. The plasma-EM interactions are obtained by coupling Maxwell's equations to a simplified plasma momentum equation. A plasma density profile is prescribed, and its effect on the band structure is investigated. The band structure calculations are typically done for static structures, whereas our current density responds to the incident waves. The resulting band structures are compared with experimental results.

A field programmable gate array unit for the diagnosis and control of neoclassical tearing modes on MAST

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Gorman, T.; Gibson, K. J.; Snape, J. A.

2012-10-15

A real-time system has been developed to trigger both the MAST Thomson scattering (TS) system and the plasma control system on the phase and amplitude of neoclassical tearing modes (NTMs), extending the capabilities of the original system. This triggering system determines the phase and amplitude of a given NTM using magnetic coils at different toroidal locations. Real-time processing of the raw magnetic data occurs on a low cost field programmable gate array (FPGA) based unit which permits triggering of the TS lasers on specific amplitudes and phases of NTM evolution. The MAST plasma control system can receive a separate triggermore » from the FPGA unit that initiates a vertical shift of the MAST magnetic axis. Such shifts have fully removed m/n= 2/1 NTMs instabilities on a number of MAST discharges.« less

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henline, P.A.

1995-12-31

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DIII-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henline, P.A.

1995-10-01

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DRI-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Circular RNA hsa_circ_0000745 may serve as a diagnostic marker for gastric cancer.

PubMed

Huang, Mei; He, Yi-Ren; Liang, Li-Chuan; Huang, Qiang; Zhu, Zhi-Qiang

2017-09-14

To determine whether circular RNAs (circRNAs) are involved in pathological processes of gastric cancer (GC). Three circRNAs with differential expression in GC and colorectal cancer were randomly selected for validation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), using 20 pairs of gastric tissues and normal tissues. Based on the predicted circRNA-miRNA network, we then focused on hsa_circ_0000745, which was found to be down-regulated in 20 GC tissues compared with normal tissues. The hsa_circ_0000745 levels were further analyzed by qRT-PCR in 60 GC tissues and paired adjacent non-tumor tissues, as well as 60 plasma samples from GC patients and 60 plasma samples from healthy controls. The associations between the levels of hsa_circ_0000745 and the clinicopathological features of GC patients were statistically assessed. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of hsa_circ_0000745 in GC. Hsa_circ_0000745 was down-regulated in GC tissues vs non-tumorous tissues ( P < 0.001) and in plasma samples from patients with GC vs healthy controls ( P < 0.001). The expression level of hsa_circ_0000745 in GC tissues correlated with tumor differentiation, while the expression level in plasma correlated with tumor-node-metastasis stage. The area under the ROC curve (AUC) of hsa_circ_0000745 in plasma was 0.683, suggesting good diagnostic value. Plasma hsa_circ_0000745 level combined with carcinoembryogenic antigen (CEA) level increased the AUC to 0.775. Hsa_circ_0000745 plays an important role in GC and its expression level in plasma in combination with CEA level is a promising diagnostic marker for this malignancy.

Avoidance of tearing mode locking with electro-magnetic torque introduced by feedback-based mode rotation control in DIII-D and RFX-mod

DOE PAGES

Okabayashi, M.; Zanca, P.; Strait, E. J.; ...

2016-11-25

Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. We have demonstrated a promising scheme to avoid mode locking by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque is delivered to the modes by a toroidal phase shift between the externally applied field and the excited TM fields, compensating for the mode momentum loss through the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance ismore » provided by a feedback scheme. We have explored this approach in two widely different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high β N in a non-circular divertor tokamak. We define β N as β N = β/(I p /aB t) (%Tm/MA), where β, I p, a, B t are the total stored plasma pressure normalized by the magnetic pressure, plasma current, plasma minor radius and toroidal magnetic field at the plasma center, respectively. The RFX-mod plasma was ohmically-heated with ultra-low safety factor in a circular limiter discharge with active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as the International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. Finally, the internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited for this purpose.« less

The Impact of Plasma Treatment of Cercon® Zirconia Ceramics on Adhesion to Resin Composite Cements and Surface Properties.

PubMed

Tabari, Kasra; Hosseinpour, Sepanta; Mohammad-Rahimi, Hossein

2017-01-01

Introduction: In recent years, the use of ceramic base zirconia is considered in dentistry for all ceramic restorations because of its chemical stability, biocompatibility, and good compressive as well as flexural strength. However, due to its chemical stability, there is a challenge with dental bonding. Several studies have been done to improve zirconia bonding but they are not reliable. The purpose of this research is to study the effect of plasma treatment on bonding strength of zirconia. Methods: In this in vitro study, 180 zirconia discs' (thickness was 0.85-0.9 mm) surfaces were processed with plasma of oxygen, argon, air and oxygen-argon combination with 90-10 and 80-20 ratio (n=30 for each group) after being polished by sandblast. Surface modifications were assessed by measuring the contact angle, surface roughness, and topographical evaluations. Cylindrical Panavia f2 resin-cement and Diafill were used for microshear strength bond measurements. The data analysis was performed by SPSS 20.0 software and one-way analysis of variance (ANOVA) and Tukey test as the post hoc. Results: Plasma treatment in all groups significantly reduces contact angle compare with control ( P =0.001). Topographic evaluations revealed coarseness promotion occurred in all plasma treated groups which was significant when compared to control ( P <0.05), except argon plasma treated group that significantly decreased surface roughness ( P <0.05). In all treated groups, microshear bond strength increased, except oxygen treated plasma group which decreased this strength. Air and argon-oxygen combination (both groups) significantly increased microshear bond strength ( P <0.05). Conclusion: According to this research, plasmatic processing with dielectric barrier method in atmospheric pressure can increase zirconia bonding strength.

Fasting Plasma Glucose, Self-Appraised Diet Quality and Depressive Symptoms: A US-Representative Cross-Sectional Study.

