Progress and plan of KSTAR plasma control system upgrade

DOE PAGES

Hahn, Sang-hee; Kim, Y. J.; Penaflor, B. G.; ...

2016-06-01

The plasma control system (PCS) has been one of essential systems in annual KSTAR plasma campaigns: starting from a single-process version in 2008, extensive upgrades are done through the previous 7 years in order to achieve major goals of KSTAR performance enhancement. Here, major implementations are explained in this paper. In consequences of successive upgrades, the present KSTAR PCS is able to achieve ~48 s of 500 kA plasma pulses with full real-time shaping controls and real-time NB power controls. It has become a huge system capable of dealing with 8 separate categories of algorithms, 26 actuators directly controllable duringmore » the shot, and real-time data communication units consisting of +180 analog channels and +600 digital input/outputs through the reflective memory (RFM) network. The next upgrade of the KSTAR PCS is planned in 2015 before the campaign. An overview of the upgrade layout will be given for this paper. The real-time system box is planned to use the CERN MRG-Realtime OS, an ITER-compatible standard operating system. New hardware is developed for faster real-time streaming system for future installations of actuators/diagnostics.« less

1000 X Difference Between Current Displays and Capability of Human Visual System: Payoff Potential for Affordable Defense Systems

DTIC Science & Technology

2000-01-01

second tier technologies: digital micromirror devices (DMD); alternating current gas plasma (ACGP); inorganic electroluminescent (EL, TFEL, AMEL... Micromirror Device (DMD) - Alternating Current Gas Plasma (ACGP) - Electroluminescent (EL, TFEL, AMEL) - Vacuum Fluorescent Display (VFD) - Inorganic Light...Instruments Digital Micromirror Device (DMD) Digital Light Processing technology and another, the Qualcomm/Hughes-JVC CRT/Liquid Crystal Light Valve

Zonal drift velocities of the ionospheric plasma bubbles over brazilian region using oi630nm airglow digital images

NASA Astrophysics Data System (ADS)

Arruda, D. C. S.; Sobral, J. H. A.; Abdu, M. A.; Castilho, V. M.; Takahashi, H.

The zonal drift velocities of the ionospheric plasma bubbles over the Brazilian region are analyzed in this study that is based on OI630nm airglow digital images. These digital images were obtained by an all-sky imager system between October 1998 and August 2000, at Cachoeira Paulista (22.5°S, 45°W), a low latitude region. In this period, 138 nights of OI 630 nm airglow experiments were carried out of which 30 nights detected the ionospheric plasma bubbles. These 30 nights correspond to magnetically quiet days (ΣK_P<24+) and were grouped according approximately to their season. KEY WORDS: Imager System, Ionospheric Plasma Bubbles, Zonal drift velocities, OI630nm.

Campaign for Levitation in LDX

NASA Astrophysics Data System (ADS)

Garnier, D. T.; Hansen, A. K.; Mauel, M. E.; Ortiz, E. E.; Boxer, A. C.; Ellsworth, J. L.; Karim, I.; Kesner, J.; Michael, P. C.; Zhukovsky, A.

2006-10-01

In the past year, preparations have been made for the first flight of the Levitated Dipole Experiment (LDX). LDX, which consists of a 560 kg superconducting coil floating within a 5 m diameter vacuum chamber, is designed to study fusion relevant plasmas confined in a dipole magnetic field. During the spring, a high temperature superconducting levitation coil was integrated into the LDX facility. Testing was undertaken to verify the thermal performance of the coil under expected levitation conditions. In addition, a real-time operating system digital control system was developed that will be used for the levitation control. In July, plasma experiments were conducted with all superconducting magnets in operation. While still supported, roughly 75% of the weight of the floating coil was magnetically lifted by the levitation coil above. A series of plasma experiments were conducted with the same magnetic geometry as will be the case during levitation. During August, the second generation launcher system will be installed. The launcher, which retracts beyond the plasma's last closed field lines during operation, is designed to safely catch the floating coil following an unexpected loss of control. After this installation, levitation experiments will commence.

Digital Holography for in Situ Real-Time Measurement of Plasma-Facing-Component Erosion

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

ThomasJr., C. E.; Granstedt, E. M.; Biewer, Theodore M

2014-01-01

In situ, real time measurement of net plasma-facing-component (PFC) erosion/deposition in a real plasma device is challenging due to the need for good spatial and temporal resolution, sufficient sensitivity, and immunity to fringe-jump errors. Design of a high-sensitivity, potentially high-speed, dual-wavelength CO2 laser digital holography system (nominally immune to fringe jumps) for PFC erosion measurement is discussed.

A digital enzyme-linked immunosorbent assay for ultrasensitive measurement of amyloid-β 1-42 peptide in human plasma with utility for studies of Alzheimer's disease therapeutics.

PubMed

Song, Linan; Lachno, D Richard; Hanlon, David; Shepro, Adam; Jeromin, Andreas; Gemani, Dipika; Talbot, Jayne A; Racke, Margaret M; Dage, Jeffrey L; Dean, Robert A

2016-12-15

Amyloid-β 1-42 peptide (Aβ 1-42 ) is associated with plaque formation in the brain of patients with Alzheimer's disease (AD). Pharmacodynamic studies of AD therapeutics that lower the concentrations of Aβ 1-42 in peripheral blood require highly sensitive assays for its measurement. A digital enzyme-linked immunosorbent assay (ELISA) using single molecule array (Simoa) technology has been developed that provides improved sensitivity compared with conventional ELISA methods using the same antibody reagents. A sensitive digital ELISA for measurement of Aβ 1-42 using antibodies 3D6 and 21F12 was developed. Assay performance was evaluated by repeated testing of pooled human plasma and buffer diluent quality control samples to determine relative accuracy, intra- and inter-assay precision, limit of detection (LOD), lower limit of quantification (LLOQ), dilutional linearity, and spike recovery. The optimized assay was used to quantify Aβ 1-42 in clinical samples from patients treated with the β-site amyloid precursor protein cleaving enzyme 1 inhibitor LY2886721. The prototype assay measured Aβ 1-42 with an LOD of 0.3 pg/ml and an LLOQ of 2.8 pg/ml in plasma, calibrated using an Aβ 1-42 peptide standard from Fujirebio. Assay precision was acceptable with intra- and inter-assay coefficients of variation both being ≤10%. Dilutional linearity was demonstrated in sample diluent and immunodepleted human plasma. Analyte spike recovery ranged from 51% to 93% with a mean of 80%. This assay was able to quantify Aβ 1-42 in all of the 84 clinical samples tested. A rapid reduction in levels of Aβ 1-42 was detected within 1 h after drug treatment, and a dose-dependent decrease of Aβ 1-42 levels was also observed over the time course of sample collection. This digital ELISA has potential utility in clinical applications for quantification of Aβ 1-42 in plasma where high sensitivity and precision are required.

Feedback Control of Resistive Wall Modes in Slowly Rotating DIII-D Plasmas

NASA Astrophysics Data System (ADS)

Okabayashi, M.; Chance, M. S.; Takahashi, H.; Garofalo, A. M.; Reimerdes, H.; in, Y.; Chu, M. S.; Jackson, G. L.; La Haye, R. J.; Strait, E. J.

2006-10-01

In slowly rotating plasmas on DIII-D, the requirement of RWM control feedback have been identified, using a MHD code along with measured power supply characteristics. It was found that a small time delay is essential for achieving high beta if no rotation stabilization exists. The overall system delay or the band pass time constant should be in the range of 0.4 of the RWM growth time. Recently the control system was upgraded using twelve linear audio amplifiers and a faster digital control system, reducing the time-delay from 600 to 100 μs. The advantage has been clearly observed when the RWMs excited by ELMs were effectively controlled by feedback even if the rotation transiently slowed nearly to zero. This study provides insight on stability in the low- rotation plasmasw with balanced NBI in DIII-D and also in ITER.

Applications of digital processing for noise removal from plasma diagnostics

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

Kane, R.J.; Candy, J.V.; Casper, T.A.

1985-11-11

The use of digital signal techniques for removal of noise components present in plasma diagnostic signals is discussed, particularly with reference to diamagnetic loop signals. These signals contain noise due to power supply ripple in addition to plasma characteristics. The application of noise canceling techniques, such as adaptive noise canceling and model-based estimation, will be discussed. The use of computer codes such as SIG is described. 19 refs., 5 figs.

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.

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.

A comparison of QuantStudio™ 3D Digital PCR and ARMS-PCR for measuring plasma EGFR T790M mutations of NSCLC patients.

PubMed

Feng, Qin; Gai, Fei; Sang, Yaxiong; Zhang, Jie; Wang, Ping; Wang, Yue; Liu, Bing; Lin, Dongmei; Yu, Yang; Fang, Jian

2018-01-01

The AURA3 clinical trial has shown that advanced non-small cell lung cancer (NSCLC) patients with EGFR T790M mutations in circulating tumor DNA (ctDNA) could benefit from osimertinib. The aim of this study was to assess the usefulness of QuantStudio™ 3D Digital PCR System platform for the detection of plasma EGFR T790M mutations in NSCLC patients, and compare the performances of 3D Digital PCR and ARMS-PCR. A total of 119 Chinese patients were enrolled in this study. Mutant allele frequency of plasma EGFR T790M was detected by 3D Digital PCR, then 25 selected samples were verified by ARMS-PCR and four of them were verified by next generation sequencing (NGS). In total, 52.94% (69/119) had EGFR T790M mutations detected by 3D Digital PCR. In 69 positive samples, the median mutant allele frequency (AF) was 1.09% and three cases presented low concentration (AF <0.1%). Limited by the amount of plasma DNA, 17 samples (AF <2.5%) and eight samples (T790M-) were selected for verification by ARMS-PCR. Four of those samples were verified by NGS as a third verification method. Among the selected 17 positive cases, ten samples presented mutant allele frequency <0.5%, and seven samples presented intermediate mutant allele frequency (0.5% AF 2.5%). However, only three samples (3/17) were identified as positive by ARMS-PCR, namely, P6 (AF =1.09%), P7 (AF =2.09%), and P8 (AF =2.21%). It is worth mentioning that sample P9 (AF =2.05%, analyzed by 3D Digital PCR) was identified as T790M- by ARMS-PCR. Four samples were identified as T790M+ by both NGS and 3D Digital PCR, and typically three samples (3/4) presented at a low ratio (AF <0.5%). Our study demonstrated that 3D Digital PCR is a novel method with high sensitivity and specificity to detect EGFR T790M mutation in plasma.

A comparison of QuantStudio™ 3D Digital PCR and ARMS-PCR for measuring plasma EGFR T790M mutations of NSCLC patients

PubMed Central

Sang, Yaxiong; Zhang, Jie; Wang, Ping; Wang, Yue; Liu, Bing; Lin, Dongmei; Yu, Yang; Fang, Jian

2018-01-01

Background The AURA3 clinical trial has shown that advanced non-small cell lung cancer (NSCLC) patients with EGFR T790M mutations in circulating tumor DNA (ctDNA) could benefit from osimertinib. Purpose The aim of this study was to assess the usefulness of QuantStudio™ 3D Digital PCR System platform for the detection of plasma EGFR T790M mutations in NSCLC patients, and compare the performances of 3D Digital PCR and ARMS-PCR. Patients and methods A total of 119 Chinese patients were enrolled in this study. Mutant allele frequency of plasma EGFR T790M was detected by 3D Digital PCR, then 25 selected samples were verified by ARMS-PCR and four of them were verified by next generation sequencing (NGS). Results In total, 52.94% (69/119) had EGFR T790M mutations detected by 3D Digital PCR. In 69 positive samples, the median mutant allele frequency (AF) was 1.09% and three cases presented low concentration (AF <0.1%). Limited by the amount of plasma DNA, 17 samples (AF <2.5%) and eight samples (T790M-) were selected for verification by ARMS-PCR. Four of those samples were verified by NGS as a third verification method. Among the selected 17 positive cases, ten samples presented mutant allele frequency <0.5%, and seven samples presented intermediate mutant allele frequency (0.5% AF 2.5%). However, only three samples (3/17) were identified as positive by ARMS-PCR, namely, P6 (AF =1.09%), P7 (AF =2.09%), and P8 (AF =2.21%). It is worth mentioning that sample P9 (AF =2.05%, analyzed by 3D Digital PCR) was identified as T790M- by ARMS-PCR. Four samples were identified as T790M+ by both NGS and 3D Digital PCR, and typically three samples (3/4) presented at a low ratio (AF <0.5%). Conclusion Our study demonstrated that 3D Digital PCR is a novel method with high sensitivity and specificity to detect EGFR T790M mutation in plasma. PMID:29403309

Public Data Set: Impedance of an Intense Plasma-Cathode Electron Source for Tokamak Plasma Startup

DOE Data Explorer

Hinson, Edward T. [University of Wisconsin-Madison] (ORCID:000000019713140X); Barr, Jayson L. [University of Wisconsin-Madison] (ORCID:0000000177685931); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609)

2016-05-31

This data set contains openly-documented, machine readable digital research data corresponding to figures published in E.T. Hinson et al., 'Impedance of an Intense Plasma-Cathode Electron Source for Tokamak Plasma Startup,' Physics of Plasmas 23, 052515 (2016).

Highly Sensitive Droplet Digital PCR Method for Detection of EGFR-Activating Mutations in Plasma Cell-Free DNA from Patients with Advanced Non-Small Cell Lung Cancer.

PubMed

Zhu, Guanshan; Ye, Xin; Dong, Zhengwei; Lu, Ya Chao; Sun, Yun; Liu, Yi; McCormack, Rose; Gu, Yi; Liu, Xiaoqing

2015-05-01

Epidermal growth factor receptor (EGFR) mutation testing in plasma cell-free DNA from lung cancer patients is an emerging clinical tool. However, compared with tissue testing, the sensitivity of plasma testing is not yet satisfactory because of the highly fragmented nature of plasma cell-free DNA, low fraction of tumor DNA, and limitations of available detection technologies. We therefore developed a highly sensitive and specific droplet digital PCR method for plasma EGFR mutation (exon19 deletions and L858R) testing. Plasma from 86 EGFR-tyrosine kinase inhibitor-naive lung cancer patients was tested and compared with EGFR mutation status of matched tumor tissues tested by amplification refractory mutation system. By using EGFR mutation-positive cell DNA, we optimized the droplet digital PCR assays to reach 0.04% sensitivity. The plasma testing sensitivity and specificity, compared with the matched tumor tissues tested by amplification refractory mutation system, were 81.82% (95% CI, 59.72%-94.81%) and 98.44% (95% CI, 91.60%-99.96%), respectively, for exon19 deletions, with 94.19% concordance rate (κ = 0.840; 95% CI, 0.704-0.976; P < 0.0001), whereas they were 80.00% (95% CI, 51.91%-95.67%) and 95.77% (95% CI, 88.14%-99.12%), respectively, for L858R, with 93.02% concordance rate (κ = 0.758; 95% CI, 0.571-0.945; P < 0.0001). The reported highly sensitive and specific droplet digital PCR assays for EGFR mutation detection have potential in clinical blood testing. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

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.

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

D.A. Gates; J.R. Ferron; M. Bell

In 2003, the NSTX plasma control system was used for plasma shape control using real-time equilibrium reconstruction (using the rtEFIT code - J. Ferron, et al., Nucl. Fusion 38 1055 (1998)). rtEFIT is now in routine use for plasma boundary control [D. A. Gates, et al., submitted to Nuclear Fusion (2005)]. More recently, the system has been upgraded to support feedback control of the resistive wall mode (RWM). This paper describes the hardware and software improvements that were made in support of these physics requirements. The real-time data acquisition system now acquires 352 channels of data at 5kHz for eachmore » NSTX plasma discharge. The latency for the data acquisition, which uses the FPDP (Front Panel Data Port) protocol, is measured to be {approx}8 microseconds. A Stand-Alone digitizer (SAD), designed at PPPL, along with an FPDP Input multiplexing module (FIMM) allows for simple modular upgrades. An interface module was built to interface between the FPDP output of the NSTX control system and the legacy Power Conversion link (PCLINK) used for communicating with the PPPL power supplies (first used for TFTR). Additionally a module has been built for communicating with the switching power amplifiers (SPA) recently installed on NSTX. In addition to the hardware developments, the control software [D. Mastrovito, Fusion Eng. And Design 71 65 (2004)] on the NSTX control system has been upgraded. The control computer is an eight processor (8x333MHz G4) built by Sky Computers (Helmsford, MA). The device driver software for the hardware described above will be discussed, as well as the new control algorithms that have been developed to control the switching power supplies for RWM control. An important initial task in RWM feedback is to develop a reliable mode detection algorithm.« less

EGFR mutation detection in ctDNA from NSCLC patient plasma: A cross-platform comparison of leading technologies to support the clinical development of AZD9291.

PubMed

Thress, Kenneth S; Brant, Roz; Carr, T Hedley; Dearden, Simon; Jenkins, Suzanne; Brown, Helen; Hammett, Tracey; Cantarini, Mireille; Barrett, J Carl

2015-12-01

To assess the ability of different technology platforms to detect epidermal growth factor receptor (EGFR) mutations, including T790M, from circulating tumor DNA (ctDNA) in advanced non-small cell lung cancer (NSCLC) patients. A comparison of multiple platforms for detecting EGFR mutations in plasma ctDNA was undertaken. Plasma samples were collected from patients entering the ongoing AURA trial (NCT01802632), investigating the safety, tolerability, and efficacy of AZD9291 in patients with EGFR-sensitizing mutation-positive NSCLC. Plasma was collected prior to AZD9291 dosing but following clinical progression on a previous EGFR-tyrosine kinase inhibitor (TKI). Extracted ctDNA was analyzed using two non-digital platforms (cobas(®) EGFR Mutation Test and therascreen™ EGFR amplification refractory mutation system assay) and two digital platforms (Droplet Digital™ PCR and BEAMing digital PCR [dPCR]). Preliminary assessment (38 samples) was conducted using all four platforms. For EGFR-TKI-sensitizing mutations, high sensitivity (78-100%) and specificity (93-100%) were observed using tissue as a non-reference standard. For the T790M mutation, the digital platforms outperformed the non-digital platforms. Subsequent assessment using 72 additional baseline plasma samples was conducted using the cobas(®) EGFR Mutation Test and BEAMing dPCR. The two platforms demonstrated high sensitivity (82-87%) and specificity (97%) for EGFR-sensitizing mutations. For the T790M mutation, the sensitivity and specificity were 73% and 67%, respectively, with the cobas(®) EGFR Mutation Test, and 81% and 58%, respectively, with BEAMing dPCR. Concordance between the platforms was >90%, showing that multiple platforms are capable of sensitive and specific detection of EGFR-TKI-sensitizing mutations from NSCLC patient plasma. The cobas(®) EGFR Mutation Test and BEAMing dPCR demonstrate a high sensitivity for T790M mutation detection. Genomic heterogeneity of T790M-mediated resistance may explain the reduced specificity observed with plasma-based detection of T790M mutations versus tissue. These data support the use of both platforms in the AZD9291 clinical development program. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Measurements and Simulations of Surface Dielectric Barrier Discharges Used as Plasma Actuators

NASA Technical Reports Server (NTRS)

Hoskinson, Alan R.

2012-01-01

This report is a Ph.D. dissertation performed under NRA cooperative agreement and submitted as part of the final report. Asymmetric surface dielectric barrier discharges (DBDs) have shown promise for use as aerodynamic actuators for active flow control. In this project we studied DBD actuators experimentally and numerically. Our DBDs used a symmetric triangular high voltage waveform to generate plasma in atmospheric pressure air. Time-averaged measurements indicated that the induced force of a single barrier actuator design (one electrode insulated from the plasma) can be increased exponentially above the results of previous studies by decreasing both the length and thickness of the electrode exposed to the plasma. This increased force may allow these devices to control flow separation in a wider range of flow environments. Experiments using an intensified digital camera to examine the plasma on time scales of a few nanoseconds showed that, in addition to the previously-observed filamentary and jet-like plasma structures, discharges with very thin exposed electrodes exhibited a weak but constant plasma immediately adjacent to those electrodes. In double-barrier actuators (both electrodes insulated), decreasing the diameter of the narrower electrode lead to increasing forces, and recorded images showed the simultaneous existence of both filamentary and jet-like plasma structures. The development and application of a time-dependent, two-dimensional computational fluid plasma model has aided in understanding the detailed physics of surface DBDs at all-time scales. For simulated single-barrier discharges, the model qualitatively reproduced the filamentary and jet-like micro-discharge structures. The model was somewhat successful in reproducing the observed characteristics of double-barrier actuators. For both actuator geometries, the model indicated that the majority of the forces induced on the neutral gas occur in between micro-discharges as the plasmas decay.

Real-time sensing and gas jet mitigation of VDEs on Alcator C-Mod

NASA Astrophysics Data System (ADS)

Granetz, R. S.; Wolfe, S. M.; Izzo, V. A.; Reinke, M. L.; Terry, J. L.; Hughes, J. W.; Zhurovich, K.; Whyte, D. G.; Bakhtiari, M.; Wurden, G.

2006-10-01

Experiments have been carried out in Alcator C-Mod to test the effectiveness of gas jet disruption mitigation of VDEs with real-time detection and triggering by the C-Mod digital plasma control system (DPCS). The DPCS continuously computes the error in the plasma vertical position from the magnetics diagnostics. When this error exceeds an adjustable preset value, the DPCS triggers the gas jet valve (with a negligible latency time). The high-pressure gas (argon) only takes a few milliseconds to enter the vacuum chamber and begin affecting the plasma, but this is comparable to the VDE timescale on C-Mod. Nevertheless, gas jet injection reduced the halo current, increased the radiated power fraction, and reduced the heating of the divertor compared to unmitigated disruptions, but not quite as well as in earlier mitigation experiments with vertically stable plasmas. Presumably a faster overall response time would be beneficial, and several ways to achieve this will also be discussed.

ZaP-HD: High Energy Density Z-Pinch Plasmas using Sheared Flow Stabilization

NASA Astrophysics Data System (ADS)

Golingo, R. P.; Shumlak, U.; Nelson, B. A.; Claveau, E. L.; Doty, S. A.; Forbes, E. G.; Hughes, M. C.; Kim, B.; Ross, M. P.; Weed, J. R.

2015-11-01

The ZaP-HD flow Z-pinch project investigates scaling the flow Z-pinch to High Energy Density Plasma, HEDP, conditions by using sheared flow stabilization. ZaP used a single power supply to produce 100 cm long Z-pinches that were quiescent for many radial Alfven times and axial flow-through times. The flow Z-pinch concept provides an approach to achieve HED plasmas, which are dimensionally large and persist for extended durations. The ZaP-HD device replaces the single power supply from ZaP with two separate power supplies to independently control the plasma flow and current in the Z-pinch. Equilibrium is determined by diagnostic measurements of the density with interferometry and digital holography, the plasma flow and temperature with passive spectroscopy, the magnetic field with surface magnetic probes, and plasma emission with optical imaging. The diagnostics fully characterize the plasma from its initiation in the coaxial accelerator, through the pinch, and exhaust from the assembly region. The plasma evolution is modeled with high resolution codes: Mach2, WARPX, and NIMROD. Experimental results and scaling analyses are presented. This work is supported by grants from the U.S. Department of Energy and the U.S. National Nuclear Security Administration.

Clinical Utility of Circulating Tumor DNA for Molecular Assessment and Precision Medicine in Pancreatic Cancer.

PubMed

Takai, Erina; Totoki, Yasushi; Nakamura, Hiromi; Kato, Mamoru; Shibata, Tatsuhiro; Yachida, Shinichi

2016-01-01

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies. The genomic landscape of the PDAC genome features four frequently mutated genes (KRAS, CDKN2A, TP53, and SMAD4) and dozens of candidate driver genes altered at low frequency, including potential clinical targets. Circulating cell-free DNA (cfDNA) is a promising resource to detect molecular characteristics of tumors, supporting the concept of "liquid biopsy".We determined the mutational status of KRAS in plasma cfDNA using multiplex droplet digital PCR in 259 patients with PDAC, retrospectively. Furthermore, we constructed a novel modified SureSelect-KAPA-Illumina platform and an original panel of 60 genes. We then performed targeted deep sequencing of cfDNA in 48 patients who had ≥1 % mutant allele frequencies of KRAS in plasma cfDNA.Droplet digital PCR detected KRAS mutations in plasma cfDNA in 63 of 107 (58.9 %) patients with inoperable tumors. Importantly, potentially targetable somatic mutations were identified in 14 of 48 patients (29.2 %) examined by cfDNA sequencing.Our two-step approach with plasma cfDNA, combining droplet digital PCR and targeted deep sequencing, is a feasible clinical approach. Assessment of mutations in plasma cfDNA may provide a new diagnostic tool, assisting decisions for optimal therapeutic strategies for PDAC patients.

Evaluation of digital PCR for detecting low-level EGFR mutations in advanced lung adenocarcinoma patients: a cross-platform comparison study

PubMed Central

Liu, Bing; Li, Lei; Huang, Lixia; Li, Shaoli; Rao, Guanhua; Yu, Yang; Zhou, Yanbin

2017-01-01

Emerging evidence has indicated that circulating tumor DNA (ctDNA) from plasma could be used to analyze EGFR mutation status for NSCLC patients; however, due to the low level of ctDNA in plasma, highly sensitive approaches are required to detect low frequency mutations. In addition, the cutoff for the mutation abundance that can be detected in tumor tissue but cannot be detected in matched ctDNA is still unknown. To assess a highly sensitive method, we evaluated the use of digital PCR in the detection of EGFR mutations in tumor tissue from 47 advanced lung adenocarcinoma patients through comparison with NGS and ARMS. We determined the degree of concordance between tumor tissue DNA and paired ctDNA and analyzed the mutation abundance relationship between them. Digital PCR and Proton had a high sensitivity (96.00% vs. 100%) compared with that of ARMS in the detection of mutations in tumor tissue. Digital PCR outperformed Proton in identifying more low abundance mutations. The ctDNA detection rate of digital PCR was 87.50% in paired tumor tissue with a mutation abundance above 5% and 7.59% in paired tumor tissue with a mutation abundance below 5%. When the DNA mutation abundance of tumor tissue was above 3.81%, it could identify mutations in paired ctDNA with a high sensitivity. Digital PCR will help identify alternative methods for detecting low abundance mutations in tumor tissue DNA and plasma ctDNA. PMID:28978074

Development of alternative plasma sources for cavity ring-down measurements of mercury.

PubMed

Duan, Yixiang; Wang, Chuji; Scherrer, Susan T; Winstead, Christopher B

2005-08-01

We have been exploring innovative technologies for elemental and hyperfine structure measurements using cavity ring-down spectroscopy (CRDS) combined with various plasma sources. A laboratory CRDS system utilizing a tunable dye laser is employed in this work to demonstrate the feasibility of the technology. An in-house fabricated sampling system is used to generate aerosols from solution samples and introduce the aerosols into the plasma source. The ring-down signals are monitored using a photomultiplier tube and recorded using a digital oscilloscope interfaced to a computer. Several microwave plasma discharge devices are tested for mercury CRDS measurement. Various discharge tubes have been designed and tested to reduce background interference and increase the sample path length while still controlling turbulence generated from the plasma gas flow. Significant background reduction has been achieved with the implementation of the newly designed tube-shaped plasma devices, which has resulted in a detection limit of 0.4 ng/mL for mercury with the plasma source CRDS. The calibration curves obtained in this work readily show that linearity over 2 orders of magnitude can be obtained with plasma-CRDS for mercury detection. In this work, the hyperfine structure of mercury at the experimental plasma temperatures is clearly identified. We expect that plasma source cavity ring-down spectroscopy will provide enhanced capabilities for elemental and isotopic measurements.

Luminescent characteristics study of Mather-type dense plasma focus and applications to short-wavelength optical pumping. Final technical report, 1 May 1984-30 September 1985

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

Kim, K.K.

A Mather-type dense plasma focus (MDPF) system was designed, built, and tested specifically to study its luminescent characteristics and to assess its potential as a new light source of high-energy, short-wavelength lasers. The luminescence study of MDPF showed that the conversion efficiency from the electrical input to the optical output energies is at least 50%, up to the time the plasma compression is complete. Using the system, for the first time as an optical pump, laser activities were successfully obtained from a variety of liquid organic dyes. Diagnostic capabilities included an optical multichannel analyzer system complete with a computer control,more » a nitrogen-pumped tunable dye-laser system, a high-speed streak/framing camera, a digital laser energy meter, voltage and current probes, and a computer-based data-acquisition system.« less

Validation of a Plasma-Based Comprehensive Cancer Genotyping Assay Utilizing Orthogonal Tissue- and Plasma-Based Methodologies.

PubMed

Odegaard, Justin I; Vincent, John J; Mortimer, Stefanie; Vowles, James V; Ulrich, Bryan C; Banks, Kimberly C; Fairclough, Stephen R; Zill, Oliver A; Sikora, Marcin; Mokhtari, Reza; Abdueva, Diana; Nagy, Rebecca J; Lee, Christine E; Kiedrowski, Lesli A; Paweletz, Cloud P; Eltoukhy, Helmy; Lanman, Richard B; Chudova, Darya I; Talasaz, AmirAli

2018-04-24

Purpose: To analytically and clinically validate a circulating cell-free tumor DNA sequencing test for comprehensive tumor genotyping and demonstrate its clinical feasibility. Experimental Design: Analytic validation was conducted according to established principles and guidelines. Blood-to-blood clinical validation comprised blinded external comparison with clinical droplet digital PCR across 222 consecutive biomarker-positive clinical samples. Blood-to-tissue clinical validation comprised comparison of digital sequencing calls to those documented in the medical record of 543 consecutive lung cancer patients. Clinical experience was reported from 10,593 consecutive clinical samples. Results: Digital sequencing technology enabled variant detection down to 0.02% to 0.04% allelic fraction/2.12 copies with ≤0.3%/2.24-2.76 copies 95% limits of detection while maintaining high specificity [prevalence-adjusted positive predictive values (PPV) >98%]. Clinical validation using orthogonal plasma- and tissue-based clinical genotyping across >750 patients demonstrated high accuracy and specificity [positive percent agreement (PPAs) and negative percent agreement (NPAs) >99% and PPVs 92%-100%]. Clinical use in 10,593 advanced adult solid tumor patients demonstrated high feasibility (>99.6% technical success rate) and clinical sensitivity (85.9%), with high potential actionability (16.7% with FDA-approved on-label treatment options; 72.0% with treatment or trial recommendations), particularly in non-small cell lung cancer, where 34.5% of patient samples comprised a directly targetable standard-of-care biomarker. Conclusions: High concordance with orthogonal clinical plasma- and tissue-based genotyping methods supports the clinical accuracy of digital sequencing across all four types of targetable genomic alterations. Digital sequencing's clinical applicability is further supported by high rates of technical success and biomarker target discovery. Clin Cancer Res; 1-11. ©2018 AACR. ©2018 American Association for Cancer Research.

Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas.

PubMed

Ross, M P; Shumlak, U

2016-10-01

The ZaP-HD flow Z-pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma (plasma with pressures exceeding 1 Mbar) and fusion reactor conditions. The Z-pinch is a linear plasma confinement geometry in which the plasma carries axial electric current and is confined by its self-induced magnetic field. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii (≈1 mm). Radial and axial plasma electron density structure is measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD's DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 × 10 20 m -2 with spatial resolution near 10 μm. This paper presents the first application of Fresnel transform reconstruction as an analysis technique for a plasma diagnostic, and it analyzes the method's accuracy through study of synthetic data. It then presents an Abel inversion procedure that utilizes data on both sides of a Z-pinch local number density profile to maximize profile symmetry. Error estimation and Abel inversion are applied to the measured data.

Reproducibility of Digital PCR Assays for Circulating Tumor DNA Analysis in Advanced Breast Cancer

PubMed Central

Hrebien, Sarah; O’Leary, Ben; Beaney, Matthew; Schiavon, Gaia; Fribbens, Charlotte; Bhambra, Amarjit; Johnson, Richard; Turner, Nicholas

2016-01-01

Circulating tumor DNA (ctDNA) analysis has the potential to allow non-invasive analysis of tumor mutations in advanced cancer. In this study we assessed the reproducibility of digital PCR (dPCR) assays of circulating tumor DNA in a cohort of patients with advanced breast cancer and assessed delayed plasma processing using cell free DNA preservative tubes. We recruited a cohort of 96 paired samples from 71 women with advanced breast cancer who had paired blood samples processed either immediately or delayed in preservative tubes with processing 48–72 hours after collection. Plasma DNA was analysed with multiplex digital PCR (mdPCR) assays for hotspot mutations in PIK3CA, ESR1 and ERBB2, and for AKT1 E17K. There was 94.8% (91/96) agreement in mutation calling between immediate and delayed processed tubes, kappa 0.88 95% CI 0.77–0.98). Discordance in mutation calling resulted from low allele frequency and likely stochastic effects. In concordant samples there was high correlation in mutant copies per ml plasma (r2 = 0.98; p<0.0001). There was elevation of total cell free plasma DNA concentrations in 10.3% of delayed processed tubes, although overall quantification of total cell free plasma DNA had similar prognostic effects in immediate (HR 3.6) and delayed (HR 3.0) tubes. There was moderate agreement in changes in allele fraction between sequential samples in quantitative mutation tracking (r = 0.84, p = 0.0002). Delayed processing of samples using preservative tubes allows for centralized ctDNA digital PCR mutation screening in advanced breast cancer. The potential of preservative tubes in quantitative mutation tracking requires further research. PMID:27760227

Reproducibility of Digital PCR Assays for Circulating Tumor DNA Analysis in Advanced Breast Cancer.

PubMed

Hrebien, Sarah; O'Leary, Ben; Beaney, Matthew; Schiavon, Gaia; Fribbens, Charlotte; Bhambra, Amarjit; Johnson, Richard; Garcia-Murillas, Isaac; Turner, Nicholas

2016-01-01

Circulating tumor DNA (ctDNA) analysis has the potential to allow non-invasive analysis of tumor mutations in advanced cancer. In this study we assessed the reproducibility of digital PCR (dPCR) assays of circulating tumor DNA in a cohort of patients with advanced breast cancer and assessed delayed plasma processing using cell free DNA preservative tubes. We recruited a cohort of 96 paired samples from 71 women with advanced breast cancer who had paired blood samples processed either immediately or delayed in preservative tubes with processing 48-72 hours after collection. Plasma DNA was analysed with multiplex digital PCR (mdPCR) assays for hotspot mutations in PIK3CA, ESR1 and ERBB2, and for AKT1 E17K. There was 94.8% (91/96) agreement in mutation calling between immediate and delayed processed tubes, kappa 0.88 95% CI 0.77-0.98). Discordance in mutation calling resulted from low allele frequency and likely stochastic effects. In concordant samples there was high correlation in mutant copies per ml plasma (r2 = 0.98; p<0.0001). There was elevation of total cell free plasma DNA concentrations in 10.3% of delayed processed tubes, although overall quantification of total cell free plasma DNA had similar prognostic effects in immediate (HR 3.6) and delayed (HR 3.0) tubes. There was moderate agreement in changes in allele fraction between sequential samples in quantitative mutation tracking (r = 0.84, p = 0.0002). Delayed processing of samples using preservative tubes allows for centralized ctDNA digital PCR mutation screening in advanced breast cancer. The potential of preservative tubes in quantitative mutation tracking requires further research.

Characterization of a linear device developed for research on advanced plasma imaging and dynamicsa)

NASA Astrophysics Data System (ADS)

Chung, J.; Lee, K. D.; Seo, D. C.; Nam, Y. U.; Choi, M. C.

2010-10-01

Within the scope of long term research on imaging diagnostics for steady-state plasmas and understanding of edge plasma physics through diagnostics with conventional spectroscopic methods, we have constructed a linear electron cyclotron resonance (ECR) plasma device named Research on Advanced Plasma Imaging and Dynamics (RAPID). It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. Here, a 6 kW 2.45 GHz magnetron is used to produce steady-state hydrogen, helium, and argon plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). In order to achieve the highest possible plasma performance within the limited input parameters, wall conditioning experiments were carried out. Chamber bake-out was achieved with heating coils that were wound covering the vessel, and long-pulse electron cyclotron heating discharge cleaning was also followed after 4 days of bake-out. A uniform bake-out temperature (150 °C) was achieved by wrapping the vessel in high temperature thermal insulation textile and by controlling the heating coil current using a digital control system. The partial pressure changes were observed using a residual gas analyzer, and a total system pressure of 5×10-8 Torr was finally reached. Diagnostic systems including a millimeter-wave interferometer, a high resolution survey spectrometer, a Langmuir probe, and an ultrasoft x-ray detector were used to provide the evidence that the plasma performance was improved as we desired. In this work, we present characterization of the RAPID device for various system conditions and configurations.

Real-time digital filtering, event triggering, and tomographic reconstruction of JET soft x-ray data (abstract)

NASA Astrophysics Data System (ADS)

Edwards, A. W.; Blackler, K.; Gill, R. D.; van der Goot, E.; Holm, J.

1990-10-01

Based upon the experience gained with the present soft x-ray data acquisition system, new techniques are being developed which make extensive use of digital signal processors (DSPs). Digital filters make 13 further frequencies available in real time from the input sampling frequency of 200 kHz. In parallel, various algorithms running on further DSPs generate triggers in response to a range of events in the plasma. The sawtooth crash can be detected, for example, with a delay of only 50 μs from the onset of the collapse. The trigger processor interacts with the digital filter boards to ensure data of the appropriate frequency is recorded throughout a plasma discharge. An independent link is used to pass 780 and 24 Hz filtered data to a network of transputers. A full tomographic inversion and display of the 24 Hz data is carried out in real time using this 15 transputer array. The 780 Hz data are stored for immediate detailed playback following the pulse. Such a system could considerably improve the quality of present plasma diagnostic data which is, in general, sampled at one fixed frequency throughout a discharge. Further, it should provide valuable information towards designing diagnostic data acquisition systems for future long pulse operation machines when a high degree of real-time processing will be required, while retaining the ability to detect, record, and analyze events of interest within such long plasma discharges.

Public Data Set: Non-inductively Driven Tokamak Plasmas at Near-Unity βt in the Pegasus Toroidal Experiment

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

Reusch, Joshua A.; Bodner, Grant M.; Bongard, Michael W.

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in J.A. Reusch et al., 'Non-inductively Driven Tokamak Plasmas at Near-Unity βt in the Pegasus Toroidal Experiment,' Phys. Plasmas 25, 056101 (2018).

Applications of Digital and Optoelectronic Circuits to Electrothermal- Chemical Gun System Facilities

DTIC Science & Technology

1993-03-01

1991; Katulka et al. 1991; Zielinski and Renaud 1992; Powell and Zielinski 1992; Hummer et al. 1992). The electrical plasma is formed on the inside...charge amplifiers, and UPS control systems. 11" CD C)C GD A CJU t In~ 12 6. REFERENCES Bunte, S. W., R. A. Beyer, and A. E. Zielinski . "Temperature...State Devices). Cleveland, OH: Addison-Wesley Publishing Company, Inc. 1988. Katulka, 0. L., H. Burden, A. Zielinski , and K. White. "Electrical Energy

Plasma cell quantification in bone marrow by computer-assisted image analysis.

PubMed

Went, P; Mayer, S; Oberholzer, M; Dirnhofer, S

2006-09-01

Minor and major criteria for the diagnosis of multiple meloma according to the definition of the WHO classification include different categories of the bone marrow plasma cell count: a shift from the 10-30% group to the > 30% group equals a shift from a minor to a major criterium, while the < 10% group does not contribute to the diagnosis. Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of this study was (i) to establish a digital image analysis system able to quantify bone marrow plasma cells and (ii) to evaluate two quantification techniques in bone marrow trephines i.e. computer-assisted digital image analysis and conventional light-microscopic evaluation. The results were compared regarding inter-observer variation of the obtained results. Eighty-seven patients, 28 with multiple myeloma, 29 with monoclonal gammopathy of undetermined significance, and 30 with reactive plasmocytosis were included in the study. Plasma cells in H&E- and CD138-stained slides were quantified by two investigators using light-microscopic estimation and computer-assisted digital analysis. The sets of results were correlated with rank correlation coefficients. Patients were categorized according to WHO criteria addressing the plasma cell content of the bone marrow (group 1: 0-10%, group 2: 11-30%, group 3: > 30%), and the results compared by kappa statistics. The degree of agreement in CD138-stained slides was higher for results obtained using the computer-assisted image analysis system compared to light microscopic evaluation (corr.coeff. = 0.782), as was seen in the intra- (corr.coeff. = 0.960) and inter-individual results correlations (corr.coeff. = 0.899). Inter-observer agreement for categorized results (SM/PW: kappa 0.833) was in a high range. Computer-assisted image analysis demonstrated a higher reproducibility of bone marrow plasma cell quantification. This might be of critical importance for diagnosis, clinical management and prognostics when plasma cell numbers are low, which makes exact quantifications difficult.

Fringe-jump corrected far infrared tangential interferometer/polarimeter for a real-time density feedback control system of NSTX plasmasa)

NASA Astrophysics Data System (ADS)

Juhn, J.-W.; Lee, K. C.; Hwang, Y. S.; Domier, C. W.; Luhmann, N. C.; Leblanc, B. P.; Mueller, D.; Gates, D. A.; Kaita, R.

2010-10-01

The far infrared tangential interferometer/polarimeter (FIReTIP) of the National Spherical Torus Experiment (NSTX) has been set up to provide reliable electron density signals for a real-time density feedback control system. This work consists of two main parts: suppression of the fringe jumps that have been prohibiting the plasma density from use in the direct feedback to actuators and the conceptual design of a density feedback control system including the FIReTIP, control hardware, and software that takes advantage of the NSTX plasma control system (PCS). By investigating numerous shot data after July 2009 when the new electronics were installed, fringe jumps in the FIReTIP are well characterized, and consequently the suppressing algorithms are working properly as shown in comparisons with the Thomson scattering diagnostic. This approach is also applicable to signals taken at a 5 kHz sampling rate, which is a fundamental constraint imposed by the digitizers providing inputs to the PCS. The fringe jump correction algorithm, as well as safety and feedback modules, will be included as submodules either in the gas injection system category or a new category of density in the PCS.

Mirror Langmuir probe: a technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode.

PubMed

LaBombard, B; Lyons, L

2007-07-01

A new method for the real-time evaluation of the conditions in a magnetized plasma is described. The technique employs an electronic "mirror Langmuir probe" (MLP), constructed from bipolar rf transistors and associated high-bandwidth electronics. Utilizing a three-state bias wave form and active feedback control, the mirror probe's I-V characteristic is continuously adjusted to be a scaled replica of the "actual" Langmuir electrode immersed in a plasma. Real-time high-bandwidth measurements of the plasma's electron temperature, ion saturation current, and floating potential can thereby be obtained using only a single electrode. Initial tests of a prototype MLP system are reported, proving the concept. Fast-switching metal-oxide-semiconductor field-effect transistors produce the required three-state voltage bias wave form, completing a full cycle in under 1 mus. Real-time outputs of electron temperature, ion saturation current, and floating potential are demonstrated, which accurately track an independent computation of these values from digitally stored I-V characteristics. The MLP technique represents a significant improvement over existing real-time methods, eliminating the need for multiple electrodes and sampling all three plasma parameters at a single spatial location.

Welding arc and plasma studies using real time, multipass holographic interferometry

NASA Technical Reports Server (NTRS)

Deason, Vance

1987-01-01

Flow visualization of the plasma process in a welding arc is being studied with a multipass Argon ion interferometer. High speed movies at 10,000 frames per/sec are taken. The multipass interferometer and several interferograms of the plasma near the electrode of the welding are given. Digitization of the fringes is currently done by hand.

Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic evaluation.

PubMed

El Taieb, Moustafa A; Ibrahim, Hassan; Nada, Essam A; Seif Al-Din, Mai

2017-01-01

Alopecia areata is a common cause of nonscarring alopecia that occurs in a patchy, confluent, or diffuse pattern. Dermoscopy is a noninvasive technique for the clinical diagnosis of many skin diseases. Topical minoxidil solution 5% and platelet rich plasma are important modalities used in treatment of alopecia areata. We aimed to evaluate the efficacy of PRP versus topical minoxidil 5% in the treatment of AA by clinical evaluation and trichoscopic examination. Ninety patients were allocated into three groups; the first was treated with topical minoxidil 5% solution, the second with platelets rich plasma injections, and the third with placebo. Diagnosis and follow up were done by serial digital camera photography of lesions and dermoscopic scan before and every 1 month after treatment for 3 months. Patients treated with minoxidil 5% and platelets rich plasma both have significant hair growth than placebo (p < .05). Patients treated with platelets rich plasma had an earlier response in the form of hair regrowth, reduction in short vellus hair and dystrophic hair unlike patients treated with minoxidil and control (p < .05). In conclusion, platelets rich plasma is more effective in the treatment of alopecia areata than topical minoxidil 5% as evaluated by clinical and trichoscopic examination. © 2016 Wiley Periodicals, Inc.

Electrowetting on plasma-deposited fluorocarbon hydrophobic films for biofluid transport in microfluidics

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

Bayiati, P.; Tserepi, A.; Petrou, P. S.

2007-05-15

The present work focuses on the plasma deposition of fluorocarbon (FC) films on surfaces and the electrostatic control of their wettability (electrowetting). Such films can be employed for actuation of fluid transport in microfluidic devices, when deposited over patterned electrodes. Here, the deposition was performed using C{sub 4}F{sub 8} and the plasma parameters that permit the creation of films with optimized properties desirable for electrowetting were established. The wettability of the plasma-deposited surfaces was characterized by means of contact angle measurements (in the static and dynamic mode). The thickness of the deposited films was probed in situ by means ofmore » spectroscopic ellipsometry, while the surface roughness was provided by atomic force microscopy. These plasma-deposited FC films in combination with silicon nitride, a material of high dielectric constant, were used to create a dielectric structure that requires reduced voltages for successful electrowetting. Electrowetting experiments using protein solutions were conducted on such optimized dielectric structures and were compared with similar structures bearing commercial spin-coated Teflon registered amorphous fluoropolymer (AF) film as the hydrophobic top layer. Our results show that plasma-deposited FC films have desirable electrowetting behavior and minimal protein adsorption, a requirement for successful transport of biological solutions in 'digital' microfluidics.« less

Digital filter polychromator for Thomson scattering applications

NASA Astrophysics Data System (ADS)

Solokha, V.; Kurskiev, G.; Mukhin, E.; Tolstyakov, S.; Babinov, N.; Bazhenov, A.; Bukreev, I.; Dmitriev, A.; Kochergin, M.; Koval, A.; Litvinov, A.; Masyukevich, S.; Razdobarin, A.; Samsonov, D.; Semenov, V.; Solovey, V.; Chernakov, P.; Chernakov, Al; Chernakov, An

2018-02-01

Incoherent Thomson scattering diagnostics (TS) is a proven technique capable of reliable and robust instantaneous measurement of electron temperature (T e) and density (n e) local values in wide area of plasma physics experiments: from hall-effect thrusters to tokamaks and stellarators. The TS cross section is very low (˜ 6.7 × 10-30 m2), and the corresponding TS signals, measured in fusion experiments, are usually of ˜10-15 of incident power. This paper represents 6 (7) channel filter polychromator equipped with avalanche photodiodes and low-noise preamplifiers. The incorporated ADC system (5 GS/s, 12 bit) provides digital optical output preventing acquisition system from electromagnetic interferences. The calibration techniques and T e, n e with corresponding errors measured in Globus-M plasma are given for the digital polychromator test-bench.

Analysis of human blood plasma cell-free DNA fragment size distribution using EvaGreen chemistry based droplet digital PCR assays.

PubMed

Fernando, M Rohan; Jiang, Chao; Krzyzanowski, Gary D; Ryan, Wayne L

2018-04-12

Plasma cell-free DNA (cfDNA) fragment size distribution provides important information required for diagnostic assay development. We have developed and optimized droplet digital PCR (ddPCR) assays that quantify short and long DNA fragments. These assays were used to analyze plasma cfDNA fragment size distribution in human blood. Assays were designed to amplify 76,135, 490 and 905 base pair fragments of human β-actin gene. These assays were used for fragment size analysis of plasma cell-free, exosome and apoptotic body DNA obtained from normal and pregnant donors. The relative percentages for 76, 135, 490 and 905 bp fragments from non-pregnant plasma and exosome DNA were 100%, 39%, 18%, 5.6% and 100%, 40%, 18%,3.3%, respectively. The relative percentages for pregnant plasma and exosome DNA were 100%, 34%, 14%, 23%, and 100%, 30%, 12%, 18%, respectively. The relative percentages for non-pregnant plasma pellet (obtained after 2nd centrifugation step) were 100%, 100%, 87% and 83%, respectively. Non-pregnant Plasma cell-free and exosome DNA share a unique fragment distribution pattern which is different from pregnant donor plasma and exosome DNA fragment distribution indicating the effect of physiological status on cfDNA fragment size distribution. Fragment distribution pattern for plasma pellet that includes apoptotic bodies and nuclear DNA was greatly different from plasma cell-free and exosome DNA. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Increasing Plasma Parameters using Sheared Flow Stabilization of a Z-Pinch

NASA Astrophysics Data System (ADS)

Shumlak, Uri

2016-10-01

Recent experiments on the ZaP Flow Z-Pinch at the University of Washington have been successful in compressing the plasma column to smaller radii, producing the predicted increases in plasma density (1018 cm-3), temperature (200 eV), and magnetic fields (4 T), while maintaining plasma stability for many Alfven times (over 40 μs) using sheared plasma flows. These results indicate the suitability of the device as a discovery science platform for astrophysical and high energy density plasma research, and keeps open a possible path to achieving burning plasma conditions in a compact fusion device. Long-lived Z-pinch plasmas have been produced with dimensions of 1 cm radius and 100 cm long that are stabilized by sheared axial flows for over 1000 Alfven radial transit times. The observed plasma stability is coincident with the presence of a sheared flow as measured by time-resolved multi-chord ion Doppler spectroscopy applied to impurity ion radiation. These measurements yield insights into the evolution of the velocity profile and show that the stabilizing behavior of flow shear agrees with theoretical calculations and 2-D MHD computational simulations. The flow shear value, extent, and duration are shown to be consistent with theoretical models of the plasma viscosity, which places a design constraint on the maximum axial length of a sheared flow stabilized Z-pinch. Measurements of the magnetic field topology indicate simultaneous azimuthal symmetry and axial uniformity along the entire 100 cm length of the Z-pinch plasma. Separate control of plasma acceleration and compression have increased the accessible plasma parameters and have generated stable plasmas with radii below 0.5 cm, as measured with a high resolution digital holographic interferometer. This work was supported by Grants from U.S. DOE, NNSA, and ARPA-E.

Fast data transmission in dynamic data acquisition system for plasma diagnostics

NASA Astrophysics Data System (ADS)

Byszuk, Adrian; Poźniak, Krzysztof; Zabołotny, Wojciech M.; Kasprowicz, Grzegorz; Wojeński, Andrzej; Cieszewski, Radosław; Juszczyk, Bartłomiej; Kolasiński, Piotr; Zienkiewicz, Paweł; Chernyshova, Maryna; Czarski, Tomasz

2014-11-01

This paper describes architecture of a new data acquisition system (DAQ) targeted mainly at plasma diagnostic experiments. Modular architecture, in combination with selected hardware components, allows for straightforward reconfiguration of the whole system, both offline and online. Main emphasis will be put into the implementation of data transmission subsystem in said system. One of the biggest advantages of described system is modular architecture with well defined boundaries between main components: analog frontend (AFE), digital backplane and acquisition/control software. Usage of a FPGA chips allows for a high flexibility in design of analog frontends, including ADC <--> FPGA interface. Data transmission between backplane boards and user software was accomplished with the use of industry-standard PCI Express (PCIe) technology. PCIe implementation includes both FPGA firmware and Linux device driver. High flexibility of PCIe connections was accomplished due to use of configurable PCIe switch. Whenever it's possible, described DAQ system tries to make use of standard off-the-shelf (OTF) components, including typical x86 CPU & motherboard (acting as PCIe controller) and cabling.

Autologous conditioned plasma as therapy of tendon and ligament lesions in seven horses

PubMed Central

Georg, Rindermann; Maria, Cislakova; Gisela, Arndt

2010-01-01

This case report describes the intralesional application of autologous conditioned plasma (ACP) in seven horses as treatment of severe tendinitis of the superficial digital flexor tendon, deep digital flexor tendon, or desmitis of the inferior check ligament. Follow-up data of the horses revealed a positive outcome in 10 to 13 months post injury. All horses treated with ACP were either performing in their previous work-load or were back in full training. Further studies with long-term follow-up will have to be performed to support these clinical intermediate-term observations. PMID:20458161

Design of a digital holography system for PFC erosion measurements on Proto-MPEX.

PubMed

Thomas, C E Tommy; Biewer, T M; Baylor, L R; Combs, S K; Meitner, S J; Rapp, J; Hillis, D L; Granstedt, E M; Majeski, R; Kaita, R

2016-11-01

A project has been started at ORNL to develop a dual-wavelength digital holography system for plasma facing component erosion measurements on prototype material plasma exposure experiment. Such a system will allow in situ real-time measurements of component erosion. Initially the system will be developed with one laser, and first experimental laboratory measurements will be made with the single laser system. In the second year of development, a second CO 2 laser will be added and measurements with the dual wavelength system will begin. Adding the second wavelength allows measurements at a much longer synthetic wavelength.

Single-molecule detection of epidermal growth factor receptor mutations in plasma by microfluidics digital PCR in non-small cell lung cancer patients.

