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Sample records for acousto-ultrasonic scan system

  1. High-Performance Scanning Acousto-Ultrasonic System

    NASA Technical Reports Server (NTRS)

    Roth, Don; Martin, Richard; Kautz, Harold; Cosgriff, Laura; Gyekenyesi, Andrew

    2006-01-01

    A high-performance scanning acousto-ultrasonic system, now undergoing development, is designed to afford enhanced capabilities for imaging microstructural features, including flaws, inside plate specimens of materials. The system is expected to be especially helpful in analyzing defects that contribute to failures in polymer- and ceramic-matrix composite materials, which are difficult to characterize by conventional scanning ultrasonic techniques and other conventional nondestructive testing techniques. Selected aspects of the acousto-ultrasonic method have been described in several NASA Tech Briefs articles in recent years. Summarizing briefly: The acousto-ultrasonic method involves the use of an apparatus like the one depicted in the figure (or an apparatus of similar functionality). Pulses are excited at one location on a surface of a plate specimen by use of a broadband transmitting ultrasonic transducer. The stress waves associated with these pulses propagate along the specimen to a receiving transducer at a different location on the same surface. Along the way, the stress waves interact with the microstructure and flaws present between the transducers. The received signal is analyzed to evaluate the microstructure and flaws. The specific variant of the acousto-ultrasonic method implemented in the present developmental system goes beyond the basic principle described above to include the following major additional features: Computer-controlled motorized translation stages are used to automatically position the transducers at specified locations. Scanning is performed in the sense that the measurement, data-acquisition, and data-analysis processes are repeated at different specified transducer locations in an array that spans the specimen surface (or a specified portion of the surface). A pneumatic actuator with a load cell is used to apply a controlled contact force. In analyzing the measurement data for each pair of transducer locations in the scan, the total

  2. Development of a High Performance Acousto-ultrasonic Scan System

    NASA Technical Reports Server (NTRS)

    Roth, D. J.; Martin, R. E.; Harmon, L. M.; Gyekenyesi, A. L.; Kautz, H. E.

    2002-01-01

    Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition/distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods such as ultrasonic c-scan, x-ray radiography, and thermographic inspection that tend to be used primarily for discrete flaw detection. Through its history, AU has been used to inspect polymer matrix composite, metal matrix composite, ceramic matrix composite, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. In this paper, a review of essential AU technology is given. Additionally, the basic hardware and software configuration, and preliminary results with the system, are described.

  3. Development of a High Performance Acousto-Ultrasonic Scan System

    NASA Astrophysics Data System (ADS)

    Roth, D. J.; Martin, R. E.; Harmon, L. M.; Gyekenyesi, A. L.; Kautz, H. E.

    2003-03-01

    Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition/distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods such as ultrasonic c-scan, x-ray radiography, and themographic inspection that tend to be used primarily for discrete flaw detection. Through its history, AU has been used to inspect polymer matrix composite, metal matrix composite, ceramic matrix composite, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. In this paper, a review of essential AU technology is given. Additionally, the basic hardware and software configuration, and preliminary results with the system, are described.

  4. Development of a High Performance Acousto-Ultrasonic Scan System

    NASA Astrophysics Data System (ADS)

    Roth, D. J.; Martin, R. E.; Harmon, L. M.; Gyekenyesi, A. L.; Kautz, H. E.

    2002-10-01

    Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition/distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods such as ultrasonic c-scan, x-ray radiography, and thermographic inspection that tend to be used primarily for discrete flaw detection. Through its history, AU has been used to inspect polymer matrix composite, metal matrix composite, ceramic matrix composite, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. In this paper, a review of essential AU technology is given. Additionally, the basic hardware and software configuration, and preliminary results with the system, are described.

  5. Acousto-ultrasonic system for the inspection of composite armored vehicles

    NASA Astrophysics Data System (ADS)

    Godinez, Valery F.; Carlos, Mark F.; Delamere, Michael; Hoch, William; Fotopoulos, Christos; Dai, Weiming; Raju, Basavaraju B.

    2001-04-01

    In this paper the design and implementation of a unique acousto-ultrasonics system for the inspection of composite armored vehicles is discussed. The system includes a multi-sensor probe with a position-tracking device mounted on a computer controlled scanning bridge. The system also includes an arbitrary waveform generator with a multiplexer and a multi-channel acoustic emission board capable of simultaneously collecting and processing up to four acoustic signals in real time. C-scans of an armored vehicle panel with defects are presented.

  6. Acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1990-01-01

    The theoretical development, methodology, and potential applications of acousto-ultrasonic nondestructive testing are set forth in an overview to assess the effectiveness of the technique. Stochastic wave propagation is utilized to isolate and describe defects in fiber-reinforced composites, particularly emphasizing the integrated effects of diffuse populations of subcritical flaws. The generation and nature of acousto-ultrasonic signals are described in detail, and stress-wave factor analysis of the signals is discussed. Applications of acousto-ultrasonics are listed including the prediction of failure sites, assessing fatique and impact damage, calculating ultimate tensile strength, and determining interlaminar bond strength. The method can identify subtle but important variations in fiber-reinforced composites, and development of the related instrumentation technology is emphasized.

  7. Acousto-ultrasonics - An update

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1989-01-01

    The application possibilities and limitations of acoustoultrasonics are reviewed. One of the most useful aspects of acousto-ultrasonics is its ability to assess degradation and damage states in composites. The sensitivity of the acousto-ultrasonic approach for detecting and measuring subtle but significant material property variations in composites has been demonstrated.

  8. Investigation of an expert health monitoring system for aeronautical structures based on pattern recognition and acousto-ultrasonics

    NASA Astrophysics Data System (ADS)

    Tibaduiza-Burgos, Diego Alexander; Torres-Arredondo, Miguel Angel

    2015-08-01

    Aeronautical structures are subjected to damage during their service raising the necessity for periodic inspection and maintenance of their components so that structural integrity and safe operation can be guaranteed. Cost reduction related to minimizing the out-of-service time of the aircraft, together with the advantages offered by real-time and safe-life service monitoring, have led to a boom in the design of inexpensive and structurally integrated transducer networks comprising actuators, sensors, signal processing units and controllers. These kinds of automated systems are normally referred to as smart structures and offer a multitude of new solutions to engineering problems and multi-functional capabilities. It is thus expected that structural health monitoring (SHM) systems will become one of the leading technologies for assessing and assuring the structural integrity of future aircraft. This study is devoted to the development and experimental investigation of an SHM methodology for the detection of damage in real scale complex aeronautical structures. The work focuses on each aspect of the SHM system and highlights the potentialities of the health monitoring technique based on acousto-ultrasonics and data-driven modelling within the concepts of sensor data fusion, feature extraction and pattern recognition. The methodology is experimentally demonstrated on an aircraft skin panel and fuselage panel for which several damage scenarios are analysed. The detection performance in both structures is quantified and presented.

  9. The acousto-ultrasonic approach

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1987-01-01

    The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

  10. The acousto-ultrasonic approach. [for NDE

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1988-01-01

    The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

  11. Nondestructive evaluation by acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    Acousto-ultrasonics is an ultrasonic technique that was originally devised to cope with the particular problems associated with nondestructive evaluation (NDE) of fiber/polymer composite structures. The fiber/polymer composites are more attenuating to ultrasound than any other material presently of interest. This limits the applicability of high-frequency ultrasonics. A common use of ultrasound is the imaging of flaws internal to a structure by scattering from the interface with the flaw. However, structural features of composites can scatter ultrasound internally, thus obscuring the flaws. A need relative to composites is to be able to nondestructively measure the strength of laminar boundaries in order to assess the integrity of a structure. Acousto-ultrasonics has exhibited the ability to use the internal scattering to provide information for determining the strength of laminar boundaries. Analysis of acousto-ultrasonic signals by the wave ray paths that compose it leads to waveform partitioning that enhances the sensitivity to mechanical strength parameters.

  12. Review of acousto-ultrasonic NDE for composites

    NASA Technical Reports Server (NTRS)

    Vary, Alex; Kautz, Harold

    1990-01-01

    Acousto-ultrasonics utilizes simulated stress waves to detect and quantify defect states, damage conditions, and variations of mechanical properties in fiber reinforced composites. The term acousto-ultrasonics denotes a combination of aspects of acoustic emission methodology with ultrasonic materials characterization. The acousto-ultrasonic approach was developed to deal primarily with evaluation of the integrated effect of minor flaws and diffuse flaw populations of subcritical flaws in composite and bonded structures. These factors singly and collectively also influence acousto-ultrasonic measurements that, in turn, correlate with dynamic response and mechanical property variations. Since it was first introduced, the acousto-ultrasonic approach was successfully applied to a variety of materials, including polymeric, metallic, and ceramic matrix composites; adhesively bonded materials; paper and wood products; cable and rope; and also human bone. Examples of applications and limitations of the approach are reviewed. Basic methods and guidelines are discussed. The underlying hypothesis and theory development needs are indicated.

  13. Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection

    NASA Technical Reports Server (NTRS)

    Huber, Robert D.; Green, Robert E., Jr.; Vary, Alex; Kautz, Harold

    1990-01-01

    Presented in viewgraph format, the possibility of using laser generation and detection of ultrasound to replace piezoelectric transducers for the acousto-ultrasonic technique is advanced. The advantages and disadvantages of laser acousto-ultrasonics are outlined. Laser acousto-ultrasonics complements standard piezoelectric acousto-ultrasonics and offers non-contact nondestructive evaluation.

  14. Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Huber, Robert D.; Green, Robert E., Jr.

    1990-01-01

    The acousto-ultrasonic method has proven to be a most interesting technique for nondestructive evaluation of the mechanical properties of a variety of materials. Use of the technique or a modification thereof, has led to correlation of the associated stress wave factor with mechanical properties of both metals and composite materials. The method is applied to the nondestructive evaluation of selected fiber reinforced structural composites. For the first time, conventional piezoelectric transducers were replaced with laser beam ultrasonic generators and detectors. This modification permitted true non-contact acousto-ultrasonic measurements to be made, which yielded new information about the basic mechanisms involved as well as proved the feasibility of making such non-contact measurements on terrestrial and space structures and heat engine components. A state-of-the-art laser based acousto-ultrasonic system, incorporating a compact pulsed laser and a fiber-optic heterodyne interferometer, was delivered to the NASA Lewis Research Center.

  15. Acousto-ultrasonics - Retrospective exhortation with bibliography

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1991-01-01

    Major research on the acousto-ultrasonic (AU) technique (also known as the stress-wave-factor technique) encompassing aspects of acoustic emission and ultrasonic materials characterization methodology is reviewed. AU deals primarily with such factors as the assessment of the integrated effects of diffuse defect states, thermomechanical degradation, and population of subcritical flaws that influence AU measurements correlating with mechanical property variations. AU is used to evaluate fiber-reinforced composites, adhesive bonds, lumber, paper and wood products, cable and rope, and human bone. The AU technique has been demonstrated to be sensitive to interlaminar and adhesive bond strength variations and has been shown to be useful in assessing microporosity and microcracking produced by fatigue cycling. An extensive bibliography ranging from 1985 to 1991 is presented.

  16. Noncontact Acousto-Ultrasonics for Material Characterization

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1998-01-01

    A NdYAG 1064 nm, laser pulse was employed to produce ultrasonic waves in specimens of SiC/SiC and SiC/Ti 6-4 composites which are high temperature materials of interest for aerospace applications. Air coupled transducers were used to detect and collect the signals used for acousto-ultrasonic analysis. Conditions for detecting ultrasonic decay signals were examined. The results were compared to those determined on the same specimens with contact coupling. Some non-contact measurements were made employing conventional air focused detectors. Others were performed with a more novel micromachined capacitance transducer. Concerns of the laser-in technology include potential destructiveness of the laser pulse. Repeated laser pulsing at the same location does lead to deterioration of the ultrasonic signal in some materials, but seems to recover with time. Also, unlike contact AU, the frequency regime employed is a function of laser-material interaction rather than the choice of transducers. Concerns of the air coupled-out technology include the effect of air attenuation. This imposes a practical upper limit to frequency of detection. In the case of the experimental specimens studied ultrasonic decay signals could be imaged satisfactorily.

  17. Advanced instrumentation for acousto-ultrasonic based structural health monitoring

    NASA Astrophysics Data System (ADS)

    Smithard, Joel; Galea, Steve; van der Velden, Stephen; Powlesland, Ian; Jung, George; Rajic, Nik

    2016-04-01

    Structural health monitoring (SHM) systems using structurally-integrated sensors potentially allow the ability to inspect for damage in aircraft structures on-demand and could provide a basis for the development of condition-based maintenance approaches for airframes. These systems potentially offer both substantial cost savings and performance improvements over conventional nondestructive inspection (NDI). Acousto-ultrasonics (AU), using structurallyintegrated piezoelectric transducers, offers a promising basis for broad-field damage detection in aircraft structures. For these systems to be successfully applied in the field the hardware for AU excitation and interrogation needs to be easy to use, compact, portable, light and, electrically and mechanically robust. Highly flexible and inexpensive instrumentation for basic background laboratory investigations is also required to allow researchers to tackle the numerous scientific and engineering issues associated with AU based SHM. The Australian Defence Science and Technology Group (DST Group) has developed the Acousto Ultrasonic Structural health monitoring Array Module (AUSAM+), a compact device for AU excitation and interrogation. The module, which has the footprint of a typical current generation smart phone, provides autonomous control of four send and receive piezoelectric elements, which can operate in pitch-catch or pulse-echo modes and can undertake electro-mechanical impedance measurements for transducer and structural diagnostics. Modules are designed to operate synchronously with other units, via an optical link, to accommodate larger transducer arrays. The module also caters for fibre optic sensing of acoustic waves with four intensity-based optical inputs. Temperature and electrical resistance strain gauge inputs as well as external triggering functionality are also provided. The development of a Matlab hardware object allows users to easily access the full hardware functionality of the device and

  18. Quality Evaluation By Acousto-Ultrasonic Testing Of Composites

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1989-01-01

    Promising nondestructive-testing method based on ultrasonic simulation of stress waves. Report reviews acousto-ultrasonic technology for nondestructive testing. Discusses principles, suggests advanced signal-analysis schemes for development, and presents potential applications. Acousto-ultrasonics applied principally to assess defects in laminated and filament-wound fiber-reinforced composite materials. Technique used to determine variations in such properties as tensile, shear, and flexural strengths and reductions in strength and toughness caused by defects. Also used to evaluate states of cure, porosities, orientation of fibers, volume fractions of fibers, bonding between fibers and matrices, and qualities of interlaminar bonds.

  19. Noncontact Acousto-Ultrasonic Testing With Laser Beams

    NASA Technical Reports Server (NTRS)

    Huber, Robert D.; Green, Robert E., Jr.

    1994-01-01

    Laser beams used to excite and detect acoustic waves in specimens. Laser/acousto-ultrasonic technique entails no mechanical contact between specimens and testing apparatus. Apparatus located at relatively large distances (meters) from specimens, making it possible to test specimens too hot for contact measurements or located in inaccessible places, vacuums, or hostile environments.

  20. Nondestructive evaluation/characterization of composite materials and structures using the acousto-ultrasonic techniques

    NASA Technical Reports Server (NTRS)

    Dos Reis, H. L. M.; Vary, A.

    1988-01-01

    This paper introduces the nature and the underlying rational of the acousto-ultrasonic stress wave factor technique and some of its applications to composite materials and structures. Furthermore, two examples of successful application of the acousto-ultrasonic technique are presented in detail. In the first example, the acousto-ultrasonic technique is used to evaluate the adhesive bond strength between rubber layers and steel plates, and in the seocnd example the tehcnique is used to monitor progressive damage in wire rope.

  1. Acousto-ultrasonic evaluation of ceramic matrix composite materials

    NASA Technical Reports Server (NTRS)

    Dosreis, Henrique L. M.