PubMed

Hoare, Erin; Dash, Sarah R; Varsamis, Pia; Jennings, Garry L; Kingwell, Bronwyn A

2017-12-07

Depression and type 2 diabetes (T2D) contribute significantly to global burden of disease and often co-occur. Underpinning type 2 diabetes is poor glycaemic control and glucose is also an obligatory substrate for brain metabolism, with potential implications for cognition, motivation and mood. This research aimed to examine the relationships between fasting plasma glucose and depressive symptoms in a large, population representative sample of US adults, controlling for other demographic and lifestyle behavioural risk factors. Using the 2013-2014 National Health and Nutrition Examination Survey (NHANES) data, this study first investigated the relationship between fasting plasma glucose and mental disorders at a population-level, accounting for demographic, health behavioural and weight-related factors known to co-occur with both type 2 diabetes and mental disorders. Depressive symptoms were derived from the 9-item Patient Health Questionnaire. Fasting plasma glucose was obtained through medical examination and demographic (age, household income, sex) and health characteristics (perceived diet quality, daily time sedentary) were self-reported. Body mass index was calculated from objectively measured height and weight. In the univariate model, higher fasting plasma glucose was associated with greater depressive symptoms among females ( b = 0.24, 95% CI = 0.05, 0.43, p < 0.05), but not males. In the final fully adjusted model, the relationship between fasting plasma glucose and depressive symptoms was non-significant for both males and females. Of all independent variables, self-appraised diet quality was strongly and significantly associated with depressive symptoms and this remained significant when individuals with diabetes were excluded. Although diet quality was self-reported based on individuals' perceptions, these findings are consistent with a role for poor diet in the relationship between fasting plasma glucose and depressive symptoms.

Avoidance of tearing mode locking with electro-magnetic torque introduced by feedback-based mode rotation control in DIII-D and RFX-mod

NASA Astrophysics Data System (ADS)

Okabayashi, M.; Zanca, P.; Strait, E. J.; Garofalo, A. M.; Hanson, J. M.; In, Y.; La Haye, R. J.; Marrelli, L.; Martin, P.; Paccagnella, R.; Paz-Soldan, C.; Piovesan, P.; Piron, C.; Piron, L.; Shiraki, D.; Volpe, F. A.; DIII-D, The; RFX-mod Teams

2017-01-01

Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a promising scheme to avoid mode locking by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque is delivered to the modes by a toroidal phase shift between the externally applied field and the excited TM fields, compensating for the mode momentum loss through the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two widely different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high β N in a non-circular divertor tokamak. Here β N is defined as β N  =  β/(I p /aB t) (%Tm/MA), where β, I p, a, B t are the total stored plasma pressure normalized by the magnetic pressure, plasma current, plasma minor radius and toroidal magnetic field at the plasma center, respectively. The RFX-mod plasma was ohmically-heated with ultra-low safety factor in a circular limiter discharge with active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as the International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited for this purpose.

An in situ accelerator-based diagnostic for plasma-material interactions science on magnetic fusion devices.

PubMed

Hartwig, Zachary S; Barnard, Harold S; Lanza, Richard C; Sorbom, Brandon N; Stahle, Peter W; Whyte, Dennis G

2013-12-01

This paper presents a novel particle accelerator-based diagnostic that nondestructively measures the evolution of material surface compositions inside magnetic fusion devices. The diagnostic's purpose is to contribute to an integrated understanding of plasma-material interactions in magnetic fusion, which is severely hindered by a dearth of in situ material surface diagnosis. The diagnostic aims to remotely generate isotopic concentration maps on a plasma shot-to-shot timescale that cover a large fraction of the plasma-facing surface inside of a magnetic fusion device without the need for vacuum breaks or physical access to the material surfaces. Our instrument uses a compact (~1 m), high-current (~1 milliamp) radio-frequency quadrupole accelerator to inject 0.9 MeV deuterons into the Alcator C-Mod tokamak at MIT. We control the tokamak magnetic fields--in between plasma shots--to steer the deuterons to material surfaces where the deuterons cause high-Q nuclear reactions with low-Z isotopes ~5 μm into the material. The induced neutrons and gamma rays are measured with scintillation detectors; energy spectra analysis provides quantitative reconstruction of surface compositions. An overview of the diagnostic technique, known as accelerator-based in situ materials surveillance (AIMS), and the first AIMS diagnostic on the Alcator C-Mod tokamak is given. Experimental validation is shown to demonstrate that an optimized deuteron beam is injected into the tokamak, that low-Z isotopes such as deuterium and boron can be quantified on the material surfaces, and that magnetic steering provides access to different measurement locations. The first AIMS analysis, which measures the relative change in deuterium at a single surface location at the end of the Alcator C-Mod FY2012 plasma campaign, is also presented.

Non-enzymatic antioxidant capacity (NEAC) estimated by two different dietary assessment methods and its relationship with NEAC plasma levels.

PubMed

Carrión-García, Cayetano Javier; Guerra-Hernández, Eduardo J; García-Villanova, Belén; Molina-Montes, Esther

2017-06-01

We aimed to quantify and compare dietary non-enzymatic antioxidant capacity (NEAC), estimated using two dietary assessment methods, and to explore its relationship with plasma NEAC. Fifty healthy subjects volunteer to participate in this study. Two dietary assessment methods [a food frequency questionnaire (FFQ) and a 24-hour recall (24-HR)] were used to collect dietary information. Dietary NEAC, including oxygen radical absorbance capacity (ORAC), total polyphenols, ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity, was estimated using several data sources of NEAC content in food. NEAC status was measured in fasting blood samples using the same assays. We performed nonparametric Spearman's correlation analysis between pairs of dietary NEAC (FFQ and 24-HR) and diet-plasma NEAC, with and without the contribution of coffee's NEAC. Partial correlation analysis was used to estimate correlations regardless of variables potentially influencing these relationships. FFQ-based NEAC and 24-HR-based NEAC were moderately correlated, with correlation coefficients ranging from 0.54 to 0.71, after controlling for energy intake, age and sex. Statistically significant positive correlations were found for dietary FRAP, either derived from the FFQ or the 24-HR, with plasma FRAP (r ~ 0.30). This weak, albeit statistically significant, correlation for FRAP was mostly present in the fruits and vegetables food groups. Plasma ORAC without proteins and 24-HR-based total ORAC were also positively correlated (r = 0.35). The relationship between dietary NEAC and plasma FRAP and ORAC suggests the dietary NEAC may reflect antioxidant status despite its weak in vivo potential, supporting further its use in oxidative stress-related disease epidemiology.

Novel aspects of plasma control in ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humphreys, D.; Jackson, G.; Walker, M.

