High Data Acquisition Rate Research Articles

The high rate data acquisition system for the SLIM5 beam test

In September 2008 the Slim5 collaboration submitted a low material budget silicon demonstrator to test with protons at the PS beam at CERN. The beam test setup was composed of a four double sided microstrip reference telescope and different detectors (DUTs) placed inside: a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130 nm CMOS Technology and a high resistivity double sided silicon detector, with short strips at 45 ∘ angle to the detectors edge, read out by the FSSR2 chip. All the systems were self-triggered and read out by a fast DAQ system. In the poster the beam test setup as the data acquisition and the trigger system are explained and the data acquisition performances are shown.

Real-time xCELLigence impedance analysis of the cytotoxicity of dental composite components on human gingival fibroblasts

Aim of this study was by continuous monitoring to assay the proliferative capacity of human gingival fibroblasts (HGFs), to investigate cytotoxicity of the most common monomers/comonomers in dental resin composites: bisphenol-A-glycidylmethacrylate (BisGMA), hydroxyethylenemethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), and urethanedimethacrylate (UDMA) in HGFs during 24h exposure using the xCELLigence system. xCELLigence cell index (CI) impedance measurements were performed according to the instructions of the supplier. HGFs were resuspended in medium and subsequently adjusted to 400,000, 200,000, 100,000, and 50,000 cells/mL. After seeding 100 microL of the cell suspensions into the wells of the E-plate 96, HGFs were monitored every 15 min for a period of up to 18 h by the xCELLigence system. Half maximum effect concentrations (EC(50)) were determined based on the dose-response curves derived by xCELLigence measurements. Following real-time analysis, significantly increased EC(50) values of HGFs exposed for 24h to the following substances were obtained: HEMA(a), TEGDMA(b), UDMA(c). The EC(50) values (mean [mmol/L]+/-S.E.M.; n=5) were: HEMA 11.20+/-0.3, TEGDMA(a) 3.61+/-0.2, UDMA(a,b) 0.20+/-0.1, and BisGMA(a,b,c) 0.08+/-0.1. These results are similar to the EC(50) values previously observed with the XTT end-point assay. Our data suggests that the xCELLigence live cell analysis system offers dynamic live cell monitoring and combines high data acquisition rates with ease of handling. Therefore, the xCELLigence system can be used as a rapid monitoring tool for cellular viability and be applied in toxicity testing of xenobiotics using in vitro cell cultures.

Design of a Robust, High-rate Wireless Sensor Network for Static and Dynamic Structural Monitoring

Over recent years, there has been much interest in the use of low-cost wireless transceivers for communication of sensor data to alleviate the expense of widely distributed cable-based sensors in structural monitoring systems. However, while the number of unique wireless sensor platforms has continued to expand rapidly, the lack of success in replicating the number of deployed sensors and sampling rates utilized in previous cable-based systems has led to disillusionment over their use for this application. This article presents a wireless sensing system designed for concurrent measurement of both static and dynamic structural response through strain transducers, accelerometers, and temperature sensors. The network protocol developed supports real-time, high-rate data acquisition from large wireless sensor arrays with essentially no data loss. The current network software enables high-rate acquisition of up to 40 channels across 20 wireless units on a single peer-to-peer network with system expansion enabled through additional networks operating simultaneously on adjacent communication channels. Elements of the system design have been specifically tailored towards addressing condition assessment of highway bridges through strain-based load ratings as well as vibration-based dynamic analysis. However, the flexible system architecture enables the system to serve essentially as an off-the-shelf solution for a wide array of wireless sensing tasks. The wireless sensing units and network performance have been validated through laboratory tests as well as dense large-scale field deployments on an in-service highway bridge.

Photon-counting optical coherence-domain reflectometry using superconducting single-photon detectors

We consider the use of single-photon counting detectors in coherence-domain imaging. Detectors operated in this mode exhibit reduced noise, which leads to increased sensitivity for weak light sources and weakly reflecting samples. In particular, we experimentally demonstrate the possibility of using superconducting single-photon detectors (SSPDs) for optical coherence-domain reflectometry (OCDR). These detectors are sensitive over the full spectral range that is useful for carrying out such imaging in biological samples. With counting rates as high as 100 MHz, SSPDs also offer a high rate of data acquisition if the light flux is sufficient.