    1991-01-01

    Acousto-ultrasonic nondestructive evaluation of ceramic composite specimens with a lithium-alumino-silicate glass matrix reinforced with unidirectional silicon carbide (NICALON) fibers was conducted to evaluate their reserve of strength. Ceramic composite specimens with different amount of damage were prepared by four-point cyclic fatigue loading of the specimens at 500 C for a different number of cycles. The reserve of strength of the specimens was measured as the maximum bending stress recorded during four-pointed bending test with the load monotonically increased until failure occurs. It was observed that the reserve of strength did not correlate with the number of fatigue cycles. However, it was also observed that higher values of the stress wave factor measurements correspond to higher values of the reserve of strength test data. Therefore, these results show that the acousto-ultrasonic approach has the potential of being used to monitor damage and to estimate the reserve of strength of ceramic composites.

  2. Highly reproducible Bragg grating acousto-ultrasonic contact transducers

    NASA Astrophysics Data System (ADS)

    Saxena, Indu Fiesler; Guzman, Narciso; Lieberman, Robert A.

    2014-09-01

    Fiber optic acousto-ultrasonic transducers offer numerous applications as embedded sensors for impact and damage detection in industrial and aerospace applications as well as non-destructive evaluation. Superficial contact transducers with a sheet of fiber optic Bragg gratings has been demonstrated for guided wave ultrasound based measurements. It is reported here that this method of measurement provides highly reproducible guided ultrasound data of the test composite component, despite the optical fiber transducers not being permanently embedded in it.

  3. Transply crack density detection by acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Hemann, John H.; Bowles, Kenneth J.; Kautz, Harold; Cavano, Paul

    1987-01-01

    The acousto-ultrasonic method was applied to a PMR-15 8-harness, satin Celion 3000 fabric composite to determine the extent of transply cracking. A six-ply 0/90 laminate was also subjected to mechanical loading, which induced transply cracking. The stress wave factor (SWF) is defined as the energy contained in the received signal from a 2.25-MHz center frequency transducer. The correlation of the SWF with transply crack density is shown.

  4. Piezoelectric phased array acousto-ultrasonic interrogation of damage in thin plates

    NASA Astrophysics Data System (ADS)

    Purekar, Ashish S.

    Structural Health Monitoring (SHM) and Condition Based Maintenance (CBM) systems can provide substantial benefits for aging aerospace systems as well as newer systems still in the design process. In aging aerospace systems, a retrofitted SHM system would alert users of incipient damage preventing catastrophic failure. For newer systems, incorporating a SHM approach and using CBM techniques can reduce life-cycle costs. Central to such SHM and CBM systems is the ability to detect damage in a structure. Traditional approaches to damage detection in structures involve one of two methods. In the modal dynamics approach, the natural frequencies and modeshapes of a structure shift when damage occurs. The location, type, and amount of damage is determined by the shifts in the modal properties due to damage. Alternately, in an Ultrasonics approach, the structure is scanned with a specialized transducer which induces high frequency vibrations in the structure. Damage in the structure is inferred when these vibrations are altered. In the same vein as Ultrasonics, Acoustic Emission based methods listen for energy release in the structure upon defect growth. All of these techniques have limitations which hinder their usage in a practical system. This thesis attempts to develop a methodology with the benefits of the modal approach as well as the Ultrasonics/Acoustic Emission approach. The methodology is commonly referred to as an Acousto-Ultrasonic technique for damage detection. The structural dynamics of plate structures is described as wavelike in nature where the plate is a medium for wave propagation. For thin plates, bulk wave propagation is described using Lamb wave modes. The two fundamental modes of wave propagation are the in-plane acoustic mode and the transverse bending mode. The interaction of these waves with a discontinuity or damaged region changes the way the waves propagate. Part of the incident wavefront is reflected back while the rest is transmitted through

  5. Noncontact acousto-ultrasonics using laser generation and laser interferometric detection

    NASA Technical Reports Server (NTRS)

    Green, Robert E., Jr.; Huber, Robert D.

    1991-01-01

    A compact, portable fiber-optic heterodyne interferometer designed to detect out-of-plane motion on surfaces is described. The interferometer provides a linear output for displacements over a broad frequency range and can be used for ultrasonic, acoustic emission, and acousto-ultrasonic (AU) testing. The interferometer in conjunction with a compact pulsed Nd:YAG laser represents a noncontact testing system. This system was tested to determine its usefulness for the AU technique. The results obtained show that replacement of conventional piezoelectric transducers (PZT) with a laser generation/detection system make it possible to carry out noncontact AU measurements. The waveforms recorded were 5 MHZ PZT-generated ultrasound propagating through an aluminum block, detection of the acoustic emission event, and laser AU waveforms from graphite-epoxy laminates and a filament-wound composite.

  6. Acousto-ultrasonic measurements to monitor damage during fatigue of composites

    NASA Technical Reports Server (NTRS)

    Govada, A.; Henneke, E. G.; Talreja, R.

    1984-01-01

    An acousto-ultrasonic nondestructive testing method used to monitor damage during static and fatigue loading of thin graphite epoxy laminates is described. The experimental procedure, the signal analysis by the Fast Fourier Transform (FFT) algorithm, and the results of this analysis are discussed. Quasi-static tension tests showed a sharp decrease in the quantitative parameters when transverse cracks developed in the 90 degrees plies of a (0, 90/2/)s laminate. When internal micro-delaminations unite to form macro-delaminations, a sharp decrease in the parameters is also observed. The parameters are found to correlate well with other indications of damage development such as stiffness and degradation. The root mean square value of the moment is found to be more sensitive to damage than stiffness. Various signals and spectrums of graphite epoxy systems are presented.

  7. Acousto-ultrasonics as a monitor of material anisotropy

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Kiernan, M. T.

    1988-01-01

    This paper discusses experimental results obtained by performing the acousto-ultrasonic (AU) method at various azimuthal angles on the surface of fiber-reinforced composite plates. The use of an IBM-PC/data-acquisition board to obtain a digitized AU signal to be analyzed by specially developed software is described. An introduction is given to the use of AU parameters to quantify information evidenced in amplitude/frequency plots. A description of how the parameters are obtained by calculating various spectral moments and the area under particular ranges of the spectral density curve is presented. Results are given from voltage/time plots, amplitude/frequency plots, and plots showing the variation of calculated AU parameters with azimuthal angle. Finally, how the variation of AU parameters with azimuthal angle may be related to variation in material properties with azimuthal angle is discussed.

  8. Acousto-ultrasonics to Assess Material and Structural Properties

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    2002-01-01

    This report was created to serve as a manual for applying the Acousto-Ultrasonic NDE method, as practiced at NASA Glenn, to the study of materials and structures for a wide range of applications. Three state of the art acousto-ultrasonic (A-U) analysis parameters, ultrasonic decay (UD) rate, mean time (or skewing factor, "s"), and the centroid of the power spectrum, "f(sub c)," have been studied and applied at GRC for NDE interrogation of various materials and structures of aerospace interest. In addition to this, a unique application of Lamb wave analysis is shown. An appendix gives a brief overview of Lamb Wave analysis. This paper presents the analysis employed to calculate these parameters and the development and reasoning behind their use. It also discusses the planning of A-U measurements for materials and structures to be studied. Types of transducer coupling are discussed including contact and non-contact via laser and air. Experimental planning includes matching transducer frequency range to material and geometry of the specimen to be studied. The effect on results of initially zeroing the DC component of the ultrasonic waveform is compared with not doing so. A wide range of interrogation problems are addressed via the application of these analysis parameters to real specimens is shown for five cases: Case 1: Differences in density in [0] SiC/RBSN ceramic matrix composite. Case 2: Effect of tensile fatigue cycling in [+/-45] SiC/SiC ceramic matrix composite. Case 3: Detecting creep life, and failure, in Udimet 520 Nickel-Based Super Alloy. Case 4: Detecting Surface Layer Formation in T-650-35/PMR-15 Polymer Matrix Composites Panels due to Thermal Aging. Case 5: Detecting Spin Test Degradation in PMC Flywheels. Among these cases a wide range of materials and geometries are studied.

  9. Multivariate data-driven modelling and pattern recognition for damage detection and identification for acoustic emission and acousto-ultrasonics

    NASA Astrophysics Data System (ADS)

    Torres-Arredondo, M.-A.; Tibaduiza, D.-A.; McGugan, M.; Toftegaard, H.; Borum, K.-K.; Mujica, L. E.; Rodellar, J.; Fritzen, C.-P.

    2013-10-01

    Different methods are commonly used for non-destructive testing in structures; among others, acoustic emission and ultrasonic inspections are widely used to assess structures. The research presented in this paper is motivated by the need to improve the inspection capabilities and reliability of structural health monitoring (SHM) systems based on ultrasonic guided waves with focus on the acoustic emission and acousto-ultrasonics techniques. The use of a guided wave based approach is driven by the fact that these waves are able to propagate over relatively long distances, and interact sensitively and uniquely with different types of defect. Special attention is paid here to the development of efficient SHM methodologies. This requires robust signal processing techniques for the correct interpretation of the complex ultrasonic waves. Therefore, a variety of existing algorithms for signal processing and pattern recognition are evaluated and integrated into the different proposed methodologies. As a contribution to solve the problem, this paper presents results in damage detection and classification using a methodology based on hierarchical nonlinear principal component analysis, square prediction measurements and self-organizing maps, which are applied to data from acoustic emission tests and acousto-ultrasonic inspections. At the end, the efficiency of these methodologies is experimentally evaluated in diverse anisotropic composite structures.

  10. Experimental Investigation on Acousto-Ultrasonic Sensing Using Polarization-Maintaining Fiber Bragg Gratings

    NASA Technical Reports Server (NTRS)

    Wang, Gang; Banks, Curtis E.

    2015-01-01

    This report discusses the guided Lamb wave sensing using polarization-maintaining (PM) fiber Bragg grating (PM-FBG) sensor. The goal is to apply the PM-FBG sensor system to composite structural health monitoring (SHM) applications in order to realize directivity and multi-axis strain sensing capabilities while using reduced number of sensors. Comprehensive experiments were conducted to evaluate the performance of the PM-FBG sensor in a composite panel structure under different actuation frequencies and locations. Three Macro-Fiber-Composite (MFC) piezoelectric actuators were used to generate guided Lamb waves and they are oriented at 0, 45, and 90 degrees with respect to PM-FBG axial direction, respectively. The actuation frequency was varied from 20kHz to 200kHz. It is shown that the PM-FBG sensor system is able to detect high-speed ultrasound waves and capture the characteristics under different actuation conditions. Both longitudinal and lateral strain components in the order of nano-strain were determined based on the reflective intensity measurement data from fast and slow axis of the PM fiber. It must be emphasized that this is the first attempt to investigate acousto-ultrasonic sensing using PM-FBG sensor. This could lead to a new sensing approach in the SHM applications.

  11. Damage Assessment of Creep Tested and Thermally Aged Udimet 520 Using Acousto-Ultrasonics

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, Andrew L.; Kautz, Harold E.; Cao, Wei

    2001-01-01

    Due to elevated temperatures and excessive stresses, turbine components may experience creep behavior. As a result, it is desirable to monitor and assess the current condition of such components. This study employed the Acousto-Ultrasonics (AU) method in an effort to monitor the state of the material at various percentages of used up creep life in the nickel base alloy, Udimet 520. A stepped specimen (i.e., varying cross sectional area) was employed which allowed for a postmortem nondestructive evaluation (NDE) analysis of the various levels of used up life. The overall objectives here were two fold: First, a user friendly, graphical interface AU system was developed, and second the new AU system was applied as an NDE tool to assess distributed damage resulting from creep. The experimental results demonstrated that the AU method shows promise as an NDE tool capable of detecting material changes as a function of used up creep life. Furthermore, the changes in the AU parameters were mainly attributed to the case of combined load and elevated temperature (i.e., creep) and not simply because of a timed exposure at elevated temperature (i.e., heat treatment or thermal aging).

  12. Acousto-ultrasonics-based fatigue damage characterization: Linear versus nonlinear signal features

    NASA Astrophysics Data System (ADS)

    Su, Zhongqing; Zhou, Chao; Hong, Ming; Cheng, Li; Wang, Qiang; Qing, Xinlin

    2014-03-01

    Engineering structures are prone to fatigue damage over service lifespan, entailing early detection and continuous monitoring of the fatigue damage from its initiation through growth. A hybrid approach for characterizing fatigue damage was developed, using two genres of damage indices constructed based on the linear and the nonlinear features of acousto-ultrasonic waves. The feasibility, precision and practicability of using linear and nonlinear signal features, for quantitatively evaluating multiple barely visible fatigue cracks in a metallic structure, was compared. Miniaturized piezoelectric elements were networked to actively generate and acquire acousto-ultrasonic waves. The active sensing, in conjunction with a diagnostic imaging algorithm, enabled quantitative evaluation of fatigue damage and facilitated embeddable health monitoring. Results unveiled that the nonlinear features of acousto-ultrasonic waves outperform their linear counterparts in terms of the detectability. Despite the deficiency in perceiving small-scale damage and the possibility of conveying false alarms, linear features show advantages in noise tolerance and therefore superior practicability. The comparison has consequently motivated an amalgamation of linear and nonlinear features of acousto-ultrasonic waves, targeting the prediction of multi-scale damage ranging from microscopic fatigue cracks to macroscopic gross damage.

  13. A preliminary investigation of acousto-ultrasonic NDE of metal matrix composite test specimens

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.; Lerch, Brad A.

    1991-01-01

    Acousto-ultrasonic (AU) measurements were performed on a series of tensile specimens composed of 8 laminated layers of continuous, SiC fiber reinforced Ti-15-3 matrix. The following subject areas are covered: AU signal analysis; tensile behavior; AU and interrupted tensile tests; AU and thermally cycled specimens; AU and stiffness; and AU and specimen geometry.

  14. An acousto-ultrasonics pattern recognition approach for the characterization of the mechanical response of engineering materials

    SciTech Connect

    Haddad, Y.M.; Molina, G.

    1996-10-01

    Acousto-Ultrasonic technique, in conjunction with pattern recognition methodology, is demonstrated to be a successful non-destructive tool for the characterization of the mechanical response of engineering materials. In this context, the value of the internal stress, under different mechanical inputs, is correlated with the so-called Acousto-ultrasonic Parameter (AUP). The latter is an identification property of the wave propagation characteristics of the material. In this paper, the principles and instrumentations involved in the acousto-ultrasonic technique are described. Statistical pattern recognition methodology, used for the analysis of acousto-ultrasonic waveforms and in the design of the required discriminating classifiers, is presented. Illustrative examples are given concerning the evaluation of the level of stress in a class of engineering materials; namely, Polyvinyl chloride (PVC), due to controlled low-energy impact loading. The presented approach is seen to be useful in estimating the stress-state in on-site members of engineering structures.

  15. An Acoustic Emission and Acousto-Ultrasonic Analysis of Impact Damaged Composite Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.; Workman, Gary L.

    1996-01-01

    The research presented herein summarizes the development of acoustic emission (AE) and acousto-ultrasonic (AU) techniques for the nondestructive evaluation of filament wound composite pressure vessels. Vessels fabricated from both graphite and kevlar fibers with an epoxy matrix were examined prior to hydroburst using AU and during hydroburst using AE. A dead weight drop apparatus featuring both blunt and sharp impactor tips was utilized to produce a single known energy 'damage' level in each of the vessels so that the degree to which the effects of impact damage could be measured. The damage levels ranged from barely visible to obvious fiber breakage and delamination. Independent neural network burst pressure prediction models were developed from a sample of each fiber/resin material system. Here, the cumulative AE amplitude distribution data collected from low level proof test (25% of the expected burst for undamaged vessels) were used to measure the effects of the impact on the residual burst pressure of the vessels. The results of the AE/neural network model for the inert propellant filled graphite/epoxy vessels 'IM7/3501-6, IM7/977-2 and IM7/8553-45' demonstrated that burst pressures can be predicted from low level AE proof test data, yielding an average error of 5.0%. The trained network for the IM7/977-2 class vessels was also able to predict the expected burst pressure of taller vessels (three times longer hoop region length) constructed of the same material and using the same manufacturing technique, with an average error of 4.9%. To a lesser extent, the burst pressure prediction models could also measure the effects of impact damage to the kevlar/epoxy 'Kevlar 49/ DPL862' vessels. Here though, due to the higher attenuation of the material, an insufficient amount of AE amplitude information was collected to generate robust network models. Although, the worst case trial errors were less than 6%, when additional blind predictions were attempted, errors as

  16. Damage Assessment of Creep Tested and Thermally Aged Metallic Alloys Using Acousto-Ultrasonics

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, Andrew L.; Kautz, Harold E.; Baaklini, George Y.