2015-02-15

ITER plasma control design solutions and performance requirements are strongly driven by its nuclear mission, aggressive commissioning constraints, and limited number of operational discharges. In addition, high plasma energy content, heat fluxes, neutron fluxes, and very long pulse operation place novel demands on control performance in many areas ranging from plasma boundary and divertor regulation to plasma kinetics and stability control. Both commissioning and experimental operations schedules provide limited time for tuning of control algorithms relative to operating devices. Although many aspects of the control solutions required by ITER have been well-demonstrated in present devices and even designed satisfactorily formore » ITER application, many elements unique to ITER including various crucial integration issues are presently under development. We describe selected novel aspects of plasma control in ITER, identifying unique parts of the control problem and highlighting some key areas of research remaining. Novel control areas described include control physics understanding (e.g., current profile regulation, tearing mode (TM) suppression), control mathematics (e.g., algorithmic and simulation approaches to high confidence robust performance), and integration solutions (e.g., methods for management of highly subscribed control resources). We identify unique aspects of the ITER TM suppression scheme, which will pulse gyrotrons to drive current within a magnetic island, and turn the drive off following suppression in order to minimize use of auxiliary power and maximize fusion gain. The potential role of active current profile control and approaches to design in ITER are discussed. Issues and approaches to fault handling algorithms are described, along with novel aspects of actuator sharing in ITER.« less

Novel aspects of plasma control in ITER

DOE PAGES

Humphreys, David; Ambrosino, G.; de Vries, Peter; ...

2015-02-12

ITER plasma control design solutions and performance requirements are strongly driven by its nuclear mission, aggressive commissioning constraints, and limited number of operational discharges. In addition, high plasma energy content, heat fluxes, neutron fluxes, and very long pulse operation place novel demands on control performance in many areas ranging from plasma boundary and divertor regulation to plasma kinetics and stability control. Both commissioning and experimental operations schedules provide limited time for tuning of control algorithms relative to operating devices. Although many aspects of the control solutions required by ITER have been well-demonstrated in present devices and even designed satisfactorily formore » ITER application, many elements unique to ITER including various crucial integration issues are presently under development. We describe selected novel aspects of plasma control in ITER, identifying unique parts of the control problem and highlighting some key areas of research remaining. Novel control areas described include control physics understanding (e.g. current profile regulation, tearing mode suppression (TM)), control mathematics (e.g. algorithmic and simulation approaches to high confidence robust performance), and integration solutions (e.g. methods for management of highly-subscribed control resources). We identify unique aspects of the ITER TM suppression scheme, which will pulse gyrotrons to drive current within a magnetic island, and turn the drive off following suppression in order to minimize use of auxiliary power and maximize fusion gain. The potential role of active current profile control and approaches to design in ITER are discussed. Finally, issues and approaches to fault handling algorithms are described, along with novel aspects of actuator sharing in ITER.« less

MHD Instabilities and Toroidal Field Effects on Plasma Column Behavior in Tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khorshid, Pejman; Plasma Physics Research Center, Islamic Azad University, 14665-678, Tehran; Wang, L.

2006-12-04

In the edge plasma of the CT-6B and IRAN-T1 tokamaks the shape of plasma column based on MHD behavior has been studied. The bulk of plasma behavior during plasma column rotation as non-rigid body plasma has been investigated. We found that mode number and rotation frequency of plasma column are different in angle position, so that the mode number detected from Mirnov coils array located in poloidal angle on the inner side of chamber is more than outer side which it can be because of toroidal magnetic field effects. The results of IR-T1 and CT-6B tokamaks compared with each other,more » so that in the CT-6B because of its coils number must be less, but because of its Iron core the effect of toroidal magnetic field became more effective with respect to IR-T1. In addition, it is shown that the plasma column behaves as non-Rigid body plasma so that the poloidal rotation velocity variation in CT-6B is more than IR-T1. A relative correction for island rotation frequency has been suggested in connection with IRAN-T1 and CT-6B tokamak results, which can be considered for optical measurement purposes and also for future advanced tokamak control design.« less

Approaching the investigation of plasma turbulence through a rigorous verification and validation procedure: A practical example

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricci, P., E-mail: paolo.ricci@epfl.ch; Riva, F.; Theiler, C.

In the present work, a Verification and Validation procedure is presented and applied showing, through a practical example, how it can contribute to advancing our physics understanding of plasma turbulence. Bridging the gap between plasma physics and other scientific domains, in particular, the computational fluid dynamics community, a rigorous methodology for the verification of a plasma simulation code is presented, based on the method of manufactured solutions. This methodology assesses that the model equations are correctly solved, within the order of accuracy of the numerical scheme. The technique to carry out a solution verification is described to provide a rigorousmore » estimate of the uncertainty affecting the numerical results. A methodology for plasma turbulence code validation is also discussed, focusing on quantitative assessment of the agreement between experiments and simulations. The Verification and Validation methodology is then applied to the study of plasma turbulence in the basic plasma physics experiment TORPEX [Fasoli et al., Phys. Plasmas 13, 055902 (2006)], considering both two-dimensional and three-dimensional simulations carried out with the GBS code [Ricci et al., Plasma Phys. Controlled Fusion 54, 124047 (2012)]. The validation procedure allows progress in the understanding of the turbulent dynamics in TORPEX, by pinpointing the presence of a turbulent regime transition, due to the competition between the resistive and ideal interchange instabilities.« less

Population-specific plasma proteomes of marine and freshwater three-spined sticklebacks (Gasterosteus aculeatus).

PubMed

Kültz, Dietmar; Li, Johnathon; Zhang, Xuezhen; Villarreal, Fernando; Pham, Tuan; Paguio, Darlene

2015-12-01

Molecular phenotypes that distinguish resident marine (Bodega Harbor) from landlocked freshwater (FW, Lake Solano) three-spined sticklebacks were revealed by label-free quantitative proteomics. Secreted plasma proteins involved in lipid transport, blood coagulation, proteolysis, plasminogen-activating cascades, extracellular stimulus responses, and immunity are most abundant in this species. Globulins and albumins are much less abundant than in mammalian plasma. Unbiased quantitative proteome profiling identified 45 highly population-specific plasma proteins. Population-specific abundance differences were validated by targeted proteomics based on data-independent acquisition. Gene ontology enrichment analyses and known functions of population-specific plasma proteins indicate enrichment of processes controlling cell adhesion, tissue remodeling, proteolytic processing, and defense signaling in marine sticklebacks. Moreover, fetuin B and leukocyte cell derived chemotaxin 2 are much more abundant in marine fish. These proteins promote bone morphogenesis and likely contribute to population-specific body armor differences. Plasma proteins enriched in FW fish promote translation, heme biosynthesis, and lipid transport, suggesting a greater presence of plasma microparticles. Many prominent population-specific plasma proteins (e.g. apoptosis-associated speck-like protein containing a CARD) lack any homolog of known function or adequate functional characterization. Their functional characterization and the identification of population-specific environmental contexts and selective pressures that cause plasma proteome diversification are future directions emerging from this study. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasma Fibrinogen in Patients With Bell Palsy.