Developing a documentation system for desert palaces in Jordan using 3D laser scanning and digital photogrammetry

Desert palaces in Jordan are unique pieces of art scattered in the desert as standing symbols of ancient civilizations. Due to their location, these palaces witness different environmental conditions which affect their status and sustainability. This raises the need to have a 3D documentation system reporting all spatial information for each palace, which can be used later for monitoring purposes. Digital photogrammetry is a generally accepted technique for the collection of 3D representations of the environment. For this reason, this image-based technique has been extensively used to produce high quality 3D models of heritage sites and historical buildings for documentation and presentation purposes. Additionally, terrestrial laser scanners are used, which directly measure 3D surface coordinates based on the run-time of reflected light pulses. These systems feature high data acquisition rates, good accuracy and high spatial data density. Despite the potential of each single approach, in our opinion, maximum benefit is to be expected by a combination of data from both digital cameras and terrestrial laser scanners. By these means the efficiency of data collection as well as the geometric accuracy and visual quality of the collected textured 3D models can be optimized. Within the paper, a 3D documentation system for Umayyad desert palaces in the Jordan desert will be presented using digital photogrammetry and laser scanning. The approach is demonstrated by generating high realistic 3D textured models for Amra and Kharanah palaces.

A data acquisition and control system for high-speed gamma-ray tomography

A data acquisition and control system (DACS) for high-speed gamma-ray tomography based on the USB (Universal Serial Bus) and Ethernet communication protocols has been designed and implemented. The high-speed gamma-ray tomograph comprises five 500 mCi 241Am gamma-ray sources, each at a principal energy of 59.5 keV, which corresponds to five detector modules, each consisting of 17 CdZnTe detectors. The DACS design is based on Microchip's PIC18F4550 and PIC18F4620 microcontrollers, which facilitates an USB 2.0 interface protocol and an Ethernet (IEEE 802.3) interface protocol, respectively. By implementing the USB- and Ethernet-based DACS, a sufficiently high data acquisition rate is obtained and no dedicated hardware installation is required for the data acquisition computer, assuming that it is already equipped with a standard USB and/or Ethernet port. The API (Application Programming Interface) for the DACS is founded on the National Instrument's LabVIEW® graphical development tool, which provides a simple and robust foundation for further application software developments for the tomograph. The data acquisition interval, i.e. the integration time, of the high-speed gamma-ray tomograph is user selectable and is a function of the statistical measurement accuracy required for the specific application. The bandwidth of the DACS is 85 kBytes s−1 for the USB communication protocol and 28 kBytes s−1 for the Ethernet protocol. When using the iterative least square technique reconstruction algorithm with a 1 ms integration time, the USB-based DACS provides an online image update rate of 38 Hz, i.e. 38 frames per second, whereas 31 Hz for the Ethernet-based DACS. The off-line image update rate (storage to disk) for the USB-based DACS is 278 Hz using a 1 ms integration time. Initial characterization of the high-speed gamma-ray tomograph using the DACS on polypropylene phantoms is presented in the paper.

Hardware Implementation of Multiple Fan Beam Projection Technique in Optical Fibre Process Tomography.

The main objective of this project is to implement the multiple fan beam projection technique using optical fibre sensors with the aim to achieve a high data acquisition rate. Multiple fan beam projection technique here is defined as allowing more than one emitter to transmit light at the same time using the switch-mode fan beam method. For the thirty-two pairs of sensors used, the 2-projection technique and 4-projection technique are being investigated. Sixteen sets of projections will complete one frame of light emission for the 2-projection technique while eight sets of projection will complete one frame of light emission for the 4-projection technique. In order to facilitate data acquisition process, PIC microcontroller and the sample and hold circuit are being used. This paper summarizes the hardware configuration and design for this project.

Comprehensive Three-Dimensional Gas Chromatography with Parallel Factor Analysis

Development of a comprehensive, three-dimensional gas chromatograph (GC3) instrument is described. The instrument utilizes two six-port diaphragm valves as the interfaces between three, in-series capillary columns housed in a standard Agilent 6890 gas chromatograph fitted with a high data acquisition rate flame ionization detector. The modulation periods for sampling column one by column two and column two by column three are set so that a minimum of three slices (more commonly four or five) are acquired by the subsequent dimension resulting in both comprehensive and quantitative data. A 26-component test mixture and quantitative standards are analyzed using the GC3 instrument. A useful methodology for three-dimensional (3D) data analysis is evaluated, based on the chemometric technique parallel factor analysis (PARAFAC). Since the GC3 instrument produces trilinear data, we are able to use this powerful chemometric technique, which is better known for the analysis of two-dimensional (2D) separations with multichannel detection (e.g., GC x GC-TOFMS) or multiple samples (or replicates) of 2D data. Using PARAFAC, we mathematically separate (deconvolute) the 3D data "volume" for overlapped analytes (i.e., ellipsoids), provided there is sufficient chromatographic resolution in each of the three separation dimensions. Additionally, PARAFAC is applied to quantify analyte standards. For the quantitative analysis, it is demonstrated that PARAFAC may provide a 10-fold improvement in the signal-to-noise ratio relative to a traditional integration method applied to the raw, baseline-corrected data. The GC3 instrument obtains a 3D peak capacity of 3500 at a chromatographic resolution of one in each separation dimension. Furthermore, PARAFAC deconvolution provides a considerable enhancement in the effective 3D peak capacity.