    2001-01-01

    In recent years emphasis has been placed on the early detection of material changes experienced in turbine powerplant components. During the scheduled overhaul of a turbine, the current techniques of examination of various hot section components aim to find flaws such as cracks, wear, and erosion, as well as excessive deformations. Thus far, these localized damage modes have been detected with satisfactory results. However, the techniques used to find these flaws provide no information on life until the flaws are actually detected. Major improvements in damage assessment, safety, as well as more accurate life prediction could be achieved if nondestructive evaluation (NDE) techniques could be utilized to sense material changes that occur prior to the localized defects mentioned. Because of elevated temperatures and excessive stresses, turbine components may experience creep behavior. As a result, it is desirable to monitor and access the current condition of such components. Research at the NASA Glenn Research Center involves developing and utilizing an NDE technique that discloses distributed material changes that occur prior to the localized damage detected by the current methods of inspection. In a recent study, creep processes in a nickel-base alloy were the life-limiting condition of interest, and the NDE technique was acousto-ultrasonics (AU). AU is an NDE technique that utilizes two ultrasonic transducers to interrogate the condition of a test specimen. The sending transducer introduces an ultrasonic pulse at a point on the surface of the specimen while a receiving transducer detects the signal after it has passed through the material. The goal of the method is to correlate certain parameters of the detected waveform to characteristics of the material between the two transducers. Here, the waveform parameter of interest is the attenuation due to internal damping for which information is being garnered from the frequency domain. The parameters utilized to

  17. Nondestructive Evaluation of Adhesively Bonded Joints by Acousto-Ultrasonic Technique and Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Nayeb-Hashemi, Hamid; Rossettos, J. N.

    1997-01-01

    Reliable applications of adhesively bonded joints require an effective nondestructive evaluation technique for their bond strength prediction. To properly evaluate factors affecting bond strength, effects of defects such as voids and disbonds on stress distribution in the overlap region must be understood. At the same time, in order to use acousto-ultrasonic (AU) technique to evaluate bond quality, the effect of these defects on dynamic response of single lap joints must be clear. The stress distribution in a single lap joint with and without defects (void or disbond) is analyzed. A bar-Theta parameter which contains adherend and adhesive thickness and properties is introduced. It is shown for bonded joints with bar-Theta greater than 10, that a symmetric void or disbond in the middle of overlap up to the 70 percent of overlap length has negligible effect on bond strength. In contrast frequency response analyses by a finite element technique showed that the dynamic response is affected significantly by the presence of voids or disbonds. These results have direct implication in the interpretations of AU results. Through transmission attenuation and a number of AU parameters for various specimens with and without defects are evaluated. It is found that although void and disbond have similar effects on bond strength (stress distribution), they have completely different effects on wave propagation characteristics. For steel-adhesive-steel specimens with voids, the attenuation changes are related to the bond strength. However, the attenuation changes for specimens with disbond are fairly constant over a disbond range. In order to incorporate the location of defects in AU parameters, a weighting function is introduced. Using an immersion system with focused transducers, a number of AU parameters are evaluated. It is found that by incorporating weighting functions in these parameters better sensitivities (AU parameters vs. bond strength) are achieved. Acoustic emission

  18. Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  19. Detecting Lamb waves with broadband acousto-ultrasonic signals in composite structures

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and lowest antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave disperison curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMCs, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  20. Acousto-ultrasonic verification of the strength of filament wound composite material

    NASA Technical Reports Server (NTRS)

    Kautz, H. E.

    1986-01-01

    The concept of acousto-ultrasonic (AU) waveform partitioning was applied to nondestructive evaluation of mechanical properties in filament wound composites (FWC). A series of FWC test specimens were subjected to AU analysis and the results were compared with destructively measured interlaminar shear strengths (ISS). AU stress-wave factor (SWF) measurements gave greater than 90 percent correlation coefficient upon regression against the ISS. This high correlation was achieved by employing the appropriate time and frequency domain partitioning as dictated by wave propagation path analysis. There is indication that different SWF frequency partitions are sensitive to ISS at different depths below the surface.

  1. Detecting Lamb waves with broadband acousto-ultrasonic signals in composite structures

    NASA Astrophysics Data System (ADS)

    Kautz, Harold E.

    1992-09-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and lowest antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave disperison curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMCs, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  2. An optimal baseline selection methodology for data-driven damage detection and temperature compensation in acousto-ultrasonics

    NASA Astrophysics Data System (ADS)

    Torres-Arredondo, M.-A.; Sierra-Pérez, Julián; Cabanes, Guénaël

    2016-05-01

    The process of measuring and analysing the data from a distributed sensor network all over a structural system in order to quantify its condition is known as structural health monitoring (SHM). For the design of a trustworthy health monitoring system, a vast amount of information regarding the inherent physical characteristics of the sources and their propagation and interaction across the structure is crucial. Moreover, any SHM system which is expected to transition to field operation must take into account the influence of environmental and operational changes which cause modifications in the stiffness and damping of the structure and consequently modify its dynamic behaviour. On that account, special attention is paid in this paper to the development of an efficient SHM methodology where robust signal processing and pattern recognition techniques are integrated for the correct interpretation of complex ultrasonic waves within the context of damage detection and identification. The methodology is based on an acousto-ultrasonics technique where the discrete wavelet transform is evaluated for feature extraction and selection, linear principal component analysis for data-driven modelling and self-organising maps for a two-level clustering under the principle of local density. At the end, the methodology is experimentally demonstrated and results show that all the damages were detectable and identifiable.

  3. The Influence of Finite-size Sources in Acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Pavlakovic, Brian N.; Rose, Joseph L.

    1994-01-01

    This work explores the effects that the finite normal axisymmetric traction loading of an infinite isotropic plate has on wave propagation in acousto-ultrasonics (AU), in which guided waves are created using two normal incidence transducers. Although the work also addresses the effects of the transducer pressure distribution and pulse shape, this thesis concentrates on two main questions: how does the transducer's diameter control the phase velocity and frequency spectrum of the response, and how does the plate thickness relate to the plate's excitability? The mathematics of the time-harmonic solution and the physical principles and the practical considerations for AU wave generation are explained. Transient sources are modeled by the linear superposition of the time-harmonic solutions found using the Hankel transform and they are then compared to experimental data to provide insight into the relation between the size of the transducer and the preferred phase velocity.

  4. Acousto-Ultrasonic analysis of failure in ceramic matrix composite tensile specimens

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.; Chulya, Abhisak

    1993-01-01

    Three types of acousto-ultrasonic (AU) measurements, stress-wave factor (SWF), lowest antisymmetric plate mode group velocity (VS), and lowest symmetric plate mode group velocity (VL), were performed on specimens before and after tensile failure. Three different Nicalon fiber architectures with ceramic matrices were tested. These composites were categorized as 1D (unidirectional fiber orientation) SiC/CAS glass ceramic, and 2D and 3D woven SiC/SiC ceramic matrix materials. SWF was found to be degraded after tensile failure in all three material categories. VS was found to be degraded only in the 1D SiC/CAS. VL was difficult to determine on the irregular specimen surfaces but appeared unchanged on all failed specimens. 3D woven specimens with heat-treatment at high temperature exhibited degradation only in SWF.

  5. An acoustic emission and acousto-ultrasonic analysis of impact damaged composite pressure vessels

    NASA Technical Reports Server (NTRS)

    Workman, Gary L. (Principal Investigator); Walker, James L.

    1996-01-01

    The use of acoustic emission to characterize impact damage in composite structures is being performed on composite bottles wrapped with graphite epoxy and kevlar bottles. Further development of the acoustic emission methodology will include neural net analysis and/or other multivariate techniques to enhance the capability of the technique to identify dominant failure mechanisms during fracture. The acousto-ultrasonics technique will also continue to be investigated to determine its ability to predict regions prone to failure prior to the burst tests. Characterization of the stress wave factor before, and after impact damage will be useful for inspection purposes in manufacturing processes. The combination of the two methods will also allow for simple nondestructive tests capable of predicting the performance of a composite structure prior to its being placed in service and during service.

  6. Acoustic emission and acousto-ultrasonic signature analysis of failure mechanisms in carbon fiber reinforced polymer materials

    NASA Astrophysics Data System (ADS)

    Carey, Shawn Allen

    Fiber reinforced polymer composite materials, particularly carbon (CFRPs), are being used for primary structural applications, particularly in the aerospace and naval industries. Advantages of CFRP materials, compared to traditional materials such as steel and aluminum, include: light weight, high strength to weight ratio, corrosion resistance, and long life expectancy. A concern with CFRPs is that despite quality control during fabrication, the material can contain many hidden internal flaws. These flaws in combination with unseen damage due to fatigue and low velocity impact have led to catastrophic failure of structures and components. Therefore a large amount of research has been conducted regarding nondestructive testing (NDT) and structural health monitoring (SHM) of CFRP materials. The principal objective of this research program was to develop methods to characterize failure mechanisms in CFRP materials used by the U.S. Army using acoustic emission (AE) and/or acousto-ultrasonic (AU) data. Failure mechanisms addressed include fiber breakage, matrix cracking, and delamination due to shear between layers. CFRP specimens were fabricated and tested in uniaxial tension to obtain AE and AU data. The specimens were designed with carbon fibers in different orientations to produce the different failure mechanisms. Some specimens were impacted with a blunt indenter prior to testing to simulate low-velocity impact. A signature analysis program was developed to characterize the AE data based on data examination using visual pattern recognition techniques. It was determined that it was important to characterize the AE event , using the location of the event as a parameter, rather than just the AE hit (signal recorded by an AE sensor). A back propagation neural network was also trained based on the results of the signature analysis program. Damage observed on the specimens visually with the aid of a scanning electron microscope agreed with the damage type assigned by the

  7. Ray propagation path analysis of acousto-ultrasonic signals in composites

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1987-01-01

    The most important result was the demonstration that acousto-ultrasonic (AU) energy introduced into a laminated graphite/resin propagates by two modes through the structure. The first mode, along the graphite fibers, is the faster. The second mode, through the resin matrix, besides being slower is also more strongly attenuated at the higher frequencies. This demonstration was accomplished by analyzing the time and frequency domain of the composite AU signal and comparing them to the same for a neat resin specimen of the same chemistry and geometry as the composite matrix. Analysis of the fine structure of AU spectra was accomplished by various geometrical strategies. It was shown that the multitude of narrow peaks associated with AU spectra are the effect of the many pulse arrivals in the signal. The shape and distribution of the peaks is mainly determined by the condition of nonnormal reflections of ray paths. A cepstrum analysis was employed which can be useful in detecting characteristic times. Analysis of propagation modes can be accomplished while ignoring the fine structure.

  8. A physical model for the acousto-ultrasonic method. Ph.D. Thesis Final Report

    NASA Technical Reports Server (NTRS)

    Kiernan, Michael T.; Duke, John C., Jr.

    1990-01-01

    A basic physical explanation, a model, and comments on NDE application of the acousto-ultrasonic (AU) method for composite materials are presented. The basis of this work is a set of experiments where a sending and a receiving piezoelectric transducer were both oriented normal to the surface, at different points, on aluminum plates, various composite plates, and a tapered aluminum plate. The purpose and basic idea is introduced. Also, general comments on the AU method are offered. A literature review is offered for areas pertinent, such as composite materials, wave propagation, ultrasonics, and the AU. Special emphasis is given to theory which is used later on and past experimental results that are important to the physical understanding of the AU method. The experimental set-up, procedure, and the ensuing analysis are described. The experimental results are presented in both a quantitative and qualitative manner. A physical understanding of experimental results based on elasticity solution is furnished. Modeling and applications of the AU method is discussed for composite material and general conclusions are stated. The physical model of the AU method for composite materials is offered, something which has been much needed and sorely lacking. This physical understanding is possible due to the extensive set of experimental measurements, also reported.

  9. Real time acousto-ultrasonic NDE technique for monitoring damage in ceramic composites under dynamic loads

    NASA Technical Reports Server (NTRS)

    Tiwari, Anil

    1995-01-01

    Research effort was directed towards developing a near real-time, acousto-ultrasonic (AU), nondestructive evaluation (NDE) tool to study the failure mechanisms of ceramic composites. Progression of damage is monitored in real-time by observing the changes in the received AU signal during the actual test. During the real-time AU test, the AU signals are generated and received by the AU transducers attached to the specimen while it is being subjected to increasing quasi-static loads or cyclic loads (10 Hz, R = 1.0). The received AU signals for 64 successive pulses were gated in the time domain (T = 40.96 micro sec) and then averaged every second over ten load cycles and stored in a computer file during fatigue tests. These averaged gated signals are representative of the damage state of the specimen at that point of its fatigue life. This is also the first major attempt in the development and application of real-time AU for continuously monitoring damage accumulation during fatigue without interrupting the test. The present work has verified the capability of the AU technique to assess the damage state in silicon carbide/calcium aluminosilicate (SiC/CAS) and silicon carbide/ magnesium aluminosilicate (SiC/MAS) ceramic composites. Continuous monitoring of damage initiation and progression under quasi-static ramp loading in tension to failure of unidirectional and cross-ply SiC/CAS and quasi-isotropic SiC/MAS ceramic composite specimens at room temperature was accomplished using near real-time AU parameters. The AU technique was shown to be able to detect the stress levels for the onset and saturation of matrix cracks, respectively. The critical cracking stress level is used as a design stress for brittle matrix composites operating at elevated temperatures. The AU technique has found that the critical cracking stress level is 10-15% below the level presently obtained for design purposes from analytical models. An acousto-ultrasonic stress-strain response (AUSSR) model

  10. Classification of Low Velocity Impactors Using Spiral Sensing of Acousto-Ultrasonic Waves

    NASA Astrophysics Data System (ADS)

    Agbasi, Chijioke Raphael

    The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from nonlinearity and variability in the AUS signals due to materials, geometry, boundary conditions, wave dispersion, environmental conditions, sensor and hardware calibration etc. It is found that the frequency and speed of the guided wave generated in the plate can be quantized based on the impactor's relationship with the plate (i.e. the wave speed and the impactor's mechanical properties are coupled). In this work, in order to characterize the impact location and mechanical properties of imapctors, nonlinear transient phenomenon is empirically studied to decouple the understanding using the dominant frequency band (DFB) and Lag Index (LI) of the acousto-ultrasonic signals. Next the understanding was correlated with the elastic modulus of the impactor to predict transmitted force histories. The proposed method presented in this thesis is especially applicable for SHM where sensors cannot be widely or randomly distributed. Thus a strategic organization and localization of the sensors is achieved by implementing the geometric configuration of Theodorous Spiral Sensor Cluster (TSSC). The performance of TSSC in characterizing the impactor types are compared with other conventional sensor clusters (e.g. square, circular, random etc.) and it is shown that the TSSC is advantageous over

  11. Applications of a nanocomposite-inspired in-situ broadband ultrasonic sensor to acousto-ultrasonics-based passive and active structural health monitoring.