PubMed

Yung, Tony K F; Chan, K C Allen; Mok, Tony S K; Tong, Joanna; To, Ka-Fai; Lo, Y M Dennis

2009-03-15

We aim to develop a digital PCR-based method for the quantitative detection of the two common epidermal growth factor receptor (EGFR) mutations (in-frame deletion at exon 19 and L858R at exon 21) in the plasma and tumor tissues of patients suffering from non-small cell lung cancers. These two mutations account for >85% of clinically important EGFR mutations associated with responsiveness to tyrosine kinase inhibitors. DNA samples were analyzed using a microfluidics system that simultaneously performed 9,180 PCRs at nanoliter scale. A single-mutant DNA molecule in a clinical specimen could be detected and the quantities of mutant and wild-type sequences were precisely determined. Exon 19 deletion and L858R mutation were detectable in 6 (17%) and 9 (26%) of 35 pretreatment plasma samples, respectively. When compared with the sequencing results of the tumor samples, the sensitivity and specificity of plasma EGFR mutation analysis were 92% and 100%, respectively. The plasma concentration of the mutant sequences correlated well with the clinical response. Decreased concentration was observed in all patients with partial or complete clinical remission, whereas persistence of mutation was observed in a patient with cancer progression. In one patient, tyrosine kinase inhibitor was stopped after an initial response and the tumor-associated EGFR mutation reemerged 4 weeks after stopping treatment. The sensitive detection and accurate quantification of low abundance EGFR mutations in tumor tissues and plasma by microfluidics digital PCR would be useful for predicting treatment response, monitoring disease progression and early detection of treatment failure associated with acquired drug resistance.

Comparing whole slide digital images versus traditional glass slides in the detection of common microscopic features seen in dermatitis

PubMed Central

Vyas, Nikki S.; Markow, Michael; Prieto-Granada, Carlos; Gaudi, Sudeep; Turner, Leslie; Rodriguez-Waitkus, Paul; Messina, Jane L.; Jukic, Drazen M.

2016-01-01

Background: The quality and limitations of digital slides are not fully known. We aimed to estimate intrapathologist discrepancy in detecting specific microscopic features on glass slides and digital slides created by scanning at ×20. Methods: Hematoxylin and eosin and periodic acid–Schiff glass slides were digitized using the Mirax Scan (Carl Zeiss Inc., Germany). Six pathologists assessed 50–71 digital slides. We recorded objective magnification, total time, and detection of the following: Mast cells; eosinophils; plasma cells; pigmented macrophages; melanin in the epidermis; fungal bodies; neutrophils; civatte bodies; parakeratosis; and sebocytes. This process was repeated using the corresponding glass slides after 3 weeks. The diagnosis was not required. Results: The mean time to assess digital slides was 176.77 s and 137.61 s for glass slides (P < 0.001, 99% confidence interval [CI]). The mean objective magnification used to detect features using digital slides was 18.28 and 14.07 for glass slides (P < 0.001, 99.99% CI). Parakeratosis, civatte bodies, pigmented macrophages, melanin in the epidermis, mast cells, eosinophils, plasma cells, and neutrophils, were identified at lower objectives on glass slides (P = 0.023–0.001, 95% CI). Average intraobserver concordance ranged from κ = 0.30 to κ = 0.78. Features with poor to fair average concordance were: Melanin in the epidermis (κ = 0.15–0.58); plasma cells (κ = 0.15–0.49); and neutrophils (κ = 0.12–0.48). Features with moderate average intrapathologist concordance were: parakeratosis (κ = 0.21–0.61); civatte bodies (κ = 0.21–0.71); pigment-laden macrophages (κ = 0.34–0.66); mast cells (κ = 0.29–0.78); and eosinophils (κ = 0.31–0.79). The average intrapathologist concordance was good for sebocytes (κ = 0.51–1.00) and fungal bodies (κ = 0.47–0.76). Conclusions: Telepathology using digital slides scanned at ×20 is sufficient for detection of histopathologic features routinely encountered in dermatitis cases, though less efficient than glass slides. PMID:27563489

Effects of in vivo applications of peripheral blood-derived mesenchymal stromal cells (PB-MSCs) and platlet-rich plasma (PRP) on experimentally injured deep digital flexor tendons of sheep.

PubMed

Martinello, Tiziana; Bronzini, Ilaria; Perazzi, Anna; Testoni, Stefania; De Benedictis, Gulia Maria; Negro, Alessandro; Caporale, Giovanni; Mascarello, Francesco; Iacopetti, Ilaria; Patruno, Marco

2013-02-01

Tendon injuries, degenerative tendinopathies, and overuse tendinitis are common in races horses. Novel therapies aim to restore tendon functionality by means of cell-based therapy, growth factor delivery, and tissue engineering approaches. This study examined the use of autologous mesenchymal stromal cells derived from peripheral blood (PB-MSCs), platelet-rich plasma (PRP) and a combination of both for ameliorating experimental lesions on deep digital flexor tendons (DDFT) of Bergamasca sheep. In particular, testing the combination of blood-derived MSCs and PRP in an experimental animal model represents one of the few studies exploring a putative synergistic action of these treatments. Effectiveness of treatments was evaluated at 30 and 120 days comparing clinical, ultrasonographic, and histological features together with immunohistochemical expression of collagen types 1 and 3, and cartilage oligomeric matrix protein (COMP). Significant differences were found between treated groups and their corresponding controls (placebo) regarding tendon morphology and extracellular matrix (ECM) composition. However, our results indicate that the combined use of PRP and MSCs did not produce an additive or synergistic regenerative response and highlighted the predominant effect of MSCs on tendon healing, enhanced tissue remodeling and improved structural organization. Copyright © 2012 Orthopaedic Research Society.

Public Data Set: H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment

DOE Data Explorer

Thome, Kathreen E. [University of Wisconsin-Madison; Oak Ridge Associated Universities] (ORCID:0000000248013922); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Barr, Jayson L. [University of Wisconsin-Madison] (ORCID:0000000177685931); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Kriete, David M. [University of Wisconsin-Madison] (ORCID:0000000236572911); Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

2016-09-30

This data set contains openly-documented, machine readable digital research data corresponding to figures published in K.E. Thome et al., 'H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment,' Nucl. Fusion 57, 022018 (2017).

Progress on Pre-Stage Magnetic Coil to Enhance Helicon Mode Excitation and Data Acquisition Software on the Helicon Plasma Experiment (HPX)

NASA Astrophysics Data System (ADS)

Sherman, Justin; Azzari, Phillip; Crilly, P. B.; Duke-Tinson, Omar; James, Royce W.; Karama, Jackson; Page, E. J.; Schlank, Carter; Zuniga, Jonathan

2014-10-01

CGAPL is conducting small investigations in plasma physics and magneto-hydrodynamics buoy positioning. For data management, we are developing capability to analyze/digitize data with a National Instruments Data Acquisition board, 2 MS/s sampling rate (long time scale), and an Express Octopus card, 125 MS/s sampling rate (short scale). Sampling at 12 bits precision, we use LabVIEW as a programing language; GUIs will control variables in 1 or more concurrent runs and monitor of diagnostics. HPX utilizes high density (1013 cm3 up), low pressure (.01 T) Ar gas (fill pressure: on 104 mTorr order). Helicon/W Mode plasmas become a diagnostics test-bed for other investigations and a tool for future spacecraft propulsion devices. Plasmas created by directing energy into gas-filled Pyrex tube; power supply and matching box, up to 250 W power in 20-100 MHz frequencies, provide energy to ignite. Uniform magnetic field needed to reach the W-Mode. We employ an electromagnet to B-field while an acceleration coil positions plasma in vacuum chamber, facilitating analysis. Initial field requirements and accuracy calibration have been completed. Progress on development and implementation of probes and DAQ/GUI system will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY13.

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.

Accurate quantitation of circulating cell-free mitochondrial DNA in plasma by droplet digital PCR.

PubMed

Ye, Wei; Tang, Xiaojun; Liu, Chu; Wen, Chaowei; Li, Wei; Lyu, Jianxin

2017-04-01

To establish a method for accurate quantitation of circulating cell-free mitochondrial DNA (ccf-mtDNA) in plasma by droplet digital PCR (ddPCR), we designed a ddPCR method to determine the copy number of ccf-mtDNA by amplifying mitochondrial ND1 (MT-ND1). To evaluate the sensitivity and specificity of the method, a recombinant pMD18-T plasmid containing MT-ND1 sequences and mtDNA-deleted (ρ 0 ) HeLa cells were used, respectively. Subsequently, different plasma samples were prepared for ddPCR to evaluate the feasibility of detecting plasma ccf-mtDNA. In the results, the ddPCR method showed high sensitivity and specificity. When the DNA was extracted from plasma prior to ddPCR, the ccf-mtDNA copy number was higher than that measured without extraction. This difference was not due to a PCR inhibitor, such as EDTA-Na 2 , an anti-coagulant in plasma, because standard EDTA-Na 2 concentration (5 mM) did not significantly inhibit ddPCR reactions. The difference might be attributable to plasma exosomal mtDNA, which was 4.21 ± 0.38 copies/μL of plasma, accounting for ∼19% of plasma ccf-mtDNA. Therefore, ddPCR can quickly and reliably detect ccf-mtDNA from plasma with a prior DNA extraction step, providing for a more accurate detection of ccf-mtDNA. The direct use of plasma as a template in ddPCR is suitable for the detection of exogenous cell-free nucleic acids within plasma, but not of nucleic acids that have a vesicle-associated form, such as exosomal mtDNA. Graphical Abstract Designs of the present work. *: Module 1, #: Module 2, &: Module 3.

Inward transport of a toroidally confined plasma subject to strong radial electric fields

NASA Technical Reports Server (NTRS)

Roth, J. R.; Krawczonek, W. M.; Powers, E. J.; Hong, J.; Kim, Y. H.

1977-01-01

Digitally implemented spectral analysis techniques were used to investigate the frequency-dependent fluctuation-induced particle transport across a toroidal magnetic field. When the electric field pointed radially inward, the transport was inward and a significant enhancement of the plasma density and confinement time resulted.

A comparison of ARMS-Plus and droplet digital PCR for detecting EGFR activating mutations in plasma

PubMed Central

Zhang, Xinxin; Chang, Ning; Yang, Guohua; Zhang, Yong; Ye, Mingxiang; Cao, Jing; Xiong, Jie; Han, Zhiping; Wu, Shuo; Shang, Lei; Zhang, Jian

2017-01-01

In this study, we introduce a novel amplification refractory mutation system (ARMS)-based assay, namely ARMS-Plus, for the detection of epidermal growth factor receptor (EGFR) mutations in plasma samples. We evaluated the performance of ARMS-Plus in comparison with droplet digital PCR (ddPCR) and assessed the significance of plasma EGFR mutations in predicting efficacy of EGFR-tyrosine kinase inhibitor (TKI) regimen. A total of 122 advanced non-small cell lung cancer (NSCLC) patients were enrolled in this study. The tumor tissue samples from these patients were evaluated by conventional ARMS PCR method to confirm their EGFR mutation status. For the 116 plasma samples analyzed by ARMS-Plus, the sensitivity, specificity, and concordance rate were 77.27% (34/44), 97.22% (70/72), and 89.66% (104/116; κ=0.77, P<0.0001), respectively. Among the 71 plasma samples analyzed by both ARMS-Plus and ddPCR, ARMS-Plus showed a higher sensitivity than ddPCR (83.33% versus 70.83%). The presence of EGFR activating mutations in plasma was not associated with the response to EGFR-TKI, although further validation with a larger cohort is required to confirm the correlation. Collectively, the performance of ARMS-Plus and ddPCR are comparable. ARMS-Plus could be a potential alternative to tissue genotyping for the detection of plasma EGFR mutations in NSCLC patients. PMID:29340107

Digital PCR analysis of maternal plasma for noninvasive detection of sickle cell anemia.

PubMed

Barrett, Angela N; McDonnell, Thomas C R; Chan, K C Allen; Chitty, Lyn S

2012-06-01

Cell-free fetal DNA (cffDNA) constitutes approximately 10% of the cell-free DNA in maternal plasma and is a suitable source of fetal genetic material for noninvasive prenatal diagnosis (NIPD). The objective of this study was to determine the feasibility of using digital PCR for NIPD in pregnancies at risk of sickle cell anemia. Minor-groove binder (MGB) TaqMan probes were designed to discriminate between wild-type hemoglobin A and mutant (hemoglobin S) alleles encoded by the HBB (hemoglobin, beta) gene in cffDNA isolated from maternal plasma samples obtained from pregnancies at risk of sickle cell anemia. The fractional fetal DNA concentration was assessed in male-bearing pregnancies with a digital PCR assay for the Y chromosome-specific marker DYS14. In pregnancies with a female fetus, a panel of biallelic insertion/deletion polymorphism (indel) markers was developed for the quantification of the fetal DNA fraction. We used digital real-time PCR to analyze the dosage of the variant encoding hemoglobin S relative to that encoding wild-type hemoglobin A. The sickle cell genotype was correctly determined in 82% (37 of 45) of male fetuses and 75% (15 of 20) of female fetuses. Mutation status was determined correctly in 100% of the cases (25 samples) with fractional fetal DNA concentrations >7%. The panel of indels was informative in 65% of the female-bearing pregnancies. Digital PCR can be used to determine the genotype of fetuses at risk for sickle cell anemia. Optimization of the fractional fetal DNA concentration is essential. More-informative indel markers are needed for this assay's comprehensive use in cases of a female fetus.

Theoretical design and analysis of multivolume digital assays with wide dynamic range validated experimentally with microfluidic digital PCR.

PubMed

Kreutz, Jason E; Munson, Todd; Huynh, Toan; Shen, Feng; Du, Wenbin; Ismagilov, Rustem F

2011-11-01

This paper presents a protocol using theoretical methods and free software to design and analyze multivolume digital PCR (MV digital PCR) devices; the theory and software are also applicable to design and analysis of dilution series in digital PCR. MV digital PCR minimizes the total number of wells required for "digital" (single molecule) measurements while maintaining high dynamic range and high resolution. In some examples, multivolume designs with fewer than 200 total wells are predicted to provide dynamic range with 5-fold resolution similar to that of single-volume designs requiring 12,000 wells. Mathematical techniques were utilized and expanded to maximize the information obtained from each experiment and to quantify performance of devices and were experimentally validated using the SlipChip platform. MV digital PCR was demonstrated to perform reliably, and results from wells of different volumes agreed with one another. No artifacts due to different surface-to-volume ratios were observed, and single molecule amplification in volumes ranging from 1 to 125 nL was self-consistent. The device presented here was designed to meet the testing requirements for measuring clinically relevant levels of HIV viral load at the point-of-care (in plasma, <500 molecules/mL to >1,000,000 molecules/mL), and the predicted resolution and dynamic range was experimentally validated using a control sequence of DNA. This approach simplifies digital PCR experiments, saves space, and thus enables multiplexing using separate areas for each sample on one chip, and facilitates the development of new high-performance diagnostic tools for resource-limited applications. The theory and software presented here are general and are applicable to designing and analyzing other digital analytical platforms including digital immunoassays and digital bacterial analysis. It is not limited to SlipChip and could also be useful for the design of systems on platforms including valve-based and droplet-based platforms. In a separate publication by Shen et al. (J. Am. Chem. Soc., 2011, DOI: 10.1021/ja2060116), this approach is used to design and test digital RT-PCR devices for quantifying RNA.

Crystal digital droplet PCR for detection and quantification of circulating EGFR sensitizing and resistance mutations in advanced non-small cell lung cancer

PubMed Central

Madic, Jordan; Remon, Jordi; Honoré, Aurélie; Girard, Romain; Rouleau, Etienne; André, Barbara; Besse, Benjamin; Droniou, Magali; Lacroix, Ludovic

2017-01-01

Over the past years, targeted therapies using tyrosine kinase inhibitors (TKI) have led to an increase in progression-free survival and response rate for a subgroup of non-small cell lung cancer (NSCLC) patients harbouring specific gene abnormalities compared with chemotherapy. However long-lasting tumor regression is rarely achieved, due to the development of resistant tumoral subclones, which requires alternative therapeutic approaches. Molecular profile at progressive disease is a challenge for making adaptive treatment decisions. The aim of this study was to monitor EGFR-mutant tumors over time based on the quantity of mutant DNA circulating in plasma (ctDNA), comparing two different methods, Crystal™ Digital™ PCR and Massive Parallel Sequencing (MPS). In plasma circulating cell free DNA (cfDNA) of 61 advanced NSCLC patients we found an overall correlation of 78% between mutated allelic fraction measured by Crystal Digital PCR and MPS. 7 additional samples with sensitizing mutations and 4 additional samples with the resistance mutation were detected with Crystal Digital PCR, but not with MPS. Monitoring levels of both mutation types over time showed a correlation between levels and trends of mutated ctDNA detected and clinical assessment of disease for the 6 patients tested. In conclusion, Crystal Digital PCR exhibited good performance for monitoring mutational status in plasma cfDNA, and also appeared as better suited to the detection of known mutations than MPS in terms of features such as time to results. PMID:28829811

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.

High speed digital holography for density and fluctuation measurements (invited).

PubMed

Thomas, C E; Baylor, L R; Combs, S K; Meitner, S J; Rasmussen, D A; Granstedt, E M; Majeski, R P; Kaita, R

2010-10-01

The state of the art in electro-optics has advanced to the point where digital holographic acquisition of wavefronts is now possible. Holographic wavefront acquisition provides the phase of the wavefront at every measurement point. This can be done with accuracy on the order of a thousandth of a wavelength, given that there is sufficient care in the design of the system. At wave frequencies which are much greater than the plasma frequency, the plasma index of refraction is linearly proportional to the electron density and wavelength, and the measurement of the phase of a wavefront passing through the plasma gives the chord-integrated density directly for all points measured on the wavefront. High-speed infrared cameras (up to ∼40,000 fps at ∼64×4 pixels) with resolutions up to 640×512 pixels suitable for use with a CO(2) laser are readily available, if expensive.

Low-temperature plasma-enhanced atomic layer deposition of 2-D MoS2: large area, thickness control and tuneable morphology.

PubMed

Sharma, Akhil; Verheijen, Marcel A; Wu, Longfei; Karwal, Saurabh; Vandalon, Vincent; Knoops, Harm C M; Sundaram, Ravi S; Hofmann, Jan P; Kessels, W M M Erwin; Bol, Ageeth A

2018-05-10

Low-temperature controllable synthesis of monolayer-to-multilayer thick MoS2 with tuneable morphology is demonstrated by using plasma enhanced atomic layer deposition (PEALD). The characteristic self-limiting ALD growth with a growth-per-cycle of 0.1 nm per cycle and digital thickness control down to a monolayer are observed with excellent wafer scale uniformity. The as-deposited films are found to be polycrystalline in nature showing the signature Raman and photoluminescence signals for the mono-to-few layered regime. Furthermore, a transformation in film morphology from in-plane to out-of-plane orientation of the 2-dimensional layers as a function of growth temperature is observed. An extensive study based on high-resolution transmission electron microscopy is presented to unravel the nucleation mechanism of MoS2 on SiO2/Si substrates at 450 °C. In addition, a model elucidating the film morphology transformation (at 450 °C) is hypothesized. Finally, the out-of-plane oriented films are demonstrated to outperform the in-plane oriented films in the hydrogen evolution reaction for water splitting applications.

Evaluating Multi-Input/Multi-Output Digital Control Systems

NASA Technical Reports Server (NTRS)

Pototzky, Anthony S.; Wieseman, Carol D.; Hoadley, Sherwood T.; Mukhopadhyay, Vivek

1994-01-01

Controller-performance-evaluation (CPE) methodology for multi-input/multi-output (MIMO) digital control systems developed. Procedures identify potentially destabilizing controllers and confirm satisfactory performance of stabilizing ones. Methodology generic and used in many types of multi-loop digital-controller applications, including digital flight-control systems, digitally controlled spacecraft structures, and actively controlled wind-tunnel models. Also applicable to other complex, highly dynamic digital controllers, such as those in high-performance robot systems.

Public Data Set: Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive

DOE Data Explorer

Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Pachicano, Jessica L. [University of Wisconsin-Madison] (ORCID:0000000207255693); Pierren, Christopher [University of Wisconsin-Madison] (ORCID:0000000228289825); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rhodes, Alexander T. [University of Wisconsin-Madison] (ORCID:0000000280735714); Richner, Nathan J. [University of Wisconsin-Madison] (ORCID:0000000155443915); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schaefer, Carolyn E. [University of Wisconsin-Madison] (ORCID:0000000248848727); Weberski, Justin D. [University of Wisconsin-Madison] (ORCID:0000000256267914)

2018-05-22

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in J.M. Perry et al., 'Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive,' accepted for publication in Nuclear Fusion.

RF low-level control for the Linac4 H{sup −} source

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

Butterworth, A., E-mail: andrew.butterworth@cern.ch; Grudiev, A.; Lettry, J.

2015-04-08

The H{sup −} source for the Linac4 accelerator at CERN uses an RF driven plasma for the production of H{sup −}. The RF is supplied by a 2 MHz RF tube amplifier with a maximum power output of 100 kW and a pulse duration of up to 2 ms. The low-level RF signal generation and measurement system has been developed using standard CERN controls electronics in the VME form factor. The RF frequency and amplitude reference signals are generated using separate arbitrary waveform generator channels. The frequency and amplitude are both freely programmable over the duration of the RF pulse, which allowsmore » fine-tuning of the excitation. Measurements of the forward and reverse RF power signals are performed via directional couplers using high-speed digitizers, and permit the estimation of the plasma impedance and deposited power via an equivalent circuit model. The low-level RF hardware and software implementations are described, and experimental results obtained with the Linac4 ion sources in the test stand are presented.« less

Rocket experiment METS Microwave Energy Transmission in Space

NASA Astrophysics Data System (ADS)

Kaya, N.; Matsumoto, H.; Akiba, R.

A METS (Microwave Energy Transmission in Space) rocket experiment is being planned by the SPS (Solar Power Satellite) Working Group at the Institute of Space and Astronautical Science (ISAS) in Japan for the forthcoming International Space Year (ISY), 1992. The METS experiment is an advanced version of our MINIX rocket experiment. This paper describes the conceptual design for the METS rocket experiment. Aims are to verify the feasibility of a newly developed microwave energy transmission system designed for use in space and to study nonlinear effects of the microwave energy beam on space plasma. A high power microwave (936 W) will be transmitted by a new phase-array antenna from a mother rocket to a separate target (daughter rocket) through the Earth's ionospheric plasma. The active phased-array system has the capability of being able to focus the microwave energy at any spatial point by individually controlling the digital phase shifters.

Rocket experiment METS - Microwave Energy Transmission in Space

NASA Astrophysics Data System (ADS)

Kaya, N.; Matsumoto, H.; Akiba, R.

A Microwave Energy Transmission in Space (METS) rocket experiment is being planned by the Solar Power Satellite Working Group at the Institute of Space and Astronautical Science in Japan for the forthcoming International Space Year, 1992. The METS experiment is an advanced version of the previous MINIX rocket experiment (Matsumoto et al., 1990). This paper describes a conceptual design of the METS rocket experiment. It aims at verifying a newly developed microwave energy transmission system for space use and to study nonlinear effects of the microwave energy beam in the space plasma environment. A high power microwave of 936 W will be transmitted by the new phased-array antenna from a mother rocket to a separated target (daughter rocket) through the ionospheric plasma. The active phased-array system has a capability of focusing the microwave energy around any spatial point by controlling the digital phase shifters individually.

Vehicle charging and potential on the STS-3 mission

NASA Technical Reports Server (NTRS)

Williamson, R.

1983-01-01

An electron gun with fast pulse capability was used in the vehicle charging and potential experiment carried on the OSS-1 pallet to study dielectric charging, return current mechanisms, and the techniques required to manage the electrical charging of the orbiter. Return currents and charging of the dielectrics were measured during electron beam emission and plasma characteristics in the payload bay were determined in the absence of electron beam emission. The fast pulse electron generator, charge current probes, spherical retarding potential analyzer, and the digital control interface unit which comprise the experiment are described. Results show that the thrusters produce disturbances which are variable in character and magnitude. Strong ram/wake effects were seen in the ion densities in the bay. Vehicle potentials are variable with respect to the plasma and depend upon location on the vehicle relative to the main engine nozzles, the vehicle attitude, and the direction of the geomagnetic field.

Event and Pulse Node Hardware Design for Nuclear Fusion Experiments

NASA Astrophysics Data System (ADS)

Fortunato, J. C.; Batista, A.; Sousa, J.; Fernandes, H.; Varandas, C. A. F.

2008-04-01

This article presents an event and pulse node hardware module (EPN) developed for use in control and data acquisition (CODAC) in current and upcoming long discharges nuclear fusion experiments. Its purpose is to allow real time event management and trigger distribution. The use of a mixture of digital signal processing and field programmable gate arrays, with fiber optic channels for event broadcast between CODAC nodes, and short length paths between the EPN and CODAC hardware, allows an effective and low latency communication path. This hardware will be integrated in the ISTTOK CODAC to allow long AC plasma discharges.

Nuclear Science Symposium, 19th, and Nuclear Power Systems Symposium, 4th, Miami, Fla., December 6-8, 1972, Proceedings.

NASA Technical Reports Server (NTRS)

1973-01-01

Major topics covered include radiation monitoring instrumentation, nuclear circuits and systems, biomedical applications of nuclear radiation in diagnosis and therapy, plasma research for fusion power, reactor control and instrumentation, nuclear power standards, and applications of digital computers in nuclear power plants. Systems and devices for space applications are described, including the Apollo alpha spectrometer, a position sensitive detection system for UV and X-ray photons, a 4500-volt electron multiplier bias supply for satellite use, spark chamber systems, proportional counters, and other devices. Individual items are announced in this issue.

A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules

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

Dawson, Elizabeth A.; Parkes, Gareth M. B.; Bond, Gary

This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated inmore » the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration.« less

Magnetics and Power System Upgrades for the Pegasus-U Experiment

NASA Astrophysics Data System (ADS)

Preston, R. C.; Bongard, M. W.; Fonck, R. J.; Lewicki, B. T.

2014-10-01

To support the missions of developing local helicity injection startup and exploiting advanced tokamak physics studies at near unity aspect ratio, the proposed Pegasus-U will include expanded magnetic systems and associated power supplies. A new centerstack increases the toroidal field seven times to 1 T and the volt-seconds by a factor of six while maintaining operation at an aspect ratio of 1.2. The poloidal field magnet system is expanded to support improved shape control and robust double or single null divertor operation at the full plasma current of 0.3 MA. An integrated digital control system based on Field Programmable Gate Arrays (FPGAs) provides active feedback control of all magnet currents. Implementation of the FPGAs is achieved with modular noise reducing electronics. The digital feedback controllers replace the existing analog systems and switch multiplexing technology. This will reduce noise sensitivity and allow the operational Ohmic power supply voltage to increase from 2100 V to its maximum capacity of 2400 V. The feedback controller replacement also allows frequency control for ``freewheeling''--stopping the switching for a short interval and allowing the current to coast. The FPGAs assist in optimizing pulse length by having programmable switching events to minimize energy losses. They also allow for more efficient switching topologies that provide improved stored energy utilization, and support increasing the pulse length from 25 ms to 50-100 ms. Work supported by US DOE Grant DE-FG02-96ER54375.

Digital redesign of anti-wind-up controller for cascaded analog system.

PubMed

Chen, Y S; Tsai, J S H; Shieh, L S; Moussighi, M M

2003-01-01

The cascaded conventional anti-wind-up (CAW) design method for integral controller is discussed. Then, the prediction-based digital redesign methodology is utilized to find the new pulse amplitude modulated (PAM) digital controller for effective digital control of the analog plant with input saturation constraint. The desired digital controller is determined from existing or pre-designed CAW analog controller. The proposed method provides a novel methodology for indirect digital design of a continuous-time unity output-feedback system with a cascaded analog controller as in the case of PID controllers for industrial control processes with the presence of actuator saturations. It enables us to implement an existing or pre-designed cascaded CAW analog controller via a digital controller effectively.

Topical local anaesthetics (EMLA) inhibit burn-induced plasma extravasation as measured by digital image colour analysis.

PubMed

Jönsson, A; Mattsson, U; Tarnow, P; Nellgård, P; Cassuto, J

1998-06-01

Amide local anaesthetics have previously been shown to reduce oedema and improve dermal perfusion following experimental burns. Previous studies have used invasive techniques for burn oedema quantification which do not allow continuous monitoring in the same animal. The present study used digital image colour analysis to investigate the effect of topical local anaesthetics on burn-induced extravasation of Evans blue albumin. A standardised full-thickness burn injury (1 x 1 cm) was induced in the abdominal skin of anaesthetised rats. The burn area was subsequently covered with 0.5 g of lidocaine-prilocaine cream 5% (25 mg of each in 1 g; EMLA, ASTRA, Sweden) or placebo cream during the first hour post-burn. One hour after the burn trauma, animals received Evans blue dye intravenously. Skin colour appearances were recorded by macrophotography before the burn and 5, 60. 65, 90, 120, 150, and 180 min post-burn. Colour slides were digitised and colour changes were analysed using the normalised red-green-blue (n-rgb) colour system. Results showed a significant inhibition of Evans blue extravasation between 60 and 180 min post-burn in EMLA-treated animals versus controls. Topical local anaesthetics are potent inhibitors of burn-induced plasma albumin extravasation, probably by direct action on vascular permeability and by inhibition of various steps of the pathophysiological response after burn injury.

Public Data Set: Continuous, Edge Localized Ion Heating During Non-Solenoidal Plasma Startup and Sustainment in a Low Aspect Ratio Tokamak

DOE Data Explorer

Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Barr, Jayson L. [University of Wisconsin-Madison] (ORCID:0000000177685931); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Hinson, Edward T. [University of Wisconsin-Madison] (ORCID:000000019713140X); Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

2017-05-16

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in M.G. Burke et. al., 'Continuous, Edge Localized Ion Heating During Non-Solenoidal Plasma Startup and Sustainment in a Low Aspect Ratio Tokamak,' Nucl. Fusion 57, 076010 (2017).

Circulating Tumor DNA Measurement by Picoliter Droplet-Based Digital PCR and Vemurafenib Plasma Concentrations in Patients with Advanced BRAF-Mutated Melanoma.

PubMed

Garlan, Fanny; Blanchet, Benoit; Kramkimel, Nora; Puszkiel, Alicja; Golmard, Jean-Louis; Noe, Gaelle; Dupin, Nicolas; Laurent-Puig, Pierre; Vidal, Michel; Taly, Valerie; Thomas-Schoemann, Audrey

2017-06-01

Circulating tumor DNA (ctDNA) has been reported as a prognostic marker in melanoma. In BRAF V600-mutant melanoma, a plasma under-exposure to vemurafenib could favor emerging resistance but no biological data are available to support this hypothesis. We aimed to investigate the relationship between vemurafenib plasma concentrations and the ctDNA plasma concentration during follow-up of BRAF-mutated melanoma patients. Eleven patients treated with single-agent vemurafenib for advanced BRAF V600-mutant melanoma were analyzed in an exploratory monocentric study. The vemurafenib plasma concentration was measured by liquid chromatography. ctDNA was extracted from plasma samples and the ctDNA concentration was evaluated using picoliter droplet-based digital PCR with Taqman ® detection probes targeting the BRAF p.V600E/K mutation and wild-type BRAF sequences. At baseline, plasma ctDNA was detectable in 72% (n = 8/11) of patients and the ctDNA concentration decreased in 88% of these patients (n = 7/8) from day (D) 0 to D15 after vemurafenib initiation. During follow-up, an increased ctDNA concentration was detected in nine patients: in five patients, the first increase in ctDNA concentrations followed a decrease in vemurafenib concentrations. More interestingly, an inverse correlation between vemurafenib concentration and ctDNA concentrations was demonstrated (p = 0.026). The ctDNA concentration at baseline was associated with overall survival (hazard ratio = 2.61, 95% CI 1.04-6.56; p = 0.04). This study demonstrates the relevance of vemurafenib plasma monitoring during the follow-up of metastatic melanoma patients. Plasma drug monitoring and ctDNA concentrations could be combined to monitor tumor evolution in melanoma patients treated with anti-BRAF therapies.

RANDOMNESS of Numbers DEFINITION(QUERY:WHAT? V HOW?) ONLY Via MAXWELL-BOLTZMANN CLASSICAL-Statistics(MBCS) Hot-Plasma VS. Digits-Clumping Log-Law NON-Randomness Inversion ONLY BOSE-EINSTEIN QUANTUM-Statistics(BEQS) .

NASA Astrophysics Data System (ADS)

Siegel, Z.; Siegel, Edward Carl-Ludwig

2011-03-01

RANDOMNESS of Numbers cognitive-semantics DEFINITION VIA Cognition QUERY: WHAT???, NOT HOW?) VS. computer-``science" mindLESS number-crunching (Harrel-Sipser-...) algorithmics Goldreich "PSEUDO-randomness"[Not.AMS(02)] mea-culpa is ONLY via MAXWELL-BOLTZMANN CLASSICAL-STATISTICS(NOT FDQS!!!) "hot-plasma" REPULSION VERSUS Newcomb(1881)-Weyl(1914;1916)-Benford(1938) "NeWBe" logarithmic-law digit-CLUMPING/ CLUSTERING NON-Randomness simple Siegel[AMS Joint.Mtg.(02)-Abs. # 973-60-124] algebraic-inversion to THE QUANTUM and ONLY BEQS preferentially SEQUENTIALLY lower-DIGITS CLUMPING/CLUSTERING with d = 0 BEC, is ONLY VIA Siegel-Baez FUZZYICS=CATEGORYICS (SON OF TRIZ)/"Category-Semantics"(C-S), latter intersection/union of Lawvere(1964)-Siegel(1964)] category-theory (matrix: MORPHISMS V FUNCTORS) "+" cognitive-semantics'' (matrix: ANTONYMS V SYNONYMS) yields Siegel-Baez FUZZYICS=CATEGORYICS/C-S tabular list-format matrix truth-table analytics: MBCS RANDOMNESS TRUTH/EMET!!!

Longitudinal study examining the neurotoxicity of occupational exposure to aluminium-containing welding fumes.

PubMed

Buchta, M; Kiesswetter, E; Otto, A; Schaller, K H; Seeber, A; Hilla, W; Windorfer, K; Stork, J; Kuhlmann, A; Gefeller, O; Letzel, S

2003-09-01

The neurotoxicity of occupational exposure to aluminium (Al)-containing welding fumes has been discussed with controversial results. The aim of the longitudinal study was to examine a group of Al welders for significant central nervous changes in comparison with a non-exposed cohort. A group of 98 Al welders (mean age 37 years) in the car-body construction industry, with a median of 6 years of occupational exposure to Al welding fumes, and an education-matched, gender-matched, age-matched control group of 50 car-production workers (mean age 36 years) at the same plant, were included in this longitudinal study. Two cross-sectional studies were done in 1999 and 2001. In the second cross-sectional study 97 welders and 50 controls could be examined. The examination programme consisted, for example, of a standardised anamnesis, focussing on occupational history, education, illnesses, medication, accidents and current alcohol consumption, a physical examination that included neurological status, and the assessment of Al concentration in plasma and urine. The neurobehavioral methods included a symptom questionnaire, modified Q16, and computerised and non-computerised tests: psychomotor performance (steadiness, line tracing, aiming, tapping), verbal intelligence (WST), simple reaction time, digit span, block design (HAWIE), symbol-digit substitution, digit span, switching attention (European neurobehavioral evaluation system, EURO-NES), and standard progressive matrices. The data were analysed by multivariate analysis of covariance (MANCOVA) for repeated measurements with covariates age, education, and carbohydrate-deficient transferrin in plasma (CDT). RESULTS. The median Al urine concentration (mean preshift/postshift) was 52.4 microg/g creatinine (2001) and 57.6 microg/g creatinine (1999). Median respirable air dust was 0.67 mg/m(3) (2001) and 0.47 mg/m(3) (1999). Welders and controls did not report significantly more symptoms in the modified Q16. Furthermore, no significant differences in psychomotor performance and other neurobehavioral tasks, except for reaction time, were seen between welders and non-welders. Regression analyses reveal a significant relationship between reaction time and Al excretion in urine that was confounded by other factors. At present the outcome for reaction time has to be interpreted as a single result. However, as the modified Q16 questionnaire and the rest of the psychomotor performance showed no significant changes, the next cross-sectional study, in 2003, will provide further information on which a final conclusion can be based.

Information Technology Industry 2004

DTIC Science & Technology

2004-01-01

American Chamber of Commerce – Japan Diet Member Mr. Taro Kono Sony Media World NTT DoCoMo Asia Technology Information Program Japan IT...lines by entering consumer electronic markets (plasma and LCD televisions, digital cameras, and digital music players, etc.) with higher profit...in “business to business” sales. BEA Systems and IBM lead sales in this software sub-market. Likewise, Nintendo and Sony continue to dominate the

Total DNA input is a crucial determinant of the sensitivity of plasma cell-free DNA EGFR mutation detection using droplet digital PCR

PubMed Central

Zhao, Jing; Chen, Minjiang; Zhang, Li; Li, Longyun; Wang, Mengzhao

2017-01-01

We evaluated the use of droplet digital PCR (ddPCR) to detect plasma cell-free DNA (cfDNA) epidermal growth factor receptor (EGFR) mutations in advanced non-small cell lung cancer (NSCLC) patients. Compared with tumor-tissue-based detection, the sensitivity of ddPCR for detecting plasma cfDNA tyrosine kinase inhibitor (TKI)-sensitizing EGFR mutations was 61.3%, the specificity was 96.7%, and the consistency rate was 81.4% (?=0.605, 95% confidence interval: 0.501-0.706, p <0.0001). The sensitivity declined from 82.6% to 46.7% with decreasing cfDNA inputs (p=0.028). The plasma cfDNA concentration correlated with gender (males vs.females =11.69 ng/mL vs. 9.508 ng/mL; p=0.044), EGFR mutation status (tumor-tissue EGFR mutation-positive (EGFR M+) vs. EGFR mutation-negative (EGFR M-) = 9.61 ng/mL vs. 12.82 ng/mL; p =0.049) and specimen collection time (=2 years vs. >2 years=13.83 ng/mL vs. 6.575 ng/mL; p <0.001), and was greater in tumor-tissue EGFR M+ / plasma EGFR M+ patients than in tumor-tissue EGFR M+/plasma EGFR M- patients (11.61 vs. 7.73 ng/mL, respectively; p=0.003). Thus total cfDNA input crucially influences the sensitivity of plasma cfDNA EGFR mutation testing with ddPCR. Such analysis could be an effective supplemental test for advanced NSCLC patients. PMID:28052016

Low-to-Medium Power Single Chip Digital Controlled DC-DC Regulator for Point-of-Load Applications

NASA Technical Reports Server (NTRS)

Adell, Philippe C. (Inventor); Bakkaloglu, Bertan (Inventor); Vermeire, Bert (Inventor); Liu, Tao (Inventor)

2015-01-01

A DC-DC converter for generating a DC output voltage includes: a digitally controlled pulse width modulator (DPWM) for controlling a switching power stage to supply a varying voltage to an inductor; and a digital voltage feedback circuit for controlling the DPWM in accordance with a feedback voltage corresponding to the DC output voltage, the digital voltage feedback circuit including: a first voltage controlled oscillator for converting the feedback voltage into a first frequency signal and to supply the first frequency signal to a first frequency discriminator; a second voltage controlled oscillator for converting a reference voltage into a second frequency signal and to supply the second frequency signal to a second frequency discriminator; a digital comparator for comparing digital outputs of the first and second frequency discriminators and for outputting a digital feedback signal; and a controller for controlling the DPWM in accordance with the digital feedback signal.

Droplet digital PCR for detection and quantification of circulating tumor DNA in plasma of head and neck cancer patients.

PubMed

van Ginkel, Joost H; Huibers, Manon M H; van Es, Robert J J; de Bree, Remco; Willems, Stefan M

2017-06-19

During posttreatment surveillance of head and neck cancer patients, imaging is insufficiently accurate for the early detection of relapsing disease. Free circulating tumor DNA (ctDNA) may serve as a novel biomarker for monitoring tumor burden during posttreatment surveillance of these patients. In this exploratory study, we investigated whether low level ctDNA in plasma of head and neck cancer patients can be detected using Droplet Digital PCR (ddPCR). TP53 mutations were determined in surgically resected primary tumor samples from six patients with high stage (II-IV), moderate to poorly differentiated head and neck squamous cell carcinoma (HNSCC). Subsequently, mutation specific ddPCR assays were designed. Pretreatment plasma samples from these patients were examined on the presence of ctDNA by ddPCR using the mutation-specific assays. The ddPCR results were evaluated alongside clinicopathological data. In all cases, plasma samples were found positive for targeted TP53 mutations in varying degrees (absolute quantification of 2.2-422 mutational copies/ml plasma). Mutations were detected in wild-type TP53 background templates of 7667-156,667 copies/ml plasma, yielding fractional abundances of down to 0.01%. Our results show that detection of tumor specific TP53 mutations in low level ctDNA from HNSCC patients using ddPCR is technically feasible and provide ground for future research on ctDNA quantification for the use of diagnostic biomarkers in the posttreatment surveillance of HNSCC patients.

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.

Analytical and Clinical Validation of a Digital Sequencing Panel for Quantitative, Highly Accurate Evaluation of Cell-Free Circulating Tumor DNA

PubMed Central

Zill, Oliver A.; Sebisanovic, Dragan; Lopez, Rene; Blau, Sibel; Collisson, Eric A.; Divers, Stephen G.; Hoon, Dave S. B.; Kopetz, E. Scott; Lee, Jeeyun; Nikolinakos, Petros G.; Baca, Arthur M.; Kermani, Bahram G.; Eltoukhy, Helmy; Talasaz, AmirAli

2015-01-01

Next-generation sequencing of cell-free circulating solid tumor DNA addresses two challenges in contemporary cancer care. First this method of massively parallel and deep sequencing enables assessment of a comprehensive panel of genomic targets from a single sample, and second, it obviates the need for repeat invasive tissue biopsies. Digital SequencingTM is a novel method for high-quality sequencing of circulating tumor DNA simultaneously across a comprehensive panel of over 50 cancer-related genes with a simple blood test. Here we report the analytic and clinical validation of the gene panel. Analytic sensitivity down to 0.1% mutant allele fraction is demonstrated via serial dilution studies of known samples. Near-perfect analytic specificity (> 99.9999%) enables complete coverage of many genes without the false positives typically seen with traditional sequencing assays at mutant allele frequencies or fractions below 5%. We compared digital sequencing of plasma-derived cell-free DNA to tissue-based sequencing on 165 consecutive matched samples from five outside centers in patients with stage III-IV solid tumor cancers. Clinical sensitivity of plasma-derived NGS was 85.0%, comparable to 80.7% sensitivity for tissue. The assay success rate on 1,000 consecutive samples in clinical practice was 99.8%. Digital sequencing of plasma-derived DNA is indicated in advanced cancer patients to prevent repeated invasive biopsies when the initial biopsy is inadequate, unobtainable for genomic testing, or uninformative, or when the patient’s cancer has progressed despite treatment. Its clinical utility is derived from reduction in the costs, complications and delays associated with invasive tissue biopsies for genomic testing. PMID:26474073

Comparison of digital controllers used in magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Kilgore, William A.

1990-01-01

Dynamic systems that were once controlled by analog circuits are now controlled by digital computers. Presented is a comparison of the digital controllers presently used with magnetic suspension and balance systems. The overall responses of the systems are compared using a computer simulation of the magnetic suspension and balance system and the digital controllers. The comparisons include responses to both simulated force and position inputs. A preferred digital controller is determined from the simulated responses.

Could Digital PCR Be an Alternative as a Non-Invasive Prenatal Test for Trisomy 21: A Proof of Concept Study.

PubMed

El Khattabi, Laïla Allach; Rouillac-Le Sciellour, Christelle; Le Tessier, Dominique; Luscan, Armelle; Coustier, Audrey; Porcher, Raphael; Bhouri, Rakia; Nectoux, Juliette; Sérazin, Valérie; Quibel, Thibaut; Mandelbrot, Laurent; Tsatsaris, Vassilis; Vialard, François; Dupont, Jean-Michel

2016-01-01

NIPT for fetal aneuploidy by digital PCR has been hampered by the large number of PCR reactions needed to meet statistical requirements, preventing clinical application. Here, we designed an octoplex droplet digital PCR (ddPCR) assay which allows increasing the number of available targets and thus overcomes statistical obstacles. After technical optimization of the multiplex PCR on mixtures of trisomic and euploid DNA, we performed a validation study on samples of plasma DNA from 213 pregnant women. Molecular counting of circulating cell-free DNA was performed using a mix of hydrolysis probes targeting chromosome 21 and a reference chromosome. The results of our validation experiments showed that ddPCR detected trisomy 21 even when the sample's trisomic DNA content is as low as 5%. In a validation study of plasma samples from 213 pregnant women, ddPCR discriminated clearly between the trisomy 21 and the euploidy groups. Our results demonstrate that digital PCR can meet the requirements for non-invasive prenatal testing of trisomy 21. This approach is technically simple, relatively cheap, easy to implement in a diagnostic setting and compatible with ethical concerns regarding access to nucleotide sequence information. These advantages make it a potential technique of choice for population-wide screening for trisomy 21 in pregnant women.

Novel method to detect microRNAs using chip-based QuantStudio 3D digital PCR.

PubMed

Conte, Davide; Verri, Carla; Borzi, Cristina; Suatoni, Paola; Pastorino, Ugo; Sozzi, Gabriella; Fortunato, Orazio

2015-10-23

Research efforts for the management of cancer, in particular for lung cancer, are directed to identify new strategies for its early detection. MicroRNAs (miRNAs) are a new promising class of circulating biomarkers for cancer detection, but lack of consensus on data normalization methods has affected the diagnostic potential of circulating miRNAs. There is a growing interest in techniques that allow an absolute quantification of miRNAs which could be useful for early diagnosis. Recently, digital PCR, mainly based on droplets generation, emerged as an affordable technology for precise and absolute quantification of nucleic acids. In this work, we described a new interesting approach for profiling circulating miRNAs in plasma samples using a chip-based platform, the QuantStudio 3D digital PCR. The proposed method was validated using synthethic oligonucleotide at serial dilutions in plasma samples of lung cancer patients and in lung tissues and cell lines. Given its reproducibility and reliability, our approach could be potentially applied for the identification and quantification of miRNAs in other biological samples such as circulating exosomes or protein complexes. As chip-digital PCR becomes more established, it would be a robust tool for quantitative assessment of miRNA copy number for diagnosis of lung cancer and other diseases.

Adaptive method for electron bunch profile prediction

DOE PAGES

Scheinker, Alexander; Gessner, Spencer

2015-10-15

We report on an experiment performed at the Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC National Accelerator Laboratory, in which a new adaptive control algorithm, one with known, bounded update rates, despite operating on analytically unknown cost functions, was utilized in order to provide quasi-real-time bunch property estimates of the electron beam. Multiple parameters, such as arbitrary rf phase settings and other time-varying accelerator properties, were simultaneously tuned in order to match a simulated bunch energy spectrum with a measured energy spectrum. Thus, the simple adaptive scheme was digitally implemented using matlab and the experimental physics and industrialmore » control system. Finally, the main result is a nonintrusive, nondestructive, real-time diagnostic scheme for prediction of bunch profiles, as well as other beam parameters, the precise control of which are important for the plasma wakefield acceleration experiments being explored at FACET.« less

The role of fluctuation-induced transport in a toroidal plasma with strong radial electric fields

NASA Technical Reports Server (NTRS)

Roth, J. R.; Krawczonek, W. M.; Powers, E. J.; Hong, J. Y.; Kim, Y. C.

1981-01-01

Previous work employing digitally implemented spectral analysis techniques is extended to demonstrate that radial fluctuation-induced transport is the dominant ion transport mechanism in an electric field dominated toroidal plasma. Such transport can be made to occur against a density gradient, and hence may have a very beneficial effect on confinement in toroidal plasmas of fusion interest. It is shown that Bohm or classical diffusion down a density gradient, the collisional Pedersen-current mechanism, and the collisionless electric field gradient mechanism described by Cole (1976) all played a minor role, if any, in the radial transport of this plasma.

Genotyping tumour DNA in cerebrospinal fluid and plasma of a HER2-positive breast cancer patient with brain metastases

PubMed Central

Siravegna, Giulia; Geuna, Elena; Mussolin, Benedetta; Crisafulli, Giovanni; Bartolini, Alice; Galizia, Danilo; Casorzo, Laura; Sarotto, Ivana; Scaltriti, Maurizio; Sapino, Anna; Bardelli, Alberto; Montemurro, Filippo

2017-01-01

Background Central nervous system (CNS) involvement contributes to significant morbidity and mortality in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) and represents a major challenge for clinicians. Liquid biopsy of cerebrospinal fluid (CSF)-derived circulating tumour DNA (ctDNA) harbours clinically relevant genomic alterations in patients with CNS metastases and could be effective in tracking tumour evolution. Methods In a HER2-positive mBC patient with brain metastases, we applied droplet digital PCR (ddPCR) and next-generation whole exome sequencing (WES) analysis to measure ctDNA dynamic changes in CSF and plasma collected during treatment. Results Baseline CSF-derived ctDNA analysis revealed TP53 and PIK3CA mutations as well as ERBB2 and cMYC amplification. Post-treatment ctDNA analysis showed decreased markers level in plasma, consistent with extra-CNS disease control, while increased in the CSF, confirming poor treatment benefit in the CNS. Discussion Analysis of ctDNA in the CSF of HER2-positive mBC is feasible and could represent a useful companion for clinical management of brain metastases. PMID:29067216

Application of digital control techniques for satellite medium power DC-DC converters

NASA Astrophysics Data System (ADS)

Skup, Konrad R.; Grudzinski, Pawel; Nowosielski, Witold; Orleanski, Piotr; Wawrzaszek, Roman

2010-09-01

The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter bases on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage mode stabilization that was implemented using VHDL. The described controllers are a classical digital PID controller and a bang-bang controller. The used converter for testing is a simple model of 5-20 W, 200 kHz buck power converter. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.

Design of a digital multiradian phase detector and its application in fusion plasma interferometry.

PubMed

Mlynek, A; Schramm, G; Eixenberger, H; Sips, G; McCormick, K; Zilker, M; Behler, K; Eheberg, J

2010-03-01

We discuss the circuit design of a digital multiradian phase detector that measures the phase difference between two 10 kHz square wave TTL signals and provides the result as a binary number. The phase resolution of the circuit is 1/64 period and its dynamic range is 256 periods. This circuit has been developed for fusion plasma interferometry with submillimeter waves on the ASDEX Upgrade tokamak. The results from interferometric density measurement are discussed and compared to those obtained with the previously used phase detectors, especially with respect to the occurrence of phase jumps. It is illustrated that the new phase measurement provides a powerful tool for automatic real-time validation of the measured density, which is important for feedback algorithms that are sensitive to spurious density signals.

Pioneer Venus Orbiter planar retarding potential analyzer plasma experiment

NASA Technical Reports Server (NTRS)

Knudsen, W. C.; Bakke, J.; Spenner, K.; Novak, V.

1980-01-01

The retarding potential analyzer (RPA) on the Pioneer Venus Orbiter Mission measures most of the thermal plasma parameters within and near the Venusian ionosphere. Parameters include total ion concentration, concentrations of the more abundant ions, ion temperatures, ion drift velocity, electron temperature, and low-energy (0-50 eV) electron distribution function. Several functions not previously used in RPA's were developed and incorporated into this instrument to accomplish these measurements on a spinning spacecraft with a small bit rate. The more significant functions include automatic electrometer ranging with background current compensation; digital, quadratic retarding potential step generation for the ion and low-energy electron scans; a current sampling interval of 2 ms throughout all scans; digital logic inflection point detection and data selection; and automatic ram direction detection.

THOR Field and Wave Processor - FWP

NASA Astrophysics Data System (ADS)

Soucek, Jan; Rothkaehl, Hanna; Balikhin, Michael; Zaslavsky, Arnaud; Nakamura, Rumi; Khotyaintsev, Yuri; Uhlir, Ludek; Lan, Radek; Yearby, Keith; Morawski, Marek; Winkler, Marek

2016-04-01

If selected, Turbulence Heating ObserveR (THOR) will become the first mission ever flown in space dedicated to plasma turbulence. The Fields and Waves Processor (FWP) is an integrated electronics unit for all electromagnetic field measurements performed by THOR. FWP will interface with all fields sensors: electric field antennas of the EFI instrument, the MAG fluxgate magnetometer and search-coil magnetometer (SCM) and perform data digitization and on-board processing. FWP box will house multiple data acquisition sub-units and signal analyzers all sharing a common power supply and data processing unit and thus a single data and power interface to the spacecraft. Integrating all the electromagnetic field measurements in a single unit will improve the consistency of field measurement and accuracy of time synchronization. The feasibility of making highly sensitive electric and magnetic field measurements in space has been demonstrated by Cluster (among other spacecraft) and THOR instrumentation complemented by a thorough electromagnetic cleanliness program will further improve on this heritage. Taking advantage of the capabilities of modern electronics, FWP will provide simultaneous synchronized waveform and spectral data products at high time resolution from the numerous THOR sensors, taking advantage of the large telemetry bandwidth of THOR. FWP will also implement a plasma a resonance sounder and a digital plasma quasi-thermal noise analyzer designed to provide high cadence measurements of plasma density and temperature complementary to data from particle instruments. FWP will be interfaced with the particle instrument data processing unit (PPU) via a dedicated digital link which will enable performing on board correlation between waves and particles, quantifying the transfer of energy between waves and particles. The FWP instrument shall be designed and built by an international consortium of scientific institutes from Czech Republic, Poland, France, UK, Sweden and Austria.

47 CFR 73.9001 - Redistribution control of digital television broadcasts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Redistribution control of digital television... RADIO SERVICES RADIO BROADCAST SERVICES Digital Broadcast Television Redistribution Control § 73.9001 Redistribution control of digital television broadcasts. Licensees of TV broadcast stations may utilize the...

Amplicon-based next-generation sequencing of plasma cell-free DNA for detection of driver and resistance mutations in advanced non-small cell lung cancer.