The effect of sliding velocity on the tribological behavior of copper

The tribological behavior of copper was studied with a pin-on-disk system designed to achieve a wide range of velocities. The system was also designed with a high-rate data acquisition system in order to obtain dynamic friction data. Oxygen free high conductivity (OFHC) copper was used for the disks, and 440C stainless steel balls were used for the pins. The tests were performed under vacuum at varying sliding speeds ranging from 0.05 to 1.5 m/s. The applied load was 1.5 N, and the tests were all run for a total sliding distance of 30 m. Surface changes and surface deformation resulting from sliding were characterized with the use of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). Deformation has been observed on the surfaces of the disks accompanied by material transfer from the disk to the pin. Subsurface deformation was studied using both transmission electron microscope (TEM) and ion channeling contrast imaging with the focused ion beam (FIB). FIB milling was used to prepare site-specific TEM foils from the wear track. Extensive subsurface deformation produced a nanocrystalline region adjacent to the sliding surface and heavily deformed grains further into the specimens. In some cases, recrystallized grains were observed below the nanocrystalline region. Differences in the coefficient of friction were correlated with differences in the pattern of transfer from the disk to the pin.

Tomographic imaging: multiple-fan-beam projection technique using optical fiber sensors

This paper presents the timing advantage of implementing a multiple-fan-beam projection technique using optical fiber sensors for a tomography system. To prepare the sensors to be used for this projection, a collimator is not needed, but optical fiber lens termination is crucial. In this research, the fiber optic lens for transmitters is modeled by experimental methods to transmit light at an emission angle of 30 deg. Due to this small emission angle, a multiprojection technique can be implemented without the light overlapping. A multiple-fan-beam projection technique is here defined as one allowing more than one emitter to project light at the same time using the switch-mode fan-beam method. This method can increase the optical sensor's ability for flow visualization. For the 32 pairs of sensors used, the two-projection technique and four-projection technique were investigated. Sixteen sets of projections formed one frame of light emission for the two-projection technique, and eight sets did so for the four-projection technique. Compared to the conventional single-light projection used in the switch-mode fan-beam method, multiple-light projection can achieve a higher data acquisition rate, thus minimizing data loss and producing a more accurate real-time tomographic image. For four projections the data acquisition rate is 609.76 frames/s.

New Experimental Platform for Studies of Turbulence and Turbulent Mixing in Accelerating and Rotating Fluids at High Reynolds Numbers

We present a new experimental platform for studies of turbulence and turbulent mixing in accelerating and rotating fluids. The technology is based on the ultra-high performance optical holographic digital data storage. The state-of-the-art electro-mechanical, electronic, and laser components allow for realization of turbulent flows with high Reynolds number (>107) in a relatively small form-factor, and quantification of their properties with extremely high spatio-temporal resolutions and high data acquisition rates. The technology can be applied for investigation of a large variety of hydrodynamic problems including the fundamental properties of non-Kolmogorov turbulence and turbulent mixing in accelerating, rotating and multiphase flows, magneto-hydrodynamics, and laboratory astrophysics. Unique experimental and metrological capabilities enable the studies of spatial and temporal properties of the transports of momentum, angular momentum, and energy and the identification of scalings, invariants, and statistical properties of these complex turbulent flows.