PubMed

Zhao, Hua; Zhang, Xin; Tang, Yinda; Li, Shiting

2016-10-01

To determine the plasma fibrinogen level in patients with Bell palsy and explore the significances of it in Bell palsy. One hundred five consecutive patients with facial paralysis were divided into 3 groups: group I (Bell palsy), group II (temporal bone fractures), and group III (facial nerve schwannoma). In addition, 22 volunteers were defined as control group. Two milliliters fasting venous blood from elbow was collected, and was evaluated by CA-7000 Full-Automatic Coagulation Analyzer. The plasma fibrinogen concentration was significantly higher in the group of patients with Bell palsy (HB IV-VI) than that in the control group (P <0.05). There was no significant difference between group II and control group (P >0.05); similarly, there was also no marked difference between group III and control group (P >0.05). In group I, the plasma fibrinogen levels became higher with the HB grading increase. The plasma fibrinogen level of HB-VI was highest. Plasma fibrinogen has an important clinical meaning in Bell palsy, which should be used as routine examination items. Defibrinogen in treatment for patients with high plasma fibrinogen content also should be suggested.

Validation of Reported Whole-Grain Intake from a Web-Based Dietary Record against Plasma Alkylresorcinol Concentrations in 8- to 11-Year-Olds Participating in a Randomized Controlled Trial.

PubMed

Biltoft-Jensen, Anja; Damsgaard, Camilla T; Andersen, Elisabeth W; Ygil, Karin H; Andersen, Rikke; Ege, Majken; Christensen, Tue; Thorsen, Anne-Vibeke; Tetens, Inge; Wu, Huaxing; Landberg, Rikard

2016-02-01

Whole-grain (WG) intake is important for human health, but accurate intake estimation is challenging. Use of a biomarker for WG intake provides a possible way to validate dietary assessment methods. Our aim was to validate WG intake from 2 diets reported by children, using plasma alkylresorcinol (AR) concentrations, and to investigate the 3-mo reproducibility of AR concentrations and reported WG intake. AR concentrations were analyzed in fasting blood plasma samples, and WG intake was estimated in a 7-d web-based diary by 750 participants aged 8-11 y in a 2 school meal × 3 mo crossover trial. Reported WG intake and plasma AR concentrations were compared when children ate their usual bread-based lunch (UBL) and when served a hot lunch meal (HLM). Correlations and cross-classification were used to rank subjects according to intake. The intraclass correlation coefficients (ICCs) between subjects' measurements at baseline and after the UBL were used to assess reproducibility. Correlations between reported WG wheat + rye intake and plasma AR were 0.40 and 0.37 (P < 0.001) for the UBL and the HLM diets, and 78% and 77% were classified in the same or adjacent quartiles for the UBL and HLM diets, respectively. The ICC over 3 mo was 0.47 (95% CI: 0.38, 0.55) for plasma total ARs and 0.64 (95% CI: 0.58, 0.70) for reported WG intake. Correlations were higher when using the AR C17:0 homolog as a biomarker, reflecting rye intake instead of plasma total ARs [UBL: r = 0.47; HLM: r = 0.43, P < 0.001; ICC = 0.51 (95% CI: 0.43, 0.59)]. Self-reported WG wheat + rye intake among children showed moderate correlations with plasma AR concentrations. Substantial intraindividual variation was found in WG intake and plasma AR concentrations. The AR homolog C17:0 may be used as a biomarker for WG intake when the WG intake primarily comes from rye as in the present study. This trial was registered at clinicaltrials.gov as NCT01457794. © 2016 American Society for Nutrition.

Diagnostics for real-time plasma control in PBX-M

NASA Astrophysics Data System (ADS)

Kaita, R.; Batha, S.; Bell, R. E.; Bernabei, S.; Hatcher, R.; Kozub, T.; Kugel, H.; Levinton, F.; Okabayashi, M.; Sesnic, S.; von Goeler, S.; Zolfaghari, A.; PBX-M Group

1995-01-01

An important issue for future tokamaks is real-time plasma control for the avoidance of magnetohydrodynamic instabilities and other applications that require detailed plasma profile and fluctuation data. Although measurements from diagnostics providing this information require significantly more processing than magnetic flux data, recent advancements could make them practical for adjusting operational settings for plasma heating and current drive systems as well as field coil currents. On the Princeton Beta Experiment-Modification (PBX-M), the lower hybrid current drive phasing can be varied during a plasma shot using digitally programmable ferrite phase shifters, and neural beam functions can be fully computer controlled. PBX-M diagnostics that may be used for control purposes include motional Stark-effect polarimetry for magnetic field pitch angle profiles, soft x-ray arrays for plasma position control and the separation of βp from li, hard x-ray detectors for energetic electron distributions, a multichannel electron cyclotron emission radiometer for ballooning mode identification, and passive plate eddy current monitors for kink stabilization. We will describe the present status of these systems on PBX-M, and discuss their suitability for feedback applications.

Automated plasma control with optical emission spectroscopy

NASA Astrophysics Data System (ADS)

Ward, P. P.