PubMed

Guibert, N; Hu, Y; Feeney, N; Kuang, Y; Plagnol, V; Jones, G; Howarth, K; Beeler, J F; Paweletz, C P; Oxnard, G R

2018-04-01

Genomic analysis of plasma cell-free DNA is transforming lung cancer care; however, available assays are limited by cost, turnaround time, and imperfect accuracy. Here, we study amplicon-based plasma next-generation sequencing (NGS), rather than hybrid-capture-based plasma NGS, hypothesizing this would allow sensitive detection and monitoring of driver and resistance mutations in advanced non-small cell lung cancer (NSCLC). Plasma samples from patients with NSCLC and a known targetable genotype (EGFR, ALK/ROS1, and other rare genotypes) were collected while on therapy and analyzed blinded to tumor genotype. Plasma NGS was carried out using enhanced tagged amplicon sequencing of hotspots and coding regions from 36 genes, as well as intronic coverage for detection of ALK/ROS1 fusions. Diagnostic accuracy was compared with plasma droplet digital PCR (ddPCR) and tumor genotype. A total of 168 specimens from 46 patients were studied. Matched plasma NGS and ddPCR across 120 variants from 80 samples revealed high concordance of allelic fraction (R2 = 0.95). Pretreatment, sensitivity of plasma NGS for the detection of EGFR driver mutations was 100% (30/30), compared with 87% for ddPCR (26/30). A full spectrum of rare driver oncogenic mutations could be detected including sensitive detection of ALK/ROS1 fusions (8/9 detected, 89%). Studying 25 patients positive for EGFR T790M that developed resistance to osimertinib, 15 resistance mechanisms could be detected including tertiary EGFR mutations (C797S, Q791P) and mutations or amplifications of non-EGFR genes, some of which could be detected pretreatment or months before progression. This blinded analysis demonstrates the ability of amplicon-based plasma NGS to detect a full range of targetable genotypes in NSCLC, including fusion genes, with high accuracy. The ability of plasma NGS to detect a range of preexisting and acquired resistance mechanisms highlights its potential value as an alternative to single mutation digital PCR-based plasma assays for personalizing treatment of TKI resistance in lung cancer.

75 FR 30077 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Digital I&C...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... Subcommittee On Digital I&C Systems The ACRS Subcommittee on Digital Instrumentation and Control (DI&C) Systems... the area of Digital Instrumentation and Control (DI&C) Probabilistic Risk Assessment (PRA). Topics... software reliability methods (QSRMs), NUREG/CR--6997, ``Modeling a Digital Feedwater Control System Using...

Design and implementation of new control room system in Damavand tokamak

NASA Astrophysics Data System (ADS)

Rasouli, H.; Zamanian, H.; Gheidi, M.; Kheiri-Fard, M.; Kouhi, A.

2017-07-01

The aim of this paper is design and implementation of an up-to-date control room. The previous control room had a lot of constraints and it was not apposite to the sophisticated diagnostic systems as well as to the modern control and multivariable systems. Although it provided the best output for the considered experiments and implementing offline algorithms among all similar plants, it needed to be developed to provide more capability for complex algorithm mechanisms and this work introduces our efforts in this area. Accordingly, four leading systems were designed and implemented, including real-time control system, online Data Acquisition System (DAS), offline DAS, monitoring and data transmission system. In the control system, three real-time control modules were established based on Digital Signal Processor (DSP). Thanks to them, implementation of the classic and linear and nonlinear intelligent controllers was possible to control the plasma position and its elongation. Also, online DAS was constructed in two modules. Using them, voltages and currents of charge for the capacitor banks and pressure of different parts in vacuum vessel were measured and monitored. Likewise, by real-time processing of the online data, the safety protocol of plant performance was accomplished. In addition, the offline DAS was organized in 13 modules based on Field Programmable Gate Array (FPGA). This system can be used for gathering all diagnostic, control, and performance data in 156 channels. Data transmission system and storing mechanism in the server was provided by data transmitting network and MDSplus standard protocol. Moreover, monitoring software was designed so that it could display the required plots for physical analyses. Taking everything into account, this new platform can improve the quality and quantity of research activities in plasma physics for Damavand tokamak.

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

Schlossberg, David J.; Bodner, Grant M.; Bongard, Michael W.

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in D.J. Schlossberg et al., 'Non-Inductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta,' Phys. Rev. Lett. 119, 035001 (2017).

Detection of IDH1 mutation in the plasma of patients with glioma.

PubMed

Boisselier, Blandine; Gállego Pérez-Larraya, Jaime; Rossetto, Marta; Labussière, Marianne; Ciccarino, Pietro; Marie, Yannick; Delattre, Jean-Yves; Sanson, Marc

2012-10-16

The IDH1(R132H) mutation is both a strong prognostic predictor and a diagnostic hallmark of gliomas and therefore has major clinical relevance. Here, we developed a new technique to detect the IDH1(R132H) mutation in the plasma of patients with glioma. Small-size DNA (150-250 base pairs) was extracted from the plasma of 31 controls and 80 patients with glioma with known IDH1(R132H) status and correlated with MRI data. The IDH1(R132H) mutation was detected by a combination of coamplification at lower denaturation temperature and digital PCR. The small size DNA concentration was 1.2 ng/mL (range 0.1-6.6) in controls vs 1.2 ng/mL (range 0.1-50.3) in patients with glioma (p = not significant) and 0.9 ng/mL (0.0-3.0) in low-grade gliomas vs 1.5 ng/mL in high-grade gliomas (p < 0.01). The small size DNA concentration correlated with enhancing tumor volume (1.6 ng/mL [0.4-24.9] when <10 cm(3) and 14.0 ng/mL [0.6-50.3] when ≥10 cm(3)). The IDH1(R132H) mutation was detected in 15 out of 25 plasma DNA mixtures (60%) from patients with mutated tumors and in none of the 14 patients with a nonmutated tumor. The sensitivity increased with enhancing tumor volume (3/9 in nonenhancing tumors, 6/10 for enhancing volume <10 cm(3), and 6/6 for enhancing volume ≥10 cm(3)). With a specificity of 100% and a sensitivity related to the tumor volume and contrast enhancement, IDH1(R132H) identification has a valuable diagnostic accuracy in patients not amenable to biopsy.

The fine structure of Langmuir waves observed upstream of the bow shock at Venus

NASA Technical Reports Server (NTRS)

Hospodarsky, G. B.; Gurnett, D. A.; Kurth, W. S.; Kivelson, M. G.; Strangeway, R. J.; Bolton, S. J.

1994-01-01

Highly structured Langmuir waves, also known as electron plasma oscillations, have been observed in the foreshock of Venus using the plasma wave experiment on the Galileo spacecraft during the gravity assist flyby on February 10, 1990. The Galileo wideband sampling system provides digital electric field waveform measurements at sampling rates up to 201,600 samples per second, much higher than any previous instrument of this type. The main Langmuir wave emission band occurs near the local electron plasma frequency, which was approximately 43 kHz. The Langmuir waves are observed to shift above and below the plasma frequency, sometimes by as much as 20 kHz. The shifts in frequency are closely correlated with the downstream distance from the tangent field line, implying that the shifts are controlled by the electron beam velocity. Considerable fine structure is also evident, with time scales as short as 0.15 milliseconds, corresponding to spatial scales of a few tens of Debye lengths. The frequency spectrum often consists of beat-type waveforms, with beat frequencies ranging from 0.2 to 7 kHz, and in a few cases, isolated wavepackets. The peak electric field strengths are approximately 1 mV/m. These field strengths are too small for strongly nonlinear processes to be important. The beat-type waveforms are suggestive of a parametric decay process.

Digital control of the Kuiper Airborne Observatory telescope

NASA Technical Reports Server (NTRS)

Mccormack, Ann C.; Snyder, Philip K.

1989-01-01

The feasibility of using a digital controller to stabilize a telescope mounted in an airplane is investigated. The telescope is a 30 in. infrared telescope mounted aboard a NASA C-141 aircraft known as the Kuiper Airborne Observatory. Current efforts to refurbish the 14-year-old compensation system have led to considering a digital controller. A typical digital controller is modeled and added into the telescope system model. This model is simulated on a computer to generate the Bode plots and time responses which determine system stability and performance parameters. Important aspects of digital control system hardware are discussed. A summary of the findings shows that a digital control system would result in satisfactory telescope performance.

Digital Signal Processing and Control for the Study of Gene Networks

NASA Astrophysics Data System (ADS)

Shin, Yong-Jun

2016-04-01

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

Digital Signal Processing and Control for the Study of Gene Networks.

PubMed

Shin, Yong-Jun

2016-04-22

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

Digital Signal Processing and Control for the Study of Gene Networks

PubMed Central

Shin, Yong-Jun

2016-01-01

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks. PMID:27102828

Apparatus Notes.

ERIC Educational Resources Information Center

Eaton, Bruce G., Ed.

1978-01-01

Describes three pieces of scientific apparatus and their demonstrational use: a high temperature apparatus for positron annihilation studies, a digitally synthesized classroom variable star, and a demonstration of plasma laser-beam focusing using paint stripper flames. (GA)

Resistive wall mode feedback control in EXTRAP T2R with improved steady-state error and transient response

NASA Astrophysics Data System (ADS)

Brunsell, P. R.; Olofsson, K. E. J.; Frassinetti, L.; Drake, J. R.

2007-10-01

Experiments in the EXTRAP T2R reversed field pinch [P. R. Brunsell, H. Bergsåker, M. Cecconello et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] on feedback control of m =1 resistive wall modes (RWMs) are compared with simulations using the cylindrical linear magnetohydrodynamic model, including the dynamics of the active coils and power amplifiers. Stabilization of the main RWMs (n=-11,-10,-9,-8,+5,+6) is shown using modest loop gains of the order G ˜1. However, other marginally unstable RWMs (n=-2,-1,+1,+2) driven by external field errors are only partially canceled at these gains. The experimental system stability limit is confirmed by simulations showing that the latency of the digital controller ˜50μs is degrading the system gain margin. The transient response is improved with a proportional-plus-derivative controller, and steady-state error is improved with a proportional-plus-integral controller. Suppression of all modes is obtained at high gain G ˜10 using a proportional-plus-integral-plus-derivative controller.

Comparison of flight results with digital simulation for a digital electronic engine control in an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.; Burcham, F. W., Jr.

1983-01-01

Substantial benefits of a full authority digital electronic engine control on an air breathing engine were demonstrated repeatedly in simulation studies, ground engine tests, and engine altitude test facilities. A digital engine electronic control system showed improvements in efficiency, performance, and operation. An additional benefit of full authority digital controls is the capability of detecting and correcting failures and providing engine health diagnostics.

Sea-level evaluation of digitally implemented turbojet engine control functions

NASA Technical Reports Server (NTRS)

Arpasi, D. J.; Cwynar, D. S.; Wallhagen, R. E.

1972-01-01

The standard hydromechanical control system of a turbojet engine was replaced with a digital control system that implemented the same control laws. A detailed discussion of the digital control system in use with the engine is presented. The engine was operated in a sea-level test stand. The effects of control update interval are defined, and a method for extending this interval by using digital compensation is discussed.

Army/NASA small turboshaft engine digital controls research program

NASA Technical Reports Server (NTRS)

Sellers, J. F.; Baez, A. N.

1981-01-01

The emphasis of a program to conduct digital controls research for small turboshaft engines is on engine test evaluation of advanced control logic using a flexible microprocessor based digital control system designed specifically for research on advanced control logic. Control software is stored in programmable memory. New control algorithms may be stored in a floppy disk and loaded directly into memory. This feature facilitates comparative evaluation of different advanced control modes. The central processor in the digital control is an Intel 8086 16 bit microprocessor. Control software is programmed in assembly language. Software checkout is accomplished prior to engine test by connecting the digital control to a real time hybrid computer simulation of the engine. The engine currently installed in the facility has a hydromechanical control modified to allow electrohydraulic fuel metering and VG actuation by the digital control. Simulation results are presented which show that the modern control reduces the transient rotor speed droop caused by unanticipated load changes such as cyclic pitch or wind gust transients.

Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control

NASA Technical Reports Server (NTRS)

Baer-Riedhart, Jennifer L.; Landy, Robert J.

1987-01-01

The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

Inward transport of a toroidally confined plasma subject to strong radial electric fields

NASA Technical Reports Server (NTRS)

Roth, J. R.; Krawczonek, W. M.; Powers, E. J.; Hong, J.; Kim, Y.

1977-01-01

The paper aims at showing that the density and confinement time of a toroidal plasma can be enhanced by radial electric fields far stronger than the ambipolar values, and that, if such electric fields point into the plasma, radially inward transport can result. The investigation deals with low-frequency fluctuation-induced transport using digitally implemented spectral analysis techniques and with the role of strong applied radial electric fields and weak vertical magnetic fields on plasma density and particle confinement times in a Bumpy Torus geometry. Results indicate that application of sufficiently strong radially inward electric fields results in radially inward fluctuation-induced transport into the toroidal electrostatic potential well; this inward transport gives rise to higher average electron densities and longer particle confinement times in the toroidal plasma.

Fabrication and test of digital output interface devices for gas turbine electronic controls

NASA Technical Reports Server (NTRS)

Newirth, D. M.; Koenig, E. W.

1978-01-01

A program was conducted to develop an innovative digital output interface device, a digital effector with optical feedback of the fuel metering valve position, for future electronic controls for gas turbine engines. A digital effector (on-off solenoids driven directly by on-off signals from a digital electronic controller) with optical position feedback was fabricated, coupled with the fuel metering valve, and tested under simulated engine operating conditions. The testing indicated that a digital effector with optical position feedback is a suitable candidate, with proper development for future digital electronic gas turbine controls. The testing also identified several problem areas which would have to be overcome in a final production configuration.

Could Digital PCR Be an Alternative as a Non-Invasive Prenatal Test for Trisomy 21: A Proof of Concept Study

PubMed Central

El Khattabi, Laïla Allach; Rouillac-Le Sciellour, Christelle; Le Tessier, Dominique; Luscan, Armelle; Coustier, Audrey; Porcher, Raphael; Bhouri, Rakia; Nectoux, Juliette; Sérazin, Valérie; Quibel, Thibaut; Mandelbrot, Laurent; Tsatsaris, Vassilis

2016-01-01

Objective NIPT for fetal aneuploidy by digital PCR has been hampered by the large number of PCR reactions needed to meet statistical requirements, preventing clinical application. Here, we designed an octoplex droplet digital PCR (ddPCR) assay which allows increasing the number of available targets and thus overcomes statistical obstacles. Method After technical optimization of the multiplex PCR on mixtures of trisomic and euploid DNA, we performed a validation study on samples of plasma DNA from 213 pregnant women. Molecular counting of circulating cell-free DNA was performed using a mix of hydrolysis probes targeting chromosome 21 and a reference chromosome. Results The results of our validation experiments showed that ddPCR detected trisomy 21 even when the sample’s trisomic DNA content is as low as 5%. In a validation study of plasma samples from 213 pregnant women, ddPCR discriminated clearly between the trisomy 21 and the euploidy groups. Conclusion Our results demonstrate that digital PCR can meet the requirements for non-invasive prenatal testing of trisomy 21. This approach is technically simple, relatively cheap, easy to implement in a diagnostic setting and compatible with ethical concerns regarding access to nucleotide sequence information. These advantages make it a potential technique of choice for population-wide screening for trisomy 21 in pregnant women. PMID:27167625

47 CFR 76.1909 - Redistribution control of unencrypted digital terrestrial broadcast content.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Redistribution control of unencrypted digital... Redistribution control of unencrypted digital terrestrial broadcast content. (a) For the purposes of this section, the terms unencrypted digital terrestrial broadcast content, EIT, PMT, broadcast flag, covered...

High-power microwave-induced TM{sub 01} plasma ring

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

Schamiloglu, E.; Jordan, R.; Moreland, L.D.

1996-02-01

Open-shutter photography was used to capture the air breakdown pattern induced by a TM{sub 01} mode radiated by a high-power backward wave oscillator. The resultant plasma ring was formed in air adjacent to a conical horn antenna fitted with a membrane to keep the experiment under vacuum. This image was digitized and further processed using Khoros 2.0 software to obtain the dimensions of the plasma ring. This information was used in an air breakdown analysis to estimate the radiated power, and agrees within 10% with the power measured using field mapping with an open-ended WR-90 waveguide.

Impaired psychomotor function and plasma methadone and levo-alpha-acetylmethadol (LAAM) concentrations in opioid-substitution patients.

PubMed

Newcombe, David A L; Somogyi, Andrew A; Bochner, Felix; White, Jason M

2017-06-01

Tolerance to the psychomotor impairing effects of opioid drugs is expected to develop with repeated dosing, but may be incomplete. The relationship between plasma opioid concentration and psychomotor function in opioid-dependent patients was examined to determine whether impairment was more likely at the time of highest plasma drug concentration. Sixteen patients participating in a cross-over trial comparing methadone and LAAM completed a tracking task (OSPAT) 11 times over the dosing-interval for methadone (24-hrs) and LAAM (48-hrs). Venous blood was collected for the quantification of plasma (R)-(-)-methadone, LAAM, and nor-LAAM concentrations. The Digit Symbol Substitution Test (DSST) and Trail-Making Test were administered at the time of peak plasma concentration. Ten healthy controls (HCs) also participated. OSPAT scores (obtained for 15 patients) fluctuated significantly across the dosing-interval for both drugs and were lower in patients than HCs at the times of peak concentrations of (R)-(-)-methadone (1 hr: (mean difference; 95% CI) (2.13; 0.18-4.08); 2 hrs: (2.38; 0.48-4.28) postdosing) and LAAM (2 hrs: (1.81; 0.09-3.53), and 4 hrs (1.90: 0.9-3.71) postdosing). Within-participant analysis of the peak-change from baseline for OSPAT scores found that 10 of the 15 patients could be categorized as impaired on methadone and 9 on LAAM. No HCs were impaired. Patients performed worse on the DSST and Trails-A than HCs, but not on Trails-B. Results suggest that some patients receiving opioids long term may exhibit impairment at the time of highest plasma drug concentration. These patients should be made aware that their ability to undertake complex tasks may be affected. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

High-fat meals rich in EPA plus DHA compared with DHA only have differential effects on postprandial lipemia and plasma 8-isoprostane F2α concentrations relative to a control high–oleic acid meal: a randomized controlled trial1234

PubMed Central

Purcell, Robert; Latham, Sally H; Botham, Kathleen M; Hall, Wendy L; Wheeler-Jones, Caroline PD

2014-01-01

Background: Eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplementation has beneficial cardiovascular effects, but postprandial influences of these individual fatty acids are unclear. Objectives: The primary objective was to determine the vascular effects of EPA + DHA compared with DHA only during postprandial lipemia relative to control high–oleic acid meals; the secondary objective was to characterize the effects of linoleic acid–enriched high-fat meals relative to the control meal. Design: We conducted a randomized, controlled, double-blind crossover trial of 4 high-fat (75-g) meals containing 1) high–oleic acid sunflower oil (HOS; control), 2) HOS + fish oil (FO; 5 g EPA and DHA), 3) HOS + algal oil (AO; 5 g DHA), and 4) high–linoleic acid sunflower oil (HLS) in 16 healthy men (aged 35–70 y) with higher than optimal fasting triacylglycerol concentrations (mean ± SD triacylglycerol, 1.9 ± 0.5 mmol/L). Results: Elevations in triacylglycerol concentration relative to baseline were slightly reduced after FO and HLS compared with the HOS control (P < 0.05). The characteristic decrease from baseline in plasma nonesterified fatty acids after a mixed meal was inhibited after AO (Δ 0–3 h, P < 0.05). HLS increased the augmentation index compared with the other test meals (P < 0.05), although the digital volume pulse–reflection index was not significantly different. Plasma 8-isoprostane F2α analysis revealed opposing effects of FO (increased) and AO (reduced) compared with the control (P < 0.05). No differences in nitric oxide metabolites were observed. Conclusions: These data show differential postprandial 8-isoprostane F2α responses to high-fat meals containing EPA + DHA–rich fish oil compared with DHA-rich AO, but these differences were not associated with consistent effects on postprandial vascular function or lipemia. More detailed analyses of polyunsaturated fatty acid–derived lipid mediators are required to determine possible divergent functional effects of single meals rich in either DHA or EPA. This trial was registered at clinicaltrials.gov as NCT01618071. PMID:25099540

High-fat meals rich in EPA plus DHA compared with DHA only have differential effects on postprandial lipemia and plasma 8-isoprostane F2α concentrations relative to a control high-oleic acid meal: a randomized controlled trial.

PubMed

Purcell, Robert; Latham, Sally H; Botham, Kathleen M; Hall, Wendy L; Wheeler-Jones, Caroline P D

2014-10-01

Eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplementation has beneficial cardiovascular effects, but postprandial influences of these individual fatty acids are unclear. The primary objective was to determine the vascular effects of EPA + DHA compared with DHA only during postprandial lipemia relative to control high-oleic acid meals; the secondary objective was to characterize the effects of linoleic acid-enriched high-fat meals relative to the control meal. We conducted a randomized, controlled, double-blind crossover trial of 4 high-fat (75-g) meals containing 1) high-oleic acid sunflower oil (HOS; control), 2) HOS + fish oil (FO; 5 g EPA and DHA), 3) HOS + algal oil (AO; 5 g DHA), and 4) high-linoleic acid sunflower oil (HLS) in 16 healthy men (aged 35-70 y) with higher than optimal fasting triacylglycerol concentrations (mean ± SD triacylglycerol, 1.9 ± 0.5 mmol/L). Elevations in triacylglycerol concentration relative to baseline were slightly reduced after FO and HLS compared with the HOS control (P < 0.05). The characteristic decrease from baseline in plasma nonesterified fatty acids after a mixed meal was inhibited after AO (Δ 0-3 h, P < 0.05). HLS increased the augmentation index compared with the other test meals (P < 0.05), although the digital volume pulse-reflection index was not significantly different. Plasma 8-isoprostane F2α analysis revealed opposing effects of FO (increased) and AO (reduced) compared with the control (P < 0.05). No differences in nitric oxide metabolites were observed. These data show differential postprandial 8-isoprostane F2α responses to high-fat meals containing EPA + DHA-rich fish oil compared with DHA-rich AO, but these differences were not associated with consistent effects on postprandial vascular function or lipemia. More detailed analyses of polyunsaturated fatty acid-derived lipid mediators are required to determine possible divergent functional effects of single meals rich in either DHA or EPA. This trial was registered at clinicaltrials.gov as NCT01618071.

Demonstration of Standard HVAC Single-Loop Digital Control Systems

DTIC Science & Technology

1993-01-01

AD-A265 372 T N FEAP-TR-FE-93/05 REPORT January 1993 FACILITIES ENGINEERING APPLICATIONS PROGRAM Demonstration of Standard HVAC Single-Loop Digital...AND DATES COVERED January 1993 Final 4. TITLE AND SUBTITLE [5. FUNDING NUMBERS Demonstration of Standard HVAC Single-Loop Digital Control Systems FEAP...conditioning ( HVAC ) control systems provide guidance on designing and specifying standard HVAC control systems that use single-loop digital controllers

Digital flight control research

NASA Technical Reports Server (NTRS)

Potter, J. E.; Stern, R. G.; Smith, T. B.; Sinha, P.

1974-01-01

The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator.

Digital-computer normal shock position and restart control of a Mach 2.5 axisymmetric mixed-compression inlet

NASA Technical Reports Server (NTRS)

Neiner, G. H.; Cole, G. L.; Arpasi, D. J.

1972-01-01

Digital computer control of a mixed-compression inlet is discussed. The inlet was terminated with a choked orifice at the compressor face station to dynamically simulate a turbojet engine. Inlet diffuser exit airflow disturbances were used. A digital version of a previously tested analog control system was used for both normal shock and restart control. Digital computer algorithms were derived using z-transform and finite difference methods. Using a sample rate of 1000 samples per second, the digital normal shock and restart controls essentially duplicated the inlet analog computer control results. At a sample rate of 100 samples per second, the control system performed adequately but was less stable.

Digital ELISA for the quantification of attomolar concentrations of Alzheimer's disease biomarker protein Tau in biological samples.

PubMed

Pérez-Ruiz, Elena; Decrop, Deborah; Ven, Karen; Tripodi, Lisa; Leirs, Karen; Rosseels, Joelle; van de Wouwer, Marlies; Geukens, Nick; De Vos, Ann; Vanmechelen, Eugeen; Winderickx, Joris; Lammertyn, Jeroen; Spasic, Dragana

2018-07-26

The close correlation between Tau pathology and Alzheimer's disease (AD) progression makes this protein a suitable biomarker for diagnosis and monitoring of the disorder evolution. However, the use of Tau in diagnostics has been hampered, as it currently requires collection of cerebrospinal fluid (CSF), which is an invasive clinical procedure. Although measuring Tau-levels in blood plasma would be favorable, the concentrations are below the detection limit of a conventional ELISA. In this work, we developed a digital ELISA for the quantification of attomolar protein Tau concentrations in both buffer and biological samples. Individual Tau molecules were first captured on the surface of magnetic particles using in-house developed antibodies and subsequently isolated into the femtoliter-sized wells of a 2 × 2 mm 2 microwell array. Combination of high-affinity antibodies, optimal assay conditions and a digital quantification approach resulted in a 24 ± 7 aM limit of detection (LOD) in buffer samples. Additionally, a dynamic range of 6 orders of magnitude was achieved by combining the digital readout with an analogue approach, allowing quantification from attomolar to picomolar levels of Tau using the same platform. This proves the compatibility of the presented assay with the wide range of Tau concentrations encountered in different biological samples. Next, the developed digital assay was applied to detect total Tau levels in spiked blood plasma. A similar LOD (55 ± 29 aM) was obtained compared to the buffer samples, which was 5000-fold more sensitive than commercially available ELISAs and even outperformed previously reported digital assays with 10-fold increase in sensitivity. Finally, the performance of the developed digital ELISA was assessed by quantifying protein Tau in three clinical CSF samples. Here, a high correlation (i.e. Pearson coefficient of 0.99) was found between the measured percentage of active particles and the reference protein Tau values. The presented digital ELISA technology has great capacity in unlocking the potential of Tau as biomarker for early AD diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

Digital control analysis and design of a field-sensed magnetic suspension system.

PubMed

Li, Jen-Hsing; Chiou, Juing-Shian

2015-03-13

Magnetic suspension systems are mechatronic systems and crucial in several engineering applications, such as the levitation of high-speed trains, frictionless bearings, and wind tunnels. Magnetic suspension systems are nonlinear and unstable systems; therefore, they are suitable educational benchmarks for testing various modeling and control methods. This paper presents the digital modeling and control of magnetic suspension systems. First, the magnetic suspension system is stabilized using a digital proportional-derivative controller. Subsequently, the digital model is identified using recursive algorithms. Finally, a digital mixed linear quadratic regulator (LQR)/H∞ control is adopted to stabilize the magnetic suspension system robustly. Simulation examples and a real-world example are provided to demonstrate the practicality of the study results. In this study, a digital magnetic suspension system model was developed and reviewed. In addition, equivalent state and output feedback controls for magnetic suspension systems were developed. Using this method, the controller design for magnetic suspension systems was simplified, which is the novel contribution of this study. In addition, this paper proposes a complete digital controller design procedure for magnetic suspension systems.

Self-powered integrated microfluidic point-of-care low-cost enabling (SIMPLE) chip

PubMed Central

Yeh, Erh-Chia; Fu, Chi-Cheng; Hu, Lucy; Thakur, Rohan; Feng, Jeffrey; Lee, Luke P.

2017-01-01

Portable, low-cost, and quantitative nucleic acid detection is desirable for point-of-care diagnostics; however, current polymerase chain reaction testing often requires time-consuming multiple steps and costly equipment. We report an integrated microfluidic diagnostic device capable of on-site quantitative nucleic acid detection directly from the blood without separate sample preparation steps. First, we prepatterned the amplification initiator [magnesium acetate (MgOAc)] on the chip to enable digital nucleic acid amplification. Second, a simplified sample preparation step is demonstrated, where the plasma is separated autonomously into 224 microwells (100 nl per well) without any hemolysis. Furthermore, self-powered microfluidic pumping without any external pumps, controllers, or power sources is accomplished by an integrated vacuum battery on the chip. This simple chip allows rapid quantitative digital nucleic acid detection directly from human blood samples (10 to 105 copies of methicillin-resistant Staphylococcus aureus DNA per microliter, ~30 min, via isothermal recombinase polymerase amplification). These autonomous, portable, lab-on-chip technologies provide promising foundations for future low-cost molecular diagnostic assays. PMID:28345028

Using droplet digital PCR to analyze MYCN and ALK copy number in plasma from patients with neuroblastoma.

PubMed

Lodrini, Marco; Sprüssel, Annika; Astrahantseff, Kathy; Tiburtius, Daniela; Konschak, Robert; Lode, Holger N; Fischer, Matthias; Keilholz, Ulrich; Eggert, Angelika; Deubzer, Hedwig E

2017-10-17

The invasive nature of surgical biopsies deters sequential application, and single biopsies often fail to reflect tumor dynamics, intratumor heterogeneity and drug sensitivities likely to change during tumor evolution and treatment. Implementing molecular characterization of cell-free neuroblastoma-derived DNA isolated from blood plasma could improve disease assessment for treatment selection and monitoring of patients with high-risk neuroblastoma. We established droplet digital PCR (ddPCR) protocols for MYCN and ALK copy number status in plasma from neuroblastoma patients. Our ddPCR protocol accurately discriminated between MYCN and ALK amplification, gain and normal diploid status in a large panel of neuroblastoma cell lines, and discrepancies with reported MYCN and ALK status were detected, including a high-level MYCN amplification in NB-1, a MYCN gain in SH-SY5Y, a high-level ALK amplification in IMR-32 and ALK gains in BE(2)-C, Kelly, SH-SY5Y and LAN-6. MYCN and ALK status were also reliably determined from cell-free DNA derived from medium conditioned by the cell lines. MYCN and ALK copy numbers of subcutaneous neuroblastoma xenograft tumors were accurately determined from cell-free DNA in the mouse blood plasma. In a final validation step, we accurately distinguished MYCN and ALK copy numbers of the corresponding primary tumors using retrospectively collected blood plasma samples from 10 neuroblastoma patients. Our data justify the further development of molecular disease characterization using cell-free DNA in blood plasma from patients with neuroblastoma. This expanded molecular diagnostic palette may improve monitoring of disease progression including relapse and metastatic events as well as therapy success or failure in high-risk neuroblastoma patients.

Using droplet digital PCR to analyze MYCN and ALK copy number in plasma from patients with neuroblastoma

PubMed Central

Lodrini, Marco; Sprüssel, Annika; Astrahantseff, Kathy; Tiburtius, Daniela; Konschak, Robert; Lode, Holger N.; Fischer, Matthias; Keilholz, Ulrich; Eggert, Angelika; Deubzer, Hedwig E.

2017-01-01

The invasive nature of surgical biopsies deters sequential application, and single biopsies often fail to reflect tumor dynamics, intratumor heterogeneity and drug sensitivities likely to change during tumor evolution and treatment. Implementing molecular characterization of cell-free neuroblastoma-derived DNA isolated from blood plasma could improve disease assessment for treatment selection and monitoring of patients with high-risk neuroblastoma. We established droplet digital PCR (ddPCR) protocols for MYCN and ALK copy number status in plasma from neuroblastoma patients. Our ddPCR protocol accurately discriminated between MYCN and ALK amplification, gain and normal diploid status in a large panel of neuroblastoma cell lines, and discrepancies with reported MYCN and ALK status were detected, including a high-level MYCN amplification in NB-1, a MYCN gain in SH-SY5Y, a high-level ALK amplification in IMR-32 and ALK gains in BE(2)-C, Kelly, SH-SY5Y and LAN-6. MYCN and ALK status were also reliably determined from cell-free DNA derived from medium conditioned by the cell lines. MYCN and ALK copy numbers of subcutaneous neuroblastoma xenograft tumors were accurately determined from cell-free DNA in the mouse blood plasma. In a final validation step, we accurately distinguished MYCN and ALK copy numbers of the corresponding primary tumors using retrospectively collected blood plasma samples from 10 neuroblastoma patients. Our data justify the further development of molecular disease characterization using cell-free DNA in blood plasma from patients with neuroblastoma. This expanded molecular diagnostic palette may improve monitoring of disease progression including relapse and metastatic events as well as therapy success or failure in high-risk neuroblastoma patients. PMID:29156716

Multiplex picodroplet digital PCR to detect KRAS mutations in circulating DNA from the plasma of colorectal cancer patients.

PubMed

Taly, Valerie; Pekin, Deniz; Benhaim, Leonor; Kotsopoulos, Steve K; Le Corre, Delphine; Li, Xinyu; Atochin, Ivan; Link, Darren R; Griffiths, Andrew D; Pallier, Karine; Blons, Hélène; Bouché, Olivier; Landi, Bruno; Hutchison, J Brian; Laurent-Puig, Pierre

2013-12-01

Multiplex digital PCR (dPCR) enables noninvasive and sensitive detection of circulating tumor DNA with performance unachievable by current molecular-detection approaches. Furthermore, picodroplet dPCR facilitates simultaneous screening for multiple mutations from the same sample. We investigated the utility of multiplex dPCR to screen for the 7 most common mutations in codons 12 and 13 of the KRAS (Kirsten rat sarcoma viral oncogene homolog) oncogene from plasma samples of patients with metastatic colorectal cancer. Fifty plasma samples were tested from patients for whom the primary tumor biopsy tissue DNA had been characterized by quantitative PCR. Tumor characterization revealed that 19 patient tumors had KRAS mutations. Multiplex dPCR analysis of the plasma DNA prepared from these samples identified 14 samples that matched the mutation identified in the tumor, 1 sample contained a different KRAS mutation, and 4 samples had no detectable mutation. Among the tumor samples that were wild type for KRAS, 2 KRAS mutations were identified in the corresponding plasma samples. Duplex dPCR (i.e., wild-type and single-mutation assay) was also used to analyze plasma samples from patients with KRAS-mutated tumors and 5 samples expected to contain the BRAF (v-raf murine sarcoma viral oncogene homolog B) V600E mutation. The results for the duplex analysis matched those for the multiplex analysis for KRAS-mutated samples and, owing to its higher sensitivity, enabled detection of 2 additional samples with low levels of KRAS-mutated DNA. All 5 samples with BRAF mutations were detected. This work demonstrates the clinical utility of multiplex dPCR to screen for multiple mutations simultaneously with a sensitivity sufficient to detect mutations in circulating DNA obtained by noninvasive blood collection.

Scale-up of a physiologically-based pharmacokinetic model to predict the disposition of monoclonal antibodies in monkeys.

PubMed

Glassman, Patrick M; Chen, Yang; Balthasar, Joseph P

2015-10-01

Preclinical assessment of monoclonal antibody (mAb) disposition during drug development often includes investigations in non-human primate models. In many cases, mAb exhibit non-linear disposition that relates to mAb-target binding [i.e., target-mediated disposition (TMD)]. The goal of this work was to develop a physiologically-based pharmacokinetic (PBPK) model to predict non-linear mAb disposition in plasma and in tissues in monkeys. Physiological parameters for monkeys were collected from several sources, and plasma data for several mAbs associated with linear pharmacokinetics were digitized from prior literature reports. The digitized data displayed great variability; therefore, parameters describing inter-antibody variability in the rates of pinocytosis and convection were estimated. For prediction of the disposition of individual antibodies, we incorporated tissue concentrations of target proteins, where concentrations were estimated based on categorical immunohistochemistry scores, and with assumed localization of target within the interstitial space of each organ. Kinetics of target-mAb binding and target turnover, in the presence or absence of mAb, were implemented. The model was then employed to predict concentration versus time data, via Monte Carlo simulation, for two mAb that have been shown to exhibit TMD (2F8 and tocilizumab). Model predictions, performed a priori with no parameter fitting, were found to provide good prediction of dose-dependencies in plasma clearance, the areas under plasma concentration versu time curves, and the time-course of plasma concentration data. This PBPK model may find utility in predicting plasma and tissue concentration versus time data and, potentially, the time-course of receptor occupancy (i.e., mAb-target binding) to support the design and interpretation of preclinical pharmacokinetic-pharmacodynamic investigations in non-human primates.

Computer aided design of digital controller for radial active magnetic bearings

NASA Technical Reports Server (NTRS)

Cai, Zhong; Shen, Zupei; Zhang, Zuming; Zhao, Hongbin

1992-01-01

A five degree of freedom Active Magnetic Bearing (AMB) system is developed which is controlled by digital controllers. The model of the radial AMB system is linearized and the state equation is derived. Based on the state variables feedback theory, digital controllers are designed. The performance of the controllers are evaluated according to experimental results. The Computer Aided Design (CAD) method is used to design controllers for magnetic bearings. The controllers are implemented with a digital signal processing (DSP) system. The control algorithms are realized with real-time programs. It is very easy to change the controller by changing or modifying the programs. In order to identify the dynamic parameters of the controlled magnetic system, a special experiment was carried out. Also, the online Recursive Least Squares (RLS) parameter identification method is studied. It can be realized with the digital controllers. Online parameter identification is essential for the realization of an adaptive controller.

Plasma enhanced ultrastable self-powered visible-blind deep ultraviolet photodetector based on atomically thin boron nitride sheets

NASA Astrophysics Data System (ADS)

Feng, Peter Xianping; Rivera, Manuel; Velazquez, Rafael; Aldalbahi, Ali

We extend our work on the use of digitally controlled plasma deposition technique to synthesize high quality boron nitride nanosheets (BNNSs). The nanoscale morphologies and layered growth characteristics of the BNNSs were characterized using scanning electron microscope, transmission electron microscopy, and atomic force microscopy. The experimental data indicated each sample consists of multiple atomically thin, highly transparent BNNSs that overlap one another with certain orientations. Purity and structural properties were characterized by Raman scattering, XRD, FTIR and XPS. Based on these characterizations, 2D BNNSs based self-powered, visible blind deep UV detectors were designed, fabricated, and tested. The bias, temperature, and humidity effects on the photocurrent strength were investigated. A significant increase of signal-to-noise ratio after plasma treatment was observed. The fabricated photodetectors presented exceptional properties: a very stable baseline and a high sensitivity to weak intensities of radiation in both UVC and UVB range while remaining visible-blind, a high signal-to-noise ratio, and excellent repeatability even when the operating temperature was up to 400 0C. The shift in cutoff wavelength was also observed. This work is supported by the Army Research Office/DoD Grant (62826-RT-REP) and the ISPP#0058 at King Saud University.

A microwave interferometer for small and tenuous plasma density measurements.

PubMed

Tudisco, O; Lucca Fabris, A; Falcetta, C; Accatino, L; De Angelis, R; Manente, M; Ferri, F; Florean, M; Neri, C; Mazzotta, C; Pavarin, D; Pollastrone, F; Rocchi, G; Selmo, A; Tasinato, L; Trezzolani, F; Tuccillo, A A

2013-03-01

The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10(16) m(-3) and 10(19) m(-3)) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small (λ = 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02° has been used, corresponding to a density of 0.5 × 10(16) m(-3).

Development and testing of controller performance evaluation methodology for multi-input/multi-output digital control systems

NASA Technical Reports Server (NTRS)

Pototzky, Anthony; Wieseman, Carol; Hoadley, Sherwood Tiffany; Mukhopadhyay, Vivek

1991-01-01

Described here is the development and implementation of on-line, near real time controller performance evaluation (CPE) methods capability. Briefly discussed are the structure of data flow, the signal processing methods used to process the data, and the software developed to generate the transfer functions. This methodology is generic in nature and can be used in any type of multi-input/multi-output (MIMO) digital controller application, including digital flight control systems, digitally controlled spacecraft structures, and actively controlled wind tunnel models. Results of applying the CPE methodology to evaluate (in near real time) MIMO digital flutter suppression systems being tested on the Rockwell Active Flexible Wing (AFW) wind tunnel model are presented to demonstrate the CPE capability.

Retarding potential analyzer for the Pioneer-Venus Orbiter Mission

NASA Technical Reports Server (NTRS)

Knudsen, W. C.; Bakke, J.; Spenner, K.; Novak, V.

1979-01-01

The retarding potential analyzer on the Pioneer-Venus Orbiter Mission has been designed to measure most of the thermal plasma parameters within and near the Venusian ionosphere. Parameters include total ion concentration, concentrations of the more abundant ions, ion temperatures, ion drift velocity, electron temperature, and low-energy (0-50 eV) electron distribution function. To accomplish these measurements on a spinning vehicle with a small telemetry bit rate, several functions, including decision functions not previously used in RPA's, have been developed and incorporated into this instrument. The more significant functions include automatic electrometer ranging with background current compensation; digital, quadratic retarding potential step generation for the ion and low-energy electron scans; a current sampling interval of 2 ms throughout all scans; digital logic inflection point detection and data selection; and automatic ram direction detection. Extensive numerical simulation and plasma chamber tests have been conducted to verify adequacy of the design for the Pioneer Mission.

Emergency Flight Control Using Computer-Controlled Thrust

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Fullerton, C. Gordon; Stewart, James F.; Gilyard, Glenn B.; Conley, Joseph A.

1995-01-01

Propulsion Controlled Aircraft (PCA) systems are digital electronic control systems undergoing development to provide limited maneuvering ability through variations of individual engine thrusts in multiple-engine airplanes. Provide landing capability when control surfaces inoperable. Incorporated on existing and future airplanes that include digital engine controls, digital flight controls, and digital data buses, adding no weight for additional hardware to airplane. Possible to handle total failure of hydraulic system, depending on how surfaces respond to loss of hydraulic pressure, and broken control cables or linkages. Future airplanes incorporate data from Global Positioning System for guidance to any suitable emergency runway in world.

Publisher's Announcement

NASA Astrophysics Data System (ADS)

McGlashan, Yasmin

2008-01-01

Important changes for 2008 As a result of reviewing several aspects of our content, both in print and online, we have made some changes for 2008. These changes are described below: Article numbering Plasma Physics and Controlled Fusion has moved from sequential page numbering to an article numbering system, offering important advantages and flexibility by speeding up the publication process. Papers in different issues or sections can be published online as soon as they are ready, without having to wait for a whole issue or section to be allocated page numbers. The bibliographic citation will change slightly. Articles should be referenced using the six-digit article number in place of a page number, and this number must include any leading zeros. For instance, from this issue: Z Y Chen et al 2008 Plasma Phys. Control. Fusion 50 015001 Articles will continue to be published on the web in advance of the print edition. A new look and feel We have also taken the opportunity to refresh the design of the journal cover, in order to modernise the typography and create a consistent look and feel across our range of publications. We hope you like the new cover. If you have any questions or comments about any of these changes, please contact us at ppcf@iop.org.

Self-Expandable Nitinol Stent Placement in Homocysteinemic Porcine Aorta

PubMed Central

França, Luís Henrique Gil; Pereira, Adamastor Humberto; Perini, Sílvio César

2008-01-01

PURPOSE To compare aortic intimal thickening of normal and hyperhomocysteinemic pigs (induced with a methionine-rich diet) following placement of a self-expanding nitinol stent. METHODS Eighteen Macau pigs were used. They were older than eight weeks in age and had an average weight of 30 kg. Pigs were randomly divided into two groups. The first, Group C (control), was fed a regular diet, and the second group, Group M, was fed a methionine-rich diet for 30 days to induce hyperhomocysteinemia. The self-expandable nitinol stents were 25mm in length and 8 mm in diameter after expansion. Blood samples were collected to measure total cholesterol, triglycerides, HDL and homocysteine concentrations. All animals were subjected to angiography. Thirty days after the procedure, the animals were sacrificed, and the abdominal aorta was removed for histological and digital morphometry analysis. RESULTS Under microscopic evaluation, the intima was significantly thicker in Group C than in Group M. When groups were compared by digital morphometric analysis, intimal thickening of the vessel wall was higher in Group C than in Group M. There was no significant change in total cholesterol, triglycerides or HDL concentrations in either group. In group C the levels of plasma homocysteine ranged from 14,40 to 16,73μmol/l; in Group M, plasma homocysteine levels ranged from 17.47 to 59.80 μmol/l after 30 days of a methionine-rich diet. CONCLUSION Compared to normal pigs, less intimal hyperplasia was observed in the abdominal aortas of hyperhomocysteinemic pigs thirty days after the insertion of a self-expandable nitinol stent. PMID:18438578

Medical devices; radiology devices; reclassification of full-field digital mammography system. Final rule.

PubMed

2010-11-05

The Food and Drug Administration (FDA) is announcing the reclassification of the full-field digital mammography (FFDM) system from class III (premarket approval) to class II (special controls). The device type is intended to produce planar digital x-ray images of the entire breast; this generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component parts, and accessories. The special control that will apply to the device is the guidance document entitled "Class II Special Controls Guidance Document: Full-Field Digital Mammography System." FDA is reclassifying the device into class II (special controls) because general controls along with special controls will provide a reasonable assurance of safety and effectiveness of the device. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for this device.

Implementation of Adaptive Digital Controllers on Programmable Logic Devices

NASA Technical Reports Server (NTRS)

Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Monenegro, Justino (Technical Monitor)

2002-01-01

Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used proportional-integral-derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM-based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a DSP (Digital Signal Processor) or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSP) devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. An alternative is required for compact implementation of such functionality to withstand the harsh environment encountered on spacecraft. Radiation tolerant FPGA's are a feasible option for reaching this goal.

Digital PI-PD controller design for arbitrary order systems: Dominant pole placement approach.

PubMed

Dincel, Emre; Söylemez, Mehmet Turan

2018-05-02

In this paper, a digital PI-PD controller design method is proposed for arbitrary order systems with or without time-delay to achieve desired transient response in the closed-loop via dominant pole placement approach. The digital PI-PD controller design problem is solved by converting the original problem to the digital PID controller design problem. Firstly, parametrization of the digital PID controllers which assign dominant poles to desired location is done. After that the subset of digital PID controller parameters in which the remaining poles are located away from the dominant pole pair is found via Chebyshev polynomials. The obtained PID controller parameters are then transformed into the PI-PD controller parameters by considering the closed-loop controller zero and the design is completed. Success of the proposed design method is firstly demonstrated on an example transfer function and compared with the well-known PID controller methods from the literature through simulations. After that the design method is implemented on the fan and plate laboratory system in a real environment. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Digital PCR analysis of circulating nucleic acids.

PubMed

Hudecova, Irena

2015-10-01

Detection of plasma circulating nucleic acids (CNAs) requires the use of extremely sensitive and precise methods. The commonly used quantitative real-time polymerase chain reaction (PCR) poses certain technical limitations in relation to the precise measurement of CNAs whereas the costs of massively parallel sequencing are still relatively high. Digital PCR (dPCR) now represents an affordable and powerful single molecule counting strategy to detect minute amounts of genetic material with performance surpassing many quantitative methods. Microfluidic (chip) and emulsion (droplet)-based technologies have already been integrated into platforms offering hundreds to millions of nanoliter- or even picoliter-scale reaction partitions. The compelling observations reported in the field of cancer research, prenatal testing, transplantation medicine and virology support translation of this technology into routine use. Extremely sensitive plasma detection of rare mutations originating from tumor or placental cells among a large background of homologous sequences facilitates unraveling of the early stages of cancer or the detection of fetal mutations. Digital measurement of quantitative changes in plasma CNAs associated with cancer or graft rejection provides valuable information on the monitoring of disease burden or the recipient's immune response and subsequent therapy treatment. Furthermore, careful quantitative assessment of the viral load offers great value for effective monitoring of antiviral therapy for immunosuppressed or transplant patients. The present review describes the inherent features of dPCR that make it exceptionally robust in precise and sensitive quantification of CNAs. Moreover, I provide an insight into the types of potential clinical applications that have been developed by researchers to date. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Adaptive method for electron bunch profile prediction

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

Scheinker, Alexander; Gessner, Spencer

2015-10-01

We report on an experiment performed at the Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC National Accelerator Laboratory, in which a new adaptive control algorithm, one with known, bounded update rates, despite operating on analytically unknown cost functions, was utilized in order to provide quasi-real-time bunch property estimates of the electron beam. Multiple parameters, such as arbitrary rf phase settings and other time-varying accelerator properties, were simultaneously tuned in order to match a simulated bunch energy spectrum with a measured energy spectrum. The simple adaptive scheme was digitally implemented using matlab and the experimental physics and industrial controlmore » system. The main result is a nonintrusive, nondestructive, real-time diagnostic scheme for prediction of bunch profiles, as well as other beam parameters, the precise control of which are important for the plasma wakefield acceleration experiments being explored at FACET. © 2015 authors. Published by the American Physical Society.« less

Fluctuation spectra in the NASA Lewis bumpy-torus plasma

NASA Technical Reports Server (NTRS)

Singh, C. M.; Krawczonek, W. M.; Roth, J. R.; Hong, J. Y.; Powers, E. J.

1978-01-01

The electrostatic potential fluctuation spectrum in the NASA Lewis bumpy-torus plasma was studied with capacitive probes in the low pressure (high impedance) mode and in the high pressure (low impedance) mode. Under different operating conditions, the plasma exhibited electrostatic potential fluctuations (1) at a set of discrete frequencies, (2) at a continuum of frequencies, and (3) as incoherent high-frequency turbulence. The frequencies and azimuthal wave numbers were determined from digitally implemented autopower and cross-power spectra. The azimuthal dispersion characteristics of the unstable waves were examined by varying the electrode voltage, the polarity of the voltage, and the neutral background density at a constant magnetic field strength.

Association of mutant EGFR L858R and exon 19 concentration in circulating cell-free DNA using droplet digital PCR with response to EGFR-TKIs in NSCLC

PubMed Central

Zhu, Yan-Juan; Zhang, Hai-Bo; Liu, Yi-Hong; Zhu, Ya-Zhen; Chen, Jun; Li, Yong; Bai, Jian-Ping; Liu, Li-Rong; Qu, Yan-Chun; Qu, Xin; Chen, Xian; Zheng, Guang-Juan

2017-01-01

The present study aimed to determine the diagnostic concordance of plasma epidermal growth factor receptor (EGFR) mutation using droplet digital polymerase chain reaction (ddPCR) with tumor tissue samples and the predictive clinical significance of plasma EGFR mutation concentration. Plasma DNA samples from patients with non-small cell lung cancer (NSCLC) were analyzed for EGFR exon 21 codon 858 (L858R) mutation, deletion of exon 19 (ex19del) and exon 20 codon 790 (T790M) mutation using ddPCR. Firstly, the mutations in the plasma samples were compared with the matched tumor samples to determine the concordance. Secondly, image examination follow-ups were analyzed to assess the association between plasma EGFR mutation concentration and patients' response to EGFR-tyrosine kinase inhibitors (TKIs). A total of 51 patients with NSCLC were enrolled, including 48 newly diagnosed patients. Compared with tumor tissue samples, the sensitivity and specificity of ddPCR were 76.19% (16/21) and 96.55% (28/29) for mutant L858R, and 88.89% (8/9) and 100% (41/41) for ex19del, respectively. No patient exhibited the T790M mutation in the tumor tissue or plasma samples. Furthermore, 5 patients with the L858R mutation and 4 patients with ex19del in plasma and tumor tissue samples had been followed up with image examination for ≥3 months following EGFR-TKI treatment. The baseline mutant EGFR concentrations were positively correlated with a reduction in tumor burden (Spearman's r=0.7000, P=0.0358). When analyzed separately, ex19del concentrations (Spearman's r=1.0000, P<0.0001) were also positively correlated with the reduction, while mutant L858R concentrations were not (Spearman's r=0.7000, P=0.1881). In the present study, detection of plasma EGFR mutations using ddPCR exhibited sufficient concordance with tumor tissue sample results. Baseline plasma mutant EGFR and ex19del concentrations were significantly and positively correlated with response to EGFR-TKIs. PMID:28789464

A single digital droplet PCR assay to detect multiple KIT exon 11 mutations in tumor and plasma from patients with gastrointestinal stromal tumors.

PubMed

Boonstra, Pieter A; Ter Elst, Arja; Tibbesma, Marco; Bosman, Lisette J; Mathijssen, Ron; Atrafi, Florence; van Coevorden, Frits; Steeghs, Neeltje; Farag, Sheima; Gelderblom, Hans; van der Graaf, Winette T A; Desar, Ingrid M E; Maier, Jacqueline; Overbosch, Jelle; Suurmeijer, Albert J H; Gietema, Jourik; Schuuring, Ed; Reyners, Anna K L

2018-03-02

Gastrointestinal stromal tumors (GISTs) are characterized by oncogenic KIT mutations that cluster in two exon 11 hotspots. The aim of this study was to develop a single, sensitive, quantitative digital droplet PCR (ddPCR) assay for the detection of common exon 11 mutations in both GIST tumor tissue and in circulating tumor DNA (ctDNA) isolated from GIST patients' plasma. A ddPCR assay was designed using two probes that cover both hotspots. Available archival FFPE tumor tissue from 27 consecutive patients with known KIT exon 11 mutations and 9 randomly selected patients without exon 11 mutations were tested. Plasma samples were prospectively collected in a multicenter bio-databank from December 2014. ctDNA was analyzed of 22 patients with an exon 11 mutation and a baseline plasma sample. The ddPCR assay detected the exon 11 mutation in 21 of 22 tumors with exon 11 mutations covered by the assay. Mutations in ctDNA were detected at baseline in 13 of 14 metastasized patients, but in only 1 of 8 patients with localized disease. In serial plasma samples from 11 patients with metastasized GIST, a decrease in mutant droplets was detected during treatment. According to RECIST 1.1, 10 patients had radiological treatment response and one patient stable disease. A single ddPCR assay for the detection of multiple exon 11 mutations in ctDNA is a feasible, promising tool for monitoring treatment response in patients with metastasized GIST and should be further evaluated in a larger cohort.

[Effect of medicinal-cake-separated moxibustion on functional activity of back-leg and plasma substance P level in patients with lumbar disc herniation].