    PubMed

    Liu, Menglong; Zeng, Zhihui; Xu, Hao; Liao, Yaozhong; Zhou, Limin; Zhang, Zhong; Su, Zhongqing

    2017-03-14

    A novel nanocomposite-inspired in-situ broadband ultrasonic sensor previously developed, with carbon black as the nanofiller and polyvinylidene fluoride as the matrix, was networked for acousto-ultrasonic wave-based passive and active structural health monitoring (SHM). Being lightweight and small, this kind of sensor was proven to be capable of perceiving strain perturbation in virtue of the tunneling effect in the formed nanofiller conductive network when acousto-ultrasonic waves traverse the sensor. Proof-of-concept validation was implemented, to examine the sensor performance in responding to acousto-ultrasonic waves in a broad frequency regime: from acoustic emission (AE) of lower frequencies to guided ultrasonic waves (GUWs) of higher frequencies. Results have demonstrated the high fidelity, ultrafast response and high sensitivity of the sensor to acousto-ultrasonic waves up to 400kHz yet with an ultra-low magnitude (of the order of micro-strain). The sensor is proven to possess sensitivity and accuracy comparable with commercial piezoelectric ultrasonic transducers, whereas with greater flexibility in accommodating curved structural surfaces. Application paradigms of using the sensor for damage evaluation have spotlighted the capability of the sensor in compromising "sensing cost" with "sensing effectiveness" for passive AE- or active GUW-based SHM.

  12. On the design of acousto-ultrasonics-pattern recognition classifiers for the identification of material response states

    SciTech Connect

    Haddad, Y.M.; Molina, G.J.

    1998-12-31

    This paper deals with the design procedure of computer-based Pattern Recognition (PR) Classifiers, when the Acousto-Ultrasonics (AU) technique is employed for the identification of material response states. For this purpose, material specimens presenting different mechanical response states are processed to retrieve AU signals in the form of digitalized records. The retrieved AU data are, then, grouped in distinct classes, each pertaining to a known response state of the material under consideration. These AU data are, subsequently, identified by pattern vectors, the components of which represent values of characteristic features in certain domains of description. PR-classifiers built from these pattern vectors are subsequently used to identify unknown response states of the material by classifying their pertaining AU signals as belonging to one of the predefined classes. In the paper, AU-experimental work in conjunction with PR-computational results are presented to illustrate the design procedure and testing of PR-classifiers for the purpose of identifying various low-energy repeated-impact states of a class of polymeric material; namely, Polyvinylchloride (PVC).

  13. Determination of plate wave velocities and diffuse field decay rates with braod-band acousto-ultrasonic signals

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1993-01-01

    Lowest symmetric and lowest antisymmetric plate wave modes were excited and identified in broad-band acousto-ultrasonic (AU) signals collected from various high temperature composite materials. Group velocities have been determined for these nearly nondispersive modes. An algorithm has been developed and applied to determine phase velocities and hence dispersion curves for the frequency ranges of the broad-band pulses. It is demonstrated that these data are sensitive to changes in the various stiffness moduli of the materials, in agreement by analogy, with the theoretical and experimental results of Tang and Henneke on fiber reinforced polymers. Diffuse field decay rates have been determined in the same specimen geometries and AU configuration as for the plate wave measurements. These decay rates are of value in assessing degradation such as matrix cracking in ceramic matrix composites. In addition, we verify that diffuse field decay rates respond to fiber/matrix interfacial shear strength and density in ceramic matrix composites. This work shows that velocity/stiffness and decay rate measurements can be obtained in the same set of AU experiments for characterizing materials and in specimens with geometries useful for mechanical measurements.

  14. Evaluation of fatigue cracks using nonlinearities of acousto-ultrasonic waves acquired by an active sensor network

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Hong, Ming; Su, Zhongqing; Wang, Qiang; Cheng, Li

    2013-01-01

    There has been increasing interest in using the nonlinear features of acousto-ultrasonic (AU) waves to detect damage onset (e.g., micro-fatigue cracks) due to their high sensitivity to damage with small dimensions. However, most existing approaches are able to infer the existence of fatigue damage qualitatively, but fail to further ascertain its location and severity. A damage characterization approach, in conjunction with the use of an active piezoelectric sensor network, was established, capable of evaluating fatigue cracks in a quantitative manner (including the co-presence of multiple fatigue cracks, and their individual locations and severities). Fundamental investigations, using both experiment and enhanced finite element analysis dedicated to the simulation of nonlinear AU waves, were carried out to link the accumulation of nonlinearities extracted from high-order AU waves to the characteristic parameters of a fatigue crack. A probability-based diagnostic imaging algorithm was developed, facilitating an intuitive presentation of identification results in images. The approach was verified experimentally by evaluating multi-fatigue cracks near rivet holes of a fatigued aluminum plate, showing satisfactory precision in characterizing real, barely visible fatigue cracks. Compared with existing methods, this approach innovatively (i) uses permanently integrated active sensor networks, conducive to automatic and online health monitoring; (ii) characterizes fatigue cracks at a quantitative level; (iii) allows detection of multiple fatigue cracks; and (iv) visualizes identification results in intuitive images.

  15. An Integrated Acousto/Ultrasonic Structural Health Monitoring System for Composite Pressure Vessels.

    PubMed

    Bulletti, Andrea; Giannelli, Pietro; Calzolai, Marco; Capineri, Lorenzo

    2016-06-01

    This paper describes the implementation of a structural health monitoring (SHM) method for mechanical components and structures in composite materials with a focus on carbon-fiber-overwrapped pressure vessels (COPVs) used in the aerospace industry. Two flex arrays of polyvinylidene fluoride (PVDF) interdigital transducers have been designed, realized, and mounted on the COPV to generate guided Lamb waves (mode A0) for damage assessment. We developed a custom electronic instrument capable of performing two functions using the same transducers: passive-mode detection of impacts and active-mode damage assessment using Lamb waves. The impact detection is based on an accurate evaluation of the time of arrival and was successfully tested with low-velocity impacts (7 and 30 J). Damage detection and progression is based on the calculation of a damage index matrix which compares a set of signals acquired from the transducers with a baseline. This paper also investigates the advantage of tuning the active-mode frequency to obtain the maximum transducer response in the presence of structural variations of the specimen, and therefore, the highest sensitivity to damage.

  16. An Integrated Acousto/Ultrasonic Structural Health Monitoring System for Composite Pressure Vessels.

    PubMed

    Bulletti, Andrea; Giannelli, Pietro; Calzolai, Marco; Capineri, Lorenzo

    2016-03-23

    This paper describes the implementation of a Structural Health Monitoring (SHM) method for mechanical components and structures in composite materials with a focus on Carbon Fiber Overwrapped Pressure Vessels (COPV) used in the aerospace industry. Two flex arrays of PVDF interdigital transducers have been designed, realized and mounted on the COPV to generate guided Lamb waves (mode A0) for damage assessment. We developed a custom electronic instrument capable of performing two functions using the same transducers: passive mode detection of impacts and active mode damage assessment using Lamb waves. The impact detection is based on an accurate evaluation of the time of arrival and was successfully tested with low-velocity impacts (7J and 30J). Damage detection and progression is based on the calculation of a Damage Index matrix which compares a set of signals acquired from the transducers with a baseline. The paper also investigates the advantage of tuning the active mode frequency to obtain the maximum transducer response in the presence of structural variations of the specimen, and therefore the highest sensitivity to damage.

  17. In-situ acousto-ultrasonic monitoring of crack propagation in Al2024 alloy

    NASA Astrophysics Data System (ADS)

    Vanniamparambil, Prashanth A.; Bartoli, Ivan; Hazeli, Kavan; Cuadra, Jefferson; Schwartz, Eric; Saralaya, Raghavendra; Kontsos, Antonios

    2012-04-01

    A data fusion technique implementing the principles of acoustic emission (AE), ultrasonic testing (UT) and digital image correlation (DIC) was employed to in situ monitor crack propagation in an Al 2024 alloy compact tension (CT) specimen. The specimen was designed according to ASTM E647-08 and was pre-cracked under fatigue loading to ensure stable crack growth. Tensile (Mode I) loads were applied according to ASTM E1290-08 while simultaneously recording AE activity, transmitting ultrasonic pulses and measuring full-field surface strains. Realtime 2D source location AE algorithms and visualization provided by the DIC system allowed the full quantification of the crack growth and the cross-validation of the recorded non-destructive testing data. In post mortem, waveform features sensitive to crack propagation were extracted and visible trends as a function of computed crack length were observed. In addition, following a data fusion approach, features from the three independent monitoring systems were combined to define damage sensitive correlations. Furthermore a novelty detector based on the Mahalanobis outlier analysis was implemented to quantify the extent of crack growth and to define a more robust sensing basis for the proposed system.

  18. Experimental investigation on acousto-ultrasonic sensing using polarization-maintaining fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Banks, Curtis E.; Wang, Gang

    2016-04-01

    This report discusses the guided Lamb wave sensing using polarization-maintaining (PM) fiber Bragg grating (PM-FBG) sensor. The goal is to apply the PM-FBG sensor system to composite structural health monitoring (SHM) applications in order to realize directivity and multi-axis strain sensing capabilities while reducing the number of sensors. Comprehensive experiments were conducted to evaluate the performance of the PM-FBG sensor attached to a composite panel structure under different actuation frequencies and locations. Three Macro-Fiber-Composite (MFC) piezoelectric actuators were used to generate guided Lamb waves that were oriented at 0, 45, and 90 degrees with respect to PMFBG axial direction, respectively. The actuation frequency was varied from 20 kHz to 200 kHz. It was shown that the PM-FBG sensor system was able to detect high-speed ultrasound waves and capture the characteristics under different actuation conditions. Both longitudinal and lateral strain components in the order of nano-strain were determined based on the reflective intensity measurement data from fast and slow axis of the PM fiber. It must be emphasized that this is the first attempt to investigate acouto-ultrasonic sensing using PM-FBG sensor. This could lead to a new sensing approach in the SHM applications.

  19. Experimental Investigation on Acousto-ultrasonic Sensing Using Polarization-Maintaining Fiber Bragg Gratings

    NASA Technical Reports Server (NTRS)

    Wang, Gag; Banks, Curtis E.

    2016-01-01

    This report discusses the guided Lamb wave sensing using polarization-maintaining (PM) fiber Bragg grating (PM-FBG) sensor. The goal is to apply the PM-FBG sensor system to composite structural health monitoring (SHM) applications in order to realize directivity and multi-axis strain sensing capabilities while reducing the number of sensors. Comprehensive experiments were conducted to evaluate the performance of the PM-FBG sensor attached to a composite panel structure under different actuation frequencies and locations. Three Macro-Fiber-Composite (MFC) piezoelectric actuators were used to generate guided Lamb waves that were oriented at 0, 45, and 90 degrees with respect to PM-FBG axial direction, respectively. The actuation frequency was varied from 20kHz to 200kHz. It was shown that the PM-FBG sensor system was able to detect high-speed ultrasound waves and capture the characteristics under different actuation conditions. Both longitudinal and lateral strain components in the order of nano-strain were determined based on the reflective intensity measurement data from fast and slow axis of the PM fiber. It must be emphasized that this is the first attempt to investigate acouto-ultrasonic sensing using PM-FBG sensor. This could lead to a new sensing approach in the SHM applications. Nomenclature.

  20. The development of an interpretive methodology for the application of real-time acousto-ultrasonic NDE technique for monitoring damage in ceramic composites under dynamic loads

    NASA Astrophysics Data System (ADS)

    Tiwari, Anil

    Research effort was directed towards developing a near real-time acousto-ultrasonic (AU), nondestructive evaluation (NDE) tool study the failure mechanisms of ceramic composites. Progression damage is monitored in real-time by observing the changes in the received AU signal during the actual test. During the real-time AU test the AU signals are generated and received by the AU transducers attached to the specimen while it is being subjected to increasing quasi static loads or cyclic loads (10 Hz, R = 0.1). The received AU signals for 64 successive pulses were gated in the time domain (T = 40.96) and then averaged every second over ten load cycles and store in a computer file during fatigue tests. These averaged gated signal are representative of the damage state of the specimen at that point c its fatigue life. This is also the first major attempt in the development and application of real-time AU for continuously monitoring damage accumulation during fatigue without interrupting the test. The present work has verified the capability of the AU technique to assess the damage state in silicon carbide/calcium aluminosilicatt (SiC/CAS) and silicon carbide/magnesium aluminosilicate (SiC/MAS) ceramic composites. Continuous monitoring of damage initiation and progression under quasi-static ramp loading in tension to failure of unidirectional and cross-ply SiC/CAS and quasi-isotropic SiC/MAS ceramic composite specimens at room temperature was accomplished using near real-time AU parameters. The AU technique was shown to be able to detect the stress levels for the onset and saturation of matrix cracks, respectively. The critical cracking stress level is used as a design stress for brittle matrix composites operating at elevated temperatures. The AU technique has found that the critical cracking stress level is 10-15 percent below the level presently obtained for design purposes from analytical models. An acousto-ultrasonic stress-strain response (AUSSR) model for

  1. Battery scanning system

    SciTech Connect

    Dieu, L.F.

    1984-11-20

    A battery scanning system which is capable of monitoring and displaying the voltage of each cell in a battery or upon command provides the cell voltage distribution by displaying the cell number and voltage value of highest and lowest cell. The system has a digital logic system, display, input switches for operator generated variables, an alarm, relays, relay selection gates, an optically coupled isolation amplifier, power source and an analog-digital converter. The optically coupled analog amplifier electrically isolates the system from the battery so that large voltage offsets will not adversely affect the automatic measuring of the cells.

  2. Free motion scanning system

    DOEpatents

    Sword, Charles K.

    2000-01-01

    The present invention relates to an ultrasonic scanner system and method for the imaging of a part system, the scanner comprising: a probe assembly spaced apart from the surface of the part including at least two tracking signals for emitting radiation and a transmitter for emitting ultrasonic waves onto a surface in order to induce at least a portion of the waves to be reflected from the part, at least one detector for receiving the radiation wherein the detector is positioned to receive the radiation from the tracking signals, an analyzer for recognizing a three-dimensional location of the tracking signals based on the emitted radiation, a differential converter for generating an output signal representative of the waveform of the reflected waves, and a device such as a computer for relating said tracking signal location with the output signal and projecting an image of the resulting data. The scanner and method are particularly useful to acquire ultrasonic inspection data by scanning the probe over a complex part surface in an arbitrary scanning pattern.

  3. 3D Scan Systems Integration

    DTIC Science & Technology

    2007-11-02

    AGENCY USE ONLY (Leave Blank) 2. REPORT DATE 5 Feb 98 4. TITLE AND SUBTITLE 3D Scan Systems Integration REPORT TYPE AND DATES COVERED...2-89) Prescribed by ANSI Std. Z39-1 298-102 [ EDO QUALITY W3PECTEDI DLA-ARN Final Report for US Defense Logistics Agency on DDFG-T2/P3: 3D...SCAN SYSTEMS INTEGRATION Contract Number SPO100-95-D-1014 Contractor Ohio University Delivery Order # 0001 Delivery Order Title 3D Scan Systems

  4. Adaptive CT scanning system

    SciTech Connect

    Sampayan, Stephen E.

    2016-11-22

    Apparatus, systems, and methods that provide an X-ray interrogation system having a plurality of stationary X-ray point sources arranged to substantially encircle an area or space to be interrogated. A plurality of stationary detectors are arranged to substantially encircle the area or space to be interrogated, A controller is adapted to control the stationary X-ray point sources to emit X-rays one at a time, and to control the stationary detectors to detect the X-rays emitted by the stationary X-ray point sources.

  5. Transverse section radionuclide scanning system

    DOEpatents

    Kuhl, David E.; Edwards, Roy Q.

    1976-01-01

    This invention provides a transverse section radionuclide scanning system for high-sensitivity quantification of brain radioactivity in cross-section picture format in order to permit accurate assessment of regional brain function localized in three-dimensions. High sensitivity crucially depends on overcoming the heretofore known raster type scanning, which requires back and forth detector movement involving dead-time or partial enclosure of the scan field. Accordingly, this invention provides a detector array having no back and forth movement by interlaced detectors that enclose the scan field and rotate as an integral unit around one axis of rotation in a slip ring that continuously transmits the detector data by means of laser emitting diodes, with the advantages that increased amounts of data can be continuously collected, processed and displayed with increased sensitivity according to a suitable computer program.

  6. High precision prism scanning system

    NASA Astrophysics Data System (ADS)

    García-Torales, G.; Flores, J. L.; Muñoz, Roberto X.