Plasma etching and desmear processes for printed wiring board (PWB) manufacture are difficult to predict and control. Non-uniformity of most plasma processes and sensitivity to environmental changes make it difficult to maintain process stability from day to day. To assure plasma process performance, weight loss coupons or post-plasma destructive testing must be used. These techniques are not real-time methods however, and do not allow for immediate diagnosis and process correction. These tests often require scrapping some fraction of a batch to insure the integrity of the rest. Since these tests verify a successful cycle with post-plasma diagnostics, poor test results often determine that a batch is substandard and the resulting parts unusable. These tests are a costly part of the overall fabrication cost. A more efficient method of testing would allow for constant monitoring of plasma conditions and process control. Process anomalies should be detected and corrected before the parts being treated are damaged. Real time monitoring would allow for instantaneous corrections. Multiple site monitoring would allow for process mapping within one system or simultaneous monitoring of multiple systems. Optical emission spectroscopy conducted external to the plasma apparatus would allow for this sort of multifunctional analysis without perturbing the glow discharge. In this paper, optical emission spectroscopy for non-intrusive, in situ process control will be explored along with applications of this technique to for process control, failure analysis and endpoint determination in PWB manufacture.

Hardwired Control Changes For NSTX DC Power Feeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramakrishnan, S.

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The original TFTR Hardwired Control System (HCS) with electromechanical relays was used for NSTX DC Power loop control and protection during NSTX operations. As part of the NSTX Upgrade, the HCS is being changed to a PLC-based system with the same control logic. This paper gives a description ofmore » the changeover to the new PLC-based system __________________________________________________« less

Association of plasma sRAGE, but not esRAGE with lung function impairment in COPD.

PubMed

Gopal, Poornima; Reynaert, Niki L; Scheijen, Jean L J M; Schalkwijk, Casper G; Franssen, Frits M E; Wouters, Emiel F M; Rutten, Erica P A

2014-02-25

Plasma soluble Receptor for Advanced Glycation End Product (sRAGE) is considered as a biomarker in COPD. The contribution of endogenous sRAGE (esRAGE) to the pool of plasma sRAGE and the implication of both markers in COPD pathogenesis is however not clear yet. The aim of the current study was therefore to measure plasma levels of esRAGE comparative to total sRAGE in patients with COPD and a control group. Further, we established the relations of esRAGE and total sRAGE with disease specific characteristics such as lung function and DLCO, and with different circulating AGEs. Plasma levels of esRAGE and sRAGE were measured in an 88 patients with COPD and in 55 healthy controls. FEV1 (%predicted) and FEV1/VC (%) were measured in both groups; DLCO (%predicted) was measured in patients only. In this study population we previously reported that the AGE Nϵ-(carboxymethyl) lysine (CML) was decreased, Nϵ-(carboxyethyl) lysine (CEL) increased and pentosidine was not different in plasma of COPD patients compared to controls. Plasma esRAGE (COPD: 533.9 ± 412.4, CONTROLS: 848.7 ± 690.3 pg/ml; p = 0.000) was decreased in COPD compared to controls. No significant correlations were observed between plasma esRAGE levels and lung function parameters or plasma AGEs. A positive correlation was present between esRAGE and total sRAGE levels in the circulation. Confirming previous findings, total sRAGE (COPD: 512.6 ± 403.8, CONTROLS: 1834 ± 804.2 pg/ml; p < 0.001) was lower in patients compared to controls and was positively correlated FEV1 (r = 0.235, p = 0.032), FEV1/VC (r = 0.218, p = 0.047), and DLCO (r = 0.308, p = 0.006). sRAGE furthermore did show a significant positive association with CML (r = 0.321, p = 0.003). Although plasma esRAGE is decreased in COPD patients compared to controls, only total sRAGE showed a significant and independent association with FEV1, FEV1/VC and DLCO, indicating that total sRAGE but not esRAGE may serve as marker of COPD disease state and severity.

SPINS-IND: Pellet injector for fuelling of magnetically confined fusion systems.

PubMed

Gangradey, R; Mishra, J; Mukherjee, S; Panchal, P; Nayak, P; Agarwal, J; Saxena, Y C

2017-06-01

Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law. The pellet shape is cylindrical of dimension (1.6 mm ℓ × 1.8 mm φ). For pellet ejection and acceleration, a fast opening valve of short opening duration is installed at the breech of the barrel. A three-stage differential pumping system is used to restrict the flow of the propellant gas into the plasma vacuum vessel. Diagnostic systems such as light gate and fast imaging camera (240 000 frames/s) are employed to measure the pellet speed and size, respectively. A trigger circuit and a programmable logic controller based integrated control system developed on LabVIEW enables to control the pellet injector remotely. Using helium as a propellant gas, the pellet speed is varied in the range 650 m/s-800 m/s. The reliability of pellet formation and ejection is found to be more than 95%. This paper describes the details of SPINS-IND and its test results.

SPINS-IND: Pellet injector for fuelling of magnetically confined fusion systems

NASA Astrophysics Data System (ADS)

Gangradey, R.; Mishra, J.; Mukherjee, S.; Panchal, P.; Nayak, P.; Agarwal, J.; Saxena, Y. C.

2017-06-01

Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law. The pellet shape is cylindrical of dimension (1.6 mm ℓ × 1.8 mm φ). For pellet ejection and acceleration, a fast opening valve of short opening duration is installed at the breech of the barrel. A three-stage differential pumping system is used to restrict the flow of the propellant gas into the plasma vacuum vessel. Diagnostic systems such as light gate and fast imaging camera (240 000 frames/s) are employed to measure the pellet speed and size, respectively. A trigger circuit and a programmable logic controller based integrated control system developed on LabVIEW enables to control the pellet injector remotely. Using helium as a propellant gas, the pellet speed is varied in the range 650 m/s-800 m/s. The reliability of pellet formation and ejection is found to be more than 95%. This paper describes the details of SPINS-IND and its test results.

Effects of glutamine on gastrointestinal motor activity in patients following gastric surgery.

PubMed

Mochiki, Erito; Ohno, Tetsuro; Yanai, Mitsuhiro; Toyomasu, Yoshitaka; Andoh, Hiroyuki; Kuwano, Hiroyuki

2011-04-01

Postoperative ileus (POI) is one of the most common complications of gastrointestinal surgery. The present study was performed to evaluate the effects of glutamine administration on POI after gastric surgery in humans. The subjects were 31 patients who underwent partial distal gastrectomy for gastric cancer and who were randomly assigned to one of two groups based on postoperative treatment: the glutamine group (3 g/day) and the control group. Manometric recording was done 12 days after surgery, and plasma glutamine concentrations were measured preoperatively and on postoperative day 12. Motor activities of the duodenum in the glutamine group were significantly greater than those of the control group in the interdigestive state. The incidence of phase III motor activity (interdigestive migrating motor contractions) in the glutamine group was significantly higher than that in the control group (60 versus 19%). The glutamine group showed a significantly smaller decrease of plasma glutamine levels compared with the control group. Glutamine could act as a motility-recovery agent after gastrectomy in humans.