PubMed

Yang, Shuo; Yang, Xiao-fang; Jiang, Yu; Xiang, Kai-wei; Li, Hai-yu

2014-12-01

To observe the effect of medicinal-cake-separated moxibustion combined with acupuncture on back-leg activities and plasma substance P (SP) levels in patients with lumbar disc herniation, so as to reveal its mechanism underlying pain relief. A total of 114 patients with lumbar disc herniation were randomly divided into control group (n=56) and treatment group (n=58) according to a random digits table. Patients of the control group were treated by manual acupuncture stimulation of main acupoints Jiaji (EX-B 2), Huantiao (GB 30, affected side), Chengshan (BL 57, affected side), Kunlun (BL 60, affected side), and supplemented acupoints Yanglingquan (GB 34), Weizhong (BL 40) and Zusanli (ST 36) in combination with wheat-flour-cake separated moxibustion at the main acupoints, and patients of the treatment group were treated by medicinal-cake [Chuanwu (Radix Aconiti), Caowu (Radix Aconiti Kusnezoffii), Ruxiang (Olibanum), etc. ]-separated moxibustion in combination with manual acupuncture stimulation of the same acupoints mentioned above. Acupuncture treatment was conducted for 30 min, followed by moxibustion for 15 min. The treatment was given once daily for 10 days. The patients' back-leg functional activity ability was assessed using straight-leg raising test, and the pain state assessed using visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) scores, respectively. The therapeutic effect was evaluated by using "Crite- ria for Diagnosis and Outcome Evaluation of Clinical Disorders or Syndromes of Chinese Medicine" issued in 1994 and plasma SP content was detected by radioimmunoassay. After the therapy, the back-leg activity score and JOA score of both groups were significantly higher than those of pre-treatment in the same one group (P<0. 05, P<0. 01), and those of the treatment group were significantly higher than those of the control group (P<0.05). The VAS score of the treatment group was re- markably lower than that of the control group (P<0. 01). After the treatment, the plasma SP content was markedly lower in the treatment group than in the control group (.P<0O. 05 ) . Medicinal-cake-separated moxibustion therapy can ame- liorate pain severity and functional activity of the back-leg pain patients with lumbar disc hernia, which may be related to its effect in reducing blood SP level.

Spectroscopic analysis and control

DOEpatents

Tate; , James D.; Reed, Christopher J.; Domke, Christopher H.; Le, Linh; Seasholtz, Mary Beth; Weber, Andy; Lipp, Charles

2017-04-18

Apparatus for spectroscopic analysis which includes a tunable diode laser spectrometer having a digital output signal and a digital computer for receiving the digital output signal from the spectrometer, the digital computer programmed to process the digital output signal using a multivariate regression algorithm. In addition, a spectroscopic method of analysis using such apparatus. Finally, a method for controlling an ethylene cracker hydrogenator.

Floating-point system quantization errors in digital control systems

NASA Technical Reports Server (NTRS)

Phillips, C. L.; Vallely, D. P.

1978-01-01

This paper considers digital controllers (filters) operating in floating-point arithmetic in either open-loop or closed-loop systems. A quantization error analysis technique is developed, and is implemented by a digital computer program that is based on a digital simulation of the system. The program can be integrated into existing digital simulations of a system.

Network-Physics(NP) Bec DIGITAL(#)-VULNERABILITY Versus Fault-Tolerant Analog

NASA Astrophysics Data System (ADS)

Alexander, G. K.; Hathaway, M.; Schmidt, H. E.; Siegel, E.

2011-03-01

Siegel[AMS Joint Mtg.(2002)-Abs.973-60-124] digits logarithmic-(Newcomb(1881)-Weyl(1914; 1916)-Benford(1938)-"NeWBe"/"OLDbe")-law algebraic-inversion to ONLY BEQS BEC:Quanta/Bosons= digits: Synthesis reveals EMP-like SEVERE VULNERABILITY of ONLY DIGITAL-networks(VS. FAULT-TOLERANT ANALOG INvulnerability) via Barabasi "Network-Physics" relative-``statics''(VS.dynamics-[Willinger-Alderson-Doyle(Not.AMS(5/09)]-]critique); (so called)"Quantum-computing is simple-arithmetic(sans division/ factorization); algorithmic-complexities: INtractibility/ UNdecidability/ INefficiency/NONcomputability / HARDNESS(so MIScalled) "noise"-induced-phase-transitions(NITS) ACCELERATION: Cook-Levin theorem Reducibility is Renormalization-(Semi)-Group fixed-points; number-Randomness DEFINITION via WHAT? Query(VS. Goldreich[Not.AMS(02)] How? mea culpa)can ONLY be MBCS "hot-plasma" versus digit-clumping NON-random BEC; Modular-arithmetic Congruences= Signal X Noise PRODUCTS = clock-model; NON-Shor[Physica A,341,586(04)] BEC logarithmic-law inversion factorization:Watkins number-thy. U stat.-phys.); P=/=NP TRIVIAL Proof: Euclid!!! [(So Miscalled) computational-complexity J-O obviation via geometry.

A spaceborne receiver for measuring electromagnetic field intensity

NASA Technical Reports Server (NTRS)

Reich, B. W.; Van Dusen, M. R.; Habib, E. J.

1973-01-01

Description of a very accurately controlled receiver for monitoring the electromagnetic radiations in both existing and projected space communication bands. Based on analysis of the existing and projected space communication bands, 108 to 174 MHz, 240 to 478 MHz, and 1535 to 1665 MHz were covered. The receiver achieves accurate control via a digitally tuned synthesizer and a wide range of digital control including frequency band coverage and gain control selection. Digital memory was provided to store 16 separate digital command instructions which can be programmed via a command data link. The receiver provides for transmission to the ground of both a predetection signal and signals in digital format, which in turn, were provided by sampling and analog-to-digital conversions.

47 CFR 97.221 - Automatically controlled digital station.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Automatically controlled digital station. 97.221 Section 97.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Special Operations § 97.221 Automatically controlled digital...

Noninvasive Personalization of Lung Cancer Therapy Using a New, Clinical-Grade Assay for Plasma-Based Measurement and Monitoring of Tumor Genotype

DTIC Science & Technology

2016-12-01

Boston MA, 02115-5418 REPORT DATE: December 2016 TYPE OF REPORT: Final PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort...U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION...perform blinded prospective validation of a new assay for noninvasive and quantitative genotyping of cell-free plasma DNA (cfDNA) using droplet digital

Test and control computer user's guide for a digital beam former test system

NASA Technical Reports Server (NTRS)

Alexovich, Robert E.; Mallasch, Paul G.

1992-01-01

A Digital Beam Former Test System was developed to determine the effects of noise, interferers and distortions, and digital implementations of beam forming as applied to the Tracking and Data Relay Satellite 2 (TDRS 2) architectures. The investigation of digital beam forming with application to TDRS 2 architectures, as described in TDRS 2 advanced concept design studies, was conducted by the NASA/Lewis Research Center for NASA/Goddard Space Flight Center. A Test and Control Computer (TCC) was used as the main controlling element of the digital Beam Former Test System. The Test and Control Computer User's Guide for a Digital Beam Former Test System provides an organized description of the Digital Beam Former Test System commands. It is written for users who wish to conduct tests of the Digital Beam forming Test processor using the TCC. The document describes the function, use, and syntax of the TCC commands available to the user while summarizing and demonstrating the use of the commands wtihin DOS batch files.

Investigating plasma viscosity with fast framing photography in the ZaP-HD Flow Z-Pinch experiment

NASA Astrophysics Data System (ADS)

Weed, Jonathan Robert

The ZaP-HD Flow Z-Pinch experiment investigates the stabilizing effect of sheared axial flows while scaling toward a high-energy-density laboratory plasma (HEDLP > 100 GPa). Stabilizing flows may persist until viscous forces dissipate a sheared flow profile. Plasma viscosity is investigated by measuring scale lengths in turbulence intentionally introduced in the plasma flow. A boron nitride turbulence-tripping probe excites small scale length turbulence in the plasma, and fast framing optical cameras are used to study time-evolved turbulent structures and viscous dissipation. A Hadland Imacon 790 fast framing camera is modified for digital image capture, but features insufficient resolution to study turbulent structures. A Shimadzu HPV-X camera captures the evolution of turbulent structures with great spatial and temporal resolution, but is unable to resolve the anticipated Kolmogorov scale in ZaP-HD as predicted by a simplified pinch model.

User guide for the digital control system of the NASA/Langley Research Center's 13-inch Magnetic Suspension and Balance System

NASA Technical Reports Server (NTRS)

Britcher, Colin P.

1987-01-01

The technical background to the development of the digital control system of the NASA/Langley Research Center's 13 inch Magnetic Supension and Balance Systen (MSBS) is reviewed. The implementation of traditional MSBS control algorithms in digital form is examined. Extensive details of the 13-inch MSBS digital controller and related hardware are given, together with the introductory instructions for systems operators. Full listings of software are included in the Appendices.

The development of the miniaturized waveform receiver with the function measuring Antenna Impedance in space plasmas

NASA Astrophysics Data System (ADS)

Ishii, H.; Kojima, H.; Fukuhara, H.; Okada, S.; Yamakawa, H.

2012-04-01

Plasma wave is one of the most essential physical quantities in the solar terrestrial physics. The role of plasma wave receiver onboard satellites is to detect plasma waves in space with a good signal to noise ratio. There are two types of plasma wave receivers, the sweep frequency analyzer and the waveform capture. While the sweep frequency analyzer provides plasma wave spectra, the waveform capture obtains waveforms with phase information that is significant in studying nonlinear phenomena. Antenna sensors to observe electric fields of the plasma waves show different features in plasmas from in vacuum. The antenna impedances have specific characteristics in the frequency domain because of the dispersion of plasmas. These antenna impedances are expressed with complex number. We need to know not only the antenna impedances but also the transfer functions of plasma wave receiver's circuits in order to calibrate observed waveforms precisely. The impedances of the electric field antennas are affected by a state of surrounding plasmas. Since satellites run through various regions with different plasma parameters, we precisely should measure the antenna impedances onboard spacecraft. On the contrary, we can obtain the plasma density and by measuring the antenna impedances. Several formulas of the antenna impedance measurement system were proposed. A synchronous detection method is used on the BepiColombo Mercury Magnetospheric Orbiter (MMO), which will be launched in 2014. The digital data are stored in the onboard memory. They are read out and converted to the analog waveforms by D/A converter. They are fed into the input of the preamplifiers of antenna sensors through a resistor. We can calculate a transfer function of the circuit by applying the synchronous detection method to the output waveform from waveform receivers and digital data as a signal source. The size of this system is same as an A5 board. In recent years, Application Specific Integrated Circuit (ASIC) is in attention which is a technique to integrate large scale and complicated circuits. Lots of ASICs have been applied to high energy astrophysics. In this paper, we show our attempt to miniaturize the antennas impedances measurement system and Waveform Capture using the analogue ASIC. We design 8bits segment D/A converter that is implemented inside the waveform receiver ASIC chip. We improve input logic of the D/A converter to generate very weak signals accurately. The designed chip realizes the measurement of the antenna impedance as well as the waveform observation in the board size of business cards.

Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies - a randomized prospective controlled clinical trial.

PubMed

Geburek, Florian; Gaus, Moritz; van Schie, Hans T M; Rohn, Karl; Stadler, Peter M

2016-09-07

Regenerative and anti-inflammatory effects on tendinopathies have been attributed to blood-derived biologicals. To date the evidence for the efficacy of autologous platelet-rich plasma (PRP) treatment of naturally occurring equine tendinopathies is limited. The purpose of this placebo-controlled clinical trial was to describe the effect of a single treatment of equine superficial digital flexor tendon (SDFT) disease with PRP on clinical and ultrasonographic parameters. Twenty horses with naturally occurring tendinopathies of forelimb SDFTs were randomly assigned to the PRP-treated group (n = 10) or control group (n = 10) after clinical and ultrasonographic examination. The SDFTs received an intralesional treatment with autologous PRP or were injected with saline, respectively (day 0). All horses participated in a standardized exercise programme and were re-examined clinically, with B-mode ultrasonography (5 times at regular intervals) and ultrasound tissue characterization (week 12 and 24 after treatment) until week 24. Long-term performance was estimated via telephone inquiry. Compared to day 0, lameness decreased significantly by week 8 after treatment with PRP and by week 12 in the control group. Ultrasonographically there was no difference in the summarized cross sectional area between the groups at any time point. Ultrasound tissue characterization showed that echo types representing disorganized matrix decreased significantly throughout the observation period in the PRP-treated group. Echo type II, representing discontinuous fascicles, not yet aligned into lines of stress was significantly higher 24 weeks after PRP treatment. Eighty percent of the PRP treated horses reached their previous or a higher level of performance after 12 months compared to 50 % in the CG. After 24 months these proportions were 60 % and 50 %, respectively. A single intralesional treatment with PRP up to 8 weeks after onset of clinical signs of tendinopathy contributes to an earlier reduction of lameness compared to saline treatment and to an advanced organization of repair tissue as the fibrillar matrix is getting organized into fascicles while remodelling continues. Long term, PRP treatment has the potential to increase the number of horses reaching their previous level of performance. Earlier treatment of tendinopathy with PRP should be considered to enhance these effects.

Quantum Cascade Laser Tuning by Digital Micromirror Array-controlled External Cavity

DTIC Science & Technology

2014-01-01

P. Vujkovic-Cvijin, B. Gregor, A. C. Samuels, E. S. Roese, Quantum cascade laser tuning by digital micromirror array-controlled external cavity...REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Quantum cascade laser tuning by digital micromirror array-controlled...dimensional digital micromirror array (DMA) is described. The laser is tuned by modulating the reflectivity of DMA micromirror pixels under computer

Integrated Real-Time Control and Imaging System for Microbiorobotics and Nanobiostructures

DTIC Science & Technology

2016-01-11

kit with a control board and ALP 4.1 basic controller suite. The digital micromirror device is the highest resolution 16:9 aspect ratio system. This...in Figure 1, consisted of the following: (1) digital micromirror device (DMD) and controller, (2) an inverted epifluorescence microscope with a flat...accompanying control board and ALP 4.1 basic controller suite. The digital micromirror device is currently the highest commercially available

Collective behavior of silver plasma during pulsed laser ablation

NASA Astrophysics Data System (ADS)

Dildar, I. M.; Rehman, S.; Khaleeq-ur-Rahman, M.; Bhatti, K. A.; Shuaib, A.

2015-07-01

The present work reports an electrical investigation of silver plasma using a self-fabricated Langmuir probe in air and under a low vacuum (~10-3 torr). A silver target was irradiated with a Q-switched Nd:YAG laser with the wavelength 1.064 µm, energy 10 mJ, pulse duration 9-14 ns and power 1.1 MW. The collective behavior of a silver plasma plume is studied using a Langmuir probe as an electrical diagnostic technique. By applying different positive and negative voltages to the probe, the respective signals are collected on a four channels digital storage oscilloscope having a frequency of 500 MHz. An I-V curve helps to measure electron temperature and electron density directly and plasma frequency, response time, Debye length and number of particles in ‘Debye’s sphere’ indirectly using the theory of Langmuir probe and mathematical formulas. The floating potential is measured as negative for laser induced silver plasma in air and vacuum, following the theory of plasma.

Digital phase-locked-loop speed sensor for accuracy improvement in analog speed controls. [feedback control and integrated circuits

NASA Technical Reports Server (NTRS)

Birchenough, A. G.

1975-01-01

A digital speed control that can be combined with a proportional analog controller is described. The stability and transient response of the analog controller were retained and combined with the long-term accuracy of a crystal-controlled integral controller. A relatively simple circuit was developed by using phase-locked-loop techniques and total error storage. The integral digital controller will maintain speed control accuracy equal to that of the crystal reference oscillator.

HIMAC RF system with a digital synthesizer

NASA Astrophysics Data System (ADS)

Kanazawa, M.; Sato, K.; Itano, A.; Sudou, M.; Noda, K.; Takada, E.; Kumada, M.; Yamazaki, C.; Yamagishi, T.; Morii, Y.; Toyoda, E.; Tsuzuki, N.; Yagi, T.

2000-04-01

An RF acceleration system, in which digital control with a direct digital synthesizer (DDS) is applied, has been developed for the Heavy Ion Medical Accelerator in Chiba (HIMAC) synchrotron. This digital system allows us to obtain stable operation of the acceleration system over a wide frequency range from 1.04 to 7.9 MHz. In this paper the designed digital RF control system and its performance are described.

Propulsion control experience used in the Highly Integrated Digital Electronic Control (HIDEC) program

NASA Technical Reports Server (NTRS)

Myers, L. P.; Burcham, F. W., Jr.

1984-01-01

The highly integrated digital electronic control (HIDEC) program will integrate the propulsion and flight control systems on an F-15 airplane at NASA Ames Research Center's Dryden Flight Research Facility. Ames-Dryden has conducted several propulsion control programs that have contributed to the HIDEC program. The digital electronic engine control (DEEC) flight evaluation investigated the performance and operability of the F100 engine equipped with a full-authority digital electronic control system. Investigations of nozzle instability, fault detection and accommodation, and augmentor transient capability provided important information for the HIDEC program. The F100 engine model derivative (EMD) was also flown in the F-15 airplane, and airplane performance was significantly improved. A throttle response problem was found and solved with a software fix to the control logic. For the HIDEC program, the F100 EMD engines equipped with DEEC controls will be integrated with the digital flight control system. The control modes to be implemented are an integrated flightpath management mode and an integrated adaptive engine control system mode. The engine control experience that will be used in the HIDEC program is discussed.

Field Programmable Gate Array for Implementation of Redundant Advanced Digital Feedback Control

NASA Technical Reports Server (NTRS)

King, K. D.

2003-01-01

The goal of this effort was to develop a digital motor controller using field programmable gate arrays (FPGAs). This is a more rugged approach than a conventional microprocessor digital controller. FPGAs typically have higher radiation (rad) tolerance than both the microprocessor and memory required for a conventional digital controller. Furthermore, FPGAs can typically operate at higher speeds. (While speed is usually not an issue for motor controllers, it can be for other system controllers.) Other than motor power, only a 3.3-V digital power supply was used in the controller; no analog bias supplies were used. Since most of the circuit was implemented in the FPGA, no additional parts were needed other than the power transistors to drive the motor. The benefits that FPGAs provide over conventional designs-lower power and fewer parts-allow for smaller packaging and reduced weight and cost.

Fast and robust control of nanopositioning systems: Performance limits enabled by field programmable analog arrays.

PubMed

Baranwal, Mayank; Gorugantu, Ram S; Salapaka, Srinivasa M

2015-08-01

This paper aims at control design and its implementation for robust high-bandwidth precision (nanoscale) positioning systems. Even though modern model-based control theoretic designs for robust broadband high-resolution positioning have enabled orders of magnitude improvement in performance over existing model independent designs, their scope is severely limited by the inefficacies of digital implementation of the control designs. High-order control laws that result from model-based designs typically have to be approximated with reduced-order systems to facilitate digital implementation. Digital systems, even those that have very high sampling frequencies, provide low effective control bandwidth when implementing high-order systems. In this context, field programmable analog arrays (FPAAs) provide a good alternative to the use of digital-logic based processors since they enable very high implementation speeds, moreover with cheaper resources. The superior flexibility of digital systems in terms of the implementable mathematical and logical functions does not give significant edge over FPAAs when implementing linear dynamic control laws. In this paper, we pose the control design objectives for positioning systems in different configurations as optimal control problems and demonstrate significant improvements in performance when the resulting control laws are applied using FPAAs as opposed to their digital counterparts. An improvement of over 200% in positioning bandwidth is achieved over an earlier digital signal processor (DSP) based implementation for the same system and same control design, even when for the DSP-based system, the sampling frequency is about 100 times the desired positioning bandwidth.

Design and development progress of a LLRF control system for a 500 MHz superconducting cavity

NASA Astrophysics Data System (ADS)

Lee, Y. S.; Kim, H. W.; Song, H. S.; Lee, J. H.; Park, K. H.; Yu, I. H.; Chai, J. S.

2012-07-01

The LLRF (low-level radio-frequency) control system which regulates the amplitude and the phase of the accelerating voltage inside a RF cavity is essential to ensure the stable operation of charged particle accelerators. Recent advances in digital signal processors and data acquisition systems have allowed the LLRF control system to be implemented in digitally and have made it possible to meet the higher demands associated with the performance of LLRF control systems, such as stability, accuracy, etc. For this reason, many accelerator laboratories have completed or are completing the developments of digital LLRF control systems. The digital LLRF control system has advantages related with flexibility and fast reconfiguration. This paper describes the design of the FPGA (field programmable gate array) based LLRF control system and the status of development for this system. The proposed LLRF control system includes an analog front-end, a digital board (ADC (analog to digital converter), DAC (digital to analog converter), FPGA, etc.) and a RF & clock generation system. The control algorithms will be implemented by using the VHDL (VHSIC (very high speed integrated circuits) hardware description language), and the EPICS (experiment physics and industrial control system) will be ported to the host computer for the communication. In addition, the purpose of this system is to control a 500 MHz RF cavity, so the system will be applied to the superconducting cavity to be installed in the PLS storage ring, and its performance will be tested.

Stability of Fiber Optic Networked Decentralized Distributed Engine Control Under Time Delays

DTIC Science & Technology

2009-08-01

Nomenclature FADEC = Full Authority Digital Engine Control D2FADEC = Decentralized Distributed Full Authority Digital Engine Control DEC...Corporation (IFOS), bm@ifos.com. I American Institute of Aeronautics and Astronautics 2 II. Distributed Engine Control Systems FADEC Based on...of Full Authority Digital Engine Control ( FADEC ) are distributed at the component level. Each sensor/actuator is to be replaced by a smart sensor

Active flutter suppression using optical output feedback digital controllers

NASA Technical Reports Server (NTRS)

1982-01-01

A method for synthesizing digital active flutter suppression controllers using the concept of optimal output feedback is presented. A convergent algorithm is employed to determine constrained control law parameters that minimize an infinite time discrete quadratic performance index. Low order compensator dynamics are included in the control law and the compensator parameters are computed along with the output feedback gain as part of the optimization process. An input noise adjustment procedure is used to improve the stability margins of the digital active flutter controller. Sample rate variation, prefilter pole variation, control structure variation and gain scheduling are discussed. A digital control law which accommodates computation delay can stabilize the wing with reasonable rms performance and adequate stability margins.

Research in digital adaptive flight controllers

NASA Technical Reports Server (NTRS)

Kaufman, H.

1976-01-01

A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Both explicit controllers which directly utilize parameter identification and implicit controllers which do not require identification were considered. Extensive analytical and simulation efforts resulted in the recommendation of two explicit digital adaptive flight controllers. Interface weighted least squares estimation procedures with control logic were developed using either optimal regulator theory or with control logic based upon single stage performance indices.

A monitor for the laboratory evaluation of control integrity in digital control systems operating in harsh electromagnetic environments

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

1992-01-01

This paper presents a strategy for dynamically monitoring digital controllers in the laboratory for susceptibility to electromagnetic disturbances that compromise control integrity. The integrity of digital control systems operating in harsh electromagnetic environments can be compromised by upsets caused by induced transient electrical signals. Digital system upset is a functional error mode that involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. The motivation for this work is the need to develop tools and techniques that can be used in the laboratory to validate and/or certify critical aircraft controllers operating in electromagnetically adverse environments that result from lightning, high-intensity radiated fields (HIRF), and nuclear electromagnetic pulses (NEMP). The detection strategy presented in this paper provides dynamic monitoring of a given control computer for degraded functional integrity resulting from redundancy management errors, control calculation errors, and control correctness/effectiveness errors. In particular, this paper discusses the use of Kalman filtering, data fusion, and statistical decision theory in monitoring a given digital controller for control calculation errors.

Implementation of Adaptive Digital Controllers on Programmable Logic Devices

NASA Technical Reports Server (NTRS)

Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Montenegro, Justino (Technical Monitor)

2002-01-01

Much has been made of the capabilities of Field Programmable Gate Arrays (FPGA's) in the hardware implementation of fast digital signal processing functions. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used Proportional-Integral-Derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM- based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a Digital Signal Processor (DSP) device or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using DSP devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, Pulse Width Modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. An alternative is required for compact implementation of such functionality to withstand the harsh environment encountered on spacemap. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive-control algorithm approaches. Radiation tolerant FPGA's are a feasible option for reaching this goal.

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.

Development and implementation of an automated quantitative film digitizer quality control program

NASA Astrophysics Data System (ADS)

Fetterly, Kenneth A.; Avula, Ramesh T. V.; Hangiandreou, Nicholas J.

1999-05-01

A semi-automated, quantitative film digitizer quality control program that is based on the computer analysis of the image data from a single digitized test film was developed. This program includes measurements of the geometric accuracy, optical density performance, signal to noise ratio, and presampled modulation transfer function. The variability of the measurements was less than plus or minus 5%. Measurements were made on a group of two clinical and two laboratory laser film digitizers during a trial period of approximately four months. Quality control limits were established based on clinical necessity, vendor specifications and digitizer performance. During the trial period, one of the digitizers failed the performance requirements and was corrected by calibration.

Floating-point system quantization errors in digital control systems

NASA Technical Reports Server (NTRS)

Phillips, C. L.

1973-01-01

The results are reported of research into the effects on system operation of signal quantization in a digital control system. The investigation considered digital controllers (filters) operating in floating-point arithmetic in either open-loop or closed-loop systems. An error analysis technique is developed, and is implemented by a digital computer program that is based on a digital simulation of the system. As an output the program gives the programing form required for minimum system quantization errors (either maximum of rms errors), and the maximum and rms errors that appear in the system output for a given bit configuration. The program can be integrated into existing digital simulations of a system.

YF-12 cooperative airframe/propulsion control system program, volume 1

NASA Technical Reports Server (NTRS)

Anderson, D. L.; Connolly, G. F.; Mauro, F. M.; Reukauf, P. J.; Marks, R. (Editor)

1980-01-01

Several YF-12C airplane analog control systems were converted to a digital system. Included were the air data computer, autopilot, inlet control system, and autothrottle systems. This conversion was performed to allow assessment of digital technology applications to supersonic cruise aircraft. The digital system was composed of a digital computer and specialized interface unit. A large scale mathematical simulation of the airplane was used for integration testing and software checkout.

Highly personalized detection of minimal Ewing sarcoma disease burden from plasma tumor DNA.

PubMed

Hayashi, Masanori; Chu, David; Meyer, Christian F; Llosa, Nicolas J; McCarty, Gregory; Morris, Carol D; Levin, Adam S; Wolinsky, Jean-Paul; Albert, Catherine M; Steppan, Diana A; Park, Ben Ho; Loeb, David M

2016-10-01

Even though virtually all patients with Ewing sarcoma achieve a radiographic complete response, up to 30% of patients who present with localized disease and up to 90% of those who present with metastases experience a metastatic disease recurrence, highlighting the inability to identify patients with residual disease at the end of therapy. Up to 95% of Ewing sarcomas carry a driving EWS-ETS translocation that has an intronic breakpoint that is specific to each tumor, and the authors developed a system to quantitatively detect the specific breakpoint DNA fragment in patient plasma. The authors used a long-range multiplex polymerase chain reaction (PCR) technique to identify tumor-specific EWS-ETS breakpoints in Ewing sarcoma cell lines, patient-derived xenografts, and patient tumors, and this sequence was used to design tumor-specific primer sets to detect plasma tumor DNA (ptDNA) by droplet digital PCR in xenograft-bearing mice and patients. Tumor-specific breakpoint DNA fragments were detected in the plasma of xenograft-bearing mice, and the signal correlated with tumor burden during primary tumor growth, after surgical resection, and at the time of metastatic disease recurrence. Furthermore, the authors were able to detect the specific breakpoint in plasma DNA obtained from 3 patients with Ewing sarcoma and in 2 patients the authors were able to detect ptDNA when there was radiographically undetectable disease present. The use of droplet digital PCR to detect tumor-specific EWS-ETS fusion gene breakpoint ptDNA fragments can be developed into a highly personalized biomarker of disease recurrence that can be optimized in animal studies for ultimate use in patients. Cancer 2016;122:3015-3023. © 2016 American Cancer Society. © 2016 American Cancer Society.

Bandwidth controller for phase-locked-loop

NASA Technical Reports Server (NTRS)

Brockman, Milton H. (Inventor)

1992-01-01

A phase locked loop utilizing digital techniques to control the closed loop bandwidth of the RF carrier phase locked loop in a receiver provides high sensitivity and a wide dynamic range for signal reception. After analog to digital conversion, a digital phase locked loop bandwidth controller provides phase error detection with automatic RF carrier closed loop tracking bandwidth control to accommodate several modes of transmission.

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.

A Novel Prothrombotic Pathway in Systemic Sclerosis Patients: Possible Role of Bisphosphonate-Activated γδ T Cells

PubMed Central

Marcu-Malina, Victoria; Balbir-Gurman, Alexandra; Dardik, Rima; Braun-Moscovici, Yolanda; Segel, Michael J.; Bank, Ilan

2014-01-01

Objectives: Infusions of aminobisphonates (ABP) activate Vγ9δ2T cells in vivo and induce an acute inflammatory response in 30% of patients treated for osteoporosis. Following the observation of digital thrombosis in a systemic sclerosis (SSc) patient after treatment with an intravenous ABP, zoledronate (Zol), we evaluated whether patient and control peripheral blood (PB) mononuclear cell (MC, PBMC) acquire a prothrombotic phenotype in response to Zol. Results: Vγ9δ2T cells of both patients and healthy donors (HD) upregulated the CD69 activation antigen and secreted tumor necrosis factor (TNF)α in response to Zol in vitro. In addition, exposure to either Zol or lipopolysaccharide (LPS), or to both additively, induced expression of the highly procoagulant, tissue factor (TF)-1 on CD14+ monocytes. Importantly, only Zol-induced TF-1 was blocked by a monoclonal antibody to TNFα. Interestingly, we found that SSc, but not HD, Vδ1+ T cells were concurrently activated by Zol to produce interleukin (IL)-4. Addition of plasma from the blood of the SSc patient who developed critical digital ischemia after infusion of Zol, but neither plasma from a second patient with no adverse clinical response to Zol infusion nor of a HD, strongly enhanced Zol-induced monocyte TF-1, which could still be blocked by anti-TNFα. Conclusion: Aminobisphonates induced secretion of TNFα by Vγ9δ2+ T cells may lead to TNFα-dependent induction of procoagulant TF-1 induction on monocytes. In certain clinical settings, e.g., SSc, TF-1+ monocytes could play a role in triggering clinically relevant thrombosis. PMID:25250025

Digital droplet PCR for rapid quantification of donor DNA in the circulation of transplant recipients as a potential universal biomarker of graft injury.

PubMed

Beck, Julia; Bierau, Sarah; Balzer, Stefan; Andag, Reiner; Kanzow, Philipp; Schmitz, Jessica; Gaedcke, Jochen; Moerer, Onnen; Slotta, Jan E; Walson, Philip; Kollmar, Otto; Oellerich, Michael; Schütz, Ekkehard

2013-12-01

Cell-free DNA (cfDNA) from grafts in the circulation of transplant recipients is a potential biomarker of rejection. Its usefulness was investigated after heart transplantation during the maintenance phase by use of microarrays and massive parallel sequencing of donor and recipient DNA. Disadvantages of these methods are high costs, long turnaround times, and need for donor DNA. Therefore, we sought to develop a rapid and cost-effective method using digital droplet PCR (ddPCR). Plasma samples were collected from stable recipients after liver (LTx, n = 10), kidney (KTx, n = 9), and heart (HTx, n = 8) transplantation as well as from 7 additional patients directly after LTx. Known single-nucleotide polymorphisms were selected for high minor allelic frequencies, of which 41 hydrolysis probe assays were established. Plasma cfDNA was preamplified, followed by conventional real-time PCR to define informative (heterologous) SNPs, which were then used for quantification (percentage) of graft-derived cfDNA (GcfDNA) using ddPCR. Mean recovery was 94% (SD, 13%) with an imprecision of 4%-14% with the use of controls with 2% minor allele. GcfDNA in stable patients was <6.8% (LTx), <2.5% (KTx), and <3.4% (HTx). On the day of LTx, GcfDNA was approximately 90% and by day 10 it was <15% in complication-free LTx recipients. In 2 patients with biopsy-proven rejection, GcfDNA increased to >60%, whereas in 1 patient with cholestasis no increase was found. A novel, cost-effective, rapid technique was developed to quantify GcfDNA in transplant recipients. This technique embodies a promising, potentially universal biomarker for early detection of rejection, which could enable more effective therapeutic interventions.

Analysis of pre-flight modulator voltage calibration data for the Voyager plasma science experiment

NASA Technical Reports Server (NTRS)

Nastov, Ognen

1988-01-01

The Voyager Plasma Science (PLS) modulator calibration (MVM) data analysis was undertaken in order to check the correctness of the fast A/D converter formulas that connect low voltage monitor signals (MV) with digital outputs (DN), to determine the proportionality constants between the actual modulator grid potential (V) and the monitor voltage (MV), and to establish an algorithm to link the digitized readouts (DN) with the actual grid potential (V). The analysis results are surprising in that the derived conversion constants deviate by fairly significant amounts from their nominal values. However, it must be kept in mind that the test results which were used for analysis may be very imprecise. Even if it is assumed that the test result errors are very large, they do no appear to be capable to account for all discrepancies between the theoretical expectations and the results of the analysis. Measurements with the flight spare instrument appear to be the only means of investigating these effects further.

Digitally controlled distributed phase shifter

DOEpatents

Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

1993-08-17

A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

Digitally controlled distributed phase shifter

DOEpatents

Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

1993-01-01

A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

A Nonlinear Digital Control Solution for a DC/DC Power Converter

NASA Technical Reports Server (NTRS)

Zhu, Minshao

2002-01-01

A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

Flight test of a full authority Digital Electronic Engine Control system in an F-15 aircraft

NASA Technical Reports Server (NTRS)

Barrett, W. J.; Rembold, J. P.; Burcham, F. W.; Myers, L.

1981-01-01

The Digital Electronic Engine Control (DEEC) system considered is a relatively low cost digital full authority control system containing selectively redundant components and fault detection logic with capability for accommodating faults to various levels of operational capability. The DEEC digital control system is built around a 16-bit, 1.2 microsecond cycle time, CMOS microprocessor, microcomputer system with approximately 14 K of available memory. Attention is given to the control mode, component bench testing, closed loop bench testing, a failure mode and effects analysis, sea-level engine testing, simulated altitude engine testing, flight testing, the data system, cockpit, and real time display.

Screening for circulating RAS/RAF mutations by multiplex digital PCR.

PubMed

Andersen, Rikke Fredslund; Jakobsen, Anders

2016-07-01

Recent years have shown a large interest in the application of liquid biopsies in cancer management. Circulating tumor DNA (ctDNA) has been investigated for potential use in treatment selection, monitoring of treatment response, and early detection of recurrence. Advances have been hampered by technical challenges primarily due to the low levels of ctDNA in patients with localized disease and in patients responding to therapy. The approach presented here is a multiplex digital PCR method of screening for 31 mutations in the KRAS, NRAS, BRAF, and PIK3CA genes in the plasma. The upper level of the limit of blank, which defines the specificity of the multiplexes, was 0.006%-0.06%. Mutations found by multiplex analyses were identified and quantified by duplex analyses. The method was tested on samples from cholangiocarcinoma patients with known tumor mutational status. Mutations found in the tumor were also found in plasma samples in all cases with analyses for all other mutations being negative. There was a perfect agreement as to wild type status in tumor and plasma. The method combines a high sensitivity with the ability to analyze for several mutations at a time and could be a step towards routine clinical application of liquid biopsies. Copyright © 2016 Elsevier B.V. All rights reserved.

Non-invasive prenatal diagnosis of paternally inherited disorders from maternal plasma: detection of NF1 and CFTR mutations using droplet digital PCR.

PubMed

Gruber, Aurélia; Pacault, Mathilde; El Khattabi, Laila Allach; Vaucouleur, Nicolas; Orhant, Lucie; Bienvenu, Thierry; Girodon, Emmanuelle; Vidaud, Dominique; Leturcq, France; Costa, Catherine; Letourneur, Franck; Anselem, Olivia; Tsatsaris, Vassilis; Goffinet, François; Viot, Géraldine; Vidaud, Michel; Nectoux, Juliette

2018-04-25

To limit risks of miscarriages associated with invasive procedures of current prenatal diagnosis practice, we aim to develop a personalized medicine-based protocol for non-invasive prenatal diagnosis (NIPD) of monogenic disorders relying on the detection of paternally inherited mutations in maternal blood using droplet digital PCR (ddPCR). This study included four couples at risk of transmitting paternal neurofibromatosis type 1 (NF1) mutations and four couples at risk of transmitting compound heterozygous CFTR mutations. NIPD was performed between 8 and 15 weeks of gestation, in parallel to conventional invasive diagnosis. We designed specific hydrolysis probes to detect the paternal mutation and to assess the presence of cell-free fetal DNA by ddPCR. Analytical performances of each assay were determined from paternal sample, an then fetal genotype was inferred from maternal plasma sample. Presence or absence of the paternal mutant allele was correctly determined in all the studied plasma DNA samples. We report an NIPD protocol suitable for implementation in an experienced laboratory of molecular genetics. Our proof-of-principle results point out a high accuracy for early detection of paternal NF1 and CFTR mutations in cell-free DNA, and open new perspectives for extending the technology to NIPD of many other monogenic diseases.

Fetal Genotyping in Maternal Blood by Digital PCR: Towards NIPD of Monogenic Disorders Independently of Parental Origin.

PubMed

Perlado, Sara; Bustamante-Aragonés, Ana; Donas, Marta; Lorda-Sánchez, Isabel; Plaza, Javier; Rodríguez de Alba, Marta

2016-01-01

To date, non-invasive prenatal diagnosis (NIPD) of monogenic disorders has been limited to cases with a paternal origin. This work shows a validation study of the Droplet Digital PCR (ddPCR) technology for analysis of both paternally and maternally inherited fetal alleles. For the purpose, single nucleotide polymorphisms (SNPs) were studied with the only intention to mimic monogenic disorders. NIPD SNP genotyping was performed by ddPCR in 55 maternal plasma samples. In 19 out of 55 cases, inheritance of the paternal allele was determined by presence/absence criteria. In the remaining 36, determination of the maternally inherited fetal allele was performed by relative mutation dosage (RMD) analysis. ddPCR exhibited 100% accuracy for detection of paternal alleles. For diagnosis of fetal alleles with maternal origin by RMD analysis, the technology showed an accuracy of 96%. Twenty-nine out of 36 were correctly diagnosed. There was one FP and six maternal plasma samples that could not be diagnosed. In this study, ddPCR has shown to be capable to detect both paternal and maternal fetal alleles in maternal plasma. This represents a step forward towards the introduction of NIPD for all pregnancies independently of the parental origin of the disease.

Digital control of wind tunnel magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Britcher, Colin P.; Goodyer, Michael J.; Eskins, Jonathan; Parker, David; Halford, Robert J.

1987-01-01

Digital controllers are being developed for wind tunnel magnetic suspension and balance systems, which in turn permit wind tunnel testing of aircraft models free from support interference. Hardware and software features of two existing digital control systems are reviewed. Some aspects of model position sensing and system calibration are also discussed.

COSPAS/SARSAT 406-MHz emergency beacon digital controller

NASA Technical Reports Server (NTRS)

Ivancic, William D.

1988-01-01

The digital control portion of a low-cost 406-MHz COSPAS/SARSAT emergency beacon has been designed and breadboarded at the NASA Lewis Research Center. This report discusses the requirements and design tradeoffs of the digital controller and describes the hardware and software design, which is available only to United States citizens and companies.

77 FR 43405 - Final Standard Review Plan, Branch Technical Position 7-19 on Guidance for Evaluation of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... Digital Computer-Based Instrumentation and Control Systems.'' This BTP is to be cited as the acceptance criteria for Diversity and Defense-in-Depth in Digital Computer-Based Instrumentation and Control Systems... Evaluation of Diversity and Defense-in-Depth in Digital Computer-Based Instrumentation and Control Systems...

A Blood-based Test for the Detection of ROS1 and RET Fusion Transcripts from Circulating Ribonucleic Acid Using Digital Polymerase Chain Reaction

PubMed Central

Mellert, Hestia S.; Alexander, Kristin E.; Jackson, Leisa P.; Pestano, Gary A.

2018-01-01

We have developed novel methods for the isolation and characterization of tumor-derived circulating ribonucleic acid (cRNA) for blood-based liquid biopsy. Robust detection of cRNA recovered from blood represents a solution to a critical unmet need in clinical diagnostics. The test begins with the collection of whole blood into blood collection tubes containing preservatives that stabilize cRNA. Cell-free, exosomal, and platelet-associated RNA is isolated from plasma in this test system. The cRNA is reverse transcribed to complementary DNA (cDNA) and amplified using digital polymerase chain reaction (dPCR). Samples are evaluated for both the target biomarker as well as a control gene. Test validation included limit of detection, accuracy, and robustness studies with analytic samples. The method developed as a result of these studies reproducibly detect multiple fusion variants for ROS1 (C-Ros proto-oncogene 1; 8 variants) and RET (rearranged during transfection proto-oncogene; 8 variants). The sample processing workflow has been optimized so that test results can consistently be generated within 72 hours of sample receipt. PMID:29683453

What can formal methods offer to digital flight control systems design

NASA Technical Reports Server (NTRS)

Good, Donald I.

1990-01-01

Formal methods research begins to produce methods which will enable mathematic modeling of the physical behavior of digital hardware and software systems. The development of these methods directly supports the NASA mission of increasing the scope and effectiveness of flight system modeling capabilities. The conventional, continuous mathematics that is used extensively in modeling flight systems is not adequate for accurate modeling of digital systems. Therefore, the current practice of digital flight control system design has not had the benefits of extensive mathematical modeling which are common in other parts of flight system engineering. Formal methods research shows that by using discrete mathematics, very accurate modeling of digital systems is possible. These discrete modeling methods will bring the traditional benefits of modeling to digital hardware and hardware design. Sound reasoning about accurate mathematical models of flight control systems can be an important part of reducing risk of unsafe flight control.

A digital control system for high level acoustic noise generation

NASA Technical Reports Server (NTRS)

Lee, John P.; Bosco, Jerry H.

1986-01-01

As part of the modernization of the Acoustic Test Facility at Lockheed Missiles and Space Company, Sunnyvale, a digital acoustic control system was designed and built. The requirements imposed by Lockheed on the control system and the degree to which those requirements were met are discussed. Acceptance test results as well as some of the features of the digital control system not found in traditional manual control systems are discussed.

Digital flight control actuation system study

NASA Technical Reports Server (NTRS)

Rossing, R.; Hupp, R.

1974-01-01

Flight control actuators and feedback sensors suitable for use in a redundant digital flight control system were examined. The most appropriate design approach for an advanced digital flight control actuation system for development and use in a fly-by-wire system was selected. The concept which was selected consisted of a PM torque motor direct drive. The selected system is compatible with concurrent and independent development efforts on the computer system and the control law mechanizations.

Multiplex picoliter-droplet digital PCR for quantitative assessment of EGFR mutations in circulating cell-free DNA derived from advanced non-small cell lung cancer patients.

PubMed

Yu, Qian; Huang, Fei; Zhang, Meilin; Ji, Haiying; Wu, Shenchao; Zhao, Ying; Zhang, Chunyan; Wu, Jiong; Wang, Beili; Pan, Baisheng; Zhang, Xin; Guo, Wei

2017-08-01

To explore the possible diagnostic value of liquid biopsy, two multiplex panels using picoliter-droplet digital polymerase chain reaction (ddPCR) were established to quantitatively assess the epidermal growth factor receptor (EGFR) mutations in cell‑free DNA (cfDNA) extracted from the plasma of advanced non‑small cell lung cancer (NSCLC) patients. Plasma samples derived from 22 patients with stage IIIB/IV NSCLC harboring EGFR mutations in matched tumor tissues confirmed by amplification refractory mutation system (ARMS) analysis were subjected to two multiplex ddPCR panels to assess the abundance of tyrosine kinase inhibitor (TKI) ‑sensitive (19DEL, L858R) and TKI‑resistant (T790 M) mutations. Fluctuations in EGFR mutant abundance were monitored by either of the multiplex ddPCR panels for three patients undergoing EGFR‑TKI treatment, with serial plasma sample collections over 2 months. The multiplex ddPCR panels applied to plasma cfDNA from advanced NSCLC patients achieved a total concordance rate of 80% with the EGFR mutation profiles obtained by ARMS from matched biopsy tumor specimens (90% for 19DEL, 95% for L858R, 95% for T790M, respectively) and revealed additional mutant alleles in two subjects. The respective sensitivity and specificity were 90.9 and 88.9% for 19DEL, 87.5 and 100% for L858R, 100 and 93.8% for T790M. The fluctuations of EGFR mutant abundance in serial plasma cfDNA were in accordance with the changes in tumor size as assessed by imaging scans. The authors demonstrated the utility of multiplex ddPCR panels with ultra‑sensitivity for quantitative analysis of EGFR mutations in plasma cfDNA and obtained promising usefulness in EGFR‑TKI decision‑making for advanced NSCLC patients.

Multiplex picoliter-droplet digital PCR for quantitative assessment of EGFR mutations in circulating cell-free DNA derived from advanced non-small cell lung cancer patients

PubMed Central

Yu, Qian; Huang, Fei; Zhang, Meilin; Ji, Haiying; Wu, Shenchao; Zhao, Ying; Zhang, Chunyan; Wu, Jiong; Wang, Beili; Pan, Baisheng; Zhang, Xin; Guo, Wei

2017-01-01

To explore the possible diagnostic value of liquid biopsy, two multiplex panels using picoliter-droplet digital polymerase chain reaction (ddPCR) were established to quantitatively assess the epidermal growth factor receptor (EGFR) mutations in cell-free DNA (cfDNA) extracted from the plasma of advanced non-small cell lung cancer (NSCLC) patients. Plasma samples derived from 22 patients with stage IIIB/IV NSCLC harboring EGFR mutations in matched tumor tissues confirmed by amplification refractory mutation system (ARMS) analysis were subjected to two multiplex ddPCR panels to assess the abundance of tyrosine kinase inhibitor (TKI) -sensitive (19DEL, L858R) and TKI-resistant (T790 M) mutations. Fluctuations in EGFR mutant abundance were monitored by either of the multiplex ddPCR panels for three patients undergoing EGFR-TKI treatment, with serial plasma sample collections over 2 months. The multiplex ddPCR panels applied to plasma cfDNA from advanced NSCLC patients achieved a total concordance rate of 80% with the EGFR mutation profiles obtained by ARMS from matched biopsy tumor specimens (90% for 19DEL, 95% for L858R, 95% for T790M, respectively) and revealed additional mutant alleles in two subjects. The respective sensitivity and specificity were 90.9 and 88.9% for 19DEL, 87.5 and 100% for L858R, 100 and 93.8% for T790M. The fluctuations of EGFR mutant abundance in serial plasma cfDNA were in accordance with the changes in tumor size as assessed by imaging scans. The authors demonstrated the utility of multiplex ddPCR panels with ultra-sensitivity for quantitative analysis of EGFR mutations in plasma cfDNA and obtained promising usefulness in EGFR-TKI decision-making for advanced NSCLC patients. PMID:29067441

Development of Methods for Diagnostics of Discharges in Supersonic Flows

DTIC Science & Technology

2001-09-01

probe. As it was carried out in [I.21] the calculations of equilibrium structure of combustion products of hydrocarbonaceous fuel have shown, that at...fiber line for the required distance and the inverse transformation of the digit code to the analogue signal. New methods of plasma diagnostics are...plasma …. 137 2.3.1 Non-stationary kinetic model of a discharge in a dry air ………………………………………... 140 2.3.2 Results of numerical calculations of gas

A very sensitive ion collection device for plasma-laser characterization.

PubMed

Cavallaro, S; Torrisi, L; Cutroneo, M; Amato, A; Sarta, F; Wen, L

2012-06-01

In this paper a very sensitive ion collection device, for diagnostic of laser ablated-target plasma, is described. It allows for reducing down to few microvolts the signal threshold at digital scope input. A standard ion collector is coupled to a transimpedance amplifier, specially designed, which increases data acquisition sensitivity by a gain ≈1100 and does not introduce any significant distortion of input signal. By time integration of current intensity, an amount of charge as small as 2.7 × 10(-2) pC can be detected for photopeak events.

High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

NASA Astrophysics Data System (ADS)

Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

2013-04-01

High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

Cognitive impairment in rheumatoid arthritis: role of lymphocyte subsets, cytokines and neurotrophic factors.

PubMed

Petersen, Laura E; Baptista, Talita S A; Molina, Júlia K; Motta, Julia G; do Prado, Aline; Piovesan, Deise M; de Nardi, Tatiana; Viola, Thiago W; Vieira, Érica L M; Teixeira, Antonio L; Grassi-Oliveira, Rodrigo; Bauer, Moisés Evandro

2018-05-01

To what extent the cognitive impairment of rheumatoid arthritis (RA) is modulated by autoimmune and/or inflammatory activity is largely unknown. The aim of this study was to investigate the role of peripheral inflammation on cognitive functions of patients with active (Ac-), controlled (Co-) RA and healthy controls. In a cross-sectional study, 102 RA patients and 30 matched healthy controls were recruited. B and T cell subsets were immunophenotyped by flow cytometry. Plasma cytokines and neurotrophins were measured by flow cytometry and ELISA, respectively. Cognitive performance, depression and stress were evaluated by structured clinical interviews. Generalized linear modeling (GzLM) was used to compare differences between groups and multiple linear regression models were used to explore the predictive value of immune variables on cognitive performance. RA patients had overall cognitive impairment. Of note, the Ac-RA had the poorest performance on digit span (DST) and N-back when compared to Co-RA and control group (DST 9.9 ± 2.1, 12.9 ± 4.2, 15.5 ± 4.7, respectively; N-back 49.2 ± 8.3, 55.5 ± 11.1, 60.8 ± 9.1, respectively, all p < 0.0001). RA patients had expansions of immature B cells (Ac-RA 11.2 ± 7.1, Co-RA: 9 ± 5.7, control 5.9 ± 2.1) and plasma cells (Ac-RA 5.2 ± 2.5, Co-RA 6.9 ± 3.7, control 2.8 ± 1.7) as compared to controls, all p < 0.05. RA patients (controlled and active disease) had higher plasma levels of TNF, IL-2, IL-4, IL-6 and IL-10 than controls (all p < 0.002). RA patients had higher BDNF levels (Ac-RA 17,354.4 ± 5357.3, Co-RA 13,841.2 ± 5953.7, control 11,543.3 ± 3772), but lower GDNF levels [median (interquartile range) Ac-RA 0 pg/ml (0.0), Co-RA 0 pg/ml (4.6) and control 4.7 pg/ml (18.1)] than controls (all p < 0.05). RA patients had global cognitive impairment, which was associated with disease activity and immune changes.

Precision digital control systems

NASA Astrophysics Data System (ADS)

Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

Digital control of diode laser for atmospheric spectroscopy

NASA Technical Reports Server (NTRS)

Menzies, R. T.; Rutledge, C. W. (Inventor)

1985-01-01

A system is described for remote absorption spectroscopy of trace species using a diode laser tunable over a useful spectral region of 50 to 200 cm(-1) by control of diode laser temperature over range from 15 K to 100 K, and tunable over a smaller region of typically 0.1 to 10 cm(-1) by control of the diode laser current over a range from 0 to 2 amps. Diode laser temperature and current set points are transmitted to the instrument in digital form and stored in memory for retrieval under control of a microprocessor during measurements. The laser diode current is determined by a digital to analog converter through a field effect transistor for a high degree of ambient temperature stability, while the laser diode temperature is determined by set points entered into a digital to analog converter under control of the microprocessor. Temperature of the laser diode is sensed by a sensor diode to provide negative feedback to the temperature control circuit that responds to the temperature control digital to analog converter.

First results from gamma ray diagnostics in EAST Tokamak

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

Zhou, R. J.; Hu, L. Q.; Zhong, G. Q., E-mail: gqzhong@ipp.ac.cn

2016-11-15

Gamma ray diagnostics has been developed in the EAST tokamak recently. Six BGO scintillator detectors are arranged on the down-half cross-section and pointed at the up-half cross-section of plasma, with space resolution about 15 cm and energy range from 0.3 MeV to 6 MeV. Three main gamma ray peaks in the energy spectra have been observed and are identified as the results of nuclear reactions {sup 207}Pb(n, n′){sup 207m}Pb, H(n, γ) D, and D(p, γ){sup 3}He, respectively. Upgrading of the system is in progress by using LaBr3(Ce) scintillator, fast photo-multiplier tubes, and a fully digital data acquisition system based onmore » high sample frequency digitizers with digital pulse processing algorithms.« less

Digitally controlled analog proportional-integral-derivative (PID) controller for high-speed scanning probe microscopy

NASA Astrophysics Data System (ADS)

Dukic, Maja; Todorov, Vencislav; Andany, Santiago; Nievergelt, Adrian P.; Yang, Chen; Hosseini, Nahid; Fantner, Georg E.

2017-12-01

Nearly all scanning probe microscopes (SPMs) contain a feedback controller, which is used to move the scanner in the direction of the z-axis in order to maintain a constant setpoint based on the tip-sample interaction. The most frequently used feedback controller in SPMs is the proportional-integral (PI) controller. The bandwidth of the PI controller presents one of the speed limiting factors in high-speed SPMs, where higher bandwidths enable faster scanning speeds and higher imaging resolution. Most SPM systems use digital signal processor-based PI feedback controllers, which require analog-to-digital and digital-to-analog converters. These converters introduce additional feedback delays which limit the achievable imaging speed and resolution. In this paper, we present a digitally controlled analog proportional-integral-derivative (PID) controller. The controller implementation allows tunability of the PID gains over a large amplification and frequency range, while also providing precise control of the system and reproducibility of the gain parameters. By using the analog PID controller, we were able to perform successful atomic force microscopy imaging of a standard silicon calibration grating at line rates up to several kHz.

Digitally controlled analog proportional-integral-derivative (PID) controller for high-speed scanning probe microscopy.

PubMed

Dukic, Maja; Todorov, Vencislav; Andany, Santiago; Nievergelt, Adrian P; Yang, Chen; Hosseini, Nahid; Fantner, Georg E

2017-12-01

Nearly all scanning probe microscopes (SPMs) contain a feedback controller, which is used to move the scanner in the direction of the z-axis in order to maintain a constant setpoint based on the tip-sample interaction. The most frequently used feedback controller in SPMs is the proportional-integral (PI) controller. The bandwidth of the PI controller presents one of the speed limiting factors in high-speed SPMs, where higher bandwidths enable faster scanning speeds and higher imaging resolution. Most SPM systems use digital signal processor-based PI feedback controllers, which require analog-to-digital and digital-to-analog converters. These converters introduce additional feedback delays which limit the achievable imaging speed and resolution. In this paper, we present a digitally controlled analog proportional-integral-derivative (PID) controller. The controller implementation allows tunability of the PID gains over a large amplification and frequency range, while also providing precise control of the system and reproducibility of the gain parameters. By using the analog PID controller, we were able to perform successful atomic force microscopy imaging of a standard silicon calibration grating at line rates up to several kHz.