Fast RPLC-UV method on short sub-two microns particles packed column for the assay of tenoxicam in plasma samples

An extraction-less sample preparation technique followed by a RPLC-UV method on sub-two microns particles packed short column were used for the assay of tenoxicam in plasma samples. Protein precipitation was made by means of trichloroacetic acid addition. Supernatant was injected to the chromatographic column without any further pH adjustment. The mobile phase consisted in a mixture of acetonitrile and aqueous 0.1% phosphoric acid, at 2 mL/min flow rate and gradient elution. The Zorbax SB-C18 ® column (50 mm length, 4.6 mm internal diameter and 1.8 μm particle size) was thermostated at 60 °C. The mobile phase gradient composition program allowed separation of tenoxicam and piroxicam (internal standard), column clean-up and re-equilibration within 4 min. UV detection was achieved at 368 ± 10 nm. The method is characterized by a low limit of quantitation of 25 ng/mL for tenoxicam, with a linearity interval up to 5500 ng/mL. The use of a low volume detection cell and detector high frequency data acquisition rate produced high precision and accuracy through a whole bioequivalence study of tenoxicam in two commercially available tablet formulations, after a single oral administration dose. Full method validation is presented. The high throughput characteristic of the proposed method allowed full validation and bioanalytical study completion within a 96 h period.

Atom probe tomography characterization of solute segregation to dislocations and interfaces

The level and extent of solute segregation to individual dislocations and interfaces may be visualized and quantified by atom probe tomography. The large volume of analysis and high data acquisition rate of the local electrode atom probe (LEAP®) enables the solute distribution in the region of and along the core of dislocations to be estimated. Solute segregation at precipitate-matrix interfaces of precipitates as small as 2-nm diameter may be quantified. Examples are presented of solute segregation to dislocations and clustering/precipitation in a neutron irradiated Fe–Ni–P model alloy and the neutron irradiated beltline weld from the Midland reactor.

Improved echo volumar imaging (EVI) for functional MRI

Echo volumar imaging (EVI) is a 3D modification of echo-planar imaging (EPI) that allows data from an entire volume to be acquired following a single RF excitation. EVI provides a high rate of volumar data acquisition, which is advantageous for functional MRI (fMRI). However, few studies to date have applied EVI to fMRI, since because of gradient hardware limitations EVI generally has to be used with long sampling times, resulting in high sensitivity to susceptibility-induced distortions. In this study we modified the EVI sequence to improve its suitability for fMRI. The sampling time is reduced by the use of a high gradient-switching frequency, a small number of echoes, and outer volume suppression (OVS); rewind gradients ameliorate Nyquist ghosting; and phase correction via a calibration scan reduces ghosting and distortion. It is shown that the modified EVI sequence allows fMRI data to be acquired with a temporal resolution of 167 ms.

Efficient and highly reproducible capillary electrophoresis–mass spectrometry of peptides using Polybrene‐poly(vinyl sulfonate)‐coated capillaries

The potential of capillaries noncovalently coated with a bilayer of oppositely charged polymers for the analysis of peptides by CE-MS was investigated. Bilayer coatings were produced by subsequently rinsing fused-silica capillaries with a solution of Polybrene (PB) and poly(vinyl sulfonate) (PVS). The PB-PVS coating showed to be fully compatible with MS detection causing no ionization suppression or background signals. The bilayer coating provided a considerable EOF at low pH, thereby facilitating the fast separation of peptides using a BGE of formic acid (pH 2.5). Under optimized CE-MS conditions, for enkephalin peptides high separation efficiencies were obtained with plate numbers in the range of 300,000-500,000. It is demonstrated that both the cancellation of the hydrodynamic capillary flow induced by the nebulizer gas and a sufficiently high-data acquisition rate are crucial for achieving these efficiencies. The overall performance of the CE-MS system using PB-PVS-coated capillaries was evaluated by the analysis of a tryptic digest of cytochrome c. The system provided an efficient separation of the peptide mixture, which could be effectively monitored by MS/MS detection allowing identification of at least 13 peptides within a time interval of 1.5 min. In addition, the PB-PVS coating proved to be very consistent yielding stable CE-MS patterns with highly favorable migration time reproducibilities (RSDs < 1% over a 3-day period).

Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data

Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained from a linear fit to many tens or hundreds of temperature change data points. In contrast, thermal diffusivity calculations require a nonlinear fit to the measured temperature change occurring in the first few tenths of a second of the measurement, resulting in a lower accuracy than that obtained for thermal conductivity. Specific heat is calculated from the ratio of thermal conductivity to diffusivity, and thus can have an uncertainty no better than that of the diffusivity estimate. Our thermal conductivity measurements of ice Ih and of tetrahydrofuran (THF) hydrate, made using a 1.6mm outer diameter needle probe and a data acquisition rate of 18.2points∕s, agree with published results. Our thermal diffusivity and specific heat results reproduce published results within 25% for ice Ih and 3% for THF hydrate.