Plasma proteomic analysis reveals altered protein abundances in cardiovascular disease.

PubMed

Lygirou, Vasiliki; Latosinska, Agnieszka; Makridakis, Manousos; Mullen, William; Delles, Christian; Schanstra, Joost P; Zoidakis, Jerome; Pieske, Burkert; Mischak, Harald; Vlahou, Antonia

2018-04-17

Cardiovascular disease (CVD) describes the pathological conditions of the heart and blood vessels. Despite the large number of studies on CVD and its etiology, its key modulators remain largely unknown. To this end, we performed a comprehensive proteomic analysis of blood plasma, with the scope to identify disease-associated changes after placing them in the context of existing knowledge, and generate a well characterized dataset for further use in CVD multi-omics integrative analysis. LC-MS/MS was employed to analyze plasma from 32 subjects (19 cases of various CVD phenotypes and 13 controls) in two steps: discovery (13 cases and 8 controls) and test (6 cases and 5 controls) set analysis. Following label-free quantification, the detected proteins were correlated to existing plasma proteomics datasets (plasma proteome database; PPD) and functionally annotated (Cytoscape, Ingenuity Pathway Analysis). Differential expression was defined based on identification confidence (≥ 2 peptides per protein), statistical significance (Mann-Whitney p value ≤ 0.05) and a minimum of twofold change. Peptides detected in at least 50% of samples per group were considered, resulting in a total of 3796 identified proteins (838 proteins based on ≥ 2 peptides). Pathway annotation confirmed the functional relevance of the findings (representation of complement cascade, fibrin clot formation, platelet degranulation, etc.). Correlation of the relative abundance of the proteins identified in the discovery set with their reported concentrations in the PPD was significant, confirming the validity of the quantification method. The discovery set analysis revealed 100 differentially expressed proteins between cases and controls, 39 of which were verified (≥ twofold change) in the test set. These included proteins already studied in the context of CVD (such as apolipoprotein B, alpha-2-macroglobulin), as well as novel findings (such as low density lipoprotein receptor related protein 2 [LRP2], protein SZT2) for which a mechanism of action is suggested. This proteomic study provides a comprehensive dataset to be used for integrative and functional studies in the field. The observed protein changes reflect known CVD-related processes (e.g. lipid uptake, inflammation) but also novel hypotheses for further investigation including a potential pleiotropic role of LPR2 but also links of SZT2 to CVD.

Identification of vinculin as a potential plasma marker for age-related macular degeneration.

PubMed

Kim, Hye-Jung; Woo, Se Joon; Suh, Eui Jin; Ahn, Jeeyun; Park, Ji Hyun; Hong, Hye Kyoung; Lee, Ji Eun; Ahn, Seong Joon; Hwang, Duck Jin; Kim, Ki Woong; Park, Kyu Hyung; Lee, Cheolju

2014-10-08

To identify plasma protein biomarkers for age-related macular degeneration (AMD) using a large-scale quantitative proteomic discovery procedure. Plasma proteomes from 20 exudative AMD patients and 20 healthy control patients were comparatively profiled by four-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS). Proteins existing at statistically different levels were validated by enzyme-linked immunosorbent assay (ELISA) and Western blotting in 233 case-controlled samples. Newly discovered plasma biomarkers were further confirmed using in vivo and in vitro experiments. Out of 320 proteins identified, vinculin, protein S100A9, triosephosphate isomerase, protein S100A8, protein Z-dependent protease inhibitor, C-X-C motif chemokine 7, and tenascin X showed significantly differential expression in AMD patient plasma compared to control plasma. Among these, the area under the curve (AUC) for vinculin was 0.871 for discriminating between exudative AMD and controls (n = 201) and 0.879 for discriminating between AMD and controls (n = 233). A proteogenomic combination model using vinculin and two known risk genotypes in ARMS2 and CFH genes additionally provided excellent discrimination of AMD from controls (AUC = 0.916). The plasma level of vinculin was not associated with any confounding clinical variables, such as age, smoking, and other comorbidities. Additionally, vinculin was strongly expressed in retinal pigment epithelial cells of human eyes, and its expression was elevated when exposed to oxidative stress in vitro. Vinculin was identified as a potential plasma biomarker for AMD. The early detection of AMD using novel plasma biomarkers with genetic modeling may enable timely treatment and vision preservation in the elderly. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Nonlinear dynamics of mini-satellite respinup by weak internal controllable torques

NASA Astrophysics Data System (ADS)

Somov, Yevgeny

2014-12-01

Contemporary space engineering advanced new problem before theoretical mechanics and motion control theory: a spacecraft directed respinup by the weak restricted control internal forces. The paper presents some results on this problem, which is very actual for energy supply of information mini-satellites (for communication, geodesy, radio- and opto-electronic observation of the Earth et al.) with electro-reaction plasma thrusters and gyro moment cluster based on the reaction wheels or the control moment gyros. The solution achieved is based on the methods for synthesis of nonlinear robust control and on rigorous analytical proof for the required spacecraft rotation stability by Lyapunov function method. These results were verified by a computer simulation of strongly nonlinear oscillatory processes at respinuping of a flexible spacecraft.

Control of buffet onset by plasma-based actuators

NASA Astrophysics Data System (ADS)

Vishnyakov, O. I.; Polivanov, P. A.; Budovskiy, A. D.; Sidorenko, A. A.; Maslov, A. A.

2016-10-01

The paper is devoted to the experimental investigations of the influence of electrical discharges which produces local area of unsteady energy deposition and density variations on transonic flow, namely, buffet onset. Experiments are carried out in T-112 wind tunnel in TsAGI using model of rectangular wing with chord of 200 mm and span 599 mm. The profile of the wing is supercritical airfoil P184-15SR with max thickness 15% of chord length. Experiments were carried out in the range of Mach number 0.73÷0.78 for several angles of attack of the model. The flow around the model was studied by schlieren visualization, surface pressure distribution measurements and Pitot measurements in the wake of the wing using wake rake located downstream of the model. The experimentally data obtained show that excitation of plasma actuator based on spark discharge effectively influence on mean flow and characteristics of shock wave oscillations. It was found that control efficiency depends on frequency of discharge.