A novel method to optimize the mode spectrum of the dynamic resonant magnetic perturbation on the J-TEXT tokamak.

PubMed

Yi, B; Rao, B; Ding, Y H; Li, M; Xu, H Y; Zhang, M; Zhuang, G; Pan, Y

2014-11-01

The dynamic resonant magnetic perturbation (DRMP) system has been developed for the J-TEXT tokamak to study the interaction between the rotating perturbation magnetic field and the plasma. When the DRMP coils are energized by two phase sinusoidal currents with the same frequency, a 2/1 rotating resonant magnetic perturbation component will be generated. But at the same time, a small perturbation component rotating in the opposite direction is also produced because of the control error of the currents. This small component has bad influence on the experiment investigations. Actually, the mode spectrum of the generated DRMP can be optimized with an accurate control of phase difference between the two currents. In this paper, a new phase control method based on a novel all-digital phase-locked loop (ADPLL) is proposed. The proposed method features accurate phase control and flexible phase adjustment. Modeling and analysis of the proposed ADPLL is presented to guide the design of the parameters of the phase controller in order to obtain a better performance. Testing results verify the effectiveness of the ADPLL and validity of the method applying to the DRMP system.

A novel method to optimize the mode spectrum of the dynamic resonant magnetic perturbation on the J-TEXT tokamak

NASA Astrophysics Data System (ADS)

Yi, B.; Rao, B.; Ding, Y. H.; Li, M.; Xu, H. Y.; Zhang, M.; Zhuang, G.; Pan, Y.

2014-11-01

The dynamic resonant magnetic perturbation (DRMP) system has been developed for the J-TEXT tokamak to study the interaction between the rotating perturbation magnetic field and the plasma. When the DRMP coils are energized by two phase sinusoidal currents with the same frequency, a 2/1 rotating resonant magnetic perturbation component will be generated. But at the same time, a small perturbation component rotating in the opposite direction is also produced because of the control error of the currents. This small component has bad influence on the experiment investigations. Actually, the mode spectrum of the generated DRMP can be optimized with an accurate control of phase difference between the two currents. In this paper, a new phase control method based on a novel all-digital phase-locked loop (ADPLL) is proposed. The proposed method features accurate phase control and flexible phase adjustment. Modeling and analysis of the proposed ADPLL is presented to guide the design of the parameters of the phase controller in order to obtain a better performance. Testing results verify the effectiveness of the ADPLL and validity of the method applying to the DRMP system.

Digital robust control law synthesis using constrained optimization

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivekananda

1989-01-01

Development of digital robust control laws for active control of high performance flexible aircraft and large space structures is a research area of significant practical importance. The flexible system is typically modeled by a large order state space system of equations in order to accurately represent the dynamics. The active control law must satisy multiple conflicting design requirements and maintain certain stability margins, yet should be simple enough to be implementable on an onboard digital computer. Described here is an application of a generic digital control law synthesis procedure for such a system, using optimal control theory and constrained optimization technique. A linear quadratic Gaussian type cost function is minimized by updating the free parameters of the digital control law, while trying to satisfy a set of constraints on the design loads, responses and stability margins. Analytical expressions for the gradients of the cost function and the constraints with respect to the control law design variables are used to facilitate rapid numerical convergence. These gradients can be used for sensitivity study and may be integrated into a simultaneous structure and control optimization scheme.

RAS testing of liquid biopsy correlates with the outcome of metastatic colorectal cancer patients treated with first-line FOLFIRI plus cetuximab in the CAPRI-GOIM trial.

PubMed

Normanno, N; Esposito Abate, R; Lambiase, M; Forgione, L; Cardone, C; Iannaccone, A; Sacco, A; Rachiglio, A M; Martinelli, E; Rizzi, D; Pisconti, S; Biglietto, M; Bordonaro, R; Troiani, T; Latiano, T P; Giuliani, F; Leo, S; Rinaldi, A; Maiello, E; Ciardiello, F

2018-01-01

Liquid biopsy is an alternative to tissue for RAS testing in metastatic colorectal carcinoma (mCRC) patients. Little information is available on the predictive role of liquid biopsy RAS testing in patients treated with first-line anti-EGFR monoclonal antibody-based therapy. In the CAPRI-GOIM trial, 340 KRAS exon-2 wild-type mCRC patients received first-line cetuximab plus FOLFIRI. Tumor samples were retrospectively assessed by next generation sequencing (NGS). Baseline plasma samples were analyzed for KRAS and NRAS mutations using beads, emulsion, amplification, and magnetics digital PCR (BEAMing). Discordant cases were solved by droplet digital PCR (ddPCR) or deep-sequencing. A subgroup of 92 patients with available both NGS data on tumor samples and baseline plasma samples were included in this study. Both NGS analysis of tumor tissue and plasma testing with BEAMing identified RAS mutations in 33/92 patients (35.9%). However, 10 cases were RAS tissue mutant and plasma wild-type, and additional 10 cases were tissue wild-type and plasma mutant, resulting in a concordance rate of 78.3%. Analysis of plasma samples with ddPCR detected RAS mutations in 2/10 tissue mutant, plasma wild-type patients. In contrast, in all tissue wild-type and plasma mutant cases, ddPCR or deep-sequencing analysis of tumor tissue confirmed the presence of RAS mutations at allelic frequencies ranging between 0.15% and 1.15%. The median progression-free survival of RAS mutant and wild-type patients according to tissue (7.9 versus 12.6 months; P = 0.004) and liquid biopsy testing (7.8 versus 13.8 moths; P < 0.001) were comparable. Similar findings were observed for the median overall survival of RAS mutant and wild-type patients based on tissue (22.1 versus 35.8 months; P = 0.016) and plasma (19.9 versus 35.8 months; P = 0.013) analysis. This study indicates that RAS testing of liquid biopsy results in a similar outcome when compared with tissue testing in mCRC patients receiving first-line anti-EGFR monoclonal antibodies. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Designed cell consortia as fragrance-programmable analog-to-digital converters.

PubMed

Müller, Marius; Ausländer, Simon; Spinnler, Andrea; Ausländer, David; Sikorski, Julian; Folcher, Marc; Fussenegger, Martin

2017-03-01

Synthetic biology advances the rational engineering of mammalian cells to achieve cell-based therapy goals. Synthetic gene networks have nearly reached the complexity of digital electronic circuits and enable single cells to perform programmable arithmetic calculations or to provide dynamic remote control of transgenes through electromagnetic waves. We designed a synthetic multilayered gaseous-fragrance-programmable analog-to-digital converter (ADC) allowing for remote control of digital gene expression with 2-bit AND-, OR- and NOR-gate logic in synchronized cell consortia. The ADC consists of multiple sampling-and-quantization modules sensing analog gaseous fragrance inputs; a gas-to-liquid transducer converting fragrance intensity into diffusible cell-to-cell signaling compounds; a digitization unit with a genetic amplifier circuit to improve the signal-to-noise ratio; and recombinase-based digital expression switches enabling 2-bit processing of logic gates. Synthetic ADCs that can remotely control cellular activities with digital precision may enable the development of novel biosensors and may provide bioelectronic interfaces synchronizing analog metabolic pathways with digital electronics.

Dynamical beam manipulation based on 2-bit digitally-controlled coding metasurface.

PubMed

Huang, Cheng; Sun, Bo; Pan, Wenbo; Cui, Jianhua; Wu, Xiaoyu; Luo, Xiangang

2017-02-08

Recently, a concept of digital metamaterials has been proposed to manipulate field distribution through proper spatial mixtures of digital metamaterial bits. Here, we present a design of 2-bit digitally-controlled coding metasurface that can effectively modulate the scattered electromagnetic wave and realize different far-field beams. Each meta-atom of this metasurface integrates two pin diodes, and by tuning their operating states, the metasurface has four phase responses of 0, π/2, π, and 3π/2, corresponding to four basic digital elements "00", "01", "10", and "11", respectively. By designing the coding sequence of the above digital element array, the reflected beam can be arbitrarily controlled. The proposed 2-bit digital metasurface has been demonstrated to possess capability of achieving beam deflection, multi-beam and beam diffusion, and the dynamical switching of these different scattering patterns is completed by a programmable electric source.

Dynamical beam manipulation based on 2-bit digitally-controlled coding metasurface

PubMed Central

Huang, Cheng; Sun, Bo; Pan, Wenbo; Cui, Jianhua; Wu, Xiaoyu; Luo, Xiangang

2017-01-01

Recently, a concept of digital metamaterials has been proposed to manipulate field distribution through proper spatial mixtures of digital metamaterial bits. Here, we present a design of 2-bit digitally-controlled coding metasurface that can effectively modulate the scattered electromagnetic wave and realize different far-field beams. Each meta-atom of this metasurface integrates two pin diodes, and by tuning their operating states, the metasurface has four phase responses of 0, π/2, π, and 3π/2, corresponding to four basic digital elements “00”, “01”, “10”, and “11”, respectively. By designing the coding sequence of the above digital element array, the reflected beam can be arbitrarily controlled. The proposed 2-bit digital metasurface has been demonstrated to possess capability of achieving beam deflection, multi-beam and beam diffusion, and the dynamical switching of these different scattering patterns is completed by a programmable electric source. PMID:28176870

Automation of extrusion of porous cable products based on a digital controller

NASA Astrophysics Data System (ADS)

Chostkovskii, B. K.; Mitroshin, V. N.

2017-07-01

This paper presents a new approach to designing an automated system for monitoring and controlling the process of applying porous insulation material on a conductive cable core, which is based on using structurally and parametrically optimized digital controllers of an arbitrary order instead of calculating typical PID controllers using known methods. The digital controller is clocked by signals from the clock length sensor of a measuring wheel, instead of a timer signal, and this provides the robust properties of the system with respect to the changing insulation speed. Digital controller parameters are tuned to provide the operating parameters of the manufactured cable using a simulation model of stochastic extrusion and are minimized by moving a regular simplex in the parameter space of the tuned controller.

F-15 digital electronic engine control system description

NASA Technical Reports Server (NTRS)

Myers, L. P.

1984-01-01

A digital electronic engine control (DEEC) was developed for use on the F100-PW-100 turbofan engine. This control system has full authority control, capable of moving all the controlled variables over their full ranges. The digital computational electronics and fault detection and accomodation logic maintains safe engine operation. A hydromechanical backup control (BUC) is an integral part of the fuel metering unit and provides gas generator control at a reduced performance level in the event of an electronics failure. The DEEC's features, hardware, and major logic diagrams are described.

Apollo guidance, navigation and control: Guidance system operations plan for manned CM earth orbital and lunar missions using Program COLOSSUS 3. Section 3: Digital autopilots (revision 14)

NASA Technical Reports Server (NTRS)

1972-01-01

Digital autopilots for the manned command module earth orbital and lunar missions using program COLOSSUS 3 are discussed. Subjects presented are: (1) reaction control system digital autopilot, (2) thrust vector control autopilot, (3) entry autopilot and mission control programs, (4) takeover of Saturn steering, and (5) coasting flight attitude maneuver routine.

LAPTAG: Los Angeles Physics Teachers Alliance Group and the UCLA Basic Plasma User Facility.

NASA Astrophysics Data System (ADS)

Gekelman, Walter

2001-10-01

LAPTAG was founded in 1993 during a meeting sponsored by the APS, which encouraged high schools and Universities to form alliances. There are currently about twenty high schools, several community colleges and two Universities (UCLA and USC) involved. At first LAPTAG organized tours of laboratories at UCLA, USC, JPL, General Atomics and the Mt. Wilson Observatory and had meetings in which issues on curricula were discussed. It became obvious after awhile that in order for the group to last that projects were necessary. An early project involved having the high school faculty and students create Websites for most of the schools. This was before most the schools could afford Internet connections and Web authoring tools did not exist. Then with funding from the UC Office of the President, a seismology project was initiated and ten schools received seismometers. There were lectures by geologists and staff members of the Southern California Earthquake center; results were reported on the Web. In the spring of 1999 LAPTAG gave seven posters at the Condensed Matter APS meeting in Los Angeles. A web based astronomy course was created and high school students controlled the Mount Wilson telescope remotely and studied a variable star. Our latest project, funded by the Department of Energy resulted in the construction of a plasma lab dedicated to LAPTAG. The lab has equipment that is used by practicing plasma physicists (tone-burst generators, digital scopes, digital data acquisition and computerized probe drives) as well as software (LabView, PVwave). The high school students and teachers built the machine and all the associated diagnostics. Examples of the experiments will be given, however it is not a cookbook lab. As new experiments are introduced the same difficulties we all face must be overcome; the students take part in this. The LAPD laboratory is now a National User Facility and LAPTAG is a key component of its outreach program. We have met with the director of science for the Los Angeles Unified School district, and others, to muster resources to allow many more schools to participate. This and plans for other programs such as the Integration of Art and Science, will be presented.

Anticipatory planning and control of grasp positions and forces for dexterous two-digit manipulation.

PubMed

Fu, Qiushi; Zhang, Wei; Santello, Marco

2010-07-07

Dexterous object manipulation requires anticipatory control of digit positions and forces. Despite extensive studies on sensorimotor learning of digit forces, how humans learn to coordinate digit positions and forces has never been addressed. Furthermore, the functional role of anticipatory modulation of digit placement to object properties remains to be investigated. We addressed these questions by asking human subjects (12 females, 12 males) to grasp and lift an inverted T-shaped object using precision grip at constrained or self-chosen locations. The task requirement was to minimize object roll during lift. When digit position was not constrained, subjects could have implemented many equally valid digit position-force coordination patterns. However, choice of digit placement might also have resulted in large trial-to-trial variability of digit position, hence challenging the extent to which the CNS could have relied on sensorimotor memories for anticipatory control of digit forces. We hypothesized that subjects would modulate digit placement for optimal force distribution and digit forces as a function of variable digit positions. All subjects learned to minimize object roll within the first three trials, and the unconstrained device was associated with significantly smaller grip forces but larger variability of digit positions. Importantly, however, digit load force modulation compensated for position variability, thus ensuring consistent object roll minimization on each trial. This indicates that subjects learned object manipulation by integrating sensorimotor memories with sensory feedback about digit positions. These results are discussed in the context of motor equivalence and sensorimotor integration of grasp kinematics and kinetics.

A novel emissive projection display (EPD) on transparent phosphor screen

NASA Astrophysics Data System (ADS)

Cheng, Botao; Sun, Leonard; Yu, Ge; Sun, Ted X.

2017-03-01

A new paradigm of digital projection is on the horizon, based on innovative emissive screen that are made fully transparent. It can be readily applied and convert any surface to a high image quality emissive digital display, without affecting the surface appearance. For example, it can convert any glass window or windshield to completely see-through display, with unlimited field of view and viewing angles. It also enables a scalable and economic projection display on a pitch-black emissive screen with black level and image contrast that rivals other emissive displays such as plasma display or OLED.

Arc-An OAI Service Provider for Digital Library Federation; Kepler-An OAI Data/Service Provider for the Individual; Information Objects and Rights Management: A Mediation-Based Approach to DRM Interoperability; Automated Name Authority Control and Enhanced Searching in the Levy Collection; Renardus Project Developments and the Wider Digital Library Context.

ERIC Educational Resources Information Center

Liu, Xiaoming; Maly, Kurt; Zubair, Mohammad; Nelson, Michael L.; Erickson, John S.; DiLauro, Tim; Choudhury, G. Sayeed; Patton, Mark; Warner, James W.; Brown, Elizabeth W.; Heery, Rachel; Carpenter, Leona; Day, Michael

2001-01-01

Includes five articles that discuss the OAI (Open Archive Initiative), an interface between data providers and service providers; information objects and digital rights management interoperability; digitizing library collections, including automated name authority control, metadata, and text searching engines; and building digital library services…

ISIS Topside-Sounder Plasma-Wave Investigations as Guides to Desired Virtual Wave Observatory (VWO) Data Search Capabilities

NASA Technical Reports Server (NTRS)

Benson, Robert F.; Fung, Shing F.

2008-01-01

Many plasma-wave phenomena, observed by space-borne radio sounders, cannot be properly explained in terms of wave propagation in a cold plasma consisting of mobile electrons and infinitely massive positive ions. These phenomena include signals known as plasma resonances. The principal resonances at the harmonics of the electron cyclotron frequency, the plasma frequency, and the upper-hybrid frequency are well explained by the warm-plasma propagation of sounder-generated electrostatic waves, Other resonances have been attributed to sounder-stimulated plasma instability and non-linear effects, eigenmodes of cylindrical electromagnetic plasma oscillations, and plasma memory processes. Data from the topside sounders of the International Satellites for Ionospheric Studies (ISIS) program played a major role in these interpretations. A data transformation and preservation effort at the Goddard Space Flight Center has produced digital ISIS topside ionograms and a metadata search program that has enabled some recent discoveries pertaining to the physics of these plasma resonances. For example, data records were obtained that enabled the long-standing question (several decades) of the origin of the plasma resonance at the fundamental electron cyclotron frequency to be explained [Muldrew, Radio Sci., 2006]. These data-search capabilities, and the science enabled by them, will be presented as a guide to desired data search capabilities to be included in the Virtual Wave Observatory (VWO).

Multiplex KRASG12/G13 mutation testing of unamplified cell-free DNA from the plasma of patients with advanced cancers using droplet digital polymerase chain reaction.

PubMed

Janku, F; Huang, H J; Fujii, T; Shelton, D N; Madwani, K; Fu, S; Tsimberidou, A M; Piha-Paul, S A; Wheler, J J; Zinner, R G; Naing, A; Hong, D S; Karp, D D; Cabrilo, G; Kopetz, E S; Subbiah, V; Luthra, R; Kee, B K; Eng, C; Morris, V K; Karlin-Neumann, G A; Meric-Bernstam, F

2017-03-01

Cell-free DNA (cfDNA) from plasma offers easily obtainable material for KRAS mutation analysis. Novel, multiplex, and accurate diagnostic systems using small amounts of DNA are needed to further the use of plasma cfDNA testing in personalized therapy. Samples of 16 ng of unamplified plasma cfDNA from 121 patients with diverse progressing advanced cancers were tested with a KRASG12/G13 multiplex assay to detect the seven most common mutations in the hotspot of exon 2 using droplet digital polymerase chain reaction (ddPCR). The results were retrospectively compared to mutation analysis of archival primary or metastatic tumor tissue obtained at different points of clinical care. Eighty-eight patients (73%) had KRASG12/G13 mutations in archival tumor specimens collected on average 18.5 months before plasma analysis, and 78 patients (64%) had KRASG12/G13 mutations in plasma cfDNA samples. The two methods had initial overall agreement in 103 (85%) patients (kappa, 0.66; ddPCR sensitivity, 84%; ddPCR specificity, 88%). Of the 18 discordant cases, 12 (67%) were resolved by increasing the amount of cfDNA, using mutation-specific probes, or re-testing the tumor tissue, yielding overall agreement in 115 patients (95%; kappa 0.87; ddPCR sensitivity, 96%; ddPCR specificity, 94%). The presence of ≥ 6.2% of KRASG12/G13 cfDNA in the wild-type background was associated with shorter survival (P = 0.001). Multiplex detection of KRASG12/G13 mutations in a small amount of unamplified plasma cfDNA using ddPCR has good sensitivity and specificity and good concordance with conventional clinical mutation testing of archival specimens. A higher percentage of mutant KRASG12/G13 in cfDNA corresponded with shorter survival. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Quiet Clean Short-haul Experimental Engine (QCSEE) over-the-wing control system design report

NASA Technical Reports Server (NTRS)

1977-01-01

A control system incorporating a digital electronic control was designed for the over-the-wing engine. The digital electronic control serves as the primary controlling element for engine fuel flow and core compressor stator position. It also includes data monitoring capability, a unique failure indication and corrective action feature, and optional provisions for operating with a new type of servovalve designed to operate in response to a digital-type signal and to fail with its output device hydraulically locked into position.

Report on Disclosure Issues Related to the Use of Copy Control and Digital Rights Management Technologies. OECD Digital Economy Papers, No. 115

ERIC Educational Resources Information Center

OECD Publishing (NJ1), 2006

2006-01-01

This report analyses the disclosure issues raised by technically-imposed restrictions on the use of digital content. It focuses on the application of copy control and digital rights management technologies in three areas: copy-protected CDs; online music, and DVD regional coding. In each of these areas, the report examines the kinds of…

Implementation of Adaptive Digital Controllers on Programmable Logic Devices

NASA Technical Reports Server (NTRS)

Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Ormsby, John (Technical Monitor)

2002-01-01

Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing (DSP) functions. Such capability also makes and FPGA a suitable platform for the digital implementation of closed loop controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM- based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance in a compact form-factor. Other researchers have presented the notion that a second order digital filter with proportional-integral-derivative (PID) control functionality can be implemented in an FPGA. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSF) devices. Our goal is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. Meeting our goals requires alternative compact implementation of such functionality to withstand the harsh environment encountered on spacecraft. Radiation tolerant FPGA's are a feasible option for reaching these goals.

Controlled-Root Approach To Digital Phase-Locked Loops

NASA Technical Reports Server (NTRS)

Stephens, Scott A.; Thomas, J. Brooks

1995-01-01

Performance tailored more flexibly and directly to satisfy design requirements. Controlled-root approach improved method for analysis and design of digital phase-locked loops (DPLLs). Developed rigorously from first principles for fully digital loops, making DPLL theory and design simpler and more straightforward (particularly for third- or fourth-order DPLL) and controlling performance more accurately in case of high gain.

AVIRIS onboard data handling and control

NASA Technical Reports Server (NTRS)

Steinkraus, Ronald E.; Hickok, Roger W.

1987-01-01

The timing and flow of detector and ancillary data for the Airborne Visible/Infrared imaging spectrometer (AVIRIS) are controlled within the instrument by its digital electronics assembly. In addition to providing detector and signal chain timing, the digital electronics receives, formats, and rate-buffers digitized science data; collects and formats ancillary (calibration and engineering) data; and merges both into a single tape record. Overall AVIRIS data handling is effected by a combination of dedicated digital electronics to control instrument timing, image data flow, and data rate buffering and a microcomputer programmed to handle real-time control of instrument mechanisms and the coordinated preparation of ancillary data.

Development and testing of methodology for evaluating the performance of multi-input/multi-output digital control systems

NASA Technical Reports Server (NTRS)

Polotzky, Anthony S.; Wieseman, Carol; Hoadley, Sherwood Tiffany; Mukhopadhyay, Vivek

1990-01-01

The development of a controller performance evaluation (CPE) methodology for multiinput/multioutput digital control systems is described. The equations used to obtain the open-loop plant, controller transfer matrices, and return-difference matrices are given. Results of applying the CPE methodology to evaluate MIMO digital flutter suppression systems being tested on an active flexible wing wind-tunnel model are presented to demonstrate the CPE capability.

Migration of Older to New Digital Control Systems in Nuclear Power Plant Main Control Rooms

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

Kovesdi, Casey Robert; Joe, Jeffrey Clark

The United States (U.S.) Department of Energy (DOE) Office of Nuclear Energy (NE) has the primary mission to advance nuclear power by resolving socio-technical issues through research and development (R&D). One DOE-NE activity supporting this mission is the Light Water Reactor Sustainability (LWRS) program. LWRS has the overall objective to sustain the operation of existing commercial nuclear power plants (NPPs) through conducting R&D across multiple “pathways,” or R&D focus areas. The Advanced Instrumentation, Information, and Control (II&C) Systems Technologies pathway conducts targeted R&D to address aging and reliability concerns with the legacy instrumentation and control (I&C) and related information systemsmore » in operating U.S. NPPs. This work involves (1) ensuring that legacy analog II&C systems are not life-limiting issues for the LWR fleet, and (2) implementing digital II&C technology in a manner that enables broad innovation and business improvement in the NPP operating model. Under the LWRS Advanced II&C pathway, Human Factors experts at Idaho National Laboratory (INL) have been conducting R&D in support of NPP main control room (MCR) modernization activities. Work in prior years has focused on migrating analog I&C systems to new digital I&C systems (). In fiscal year 2016 (FY16), one new focus area for this research is migrating older digital I&C systems to new and advanced digital I&C systems. This report summarizes a plan for conducting a digital-to-digital migration of a legacy digital I&C system to a new digital I&C system in support of control room modernization activities.« less

Effect of mental stress on plasma homovanillic acid in healthy human subjects.

PubMed

Sumiyoshi, T; Yotsutsuji, T; Kurachi, M; Itoh, H; Kurokawa, K; Saitoh, O

1998-07-01

Plasma levels of homovanillic acid (pHVA) have been suggested to provide a measure of dopaminergic activity in the central nervous system. The present study investigated the effect of mental stress by the Kraepelin test, a test of continuous arithmetic addition of single-digit figures for 30 min, on pHVA levels in 13 male psychiatrically normal healthy volunteers. Following an overnight fast and restricted physical activity, plasma samples were collected immediately before and after the administration of the Kraepelin test. Plasma HVA levels following the administration of the Kraepelin test were significantly lower than the pretest pHVA levels. The percent change in pHVA levels by the Kraepelin test positively correlated with pretest pHVA levels. The observed reduction in pHVA levels by mental stress in normal subjects may reflect some aspects of a dopamine-dependent restitutive system in the brain.

Evaluation of Digital PCR as a Technique for Monitoring Acute Rejection in Kidney Transplantation.

PubMed

Lee, Hyeseon; Park, Young-Mi; We, Yu-Mee; Han, Duck Jong; Seo, Jung-Woo; Moon, Haena; Lee, Yu-Ho; Kim, Yang-Gyun; Moon, Ju-Young; Lee, Sang-Ho; Lee, Jong-Keuk

2017-03-01

Early detection and proper management of kidney rejection are crucial for the long-term health of a transplant recipient. Recipients are normally monitored by serum creatinine measurement and sometimes with graft biopsies. Donor-derived cell-free deoxyribonucleic acid (cfDNA) in the recipient's plasma and/or urine may be a better indicator of acute rejection. We evaluated digital PCR (dPCR) as a system for monitoring graft status using single nucleotide polymorphism (SNP)-based detection of donor DNA in plasma or urine. We compared the detection abilities of the QX200, RainDrop, and QuantStudio 3D dPCR systems. The QX200 was the most accurate and sensitive. Plasma and/or urine samples were isolated from 34 kidney recipients at multiple time points after transplantation, and analyzed by dPCR using the QX200. We found that donor DNA was almost undetectable in plasma DNA samples, whereas a high percentage of donor DNA was measured in urine DNA samples, indicating that urine is a good source of cfDNA for patient monitoring. We found that at least 24% of the highly polymorphic SNPs used to identify individuals could also identify donor cfDNA in transplant patient samples. Our results further showed that autosomal, sex-specific, and mitochondrial SNPs were suitable markers for identifying donor cfDNA. Finally, we found that donor-derived cfDNA measurement by dPCR was not sufficient to predict a patient's clinical condition. Our results indicate that donor-derived cfDNA is not an accurate predictor of kidney status in kidney transplant patients.

Preanalytical blood sample workup for cell-free DNA analysis using Droplet Digital PCR for future molecular cancer diagnostics.

PubMed

van Ginkel, Joost H; van den Broek, Daan A; van Kuik, Joyce; Linders, Dorothé; de Weger, Roel; Willems, Stefan M; Huibers, Manon M H

2017-10-01

In current molecular cancer diagnostics, using blood samples of cancer patients for the detection of genetic alterations in plasma (cell-free) circulating tumor DNA (ctDNA) is an emerging practice. Since ctDNA levels in blood are low, highly sensitive Droplet Digital PCR (ddPCR) can be used for detecting rare mutational targets. In order to perform ddPCR on blood samples, a standardized procedure for processing and analyzing blood samples is necessary to facilitate implementation into clinical practice. Therefore, we assessed the technical sample workup procedure for ddPCR on blood plasma samples. Blood samples from healthy individuals, as well as lung cancer patients were analyzed. We compared different methods and protocols for sample collection, storage, centrifugation, isolation, and quantification. Cell-free DNA (cfDNA) concentrations of several wild-type targets and BRAF and EGFR-mutant ctDNA concentrations quantified by ddPCR were primary outcome measurements. Highest cfDNA concentrations were measured in blood collected in serum tubes. No significant differences in cfDNA concentrations were detected between various time points of up to 24 h until centrifugation. Highest cfDNA concentrations were detected after DNA isolation with the Quick cfDNA Serum & Plasma Kit, while plasma isolation using the QIAamp Circulating Nucleic Acid Kit yielded the most consistent results. DdPCR results on cfDNA are highly dependent on multiple factors during preanalytical sample workup, which need to be addressed during the development of this diagnostic tool for cancer diagnostics in the future. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Analytical design of a parasitic-loading digital speed controller for a 400-hertz turbine driven alternator

NASA Technical Reports Server (NTRS)

Ingle, B. D.; Ryan, J. P.

1972-01-01

A design for a solid-state parasitic speed controller using digital logic was analyzed. Parasitic speed controllers are used in space power electrical generating systems to control the speed of turbine-driven alternators within specified limits. The analysis included the performance characteristics of the speed controller and the generation of timing functions. The speed controller using digital logic applies step loads to the alternator. The step loads conduct for a full half wave starting at either zero or 180 electrical degrees.

47 CFR 76.1909 - Redistribution control of unencrypted digital terrestrial broadcast content.

Code of Federal Regulations, 2011 CFR

2011-10-01

... content. Where a multichannel video programming distributor retransmits unencrypted digital terrestrial... 47 Telecommunication 4 2011-10-01 2011-10-01 false Redistribution control of unencrypted digital... (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Encoding Rules § 76.1909...

Sandia technology: Engineering and science applications

NASA Astrophysics Data System (ADS)

Maydew, M. C.; Parrot, H.; Dale, B. C.; Floyd, H. L.; Leonard, J. A.; Parrot, L.

1990-12-01

This report discusses: protecting environment, safety, and health; Sandia's quality initiative; Sandia vigorously pursues technology transfer; scientific and technical education support programs; nuclear weapons development; recognizing battlefield targets with trained artificial neural networks; battlefield robotics: warfare at a distance; a spinning shell sizes up the enemy; thwarting would-be nuclear terrorists; unattended video surveillance system for nuclear facilities; making the skies safer for travelers; onboard instrumentation system to evaluate performance of stockpile bombs; keeping track with lasers; extended-life lithium batteries; a remote digital video link acquires images securely; guiding high-performance missiles with laser gyroscopes; nonvolatile memory chips for space applications; initiating weapon explosives with lasers; next-generation optoelectronics and microelectronics technology developments; chemometrics: new methods for improving chemical analysis; research team focuses ion beam to record-breaking intensities; standardizing the volt to quantum accuracy; new techniques improve robotic software development productivity; a practical laser plasma source for generating soft x-rays; exploring metal grain boundaries; massively parallel computing; modeling the amount of desiccant needed for moisture control; attacking pollution with sunshine; designing fuel-conversion catalysts with computers; extending a nuclear power plant's useful life; plasma-facing components for the International Thermonuclear Experimental Reactor.

Instrument to synchronize Thomson scattering diagnostic measurements with MHD acitivity in a tokamak

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

Wintenberg, A.L.

1985-04-01

An instrument to synchronize the firing of a ruby laser for a Thomson scattering diagnostic with plasma oscillations was designed, developed, and evaluated. The instrument will fire the laser at a user-selected phase of an input sine or sawtooth wave with an accuracy of +-15/sup 0/. Allowable frequencies range from 20 to 500 Hz for a sawtooth and from 1 to 30 kHz for a sine wave. The instrument also allows synchronization with a sine wave to be enabled by a preselected sawtooth phase. The instrument uses analog signal processing circuits to separate the signal components, remove unwanted components, andmore » produce zero-phase synchronization pulses. The instrument measures the period between zero-phase pulses in order to produce phase synchronization pulses delayed a fraction of the period from the zero-phase pulses. The laser is fired by the phase synchronization pulse. Unwanted signal components are attenuated by bandpass filters. A digitally controlled self-adjusting bandpass filter for sine processing. The instrument was used to investigate the variation of the electron temperature profile with the phase of the x-ray signal from an Impurity Studies Experiment (ISX-B) plasma exhibiting magnetohydrodynamic (MHD) activity.« less

Synthetic Aperture Microwave Imaging (SAMI) of the plasma edge on NSTX-U

NASA Astrophysics Data System (ADS)

Vann, Roddy; Taylor, Gary; Brunner, Jakob; Ellis, Bob; Thomas, David

2016-10-01

The Synthetic Aperture Microwave Imaging (SAMI) system is a unique phased-array microwave camera with a +/-40° field of view in both directions. It can image cut-off surfaces corresponding to frequencies in the range 10-34.5GHz; these surfaces are typically in the plasma edge. SAMI operates in two modes: either imaging thermal emission from the plasma (often modified by its interaction with the plasma edge e.g. via BXO mode conversion) or ``active probing'' i.e. injecting a broad beam at the plasma surface and imaging the reflected/back-scattered signal. SAMI was successfully pioneered on the Mega-Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy. SAMI has now been installed and commissioned on the National Spherical Torus Experiment Upgrade (NSTX-U) at Princeton Plasma Physics Laboratory. The firmware has been upgraded to include real-time digital filtering, which enables continuous acquisition of the Doppler back-scattered active probing data. In this poster we shall present SAMI's analysis of the plasma edge on NSTX-U including measurements of the edge pitch angle on NSTX-U using SAMI's unique 2-D Doppler-backscattering capability.

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.

Access control based on attribute certificates for medical intranet applications.

PubMed

Mavridis, I; Georgiadis, C; Pangalos, G; Khair, M

2001-01-01

Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications. To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications. We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC. Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework. Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy.

Effects of aerobic exercise on mild cognitive impairment: a controlled trial.

PubMed

Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Cholerton, Brenna A; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

2010-01-01

To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Six-month, randomized, controlled, clinical trial. Veterans Affairs Puget Sound Health Care System clinical research unit. Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age, 70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and beta-amyloids 40 and 42. Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. This study provides support, using rigorous controlled methodology, for a potent nonpharmacologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise.

The research of laser marking control technology

NASA Astrophysics Data System (ADS)

Zhang, Qiue; Zhang, Rong

2009-08-01

In the area of Laser marking, the general control method is insert control card to computer's mother board, it can not support hot swap, it is difficult to assemble or it. Moreover, the one marking system must to equip one computer. In the system marking, the computer can not to do the other things except to transmit marking digital information. Otherwise it can affect marking precision. Based on traditional control methods existed some problems, introduced marking graphic editing and digital processing by the computer finish, high-speed digital signal processor (DSP) control marking the whole process. The laser marking controller is mainly contain DSP2812, digital memorizer, DAC (digital analog converting) transform unit circuit, USB interface control circuit, man-machine interface circuit, and other logic control circuit. Download the marking information which is processed by computer to U disk, DSP read the information by USB interface on time, then processing it, adopt the DSP inter timer control the marking time sequence, output the scanner control signal by D/A parts. Apply the technology can realize marking offline, thereby reduce the product cost, increase the product efficiency. The system have good effect in actual unit markings, the marking speed is more quickly than PCI control card to 20 percent. It has application value in practicality.

Optical demodulation system for digitally encoded suspension array in fluoroimmunoassay

NASA Astrophysics Data System (ADS)

He, Qinghua; Li, Dongmei; He, Yonghong; Guan, Tian; Zhang, Yilong; Shen, Zhiyuan; Chen, Xuejing; Liu, Siyu; Lu, Bangrong; Ji, Yanhong

2017-09-01

A laser-induced breakdown spectroscopy and fluorescence spectroscopy-coupled optical system is reported to demodulate digitally encoded suspension array in fluoroimmunoassay. It takes advantage of the plasma emissions of assembled elemental materials to digitally decode the suspension array, providing a more stable and accurate recognition to target biomolecules. By separating the decoding procedure of suspension array and adsorption quantity calculation of biomolecules into two independent channels, the cross talk between decoding and label signals in traditional methods had been successfully avoided, which promoted the accuracy of both processes and realized more sensitive quantitative detection of target biomolecules. We carried a multiplexed detection of several types of anti-IgG to verify the quantitative analysis performance of the system. A limit of detection of 1.48×10-10 M was achieved, demonstrating the detection sensitivity of the optical demodulation system.

Experience with synchronous and asynchronous digital control systems

NASA Technical Reports Server (NTRS)

Regenie, V. A.; Chacon, C. V.; Lock, W. P.

1986-01-01

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

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.

76 FR 78866 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-20

... initiated a rulemaking proceeding in accordance with provisions added by the Digital Millennium Copyright... available in digital copies. Proponent: The Open Book Alliance. 2. Literary works, distributed electronically, that: (1) Contain digital rights management and/or other access controls which either prevent the...

A scalable, self-analyzing digital locking system for use on quantum optics experiments.

PubMed

Sparkes, B M; Chrzanowski, H M; Parrain, D P; Buchler, B C; Lam, P K; Symul, T

2011-07-01

Digital control of optics experiments has many advantages over analog control systems, specifically in terms of the scalability, cost, flexibility, and the integration of system information into one location. We present a digital control system, freely available for download online, specifically designed for quantum optics experiments that allows for automatic and sequential re-locking of optical components. We show how the inbuilt locking analysis tools, including a white-noise network analyzer, can be used to help optimize individual locks, and verify the long term stability of the digital system. Finally, we present an example of the benefits of digital locking for quantum optics by applying the code to a specific experiment used to characterize optical Schrödinger cat states.

Real-time simulation of the TF30-P-3 turbofan engine using a hybrid computer

NASA Technical Reports Server (NTRS)

Szuch, J. R.; Bruton, W. M.

1974-01-01

A real-time, hybrid-computer simulation of the TF30-P-3 turbofan engine was developed. The simulation was primarily analog in nature but used the digital portion of the hybrid computer to perform bivariate function generation associated with the performance of the engine's rotating components. FORTRAN listings and analog patching diagrams are provided. The hybrid simulation was controlled by a digital computer programmed to simulate the engine's standard hydromechanical control. Both steady-state and dynamic data obtained from the digitally controlled engine simulation are presented. Hybrid simulation data are compared with data obtained from a digital simulation provided by the engine manufacturer. The comparisons indicate that the real-time hybrid simulation adequately matches the baseline digital simulation.

Characterization of a 16-Bit Digitizer for Lidar Data Acquisition

NASA Technical Reports Server (NTRS)

Williamson, Cynthia K.; DeYoung, Russell J.

2000-01-01

A 6-MHz 16-bit waveform digitizer was evaluated for use in atmospheric differential absorption lidar (DIAL) measurements of ozone. The digitizer noise characteristics were evaluated, and actual ozone DIAL atmospheric returns were digitized. This digitizer could replace computer-automated measurement and control (CAMAC)-based commercial digitizers and improve voltage accuracy.

76 FR 34276 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-13

... Subcommittee on Digital Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital... briefing on the results and status of new NRC nuclear power plant digital system research activities which deal with Inventory and Certification of digital systems, operating experience for digital systems, and...

Design Method of Digital Optimal Control Scheme and Multiple Paralleled Bridge Type Current Amplifier for Generating Gradient Magnetic Fields in MRI Systems

NASA Astrophysics Data System (ADS)

Watanabe, Shuji; Takano, Hiroshi; Fukuda, Hiroya; Hiraki, Eiji; Nakaoka, Mutsuo

This paper deals with a digital control scheme of multiple paralleled high frequency switching current amplifier with four-quadrant chopper for generating gradient magnetic fields in MRI (Magnetic Resonance Imaging) systems. In order to track high precise current pattern in Gradient Coils (GC), the proposal current amplifier cancels the switching current ripples in GC with each other and designed optimum switching gate pulse patterns without influences of the large filter current ripple amplitude. The optimal control implementation and the linear control theory in GC current amplifiers have affinity to each other with excellent characteristics. The digital control system can be realized easily through the digital control implementation, DSPs or microprocessors. Multiple-parallel operational microprocessors realize two or higher paralleled GC current pattern tracking amplifier with optimal control design and excellent results are given for improving the image quality of MRI systems.

Development and flight test experiences with a flight-crucial digital control system

NASA Technical Reports Server (NTRS)

Mackall, Dale A.

1988-01-01

Engineers and scientists in the advanced fighter technology integration (AFTI) F-16 program investigated the integration of emerging technologies into an advanced fighter aircraft. AFTI's three major technologies included: flight-crucial digital control, decoupled aircraft flight control, and integration of avionics, flight control, and pilot displays. In addition to investigating improvements in fighter performance, researchers studied the generic problems confronting the designers of highly integrated flight-crucial digital control. An overview is provided of both the advantages and problems of integration digital control systems. Also, an examination of the specification, design, qualification, and flight test life-cycle phase is provided. An overview is given of the fault-tolerant design, multimoded decoupled flight control laws, and integrated avionics design. The approach to qualifying the software and system designs is discussed, and the effects of design choices on system qualification are highlighted.

NASA researchers in gold control room during an F-15 HiDEC flight

NASA Technical Reports Server (NTRS)

1993-01-01

NASA researchers monitor equipment in the mission control Gold room at the Dryden Flight Research Center, Edwards, California, during a flight of an F-15 Highly Integrated Digital Electronic Control (HIDEC) research aircraft. The system was developed on the F-15 to investigate and demonstrate methods of obtaining optimum aircraft performance. The major elements of HIDEC were a Digital Electronic Flight Control System (DEFCS), a Digital Electronic Engine Control (DEEC), an on-board general purpose computer, and an integrated architecture to allow all components to 'talk to each other.' Unlike standard F-15s, which have a mechanical and analog electronic flight control system, the HIDEC F-15 also had a dual-channel, fail-safe digital flight control system programmed in Pascal. It was linked to the Military Standard 1553B and a H009 data bus which tied all the other electronic systems together.

Demonstrative fractional order - PID controller based DC motor drive on digital platform.

PubMed

Khubalkar, Swapnil W; Junghare, Anjali S; Aware, Mohan V; Chopade, Amit S; Das, Shantanu

2017-09-21

In industrial drives applications, fractional order controllers can exhibit phenomenal impact due to realization through digital implementation. Digital fractional order controllers have created wide scope as it possess the inherent advantages like robustness against the plant parameter variation. This paper provides brief design procedure of fractional order proportional-integral-derivative (FO-PID) controller through the indirect approach of approximation using constant phase technique. The new modified dynamic particle swarm optimization (IdPSO) technique is proposed to find controller parameters. The FO-PID controller is implemented using floating point digital signal processor. The building blocks are designed and assembled with all peripheral components for the 1.5kW industrial DC motor drive. The robust operation for parametric variation is ascertained by testing the controller with two separately excited DC motors with the same rating but different parameters. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

NASA researchers in gold control room during an F-15 HiDEC flight, John Orme and Gerard Schkolnik

NASA Technical Reports Server (NTRS)

1993-01-01

NASA researchers Gerard Schkolnik (left) and John Orme monitor equipment in the control room at the Dryden Flight Research Center, Edwards, California, during a flight of an F-15 Highly Integrated Digital Electronic Control (HIDEC) research aircraft. The system was developed on the F-15 to investigate and demonstrate methods of obtaining optimum aircraft performance. The major elements of HIDEC were a Digital Electronic Flight Control System (DEFCS), a Digital Electronic Engine Control (DEEC), an on-board general purpose computer, and an integrated architecture to allow all components to 'talk to each other.' Unlike standard F-15s, which have a mechanical and analog electronic flight control system, the HIDEC F-15 also had a dual-channel, fail-safe digital flight control system programmed in Pascal. It was linked to the Military Standard 1553B and a H009 data bus which tied all the other electronic systems together.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted into digital signals and transmitted back to the controller. In one embodiment, the bus controller sends commands and data a defined bit rate, and the network device interface senses this bit rate and sends data back to the bus controller using the defined bit rate.

YADCLAN: yet another digitally-controlled linear artificial neuron.

PubMed

Frenger, Paul

2003-01-01

This paper updates the author's 1999 RMBS presentation on digitally controlled linear artificial neuron design. Each neuron is based on a standard operational amplifier having excitatory and inhibitory inputs, variable gain, an amplified linear analog output and an adjustable threshold comparator for digital output. This design employs a 1-wire serial network of digitally controlled potentiometers and resistors whose resistance values are set and read back under microprocessor supervision. This system embodies several unique and useful features, including: enhanced neuronal stability, dynamic reconfigurability and network extensibility. This artificial neuronal is being employed for feature extraction and pattern recognition in an advanced robotic application.

The design of digital-adaptive controllers for VTOL aircraft

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Broussard, J. R.; Berry, P. W.

1976-01-01

Design procedures for VTOL automatic control systems have been developed and are presented. Using linear-optimal estimation and control techniques as a starting point, digital-adaptive control laws have been designed for the VALT Research Aircraft, a tandem-rotor helicopter which is equipped for fully automatic flight in terminal area operations. These control laws are designed to interface with velocity-command and attitude-command guidance logic, which could be used in short-haul VTOL operations. Developments reported here include new algorithms for designing non-zero-set-point digital regulators, design procedures for rate-limited systems, and algorithms for dynamic control trim setting.

Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane

NASA Technical Reports Server (NTRS)

1984-01-01

Flight evaluation in an F-15 aircraft by digital electronic engine control (DEEC) was investigated. Topics discussed include: system description, F100 engine tests, effects of inlet distortion on static pressure probe, flight tests, digital electronic engine control fault detection and accommodation flight evaluation, flight evaluation of a hydromechanical backup control, augmentor transient capability of an F100 engine, investigation of nozzle instability, real time in flight thrust calculation, and control technology for future aircraft propulsion systems. It is shown that the DEEC system is a powerful and flexible controller for the F100 engine.

Experimental validation of a Lyapunov-based controller for the plasma safety factor and plasma pressure in the TCV tokamak

NASA Astrophysics Data System (ADS)

Mavkov, B.; Witrant, E.; Prieur, C.; Maljaars, E.; Felici, F.; Sauter, O.; the TCV-Team

2018-05-01

In this paper, model-based closed-loop algorithms are derived for distributed control of the inverse of the safety factor profile and the plasma pressure parameter β of the TCV tokamak. The simultaneous control of the two plasma quantities is performed by combining two different control methods. The control design of the plasma safety factor is based on an infinite-dimensional setting using Lyapunov analysis for partial differential equations, while the control of the plasma pressure parameter is designed using control techniques for single-input and single-output systems. The performance and robustness of the proposed controller is analyzed in simulations using the fast plasma transport simulator RAPTOR. The control is then implemented and tested in experiments in TCV L-mode discharges using the RAPTOR model predicted estimates for the q-profile. The distributed control in TCV is performed using one co-current and one counter-current electron cyclotron heating actuation.

Digital control of highly augmented combat rotorcraft

NASA Technical Reports Server (NTRS)

Tischler, Mark B.

1987-01-01

Proposed concepts for the next generation of combat helicopters are to be embodied in a complex, highly maneuverable, multiroled vehicle with avionics systems. Single pilot and nap-of-the-Earth operations require handling qualities which minimize the involvement of the pilot in basic stabilization tasks. To meet these requirements will demand a full authority, high-gain, multimode, multiply-redundant, digital flight-control system. The gap between these requirements and current low-authority, low-bandwidth operational rotorcraft flight-control technology is considerable. This research aims at smoothing the transition between current technology and advanced concept requirements. The state of the art of high-bandwidth digital flight-control systems are reviewed; areas of specific concern for flight-control systems of modern combat are exposed; and the important concepts are illustrated in design and analysis of high-gain, digital systems with a detailed case study involving a current rotorcraft system. Approximate and exact methods are explained and illustrated for treating the important concerns which are unique to digital systems.

MAS2-8 radar and digital control unit

NASA Technical Reports Server (NTRS)

Oberg, J. M.; Ulaby, F. T.

1974-01-01

The design of the MAS 2-8 (2 to 8 GHz microwave-active spectrometer), a ground-based sensor system, is presented. A major modification in 1974 to the MAS 2-8, that of a control subsystem to automate the data-taking operation, is the prime focus. The digital control unit automatically changes all system parameters except FM rate and records the return signal on paper tape. The overall system operation and a detailed discussion of the design and operation of the digital control unit are presented.

Evaluation of Digital Checklists for Command and Control Operations

DTIC Science & Technology

2016-01-01

EVALUATION OF DIGITAL CHECKLISTS FOR COMMAND AND CONTROL OPERATIONS Christopher K. McClernon 1 , Victor S. Finomore 2 , Terence S. Andre 3...the potential effectiveness of a digital system that could take the place of the paper system that is currently being used. A between groups...assessments of each system were analyzed and compared. The data showed that a linear digital checklist takes a longer amount of time than both a paper

Automatic weld torch guidance control system

NASA Technical Reports Server (NTRS)

Smaith, H. E.; Wall, W. A.; Burns, M. R., Jr.

1982-01-01

A highly reliable, fully digital, closed circuit television optical, type automatic weld seam tracking control system was developed. This automatic tracking equipment is used to reduce weld tooling costs and increase overall automatic welding reliability. The system utilizes a charge injection device digital camera which as 60,512 inidividual pixels as the light sensing elements. Through conventional scanning means, each pixel in the focal plane is sequentially scanned, the light level signal digitized, and an 8-bit word transmitted to scratch pad memory. From memory, the microprocessor performs an analysis of the digital signal and computes the tracking error. Lastly, the corrective signal is transmitted to a cross seam actuator digital drive motor controller to complete the closed loop, feedback, tracking system. This weld seam tracking control system is capable of a tracking accuracy of + or - 0.2 mm, or better. As configured, the system is applicable to square butt, V-groove, and lap joint weldments.

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

F-8 Iron Bird Cockpit

NASA Technical Reports Server (NTRS)

1975-01-01

The F-8 DFBW (Digital-Fly-By-Wire) simulator used an 'Iron-Bird' for its cockpit. It was used from 1971 to 1986. The F-8 DFBW simulator was used in the development, testing, and validation of an all digital flight-control system installed in the F-8 aircraft that replaced the normal mechanical/hydraulic controls. Many military and commercial aircraft have digital flight control systems based on the technologies developed at NASA Dryden.

Digital control system for space structure dampers

NASA Technical Reports Server (NTRS)

Haviland, J. K.

1985-01-01

A digital controller was developed using an SKD-51 System Design Kit, which incorporates an 8031 microcontroller. The necessary interfaces were installed in the wire wrap area of the SKD-51 and a pulse width modulator was developed to drive the coil of the actuator. Also, control equations were developed, using floating-point arithmetic. The design of the digital control system is emphasized, and it is shown that, provided certain rules are followed, an adequate design can be achieved. It is recommended that the so-called w-plane design method be used, and that the time elapsed before output of the up-dated coil-force signal be kept as small as possible. However, the cycle time for the controller should be watched carefully, because very small values for this time can lead to digital noise.

Flight evaluation of a digital electronic engine control system in an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.; Mackall, K. G.; Burcham, F. W., Jr.; Walter, W. A.

1982-01-01

Benefits provided by a full-authority digital engine control are related to improvements in engine efficiency, performance, and operations. An additional benefit is the capability of detecting and accommodating failures in real time and providing engine-health diagnostics. The digital electronic engine control (DEEC), is a full-authority digital engine control developed for the F100-PW-100 turbofan engine. The DEEC has been flight tested on an F-15 aircraft. The flight tests had the objective to evaluate the DEEC hardware and software over the F-15 flight envelope. A description is presented of the results of the flight tests, which consisted of nonaugmented and augmented throttle transients, airstarts, and backup control operations. The aircraft, engine, DEEC system, and data acquisition and reduction system are discussed.

Profile control simulations and experiments on TCV: a controller test environment and results using a model-based predictive controller

NASA Astrophysics Data System (ADS)

Maljaars, E.; Felici, F.; Blanken, T. C.; Galperti, C.; Sauter, O.; de Baar, M. R.; Carpanese, F.; Goodman, T. P.; Kim, D.; Kim, S. H.; Kong, M.; Mavkov, B.; Merle, A.; Moret, J. M.; Nouailletas, R.; Scheffer, M.; Teplukhina, A. A.; Vu, N. M. T.; The EUROfusion MST1-team; The TCV-team

2017-12-01

The successful performance of a model predictive profile controller is demonstrated in simulations and experiments on the TCV tokamak, employing a profile controller test environment. Stable high-performance tokamak operation in hybrid and advanced plasma scenarios requires control over the safety factor profile (q-profile) and kinetic plasma parameters such as the plasma beta. This demands to establish reliable profile control routines in presently operational tokamaks. We present a model predictive profile controller that controls the q-profile and plasma beta using power requests to two clusters of gyrotrons and the plasma current request. The performance of the controller is analyzed in both simulation and TCV L-mode discharges where successful tracking of the estimated inverse q-profile as well as plasma beta is demonstrated under uncertain plasma conditions and the presence of disturbances. The controller exploits the knowledge of the time-varying actuator limits in the actuator input calculation itself such that fast transitions between targets are achieved without overshoot. A software environment is employed to prepare and test this and three other profile controllers in parallel in simulations and experiments on TCV. This set of tools includes the rapid plasma transport simulator RAPTOR and various algorithms to reconstruct the plasma equilibrium and plasma profiles by merging the available measurements with model-based predictions. In this work the estimated q-profile is merely based on RAPTOR model predictions due to the absence of internal current density measurements in TCV. These results encourage to further exploit model predictive profile control in experiments on TCV and other (future) tokamaks.

Design description of a microprocessor based Engine Monitoring and Control unit (EMAC) for small turboshaft

NASA Technical Reports Server (NTRS)

Baez, A. N.

1985-01-01

Research programs have demonstrated that digital electronic controls are more suitable for advanced aircraft/rotorcraft turbine engine systems than hydromechanical controls. Commercially available microprocessors are believed to have the speed and computational capability required for implementing advanced digital control algorithms. Thus, it is desirable to demonstrate that off-the-shelf microprocessors are indeed capable of performing real time control of advanced gas turbine engines. The engine monitoring and control (EMAC) unit was designed and fabricated specifically to meet the requirements of an advanced gas turbine engine control system. The EMAC unit is fully operational in the Army/NASA small turboshaft engine digital research program.