    2007-03-01

    Risley prisms are commonly used in continuous scanning manner. Each prism is capable of rotating separately about a common axis at different speeds. Scanning patterns are determined by the ratios of the wedge angles, the speed and direction of rotation of both prisms. The use of this system is conceptually simple. However, mechanical action in most applications becomes a challenge often solved by the design of complex control algorithms. We propose an electronic servomotor system that controls incremental and continuous rotations of the prisms wedges by means of an auto-tuning PID control using a Adaline Neural Network Algorithm, NNA.

  7. Scanning Terahertz Heterodyne Imaging Systems

    NASA Technical Reports Server (NTRS)

    Siegel, Peter; Dengler, Robert

    2007-01-01

    Scanning terahertz heterodyne imaging systems are now at an early stage of development. In a basic scanning terahertz heterodyne imaging system, (see Figure 1) two far-infrared lasers generate beams denoted the local-oscillator (LO) and signal that differ in frequency by an amount, denoted the intermediate frequency (IF), chosen to suit the application. The LO beam is sent directly to a mixer as one of two inputs. The signal beam is focused to a spot on or in the specimen. After transmission through or reflection from the specimen, the beams are focused to a spot on a terahertz mixer, which extracts the IF outputs. The specimen is mounted on a translation stage, by means of which the focal spot is scanned across the specimen to build up an image.

  8. SCAN+

    SciTech Connect

    Kenneth Krebs, John Svoboda

    2009-11-01

    SCAN+ is a software application specifically designed to control the positioning of a gamma spectrometer by a two dimensional translation system above spent fuel bundles located in a sealed spent fuel cask. The gamma spectrometer collects gamma spectrum information for the purpose of spent fuel cask fuel loading verification. SCAN+ performs manual and automatic gamma spectrometer positioning functions as-well-as exercising control of the gamma spectrometer data acquisitioning functions. Cask configuration files are used to determine the positions of spent fuel bundles. Cask scanning files are used to determine the desired scan paths for scanning a spent fuel cask allowing for automatic unattended cask scanning that may take several hours.

  9. Suspension system for gimbal supported scanning payloads

    NASA Technical Reports Server (NTRS)

    Polites, Michael E. (Inventor)

    1995-01-01

    Gimballed scanning devices or instruments are the subject of this invention. Scanning is an important aspect of space science. To achieve a scan pattern some means must be provided which impart to the payload an oscillatory motion. Various forms of machines have been employed for controllably conferring on scanning instruments predetermined scan patterns. They include control moment gyroscopes, reaction wheels, torque motors, reaction control systems, and the like. But rotating unbalanced mass (RUM) devices are a new and efficient way to generate scans in gimballed payloads. RUM devices are superior to previous scanning apparatus, but they require power consuming and frequently complex auxiliary control systems to position and reposition the particular scan pattern relative to a target or a number of targets. Herein the control system is simplified. The most frequently employed method for achieving the various scan patterns is to gimbal the scanning device. Gimbals are suspended in such a way that they can be activated to generate the scan pattern. The suspension means described is for payloads supported in gimbals wherein the payload rotation is restricted by a flex pivot so that the payload oscillates, thereby moving in a scan pattern.

  10. A microprocessor controlled pressure scanning system

    NASA Technical Reports Server (NTRS)

    Anderson, R. C.

    1976-01-01

    A microprocessor-based controller and data logger for pressure scanning systems is described. The microcomputer positions and manages data from as many as four 48-port electro-mechanical pressure scanners. The maximum scanning rate is 80 pressure measurements per second (20 ports per second on each of four scanners). The system features on-line calibration, position-directed data storage, and once-per-scan display in engineering units of data from a selected port. The system is designed to be interfaced to a facility computer through a shared memory. System hardware and software are described. Factors affecting measurement error in this type of system are also discussed.

  11. Compact scanning lidar systems using holographic optics

    NASA Astrophysics Data System (ADS)

    Schwemmer, Geary K.; Wilkerson, Thomas D.; Guerra, David

    1998-08-01

    Two scanning lidar systems have been built using holographic optical elements (HOE) that function as a scanning telescope primary optic. One is a ground based lidar using a reflection HOE, and uses a frequency doubled Nd:YAG laser transmitter. The other system is an airborne/ground based system that uses a transmission HOE and operates at the 1064 nm fundamental of the Nd:YAG laser. Each HOE has a focal spot on the center- line, normal to the flat disk holding the hologram, and a field of view (FOV) that points approximately 45 degrees from the normal. Rotating the disk effects a conical scan of the FOV. In both systems, the same HOE is also used to collimate and steer the transmitted laser beam. The utility of using the HOEs to save weight and size in scanning lidars is evidenced by the atmospheric backscatter data collected with these systems. They also will lower the cost of commercial systems due to the low cost of replicating HOEs and the simplified mechanical scanning systems. Development of airborne scanning lidar altimeters and other lidars and passive instruments using holographic optics are underway, including the development of a one meter diameter, space qualified holographic scanning telescope for use in the ultraviolet.

  12. Camera Systems Rapidly Scan Large Structures

    NASA Technical Reports Server (NTRS)

    2013-01-01

    Needing a method to quickly scan large structures like an aircraft wing, Langley Research Center developed the line scanning thermography (LST) system. LST works in tandem with a moving infrared camera to capture how a material responds to changes in temperature. Princeton Junction, New Jersey-based MISTRAS Group Inc. now licenses the technology and uses it in power stations and industrial plants.

  13. The design of laser scanning galvanometer system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  14. Scanning tunneling microscope assembly, reactor, and system

    SciTech Connect

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  15. ACTD Laser Line Scan System

    DTIC Science & Technology

    1997-09-30

    communications with a computer system in the MILVAN. For the ACTD a single board computer dedicated to the EOID Sensor will be inserted into GEM. This... single board computer will provide real time control of the EOID Sensor. Since the bandwidth of the microwave data link is smaller than the data rate of...EOID Sensor image data will be maintained in a circular buffer on the single board computer in GEM. Upon command, full resolution data from any segment

  16. Joule heating scanning structure system.

    PubMed

    Moya, J A

    2016-08-01

    A method and its system to study the structural evolution on soft magnetic amorphous and nanocrystalline ribbon shaped alloys are presented. With only one sample, a complete set of magnetic and electric data at room and at high temperature are obtained in a relatively short period of time, allowing us to elucidate the structural changes occurring in the alloy and to determine the optimal soft magnetic properties annealing conditions.

  17. Simple Cassegrain scanning system for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Apt, J.; Goody, R.; Mertz, L.

    1980-01-01

    To meet the need for a reliable, fast imaging system capable of being taken rapidly on and off the telescope, a simple, inexpensive, and compact Cassegrain reimaging system for scanning IR images was constructed. Using commercially available components without requiring close mechanical tolerances, the design solves the problem of beam stability pointed out by Koornneef and van Overbeeke (1976). For the moving-iron galvanometer scanner, it is noted that at the imaging frequency of 0.5 Hz, hysteresis in image plane motion was found to be less than 0.2 arc sec for a 64-arc sec scan, and the deviation from linearity with a triangular wave input was found to be less than 0.3 arc sec. This system and a scanning secondary were used to image Venus at 11.5 microns, and compared with the scanning secondary, the reimaging system did not appear to contribute any additional noise, considerably improved mechanical reliability, and eliminated cross-scan motion

  18. Scanning Gamma Ray Densitometer System for Detonations.

    DTIC Science & Technology

    in loaded detonators and delays. The 317 KEV gamma rays from an Ir192 source were collimated into a beam of 0.002 by 0.100 inch. A scanning system...minus 3%. With Ir192 , density measurements on NOL-130 were reproduced to plus or minus 5%, and on RDX to plus or minus 16%. Based on gamma ray

  19. CS-Studio Scan System Parallelization

    SciTech Connect

    Kasemir, Kay; Pearson, Matthew R

    2015-01-01

    For several years, the Control System Studio (CS-Studio) Scan System has successfully automated the operation of beam lines at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). As it is applied to additional beam lines, we need to support simultaneous adjustments of temperatures or motor positions. While this can be implemented via virtual motors or similar logic inside the Experimental Physics and Industrial Control System (EPICS) Input/Output Controllers (IOCs), doing so requires a priori knowledge of experimenters requirements. By adding support for the parallel control of multiple process variables (PVs) to the Scan System, we can better support ad hoc automation of experiments that benefit from such simultaneous PV adjustments.

  20. Cornea Optical Topographical Scan System (COTSS)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The Cornea Optical Topographical Scan System (COTSS) is an instrument designed for use by opthalmologist to aid in performing surgical procedures such as radial keratotomy and to provide quick accurate data to aid in prescribing contact lenses and eyeglasses. A breadboard of the system was built and demonstrated in June of 1984. Additional refinements to the breadboard are needed to meet systems requirements prior to proceeding with prototype development. The present status of the COTSS instrument is given and the areas in which system refinements are required, are defined.

  1. Cornea Optical Topographical Scan System (COTSS)

    NASA Astrophysics Data System (ADS)

    1986-08-01

    The Cornea Optical Topographical Scan System (COTSS) is an instrument designed for use by opthalmologist to aid in performing surgical procedures such as radial keratotomy and to provide quick accurate data to aid in prescribing contact lenses and eyeglasses. A breadboard of the system was built and demonstrated in June of 1984. Additional refinements to the breadboard are needed to meet systems requirements prior to proceeding with prototype development. The present status of the COTSS instrument is given and the areas in which system refinements are required, are defined.

  2. The design of scanning fiber optical system

    NASA Astrophysics Data System (ADS)

    Bai, Yangbo; Xiang, Wanghua; Zu, Peng; Li, Xu; Ren, Fang; Shi, Xiaozhou; Xu, Xiaoyan

    2009-11-01

    A novel scanning fiber optical system for multi-channel optical switch has been demonstrated. This scanning fiber system consists of motor, photoelectric encoder, EPOS position controller, Field Programmable Gate Array (FPGA), fiber laser, transmitting energy fiber bundle, reflector, five-dimensional optical adjustable mounts, etc. In this device, the control system is composed of EPOS position controller and FPGA. Furthermore, the photoelectric encoder is directly connected to the central shaft of the motor to read its position information. The reflector is slantways fixed on the other end of the motor central shaft. Also, the fiber bundle is fixed by optical adjustable mounts to achieve slight position adjustment, which is used as launching system of this configuration. In the operation process, the motor in uniform rotation state drives the photoelectric encoder and the reflector at the same angle velocity. The photoelectric encoder reads the incremental signal and absolute position signal of motor, and then sends them to EPOS position controller and FPGA respectively. FPGA sends square wave signal to the fiber laser under the control of EPOS position controller and FPGA. Triggered by the square wave signal, the fiber laser emits a laser pulse to the center point of the reflector. At the same time, the reflector makes the laser pulse transmitting into a certain transmitting energy fiber according to the angle of the reflector at that moment. Therefore, with the motor rotates at uniform speed, the laser pulse is sent to different fibers, by which multi-channel optical switch is completed.

  3. Intraoral scanning systems - a current overview.

    PubMed

    Zimmermann, M; Mehl, A; Mörmann, W H; Reich, S

    2015-01-01

    There is no doubt today about the possibilities and potential of digital impression-taking with the aid of intraoral optical impression systems, and the past few years have seen a considerable increase in the range of optical intraoral scanners available on the market. On the strength of numerous innovations and a wider range of indications in orthodontics and implantology, intraoral scanning systems appear to be a highly promising development for the future. Digital impression-taking with intraoral scanners has already shown itself in some respects to be clearly superior to conventional impression- taking. Particularly worthy of mention is the versatile integration of digital impressions into diagnostic and treatment concepts to provide a customizable healthcare solution for the patient. It remains exciting to look forward to future developments that will allow us to observe digital impression-taking--as with other digital applications already established in everyday life--becoming firmly established in the routine of dentistry and dental technology. This article presents an overview of the benefits and limitations of digital impression-taking using intraoral scanning systems, and includes a summary of all the relevant intraoral scanners available on the market at present.

  4. Scanning systems for particle cancer therapy

    DOEpatents

    Trbojevic, Dejan

    2015-08-04

    A particle beam to treat malignant tissue is delivered to a patient by a gantry. The gantry includes a plurality of small magnets sequentially arranged along a beam tube to transfer the particle beam with strong focusing and a small dispersion function, whereby a beam size is very small, allowing for the small magnet size. Magnets arranged along the beam tube uses combined function magnets where the magnetic field is a combination of a bending dipole field with a focusing or defocusing quadrupole field. A triplet set of combined function magnets defines the beam size at the patient. A scanning system of magnets arranged along the beam tube after the bending system delivers the particle beam in a direction normal to the patient, to minimize healthy skin and tissue exposure to the particle beam.

  5. Optical analysis of scanning microstereolithography systems

    NASA Astrophysics Data System (ADS)

    Deshmukh, Suhas P.; Dubey, Shashikant; Gandhi, P. S.

    2006-01-01

    Microstereolithography (MSL) is rapidly developing technique for micro-fabrication. Vector-by-vector scanning MSL has a potential to create true 3D micro-devices as compared to mostly planar (2D-2 1/2 D) devices fabricated by conventional MEMS techniques. Previous literature shows two different scanning methods:(1) Galvanomirror scanning, (2) Photoreactor tank scanning. Galvanomirror scanning technique has higher fabrication speed but poor resolution because of defocusing of laser spot on the resin surface. Photo-reactor tank scanning has higher resolution but produces a wavy structures and limited speed of fabrication. This paper proposes and develops an offaxis lens scanning technique for MSL and carries out optical analysis to compare its performance with the existing techniques mentioned above. The comparison clearly demonstrates improved performance with the proposed offaxis lens scanning technique.

  6. Environmental Scan for the Colorado Community College System.

    ERIC Educational Resources Information Center

    2003

    This document addresses an environmental scan done in the Colorado Community College System (CCCS). The goals of an environmental scan include collecting external information, predicting future trends, and analyzing how these trends might affect an organization. The environmental scan completed for the CCCS focused on emerging trends that may…

  7. Scanning high-Tc SQUID imaging system for magnetocardiography

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Chang; Wu, Tsung-Yeh; Horng, Herng-Er; Wu, Chau-Chung; Yang, S. Y.; Liao, Shu-Hsien; Wu, Chiu-Hsien; Jeng, J. T.; Chen, J. C.; Chen, Kuen-Lin; Chen, M. J.

    2006-05-01

    A scanning magnetocardiography (MCG) system constructed from SQUID sensors offers potential to basic or clinical research in biomagnetism. In this work, we study a first order scanning electronic high-Tc (HTS) SQUID MCG system for biomagnetic signals. The scanning MCG system was equipped with an x-y translation bed powered by step motors. Using noise cancellation and μ-metal shielding, we reduced the noise level substantially. The established scanning HTS MCG system was used to study the magnetophysiology of hypercholesterolaemic (HC) rabbits. The MCG data of HC rabbits were analysed. The MCG contour map of HC rabbits provides experimental models for the interpretation of human cardiac patterns.

  8. System and method for compressive scanning electron microscopy

    DOEpatents

    Reed, Bryan W

    2015-01-13

    A scanning transmission electron microscopy (STEM) system is disclosed. The system may make use of an electron beam scanning system configured to generate a plurality of electron beam scans over substantially an entire sample, with each scan varying in electron-illumination intensity over a course of the scan. A signal acquisition system may be used for obtaining at least one of an image, a diffraction pattern, or a spectrum from the scans, the image, diffraction pattern, or spectrum representing only information from at least one of a select subplurality or linear combination of all pixel locations comprising the image. A dataset may be produced from the information. A subsystem may be used for mathematically analyzing the dataset to predict actual information that would have been produced by each pixel location of the image.