9.3: The Use of an Imaging Sphere for High-Throughput Measurements of Display Performance — Technical Challenges and Mathematical Solutions

For display metrology, two of the most important parameters are brightness and color as a function of angle. Here we describe a new technique based on an imaging sphere, featuring optomechanical simplicity and high data acquisition rates, compared to traditional techniques. We also show how raw data is converted into parametric information, illustrated with real test data.

Analysis of a micropolarizer array-based simultaneous phase-shifting interferometer

Recent technological innovations have enabled the development of a new class of dynamic (vibration-insensitive) interferometer based on a CCD pixel-level phase-shifting approach. We present theoretical and experimental results for an interferometer based on this pixelated phase-shifting technique. Analyses of component errors and instrument functionality are presented. We show that the majority of error sources cause relatively small magnitude peak-to-valley errors in measurement of the order of 0.002-0.005lambda. These errors are largely mitigated by high-rate data acquisition and consequent data averaging.

Tensile testing of ultrathin polycrystalline films: A synchrotron-based technique

The mechanical properties of metallic thin films on the nanoscale acquire increasingly more importance as applications in microelectromechanical systems/NEMS as well as microelectronics have reached this size scale. Here, we present a synchrotron x-ray diffraction technique by which it is possible to characterize the evolution of mechanical stress in a metallic film thinner than 100 nm at measurement times shorter than 60 s per data point. This high data acquisition rate is achieved because no relative motions or tilting of specimen, x-ray source and detector (a large-area charge coupled device camera) are required. The technique comprises an initial “sin2 ψ” measurement to establish the absolute stress values followed by periodic “sin2 φ” measurements during straining to determine stress increments. We describe an experimental setup established at the synchrotron radiation source ANKA (Karlsruhe, Germany) which is specifically suited for monitoring the stress evolution during in situ tensile tests on thin films deposited on compliant polymeric substrates. First stress-strain curves, measured in this way, for a 40-nm-thick gold film are presented.

Experimental Investigation of the Periodic Unsteady Transonic Flow Field Around a Compressor Blade by Means of Particle Image Velocimetry (PIV)

In the present article, a study of the time‐dependent transonic flow field around an isolated airfoil in a Laval nozzle is presented. In order to obtain instantaneous flow field information all over the flow around the blade, the Particle Image Velocimetry (PIV) method has been employed allowing one to obtain velocity data in an illuminated light sheet with a high data acquisition rate and high spatial resolution. From these instantaneous PIV measurements the mean velocity field and turbulence quantities of the flow easily can be obtained by statistical means.A single compressor blade with a NACA 3506 profile and a chord length of 78 mm is centrally mounted in the test section. A vibration system driven by a hydraulic motor is externally attached to the blade. The rotational motion of the motor is translated to a plunging blade vibration perpendicular to the chord via an eccentric shaft and connecting arm. The vibration frequency can be varied between 0 and 100 Hz, and the average amplitude is approximately 0.4 mm. The entire blade‐motor assembly is mounted to the tunnel sidewall via a circular disc to allow easy adjustment of the inlet flow incidence angle. The exit pressure of the nozzle can be varied by a rotating flat plate (15 mm high, 39 mm wide, and 2 mm thick) that is mounted approximately 5 times the chord length downstream of the blade mid‐chord. The rotational frequency of this assembly can be varied between 0 and 100 Hz, producing upstream‐running waves at the doubled frequency (i.e., 0 to 200 Hz). The above excitation systems can be precisely synchronized and the phase lag between them can be freely varied. This allows for unsteady measurements to be conducted in the presence of only the downstream perturbation, only the blade vibration, or a combination of the two for different phase angles.For the first test series the existing PIV measurement system at Turbomachinery Institute (LTT) has been applied to measure the transonic steady flow field around the compressor blade. In another test series, measurements of the time‐dependent periodic flow field were conducted by means of PIV. This measurement series consisted of three subtasks: the measurement of the unsteady flow field with only back pressure variation, with only blade vibration, and finally with a combination of both back pressure variation and blade vibration. These results quantify not only the unsteady motion of the normal shock for each case on the suction side of the blade, but also give a detailed insight into the instantaneous transonic flow field around the compressor blade. Furthermore, the results of the set of unsteady measurements with both back pressure variation and blade vibration (3) is compared with the combination of the results of the sets of unsteady measurements of only back pressure variation (1) and only blade vibration (2) to validate the superposition principle.Finally, phase averaging of the instantaneous flowquantities produced a large database for statistical treatment (e.g., turbulence) and thus the ability to compare the averaged results with those from traditional measurement techniques.