Experimental investigation of the effect of insulator sleeve length on the time to pinch and multipinch formation in the plasma focus facility

NASA Astrophysics Data System (ADS)

Momenei, M.; Khodabakhshei, Z.; Panahi, N.; Mohammadi, M. A.

2017-03-01

The length of insulator sleeve is varied to investigate its effect on the pinch formation in the plasma focus facility. In this paper, the effect of insulator length on the time to pinch at various pressures and working voltages in the 1.15 kJ Mather type plasma focus is investigated. The results show that with 4.5 cm insulator length the time to pinch at all pressures is minimum. Other results also confirm that with increasing of pressure the time to pinch is increased. Moreover, with increasing working voltage the time to pinch is decreased. Pictures, captured using a digital single lens reflex (DSLR) Canon EOS 7D system, show that multipinch phenomenon is formed.

Optical modulation techniques for analog signal processing and CMOS compatible electro-optic modulation

NASA Astrophysics Data System (ADS)

Gill, Douglas M.; Rasras, Mahmoud; Tu, Kun-Yii; Chen, Young-Kai; White, Alice E.; Patel, Sanjay S.; Carothers, Daniel; Pomerene, Andrew; Kamocsai, Robert; Beattie, James; Kopa, Anthony; Apsel, Alyssa; Beals, Mark; Mitchel, Jurgen; Liu, Jifeng; Kimerling, Lionel C.

2008-02-01

Integrating electronic and photonic functions onto a single silicon-based chip using techniques compatible with mass-production CMOS electronics will enable new design paradigms for existing system architectures and open new opportunities for electro-optic applications with the potential to dramatically change the management, cost, footprint, weight, and power consumption of today's communication systems. While broadband analog system applications represent a smaller volume market than that for digital data transmission, there are significant deployments of analog electro-optic systems for commercial and military applications. Broadband linear modulation is a critical building block in optical analog signal processing and also could have significant applications in digital communication systems. Recently, broadband electro-optic modulators on a silicon platform have been demonstrated based on the plasma dispersion effect. The use of the plasma dispersion effect within a CMOS compatible waveguide creates new challenges and opportunities for analog signal processing since the index and propagation loss change within the waveguide during modulation. We will review the current status of silicon-based electrooptic modulators and also linearization techniques for optical modulation.

The erythrocyte sodium and potassium in patients treated with digoxin.

PubMed Central

Morgan, D B; Cumberbatch, M; Cohn, S; Scott, D; Gunasuntharam, T; Davidson, C; Chapman, C

1980-01-01

1 Four healthy persons and ten patients with heart failure were studied for 5 to 20 days after they started taking digoxin. The sodium content of their erythrocytes increased and there was an equimolar decrease in potassium content. 2 The increase in erythrocyte sodium for a given increase in plasma digoxin during this acute digitalization was less on average and varied more in the patients than in the healthy persons, that is the patients' erythrocytes were less responsive to digoxin. 3 The average erythrocyte sodium was greater in 183 patients who had been taking digoxin for at least 2 months than in 100 healthy persons not taking digoxin but there was no significant correlation between the plasma digoxin concentrations and erythrocyte sodium concentration in the patients. Indeed, there was no apparent change in the erythrocyte sodium in many of the patients taking digoxin. 4 If the erythrocyte sodium concentration is a reliable guide to the tissue effects of digoxin then the results suggest that there is a wide variation in the response to digoxin between patients both during acute digitalization and during chronic treatment with digoxin. PMID:7426274

Research of Fast DAQ system in KSTAR Thomson scattering diagnostic

NASA Astrophysics Data System (ADS)

Lee, J. H.; Kim, H. J.; Yamada, I.; Funaba, H.; Kim, Y. G.; Kim, D. Y.

2017-12-01

The Thomson scattering diagnostic is one of the most important diagnostic systems in fusion plasma research. It provides reliable electron temperature and density profiles in magnetically confined plasma. A Q-switched Nd:YAG Thomson system was installed several years ago in KSTAR tokamak to measure the electron temperature and density profiles. For the KSTAR Thomson scattering system, a Charge-to-Digital Conversion (QDC) type data acquisition system was used to measure a pulse type Thomson signal. Recently, however, an error was found during the Te, ne calculation, because the QDC system had integrated the pulse Thomson signal that included a signal similar to stray light. To overcome such errors, we introduce a fast data acquisition (F-DAQ) system. To test this, we use CAEN V1742 5 GS/s, a Versa Module Eurocard Bus (VMEbus) type 12-bit switched capacitor digitizer with 32 channels. In this experiment, we compare the calculated Te results of Thomson scattering data measured simultaneously using QDC and F-DAQ. In the F-DAQ system, the shape of the pulse was restored by fitting.

Acyl guanidine inhibitors of β-secretase (BACE-1): optimization of a micromolar hit to a nanomolar lead via iterative solid- and solution-phase library synthesis.

PubMed

Gerritz, Samuel W; Zhai, Weixu; Shi, Shuhao; Zhu, Shirong; Toyn, Jeremy H; Meredith, Jere E; Iben, Lawrence G; Burton, Catherine R; Albright, Charles F; Good, Andrew C; Tebben, Andrew J; Muckelbauer, Jodi K; Camac, Daniel M; Metzler, William; Cook, Lynda S; Padmanabha, Ramesh; Lentz, Kimberley A; Sofia, Michael J; Poss, Michael A; Macor, John E; Thompson, Lorin A

2012-11-08

This report describes the discovery and optimization of a BACE-1 inhibitor series containing an unusual acyl guanidine chemotype that was originally synthesized as part of a 6041-membered solid-phase library. The synthesis of multiple follow-up solid- and solution-phase libraries facilitated the optimization of the original micromolar hit into a single-digit nanomolar BACE-1 inhibitor in both radioligand binding and cell-based functional assay formats. The X-ray structure of representative inhibitors bound to BACE-1 revealed a number of key ligand:protein interactions, including a hydrogen bond between the side chain amide of flap residue Gln73 and the acyl guanidine carbonyl group, and a cation-π interaction between Arg235 and the isothiazole 4-methoxyphenyl substituent. Following subcutaneous administration in rats, an acyl guanidine inhibitor with single-digit nanomolar activity in cells afforded good plasma exposures and a dose-dependent reduction in plasma Aβ levels, but poor brain exposure was observed (likely due to Pgp-mediated efflux), and significant reductions in brain Aβ levels were not obtained.

Improving Hypertension Control and Patient Engagement Using Digital Tools.

PubMed

Milani, Richard V; Lavie, Carl J; Bober, Robert M; Milani, Alexander R; Ventura, Hector O

2017-01-01

Hypertension is present in 30% of the adult US population and is a major contributor to cardiovascular disease. The established office-based approach yields only 50% blood pressure control rates and low levels of patient engagement. Available home technology now provides accurate, reliable data that can be transmitted directly to the electronic medical record. We evaluated blood pressure control in 156 patients with uncontrolled hypertension enrolled into a home-based digital-medicine blood pressure program and compared them with 400 patients (matched to age, sex, body mass index, and blood pressure) in a usual-care group after 90 days. Digital-medicine patients completed questionnaires online, were asked to submit at least one blood pressure reading/week, and received medication management and lifestyle recommendations via a clinical pharmacist and a health coach. Blood pressure units were commercially available that transmitted data directly to the electronic medical record. Digital-medicine patients averaged 4.2 blood pressure readings per week. At 90 days, 71% of digital-medicine vs 31% of usual-care patients had achieved target blood pressure control. Mean decrease in systolic/diastolic blood pressure was 14/5 mm Hg in digital medicine, vs 4/2 mm Hg in usual care (P < .001). Excess sodium consumption decreased from 32% to 8% in the digital-medicine group (P = .004). Mean patient activation increased from 41.9 to 44.1 (P = .008), and the percentage of patients with low patient activation decreased from 15% to 6% (P = .03) in the digital-medicine group. A digital hypertension program is feasible and associated with significant improvement in blood pressure control rates and lifestyle change. Utilization of a virtual health intervention using connected devices improves patient activation and is well accepted by patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Microprocessor Based Temperature Control of Liquid Delivery with Flow Disturbances.

ERIC Educational Resources Information Center

Kaya, Azmi

1982-01-01

Discusses analytical design and experimental verification of a PID control value for a temperature controlled liquid delivery system, demonstrating that the analytical design techniques can be experimentally verified by using digital controls as a tool. Digital control instrumentation and implementation are also demonstrated and documented for…

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.

Digital Morphometrics: A New Upper Airway Phenotyping Paradigm in OSA.

PubMed

Schwab, Richard J; Leinwand, Sarah E; Bearn, Cary B; Maislin, Greg; Rao, Ramya Bhat; Nagaraja, Adithya; Wang, Stephen; Keenan, Brendan T

2017-08-01

OSA is associated with changes in pharyngeal anatomy. The goal of this study was to objectively and reproducibly quantify pharyngeal anatomy by using digital morphometrics based on a laser ruler and to assess differences between subjects with OSA and control subjects and associations with the apnea-hypopnea index (AHI). To the best of our knowledge, this study is the first to use digital morphometrics to quantify intraoral risk factors for OSA. Digital photographs were obtained by using an intraoral laser ruler and digital camera in 318 control subjects (mean AHI, 4.2 events/hour) and 542 subjects with OSA (mean AHI, 39.2 events/hour). The digital morphometric paradigm was validated and reproducible over time and camera distances. A larger modified Mallampati score and having a nonvisible airway were associated with a higher AHI, both unadjusted (P < .001) and controlling for age, sex, race, and BMI (P = .015 and P = .018, respectively). Measures of tongue size were larger in subjects with OSA vs control subjects in unadjusted models and controlling for age, sex, and race but nonsignificant controlling for BMI; similar results were observed with AHI severity. Multivariate regression suggests photography-based variables capture independent associations with OSA. Measures of tongue size, airway visibility, and Mallampati scores were associated with increased OSA risk and severity. This study shows that digital morphometrics is an accurate, high-throughput, and noninvasive technique to identify anatomic OSA risk factors. Morphometrics may also provide a more reproducible and standardized measurement of the Mallampati score. Digital morphometrics represent an efficient and cost-effective method of examining intraoral crowding and tongue size when examining large populations, genetics, or screening for OSA. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Learner-Controlled Scaffolding Linked to Open-Ended Problems in a Digital Learning Environment

ERIC Educational Resources Information Center

Edson, Alden Jack

2017-01-01

This exploratory study reports on how students activated learner-controlled scaffolding and navigated through sequences of connected problems in a digital learning environment. A design experiment was completed to (re)design, iteratively develop, test, and evaluate a digital version of an instructional unit focusing on binomial distributions and…

Imaging photomultiplier array with integrated amplifiers and high-speed USB interfacea)

NASA Astrophysics Data System (ADS)

Blacksell, M.; Wach, J.; Anderson, D.; Howard, J.; Collis, S. M.; Blackwell, B. D.; Andruczyk, D.; James, B. W.

2008-10-01

Multianode photomultiplier tube (PMT) arrays are finding application as convenient high-speed light sensitive devices for plasma imaging. This paper describes the development of a USB-based "plug-n-play" 16-channel PMT camera with 16bits simultaneous acquisition of 16 signal channels at rates up to 2MS/s per channel. The preamplifiers and digital hardware are packaged in a compact housing which incorporates magnetic shielding, on-board generation of the high-voltage PMT bias, an optical filter mount and slits, and F-mount lens adaptor. Triggering, timing, and acquisition are handled by four field-programmable gate arrays (FPGAs) under instruction from a master FPGA controlled by a computer with a LABVIEW interface. We present technical design details and specifications and illustrate performance with high-speed images obtained on the H-1 heliac at the ANU.

Imaging photomultiplier array with integrated amplifiers and high-speed USB interface.

PubMed

Blacksell, M; Wach, J; Anderson, D; Howard, J; Collis, S M; Blackwell, B D; Andruczyk, D; James, B W

2008-10-01

Multianode photomultiplier tube (PMT) arrays are finding application as convenient high-speed light sensitive devices for plasma imaging. This paper describes the development of a USB-based "plug-n-play" 16-channel PMT camera with 16 bits simultaneous acquisition of 16 signal channels at rates up to 2 MSs per channel. The preamplifiers and digital hardware are packaged in a compact housing which incorporates magnetic shielding, on-board generation of the high-voltage PMT bias, an optical filter mount and slits, and F-mount lens adaptor. Triggering, timing, and acquisition are handled by four field-programmable gate arrays (FPGAs) under instruction from a master FPGA controlled by a computer with a LABVIEW interface. We present technical design details and specifications and illustrate performance with high-speed images obtained on the H-1 heliac at the ANU.

Access Control based on Attribute Certificates for Medical Intranet Applications

PubMed Central

Georgiadis, Christos; Pangalos, George; Khair, Marie

2001-01-01

Background Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications. Objectives To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications. Methods We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC. Results Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework. Conclusions Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy. PMID:11720951

Self-tuning control of attitude and momentum management for the Space Station

NASA Technical Reports Server (NTRS)

Shieh, L. S.; Sunkel, J. W.; Yuan, Z. Z.; Zhao, X. M.

1992-01-01

This paper presents a hybrid state-space self-tuning design methodology using dual-rate sampling for suboptimal digital adaptive control of attitude and momentum management for the Space Station. This new hybrid adaptive control scheme combines an on-line recursive estimation algorithm for indirectly identifying the parameters of a continuous-time system from the available fast-rate sampled data of the inputs and states and a controller synthesis algorithm for indirectly finding the slow-rate suboptimal digital controller from the designed optimal analog controller. The proposed method enables the development of digitally implementable control algorithms for the robust control of Space Station Freedom with unknown environmental disturbances and slowly time-varying dynamics.

Numerical study on the selective excitation of Helmholtz-Gauss beams in end-pumped solid-state digital lasers with the control of the laser gain transverse position provided by off-axis end pumping

NASA Astrophysics Data System (ADS)

Tsai, Ko-Fan; Chu, Shu-Chun

2018-03-01

This study proposes a complete and unified method for selective excitation of any specified nearly nondiffracting Helmholtz-Gauss (HzG) beam in end-pumped solid-state digital lasers. Four types of the HzG beams: cosine-Gauss beams, Bessel-Gauss beams, Mathieu-Gauss beams, and, in particular, parabolic-Gauss beams are successfully demonstrated to be generated with the proposed methods. To the best of the authors’ knowledge, parabolic-Gauss beams have not yet been directly generated from any kind of laser system. The numerical results of this study show that one can successfully achieve any lasing HzG beams directly from the solid-state digital lasers with only added control of the laser gain transverse position provided by off-axis end pumping. This study also presents a practical digital laser set-up for easily manipulating off-axis pumping in order to achieve the control of the laser gain transverse gain position in digital lasers. The reported results in this study provide advancement of digital lasers in dynamically generating nondiffracting beams. The control of the digital laser cavity gain position creates the possibility of achieving real-time selection of more laser modes in digital lasers, and it is worth further investigation in the future.

Real Time Digital Control of a Magnetostrictive Actuator

NASA Technical Reports Server (NTRS)

Zrostlik, Rick L.; Hall, David L.; Flatau, Alison B.

1996-01-01

The use of the magnetostrictive material Terfenol-D as a motion source in active vibration control (AVC) systems are being studied. Currently it is of limited use due to the nonlinear nature of the strain versus magnetization curve and the magnetic hysteresis in the Terfenol-D. One manifestation of these nonlinearities is waveform distortion in the output velocity of the transducer. For Terfenol-D to be used in ever greater numbers of AVC systems, these nonlinearities must be addressed. In this study the nonlinearities are treated as disturbances to a linear system. The acceleration output is used in simple analog and digital feedback control schemes to improve linearity of the transducer. In addition, the use of a Terfenol-D actuator in an AVC system is verified. Both analog and digital controllers are implemented and results compared. A cantilever beam system is considered for AVC applications. The second thrust of this presentation is the reduction of harmonic distortions. Two conclusions can be reached from this work. One, the linearization of Terfenol-D transducers is possible with the use of feedback controllers, both digital and analog. Second, Terfenol-D is a viable motion source in active vibration control systems utilizing either analog or digital controllers.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor)

2007-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. In some embodiments, network device interfaces associated with different data channels coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor); Konz, Daniel W. (Inventor)

2009-01-01

A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface is a state machine, such as an ASIC, that operates independent of a processor in communicating with the bus controller and data channels.

Converting the Active Digital Controller for Use in Two Tests

NASA Technical Reports Server (NTRS)

Wright, Robert G.

1995-01-01

The Active Digital Controller is a system used to control the various functions of wind tunnel models. It has the capability of digitizing and saving of up to sixty-four channels of analog data. It can output up to 16 channels of analog command signals. In addition to its use as a general controller, it can run up to two distinct control laws. All of this is done at a regulated speed of two hundred hertz. The Active Digital Controller (ADC) was modified for use in the Actively Controlled Response of Buffet Affected Tails (ACROBAT) tests and for side-wall pressure data acquisition. The changes included general maintenance and updating of the controller as well as setting up special modes of operation. The ACROBAT tests required that two sets of output signals be available. The pressure data acquisition needed a sampling rate of four hundred hertz, twice the standard ADC rate. These modifications were carried out and the ADC was used during the ACROBAT wind tunnel entry.

Precision digital pulse phase generator

DOEpatents

McEwan, T.E.

1996-10-08

A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code. 2 figs.

Precision digital pulse phase generator

DOEpatents

McEwan, Thomas E.

1996-01-01

A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code.

Digital intelligent booster for DCC miniature train networks

NASA Astrophysics Data System (ADS)

Ursu, M. P.; Condruz, D. A.

2017-08-01

Modern miniature trains are now driven by means of the DCC (Digital Command and Control) system, which allows the human operator or a personal computer to launch commands to each individual train or even to control different features of the same train. The digital command station encodes these commands and sends them to the trains by means of electrical pulses via the rails of the railway network. Due to the development of the miniature railway network, it may happen that the power requirement of the increasing number of digital locomotives, carriages and accessories exceeds the nominal output power of the digital command station. This digital intelligent booster relieves the digital command station from powering the entire railway network all by itself, and it automatically handles the multiple powered sections of the network. This electronic device is also able to detect and process short-circuits and overload conditions, without the intervention of the digital command station.

A survey of digital radiography practice in four South African teaching hospitals: an illuminative study.

PubMed

Nyathi, T; Chirwa, Tf; van der Merwe, Dg

2010-01-01

The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography. A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software. Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography. The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital radiography being undertaken as such there is need for formal education, continuing education and manufacturer training with respect to quality control as institutions make the transition from conventional screen film radiology to digital radiology.

Systems and methods for self-synchronized digital sampling

NASA Technical Reports Server (NTRS)

Samson, Jr., John R. (Inventor)

2008-01-01

Systems and methods for self-synchronized data sampling are provided. In one embodiment, a system for capturing synchronous data samples is provided. The system includes an analog to digital converter adapted to capture signals from one or more sensors and convert the signals into a stream of digital data samples at a sampling frequency determined by a sampling control signal; and a synchronizer coupled to the analog to digital converter and adapted to receive a rotational frequency signal from a rotating machine, wherein the synchronizer is further adapted to generate the sampling control signal, and wherein the sampling control signal is based on the rotational frequency signal.

Detection and prognostic value of recurrent exportin 1 mutations in tumor and cell-free circulating DNA of patients with classical Hodgkin lymphoma.

PubMed

Camus, Vincent; Stamatoullas, Aspasia; Mareschal, Sylvain; Viailly, Pierre-Julien; Sarafan-Vasseur, Nasrin; Bohers, Elodie; Dubois, Sydney; Picquenot, Jean Michel; Ruminy, Philippe; Maingonnat, Catherine; Bertrand, Philippe; Cornic, Marie; Tallon-Simon, Valérie; Becker, Stéphanie; Veresezan, Liana; Frebourg, Thierry; Vera, Pierre; Bastard, Christian; Tilly, Hervé; Jardin, Fabrice

2016-09-01

Classical Hodgkin lymphoma is one of the most common lymphomas and shares clinical and genetic features with primary mediastinal B-cell lymphoma. In this retrospective study, we analyzed the recurrent hotspot mutation of the exportin 1 (XPO1, p.E571K) gene, previously identified in primary mediastinal B-cell lymphoma, in biopsies and plasma circulating cell-free DNA from patients with classical Hodgkin lymphoma using a highly sensitive digital PCR technique. A total of 94 patients were included in the present study. This widely expressed XPO1 E571K mutation is present in one quarter of classical Hodgkin lymphoma patients (24.2%). Mutated and wild-type classical Hodgkin lymphomas were similar regarding the main clinical features. Patients with a detectable XPO1 mutation at the end of treatment displayed a tendency toward shorter progression-free survival, as compared to patients with undetectable mutation in plasma cell-free DNA (2-year progression-free survival: 57.1%, 95% confidence interval: 30.1-100% versus 2-year progression-free survival: 90.5%, 95% confidence interval: 78.8-100%, respectively, P=0.0601). To conclude, the detection of the XPO1 E571K mutation in biopsy and plasma cell-free DNA by digital PCR may be used as a novel biomarker in classical Hodgkin lymphoma for both diagnosis and minimal residual disease, and pinpoints a crucial role of XPO1 in classical Hodgkin lymphoma pathogenesis. The detection of somatic mutation in the plasma cell-free DNA of patients represents a major technological advance in the context of liquid biopsies and noninvasive management of classical Hodgkin lymphoma. Copyright© Ferrata Storti Foundation.

Plasma epidermal growth factor receptor mutation testing with a chip-based digital PCR system in patients with advanced non-small cell lung cancer.

PubMed

Kasahara, Norimitsu; Kenmotsu, Hirotsugu; Serizawa, Masakuni; Umehara, Rina; Ono, Akira; Hisamatsu, Yasushi; Wakuda, Kazushige; Omori, Shota; Nakashima, Kazuhisa; Taira, Tetsuhiko; Naito, Tateaki; Murakami, Haruyasu; Koh, Yasuhiro; Mori, Keita; Endo, Masahiro; Nakajima, Takashi; Yamada, Masanobu; Kusuhara, Masatoshi; Takahashi, Toshiaki

2017-04-01

Epidermal growth factor receptor (EGFR) mutation testing is a companion diagnostic to determine eligibility for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). Recently, plasma-based EGFR testing by digital polymerase chain reaction (dPCR), which enables accurate quantification of target DNA, has shown promise as a minimally invasive diagnostic. Here, we aimed to evaluate the accuracy of a plasma-based EGFR mutation test developed using chip-based dPCR-based detection of 3 EGFR mutations (exon 19 deletions, L858R in exon 21, and T790M in exon 20). Forty-nine patients with NSCLC harboring EGFR-activating mutations were enrolled, and circulating free DNAs (cfDNAs) were extracted from the plasma of 21 and 28 patients before treatment and after progression following EGFR-TKI treatment, respectively. Using reference genomic DNA containing each mutation, the detection limit of each assay was determined to be 0.1%. The sensitivity and specificity of detecting exon 19 deletions and L858R mutations, calculated by comparing the mutation status in the corresponding tumors, were 70.6% and 93.3%, and 66.7% and 100%, respectively, showing similar results compared with previous studies. T790M was detected in 43% of 28 cfDNAs after progression with EGFR-TKI treatment, but in no cfDNAs before the start of the treatment. This chip-based dPCR assay can facilitate detection of EGFR mutations in cfDNA as a minimally invasive method in clinical settings. Copyright © 2017 Elsevier B.V. All rights reserved.

Discrepancy of performance among working memory-related tasks in autism spectrum disorders was caused by task characteristics, apart from working memory, which could interfere with task execution.

PubMed

Nakahachi, Takayuki; Iwase, Masao; Takahashi, Hidetoshi; Honaga, Eiko; Sekiyama, Ryuji; Ukai, Satoshi; Ishii, Ryouhei; Ishigami, Wataru; Kajimoto, Osami; Yamashita, Ko; Hashimoto, Ryota; Tanii, Hisashi; Shimizu, Akira; Takeda, Masatoshi

2006-06-01

Working memory performance has been inconsistently reported in autism spectrum disorders (ASD). Several studies in ASD have found normal performance in digit span and poor performance in digit symbol task although these are closely related with working memory. It is assumed that poor performance in digit symbol could be explained by confirmatory behavior, which is induced due to the vague memory representation of number-symbol association. Therefore it was hypothesized that the performance of working memory task, in which vagueness did not cause confirmatory behavior, would be normal in ASD. For this purpose, the Advanced Trail Making Test (ATMT) was used. The performance of digit span, digit symbol and ATMT was compared between ASD and normal control. The digit span, digit symbol and ATMT was given to 16 ASD subjects and 28 IQ-, age- and sex-matched control subjects. The scores of these tasks were compared. A significantly lower score for ASD was found only in digit symbol compared with control subjects. There were no significant difference in digit span and working memory estimated by ATMT. Discrepancy of scores among working memory-related tasks was demonstrated in ASD. Poor digit symbol performance, normal digit span and normal working memory in ATMT implied that ASD subjects would be intact in working memory itself, and that superficial working memory dysfunction might be observed due to confirmatory behavior in digit symbol. Therefore, to evaluate working memory in ASD, tasks that could stimulate psychopathology specific to ASD should be avoided.

Propulsion controls

NASA Technical Reports Server (NTRS)

Harkney, R. D.

1980-01-01

Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems. The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept.

Cell-Free Plasma DNA-Guided Treatment With Osimertinib in Patients With Advanced EGFR-Mutated NSCLC.

PubMed

Buder, Anna; Hochmair, Maximilian J; Schwab, Sophia; Bundalo, Tatjana; Schenk, Peter; Errhalt, Peter; Mikes, Romana E; Absenger, Gudrun; Patocka, Kurt; Baumgartner, Bernhard; Setinek, Ulrike; Burghuber, Otto C; Prosch, Helmut; Pirker, Robert; Filipits, Martin

2018-03-02

Osimertinib is standard treatment for patients with advanced EGFR T790M-mutated non-small-cell lung cancer who have been pre-treated with EGFR-tyrosine kinase inhibitors (TKIs). We studied whether cell-free plasma DNA for T790M detection can be used to select patients for osimertinib treatment in the clinical routine. From April 2015 to November 2016, we included 119 patients with advanced EGFR-mutated non-small-cell lung cancer who had progressed under treatment with an EGFR-TKI. The T790M mutation status was assessed in cell-free plasma DNA by droplet digital polymerase chain reaction in all patients and by tissue analyses in selected patients. T790M mutations were detected in 85 (93%) patients by analyses of cell-free plasma DNA and in 6 (7%) plasma-negative patients by tumor re-biopsy. Eighty-nine of 91 T790M-positive patients received osimertinib. Median progression-free survival (PFS) was 10.1 months (95% confidence interval [CI]: 8.1-12.1). Median survival was not reached and the 1-year survival was 64%. The response rate was 70% in T790M-positive patients (n = 91) in the intention-to-treat population. PFS trended to be shorter in patients with high T790M copy number (≥10 copies/mL) compared to those with low T790M copy number (<10 copies/mL) (hazard ratio for PFS = 1.72, 95% CI: 0.92-3.2, p = 0.09). A comparable trend was observed for overall survival (hazard ratio for overall survival = 2.16, 95% CI: 0.89-5.25, p = 0.09). No difference in response rate was observed based on T790M copy numbers. Plasma genotyping using digital polymerase chain reaction is clinically useful for the selection of patients who had progressed during first-line EGFR-TKI therapy for treatment with osimertinib. Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Preliminary Design of a Digital Holography PFC Erosion Diagnostic for MPEX

NASA Astrophysics Data System (ADS)

Thomas, C. E. (Tommy), Jr.; Biewer, T. M.; Shaw, G. C.; Baylor, L. R.; Combs, S. K.; Meitner, S. J.; Rapp, J.; Hillis, D. L.; Granstedt, E. M.; Majeski, R.; Kaita, R.

2015-11-01

Preliminary design of a Digital Holography (DH) in-situ Plasma Facing Component (PFC) erosion diagnostic to be used on the proto-MPEX/MPEX experiment is presented. Design trade-offs are discussed including the selection of CO2 laser frequencies and whether/where to use reflective or refractive optical components. The costs and benefits of using a high-speed (expensive) infrared (IR) camera or a lower speed (inexpensive) IR camera, and whether to use simultaneous or sequential acquisition of DH exposures for the dual wavelength system are also described. Expected layout, resolution, and noise figures will be discussed, along with resolution and noise data from previous work at ORNL and PPPL. Partial Support from USDOE Contract DE-AC02-09CH11466 and USDOE Grant DE-FG02-07ER84724 for previous Digital Holography work done at ORNL and PPPL is gratefully acknowledged.

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

The UAH Spinning Terrella Experiment: A Laboratory Analog for the Earth's Magnetosphere

NASA Technical Reports Server (NTRS)

Sheldon, R. B.; Gallagher, D. L.; Craven, P. D.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

The UAH Spinning Terrella Experiment has been modified to include the effect of a second magnet. This is a simple laboratory demonstration of the well-known double-dipole approximation to the Earth's magnetosphere. In addition, the magnet has been biassed $\\sim$-400V which generates a DC glow discharge and traps it in a ring current around the magnet. This ring current is easily imaged with a digital camera and illustrates several significant topological properties of a dipole field. In particular, when the two dipoles are aligned, and therefore repel, they emulate a northward IMF Bz magnetosphere. Such a geometry traps plasma in the high latitude cusps as can be clearly seen in the movies. Likewise, when the two magnets are anti-aligned, they emulate a southward IMF Bz magnetosphere with direct feeding of plasma through the x-line. We present evidence for trapping and heating of the plasma, comparing the dipole-trapped ring current to the cusp-trapped population. We also present a peculiar asymmetric ring current produced in by the plasma at low plasma densities. We discuss the similarities and dissimilarities of the laboratory analog to the collisionless Earth plasma, and implications for the interpretation of IMAGE data.

Digital Controller For Acoustic Levitation

NASA Technical Reports Server (NTRS)

Tarver, D. Kent

1989-01-01

Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

Experience with synchronous and asynchronous digital control systems. [for flight

NASA Technical Reports Server (NTRS)

Regenie, Victoria A.; Chacon, Claude V.; Lock, Wilton P.

1986-01-01

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

Description and test results of a digital supersonic propulsion system integrated control

NASA Technical Reports Server (NTRS)

Batterton, P. G.; Arpasi, D. J.; Baumbick, R. J.

1976-01-01

A digitally implemented integrated inlet/engine control system was developed and tested on a mixed compression, Mach 2.5, supersonic inlet and augmented turbofan engine. The control matched engine airflow to available inlet airflow so that in steady state, the shock would be at the desired location, and the overboard bypass doors would be closed. During engine induced transients, such as augmentor lights and cutoffs, the inlet operating point was momentarily changed to a more supercritical point to minimize unstarts. The digital control also provided automatic inlet restart.

The Polar Plasma Wave Instrument

NASA Technical Reports Server (NTRS)

Gurnett, D. A.; Persoon, A. M.; Randall, R. F.; Odem, D. L.; Remington, S. L.; Averkamp, T. F.; Debower, M. M.; Hospodarsky, G. B.; Huff, R. L.; Kirchner, D. L.

1995-01-01

The Plasma Wave Instrument on the Polar spacecraft is designed to provide measurements of plasma waves in the Earth's polar regions over the frequency range from 0.1 Hz to 800 kHz. Three orthogonal electric dipole antennas are used to detect electric fields, two in the spin plane and one aligned along the spacecraft spin axis. A magnetic loop antenna and a triaxial magnetic search coil antenna are used to detect magnetic fields. Signals from these antennas are processed by five receiver systems: a wideband receiver, a high-frequency waveform receiver, a low-frequency waveform receiver, two multichannel analyzers; and a pair of sweep frequency receivers. Compared to previous plasma wave instruments, the Polar plasma wave instrument has several new capabilities. These include (1) an expanded frequency range to improve coverage of both low- and high-frequency wave phenomena, (2) the ability to simultaneously capture signals from six orthogonal electric and magnetic field sensors, and (3) a digital wideband receiver with up to 8-bit resolution and sample rates as high as 249k samples s(exp -1).

Helicon waves in uniform plasmas. IV. Bessel beams, Gendrin beams, and helicons

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

Urrutia, J. M.; Stenzel, R. L.

Electromagnetic waves in the low frequency whistler mode regime are investigated experimentally and by digital data superposition. The radiation from a novel circular antenna array is shown to produce highly collimated helicon beams in a uniform unbounded plasma. The differences to Bessel beams in free space are remarked upon. Low divergence beams arise from the parallel group velocity of whistlers with phase velocity either along the guide field or at the Gendrin angle. Waves with angular momentum are produced by phasing the array in the circular direction. The differences in the field topologies for positive and negative modes numbers aremore » shown. It is also shown that in uniform plasmas, the radial amplitude profile of the waves depends on the antenna field topology. Thus, there are no helicon “eigenmodes” with radial Bessel function profiles in uniform plasmas. It is pointed out that phase measurements in helicon devices indicate radial wave propagation which is inconsistent with helicon eigenmode theory based on paraxial wave propagation. Trivelpiece-Gould modes also exist in uniform unbounded plasmas.« less

Neurobehavioral effects of arsenic exposure among secondary school children in the Kandal Province, Cambodia

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

Vibol, Sao; Faculty of Agricultural Technology and Management, Royal University of Agriculture, Phnom Penh; Hashim, Jamal Hisham, E-mail: jamalhas@hotmail.com

The research was carried out at 3 study sites with varying groundwater arsenic (As) levels in the Kandal Province of Cambodia. Kampong Kong Commune was chosen as a highly contaminated site (300–500 μg/L), Svay Romiet Commune was chosen as a moderately contaminated site (50–300 μg/L) and Anlong Romiet Commune was chosen as a control site. Neurobehavioral tests on the 3 exposure groups were conducted using a modified WHO neurobehavioral core test battery. Seven neurobehavioral tests including digit symbol, digit span, Santa Ana manual dexterity, Benton visual retention, pursuit aiming, trail making and simple reaction time were applied. Children's hair samplesmore » were also collected to investigate the influence of hair As levels on the neurobehavioral test scores. The results from the inductively coupled plasma-mass spectrometry (ICP-MS) analyses of hair samples showed that hair As levels at the 3 study sites were significantly different (p<0.001), whereby hair samples from the highly contaminated site (n=157) had a median hair As level of 0.93 μg/g, while the moderately contaminated site (n=151) had a median hair As level of 0.22 μg/g, and the control site (n=214) had a median hair As level of 0.08 μg/g. There were significant differences among the 3 study sites for all the neurobehavioral tests scores, except for digit span (backward) test. Multiple linear regression clearly shows a positive significant influence of hair As levels on all the neurobehavioral test scores, except for digit span (backward) test, after controlling for hair lead (Pb), manganese (Mn) and cadmium (Cd). Children with high hair As levels experienced 1.57–4.67 times greater risk of having lower neurobehavioral test scores compared to those with low hair As levels, after adjusting for hair Pb, Mn and Cd levels and BMI status. In conclusion, arsenic-exposed school children from the Kandal Province of Cambodia with a median hair As level of 0.93 µg/g among those from the highly contaminated study site, showed clear evidence of neurobehavioral effects. - Highlights: • We measured the level of arsenic concentration in school secondary school children's hair. • As contamination in groundwater is the major source effect on the neurobehavioral performance of school children. • School children in highly and moderately contaminated sites are at risk of As exposure.« less

Development of a digital guidance and control law for steep approach automatic landings using modern control techniques

NASA Technical Reports Server (NTRS)

Halyo, N.

1979-01-01

The development of a digital automatic control law for a small jet transport to perform a steep final approach in automatic landings is reported along with the development of a steady-state Kalman filter used to provide smooth estimates to the control law. The control law performs the functions of localizer and glides capture, localizer and glideslope track, decrab, and place. The control law uses the microwave landing system position data, and aircraft body-mounted accelerators, attitude and attitude rate information. The results obtained from a digital simulation of the aircraft dynamics, wind conditions, and sensor noises using the control law and filter developed are described.

A satellite digital controller or 'play that PID tune again, Sam'. [Position, Integral, Derivative feedback control algorithm for design strategy

NASA Technical Reports Server (NTRS)

Seltzer, S. M.

1976-01-01

The problem discussed is to design a digital controller for a typical satellite. The controlled plant is considered to be a rigid body acting in a plane. The controller is assumed to be a digital computer which, when combined with the proposed control algorithm, can be represented as a sampled-data system. The objective is to present a design strategy and technique for selecting numerical values for the control gains (assuming position, integral, and derivative feedback) and the sample rate. The technique is based on the parameter plane method and requires that the system be amenable to z-transform analysis.

Effects of Aerobic Exercise on Mild Cognitive Impairment

PubMed Central

Baker, Laura D.; Frank, Laura L.; Foster-Schubert, Karen; Green, Pattie S.; Wilkinson, Charles W.; McTiernan, Anne; Plymate, Stephen R.; Fishel, Mark A.; Stennis Watson, G.; Cholerton, Brenna A.; Duncan, Glen E.; Mehta, Pankaj D.; Craft, Suzanne

2011-01-01

Objectives To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Design Six-month, randomized, controlled, clinical trial. Setting Veterans Affairs Puget Sound Health Care System clinical research unit. Participants Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Main Outcome Measures Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42. Results Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I and had a favorable effect only on Trails B performance. Conclusions This study provides support, using rigorous controlled methodology, for a potent nonpharma-cologic intervention that improves executive control processes for older women at high risk of cognitive decline. Moreover, our results suggest that a sex bias in cognitive response may relate to sex-based differences in glucometabolic and hypothalamic-pituitary-adrenal axis responses to aerobic exercise. PMID:20065132

76 FR 52715 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-23

... NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on September 7, 2011, Room T-2B1, 11545 Rockville...

76 FR 32240 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

... NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on June 7, 2011, Room T-2B1, 11545 Rockville Pike...

Analysis and design of digital output interface devices for gas turbine electronic controls

NASA Technical Reports Server (NTRS)

Newirth, D. M.; Koenig, E. W.

1976-01-01

A trade study was performed on twenty-one digital output interface schemes for gas turbine electronic controls to select the most promising scheme based on criteria of reliability, performance, cost, and sampling requirements. The most promising scheme, a digital effector with optical feedback of the fuel metering valve position, was designed.

77 FR 60480 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-03

... NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Digital Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on October 30, 2012, Room T-2B1, 11545 Rockville...

Cyber and physical equipment digital control system in Industry 4.0 item designing company

NASA Astrophysics Data System (ADS)

Gurjanov, A. V.; Zakoldaev, D. A.; Shukalov, A. V.; Zharinov, I. O.

2018-05-01

The problem of organization of digital control of the item designing company equipped with cyber and physical systems is being studied. A scheme of cyber and physical systems and personnel interaction in the Industry 4.0 smart factory company is presented. A scheme of assembly units transportation in the Industry 4.0 smart factory company is provided. A scheme of digital control system in the Industry 4.0 smart factory company is given.

One way Doppler Extractor. Volume 2: Digital VCO technique

NASA Technical Reports Server (NTRS)

Nossen, E. J.; Starner, E. R.

1974-01-01

A feasibility analysis and trade-offs for a one-way Doppler extractor using digital VCO techniques is presented. The method of Doppler measurement involves the use of a digital phase lock loop; once this loop is locked to the incoming signal, the precise frequency and hence the Doppler component can be determined directly from the contents of the digital control register. The only serious error source is due to internally generated noise. Techniques are presented for minimizing this error source and achieving an accuracy of 0.01 Hz in a one second averaging period. A number of digitally controlled oscillators were analyzed from a performance and complexity point of view. The most promising technique uses an arithmetic synthesizer as a digital waveform generator.

Flight test validation of a design procedure for digital autopilots

NASA Technical Reports Server (NTRS)

Bryant, W. H.

1983-01-01

Commercially available general aviation autopilots are currently in transition from an analogue circuit system to a computer implemented digital flight control system. Well known advantages of the digital autopilot include enhanced modes, self-test capacity, fault detection, and greater computational capacity. A digital autopilot's computational capacity can be used to full advantage by increasing the sophistication of the digital autopilot's chief function, stability and control. NASA's Langley Research Center has been pursuing the development of direct digital design tools for aircraft stabilization systems for several years. This effort has most recently been directed towards the development and realization of multi-mode digital autopilots for GA aircraft, conducted under a SPIFR-related program called the General Aviation Terminal Operations Research (GATOR) Program. This presentation focuses on the implementation and testing of a candidate multi-mode autopilot designed using these newly developed tools.

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.

Digital frequency control of satellite frequency standards. [Defense Navigation Satellites

NASA Technical Reports Server (NTRS)

Nichols, S. A.

1973-01-01

In the Frequency and Time Standard Development Program of the TIMATION System, a new miniaturized rubidium vapor frequency standard has been tested and analyzed for possible use on the TIMATION 3A launch, as part of the Defense Navigation Satellite Development Program. The design and construction of a digital frequency control was required to remotely control this rubidium vapor frequency standard as well as the quartz oscillator in current use. This control must be capable of accepting commands from a satellite telemetry system, verify that the correct commands have been sent and control the frequency to the requirements of the system. Several modifications must be performed to the rubidium vapor frequency standard to allow it to be compatible with the digital frequency control. These include the addition of a varactor to voltage tune the coarse range of the flywheel oscillator, and a modification to supply the C field current externally. The digital frequency control for the rubidium vapor frequency standard has been successfully tested in prototype form.

Inverse heat transfer problem in digital temperature control in plate fin and tube heat exchangers

NASA Astrophysics Data System (ADS)

Taler, Dawid; Sury, Adam

2011-12-01

The aim of the paper is a steady-state inverse heat transfer problem for plate-fin and tube heat exchangers. The objective of the process control is to adjust the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a preset value. Two control techniques were developed. The first is based on the presented mathematical model of the heat exchanger while the second is a digital proportional-integral-derivative (PID) control. The first procedure is very stable. The digital PID controller becomes unstable if the water volumetric flow rate changes significantly. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments showed that the PID controller works also well but becomes frequently unstable.

A combined event-related potential and neuropsychological investigation of developmental dyscalculia.

PubMed

Soltész, Fruzsina; Szucs, Dénes; Dékány, Judit; Márkus, Attila; Csépe, Valéria

2007-05-01

Adolescents with developmental dyscalculia (DD) but no other impairments were examined with neuropsychological tests and with event-related brain potentials (ERPs). A matched control group and an adult control group were tested as well. Behavioural and ERP markers of the magnitude representation were examined in a task where subjects decided whether visually presented Hindu-Arabic digits were smaller or larger than 5. There was a normal behavioural numerical distance effect (better performance for digits closer to the reference number than for digits further away from it) in DD. This suggests that semantic magnitude relations depend on a phenomenologically (nearly) normal magnitude representation in DD, at least in the range of single-digit numbers. However, minor discrepancies between DD subjects and controls suggest that the perception of the magnitude of single digits may be slightly impaired in DD. Early ERP distance effects were similar in DD and in control subjects. In contrast, between 400 and 440 ms there was a focused right-parietal ERP distance effect in controls, but not in DD. This suggests that early, more automatic processing of digits was similar in both groups, and between-group processing differences arose later, during more complex controlled processing. This view is supported by signs of decelerated executive functioning in developmental dyscalculia. Further, DD subjects did not differ from controls in general mental rotation and in body parts knowledge, but were markedly impaired in mental finger rotation, finger knowledge, and tactile performance.

Frequency control circuit for all-digital phase-lock loops

NASA Technical Reports Server (NTRS)

Anderson, T. O.

1973-01-01

Phase-lock loop references all its operations to fixed high-frequency service clock operating at highest speed which digital circuits permit. Wide-range control circuit provides linear control of frequency of reference signal. It requires only two counters in combination with control circuit consisting only of flip-flop and gate.

Microelectromechanical accelerometer with resonance-cancelling control circuit including an idle state

DOEpatents

Chu, Dahlon D.; Thelen, Jr., Donald C.; Campbell, David V.

2001-01-01

A digital feedback control circuit is disclosed for use in an accelerometer (e.g. a microelectromechanical accelerometer). The digital feedback control circuit, which periodically re-centers a proof mass in response to a sensed acceleration, is based on a sigma-delta (.SIGMA..DELTA.) configuration that includes a notch filter (e.g. a digital switched-capacitor filter) for rejecting signals due to mechanical resonances of the proof mass and further includes a comparator (e.g. a three-level comparator). The comparator generates one of three possible feedback states, with two of the feedback states acting to re-center the proof mass when that is needed, and with a third feedback state being an "idle" state which does not act to move the proof mass when no re-centering is needed. Additionally, the digital feedback control system includes an auto-zero trim capability for calibration of the accelerometer for accurate sensing of acceleration. The digital feedback control circuit can be fabricated using complementary metal-oxide semiconductor (CMOS) technology, bi-CMOS technology or bipolar technology and used in single- and dual-proof-mass accelerometers.

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.

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

A gallium-arsenide digital phase shifter for clock and control signal distribution in high-speed digital systems

NASA Technical Reports Server (NTRS)

Fouts, Douglas J.

1992-01-01

The design, implementation, testing, and applications of a gallium-arsenide digital phase shifter and fan-out buffer are described. The integrated circuit provides a method for adjusting the phase of high-speed clock and control signals in digital systems, without the need for pruning cables, multiplexing between cables of different lengths, delay lines, or similar techniques. The phase of signals distributed with the described chip can be dynamically adjusted in eight different steps of approximately 60 ps per step. The IC also serves as a fan-out buffer and provides 12 in-phase outputs. The chip is useful for distributing high-speed clock and control signals in synchronous digital systems, especially if components are distributed over a large physical area or if there is a large number of components.

Digital combined instrument transformer for automated electric power supply control systems of mining companies

NASA Astrophysics Data System (ADS)

Topolsky, D. V.; Gonenko, T. V.; Khatsevskiy, V. F.

2017-10-01

The present paper discusses ways to solve the problem of enhancing operating efficiency of automated electric power supply control systems of mining companies. According to the authors, one of the ways to solve this problem is intellectualization of the electric power supply control system equipment. To enhance efficiency of electric power supply control and electricity metering, it is proposed to use specially designed digital combined instrument current and voltage transformers. This equipment conforms to IEC 61850 international standard and is adapted for integration into the digital substation structure. Tests were performed to check conformity of an experimental prototype of the digital combined instrument current and voltage transformer with IEC 61850 standard. The test results have shown that the considered equipment meets the requirements of the standard.

BEAMing LAMP: single-molecule capture and on-bead isothermal amplification for digital detection of hepatitis C virus in plasma.

PubMed

Chen, Jiyun; Xu, Xiaomin; Huang, Zhimei; Luo, Yuan; Tang, Lijuan; Jiang, Jian-Hui

2018-01-02

A novel dNAD platform (BEAMing LAMP) by combining emulsion micro-reactors, single-molecule magnetic capture and on-bead loop-mediated isothermal amplification has been developed for DNA detection, which enables absolute and high-precision quantification of a target with a detection limit of 300 copies.

High-Power Helicon Double Gun Thruster

NASA Astrophysics Data System (ADS)

Murakami, Nao

While chemical propulsion is necessary to launch a spacecraft from a planetary surface into space, electric propulsion has the potential to provide significant cost savings for the orbital transfer of payloads between planets. Due to extended wave particle interactions, a plasma thruster that can operate in the 100 kW to several MW power regime can only be attained by increasing the size of the thruster, or by using an array of plasma thrusters. The High-Power Helicon (HPH) Double Gun thruster experiment examines whether firing two helicon thrusters in parallel produces an exhaust velocity higher than the exhaust velocity of a single thruster. The scaling law that relates the downstream plasma velocity with the number of helicon antennae is derived, and compared with the experimental result. In conjunction with data analysis, two digital filtering algorithms are developed to filter out the noise from helicon antennae. The scaling law states that the downstream plasma velocity is proportional to square root of the number of helicon antennae, which is in agreement with the experimental result.

A PICKSC Science Gateway for enabling the common plasma physicist to run kinetic software

NASA Astrophysics Data System (ADS)

Hu, Q.; Winjum, B. J.; Zonca, A.; Youn, C.; Tsung, F. S.; Mori, W. B.

2017-10-01

Computer simulations offer tremendous opportunities for studying plasmas, ranging from simulations for students that illuminate fundamental educational concepts to research-level simulations that advance scientific knowledge. Nevertheless, there is a significant hurdle to using simulation tools. Users must navigate codes and software libraries, determine how to wrangle output into meaningful plots, and oftentimes confront a significant cyberinfrastructure with powerful computational resources. Science gateways offer a Web-based environment to run simulations without needing to learn or manage the underlying software and computing cyberinfrastructure. We discuss our progress on creating a Science Gateway for the Particle-in-Cell and Kinetic Simulation Software Center that enables users to easily run and analyze kinetic simulations with our software. We envision that this technology could benefit a wide range of plasma physicists, both in the use of our simulation tools as well as in its adaptation for running other plasma simulation software. Supported by NSF under Grant ACI-1339893 and by the UCLA Institute for Digital Research and Education.

Reflection high energy electron diffraction study of nitrogen plasma interactions with a GaAs (100) surface

NASA Astrophysics Data System (ADS)

Hauenstein, R. J.; Collins, D. A.; Cai, X. P.; O'Steen, M. L.; McGill, T. C.

1995-05-01

Effect of a nitrogen electron-cyclotron-resonance (ECR) microwave plasma on near-surface composition, crystal structure, and morphology of the As-stabilized GaAs (100) surface is investigated with the use of digitally image-processed in situ reflection high energy electron diffraction. Nitridation is performed on molecular beam epitaxially (MBE) grown GaAs surfaces near 600 °C under typical conditions for ECR microwave plasma-assisted MBE growth of GaN films on GaAs. Brief plasma exposures (≊3-5 s) are shown to result in a specular, coherently strained, relatively stable, GaN film approximately one monolayer in thickness, which can be commensurately overgrown with GaAs while longer exposures (up to 1 min) result in incommensurate zincblende epitaxial GaN island structures. Specular and nonspecular film formations are explained in terms of N-for-As surface and subsurface anion exchange reactions, respectively. Commensurate growth of ultrathin buried GaN layers in GaAs is achieved.

Flight evaluation of modifications to a digital electronic engine control system in an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Myers, L. P.; Zeller, J. R.

1983-01-01

The third phase of a flight evaluation of a digital electronic engine control system in an F-15 has recently been completed. It was found that digital electronic engine control software logic changes and augmentor hardware improvements resulted in significant improvements in engine operation. For intermediate to maximum power throttle transients, an increase in altitude capability of up to 8000 ft was found, and for idle to maximum transients, an increase of up to 4000 ft was found. A nozzle instability noted in earlier flight testing was investigated on a test engine at NASA Lewis Research Center, a digital electronic engine control software logic change was developed and evaluated, and no instability occurred in the Phase 3 flight evaluation. The backup control airstart modification was evaluated, and gave an improvement of airstart capability by reducing the minimum airspeed for successful airstarts by 50 to 75 knots.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

2005-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor)

2004-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Digital controller for a Baum folding machine. [providing automatic counting and machine shutoff

NASA Technical Reports Server (NTRS)

Bryant, W. H. (Inventor)

1974-01-01

A digital controller for controlling the operation of a folding machine enables automatic folding of a desired number of sheets responsive to entry of that number into a selector. The controller includes three decade counter stages for corresponding rows of units, tens and hundreds push buttons. Each stage including a decimal-to-BCD encoder, a buffer register, and a digital or binary counter. The BCD representation of the selected count for each digit is loaded into the respective decade down counters. Pulses generated by a sensor and associated circuitry are used to decrease the count in the decade counters. When the content of the decade counter reaches either 0 or 1, a solenoid control valve is actuated which interrupts operation of the machine. A repeat switch, when actuated, prevents clearing of the buffer registers so that multiple groups of the same number of sheets can be folded without reentering the number into the selector.

THOR Fields and Wave Processor - FWP

NASA Astrophysics Data System (ADS)

Soucek, Jan; Rothkaehl, Hanna; Ahlen, Lennart; Balikhin, Michael; Carr, Christopher; Dekkali, Moustapha; Khotyaintsev, Yuri; Lan, Radek; Magnes, Werner; Morawski, Marek; Nakamura, Rumi; Uhlir, Ludek; Yearby, Keith; Winkler, Marek; Zaslavsky, Arnaud

2017-04-01

If selected, Turbulence Heating ObserveR (THOR) will become the first spacecraft mission dedicated to the study of plasma turbulence. The Fields and Waves Processor (FWP) is an integrated electronics unit for all electromagnetic field measurements performed by THOR. FWP will interface with all THOR fields sensors: electric field antennas of the EFI instrument, the MAG fluxgate magnetometer, and search-coil magnetometer (SCM), and perform signal digitization and on-board data processing. FWP box will house multiple data acquisition sub-units and signal analyzers all sharing a common power supply and data processing unit and thus a single data and power interface to the spacecraft. Integrating all the electromagnetic field measurements in a single unit will improve the consistency of field measurement and accuracy of time synchronization. The scientific value of highly sensitive electric and magnetic field measurements in space has been demonstrated by Cluster (among other spacecraft) and THOR instrumentation will further improve on this heritage. Large dynamic range of the instruments will be complemented by a thorough electromagnetic cleanliness program, which will prevent perturbation of field measurements by interference from payload and platform subsystems. Taking advantage of the capabilities of modern electronics and the large telemetry bandwidth of THOR, FWP will provide multi-component electromagnetic field waveforms and spectral data products at a high time resolution. Fully synchronized sampling of many signals will allow to resolve wave phase information and estimate wavelength via interferometric correlations between EFI probes. FWP will also implement a plasma resonance sounder and a digital plasma quasi-thermal noise analyzer designed to provide high cadence measurements of plasma density and temperature complementary to data from particle instruments. FWP will rapidly transmit information about magnetic field vector and spacecraft potential to the particle instrument data processing unit (PPU) via a dedicated digital link. This information will help particle instruments to optimize energy and angular sweeps and calculate on-board moments. FWP will also coordinate the acquisition of high resolution waveform snapshots with very high time resolution electron data from the TEA instrument. This combined wave/particle measurement will provide the ultimate dataset for investigation of wave-particle interactions on electron scales. The FWP instrument shall be designed and built by an international consortium of scientific institutes from Czech Republic, Poland, France, UK, Sweden and Austria.