  9. Laser scanning system for object monitoring

    DOEpatents

    McIntyre, Timothy James [Knoxville, TN; Maxey, Lonnie Curtis [Powell, TN; Chiaro, Jr; John, Peter [Clinton, TN

    2008-04-22

    A laser scanner is located in a fixed position to have line-of-sight access to key features of monitored objects. The scanner rapidly scans pre-programmed points corresponding to the positions of retroreflecting targets affixed to the key features of the objects. The scanner is capable of making highly detailed scans of any portion of the field of view, permitting the exact location and identity of targets to be confirmed. The security of an object is verified by determining that the cooperative target is still present and that its position has not changed. The retroreflecting targets also modulate the reflected light for purposes of returning additional information back to the location of the scanner.

  10. Speckle averaging system for laser raster-scan image projection

    DOEpatents

    Tiszauer, Detlev H.; Hackel, Lloyd A.

    1998-03-17

    The viewers' perception of laser speckle in a laser-scanned image projection system is modified or eliminated by the addition of an optical deflection system that effectively presents a new speckle realization at each point on the viewing screen to each viewer for every scan across the field. The speckle averaging is accomplished without introduction of spurious imaging artifacts.

  11. PSIDD: A Post-Scan Interactive Data Display System for Ultrasonic Scans

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Szatmary, Steven A.

    1993-01-01

    An ultrasonic data display system was developed at NASA Lewis Research Center that allows the user to interactively examine digitized waveforms and processed information associated with any specific scan location of an ultrasonic contact scan. This information is displayed on a video display monitor and includes acquired time-domain waveforms, frequency-domain magnitude and phase spectra, and ultrasonic properties (pulse velocity, phase velocity, reflection coefficient, attenuation coefficient, attenuation coefficient error) as a function of frequency for a material. This report describes the system features and illustrates the system's usefulness for nondestructive materials characterization.

  12. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system

    SciTech Connect

    Lewis, David; Devic, Slobodan

    2015-10-15

    Purpose: In radiochromic film dosimetry systems, measurements are usually obtained from film images acquired on a CCD-based flatbed scanner. The authors investigated factors affecting scan-to-scan response variability leading to increased dose measurement uncertainty. Methods: The authors used flatbed document scanners to repetitively scan EBT3 radiochromic films exposed to doses 0–1000 cGy, together with three neutral density filters and three blue optical filters. Scanning was performed under two conditions: scanner lid closed and scanner lid opened/closed between scans. The authors also placed a scanner in a cold room at 9 °C and later in a room at 22 °C and scanned EBT3 films to explore temperature effects. Finally, the authors investigated the effect of altering the distance between the film and the scanner’s light source. Results: Using a measurement protocol to isolate the contribution of the CCD and electronic circuitry of the scanners, the authors found that the standard deviation of response measurements for the EBT3 film model was about 0.17% for one scanner and 0.09% for the second. When the lid of the first scanner was opened and closed between scans, the average scan-to-scan difference of responses increased from 0.12% to 0.27%. Increasing the sample temperature during scanning changed the RGB response values by about −0.17, −0.14, and −0.05%/°C, respectively. Reducing the film-to-light source distance increased the RBG response values about 1.1, 1.3, and 1.4%/mm, respectively. The authors observed that films and film samples were often not flat with some areas up to 8 mm away from the scanner’s glass window. Conclusions: In the absence of measures to deal with the response irregularities, each factor the authors investigated could lead to dose uncertainty >2%. Those factors related to the film-to-light source distance could be particularly impactful since the authors observed many instances where the curl of film samples had the

  13. Rapid scanning system for fuel drawers

    DOEpatents

    Caldwell, John T.; Fehlau, Paul E.; France, Stephen W.

    1981-01-01

    A nondestructive method for uniqely distinguishing among and quantifying the mass of individual fuel plates in situ in fuel drawers utilized in nuclear reactors is described. The method is both rapid and passive, eliminating the personnel hazard of the commonly used irradiation techniques which require that the analysis be performed in proximity to an intense neutron source such as a reactor. In the present technique, only normally decaying nuclei are observed. This allows the analysis to be performed anywhere. This feature, combined with rapid scanning of a given fuel drawer (in approximately 30 s), and the computer data analysis allows the processing of large numbers of fuel drawers efficiently in the event of a loss alert.

  14. Rapid scanning system for fuel drawers

    DOEpatents

    Caldwell, J.T.; Fehlau, P.E.; France, S.W.

    A nondestructive method for uniquely distinguishing among and quantifying the mass of individual fuel plates in situ in fuel drawers utilized in nuclear reactors is described. The method is both rapid and passive, eliminating the personnel hazard of the commonly used irradiation techniques which require that the analysis be performed in proximity to an intense neutron source such as a reactor. In the present technique, only normally decaying nuclei are observed. This allows the analysis to be performed anywhere. This feature, combined with rapid scanning of a given fuel drawer (in approximately 30 s), and the computer data analysis allows the processing of large numbers of fuel drawers efficiently in the event of a loss alert.

  15. Stereo vision based hand-held laser scanning system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Wang, Jinming

    2011-11-01

    Although 3D scanning system is used more and more broadly in many fields, such computer animate, computer aided design, digital museums, and so on, a convenient scanning device is expansive for most people to afford. In another hand, imaging devices are becoming cheaper, a stereo vision system with two video cameras cost little. In this paper, a hand held laser scanning system is design based on stereo vision principle. The two video cameras are fixed tighter, and are all calibrated in advance. The scanned object attached with some coded markers is in front of the stereo system, and can be changed its position and direction freely upon the need of scanning. When scanning, the operator swept a line laser source, and projected it on the object. At the same time, the stereo vision system captured the projected lines, and reconstructed their 3D shapes. The code markers are used to translate the coordinate system between scanned points under different view. Two methods are used to get more accurate results. One is to use NURBS curves to interpolate the sections of the laser lines to obtain accurate central points, and a thin plate spline is used to approximate the central points, and so, an exact laser central line is got, which guards an accurate correspondence between tow cameras. Another way is to incorporate the constraint of laser swept plane on the reconstructed 3D curves by a PCA (Principle Component Analysis) algorithm, and more accurate results are obtained. Some examples are given to verify the system.

  16. Area scanning vision inspection system by using mirror control

    NASA Astrophysics Data System (ADS)

    Jeong, Sang Y.; Min, Sungwook; Yang, Wonyoung

    2001-02-01

    12 As the pressure increases to deliver vision products with faster speed while inspection higher resolution at lower cost, the area scanning vision inspection system can be one of the good solutions. To inspect large area with high resolution, the conventional vision system requires moving either camera or the target, therefore, the system suffers low speed and high cost due to the requirements of mechanical moving system or higher resolution camera. Because there are only tiny mirror angle movements required to change the field of view, the XY mirror controlled area scanning vision system is able to capture random area images with high speed. Elimination of external precise moving mechanism is another benefit of the mirror control. The image distortion due to the lens and the mirror system shall be automatically compensated right after each image captured so that the absolute coordination can be calculated in real- time. Motorized focusing system is used for the large area inspection, so that the proper focusing achieved for the variable working distance between lens and targets by the synchronization to the mirror scanning system. By using XY mirror controlled area scanning vision inspection system, fast and economic system can be integrated while no vibration induced and smaller space required. This paper describes the principle of the area scanning method, optical effects of the scanning, position calibration method, inspection flows and some of implementation results.

  17. Ultrasonic scanning system for inspection of brazed tube joints

    NASA Technical Reports Server (NTRS)

    Haynes, J. L.; Maurer, N. A.

    1972-01-01

    An ultrasonic scanning system used to inspect and evaluate in-place brazed tube joints is considered. The system was designed, developed, and built especially for nondestructive testing and was selected because of its known response to brazing defects not associated with material density changes. The scan system is capable of scanning brazed joints in union, tee, elbow and cross configuration of 3/16-inch through 5/8-inch diameters. It is capable of detecting brazed defects as small as 0.008 by 0.010-inch, which exceeds the 0.015-inch diameter defect resolution required by specification.

  18. Pneumatic preloaded scanning science launch latch system

    NASA Technical Reports Server (NTRS)

    Kievit, J. C.

    1979-01-01

    A relatively simple system using a preloaded pneumatic piston latch with a pyrotechnic valve release was developed. The system was the only candidate that met all the imposed requirements utilizing reliable state-of-art components. The development of the latch system from its first use on Mariner '69 Mars Flyby Spacecraft through its most recent use on the Voyager Spacecraft that will fly to Jupiter and Saturn is reviewed.

  19. New superconducting cyclotron driven scanning proton therapy systems

    NASA Astrophysics Data System (ADS)

    Klein, Hans-Udo; Baumgarten, Christian; Geisler, Andreas; Heese, Jürgen; Hobl, Achim; Krischel, Detlef; Schillo, Michael; Schmidt, Stefan; Timmer, Jan

    2005-12-01

    Since one and a half decades ACCEL is investing in development and engineering of state of the art particle-therapy systems. A new medical superconducting 250 MeV proton cyclotron with special focus on the present and future beam requirements of fast scanning treatment systems has been designed. The first new ACCEL medical proton cyclotron is under commissioning at PSI for their PROSCAN proton therapy facility having undergone successful factory tests especially of the closed loop cryomagnetic system. The second cyclotron is part of ACCEL's integrated proton therapy system for Europe's first clinical center, RPTC in Munich. The cyclotron, the energy selection system, the beamline as well as the four gantries and patient positioners have been installed. The scanning system and major parts of the control software have already been tested. We will report on the concept of ACCEL's superconducting cyclotron driven scanning proton therapy systems and the current status of the commissioning work at PSI and RPTC.

  20. Tuning and scanning control system for high resolution alexandrite lasers

    NASA Technical Reports Server (NTRS)

    Smith, James C.; Schwemmer, Geary K.

    1988-01-01

    An alexandrite laser is spectrally narrowed and tuned by the use of three optical elements. Each element provides a successively higher degree of spectral resolution. The digitally controlled tuning and scanning control servo system simultaneously positions all three optical elements to provide continuous high resolution laser spectral tuning. The user may select manual, single, or continuous modes of automated scanning of ranges up to 3.00/cm and at scan rates up to 3.85/cm/min. Scanning over an extended range of up to 9.999/cm may be achieved if the highest resolution optic is removed from the system. The control system is also capable of being remotely operated by another computer or controller via standard RS-232 serial data link.

  1. A new spherical scanning system for infrared reflectography of paintings

    NASA Astrophysics Data System (ADS)

    Gargano, M.; Cavaliere, F.; Viganò, D.; Galli, A.; Ludwig, N.

    2017-03-01

    Infrared reflectography is an imaging technique used to visualize the underdrawings of ancient paintings; it relies on the fact that most pigment layers are quite transparent to infrared radiation in the spectral band between 0.8 μm and 2.5 μm. InGaAs sensor cameras are nowadays the most used devices to visualize the underdrawings but due to the small size of the detectors, these cameras are usually mounted on scanning systems to record high resolution reflectograms. This work describes a portable scanning system prototype based on a peculiar spherical scanning system built through a light weight and low cost motorized head. The motorized head was built with the purpose of allowing the refocusing adjustment needed to compensate the variable camera-painting distance during the rotation of the camera. The prototype has been tested first in laboratory and then in-situ for the Giotto panel "God the Father with Angels" with a 256 pixel per inch resolution. The system performance is comparable with that of other reflectographic devices with the advantage of extending the scanned area up to 1 m × 1 m, with a 40 min scanning time. The present configuration can be easily modified to increase the resolution up to 560 pixels per inch or to extend the scanned area up to 2 m × 2 m.

  2. New acousto-ultrasonic techniques applied to aerospace materials

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    The use of an NdYAG pulsed laser for generating ultrasonic waves for NDE in resin matrix composites was investigated. A study was conducted of the use of the 1.064 micron wavelength NdYAG pulsed laser with the neat, unreinforced resin as well as graphite fiber/polymer composite specimens. In the case of the neat resins it was found that, at normal incidence, about 25 percent of the laser pulse energy was reflected at the incident surface. An attenuation coefficient for the polyimide resin, PMR-15 was determined to be approximately 5.8 np/cm. It was found in energy balance studies that graphite fiber/polymer specimens attenuate the laser beam more than do neat resins. The increase absorption is in the graphite fibers. The occurrence of laser induced surface damage was also studied. For the polymer neat resin, damage appears as pit formation over a small fraction of the pulse impact area and discoloration over a larger part of the area. A damage threshold was inferred from observed damage as a function of pulse energy. The 600 F cured PMR-15 and PMR-11 exhibit about the same amount of damage for a given laser pulse energy. The damage threshold is between 0.06 and 0.07 J/sq cm.

  3. Pencil Beam Scanning System Based On A Cyclotron

    SciTech Connect

    Tachikawa, Toshiki; Nonaka, Hideki; Kumata, Yukio; Nishio, Teiji; Ogino, Takashi

    2011-06-01

    Sumitomo Heavy Industries, Ltd. (SHI) has developed a new pencil beam scanning system (PBS) for proton therapy in collaboration with National Cancer Center Hospital East (NCCHE). Taking advantage of the continuous beam from the cyclotron P235, the line scanning method is employed in order to realize continuous irradiation with high dose rate. 3D uniform and sphere field was irradiated and compared with the simulation.

  4. Optics designs and system MTF for laser scanning displays

    NASA Astrophysics Data System (ADS)

    Urey, Hakan; Nestorovic, Ned; Ng, Baldwin S.; Gross, Abraham A.

    1999-07-01

    The Virtual Retinal DisplayTM (VRDTM) technology is a new display technology being developed at Microvision Inc. The displayed image is scanned onto the viewer's retina using low- power red, green, and blue light sources. Microvision's proprietary miniaturized scanner designs make VRD system very well suited for head-mounted displays. In this paper we discuss some of the advantages of the VRD technology, various ocular designs for HMD and other applications, and details of constructing a system MTF budget for laser scanning systems that includes electronics, modulators, scanners, and optics.

  5. [Moving Mirror Scanning System Based on the Flexible Hinge Support].

    PubMed

    Xie, Fei; Feng, Fei; Wang, Fu-bei; Wu, Qiong-shui; Zeng, Li-bo

    2015-08-01

    In order to improve moving mirror drive of Fourier transform infrared spectrometer, we design a dynamic scanning system based on flexible hinge support. Using the flexible hinge support way and the voice coil motor drive mode. Specifically, Using right Angle with high accuracy high stability type flexible hinge support mechanism support moving mirror, dynamic mirror can be moved forward and backward driven by voice coil motor reciprocating motion, DSP control system to control the moving mirror at a constant speed. The experimental results show that the designed of moving mirror scanning system has advantages of stability direction, speed stability, superior seismic performance.

  6. Comparative Geometrical Investigations of Hand-Held Scanning Systems

    NASA Astrophysics Data System (ADS)

    Kersten, T. P.; Przybilla, H.-J.; Lindstaedt, M.; Tschirschwitz, F.; Misgaiski-Hass, M.

    2016-06-01

    An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google's Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

  7. Mathematical model for light scanning system based on circular laser

    NASA Astrophysics Data System (ADS)

    Xu, Peiquan; Yao, Shun; Lu, Fenggui; Tang, Xinhua; Zhang, Wei

    2005-11-01

    A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built. This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams, escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in "spot" or "line" type laser trajectory. Three-dimensional (3D) model for welded seams could be recognized after depth recovery. The imaging error is investigated also.

  8. A semi-automatic 3D laser scan system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Pan, Ming; Zhang, Xiangwei

    2009-11-01

    Digital 3D models are now used everywhere, from traditional fields of industrial design, artistic design, to heritage conservation. Although laser scan is very useful to get densely samples of the objects, nowadays, such an instrument is expensive and always need to be connected to a computer with stable power supply, which prevent it from usage for fieldworks. In this paper, a new semi-automatic 3D laser scan method is proposed using two line laser sources. The planes projected from the laser sources are orthogonal, one of which is fixed relative to the camera, and the other can be rotated along a settled axis. Before scanning, the system must be calibrated, from which the parameters of the camera, the position of the fixed laser plane and the settled axis are introduced. In scanning process, the fixed laser plane and the camera form a conventional structured light system, and the 3d positions of the intersection curves of the fixed laser plane with the object can be computed. The other laser plane is rotated manually or mechanically, and its position can be determined from the cross point intersecting with the fixed laser plane on the object, so the coordinates of sweeping points can be obtained. The new system can be used without a computer (The data can be processed later), which make it suitable for fieldworks. A scanning case is given in the end.