Controlling marginally detached divertor plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eldon, David; Kolemen, Egemen; Barton, Joseph L.

A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as T e = 5 eV near the divertor target plate), the resulting T e profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in and it handles ELMing plasmas by using real time D α measurements to remove during-ELM slices from real time T e measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM T e is passed to a PID (proportionalintegral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate. However, the observed bifurcation in plasma conditions at the outer strike point with the ion B ×more » $$\

Controlling marginally detached divertor plasmas

DOE PAGES

Eldon, David; Kolemen, Egemen; Barton, Joseph L.; ...

2017-05-04

A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as T e = 5 eV near the divertor target plate), the resulting T e profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in and it handles ELMing plasmas by using real time D α measurements to remove during-ELM slices from real time T e measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM T e is passed to a PID (proportionalintegral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate. However, the observed bifurcation in plasma conditions at the outer strike point with the ion B ×more » $$\

Isolation of biologically-active exosomes from human plasma.

PubMed

Muller, Laurent; Hong, Chang-Sook; Stolz, Donna B; Watkins, Simon C; Whiteside, Theresa L

2014-09-01

Effects of exosomes present in human plasma on immune cells have not been examined in detail. Immunological studies with plasma-derived exosomes require their isolation by procedures involving ultracentrifugation. These procedures were largely developed using supernatants of cultured cells. To test biologic activities of plasma-derived exosomes, methods are necessary that ensure adequate recovery of exosome fractions free of contaminating larger vesicles, cell fragments and protein/nucleic acid aggregates. Here, an optimized method for exosome isolation from human plasma/serum specimens of normal controls (NC) or cancer patients and its advantages and pitfalls are described. To remove undesirable plasma-contaminating components, ultrafiltration of differentially-centrifuged plasma/serum followed by size-exclusion chromatography prior to ultracentrifugation facilitated the removal of contaminants. Plasma or serum was equally acceptable as a source of exosomes based on the recovered protein levels (in μg protein/mL plasma) and TEM image quality. Centrifugation on sucrose density gradients led to large exosome losses. Fresh plasma was the best source of morphologically-intact exosomes, while the use of frozen/thawed plasma decreased exosome purity but not their biologic activity. Treatments of frozen plasma with DNAse, RNAse or hyaluronidase did not improve exosome purity and are not recommended. Cancer patients' plasma consistently yielded more isolated exosomes than did NCs' plasma. Cancer patients' exosomes also mediated higher immune suppression as evidenced by decreased CD69 expression on responder CD4+ T effector cells. Thus, the described procedure yields biologically-active, morphologically-intact exosomes that have reasonably good purity without large protein losses and can be used for immunological, biomarker and other studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Preliminary Studies on Aerodynamic Control with Direct Current Discharge at Hypersonic Speed

NASA Astrophysics Data System (ADS)

Watanabe, Yasumasa; Takama, Yoshiki; Imamura, Osamu; Watanuki, Tadaharu; Suzuki, Kojiro

A new idea of an aerodynamic control device for hypersonic vehicles using plasma discharges is presented. The effect of DC plasma discharge on a hypersonic flow is examined with both experiments and CFD analyses. It is revealed that the surface pressure upstream of plasma area significantly increases, which would be preferable in realizing a new aerodynamic control devices. Such pressure rise is also observed in the result of analyses of the Navier-Stokes equations with energy addition that simulates the Joule heating of a plasma discharge. It is revealed that the pressure rise due to the existence of the plasma discharge can be qualitatively explained as an effect of Joule heating.

Optimization of High Porosity Thermal Barrier Coatings Generated with a Porosity Former

NASA Astrophysics Data System (ADS)

Medřický, Jan; Curry, Nicholas; Pala, Zdenek; Vilemova, Monika; Chraska, Tomas; Johansson, Jimmy; Markocsan, Nicolaie

2015-04-01

Yttria-stabilized zirconia thermal barrier coatings are extensively used in turbine industry; however, increasing performance requirements have begun to make conventional air plasma sprayed coatings insufficient for future needs. Since the thermal conductivity of bulk material cannot be lowered easily; the design of highly porous coatings may be the most efficient way to achieve coatings with low thermal conductivity. Thus the approach of fabrication of coatings with a high porosity level based on plasma spraying of ceramic particles of dysprosia-stabilized zirconia mixed with polymer particles, has been tested. Both polymer and ceramic particles melt in plasma and after impact onto a substrate they form a coating. When the coating is subjected to heat treatment, polymer burns out and a complex structure of pores and cracks is formed. In order to obtain desired porosity level and microstructural features in coatings; a design of experiments, based on changes in spray distance, powder feeding rate, and plasma-forming atmosphere, was performed. Acquired coatings were evaluated for thermal conductivity and thermo-cyclic fatigue, and their morphology was assessed using scanning electron microscopy. It was shown that porosity level can be controlled by appropriate changes in spraying parameters.

Multichannel reconfigurable measurement system for hot plasma diagnostics based on GEM-2D detector

NASA Astrophysics Data System (ADS)

Wojenski, A. J.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Chernyshova, M.; Czarski, T.; Jablonski, S.; Juszczyk, B.; Zienkiewicz, P.

2015-12-01

In the future magnetically confined fusion research reactors (e.g. ITER tokamak), precise determination of the level of the soft X-ray radiation of plasma with temperature above 30 keV (around 350 mln K) will be very important in plasma parameters optimization. This paper presents the first version of a designed spectrography measurement system. The system is already installed at JET tokamak. Based on the experience gained from the project, the new generation of hardware for spectrography measurements, was designed and also described in the paper. The GEM detector readout structure was changed to 2D in order to perform measurements of i.e. laser generated plasma. The hardware structure of the system was redesigned in order to provide large number of high speed input channels. Finally, this paper also covers the issue of new control software, necessary to set-up a complete system of certain complexity and perform data acquisition. The main goal of the project was to develop a new version of the system, which includes upgraded structure and data transmission infrastructure (i.e. handling large number of measurement channels, high sampling rate).