Sustained response to standard dose osimertinib in a patient with plasma T790M-positive leptomeningeal metastases from primary lung adenocarcinoma.

PubMed

Chan, Oscar Siu-Hong; Leung, Warren Kam-Wing; Yeung, Rebecca Mei-Wan

2017-12-01

A 44-year-old male, never smoker, suffers from stage IV adenocarcinoma of the right lung with epidermal growth factor receptor (EGFR) exon-21 L858R point mutation on initial presentation. After 23 months of treatment with gefitinib, intercalated with multiple courses of radiotherapy, leptomeningeal metastases (LMs) developed. Acquired T790M mutation was confirmed by the droplet digital polymerase chain reaction plasma EGFR test. After switching to osimertinib at the standard dose, his neurocognitive function improved clinically, coupled with sustained radiological improvement. As this clinical entity is underrepresented in clinical trials, the practicability of plasma EGFR testing and the optimal dose-response relationship of osimertinib in T790M-positive lung cancer complicated with LM deserves further exploration. © 2017 John Wiley & Sons Australia, Ltd.

Apollo experience report: Guidance and control systems - Digital autopilot design development

NASA Technical Reports Server (NTRS)

Peters, W. H.; Cox, K. J.

1973-01-01

The development of the Apollo digital autopilots (the primary attitude control systems that were used for all phases of the lunar landing mission) is summarized. This report includes design requirements, design constraints, and design philosophy. The development-process functions and the essential information flow paths are identified. Specific problem areas that existed during the development are included. A discussion is also presented on the benefits inherent in mechanizing attitude-controller logic and dynamic compensation in a digital computer.

Verification of the Chesapeake Bay Model.

DTIC Science & Technology

1981-12-01

points on the model. Each inflow control unit consists of a pressure regulator , a digital flow control valve, and a flowmeter (Fig- ure 8). A mechanical...spring-type pressure regulator ensures constant pressure to the digital flow control valve. Each digital valve contains eight solenoid valve actuators...FT) =0.798 EEOC 1DGS 2.78 EPOCH (DEGS) - 11. 84 3 DATA TAKEN: AC(0) = 0. 11 38 F T A (0)= 0. 1653 FT 28 MAR 1978 RANGE (FT) - 1.638 RANGE (FT

Old/New Effect of Digital Memory Retrieval in Chinese Dyscalculia.

PubMed

Wang, Enguo; Du, Chenguang; Ma, Yujun

This study reports the neurophysiological and behavioral correlates of digital memory retrieval features in Chinese individuals with and without dyscalculia. A total of 18 children with dyscalculia (ages 11.5-13.5) and 18 controls were tested, and their event-related potentials were digitally recorded simultaneously with behavior measurement. Behavioral data showed that the dyscalculia group had lower hit rates and higher false rates than the control group. The electroencephalography results showed that both groups had a significant old/new effect and that this effect was greater in the control group. In the 300 to 400 ms processing stages, both groups showed significant differences in digital memory retrieval in the frontal regions. In the 400 to 500 and 500 to 600 ms epochs, the old/new effect in the control group was significantly greater than it was in the dyscalculia group at the frontal, central, and parietal regions. In the 600 to 700 ms processing stages, both groups showed significant differences in digital memory retrieval in the frontal, central, parietal, and occipital regions. These results suggest that individuals with dyscalculia exhibit impaired digital memory retrieval. Extraction failure may be an important cause of calculation difficulties.

Machine vision for digital microfluidics

NASA Astrophysics Data System (ADS)

Shin, Yong-Jun; Lee, Jeong-Bong

2010-01-01

Machine vision is widely used in an industrial environment today. It can perform various tasks, such as inspecting and controlling production processes, that may require humanlike intelligence. The importance of imaging technology for biological research or medical diagnosis is greater than ever. For example, fluorescent reporter imaging enables scientists to study the dynamics of gene networks with high spatial and temporal resolution. Such high-throughput imaging is increasingly demanding the use of machine vision for real-time analysis and control. Digital microfluidics is a relatively new technology with expectations of becoming a true lab-on-a-chip platform. Utilizing digital microfluidics, only small amounts of biological samples are required and the experimental procedures can be automatically controlled. There is a strong need for the development of a digital microfluidics system integrated with machine vision for innovative biological research today. In this paper, we show how machine vision can be applied to digital microfluidics by demonstrating two applications: machine vision-based measurement of the kinetics of biomolecular interactions and machine vision-based droplet motion control. It is expected that digital microfluidics-based machine vision system will add intelligence and automation to high-throughput biological imaging in the future.

Description and theory of operation of the computer by-pass system for the NASA F-8 digital fly-by-wire control system

NASA Technical Reports Server (NTRS)

1978-01-01

A triplex digital flight control system was installed in a NASA F-8C airplane to provide fail operate, full authority control. The triplex digital computers and interface circuitry process the pilot commands and aircraft motion feedback parameters according to the selected control laws, and they output the surface commands as an analog signal to the servoelectronics for position control of the aircraft's power actuators. The system and theory of operation of the computer by pass and servoelectronics are described and an automated ground test for each axis is included.

Digital flight control systems

NASA Technical Reports Server (NTRS)

Caglayan, A. K.; Vanlandingham, H. F.

1977-01-01

The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

Digital servo control of random sound test excitation. [in reverberant acoustic chamber

NASA Technical Reports Server (NTRS)

Nakich, R. B. (Inventor)

1974-01-01

A digital servocontrol system for random noise excitation of a test object in a reverberant acoustic chamber employs a plurality of sensors spaced in the sound field to produce signals in separate channels which are decorrelated and averaged. The average signal is divided into a plurality of adjacent frequency bands cyclically sampled by a time division multiplex system, converted into digital form, and compared to a predetermined spectrum value stored in digital form. The results of the comparisons are used to control a time-shared up-down counter to develop gain control signals for the respective frequency bands in the spectrum of random sound energy picked up by the microphones.

Digital and analog communication systems

NASA Technical Reports Server (NTRS)

Shanmugam, K. S.

1979-01-01

The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

Formulation of a strategy for monitoring control integrity in critical digital control systems

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

1991-01-01

Advanced aircraft will require flight critical computer systems for stability augmentation as well as guidance and control that must perform reliably in adverse, as well as nominal, operating environments. Digital system upset is a functional error mode that can occur in electromagnetically harsh environments, involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. A strategy is presented for dynamic upset detection to be used in the evaluation of critical digital controllers during the design and/or validation phases of development. Critical controllers must be able to be used in adverse environments that result from disturbances caused by an electromagnetic source such as lightning, high intensity radiated field (HIRF), and nuclear electromagnetic pulses (NEMP). The upset detection strategy presented provides dynamic monitoring of a given control computer for degraded functional integrity that can result from redundancy management errors and control command calculation error that could occur in an electromagnetically harsh operating environment. The use is discussed of Kalman filtering, data fusion, and decision theory in monitoring a given digital controller for control calculation errors, redundancy management errors, and control effectiveness.

Development of a digital automatic control law for steep glideslope capture and flare

NASA Technical Reports Server (NTRS)

Halyo, N.

1977-01-01

A longitudinal digital guidance and control law for steep glideslopes using MLS (Microwave Landing System) data is developed for CTOL aircraft using modern estimation and control techniques. The control law covers the final approach phases of glideslope capture, glideslope tracking, and flare to touchdown for automatic landings under adverse weather conditions. The control law uses a constant gain Kalman filter to process MLS and body-mounted accelerometer data to form estimates of flight path errors and wind velocities including wind shear. The flight path error estimates and wind estimates are used for feedback in generating control surface commands. Results of a digital simulation of the aircraft dynamics and the guidance and control law are presented for various wind conditions.

Omniview motionless camera orientation system

NASA Technical Reports Server (NTRS)

Martin, H. Lee (Inventor); Kuban, Daniel P. (Inventor); Zimmermann, Steven D. (Inventor); Busko, Nicholas (Inventor)

2010-01-01

An apparatus and method is provided for converting digital images for use in an imaging system. The apparatus includes a data memory which stores digital data representing an image having a circular or spherical field of view such as an image captured by a fish-eye lens, a control input for receiving a signal for selecting a portion of the image, and a converter responsive to the control input for converting digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. Various methods include the steps of storing digital data representing an image having a circular or spherical field of view, selecting a portion of the image, and converting the stored digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. In various embodiments, the data converter and data conversion step may use an orthogonal set of transformation algorithms.

Creating an EPICS Based Test Stand Development System for a BPM Digitizer of the Linac Coherent Light Source

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

Not Available

2011-06-22

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test themore » digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. Finally, logging of meaningful data into files has been added.« less

Modeling and control of plasma rotation for NSTX 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.; Gerhardt, S. P.; Boyer, M. D.; Andre, R.; Kolemen, E.; Taira, K.

2016-03-01

A model-based feedback system is presented to control plasma rotation in a magnetically confined toroidal fusion device, to maintain plasma stability for long-pulse operation. This research uses experimental measurements from the National Spherical Torus Experiment (NSTX) and is aimed at controlling plasma rotation using two different types of actuation: momentum from injected neutral beams and neoclassical toroidal viscosity generated by three-dimensional applied magnetic fields. Based on the data-driven model obtained, a feedback controller is designed, and predictive simulations using the TRANSP plasma transport code show that the controller is able to attain desired plasma rotation profiles given practical constraints on the actuators and the available measurements of rotation.

Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection

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

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

2016-02-19

A model-based feedback system is presented to control plasma rotation in a magnetically confined toroidal fusion device, to maintain plasma stability for long-pulse operation. This research uses experimental measurements from the National Spherical Torus Experiment (NSTX) and is aimed at controlling plasma rotation using two different types of actuation: momentum from injected neutral beams and neoclassical toroidal viscosity generated by three-dimensional applied magnetic fields. Based on the data-driven model obtained, a feedback controller is designed, and predictive simulations using the TRANSP plasma transport code show that the controller is able to attain desired plasma rotation profiles given practical constraints onmore » the actuators and the available measurements of rotation.« less

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.

Digital temperature and velocity control of mach 0.3 atmospheric pressure durability testing burner rigs in long time, unattended cyclic testing

NASA Technical Reports Server (NTRS)

Deadmore, D. L.

1985-01-01

Hardware and software were developed to implement the hybrid digital control of two Jet A-1 fueled Mach 0.3 burners from startup to completion of a preset number of hot corrosion flame durability cycle tests of materials at 1652 F. This was accomplished by use of a basic language programmable microcomputer and data aquisition and control unit connected together by the IEEE-488 Bus. The absolute specimen temperature was controlled to + or - 3 F by use of digital adjustment of the fuel flow using a P-I-D (Proportional-Integral-Derivative) control algorithm. The specimen temperature was within + or - 2 F of the set point more than 90 percent of the time. Pressure control was achieved by digital adjustment of the combustion air flow using a proportional control algorithm. The burner pressure was controlled at 1.0 + or - 0.02 psig. Logic schemes were incorporated into the system to protect the test specimen from abnormal test conditions in the event of a hardware of software malfunction.

Digital robust active control law synthesis for large order systems using constrained optimization

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek

1987-01-01

This paper presents a direct digital control law synthesis procedure for a large order, sampled data, linear feedback system using constrained optimization techniques to meet multiple design requirements. A linear quadratic Gaussian type cost function is minimized while satisfying a set of constraints on the design loads and responses. General expressions for gradients of the cost function and constraints, with respect to the digital control law design variables are derived analytically and computed by solving a set of discrete Liapunov equations. The designer can choose the structure of the control law and the design variables, hence a stable classical control law as well as an estimator-based full or reduced order control law can be used as an initial starting point. Selected design responses can be treated as constraints instead of lumping them into the cost function. This feature can be used to modify a control law, to meet individual root mean square response limitations as well as minimum single value restrictions. Low order, robust digital control laws were synthesized for gust load alleviation of a flexible remotely piloted drone aircraft.

Design of multichord Hα detector arrays for the U-3M torsatron and identification of rotating plasma perturbations

NASA Astrophysics Data System (ADS)

Dreval, M. B.; Shapoval, A. M.; Ozherelyev, F. I.; Makhov, M. M.

2016-07-01

An Hα camera has been designed and installed in the U-3M torsatron for spatially and temporally resolved measurements. This device provides fast measurements of the emission brightness profile in the noisy environment of the radio frequency (RF) heated plasma. Unusual topology of diagnostics and the data acquisition system are applied. All the system components, including digitizers, are assembled in a single unit. It allows the suppression of a low-frequency electromagnetic interference by eliminating the ground loops. And the suppression of RF noises is achieved by eliminating the signal interface cables and digital interface cables in the design. The Wi-Fi interface is used to prevent a ground loop in the data transfer stage. The achieved sensitivity of our diagnostics is high enough for measuring the Hα emission from the low-density (ne ≈ (1-2)ṡ1010 cm-3) plasma with a temporal resolution of about 20 μs in the noisy environment. Different types of Hα emission fluctuations within the frequency range of 1-5 kHz and poloidal mode numbers m = 0 and m = 5 have been observed in U-3M. A simple technique of the line-of-sight data analysis, based on the U-3M magnetic surface asymmetry, is proposed and used for the spatial localization of the rotating mode and for the determination of mode numbers and its poloidal rotation direction using a single Hα array.

Fault detection and accommodation testing on an F100 engine in an F-15 airplane. [digital engine control system

NASA Technical Reports Server (NTRS)

Myers, L. P.; Baer-Riedhart, J. L.; Maxwell, M. D.

1985-01-01

The fault detection and accommodation (FDA) methods that can be used for digital engine control systems are presently subjected to a flight test program in the case of the F-15 fighter's F100 engine electronic controls, inducing selected faults and then evaluating the resulting digital engine control responses. In general, flight test results were found to compare well with both ground tests and predictions. It is noted that the inducement of dual-pressure failures was not feasible, since FDA logic was not designed to accommodate them.

Use of early tactile stimulation in rehabilitation of digital nerve injuries.

PubMed

Cheng, A S

2000-01-01

Digital nerves are the most frequently injured peripheral nerve. To improve the recovery of functional sensibility of digital nerve injuries, a prospective randomized controlled study was conducted to see the effect of using early tactile stimulation in rehabilitation of digital nerve injuries. Two specific tactile stimulators were made and prescribed for patients with digital nerve-injury. Twenty-four participants with 32 digital nerve injuries received the prescribed tactile stimulators (experimental group), and another 25 participants with 33 digital nerve injuries received only routine conventional therapy (control group). A significant difference (p < .05) was seen in the experimental group, although there were some variations between the different classes of associated injuries, with least benefit observed in the combined nerve, tendon, and bone injury class. Use of early tactile stimulation as described in this study can be considered an effective way to improve both quality and quantity of recovery of functional sensibility in digital nerve injuries without combined nerve, tendon, and bone injuries.

Operational viewpoint of the X-29A digital flight control system

NASA Technical Reports Server (NTRS)

Chacon, Vince; Mcbride, David

1988-01-01

In the past few years many flight control systems have been implemented as full-authority, full-time digital systems. The digital design has allowed flight control systems to make use of many enhanced elements that are generally considered too complex to implement in an analog system. Examples of these elements are redundant information exchanged between channels to allow for continued operation after multiple failures and multiple variable gain schedules to optimize control of the aircraft throughout its flight envelope and in all flight modes. The introduction of the digital system for flight control also created the problem of obtaining information from the system in an understandable and useful format. This paper presents how the X-29A was dealt with during its operations at NASA Ames-Dryden Flight Research Facility. A brief description of the X-29A control system, a discussion of the tools developed to aid in daily operations, and the troubleshooting of the aircraft are included.

ESR1 and PIK3CA mutational status in serum and plasma from metastatic breast cancer patients: A comparative study.

PubMed

Takeshita, Takashi; Yamamoto, Yutaka; Yamamoto-Ibusuki, Mutsuko; Tomiguchi, Mai; Sueta, Aiko; Iwase, Hirotaka

2018-04-07

Plasma and serum cell-free DNA (cfDNA) are useful sources of tumor DNA, but comparative investigations of the tumor mutational status between them are rare. we performed droplet digital PCR assay for representative hotspot mutations in metastatic breast cancer (MBC) (ESR1 and PIK3CA) in serum and plasma cfDNA concurrently extracted from the blood of 33 estrogen receptor-positive MBC patients. ESR1 mutations in plasma cfDNA were found in 7 of the 33 patients; ESR1 mutations in serum cfDNA were detected in only one out of 7 patients with ESR1 mutations in plasma cfDNA. PIK3CA exon 9 and exon 20 mutations in plasma cfDNA were found in 3 and 7 out of the 33 patients, respectively; PIK3CA exon 9 mutations in serum cfDNA were detected in 2 out of 3 patients with PIK3CA exon 9 mutations in plasma cfDNA; PIK3CA exon 20 mutations in serum cfDNA were detected in 2 out of 7 patients with PIK3CA exon 20 mutations in plasma cfDNA. Here we show the higher frequency of ESR1 and PIK3CA mutations in the plasma than in the serum in 33 MBC patients; therefore, serum samples should not be considered the preferred source of cfDNA.

A Closed-Loop Proportional-Integral (PI) Control Software for Fully Mechanically Controlled Automated Electron Microscopic Tomography

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

REN, GANG; LIU, JINXIN; LI, HONGCHANG

A closed-loop proportional-integral (PI) control software is provided for fully mechanically controlled automated electron microscopic tomography. The software is developed based on Gatan DigitalMicrograph, and is compatible with Zeiss LIBRA 120 transmission electron microscope. However, it can be expanded to other TEM instrument with modification. The software consists of a graphical user interface, a digital PI controller, an image analyzing unit, and other drive units (i.e.: image acquire unit and goniometer drive unit). During a tomography data collection process, the image analyzing unit analyzes both the accumulated shift and defocus value of the latest acquired image, and provides the resultsmore » to the digital PI controller. The digital PI control compares the results with the preset values and determines the optimum adjustments of the goniometer. The goniometer drive unit adjusts the spatial position of the specimen according to the instructions given by the digital PI controller for the next tilt angle and image acquisition. The goniometer drive unit achieves high precision positioning by using a backlash elimination method. The major benefits of the software are: 1) the goniometer drive unit keeps pre-aligned/optimized beam conditions unchanged and achieves position tracking solely through mechanical control; 2) the image analyzing unit relies on only historical data and therefore does not require additional images/exposures; 3) the PI controller enables the system to dynamically track the imaging target with extremely low system error.« less

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.

Cognitive impairments of alcoholic cirrhotic patients: correlation with endogenous benzodiazepine receptor ligands and increased affinity of platelet receptors.

PubMed Central

Kapczinski, F; Curran, H V; Przemioslo, R; Williams, R; Fluck, E; Fernandes, C; File, S E

1996-01-01

OBJECTIVES--To determine whether differences in cognitive function between alcoholic and non-alcoholic cirrhotic patients relate to differences in endogenous ligands for the benzodiazepine receptor and/or benzodiazepine binding. METHODS--Seventeen grade-I hepatic encephalopathic patients (nine alcoholic, eight non-alcoholic) were compared with 10 matched controls on plasma concentrations of endogenous ligands for the neuronal benzodiazepine receptor, benzodiazepine binding in platelets, and performance on tests of cognitive function. RESULTS--Both groups of patients were impaired on verbal recall and on reaction time tasks compared with controls; alcoholic patients were also impaired on Reitan's trails test and digit cancellation. Four of the 17 patients had detectable concentrations of endogenous benzodiazepine ligands and they were more impaired than other patients on trails and cancellation tests. The groups did not differ in the density of benzodiazepine platelet receptors, but receptor affinity was higher in alcoholic patients than in controls; furthermore, receptor affinity correlated with the time to complete the cancellation task and with reaction time. CONCLUSION--Alcoholic cirrhotic patients may have enhanced concentrations of ligands for neuronal and peripheral benzodiazepine receptors and these may contribute to cognitive impairments in these patients. PMID:8648337

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.

The trend of digital control system design for nuclear power plants in Korea

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

Park, S. H.; Jung, H. Y.; Yang, C. Y.

2006-07-01

Currently there are 20 nuclear power plants (NPPs) in operation, and 6 more units are under construction in Korea. The control systems of those NPPs have also been developed together with the technology advancement. Control systems started with On-Off control using the relay logic, had been evolved into Solid-State logic using TTL ICs, and applied with the micro-processors since the Yonggwang NPP Units 3 and 4 which started its construction in 1989. Multiplexers are also installed at the local plant areas to collect field input and to send output signals while communicating with the controllers located in the system cabinetsmore » near the main control room in order to reduce the field wiring cables. The design of the digital control system technology for the NPPs in Korea has been optimized to maximize the operability as well as the safety through the design, construction, start-up and operation experiences. Both Shin-Kori Units 1 and 2 and Shin-Wolsong Units 1 and 2 NPP projects under construction are being progressed at the same time. Digital Plant Control Systems of these projects have adopted multi-loop controllers, redundant loop configuration, and soft control system for the radwaste system. Programmable Logic Controller (PLC) and Distributed Control System (DCS) are applied with soft control system in Shin-Kori Units 3 and 4. This paper describes the evolvement of control system at the NPPs in Korea and the experience and design improvement through the observation of the latest failure of the digital control system. In addition, design concept and its trend of the digital control system being applied to the NPP in Korea are introduced. (authors)« less

Digital memory encoding in Chinese dyscalculia: An event-related potential study.

PubMed

Wang, Enguo; Qin, Shutao; Chang, MengYan; Zhu, Xiangru

2014-10-22

This study reports the neurophysiological and behavioral correlates of digital memory encoding features in Chinese individuals with and without dyscalculia. Eighteen children with dyscalculia (ages 11.5-13.5) and 18 matched controls were tested, and their event-related potentials (ERPs) were digitally recorded simultaneously with behavioral measures. The results showed that both groups had a significant Dm effect, and this effect was greater in the control group. In the 300-400-ms, 400-500-ms, and 600-700-ms processing stages, both groups showed significant differences of digital memory encoding in the frontal, central, and parietal regions. In the 500-600-ms period, the Dm effect in the control group was significantly greater than that in the dyscalculia group only in the parietal region. These results suggest that individuals with dyscalculia exhibit impaired digital memory encoding and deficits in psychological resource allocation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Description and Flight Test Results of the NASA F-8 Digital Fly-by-Wire Control System

NASA Technical Reports Server (NTRS)

1975-01-01

A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

Stand-alone digital data storage control system including user control interface

NASA Technical Reports Server (NTRS)

Wright, Kenneth D. (Inventor); Gray, David L. (Inventor)

1994-01-01

A storage control system includes an apparatus and method for user control of a storage interface to operate a storage medium to store data obtained by a real-time data acquisition system. Digital data received in serial format from the data acquisition system is first converted to a parallel format and then provided to the storage interface. The operation of the storage interface is controlled in accordance with instructions based on user control input from a user. Also, a user status output is displayed in accordance with storage data obtained from the storage interface. By allowing the user to control and monitor the operation of the storage interface, a stand-alone, user-controllable data storage system is provided for storing the digital data obtained by a real-time data acquisition system.

Digital Versus Conventional Impressions in Fixed Prosthodontics: A Review.

PubMed

Ahlholm, Pekka; Sipilä, Kirsi; Vallittu, Pekka; Jakonen, Minna; Kotiranta, Ulla

2018-01-01

To conduct a systematic review to evaluate the evidence of possible benefits and accuracy of digital impression techniques vs. conventional impression techniques. Reports of digital impression techniques versus conventional impression techniques were systematically searched for in the following databases: Cochrane Central Register of Controlled Trials, PubMed, and Web of Science. A combination of controlled vocabulary, free-text words, and well-defined inclusion and exclusion criteria guided the search. Digital impression accuracy is at the same level as conventional impression methods in fabrication of crowns and short fixed dental prostheses (FDPs). For fabrication of implant-supported crowns and FDPs, digital impression accuracy is clinically acceptable. In full-arch impressions, conventional impression methods resulted in better accuracy compared to digital impressions. Digital impression techniques are a clinically acceptable alternative to conventional impression methods in fabrication of crowns and short FDPs. For fabrication of implant-supported crowns and FDPs, digital impression systems also result in clinically acceptable fit. Digital impression techniques are faster and can shorten the operation time. Based on this study, the conventional impression technique is still recommended for full-arch impressions. © 2016 by the American College of Prosthodontists.

Zolpidem 10 mg given at daytime is not antagonized by 300 mg caffeine in man.

PubMed

Mattila, M J; Nurminen, M L; Vainio, P; Vanakoski, J

1998-07-01

Caffeine counteracts various effects of traditional benzodiazepines (BZDs). As zolpidem, a short-acting hypnotic, is an atypical GABAA-BZD agonist, we investigated when caffeine would counteract the effects of zolpidem as well. In daytime study I, zolpidem 10 mg (capsule) and caffeine 150 or 300 mg (in decaffeinated coffee) were given, alone and in combinations, to parallel groups (n = 15-17) of healthy students in double-blind and placebo-controlled manner. Objective and subjective tests were done before and 45 min and 90 min after intake. Ranked delta values (changes from baseline) were analysed by one-way contrast ANOVA and Scheffe's tests. In daytime study II, four healthy subjects took zolpidem 10 mg alone, and together with blinded caffeine 250 mg or (at -45 min) erythromycin 750 mg. Objective and subjective effects were measured and plasma zolpidem concentrations assayed at baseline and 45 min and 90 min after zolpidem intake. In study I, practice effects after placebo (ad + 30%) were seen for letter cancellation and digit symbol substitution but not for flicker fusion tests. Zolpidem alone significantly impaired (P < 0.05 vs delta placebo) letter cancellation and digit symbol substitution at 45 min and 90 min, lowered the flicker fusion threshold at 45 min, and caused subjective drowsiness, mental slowness, clumsiness and feeling of poor performance. Caffeine alone showed a non-significant trend to improve objective performance. The combined effects of zolpidem and either dose of caffeine matched those measured after zolpidem alone. Zolpidem + caffeine 300 mg was not stronger than zolpidem + caffeine 150 mg in impairing immediate memory and causing subjective sedation. In study II, zolpidem caused objective and subjective sedation; neither caffeine nor erythromycin modulated the effects of zolpidem or plasma zolpidem concentrations. The sedative effects of 10 mg of zolpidem are not antagonized by 150-300 mg of caffeine in pharmacodynamic or pharmacokinetic terms.

Polytropic scaling of a flow Z-pinch

NASA Astrophysics Data System (ADS)

Hughes, M. C.; Shumlak, U.; Nelson, B. A.; Golingo, R. P.; Claveau, E. L.; Doty, S. A.; Forbes, E. G.; Kim, B.; Ross, M. P.; Weed, J. R.

2015-11-01

The ZaP Flow Z-Pinch project investigates the use of velocity shear to mitigate MHD instabilities. The ZaP-HD experiment produces 50 cm long pinches of varying radii. The power to the experiment is split between the plasma formation and acceleration process and the pinch assembly and compression process. Once the pinch is formed, low magnetic fluctuations indicate a quiescent, long-lived pinch. The split power supply allows more control of the pinch current than previous machine iterations, with a designed range from 50 to 150 kA. Radial force balance leads to the Bennett relation which indicates that as the pinch compresses due to increasing currents, the plasma pressure and/or linear density must change. Through ion spectroscopy and digital holographic interferometry coupled with magnetic measurements of the pinch current, the components of the Bennett relation can be fully measured. A scaling relation is then assumed to follow a polytrope as the pinch pressure, initially approximately 250 kPa, increases from an initially formed state to much higher values, approaching 100 MPa. A preliminary analysis of pinch scaling is shown corroborating with other diagnostics on the machine along with extrapolations to required currents for an HEDLP machine. This work is supported by grants from the U.S. Department of Energy and the U.S. National Nuclear Security Administration.

Step-by-Step Design of an FPGA-Based Digital Compensator for DC/DC Converters Oriented to an Introductory Course

ERIC Educational Resources Information Center

Zumel, P.; Fernandez, C.; Sanz, M.; Lazaro, A.; Barrado, A.

2011-01-01

In this paper, a short introductory course to introduce field-programmable gate array (FPGA)-based digital control of dc/dc switching power converters is presented. Digital control based on specific hardware has been at the leading edge of low-medium power dc/dc switching converters in recent years. Besides industry's interest in this topic, from…

Human Factors Guidance for Control Room and Digital Human-System Interface Design and Modification, Guidelines for Planning, Specification, Design, Licensing, Implementation, Training, Operation and Maintenance

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

R. Fink, D. Hill, J. O'Hara

2004-11-30

Nuclear plant operators face a significant challenge designing and modifying control rooms. This report provides guidance on planning, designing, implementing and operating modernized control rooms and digital human-system interfaces.

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.

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.

Field-programmable analogue arrays for the sensorless control of DC motors

NASA Astrophysics Data System (ADS)

Rivera, J.; Dueñas, I.; Ortega, S.; Del Valle, J. L.

2018-02-01

This work presents the analogue implementation of a sensorless controller for direct current motors based on the super-twisting (ST) sliding mode technique, by means of field programmable analogue arrays (FPAA). The novelty of this work is twofold, first is the use of the ST algorithm in a sensorless scheme for DC motors, and the implementation method of this type of sliding mode controllers in FPAAs. The ST algorithm reduces the chattering problem produced with the deliberate use of the sign function in classical sliding mode approaches. On the other hand, the advantages of the implementation method over a digital one are that the controller is not digitally approximated, the controller gains are not fine tuned and the implementation does not require the use of analogue-to-digital and digital-to-analogue converter circuits. In addition to this, the FPAA is a reconfigurable, lower cost and power consumption technology. Simulation and experimentation results were registered, where a more accurate transient response and lower power consumption were obtained by the proposed implementation method when compared to a digital implementation. Also, a more accurate performance by the DC motor is obtained with proposed sensorless ST technique when compared with a classical sliding mode approach.

Integrated mixed signal control IC for 500-kHz switching frequency buck regulator

NASA Astrophysics Data System (ADS)

Chen, Keng; Zhang, Hong

2015-12-01

The main purpose for this work is to study the challenges of designing a digital buck regulator using pipelined analog to digital converter (ADC). Although pipelined ADC can achieve high sampling speed, it will introduce additional phase lag to the buck circuit. Along with the latency brought by processing time of additional digital circuits, as well as the time delay associated with the switching frequency, the closed loop will be unstable; moreover, raw ADC outputs have low signal-to-noise ratio, which usually need back-end calibration. In order to compensate these phase lag and make control loop unconditional stable, as well as boost up signal-to-noise ratio of the ADC block with cost-efficient design, a finite impulse response filter followed by digital proportional-integral-derivative blocks were designed. All these digital function blocks were optimised with processing speed. In the system simulation, it can be found that this controller achieved output regulation within 10% of nominal 5 V output voltage under 1 A/µs load transient condition; moreover, with the soft-start method, there is no turn-on overshooting. The die size of this controller is controlled within 3 mm2 by using 180 nm CMOS technology.

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.

Analog circuit for controlling acoustic transducer arrays

DOEpatents

Drumheller, Douglas S.

1991-01-01

A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.

Iterative learning-based decentralized adaptive tracker for large-scale systems: a digital redesign approach.

PubMed

Tsai, Jason Sheng-Hong; Du, Yan-Yi; Huang, Pei-Hsiang; Guo, Shu-Mei; Shieh, Leang-San; Chen, Yuhua

2011-07-01

In this paper, a digital redesign methodology of the iterative learning-based decentralized adaptive tracker is proposed to improve the dynamic performance of sampled-data linear large-scale control systems consisting of N interconnected multi-input multi-output subsystems, so that the system output will follow any trajectory which may not be presented by the analytic reference model initially. To overcome the interference of each sub-system and simplify the controller design, the proposed model reference decentralized adaptive control scheme constructs a decoupled well-designed reference model first. Then, according to the well-designed model, this paper develops a digital decentralized adaptive tracker based on the optimal analog control and prediction-based digital redesign technique for the sampled-data large-scale coupling system. In order to enhance the tracking performance of the digital tracker at specified sampling instants, we apply the iterative learning control (ILC) to train the control input via continual learning. As a result, the proposed iterative learning-based decentralized adaptive tracker not only has robust closed-loop decoupled property but also possesses good tracking performance at both transient and steady state. Besides, evolutionary programming is applied to search for a good learning gain to speed up the learning process of ILC. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Development of the HIDEC inlet integration mode. [Highly Integrated Digital Electronic Control

NASA Technical Reports Server (NTRS)

Chisholm, J. D.; Nobbs, S. G.; Stewart, J. F.

1990-01-01

The Highly Integrated Digital Electronic Control (HIDEC) development program conducted at NASA-Ames/Dryden will use an F-15 test aircraft for flight demonstration. An account is presently given of the HIDEC Inlet Integration mode's design concept, control law, and test aircraft implementation, with a view to its performance benefits. The enhancement of performance is a function of the use of Digital Electronic Engine Control corrected engine airflow computations to improve the scheduling of inlet ramp positions in real time; excess thrust can thereby be increased by 13 percent at Mach 2.3 and 40,000 ft. Aircraft supportability is also improved through the obviation of inlet controllers.

F-8C digital CCV flight control laws

NASA Technical Reports Server (NTRS)

Hartmann, G. L.; Hauge, J. A.; Hendrick, R. C.

1976-01-01

A set of digital flight control laws were designed for the NASA F-8C digital fly-by-wire aircraft. The control laws emphasize Control Configured Vehicle (CCV) benefits. Specific pitch axis objectives were improved handling qualities, angle-of-attack limiting, gust alleviation, drag reduction in steady and maneuvering flight, and a capability to fly with reduced static stability. The lateral-directional design objectives were improved Dutch roll damping and turn coordination over a wide range in angle-of-attack. An overall program objective was to explore the use of modern control design methodilogy to achieve these specific CCV benefits. Tests for verifying system integrity, an experimental design for handling qualities evaluation, and recommended flight test investigations were specified.

Trends in software reliability for digital flight control

NASA Technical Reports Server (NTRS)

Hecht, H.; Hecht, M.

1983-01-01

Software error data of major recent Digital Flight Control Systems Development Programs. The report summarizes the data, compare these data with similar data from previous surveys and identifies trends and disciplines to improve software reliability.

21 CFR 1311.35 - Number of CSOS digital certificates needed.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Number of CSOS digital certificates needed. 1311... FOR ELECTRONIC ORDERS AND PRESCRIPTIONS Obtaining and Using Digital Certificates for Electronic Orders § 1311.35 Number of CSOS digital certificates needed. A purchaser of Schedule I and II controlled...

21 CFR 1311.145 - Digitally signing the prescription with the individual practitioner's private key.

Code of Federal Regulations, 2012 CFR

2012-04-01

... individual practitioner's private key. 1311.145 Section 1311.145 Food and Drugs DRUG ENFORCEMENT... Prescriptions § 1311.145 Digitally signing the prescription with the individual practitioner's private key. (a... digitally sign a controlled substance prescription using the private key associated with his digital...

21 CFR 1311.145 - Digitally signing the prescription with the individual practitioner's private key.

Code of Federal Regulations, 2011 CFR

2011-04-01

... individual practitioner's private key. 1311.145 Section 1311.145 Food and Drugs DRUG ENFORCEMENT... Prescriptions § 1311.145 Digitally signing the prescription with the individual practitioner's private key. (a... digitally sign a controlled substance prescription using the private key associated with his digital...

21 CFR 1311.145 - Digitally signing the prescription with the individual practitioner's private key.

Code of Federal Regulations, 2014 CFR

2014-04-01

... individual practitioner's private key. 1311.145 Section 1311.145 Food and Drugs DRUG ENFORCEMENT... Prescriptions § 1311.145 Digitally signing the prescription with the individual practitioner's private key. (a... digitally sign a controlled substance prescription using the private key associated with his digital...

21 CFR 1311.145 - Digitally signing the prescription with the individual practitioner's private key.

Code of Federal Regulations, 2013 CFR

2013-04-01

... individual practitioner's private key. 1311.145 Section 1311.145 Food and Drugs DRUG ENFORCEMENT... Prescriptions § 1311.145 Digitally signing the prescription with the individual practitioner's private key. (a... digitally sign a controlled substance prescription using the private key associated with his digital...

Three on a Match: Gary A. Olson on Rigor, Reliability, and Quality Control in Digital Scholarship

ERIC Educational Resources Information Center

Jensen, Kyle

2009-01-01

This interview examines the relationship between digital scholarship and the politics of higher education. In doing so, it advances a series of recommendations that aim to help digital scholars and digital scholarship achieve an increased level of stature in the academic community.

Shaping of nested potentials for electron cooling of highly-charged ions in a cooler Penning trap

NASA Astrophysics Data System (ADS)

Paul, Stefan; Kootte, Brian; Lascar, Daniel; Gwinner, Gerald; Dilling, Jens; Titan Collaboration

2016-09-01

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is dedicated to mass spectrometry and decay spectroscopy of short-lived radioactive nuclides in a series of ion traps including a precision Penning trap. In order to boost the achievable precision of mass measurements TITAN deploys an Electron Beam Ion Trap (EBIT) providing Highly-Charged Ions (HCI). However, the charge breeding process in the EBIT leads to an increase in the ion bunch's energy spread which is detrimental to the overall precision gain. To reduce this effect a new cylindrical Cooler PEnning Trap (CPET) is being commissioned to sympathetically cool the HCI via a simultaneously trapped electron plasma. Simultaneous trapping of ions and electrons requires a high level of control over the nested potential landscape and sophisticated switching schemes for the voltages on CPET's multiple ring electrodes. For this purpose, we are currently setting up a new experimental control system for multi-channel voltage switching. The control system employs a Raspberry Pi communicating with a digital-to-analog board via a serial peripheral interface. We report on the implementation of the voltage control system and its performance with respect to electron and ion manipulation in CPET. University of British Columbia, Vancouver, BC, Canada.

The multiple-function multi-input/multi-output digital controller system for the AFW wind-tunnel model

NASA Technical Reports Server (NTRS)

Hoadley, Sherwood T.; Mcgraw, Sandra M.

1992-01-01

A real time multiple-function digital controller system was developed for the Active Flexible Wing (AFW) Program. The digital controller system (DCS) allowed simultaneous execution of two control laws: flutter suppression and either roll trim or a rolling maneuver load control. The DCS operated within, but independently of, a slower host operating system environment, at regulated speeds up to 200 Hz. It also coordinated the acquisition, storage, and transfer of data for near real time controller performance evaluation and both open- and closed-loop plant estimation. It synchronized the operation of four different processing units, allowing flexibility in the number, form, functionality, and order of control laws, and variability in the selection of the sensors and actuators employed. Most importantly, the DCS allowed for the successful demonstration of active flutter suppression to conditions approximately 26 percent (in dynamic pressure) above the open-loop boundary in cases when the model was fixed in roll and up to 23 percent when it was free to roll. Aggressive roll maneuvers with load control were achieved above the flutter boundary. The purpose here is to present the development, validation, and wind tunnel testing of this multiple-function digital controller system.

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.

Comparison of Communication Architectures and Network Topologies for Distributed Propulsion Controls (Preprint)

DTIC Science & Technology

2013-05-01

logic to perform control function computations and are connected to the full authority digital engine control ( FADEC ) via a high-speed data...Digital Engine Control ( FADEC ) via a high speed data communication bus. The short term distributed engine control configu- rations will be core...concen- trator; and high temperature electronics, high speed communication bus between the data concentrator and the control law processor master FADEC

Design and evaluation of a sensor fail-operational control system for a digitally controlled turbofan engine

NASA Technical Reports Server (NTRS)

Hrach, F. J.; Arpasi, D. J.; Bruton, W. M.

1975-01-01

A self-learning, sensor fail-operational, control system for the TF30-P-3 afterburning turbofan engine was designed and evaluated. The sensor fail-operational control system includes a digital computer program designed to operate in conjunction with the standard TF30-P-3 bill-of-materials control. Four engine measurements and two compressor face measurements are tested. If any engine measurements are found to have failed, they are replaced by values synthesized from computer-stored information. The control system was evaluated by using a realtime, nonlinear, hybrid computer engine simulation at sea level static condition, at a typical cruise condition, and at several extreme flight conditions. Results indicate that the addition of such a system can improve the reliability of an engine digital control system.

Computer Instructional Aids for Undergraduate Control Education. 1978 Edition.

ERIC Educational Resources Information Center

Volz, Richard A.; And Others

This work represents the development of computer tools for undergraduate students. Emphasis is on automatic control theory using hybrid and digital computation. The routine calculations of control system analysis are presented as students would use them on the University of Michigan's central digital computer and the time-shared graphic terminals…

Fast, optically controlled Kerr phase shifter for digital signal processing.

PubMed

Li, R B; Deng, L; Hagley, E W; Payne, M G; Bienfang, J C; Levine, Z H

2013-05-01

We demonstrate an optically controlled Kerr phase shifter using a room-temperature 85Rb vapor operating in a Raman gain scheme. Phase shifts from zero to π relative to an unshifted reference wave are observed, and gated operations are demonstrated. We further demonstrate the versatile digital manipulation of encoded signal light with an encoded phase-control light field using an unbalanced Mach-Zehnder interferometer. Generalizations of this scheme should be capable of full manipulation of a digitized signal field at high speed, opening the door to future applications.

Laboratory Instrumentation Design Research for Scalable Next Generation Epitaxy: Non-Equilibrium Wide Application Epitaxial Patterning by Intelligent Control (NEW-EPIC). Volume 1. 3D Composition/Doping Control via Micromiror Patterned Deep UV Photodesorption: Revolutionary in situ Characterization/Control

DTIC Science & Technology

2009-02-19

magnesium dopant concentration. A digital micromirror device is introduced to pattern incident UV radiation during InGaN growth, demonstrating that the...magnesium dopant concentration. A digital micromirror device is introduced to pattern incident UV radiation during InGaN growth, demonstrating that the...successful compositional patterning of InGaN using in situ digital micromirror device (DMD) patterning of ultraviolet (UV

Evaluation of a high response electrohydraulic digital control valve

NASA Technical Reports Server (NTRS)

Anderson, R. L.

1973-01-01

The application is described of a digital control valve on an electrohydraulic servo actuator. The digital control problem is discussed in general as well as the design and evaluation of a breadboard actuator. The evaluation revealed a number of problems associated with matching the valve to a hydraulic load. The problems were related to lost motion resulting from bulk modulus and leakage. These problems were effectively minimized in the breadboard actuator by maintaining a 1000 psi back pressure on the valve circuit and thereby improving the effective bulk modulus.

Technologies of the 21st Century for ground-based Ionospheric Sounding, in Support of Space Missions

NASA Astrophysics Data System (ADS)

Wright, J. W.; Zabotin, N. A.; Bullett, T.; Livingston, R. C.

Modern digital systems technology is transforming the familiar ionosonde from its former role (to "make ionograms"), into a versatile instrument for precision measurement. The excellent Signal/Noise capability of plasma total reflection is combined with a complete characterization of ionospheric echoes in radio-frequency, time and localization, using multiple and identical digital receivers. High standards of RF emission minimize interference to other systems while yielding unprecedented resolution and stability for echo phase and amplitude. In turn, this information is rapidly digested to produce 3-dimensional local plasma density distributions, vector velocities, and irregularity spectral parameters; in most cases these are complete with error estimations. Results appear in real time, as at the prototype Web Application, http://www.ngdc.noaa.gov/stp/IONO/Dynasonde/. At this site, older hardware manages to approximate the performance standards of the new Dynasonde instrument now in development at Scion Associates, while serving to design and validate innovations in diagnostic capabilities and data access. The "all-sky" and continuous observations that characterize modern ionosonde methods offer strong ground-based support to spacecraft including C/NOFS, DMSP, COSMIC, etc., as well as to assimilative modeling programs such as GAIM.

Design of Distributed Engine Control Systems for Stability Under Communication Packet Dropouts

DTIC Science & Technology

2009-08-01

remarks. II. Distributed Engine Control Systems A. FADEC based on Distributed Engine Control Architecture (DEC) In Distributed Engine...Control, the functions of Full Authority Digital Engine Control ( FADEC ) are distributed at the component level. Each sensor/actuator is to be replaced...diagnostics and health management functionality. Dual channel digital serial communication network is used to connect these smart modules with FADEC . Fig

Integrated dynamic analysis simulation of space stations with controllable solar arrays (supplemental data and analyses)

NASA Technical Reports Server (NTRS)

Heinrichs, J. A.; Fee, J. J.

1972-01-01

Space station and solar array data and the analyses which were performed in support of the integrated dynamic analysis study. The analysis methods and the formulated digital simulation were developed. Control systems for space station altitude control and solar array orientation control include generic type control systems. These systems have been digitally coded and included in the simulation.

Factors influencing optical 3D scanning of vinyl polysiloxane impression materials.

PubMed

DeLong, R; Pintado, M R; Ko, C C; Hodges, J S; Douglas, W H

2001-06-01

Future growth in dental practice lies in digital imaging enhancing many chairside procedures and functions. This revolution requires the fast, accurate, and 3D digitizing of clinical records. One such clinical record is the chairside impression. This study investigated how surface angle and surface roughness affect the digitizing of vinyl polysiloxane impression materials. Seventeen vinyl polysiloxane impression materials were digitized with a white light optical digitizing system. Each sample was digitized at 3 different angles: 0 degrees, 22.5 degrees, and 45 degrees, and 2 digitizer camera f-stops. The digitized images were rendered on a computer monitor using custom software developed under NIH/NIDCR grant DE12225. All the 3D images were rotated to the 0 degrees position, cropped using Corel Photo-Paint 8 (Corel Corp, Ottawa, Ontario, Canada), then saved in the TIFF file format. The impression material area that was successfully digitized was calculated as a percentage of the total sample area, using Optimas 5.22 image processing software (Media Cybernetics, LP, Silver Spring, MD). The dependent variable was a Performance Value calculated for each material by averaging the percentage of area that digitized over the 3 angles. New samples with smooth and rough surfaces were made using the 7 impression materials with the largest Performance Values. These samples were tested as before, but with the additional angle of 60 degrees. Silky-Rock die stone (Whip Mix Corp, Louisville, KY) was used as a control. The Performance Values for the 17 impression materials ranged from 0% to 100%. The Performance Values for the 7 best materials were equivalent to the control at f/11 out to a surface angle of 45 degrees; however, only Examix impression material (GC America Inc, Alsip, IL) was equivalent to the control at f/11/\\16. At the 60 degrees surface angle with f/11/\\16, the Performance Values were 0% for all the impression materials, whereas that for the control was 90%. The difference in the Performance Values for the smooth and rough surface textures was 7%, which was not significant. The digitizing performance of vinyl polysiloxane impression materials is highly material and surface angle-dependent and is significantly lower than the die stone control when angles to 60 degrees are included. It is affected to a lesser extent by surface texture. Copyright 2001 by The American College of Prosthodontists.

Digital Flight Control System Redundancy Study

DTIC Science & Technology

1974-07-01

has its own separate power supr, y . d. Digital Processor The digital processor consists of the followdnq components: (1) Program Counter - This...1-3 Yaw Axis Control 108 1-4 Autothrottle (Airspeed Hold Mode) 109 1-5 Approach Power Compensation 110 1-6 Glideslope Flare 111 I-7 Glideslope Track...considsred to the extent that they imposed constraints on the candidate con- figurations. Cost, size, weight, power , maintainability, survivability and

Flight testing the digital electronic engine control in the F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.

1984-01-01

The digital electronic engine control (DEEC) is a full-authority digital engine control developed for the F100-PW-100 turbofan engine which was flight tested on an F-15 aircraft. The DEEC hardware and software throughout the F-15 flight envelope was evaluated. Real-time data reduction and data display systems were implemented. New test techniques and stronger coordination between the propulsion test engineer and pilot were developed which produced efficient use of test time, reduced pilot work load, and greatly improved quality data. The engine pressure ratio (EPR) control mode is demonstrated. It is found that the nonaugmented throttle transients and engine performance are satisfactory.

Image Acquisition and Quality in Digital Radiography.

PubMed

Alexander, Shannon

2016-09-01

Medical imaging has undergone dramatic changes and technological breakthroughs since the introduction of digital radiography. This article presents information on the development of digital radiography and types of digital radiography systems. Aspects of image quality and radiation exposure control are highlighted as well. In addition, the article includes related workplace changes and medicolegal considerations in the digital radiography environment. ©2016 American Society of Radiologic Technologists.

A Fully Integrated Sensor SoC with Digital Calibration Hardware and Wireless Transceiver at 2.4 GHz

PubMed Central

Kim, Dong-Sun; Jang, Sung-Joon; Hwang, Tae-Ho

2013-01-01

A single-chip sensor system-on-a-chip (SoC) that implements radio for 2.4 GHz, complete digital baseband physical layer (PHY), 10-bit sigma-delta analog-to-digital converter and dedicated sensor calibration hardware for industrial sensing systems has been proposed and integrated in a 0.18-μm CMOS technology. The transceiver's building block includes a low-noise amplifier, mixer, channel filter, receiver signal-strength indicator, frequency synthesizer, voltage-controlled oscillator, and power amplifier. In addition, the digital building block consists of offset quadrature phase-shift keying (OQPSK) modulation, demodulation, carrier frequency offset compensation, auto-gain control, digital MAC function, sensor calibration hardware and embedded 8-bit microcontroller. The digital MAC function supports cyclic redundancy check (CRC), inter-symbol timing check, MAC frame control, and automatic retransmission. The embedded sensor signal processing block consists of calibration coefficient calculator, sensing data calibration mapper and sigma-delta analog-to-digital converter with digital decimation filter. The sensitivity of the overall receiver and the error vector magnitude (EVM) of the overall transmitter are −99 dBm and 18.14%, respectively. The proposed calibration scheme has a reduction of errors by about 45.4% compared with the improved progressive polynomial calibration (PPC) method and the maximum current consumption of the SoC is 16 mA. PMID:23698271

Comparison between the effects of platelet-rich plasma and bone marrow concentrate on defect consolidation in the rabbit tibia

PubMed Central

Batista, Marco Antonio; Leivas, Tomaz Puga; Rodrigues, Consuelo Junqueira; Arenas, Géssica Cantadori Funes; Belitardo, Donizeti Rodrigues; Guarniero, Roberto

2011-01-01

OBJECTIVE: To perform a comparative analysis of the effects of platelet-rich plasma and centrifuged bone marrow aspirate on the induction of bone healing in rabbits. METHOD: Twenty adult, male New Zealand rabbits were randomly separated into two equal groups, and surgery was performed to create a bone defect (a cortical orifice 3.3 mm in diameter) in the proximal metaphysis of each rabbit's right tibia. In the first group, platelet-rich plasma was implanted in combination with β-tricalcium phosphate (platelet-rich plasma group), and in the second group, centrifuged bone marrow in combination with β-tricalcium phosphate (centrifuged bone marrow group) was implanted. After a period of four weeks, the animals were euthanized, and the tibias were evaluated using digital radiography, computed tomography, and histomorphometry. RESULTS: Seven samples from each group were evaluated. The radiographic evaluation confirmed the absence of fractures in the postoperative limb and identified whether bone consolidation had occurred. The tomographic evaluation revealed a greater amount of consolidation and the formation of a greater cortical bone thickness in the platelet-rich plasma group. The histomorphometry revealed a greater bone density in the platelet-rich plasma group compared with the centrifuged bone marrow group. CONCLUSION: After four weeks, the platelet-rich plasma promoted a greater amount of bone consolidation than the bone marrow aspirate concentrate. PMID:22012052

BacNet and Analog/Digital Interfaces of the Building Controls Virtual Testbed

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

Nouidui, Thierry Stephane; Wetter, Michael; Li, Zhengwei

2011-11-01

This paper gives an overview of recent developments in the Building Controls Virtual Test Bed (BCVTB), a framework for co-simulation and hardware-in-the-loop. First, a general overview of the BCVTB is presented. Second, we describe the BACnet interface, a link which has been implemented to couple BACnet devices to the BCVTB. We present a case study where the interface was used to couple a whole building simulation program to a building control system to assess in real-time the performance of a real building. Third, we present the ADInterfaceMCC, an analog/digital interface that allows a USB-based analog/digital converter to be linked tomore » the BCVTB. In a case study, we show how the link was used to couple the analog/digital converter to a building simulation model for local loop control.« less

Interference elimination in digital controllers of automation systems of oil and gas complex

NASA Astrophysics Data System (ADS)

Solomentsev, K. Yu; Fugarov, D. D.; Purchina, O. A.; Poluyan, A. Y.; Nesterchuk, V. V.; Petrenkova, S. B.

2018-05-01

The given article considers the problems arising in the process of digital governors development for the systems of automatic control. In the case of interference, and also in case of high frequency of digitization, digital differentiation gives a big error. The problem is that the derivative is calculated as the difference of two close variables. The method of differentiation is offered to reduce this error, when there is a case of averaging the difference quotient of the series of meanings. The structure chart for the implementation of this differentiation method is offered in the case of governors construction.

Feed-forward digital phase and amplitude correction system

DOEpatents

Yu, D.U.L.; Conway, P.H.

1994-11-15

Phase and amplitude modifications in repeatable RF pulses at the output of a high power pulsed microwave amplifier are made utilizing a digital feed-forward correction system. A controlled amount of the output power is coupled to a correction system for processing of phase and amplitude information. The correction system comprises circuitry to compare the detected phase and amplitude with the desired phase and amplitude, respectively, and a digitally programmable phase shifter and attenuator and digital logic circuitry to control the phase shifter and attenuator. The phase and amplitude of subsequent are modified by output signals from the correction system. 11 figs.

Feed-forward digital phase and amplitude correction system

DOEpatents

Yu, David U. L.; Conway, Patrick H.

1994-01-01

Phase and amplitude modifications in repeatable RF pulses at the output of a high power pulsed microwave amplifier are made utilizing a digital feed-forward correction system. A controlled amount of the output power is coupled to a correction system for processing of phase and amplitude information. The correction system comprises circuitry to compare the detected phase and amplitude with the desired phase and amplitude, respectively, and a digitally programmable phase shifter and attenuator and digital logic circuitry to control the phase shifter and attenuator. The Phase and amplitude of subsequent are modified by output signals from the correction system.