  9. Investigation of a scanned cylindrical ultrasound system for breast hyperthermia.

    PubMed

    Ju, Kuen-Cheng; Tseng, Li-Te; Chen, Yung-Yaw; Lin, Win-Li

    2006-02-07

    This paper investigates the feasibility of a scanned cylindrical ultrasound system for producing uniform heating from the central to the superficial portions of the breast or localized heating within the breast at a specific location. The proposed system consists of plane ultrasound transducer(s) mounted on a scanned cylindrical support. The breast was immersed in water and surrounded by this system during the treatment. The control parameters considered are the size of the transducer, the ultrasound frequency, the scan angle and the shifting distance between the axes of the breast and the system. Three-dimensional acoustical and thermal models were used to calculate the temperature distribution. Non-perfused phantom experiments were performed to verify the simulation results. Simulation results indicate that high frequency ultrasound could be used for the superficial heating, and the scan angle of the transducer could be varied to obtain an appropriate high temperature region to cover the desired treatment region. Low frequency ultrasound could be used for deep heating and the high temperature region could be moved by shifting the system. In addition, a combination of low and high frequency ultrasound could result in a portion treatment from the central to the superficial breast or an entire breast treatment. Good agreement was obtained between non-perfused experiments and simulation results. The findings of this study can be used to determine the effects of the control parameters of this system, as well as to select the optimal parameters for a specific treatment.

  10. Multispectral single-scan lung imaging system: initial feasibility

    NASA Astrophysics Data System (ADS)

    Besson, Guy M.; Crocker, Kenneth E.

    2006-03-01

    This paper describes a system for multi-spectral single-scan lung imaging. The proposed approach relies on a low noise detector sampled at a high rate. The proposed method overcomes limitations of CCD time-and-delay integration slot-scanning systems. The system design and preliminary specifications are described. The results of initial spectral and system simulations in support of system feasibility per the outlined specifications are described. Initial investigations support the potential of the proposed approach to alleviate four shortcomings of the current digital flat-panel approach to chest radiography: (i) by enabling dynamic multi-spectral imaging in a single scan, the approach reduces the time delay between exposures, thus reducing sensitivity to motion; (ii) the approach enables dynamic technique feedback and technique adaptation, eliminating the need for a pre-exposures and reducing the likelihood of poor x-ray techniques in local image areas; (iii) by enabling direct measurement of the scatter field, the proposed method allows further scatter correction resulting in image quality improvements; (iv) finally, full-frame sampling of a digital detector allows imaging of the beam penumbra, thereby reclaiming the detection quantum efficiency loss due to over-collimation in current TDI slot-scanning approach; the resulting DQE potentially exceeds that of flat-panel detectors by a factor up to two.

  11. Digital adaptive optics line-scanning confocal imaging system.

    PubMed

    Liu, Changgeng; Kim, Myung K

    2015-01-01

    A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea.

  12. Digital adaptive optics line-scanning confocal imaging system

    PubMed Central

    Liu, Changgeng; Kim, Myung K.

    2015-01-01

    Abstract. A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea. PMID:26140334

  13. Ultrahigh vacuum scanning electron microscope system combined with wide-movable scanning tunneling microscope

    SciTech Connect

    Kaneko, A.; Homma, Y.; Hibino, H.; Ogino, T.

    2005-08-15

    A surface analysis system has been newly developed with combination of ultrahigh vacuum scanning electron microscope (SEM) and wide-movable scanning tunneling microscope (STM). The basic performance is experimentally demonstrated. These SEM and STM images are clear enough to obtain details of surface structures. The STM unit moves horizontally over several millimeters by sliding motion of PZT actuators. The motion resolution is proved to be submicrometers. The STM tip mounted on another PZT scanner can be guided to a specific object on the sample surface during SEM observation. In the observation of a Si(111) surface rapidly cooled from high temperature, the STM tip was accurately guided to an isolated atomic step and slightly moved along it during SEM observation. The STM observation shows an asymmetry of the (7x7)-transformed region along the step between the upper and lower terraces. (7x7) bands continuously formed along the edge of terraces, while (7x7) domains distributed on the terraces slightly far from the step. These experiments show the wide-movable STM unit resolves a gap of observation area between SEM and STM and the system enables a specific object found in the SEM image to be observed easily by STM.

  14. A scanning defect mapping system for semiconductor characterization

    NASA Technical Reports Server (NTRS)

    Sopori, Bushnan L.

    1994-01-01

    We have developed an optical scanning system that generates maps of the spatial distributions of defects in single and polycrystalline silicon wafers. This instrument, called Scanning Defect Mapping System, utilizes differences in the scattering characteristics of dislocation etch pits and grain boundaries from a defect-etched sample to identify and count them. This system simultaneously operates in the dislocation mode and the grain boundary (GB) mode. In the 'dislocation mode,' the optical scattering from the etch pits is used to statistically count dislocations, while ignoring the GB's. Likewise, in the 'grain boundary mode' the system only recognizes the local scattering from the GB's to generate grain boundary distributions. The information generated by this instrument is valuable for material quality control, identifying mechanisms of defect generation and the nature of thermal stresses during the crystal growth, and the solar cell process design.

  15. Scan mirror remote temperature sensing system and method

    NASA Technical Reports Server (NTRS)

    VanDyk, Steven G. (Inventor); Balinski, Walter (Inventor); Choo, Ronald J. (Inventor); Bortfeldt, Paul E. (Inventor)

    2000-01-01

    A remote temperature sensing system (10) for a scanning mirror (7). The system (10) includes a sensor which detects heat radiated by the mirror and provides a signal in response thereto. In the illustrative implementation, the system (10) includes a thermistor mounted within a housing. The housing is contoured to maximize the receipt of thermal energy thereby. A mounting assembly maintains the thermistor a predetermined nonzero distance from the scanning mirror (7). The invention includes a shroud (12) mounted on the mirror (7) for shielding the thermistor and a support tube connected to the thermistor housing on a first end and to a base on the second end thereof. The support tube is adapted to remain stationary within the shroud as the scanning mirror and the shroud rotate due to the scanning of the mirror. Wires are connected to the thermistor on a first end thereof and are wrapped around the support tube. The wires include a length of electrically conductive material having a resistivity which has a low sensitivity to temperature variations. The sensor output is processed in a conventional manner to provide an output indicative of the temperature of the mirror.

  16. Dual-Frequency Airborne Scanning Rain Radar Antenna System

    NASA Technical Reports Server (NTRS)

    Hussein, Ziad A.; Green, Ken

    2004-01-01

    A compact, dual-frequency, dual-polarization, wide-angle-scanning antenna system has been developed as part of an airborne instrument for measuring rainfall. This system is an upgraded version of a prior single-frequency airborne rain radar antenna system and was designed to satisfy stringent requirements. One particularly stringent combination of requirements is to generate two dual-polarization (horizontal and vertical polarizations) beams at both frequencies (13.405 and 35.605 GHz) in such a way that the beams radiated from the antenna point in the same direction, have 3-dB angular widths that match within 25 percent, and have low sidelobe levels over a wide scan angle at each polarization-and-frequency combination. In addition, the system is required to exhibit low voltage standing-wave ratios at both frequencies. The system (see figure) includes a flat elliptical scanning reflector and a stationary offset paraboloidal reflector illuminated by a common-aperture feed system that comprises a corrugated horn with four input ports one port for each of the four frequency-and-polarization combinations. The feed horn is designed to simultaneously (1) under-illuminate the reflectors 35.605 GHz and (2) illuminate the reflectors with a 15-dB edge taper at 13.405 GHz. The scanning mirror is rotated in azimuth to scan the antenna beam over an angular range of 20 in the cross-track direction for wide swath coverage, and in elevation to compensate for the motion of the aircraft. The design of common-aperture feed horn makes it possible to obtain the required absolute gain and low side-lobe levels in wide-angle beam scanning. The combination of the common-aperture feed horn with the small (0.3) focal-length-to-diameter ratio of the paraboloidal reflector makes it possible for the overall system to be compact enough that it can be mounted on a DC-8 airplane.

  17. Ultrasonic scanning system for imaging flaw growth in composites

    NASA Technical Reports Server (NTRS)

    Kiraly, L. J.; Meyn, E. H.

    1982-01-01

    A system for measuring and visually representing damage in composite specimens while they are being loaded was demonstrated. It uses a hobbiest grade microcomputer system to control data taking and image processing. The system scans operator selected regions of the specimen while it is under load in a tensile test machine and measures internal damage by the attenuation of a 2.5 MHz ultrasonic beam passed through the specimen. The microcomputer dynamically controls the position of ultrasonic transducers mounted on a two axis motor driven carriage. As many as 65,536 samples can be taken and filed on a floppy disk system in less than four minutes.

  18. Dose error analysis for a scanned proton beam delivery system

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Wang, N.; Miller, D. W.; Yang, Y.

    2010-12-01

    All particle beam scanning systems are subject to dose delivery errors due to errors in position, energy and intensity of the delivered beam. In addition, finite scan speeds, beam spill non-uniformities, and delays in detector, detector electronics and magnet responses will all contribute errors in delivery. In this paper, we present dose errors for an 8 × 10 × 8 cm3 target of uniform water equivalent density with 8 cm spread out Bragg peak and a prescribed dose of 2 Gy. Lower doses are also analyzed and presented later in the paper. Beam energy errors and errors due to limitations of scanning system hardware have been included in the analysis. By using Gaussian shaped pencil beams derived from measurements in the research room of the James M Slater Proton Treatment and Research Center at Loma Linda, CA and executing treatment simulations multiple times, statistical dose errors have been calculated in each 2.5 mm cubic voxel in the target. These errors were calculated by delivering multiple treatments to the same volume and calculating the rms variation in delivered dose at each voxel in the target. The variations in dose were the result of random beam delivery errors such as proton energy, spot position and intensity fluctuations. The results show that with reasonable assumptions of random beam delivery errors, the spot scanning technique yielded an rms dose error in each voxel less than 2% or 3% of the 2 Gy prescribed dose. These calculated errors are within acceptable clinical limits for radiation therapy.

  19. High-definition laser display system using multibeam scanning

    NASA Astrophysics Data System (ADS)

    Zhao, Zhenming; Li, Yongda; Lang, Baihe

    2000-10-01

    The design and principles of a high definition laser display system with multi-beam scanning are described. The system employs 4 laser beams each being composed of red, green and blue components. The four beams from one scanner are scanned simultaneously by a rotating polygonal mirror for horizontal deflection and by a galvanometer for vertical deflection. Compared with conventional single-beam scanning, the new design has the following advantages: 1) The rotational speed of the polygonal mirrors can be reduced by a factor of 4, which would improve the system performance and decrease the difficulties of the manufacture of the system. The size of the polygonal facet and, therefore, the laser beam diameter can be increased which would decrease the pixel diffusion. 2) The simultaneous operation of the 4 modulators would improve the horizontal resolution by a factor of 4. 3) For the same screen brightness, the single pixel power density can be reduced by a factor of 4 which would decrease the hazardous laser radiation.

  20. A scanned beam THz imaging system for medical applications

    NASA Astrophysics Data System (ADS)

    Taylor, Zachary D.; Li, Wenzao; Suen, Jon; Tewari, Priyamvada; Bennett, David; Bajwa, Neha; Brown, Elliott; Culjat, Martin; Grundfest, Warren; Singh, Rahul

    2011-10-01

    THz medical imaging has been a topic of increased interest recently due largely to improvements in source and detector technology and the identification of suitable applications. One aspect of THz medical imaging research not often adequately addressed is pixel acquisition rate and phenomenology. The majority of active THz imaging systems use translation stages to raster scan a sample beneath a fixed THz beam. While these techniques have produced high resolution images of characterization targets and animal models they do not scale well to human imaging where clinicians are unwilling to place patients on large translation stages. This paper presents a scanned beam THz imaging system that can acquire a 1 cm2 area with 1 mm2 pixels and a per-pixel SNR of 40 dB in less than 5 seconds. The system translates a focused THz beam across a stationary target using a spinning polygonal mirror and HDPE objective lens. The illumination is centered at 525 GHz with ~ 125 GHz of response normalized bandwidth and the component layout is designed to optically co-locate the stationary source and detector ensuring normal incidence across a 50 mm × 50 mm field of view at standoff of 190 mm. Component characterization and images of a test target are presented. These results are some of the first ever reported for a short standoff, high resolution, scanned beam THz imaging system and represent an important step forward for practical integration of THz medical imaging where fast image acquisition times and stationary targets (patients) are requisite.

  1. Fast frame scanning camera system for light-sheet microscopy.

    PubMed

    Wu, Di; Zhou, Xing; Yao, Baoli; Li, Runze; Yang, Yanlong; Peng, Tong; Lei, Ming; Dan, Dan; Ye, Tong

    2015-10-10

    In the interest of improving the temporal resolution for light-sheet microscopy, we designed a fast frame scanning camera system that incorporated a galvanometer scanning mirror into the imaging path of a home-built light-sheet microscope. This system transformed a temporal image sequence to a spatial one so that multiple images could be acquired during one exposure period. The improvement factor of the frame rate was dependent on the number of sub-images that could be tiled on the sensor without overlapping each other and was therefore a trade-off with the image size. As a demonstration, we achieved 960 frames/s (fps) on a CCD camera that was originally capable of recording images at only 30 fps (full frame). This allowed us to observe millisecond or sub-millisecond events with ordinary CCD cameras.

  2. Raman mapping using advanced line-scanning systems: geological applications.

    PubMed

    Bernard, Sylvain; Beyssac, Olivier; Benzerara, Karim

    2008-11-01

    By allowing nondestructive chemical and structural imaging of heterogeneous samples with a micrometer spatial resolution, Raman mapping offers unique capabilities for assessing the spatial distribution of both mineral and organic phases within geological samples. Recently developed line-scanning Raman mapping techniques have made it possible to acquire Raman maps over large, millimeter-sized, zones of interest owing to a drastic decrease of the data acquisition time without losing spatial or spectral resolution. The synchronization of charge-coupled device (CCD) measurements with x,y motorized stage displacement has allowed dynamic line-scanning Raman mapping to be even more efficient: total acquisition time may be reduced by a factor higher than 100 compared to point-by-point mapping. Using two chemically and texturally complex geological samples, a fossil megaspore in a metamorphic rock and aragonite-garnet intergrowths in an Eclogitic marble, we compare here two recent versions of line-scanning Raman mapping systems and discuss their respective advantages and disadvantages in terms of acquisition time, image quality, spatial and imaging resolutions, and signal-to-noise ratio. We show that line-scanning Raman mapping techniques are particularly suitable for the characterization of such samples, which are representative of the general complexity of geological samples.

  3. Miniature image guided three-axis scanning and positioning system

    NASA Astrophysics Data System (ADS)

    Avirovik, Dragan; Dave, Digant; Priya, Shashank

    2012-04-01

    We have developed a high precision three axes scanning and positioning system for integration with Multifunctional Image Guided Surgical (MIGS) Platform. The stage integrates three main components: an optical coherence tomography (OCT) probe, laser scalpel and suction cup. The requirements for this stage were to provide scanning area of 400mm2, resolution of less than 10 microns and scanning velocity in the range of 10 - 40 mm/s. The stage was modeled using computer aided design software NX Unigraphics. In addition to the parameters mentioned above, additional boundary conditions for the stage were set as low volume and modularity. Optimized stage model was fabricated by using rapid prototyping technique that integrates low cost stepper motors, threaded rod drive train and a stepper motor controller. The EZ4axis stepper motor controller was able to provide 1/8th microstep resolution control over the motors, which met the criterion desired for the MIGS platform. Integration of computer controlled three-axis stage with MIGS platform provides the opportunity for conducting intricate surgical procedures using remote control or joystick. The device is image guided using the OCT probe and it is able to pin point any location requiring a laser scalpel incision. Due to the scanning capabilities, a high quality threedimensional image of the tissue topography is obtained which allows the surgeon to make a confident decision of where to apply the laser scalpel and make an incision.