Characterization of a dielectric barrier discharge in controlled atmosphere

NASA Astrophysics Data System (ADS)

Kogelheide, Friederike; Offerhaus, Björn; Bibinov, Nikita; Bracht, Vera; Smith, Ryan; Lackmann, Jan-Wilm; Awakowicz, Peter; Stapelmann, Katharina; Bimap Team; Aept Team

2016-09-01

Non-thermal atmospheric-pressure plasmas are advantageous for various biomedical applications as they make a contact- and painless therapy possible. Due to the potential medical relevance of such plasma sources further understanding of the chemical and physical impact on biological tissue regarding the efficacy and health-promoting effect is necessary. The knowledge of properties and effects offers the possibility to configure plasmas free of risk for humans. Therefore, tailoring the discharge chemistry in regard to resulting oxidative and nitrosative effects on biological tissue by adjusting different parameters is of growing interest. In order to ensure stable conditions for the characterization of the discharge, the used dielectric barrier discharge was mounted in a vessel. Absolutely calibrated optical emission spectroscopy was carried out to analyze the electron density and the reduced electric field. The rather oxygen-based discharge was tuned towards a more nitrogen-based discharge by adjusting several parameters as reactive nitrogen species are known to promote wound healing. Furthermore, the impact of an ozone-free discharge has to be studied. This work was funded by the German Research Foundation (DFG) with the packet grant PAK 816 `Plasma Cell Interaction in Dermatology'.

Structural and optical properties of arsenic sulfide films synthesized by a novel PECVD-based approach

NASA Astrophysics Data System (ADS)

Mochalov, Leonid; Kudryashov, Mikhail; Logunov, Aleksandr; Zelentsov, Sergey; Nezhdanov, Aleksey; Mashin, Alexandr; Gogova, Daniela; Chidichimo, Giuseppe; De Filpo, Giovanni

2017-11-01

A new plasma-enhanced chemical vapor deposition-based (PECVD) approach for synthesizing of As-S films, with As content in the range 60-40 at.%, is demonstrated. The process has been carried out in a low-temperature Ar-plasma, employing for the first time volatile As and S as precursors. Utilization of inorganic elemental precursors, in contrast to the typically used in CVD metal-organic compounds or volatile hydrides/halides of Va- and VIa-group-elements, gives the possibility to reach the highest quality and purity of the As-S ≿halcogenide films. Quantum-chemical calculations have been performed to gain insight into the PECVD As-S chalcogenide films structure and the mechanism of its formation in the plasma discharge. An additional vibrational band near 650 cm-1 corresponding to cycled 2-dimensional units is observed by Raman spectroscopy. The process developed is cost-efficient one due to the very precise control and the long-term stability of the plasma parameters and it possesses a high potential for large-area applications such as fabrication of miniature integrated optical elements and 2D/3D printing of optical devices.

A novel gate and drain engineered charge plasma tunnel field-effect transistor for low sub-threshold swing and ambipolar nature

NASA Astrophysics Data System (ADS)

Yadav, Dharmendra Singh; Raad, Bhagwan Ram; Sharma, Dheeraj

2016-12-01

In this paper, we focus on the improvement of figures of merit for charge plasma based tunnel field-effect transistor (TFET) in terms of ON-state current, threshold voltage, sub-threshold swing, ambipolar nature, and gate to drain capacitance which provides better channel controlling of the device with improved high frequency response at ultra-low supply voltages. Regarding this, we simultaneously employ work function engineering on the drain and gate electrode of the charge plasma TFET. The use of gate work function engineering modulates the barrier on the source/channel interface leads to improvement in the ON-state current, threshold voltage, and sub-threshold swing. Apart from this, for the first time use of work function engineering on the drain electrode increases the tunneling barrier for the flow of holes on the drain/channel interface, it results into suppression of ambipolar behavior. The lowering of gate to drain capacitance therefore enhanced high frequency parameters. Whereas, the presence of dual work functionality at the gate electrode and over the drain region improves the overall performance of the charge plasma based TFET.

Laser-plasma-based linear collider using hollow plasma channels

DOE PAGES

Schroeder, C. B.; Benedetti, C.; Esarey, E.; ...

2016-03-03

A linear electron–positron collider based on laser-plasma accelerators using hollow plasma channels is considered. Laser propagation and energy depletion in the hollow channel is discussed, as well as the overall efficiency of the laser-plasma accelerator. Example parameters are presented for a 1-TeV and 3-TeV center-of-mass collider based on laser-plasma accelerators.

Plasmapheresis in thrombotic microangiopathy-associated syndromes: review of outcome data derived from clinical trials and open studies.

PubMed

von Baeyer, Hans

2002-08-01

Current reimbursement policy of health insurance for therapeutic plasmapheresis requires proof of efficacy using the concept of evidence-based medicine. The aim of this paper is to review the outcome of plasmapheresis used to treat thrombotic microangiopathy (TMA)-associated syndromes in the last decade to provide scientific evidence to back up reimbursement applications. The strength of evidence of each reviewed study was assessed using the five levels of evidence criteria as defined by the American Society of Hematology in 1996 for assessment of the treatment of immune thrombocytopenia. The level Experimental indication was added for situations where only case reports or small series supported by pathophysiological reasoning are available. The definitions of evidence used in this paper are as follows: Level I, randomized clinical trial with low rates of error (p < 0.01); Level II, randomized clinical trial with high rates of error (p < 0.05); Level III, nonrandomized studies with concurrent control group; Level IV, nonrandomized studies with historical control group; Level V, case series without a control group or expert opinion; and Experimental, case reports and pathophysiological reasoning. The results of this analysis based on the published data is summarized as follows: The indication of plasmapheresis is assigned to Level IV evidence for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS); cancer/chemotherapy-associated TTP/HUS is assigned to Level V evidence; and TTP/HUS refractory to standard plasma exchange and post-bone marrow transplantation TTP/HUS are assigned to Experimental indication. For both subsets, protein A immunoadsorption is reportedly successful. The other TMA-associated syndromes, hemolysis elevated liver enzymes low platelets and HUS in early childhood, are no indication of plasmapheresis. Two randomized clinical trials were performed in order to demonstrate the superiority of plasma exchange/fresh frozen plasma (PEX/FFP) over plasma transfusion in the management of TTP/HUS. The results prove the greater clinical success of the latter type of plasma administration. Standard PEX/FFP has reduced the mortality of TTP/HUS from 94.5% to 13%.