A plasma rotation control scheme for NSTX and NSTX-U

NASA Astrophysics Data System (ADS)

Goumiri, Imene

2016-10-01

Plasma rotation has been proven to play a key role in stabilizing large scale instabilities and improving plasma confinement by suppressing micro-turbulence. A model-based feedback system which controls the plasma rotation profile on the National Spherical Torus Experiment (NSTX) and its upgrade (NSTX-U) is presented. The first part of this work uses experimental measurements from NSTX as a starting point and models the control of plasma rotation using two different types of actuation: momentum from injected neutral beams and neoclassical toroidal viscosity generated by three-dimensional applied magnetic fields. Whether based on the data-driven model for NSTX or purely predictive modeling for NSTX-U, a reduced order model based feedback controller was designed. Predictive simulations using the TRANSP plasma transport code with the actuator input determined by the controller (controller-in-the-loop) show that the controller drives the plasma's rotation to the desired profiles in less than 100 ms given practical constraints on the actuators and the available real-time rotation measurements. This is the first time that TRANSP has been used as a plasma in simulator in a closed feedback loop test. Another approach to control simultaneously the toroidal rotation profile as well as βN is then shown for NSTX-U. For this case, the neutral beams (actuators) have been augmented in the modeling to match the upgrade version which spread the injection throughout the edge of the plasma. Control robustness in stability and performance has then been tested and used to predict the limits of the resulting controllers when the energy confinement time (τE) and the momentum diffusivity coefficient (χϕ) vary.

High-resolution disruption halo current measurements using Langmuir probes in Alcator C-Mod

NASA Astrophysics Data System (ADS)

Tinguely, R. A.; Granetz, R. S.; Berg, A.; Kuang, A. Q.; Brunner, D.; LaBombard, B.

2018-01-01

Halo currents generated during disruptions on Alcator C-Mod have been measured with Langmuir ‘rail’ probes. These rail probes are embedded in a lower outboard divertor module in a closely-spaced vertical (poloidal) array. The dense array provides detailed resolution of the spatial dependence (~1 cm spacing) of the halo current distribution in the plasma scrape-off region with high time resolution (400 kHz digitization rate). As the plasma limits on the outboard divertor plate, the contact point is clearly discernible in the halo current data (as an inversion of current) and moves vertically down the divertor plate on many disruptions. These data are consistent with filament reconstructions of the plasma boundary, from which the edge safety factor of the disrupting plasma can be calculated. Additionally, the halo current ‘footprint’ on the divertor plate is obtained and related to the halo flux width. The voltage driving halo current and the effective resistance of the plasma region through which the halo current flows to reach the probes are also investigated. Estimations of the sheath resistance and halo region resistivity and temperature are given. This information could prove useful for modeling halo current dynamics.

Seminar on Understanding Digital Control and Analysis in Vibration Test Systems

NASA Technical Reports Server (NTRS)

1975-01-01

The advantages of the digital methods over the analog vibration methods are demonstrated. The following topics are covered: (1) methods of computer-controlled random vibration and reverberation acoustic testing, (2) methods of computer-controlled sinewave vibration testing, and (3) methods of computer-controlled shock testing. General algorithms are described in the form of block diagrams and flow diagrams.

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.

Determination of the implementation of the 3-axis attitude motion simulator digital position controller

NASA Technical Reports Server (NTRS)

Magana, Mario E.

1989-01-01

The digital position controller implemented in the control computer of the 3-axis attitude motion simulator is mathematically reconstructed and documented, since the information supplied with the executable code of this controller was insufficient to make substantial modifications to it. Also developed were methodologies to introduce changes in the controller which do not require rewriting the software. Finally, recommendations are made on possible improvement to the control system performance.

A telerobotic digital controller system

NASA Technical Reports Server (NTRS)

Brown, Richard J.

1992-01-01

This system is a network of joint mounted dual axes digital servo-controllers (DDSC), providing control of various joints and end effectors of different robotic systems. This report provides description of and user required information for the Digital Controller System Network (DSCN) and, in particular, the DDSC, Model DDSC-2, developed to perform the controller functions. The DDSC can control 3 phase brushless or brush type DC motors, requiring up to 8 amps. Only four wires, two for power and 2 for serial communication, are required, except for local sensor and motor connections. This highly capable, very flexible, programmable servo-controller, contained on a single, compact printed circuit board measuring only 4.5 x 5.1 inches, is applicable to control systems of all types from sub-arc second precision pointing to control of robotic joints and end effectors. This document concentrates on the robotic applications for the DDSC.

An overview of integrated flight-propulsion controls flight research on the NASA F-15 research airplane

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Gatlin, Donald H.; Stewart, James F.

1995-01-01

The NASA Dryden Flight Research Center has been conducting integrated flight-propulsion control flight research using the NASA F-15 airplane for the past 12 years. The research began with the digital electronic engine control (DEEC) project, followed by the F100 Engine Model Derivative (EMD). HIDEC (Highly Integrated Digital Electronic Control) became the umbrella name for a series of experiments including: the Advanced Digital Engine Controls System (ADECS), a twin jet acoustics flight experiment, self-repairing flight control system (SRFCS), performance-seeking control (PSC), and propulsion controlled aircraft (PCA). The upcoming F-15 project is ACTIVE (Advanced Control Technology for Integrated Vehicles). This paper provides a brief summary of these activities and provides background for the PCA and PSC papers, and includes a bibliography of all papers and reports from the NASA F-15 project.

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.

A method for reducing sampling jitter in digital control systems

NASA Technical Reports Server (NTRS)

Anderson, T. O.; HURBD W. J.; Hurd, W. J.

1969-01-01

Digital phase lock loop system is designed by smoothing the proportional control with a low pass filter. This method does not significantly affect the loop dynamics when the smoothing filter bandwidth is wide compared to loop bandwidth.

76 FR 62642 - Digital Broadcast Television Redistribution Control; Corrections

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-11

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 11-1432] Digital Broadcast Television Redistribution Control; Corrections AGENCY: Federal Communications Commission. ACTION: Technical amendment. SUMMARY: The Federal Communications Commission (FCC) is correcting a final rule that appeared in the...

Digital avionics: A cornerstone of aviation

NASA Technical Reports Server (NTRS)

Spitzer, Cary R.

1990-01-01

Digital avionics is continually expanding its role in communication (HF and VHF, satellite, data links), navigation (ground-based systems, inertial and satellite-based systems), and flight-by-wire control. Examples of electronic flight control system architecture, pitch, roll, and yaw control are presented. Modeling of complex hardware systems, electromagnetic interference, and software are discussed.

Proceedings of the Fourth Annual Workshop on the Use of Digital Computers in Process Control.

ERIC Educational Resources Information Center

Smith, Cecil L., Ed.

Contents: Computer hardware testing (results of vendor-user interaction); CODIL (a new language for process control programing); the design and implementation of control systems utilizing CRT display consoles; the systems contractor - valuable professional or unnecessary middle man; power station digital computer applications; from inspiration to…

Seminar on Understanding Digital Control and Analysis in Vibration Test Systems, part 2

NASA Technical Reports Server (NTRS)

1975-01-01

A number of techniques for dealing with important technical aspects of the random vibration control problem are described. These include the generation of pseudo-random and true random noise, the control spectrum estimation problem, the accuracy/speed tradeoff, and control correction strategies. System hardware, the operator-system interface, safety features, and operational capabilities of sophisticated digital random vibration control systems are also discussed.

Robust and real-time rotor control with magnetic bearings

NASA Technical Reports Server (NTRS)

Sinha, A.; Wang, K. W.; Mease, K. L.

1991-01-01

This paper deals with the sliding mode control of a rigid rotor via radial magnetic bearings. The digital control algorithm and the results from numerical simulations are presented for an experimental rig. The experimental system which has been set up to digitally implement and validate the sliding mode control algorithm is described. Two methods for the development of control softwares are presented. Experimental results for individual rotor axis are discussed.

Improvement of a Pneumatic Control Valve with Self-Holding Function

NASA Astrophysics Data System (ADS)

Dohta, Shujiro; Akagi, Tetsuya; Kobayashi, Wataru; Shimooka, So; Masago, Yusuke

2017-10-01

The purpose of this study is to develop a small-sized, lightweight and low-cost control valve with low energy consumption and to apply it to the assistive system. We have developed some control valves; a tiny on/off valve using a vibration motor, and an on/off valve with self-holding function. We have also proposed and tested the digital servo valve with self-holding function using permanent magnets and a small-sized servo motor. In this paper, in order to improve the valve, an analytical model of the digital servo valve is proposed. And the simulated results by using the analytical model and identified parameters were compared with the experimental results. Then, the improved digital servo valve was designed based on the calculated results and tested. As a result, we realized the digital servo valve that can control the flow rate more precisely while maintaining its volume and weight compared with the previous valve. As an application of the improved valve, a position control system of rubber artificial muscle was built and the position control was performed successfully.

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

Vacuum compatible miniature CCD camera head

DOEpatents

Conder, Alan D.

2000-01-01

A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

Modeling digits. Digit patterning is controlled by a Bmp-Sox9-Wnt Turing network modulated by morphogen gradients.

PubMed

Raspopovic, J; Marcon, L; Russo, L; Sharpe, J

2014-08-01

During limb development, digits emerge from the undifferentiated mesenchymal tissue that constitutes the limb bud. It has been proposed that this process is controlled by a self-organizing Turing mechanism, whereby diffusible molecules interact to produce a periodic pattern of digital and interdigital fates. However, the identities of the molecules remain unknown. By combining experiments and modeling, we reveal evidence that a Turing network implemented by Bmp, Sox9, and Wnt drives digit specification. We develop a realistic two-dimensional simulation of digit patterning and show that this network, when modulated by morphogen gradients, recapitulates the expression patterns of Sox9 in the wild type and in perturbation experiments. Our systems biology approach reveals how a combination of growth, morphogen gradients, and a self-organizing Turing network can achieve robust and reproducible pattern formation. Copyright © 2014, American Association for the Advancement of Science.

New satellite mission with old data: Rescuing a unique data set

NASA Astrophysics Data System (ADS)

Benson, Robert F.; Bilitza, Dieter

2009-02-01

We review efforts to save a unique data set and scientific results based on the rescued data. The goal of the project was to produce Alouette 2, ISIS 1, and ISIS 2 digital topside ionograms from selected original seven-track analog telemetry tapes. This project was initiated to preserve a significant portion of 60 satellite years of analog data, collected between 1962 and 1990, in digital form before the tapes were discarded. More than 1/2 million digital topside ionograms are now available for downloading at http://nssdcftp.gsfc.nasa.gov and for browsing and plotting at http://cdaweb.gsfc.nasa.gov. We illustrate data products, discuss analysis programs, review scientific results based on the digital data, and recognize those who made the project possible. The scientific results include evidence of extremely low altitude ionospheric peak densities at high latitudes, improved and new ionospheric models including one connecting the F2 topside ionosphere and the plasmasphere, transionospheric HF propagation investigations, and new interpretations of sounder-stimulated plasma emissions that have challenged theorists for decades. The homepage for the ISIS project is at http://nssdc.gsfc.nasa.gov/space/isis/isis-status.html.

Savant memory for digits in a case of synaesthesia and Asperger syndrome is related to hyperactivity in the lateral prefrontal cortex.

PubMed

Bor, Daniel; Billington, Jac; Baron-Cohen, Simon

2007-10-01

SINGLE CASE: DT is a savant with exceptional abilities in numerical memory and mathematical calculations. DT also has an elaborate form of synaesthesia for visually presented digits. Further more, DT also has Asperger syndrome (AS). We carried out two preliminary investigations to establish whether these conditions may contribute to his savant abilities. In an fMRI digit span study, DT showed hyperactivity in lateral prefrontal cortex when encoding digits, compared with controls. In addition, while controls showed raised lateral prefrontal activation in response to structured (compared to unstructured) sequences of digits, DT's neural activity did not differ between these two conditions. In addition, controls showed a significant performance advantage for structured, compared with unstructured sequences whereas no such pattern was found for DT. We suggest that this performance pattern reflects that DT focuses less on external mathematical structure, since for him all digit sequences have internal structure linked to his synaesthesia. Finally, DT did not activate extra-striate regions normally associated with synaesthesia, suggesting that he has an unusual and more abstract and conceptual form of synaesthesia. This appears to generate structured, highly-chunked content that enhances encoding of digits and aids both recall and calculation. People with AS preferentially attend to local features of stimuli. To test this in DT, we administered the Navon task. Relative to controls, DT was faster at finding a target at the local level, and was less distracted by interference from the global level. The propensity to focus on local detail, in concert with a form of synaesthesia that provides structure to all digits, may account for DT's exceptional numerical memory and calculation ability. This neural and cognitive pattern needs to be tested in a series of similar cases, and with more constrained control groups, to confirm the significance of this association.

Developing noninvasive diagnosis for single-gene disorders: the role of digital PCR.

PubMed

Barrett, Angela N; Chitty, Lyn S

2014-01-01

Cell-free fetal DNA constitutes approximately 10 % of the cell-free DNA found in maternal plasma and can be used as a reliable source of fetal genetic material for noninvasive prenatal diagnosis (NIPD) from early pregnancy. The relatively high levels of maternal background can make detection of paternally inherited point mutations challenging. Diagnosis of inheritance of autosomal recessive disorders using qPCR is even more challenging due to the high background of mutant maternal allele. Digital PCR is a very sensitive modified method of quantitative real-time PCR (qPCR), allowing absolute quantitation and rare allele detection without the need for standards or normalization. Samples are diluted and then partitioned into a large number of small qPCR reactions, some of which contain the target molecule and some which do not; the proportion of positive reactions can be used to calculate the concentration of targets in the initial sample. Here we discuss the use of digital PCR as an accurate approach to NIPD for single-gene disorders.

[Detection of KRAS mutation in colorectal cancer patients' cfDNA with droplet digital PCR].

PubMed

Luo, Yuwen; Li, Yao

2018-03-25

This study aims to develop a new method for the detection of KRAS mutations related to colorectal cancer in cfDNA, and to evaluate the sensitivity and accuracy of the detection. We designed a method of cfDNA based KRAS detection by droplets digital PCR (ddPCR). The theoretical performance of the method is evaluated by reference standard and compared to the ARMS PCR method. Two methods, ddPCR and qPCR, were successfully established to detect KRAS wild type and 7 mutants. Both methods were validated using plasmid standards and actual samples. The results were evaluated by false positive rate, linearity, and limit of detection. Finally, 52 plasma cfDNA samples from patients and 20 samples from healthy people were tested, the clinical sensitivity is 97.64%, clinical specificity is 81.43%. ddPCR method shows higher performance than qPCR. The LOD of ddPCR method reached single digits of cfDNA copies, it can detect as low as 0.01% to 0.04% mutation abundance.

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.

Control and data acquisition upgrades for NSTX-U

DOE PAGES

Davis, W. M.; Tchilinguirian, G. J.; Carroll, T.; ...

2016-06-06

The extensive NSTX Upgrade (NSTX-U) Project includes major components which allow a doubling of the toroidal field strength to 1 T, of the Neutral Beam heating power to 12 MW, and the plasma current to 2 MA, and substantial structural enhancements to withstand the increased electromagnetic loads. The maximum pulse length will go from 1.5 to 5 s. The larger and more complex forces on the coils will be protected by a Digital Coil Protection System, which requires demanding real-time data input rates, calculations and responses. The amount of conventional digitized data for a given pulse is expected to increasemore » from 2.5 to 5 GB per second of pulse. 2-D Fast Camera data is expected to go from 2.5 GB/pulse to 10, and another 2 GB/pulse is expected from new IR cameras. Our network capacity will be increased by a factor of 10, with 10 Gb/s fibers used for the major trunks. 32-core Linux systems will be used for several functions, including between-shot data processing, MDSplus data serving, between-shot EFIT analysis, real-time processing, and for a new capability, between-shot TRANSP. As a result, improvements to the MDSplus events subsystem will be made through the use of both UDP and TCP/IP based methods and the addition of a dedicated “event server”.« less

ERPs and oscillations during encoding predict retrieval of digit memory in superior mnemonists.

PubMed

Pan, Yafeng; Li, Xianchun; Chen, Xi; Ku, Yixuan; Dong, Yujie; Dou, Zheng; He, Lin; Hu, Yi; Li, Weidong; Zhou, Xiaolin

2017-10-01

Previous studies have consistently demonstrated that superior mnemonists (SMs) outperform normal individuals in domain-specific memory tasks. However, the neural correlates of memory-related processes remain unclear. In the current EEG study, SMs and control participants performed a digit memory task during which their brain activity was recorded. Chinese SMs used a digit-image mnemonic for encoding digits, in which they associated 2-digit groups with images immediately after the presentation of each even-position digit in sequences. Behaviorally, SMs' memory of digit sequences was better than the controls'. During encoding in the study phase, SMs showed an increased right central P2 (150-250ms post onset) and a larger right posterior high-alpha (10-14Hz, 500-1720ms) oscillation on digits at even-positions compared with digits at odd-positions. Both P2 and high-alpha oscillations in the study phase co-varied with performance in the recall phase, but only in SMs, indicating that neural dynamics during encoding could predict successful retrieval of digit memory in SMs. Our findings suggest that representation of a digit sequence in SMs using mnemonics may recruit both the early-stage attention allocation process and the sustained information preservation process. This study provides evidence for the role of dynamic and efficient neural encoding processes in mnemonists. Copyright © 2017. Published by Elsevier Inc.

Design of a digital holography system for PFC erosion measurements on Proto-MPEX

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

ThomasJr., C. E.; Biewer, Theodore M; Baylor, Larry R

2016-01-01

A project has been started at ORNL to develop a dual-wavelength digital holography system for plasma facing component (PFC) erosion measurements on Proto-MPEX. Such a system will allow in-situ real-time measurements of component erosion. Initially the system will be developed with one laser, and first experimental laboratory measurements will be made with the single laser system. In the second year of development a second CO2 laser will be added and measurements with the dual wavelength system will begin. Adding the second wavelength allows measurements at a much longer synthetic wavelength equal to the average of the two wavelengths times themore » average divided by the difference of the two wavelengths.« less

Fast neutron flux analyzer with real-time digital pulse shape discrimination

NASA Astrophysics Data System (ADS)

Ivanova, A. A.; Zubarev, P. V.; Ivanenko, S. V.; Khilchenko, A. D.; Kotelnikov, A. I.; Polosatkin, S. V.; Puryga, E. A.; Shvyrev, V. G.; Sulyaev, Yu. S.

2016-08-01

Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL-3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL-3 and GDT devices. This analyzer was tested and calibrated with the help of 137Cs and 252Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented.

Software control and system configuration management - A process that works

NASA Technical Reports Server (NTRS)

Petersen, K. L.; Flores, C., Jr.

1983-01-01

A comprehensive software control and system configuration management process for flight-crucial digital control systems of advanced aircraft has been developed and refined to insure efficient flight system development and safe flight operations. Because of the highly complex interactions among the hardware, software, and system elements of state-of-the-art digital flight control system designs, a systems-wide approach to configuration control and management has been used. Specific procedures are implemented to govern discrepancy reporting and reconciliation, software and hardware change control, systems verification and validation testing, and formal documentation requirements. An active and knowledgeable configuration control board reviews and approves all flight system configuration modifications and revalidation tests. This flexible process has proved effective during the development and flight testing of several research aircraft and remotely piloted research vehicles with digital flight control systems that ranged from relatively simple to highly complex, integrated mechanizations.

Software control and system configuration management: A systems-wide approach

NASA Technical Reports Server (NTRS)

Petersen, K. L.; Flores, C., Jr.

1984-01-01

A comprehensive software control and system configuration management process for flight-crucial digital control systems of advanced aircraft has been developed and refined to insure efficient flight system development and safe flight operations. Because of the highly complex interactions among the hardware, software, and system elements of state-of-the-art digital flight control system designs, a systems-wide approach to configuration control and management has been used. Specific procedures are implemented to govern discrepancy reporting and reconciliation, software and hardware change control, systems verification and validation testing, and formal documentation requirements. An active and knowledgeable configuration control board reviews and approves all flight system configuration modifications and revalidation tests. This flexible process has proved effective during the development and flight testing of several research aircraft and remotely piloted research vehicles with digital flight control systems that ranged from relatively simple to highly complex, integrated mechanizations.

New advanced netted ground based and topside radio diagnostics for Space Weather Program

NASA Astrophysics Data System (ADS)

Rothkaehl, Hanna; Krankowski, Andrzej; Morawski, Marek; Atamaniuk, Barbara; Zakharenkova, Irina; Cherniak, Iurii

2014-05-01

To give a more detailed and complete understanding of physical plasma processes that govern the solar-terrestrial space, and to develop qualitative and quantitative models of the magnetosphere-ionosphere-thermosphere coupling, it is necessary to design and build the next generation of instruments for space diagnostics and monitoring. Novel ground- based wide-area sensor networks, such as the LOFAR (Low Frequency Array) radar facility, comprising wide band, and vector-sensing radio receivers and multi-spacecraft plasma diagnostics should help solve outstanding problems of space physics and describe long-term environmental changes. The LOw Frequency ARray - LOFAR - is a new fully digital radio telescope designed for frequencies between 30 MHz and 240 MHz located in Europe. The three new LOFAR stations will be installed until summer 2015 in Poland. The LOFAR facilities in Poland will be distributed among three sites: Lazy (East of Krakow), Borowiec near Poznan and Baldy near Olsztyn. All they will be connected via PIONIER dedicated links to Poznan. Each site will host one LOFAR station (96 high-band+96 low-band antennas). They will most time work as a part of European network, however, when less charged, they can operate as a national network The new digital radio frequency analyzer (RFA) on board the low-orbiting RELEC satellite was designed to monitor and investigate the ionospheric plasma properties. This two-point ground-based and topside ionosphere-located space plasma diagnostic can be a useful new tool for monitoring and diagnosing turbulent plasma properties. The RFA on board the RELEC satellite is the first in a series of experiments which is planned to be launched into the near-Earth environment. In order to improve and validate the large scales and small scales ionospheric structures we will used the GPS observations collected at IGS/EPN network employed to reconstruct diurnal variations of TEC using all satellite passes over individual GPS stations and the data retrieved from FORMOSAT-3/COSMIC radio occultation measurements. The main purpose of this presentation is to describe new advanced diagnostic techniques of the near-Earth space plasma and point out the scientific challenges of the radio frequency analyser located on board of low orbiting satellites and LOFAR facilities. This research is partly supported by grant O N517 418440

Quantification and Dynamic Monitoring of EGFR T790M in Plasma Cell-Free DNA by Digital PCR for Prognosis of EGFR-TKI Treatment in Advanced NSCLC

PubMed Central

Wang, Zhijie; Chen, Rui; Wang, Shuhang; Zhong, Jia; Wu, Meina; Zhao, Jun; Duan, Jianchun; Zhuo, Minglei; An, Tongtong; Wang, Yuyan; Bai, Hua; Wang, Jie

2014-01-01

Background Among advanced non-small cell lung cancer (NSCLC) patients with an acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI), about 50% carry the T790M mutation, but this frequency in EGFR-TKI-naïve patients and dynamic change during therapy remains unclear. This study investigated the quantification and dynamic change of T790M mutation in plasma cell-free DNA (cf-DNA) of advanced NSCLC patients to assess the clinical outcomes of EGFR-TKI therapy. Materials and Methods We retrospectively investigated 135 patients with advanced NSCLC who obtained progression-free survival (PFS) after EGFR-TKI for >6 months for their EGFR sensitive mutations and T790M mutation in matched pre- and post-TKI plasma samples, using denaturing high-performance liquid chromatography (DHPLC), amplification refractory mutation system (ARMS), and digital-PCR (D-PCR). Real-time PCR was performed to measure c-MET amplification. Results Detection limit of D-PCR in assessing the T790M mutation was approximately 0.03%. D-PCR identified higher frequency of T790M than ARMS in pre-TKI (31.3% vs. 5.5%) and post-TKI (43.0% vs. 25.2%) plasma samples. Patients with pre-TKI T790M showed inferior PFS (8.9 vs. 12.1 months, p = 0.007) and overall survival (OS, 19.3 vs. 31.9 months, p = 0.001) compared with those without T790M. In patients harboring EGFR sensitive mutation, high quantities of pre-TKI T790M predicted poorer PFS (p = 0.001) on EGFR-TKI than low ones. Moreover, patients who experienced increased quantity of T790M during EGFR-TKI treatment showed superior PFS and OS compared with those with decreased changes (p = 0.044 and p = 0.015, respectively). Conclusion Qualitative and quantitative T790M in plasma cf-DNA by D-PCR provided a non-invasive and sensitive assay to predict EGFR-TKI prognosis. PMID:25405807

Active stabilization of a rapidly chirped laser by an optoelectronic digital servo-loop control.

PubMed

Gorju, G; Jucha, A; Jain, A; Crozatier, V; Lorgeré, I; Le Gouët, J-L; Bretenaker, F; Colice, M

2007-03-01

We propose and demonstrate a novel active stabilization scheme for wide and fast frequency chirps. The system measures the laser instantaneous frequency deviation from a perfectly linear chirp, thanks to a digital phase detection process, and provides an error signal that is used to servo-loop control the chirped laser. This way, the frequency errors affecting a laser scan over 10 GHz on the millisecond timescale are drastically reduced below 100 kHz. This active optoelectronic digital servo-loop control opens new and interesting perspectives in fields where rapidly chirped lasers are crucial.

Interface For Fault-Tolerant Control System

NASA Technical Reports Server (NTRS)

Shaver, Charles; Williamson, Michael

1989-01-01

Interface unit and controller emulator developed for research on electronic helicopter-flight-control systems equipped with artificial intelligence. Interface unit interrupt-driven system designed to link microprocessor-based, quadruply-redundant, asynchronous, ultra-reliable, fault-tolerant control system (controller) with electronic servocontrol unit that controls set of hydraulic actuators. Receives digital feedforward messages from, and transmits digital feedback messages to, controller through differential signal lines or fiber-optic cables (thus far only differential signal lines have been used). Analog signals transmitted to and from servocontrol unit via coaxial cables.

Programmable Digital Controller

NASA Technical Reports Server (NTRS)

Wassick, Gregory J.

2012-01-01

An existing three-channel analog servo loop controller has been redesigned for piezoelectric-transducer-based (PZT-based) etalon control applications to a digital servo loop controller. This change offers several improvements over the previous analog controller, including software control over proportional-integral-derivative (PID) parameters, inclusion of other data of interest such as temperature and pressure in the control laws, improved ability to compensate for PZT hysteresis and mechanical mount fluctuations, ability to provide pre-programmed scanning and stepping routines, improved user interface, expanded data acquisition, and reduced size, weight, and power.

Motion and Form Coherence Detection in Autistic Spectrum Disorder: Relationship to Motor Control and 2:4 Digit Ratio

ERIC Educational Resources Information Center

Milne, Elizabeth; White, Sarah; Campbell, Ruth; Swettenham, John; Hansen, Peter; Ramus, Franck

2006-01-01

Children with autistic spectrum disorder and controls performed tasks of coherent motion and form detection, and motor control. Additionally, the ratio of the 2nd and 4th digits of these children, which is thought to be an indicator of foetal testosterone, was measured. Children in the experimental group were impaired at tasks of motor control,…

Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine digital control system design report

NASA Technical Reports Server (NTRS)

1978-01-01

A digital electronic control was combined with conventional hydromechanical components to operate the four controlled variables on the under-the-wing engine: fuel flow, fan blade pitch, fan exhaust area, and core compressor stator angles. The engine and control combination offers improvements in noise, pollution, thrust response, operational monitoring, and pilot workload relative to current engines.

USB video image controller used in CMOS image sensor

NASA Astrophysics Data System (ADS)

Zhang, Wenxuan; Wang, Yuxia; Fan, Hong

2002-09-01

CMOS process is mainstream technique in VLSI, possesses high integration. SE402 is multifunction microcontroller, which integrates image data I/O ports, clock control, exposure control and digital signal processing into one chip. SE402 reduces the number of chips and PCB's room. The paper studies emphatically on USB video image controller used in CMOS image sensor and give the application on digital still camera.

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.

Effect of various features on the life cycle cost of the timing/synchronization subsystem of the DCS digital communications network

NASA Technical Reports Server (NTRS)

Kimsey, D. B.

1978-01-01

The effect on the life cycle cost of the timing subsystem was examined, when these optional features were included in various combinations. The features included mutual control, directed control, double-ended reference links, independence of clock error measurement and correction, phase reference combining, self-organization, smoothing for link and nodal dropouts, unequal reference weightings, and a master in a mutual control network. An overall design of a microprocessor-based timing subsystem was formulated. The microprocessor (8080) implements the digital filter portion of a digital phase locked loop, as well as other control functions such as organization of the network through communication with processors at neighboring nodes.

Application of digital control to a magnetic model suspension and balance model

NASA Technical Reports Server (NTRS)

Luh, P. B.; Covert, E. E.; Whitaker, H. P.; Haldeman, C. W.

1978-01-01

The feasibility of using a digital computer for performing the automatic control functions for a magnetic suspension and balance system (MSBS) for use with wind tunnel models was investigated. Modeling was done using both a prototype MSBS and a one dimensional magnetic balance. A microcomputer using the Intel 8080 microprocessor is described and results are given using this microprocessor to control the one dimensional balance. Hybrid simulations for one degree of freedom of the MSBS were also performed and are reported. It is concluded that use of a digital computer to control the MSBS is eminently feasible and should extend both the accuracy and utility of the system.

Evaluation of Digital Technology and Software Use among Business Education Teachers

ERIC Educational Resources Information Center

Ellis, Richard S.; Okpala, Comfort O.

2004-01-01

Digital video cameras are part of the evolution of multimedia digital products that have positive applications for educators, students, and industry. Multimedia digital video can be utilized by any personal computer and it allows the user to control, combine, and manipulate different types of media, such as text, sound, video, computer graphics,…

Visual Design Guidelines for Improving Learning from Dynamic and Interactive Digital Text

ERIC Educational Resources Information Center

Jin, Sung-Hee

2013-01-01

Despite the dynamic and interactive features of digital text, the visual design guidelines for digital text are similar to those for printed text. The purpose of this study was to develop visual design guidelines for improving learning from dynamic and interactive digital text and to validate them by controlled testing. Two structure design…

A self-adaptive metamaterial beam with digitally controlled resonators for subwavelength broadband flexural wave attenuation

NASA Astrophysics Data System (ADS)

Li, Xiaopeng; Chen, Yangyang; Hu, Gengkai; Huang, Guoliang

2018-04-01

Designing lightweight materials and/or structures for broadband low-frequency noise/vibration mitigation is an issue of fundamental importance both practically and theoretically. In this paper, by leveraging the concept of frequency-dependent effective stiffness control, we numerically and experimentally demonstrate, for the first time, a self-adaptive metamaterial beam with digital circuit controlled mechanical resonators for strong and broadband flexural wave attenuation at subwavelength scales. The digital controllers that are capable of feedback control of piezoelectric shunts are integrated into mechanical resonators in the metamaterial, and the transfer function is semi-analytically determined to realize an effective bending stiffness in a quadratic function of the wave frequency for adaptive band gaps. The digital as well as analog control circuits as the backbone of the system are experimentally realized with the guarantee stability of the whole electromechanical system in whole frequency regions, which is the most challenging problem so far. Our experimental results are in good agreement with numerical predictions and demonstrate the strong wave attenuation in almost a three times larger frequency region over the bandwidth of a passive metamaterial. The proposed metamaterial could be applied in a range of applications in the design of elastic wave control devices.

Digital control algorithms for microgravity isolation systems

NASA Technical Reports Server (NTRS)

Sinha, Alok; Wang, Yung-Peng

1992-01-01

New digital control algorithms were developed to achieve the desired acceleration transmissibility function. The attractive electromagnets have been taken as actuators. The relative displacement and the acceleration of the mass were used as feedback signals. Two approaches were developed to find that controller transfer function in Z-domain, which yields the desired transmissibility at each frequency. In the first approach, the controller transfer function is obtained by assuming that the desired transmissibility is known in Z-domain. Since the desired transmissibility H sub d(S) = 1/(tauS+1)(exp 2) is given in S-domain, the first task is to obtain the desired transmissibility in Z-domain. There are three methods to perform this task: bilinear transformation, and backward and forward rectangular rules. The bilinear transformation and backward rectangular rule lead to improper controller transfer functions, which are physically not realizable. The forward rectangular rule does lead to a physically realizable controller. However, this controller is found to be marginally stable because of a pole at Z=1. In order to eliminate this pole, a hybrid control structure is proposed. Here the control input is composed of two parts: analog and digital. The analog input simply represents the velocity (or the integral of acceleration) feedback; and the digital controller which uses only relative displacement signal, is then obtained to achieve the desired closed-loop transfer function. The stability analysis indicates that the controller transfer function is stable for typical values of sampling period. In the second approach, the aforementioned hybrid control structure is again used. First, an analog controller transfer function corresponding to relative displacement feedback is obtained to achieve the transmissibility as 1/(tauS+1)(exp 2). Then the transfer function for the digital control input is obtained by discretizing this analog controller transfer function via bilinear transformation. The stability of the resulting Z-domain closed loop system is analyzed. Also, the frequency response of the Z-domain closed-loop transfer function is determined to evaluate the performance of the control system.

Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

NASA Astrophysics Data System (ADS)

Meng, Jianbing; Dong, Xiaojuan; Wei, Xiuting; Yin, Zhanmin

2014-03-01

Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM), a Fourier-transform infrared spectrophotometer (FTIR), an X-ray diffractometer (XRD), an optical contact angle meter, a digital Vickers micro-hardness (Hv) tester, and electronic universal testing. The results show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.

Preparation of anti-adhesion surfaces on aluminium substrates of rubber plastic moulds using a coupling method of liquid plasma and electrochemical machining

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

Meng, Jianbing, E-mail: jianbingmeng@126.com; Dong, Xiaojuan; Wei, Xiuting

Hard anti-adhesion surfaces, with low roughness and wear resistance, on aluminium substrates of rubber plastic moulds were fabricated via a new coupling method of liquid plasma and electrochemical machining. With the aid of liquid plasma thermal polishing and electrochemical anodic dissolution, micro/nano-scale binary structures were prepared as the base of the anti-adhesion surfaces. The anti-adhesion behaviours of the resulting aluminium surfaces were analysed by a surface roughness measuring instrument, a scanning electron microscope (SEM), a Fourier-transform infrared spectrophotometer (FTIR), an X-ray diffractometer (XRD), an optical contact angle meter, a digital Vickers micro-hardness (Hv) tester, and electronic universal testing. The resultsmore » show that, after the liquid plasma and electrochemical machining, micro/nano-scale binary structures composed of micro-scale pits and nano-scale elongated boss structures were present on the sample surfaces. As a result, the anti-adhesion surfaces fabricated by the above coupling method have good anti-adhesion properties, better wear resistance and lower roughness.« less

Theoretical and experimental zonal drift velocities of the ionospheric plasma bubbles over the Brazilian region

NASA Astrophysics Data System (ADS)

Arruda, Daniela C. S.; Sobral, J. H. A.; Abdu, M. A.; Castilho, Vivian M.; Takahashi, H.; Medeiros, A. F.; Buriti, R. A.

2006-01-01

This work presents equatorial ionospheric plasma bubble zonal drift velocity observations and their comparison with model calculations. The bubble zonal velocities were measured using airglow OI630 nm all-sky digital images and the model calculations were performed taking into account flux-tube integrated Pedersen conductivity and conductivity weighted neutral zonal winds. The digital images were obtained from an all-sky imaging system operated over the low-latitude station Cachoeira Paulista (Geogr. 22.5S, 45W, dip angle 31.5S) during the period from October 1998 to August 2000. Out of the 138 nights of imager observation, 29 nights with the presence of plasma bubbles are used in this study. These 29 nights correspond to geomagnetically rather quiet days (∑K P < 24+) and were grouped according to season. During the early night hours, the calculated zonal drift velocities were found to be larger than the experimental values. The best matching between the calculated and observed zonal velocities were seen to be for a few hours around midnight. The model calculation showed two humps around 20 LT and 24 LT that were not present in the data. Average decelerations obtained from linear regression between 20 LT and 24 LT were found to be: (a) Spring 1998, -8.61 ms -1 h -1; (b) Summer 1999, -0.59 ms -1 h -1; (c) Spring 1999, -11.72 ms -1 h -1; and (d) Summer 2000, -8.59 ms -1 h -1. Notice that Summer and Winter here correspond to southern hemisphere Summer and Winter, not northern hemisphere.

Multiplex Preamplification of Serum DNA to Facilitate Reliable Detection of Extremely Rare Cancer Mutations in Circulating DNA by Digital PCR.

PubMed

Jackson, Jennifer B; Choi, Daniel S; Luketich, James D; Pennathur, Arjun; Ståhlberg, Anders; Godfrey, Tony E

2016-03-01

Tumor-specific mutations can be identified in circulating, cell-free DNA in plasma or serum and may serve as a clinically relevant alternative to biopsy. Detection of tumor-specific mutations in the plasma, however, is technically challenging. First, mutant allele fractions are typically low in a large background of wild-type circulating, cell-free DNA. Second, the amount of circulating, cell-free DNA acquired from plasma is also low. Even when using digital PCR (dPCR), rare mutation detection is challenging because there is not enough circulating, cell-free DNA to run technical replicates and assay or instrument noise does not easily allow for mutation detection <0.1%. This study was undertaken to improve on the robustness of dPCR for mutation detection. A multiplexed, preamplification step using a high-fidelity polymerase before dPCR was developed to increase total DNA and the number of targets and technical replicates that can be assayed from a single sample. We were able to detect multiple cancer-relevant mutations within tumor-derived samples down to 0.01%. Importantly, the signal/noise ratio was improved for all preamplified targets, allowing for easier discrimination of low-abundance mutations against false-positive signal. Furthermore, we used this protocol on clinical samples to detect known, tumor-specific mutations in patient sera. This study provides a protocol for robust, sensitive detection of circulating tumor DNA for future clinical applications. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Advanced X-ray Imaging Crystal Spectrometer for Magnetic Fusion Tokamak Devices

NASA Astrophysics Data System (ADS)

Lee, S. G.; Bak, J. G.; Bog, M. G.; Nam, U. W.; Moon, M. K.; Cheon, J. K.

2008-03-01

An advanced X-ray imaging crystal spectrometer is currently under development using a segmented position sensitive detector and time-to-digital converter (TDC) based delay-line readout electronics for burning plasma diagnostics. The proposed advanced XICS utilizes an eight-segmented position sensitive multi-wire proportional counter and supporting electronics to increase the spectrometer performance includes the photon count-rate capability and spatial resolution.

Short communication: Efficacy of copper sulfate hoof baths against digital dermatitis--Where is the evidence?

PubMed

Thomsen, Peter T

2015-04-01

Digital dermatitis is a major problem in modern dairy production because of decreased animal welfare and financial losses. Individual cow treatments are often seen as too time consuming by farmers, and walk-through hoof baths have therefore been used extensively to control digital dermatitis. For decades, copper sulfate hoof baths have been used to treat and prevent digital dermatitis. Copper sulfate has been referred to as the industry gold standard when it comes to hoof-bath chemicals. In several scientific studies testing the efficacy of other hoof-care products, copper sulfate has been used as a positive control, thereby indicating that copper sulfate has a known positive effect. However, this may not be the case. A dilemma may exist between (1) copper sulfate generally being perceived as being effective against digital dermatitis and (2) a possible lack of well-documented scientific evidence of this effect. The objective of this study was to evaluate the existing scientific literature to determine whether the efficacy of copper sulfate used in hoof baths against digital dermatitis has in fact been demonstrated scientifically. A systematic literature search identified 7 peer-reviewed journal articles describing the efficacy of copper sulfate in hoof baths as treatment or prevention of bovine digital dermatitis. Only 2 of the 7 studies compared copper sulfate to a negative control; most studies were relatively small, and often no clear positive effect of copper sulfate was demonstrated. In conclusion, the frequent claim that copper sulfate is widely reported to be effective is supported by little scientific evidence. Well-designed clinical trials evaluating the effect of copper sulfate against digital dermatitis compared with a negative control are needed. Until such studies have been made, the efficacy of copper sulfate in hoof baths against digital dermatitis remains largely unproven. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Preliminary development of digital signal processing in microwave radiometers

NASA Technical Reports Server (NTRS)

Stanley, W. D.

1980-01-01

Topics covered involve a number of closely related tasks including: the development of several control loop and dynamic noise model computer programs for simulating microwave radiometer measurements; computer modeling of an existing stepped frequency radiometer in an effort to determine its optimum operational characteristics; investigation of the classical second order analog control loop to determine its ability to reduce the estimation error in a microwave radiometer; investigation of several digital signal processing unit designs; initiation of efforts to develop required hardware and software for implementation of the digital signal processing unit; and investigation of the general characteristics and peculiarities of digital processing noiselike microwave radiometer signals.

A Spectrum of Interoperability: The Site for Science Prototype for the NSDL; Re-Inventing the Wheel? Standards, Interoperability and Digital Cultural Content; Preservation Risk Management for Web Resources: Virtual Remote Control in Cornell's Project Prism; Safekeeping: A Cooperative Approach to Building a Digital Preservation Resource; Object Persistence and Availability in Digital Libraries; Illinois Digital Cultural Heritage Community-Collaborative Interactions among Libraries, Museums and Elementary Schools.

ERIC Educational Resources Information Center

Arms, William Y.; Hillmann, Diane; Lagoze, Carl; Krafft, Dean; Marisa, Richard; Saylor, John; Terizzi, Carol; Van de Sompel, Herbert; Gill, Tony; Miller, Paul; Kenney, Anne R.; McGovern, Nancy Y.; Botticelli, Peter; Entlich, Richard; Payette, Sandra; Berthon, Hilary; Thomas, Susan; Webb, Colin; Nelson, Michael L.; Allen, B. Danette; Bennett, Nuala A.; Sandore, Beth; Pianfetti, Evangeline S.

2002-01-01

Discusses digital libraries, including interoperability, metadata, and international standards; Web resource preservation efforts at Cornell University; digital preservation at the National Library of Australia; object persistence and availability; collaboration among libraries, museums and elementary schools; Asian digital libraries; and a Web…

Qualification of the flight-critical AFTI/F-16 digital flight control system. [Advanced Fighter Technology Integration

NASA Technical Reports Server (NTRS)

Mackall, D. A.; Ishmael, S. D.; Regenie, V. A.

1983-01-01

Qualification considerations for assuring the safety of a life-critical digital flight control system include four major areas: systems interactions, verification, validation, and configuration control. The AFTI/F-16 design, development, and qualification illustrate these considerations. In this paper, qualification concepts, procedures, and methodologies are discussed and illustrated through specific examples.

Automatic Exposure Control Device for Digital Mammography

DTIC Science & Technology

2001-08-01

developing innovative approaches for controlling DM exposures. These approaches entail using the digital detector and an artificial neural network to...of interest that determine the exposure parameters for the fully exposed image; and (2) to use an artificial neural network to select exposure

Automatic Exposure Control Device for Digital Mammography

DTIC Science & Technology

2004-08-01

developing innovative approaches for controlling DM exposures. These approaches entail using the digital detector and an artificial neural network to...of interest that determine the exposure parameters for the fully exposed image; and (2) to use an artificial neural network to select exposure

Method and apparatus for data decoding and processing

DOEpatents

Hunter, Timothy M.; Levy, Arthur J.

1992-01-01

A system and technique is disclosed for automatically controlling the decoding and digitizaiton of an analog tape. The system includes the use of a tape data format which includes a plurality of digital codes recorded on the analog tape in a predetermined proximity to a period of recorded analog data. The codes associated with each period of analog data include digital identification codes prior to the analog data, a start of data code coincident with the analog data recording, and an end of data code subsequent to the associated period of recorded analog data. The formatted tape is decoded in a processing and digitization system which includes an analog tape player coupled to a digitizer to transmit analog information from the recorded tape over at least one channel to the digitizer. At the same time, the tape player is coupled to a decoder and interface system which detects and decodes the digital codes on the tape corresponding to each period of recorded analog data and controls tape movement and digitizer initiation in response to preprogramed modes. A host computer is also coupled to the decoder and interface system and the digitizer and programmed to initiate specific modes of data decoding through the decoder and interface system including the automatic compilation and storage of digital identification information and digitized data for the period of recorded analog data corresponding to the digital identification data, compilation and storage of selected digitized data representing periods of recorded analog data, and compilation of digital identification information related to each of the periods of recorded analog data.

Reorganization of the raccoon cuneate nucleus after peripheral denervation.

PubMed

Rasmusson, D D; Northgrave, S A

1997-12-01

The effects of peripheral nerve transection on the cuneate nucleus were studied in anesthetized raccoons using extracellular, single-unit recordings. The somatotopic organization of the cuneate nucleus first was examined in intact, control animals. The cuneate nucleus in the raccoon is organized with the digits represented in separate cell clusters. The dorsal cap region of the cuneate nucleus contains a representation of the claws and hairy skin of the digits. Within the representation of the glabrous skin, neurons with rapidly adapting properties tended to be segregated from those with slowly adapting properties. The representations of the distal and proximal pads on a digit also were segregated. Electrical stimulation of two adjacent digits provided a detailed description of the responses originating from the digit that contains the tactile receptive field (the on-focus digit) and from the adjacent (off-focus) digit. Stimulation of the on-focus digit produced a short latency excitation in all 99 neurons tested, with a mean of 10.5 ms. These responses had a low threshold (426 microA). Stimulation of an off-focus digit activated 65% of these neurons. These responses had a significantly longer latency (15.3 ms) than on-focus responses and the threshold was more than twice as large. Two to five months after amputation of digit 4, 97 cells were tested with stimulation of digits 3 and 5. A total of 44 were in the intact regions of the cuneate nucleus. They had small receptive fields on intact digits and their responses to electrical stimulation did not differ from the control neurons. The remaining 53 neurons were judged to be deafferented and in the fourth digit region on the basis of their location with respect to intact neurons. All but two of these cells had receptive fields that were much larger than normal, often including more than one digit and part of the palm. When compared with the off-focus control neurons, their responses to electrical stimulation had lower thresholds and an increased response probability and magnitude. The latencies of these cells did not decrease, however, and were the same as the off-focus control values. The enhanced responses of the deafferented neurons to adjacent digit stimulation indicate that there is a strengthening of synapses that were previously ineffective. The increased proportion of neurons that could be activated after amputation suggests that there is also a growth of new connections. This experiment demonstrates that reorganization in the adult somatotopic system does occur at the level of the dorsal column nuclei. As a consequence, many of the changes reported at the cortex and thalamus may be due to the changes occurring at this first synapse in the somatosensory pathway.

The tracking performance of distributed recoverable flight control systems subject to high intensity radiated fields

NASA Astrophysics Data System (ADS)

Wang, Rui

It is known that high intensity radiated fields (HIRF) can produce upsets in digital electronics, and thereby degrade the performance of digital flight control systems. Such upsets, either from natural or man-made sources, can change data values on digital buses and memory and affect CPU instruction execution. HIRF environments are also known to trigger common-mode faults, affecting nearly-simultaneously multiple fault containment regions, and hence reducing the benefits of n-modular redundancy and other fault-tolerant computing techniques. Thus, it is important to develop models which describe the integration of the embedded digital system, where the control law is implemented, as well as the dynamics of the closed-loop system. In this dissertation, theoretical tools are presented to analyze the relationship between the design choices for a class of distributed recoverable computing platforms and the tracking performance degradation of a digital flight control system implemented on such a platform while operating in a HIRF environment. Specifically, a tractable hybrid performance model is developed for a digital flight control system implemented on a computing platform inspired largely by the NASA family of fault-tolerant, reconfigurable computer architectures known as SPIDER (scalable processor-independent design for enhanced reliability). The focus will be on the SPIDER implementation, which uses the computer communication system known as ROBUS-2 (reliable optical bus). A physical HIRF experiment was conducted at the NASA Langley Research Center in order to validate the theoretical tracking performance degradation predictions for a distributed Boeing 747 flight control system subject to a HIRF environment. An extrapolation of these results for scenarios that could not be physically tested is also presented.

The instrument control unit of SPICA SAFARI: a macro-unit to host all the digital control functionalities of the spectrometer

NASA Astrophysics Data System (ADS)

Di Giorgio, Anna Maria; Biondi, David; Saggin, Bortolino; Shatalina, Irina; Viterbini, Maurizio; Giusi, Giovanni; Liu, Scige J.; Cerulli-Irelli, Paquale; Van Loon, Dennis; Cara, Christophe

2012-09-01

We present the preliminary design of the Instrument Control Unit (ICU) of the SpicA FAR infrared Instrument (SAFARI), an imaging Fourier Transform Spectrometer (FTS) designed to give continuous wavelength coverage in both photometric and spectroscopic modes from around 34 to 210 µm. Due to the stringent requirements in terms of mass and volume, the overall SAFARI warm electronics will be composed by only two main units: Detector Control Unit and ICU. ICU is therefore a macro-unit incorporating the four digital sub-units dedicated to the control of the overall instrument functionalities: the Cooler Control Unit, the Mechanism Control Unit, the Digital processing Unit and the Power Supply Unit. Both the mechanical solution adopted to host the four sub-units and the internal electrical architecture are presented as well as the adopted redundancy approach.

New evidence that a large proportion of human blood plasma cell-free DNA is localized in exosomes

PubMed Central

Jiang, Chao; Krzyzanowski, Gary D.; Ryan, Wayne L.

2017-01-01

Cell-free DNA (cfDNA) in blood is used as a source of genetic material for noninvasive prenatal and cancer diagnostic assays in clinical practice. Recently we have started a project for new biomarker discovery with a view to developing new noninvasive diagnostic assays. While reviewing literature, it was found that exosomes may be a rich source of biomarkers, because exosomes play an important role in human health and disease. While characterizing exosomes found in human blood plasma, we observed the presence of cfDNA in plasma exosomes. Plasma was obtained from blood drawn into K3EDTA tubes. Exosomes were isolated from cell-free plasma using a commercially available kit. Sizing and enumeration of exosomes were done using electron microscopy and NanoSight particle counter. NanoSight and confocal microscopy was used to demonstrate the association between dsDNA and exosomes. DNA extracted from plasma and exosomes was measured by a fluorometric method and a droplet digital PCR (ddPCR) method. Size of extracellular vesicles isolated from plasma was heterogeneous and showed a mean value of 92.6 nm and a mode 39.7 nm. A large proportion of extracellular vesicles isolated from plasma were identified as exosomes using a fluorescence probe specific for exosomes and three protein markers, Hsp70, CD9 and CD63, that are commonly used to identify exosome fraction. Fluorescence dye that stain dsDNA showed the association between exosomes and dsDNA. Plasma cfDNA concentration analysis showed more than 93% of amplifiable cfDNA in plasma is located in plasma exosomes. Storage of a blood sample showed significant increases in exosome count and exosome DNA concentration. This study provide evidence that a large proportion of plasma cfDNA is localized in exosomes. Exosome release from cells is a metabolic energy dependent process, thus suggesting active release of cfDNA from cells as a source of cfDNA in plasma. PMID:28850588

New evidence that a large proportion of human blood plasma cell-free DNA is localized in exosomes.

PubMed

Fernando, M Rohan; Jiang, Chao; Krzyzanowski, Gary D; Ryan, Wayne L

2017-01-01

Cell-free DNA (cfDNA) in blood is used as a source of genetic material for noninvasive prenatal and cancer diagnostic assays in clinical practice. Recently we have started a project for new biomarker discovery with a view to developing new noninvasive diagnostic assays. While reviewing literature, it was found that exosomes may be a rich source of biomarkers, because exosomes play an important role in human health and disease. While characterizing exosomes found in human blood plasma, we observed the presence of cfDNA in plasma exosomes. Plasma was obtained from blood drawn into K3EDTA tubes. Exosomes were isolated from cell-free plasma using a commercially available kit. Sizing and enumeration of exosomes were done using electron microscopy and NanoSight particle counter. NanoSight and confocal microscopy was used to demonstrate the association between dsDNA and exosomes. DNA extracted from plasma and exosomes was measured by a fluorometric method and a droplet digital PCR (ddPCR) method. Size of extracellular vesicles isolated from plasma was heterogeneous and showed a mean value of 92.6 nm and a mode 39.7 nm. A large proportion of extracellular vesicles isolated from plasma were identified as exosomes using a fluorescence probe specific for exosomes and three protein markers, Hsp70, CD9 and CD63, that are commonly used to identify exosome fraction. Fluorescence dye that stain dsDNA showed the association between exosomes and dsDNA. Plasma cfDNA concentration analysis showed more than 93% of amplifiable cfDNA in plasma is located in plasma exosomes. Storage of a blood sample showed significant increases in exosome count and exosome DNA concentration. This study provide evidence that a large proportion of plasma cfDNA is localized in exosomes. Exosome release from cells is a metabolic energy dependent process, thus suggesting active release of cfDNA from cells as a source of cfDNA in plasma.

TECHNICAL DESIGN NOTE: Digital proportional-integral-derivative velocity controller of a Mössbauer spectrometer

NASA Astrophysics Data System (ADS)

Pechousek, J.; Prochazka, R.; Mashlan, M.; Jancik, D.; Frydrych, J.

2009-01-01

The digital proportional-integral-derivative (PID) velocity controller used in the Mössbauer spectrometer implemented in field programmable gate array (FPGA) is based on the National Instruments CompactRIO embedded system and LabVIEW graphical programming tools. The system works as a remote system accessible via the Ethernet. The digital controller operates in real-time conditions, and the maximum sampling frequency is approximately 227 kS s-1. The system was tested with standard sample measurements of α-Fe and α-57Fe2O3 on two different electromechanical velocity transducers. The nonlinearities of the velocity scales in the relative form are better than 0.2%. The replacement of the standard analog PID controller by the new system brings the possibility of optimizing the control process more precisely.

Decentralized digital adaptive control of robot motion

NASA Technical Reports Server (NTRS)

Tarokh, M.

1990-01-01

A decentralized model reference adaptive scheme is developed for digital control of robot manipulators. The adaptation laws are derived using hyperstability theory, which guarantees asymptotic trajectory tracking despite gross robot parameter variations. The control scheme has a decentralized structure in the sense that each local controller receives only its joint angle measurement to produce its joint torque. The independent joint controllers have simple structures and can be programmed using a very simple and computationally fast algorithm. As a result, the scheme is suitable for real-time motion control.