  4. Logarithmic axicon characterized by scanning optical probe system.

    PubMed

    Cao, Zhaolou; Wang, Keyi; Wu, Qinglin

    2013-05-15

    A scanning optical probe system is proposed to measure a logarithmic axicon (LA) with subwavelength resolution. Multiple plane intensity profiles measured by a fiber probe are interpreted by solving an optimization problem to get the phase retardation function (PRF) of the LA. Experimental results show that this approach can accurately obtain the PRF with which the optical path difference of the generated quasi-nondiffracting beam in the propagation is calculated.

  5. PRF Ambiguity Detrmination for Radarsat ScanSAR System

    NASA Technical Reports Server (NTRS)

    Jin, Michael Y.

    1998-01-01

    PRF ambiguity is a potential problem for a spaceborne SAR operated at high frequencies. For a strip mode SAR, there were several approaches to solve this problem. This paper, however, addresses PRF ambiguity determination algorithms suitable for a burst mode SAR system such as the Radarsat ScanSAR. The candidate algorithms include the wavelength diversity algorithm, range look cross correlation algorithm, and multi-PRF algorithm.

  6. Superconducting Magnet System for a Low Temperature Laser Scanning Microscope

    DTIC Science & Technology

    2006-09-22

    Our initial studies with the LTLSM bought with this equipment grant show that the intragrain critical current density crosses over with the...SUBTITLE 5a. CONTRACT NUMBER Superconducting Magnet System for a Low Temperature Laser Scanning Microscope 5b. GRANT NUMBER FA9550-05-1-0425 5c...ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Applied Superconductivity Center 1500 Engineering Drive University of Wisconsin -Madison Room 909

  7. Land-Based Mobile Laser Scanning Systems: a Review

    NASA Astrophysics Data System (ADS)

    Puente, I.; González-Jorge, H.; Arias, P.; Armesto, J.

    2011-09-01

    Mobile mapping has been using various photogrammetric techniques for many years. In recent years, there has been an increase in the number of mobile mapping systems using laser scanners available in the market, partially because of the improvement in GNSS/INS performance for direct georeferencing. In this article, some of the most important land-based mobile laser scanning (MLS) systems are reviewed. Firstly, the main characteristics of MLS systems vs. airborne (ALS) and terrestrial laser scanning (TLS) systems are compared. Secondly, a short overview of the mobile mapping technology is also provided so that the reader can fully grasp the complexity and operation of these devices. As we put forward in this paper, a comparison of different systems is briefly carried out regarding specifications provided by the manufacturers. Focuses on the current research are also addressed with emphasis on the practical applications of these systems. Most of them have been utilized for data collection on road infrastructures or building façades. This article shows that MLS technology is nowadays well established and proven, since the demand has grown to the point that there are several systems suppliers offering their products to satisfy this particular market.

  8. Scanning laser system to determine the corneal shape

    NASA Astrophysics Data System (ADS)

    Ascanio, Gabriel; Caballero-Ruiz, Alberto; Ruiz-Huerta, Leopoldo; Gonzalez-Cardel, Mario; Diaz-Uribe, Rufino

    2005-07-01

    The development and tests of a scanning system to be used to determine the corneal topography with the laser deflectometry method are presented. In this equipment, a He-Ne laser beam scans the cornea by describing a spiral trajectory generated by two components: radial and angular. The first component is produced by the displacement of a plane mirror moved by a linear pneumatic actuator. The second component is produced by passing the beam through a Dove prism which is rotating by means of a belt drive coupled to a high-speed electric motor. Tests were first performed by analyzing both components independently and then they were characterized by combining the two components. Results are discussed and compared to those of an earlier cited work.

  9. Super-resolution for scanning light stimulation systems

    NASA Astrophysics Data System (ADS)

    Bitzer, L. A.; Neumann, K.; Benson, N.; Schmechel, R.

    2016-09-01

    Super-resolution (SR) is a technique used in digital image processing to overcome the resolution limitation of imaging systems. In this process, a single high resolution image is reconstructed from multiple low resolution images. SR is commonly used for CCD and CMOS (Complementary Metal-Oxide-Semiconductor) sensor images, as well as for medical applications, e.g., magnetic resonance imaging. Here, we demonstrate that super-resolution can be applied with scanning light stimulation (LS) systems, which are common to obtain space-resolved electro-optical parameters of a sample. For our purposes, the Projection Onto Convex Sets (POCS) was chosen and modified to suit the needs of LS systems. To demonstrate the SR adaption, an Optical Beam Induced Current (OBIC) LS system was used. The POCS algorithm was optimized by means of OBIC short circuit current measurements on a multicrystalline solar cell, resulting in a mean square error reduction of up to 61% and improved image quality.

  10. System Design Considerations In Bar-Code Laser Scanning

    NASA Astrophysics Data System (ADS)

    Barkan, Eric; Swartz, Jerome

    1984-08-01

    The unified transfer function approach to the design of laser barcode scanner signal acquisition hardware is considered. The treatment of seemingly disparate system areas such as the optical train, the scanning spot, the electrical filter circuits, the effects of noise, and printing errors is presented using linear systems theory. Such important issues as determination of depth of modulation, filter specification, tolerancing of optical components, and optimi-zation of system performance in the presence of noise are discussed. The concept of effective spot size to allow for impact of optical system and analog processing circuitry upon depth of modulation is introduced. Considerations are limited primarily to Gaussian spot profiles, but also apply to more general cases. Attention is paid to realistic bar-code symbol models and to implications with respect to printing tolerances.

  11. Minimum Detectable Activity for Tomographic Gamma Scanning System

    SciTech Connect

    Venkataraman, Ram; Smith, Susan; Kirkpatrick, J. M.; Croft, Stephen

    2015-01-01

    For any radiation measurement system, it is useful to explore and establish the detection limits and a minimum detectable activity (MDA) for the radionuclides of interest, even if the system is to be used at far higher values. The MDA serves as an important figure of merit, and often a system is optimized and configured so that it can meet the MDA requirements of a measurement campaign. The non-destructive assay (NDA) systems based on gamma ray analysis are no exception and well established conventions, such the Currie method, exist for estimating the detection limits and the MDA. However, the Tomographic Gamma Scanning (TGS) technique poses some challenges for the estimation of detection limits and MDAs. The TGS combines high resolution gamma ray spectrometry (HRGS) with low spatial resolution image reconstruction techniques. In non-imaging gamma ray based NDA techniques measured counts in a full energy peak can be used to estimate the activity of a radionuclide, independently of other counting trials. However, in the case of the TGS each “view” is a full spectral grab (each a counting trial), and each scan consists of 150 spectral grabs in the transmission and emission scans per vertical layer of the item. The set of views in a complete scan are then used to solve for the radionuclide activities on a voxel by voxel basis, over 16 layers of a 10x10 voxel grid. Thus, the raw count data are not independent trials any more, but rather constitute input to a matrix solution for the emission image values at the various locations inside the item volume used in the reconstruction. So, the validity of the methods used to estimate MDA for an imaging technique such as TGS warrant a close scrutiny, because the pair-counting concept of Currie is not directly applicable. One can also raise questions as to whether the TGS, along with other image reconstruction techniques which heavily intertwine data, is a suitable method if one expects to measure samples whose activities

  12. An optical scan-calibration system in scanning near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Yunliang; Zhang, Hao; Wang, Keyi

    2009-11-01

    Scanning Probe Microscopes(SPM) use piezoelectric actuators to generate the scans. But the nonlinearities inherent in the piezoelectric actuators limit the usefulness of the instruments in precision metrology. This paper describes a simple optical beam displacement sensor that is used to accurately measure the (x,y) position of a piezoelectric tube scanner used in Scanning Near-field Optical Microscope(SNOM). As the nonlinearities is too complex to make up a simple math model, this paper use the Artificial neural network to Calibrate the nonlinearities.

  13. CDX-U two-dimensional scanning microwave system

    NASA Astrophysics Data System (ADS)

    Forest, C. B.; Greene, G.; Ono, M.

    1990-10-01

    A versatile 2 mm scanning interferometer has been built for the CDX-U machine. The unique diagnostic access of CDX-U allows a vertical view through windows on the top and bottom, and a two-pass horizontal view through a side window which utilizes reflection off of a mirror mounted on the center column of the vessel. A single launching antenna and two separate receivers can be operated in a variety of modes including simple interferometry, polarimetry, and scattering. The optics, mechanical translation system, and 2 mm heterodyne receiver are described.

  14. /sup 67/Gallium lung scans in progressive systemic sclerosis

    SciTech Connect

    Baron, M.; Feiglin, D.; Hyland, R.; Urowitz, M.B.; Shiff, B.

    1983-08-01

    /sup 67/Gallium lung scans were performed in 19 patients with progressive systemic sclerosis (scleroderma). Results were expressed quantitatively as the /sup 67/Gallium Uptake Index. The mean total pulmonary /sup 67/Gallium Uptake Index in patients was significantly higher than that in controls (41 versus 25), and 4 patients (21%) fell outside the normal range. There were no clinical or laboratory variables that correlated with the /sup 56/Gallium uptake. Increased pulmonary /sup 67/Gallium uptake in scleroderma may prove useful as an index of pulmonary disease activity.

  15. Software requirements definition Shipping Cask Analysis System (SCANS)

    SciTech Connect

    Johnson, G.L.; Serbin, R.

    1985-07-21

    The US Nuclear Regulatory Commission (NRC) staff reviews the technical adequacy of applications for certification of designs of shipping casks for spent nuclear fuel. In order to confirm an acceptable design, the NRC staff may perform independent calculations. The current NRC procedure for confirming cask design analyses is laborious and tedious. Most of the work is currently done by hand or through the use of a remote computer network. The time required to certify a cask can be long. The review process may vary somewhat with the engineer doing the reviewing. Similarly, the documentation on the results of the review can also vary with the reviewer. To increase the efficiency of this certification process, LLNL was requested to design and write an integrated set of user-oriented, interactive computer programs for a personal microcomputer. The system is known as the NRC Shipping Cask Analysis System (SCANS). The computer codes and the software system supporting these codes are being developed and maintained for the NRC by LLNL. The objective of this system is generally to lessen the time and effort needed to review an application. Additionally, an objective of the system is to assure standardized methods and documentation of the confirmatory analyses used in the review of these cask designs. A software system should be designed based on NRC-defined requirements contained in a requirements document. The requirements document is a statement of a project's wants and needs as the users and implementers jointly understand them. The requirements document states the desired end products (i.e. WHAT's) of the project, not HOW the project provides them. This document describes the wants and needs for the SCANS system. 1 fig., 3 tabs.

  16. Image reconstruction and optimization using a terahertz scanned imaging system

    NASA Astrophysics Data System (ADS)

    Yıldırım, İhsan Ozan; Özkan, Vedat A.; Idikut, Fırat; Takan, Taylan; Şahin, Asaf B.; Altan, Hakan

    2014-10-01

    Due to the limited number of array detection architectures in the millimeter wave to terahertz region of the electromagnetic spectrum, imaging schemes with scan architectures are typically employed. In these configurations the interplay between the frequencies used to illuminate the scene and the optics used play an important role in the quality of the formed image. Using a multiplied Schottky-diode based terahertz transceiver operating at 340 GHz, in a stand-off detection scheme; the effect of image quality of a metal target was assessed based on the scanning speed of the galvanometer mirrors as well as the optical system that was constructed. Background effects such as leakage on the receiver were minimized by conditioning the signal at the output of the transceiver. Then, the image of the target was simulated based on known parameters of the optical system and the measured images were compared to the simulation. By using an image quality index based on χ2 algorithm the simulated and measured images were found to be in good agreement with a value of χ2 = 0 .14. The measurements as shown here will aid in the future development of larger stand-off imaging systems that work in the terahertz frequency range.

  17. Three-dimensional dental cast analyzing system using laser scanning.

    PubMed

    Kuroda, T; Motohashi, N; Tominaga, R; Iwata, K

    1996-10-01

    The purpose of this article is to introduce the outline of our newly developed three-dimensional dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a measuring device with a slit-ray laser projector and two sets of coupled charged devised video cameras, an image processing unit, a 16-bit personal computer as a controller, and an engineering workstation as a post processor. The dental cast is projected and scanned with a slit-ray laser beam. The raster coordinates of the target are determined with an image processor. Triangulation is applied to determine the location of each point. Generation of three-dimensional graphics of the dental cast takes approximately 40 minutes. About 90,000 sets of X, Y, Z coordinates are stored in the main memory of the microcomputer. The measurement error is less than 0.05 mm. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the palatal surface area and the volume of the oral cavity. The advantage of this system is that it facilitates the otherwise complicated and time-consuming mock surgery necessary for treatment planning in orthognathic surgery.

  18. The Mount Wilson solar magnetograph - Scanning and data system

    NASA Technical Reports Server (NTRS)

    Howard, R.

    1976-01-01

    The paper describes a computer-operated image-scanning and data-collection system for the magnetograph at the Mt. Wilson 150-foot Tower telescope. The system is based on a minicomputer with a 32K word core memory and a generalized interface unit for controlling image motion, a keyboard, and an associated television screen. Operation of the solar image guider and the data-collection assembly is outlined along with the observation and data-reduction procedures. Advantages of the system include the ability to move the image in almost any conceivable fashion, a wide choice of integration times, and increased accuracy in magnetic and Doppler calibrations as well as in setting of the magnetic zero level.

  19. Sample heating system for spin-polarized scanning electron microscopy.

    PubMed

    Kohashi, Teruo; Motai, Kumi

    2013-08-01

    A sample-heating system for spin-polarized scanning electron microscopy (spin SEM) has been developed and used for microscopic magnetization analysis at temperatures up to 500°C. In this system, a compact ceramic heater and a preheating operation keep the ultra-high vacuum conditions while the sample is heated during spin SEM measurement. Moreover, the secondary-electron collector, which is arranged close to the sample, was modified so that it is not damaged at high temperatures. The system was used to heat a Co(1000) single-crystal sample from room temperature up to 500°C, and the magnetic-domain structures were observed. Changes of the domain structures were observed around 220 and 400°C, and these changes are considered to be due to phase transitions of this sample.

  20. Optoelectronic scanning system upgrade by energy center localization methods

    NASA Astrophysics Data System (ADS)

    Flores-Fuentes, W.; Sergiyenko, O.; Rodriguez-Quiñonez, J. C.; Rivas-López, M.; Hernández-Balbuena, D.; Básaca-Preciado, L. C.; Lindner, L.; González-Navarro, F. F.

    2016-11-01

    A problem of upgrading an optoelectronic scanning system with digital post-processing of the signal based on adequate methods of energy center localization is considered. An improved dynamic triangulation analysis technique is proposed by an example of industrial infrastructure damage detection. A modification of our previously published method aimed at searching for the energy center of an optoelectronic signal is described. Application of the artificial intelligence algorithm of compensation for the error of determining the angular coordinate in calculating the spatial coordinate through dynamic triangulation is demonstrated. Five energy center localization methods are developed and tested to select the best method. After implementation of these methods, digital compensation for the measurement error, and statistical data analysis, a non-parametric behavior of the data is identified. The Wilcoxon signed rank test is applied to improve the result further. For optical scanning systems, it is necessary to detect a light emitter mounted on the infrastructure being investigated to calculate its spatial coordinate by the energy center localization method.

  1. PSIDD (2): A Prototype Post-Scan Interactive Data Display System for Detailed Analysis of Ultrasonic Scans

    NASA Technical Reports Server (NTRS)

    Cao, Wei; Roth, Don J.

    1997-01-01

    This article presents the description of PSIDD(2), a post-scan interactive data display system for ultrasonic contact scan and single measurement analysis. PSIDD(2) was developed in conjunction with ASTM standards for ultrasonic velocity and attenuation coefficient contact measurements. This system has been upgraded from its original version PSIDD(1) and improvements are described in this article. PSIDD(2) implements a comparison mode where the display of time domain waveforms and ultrasonic properties versus frequency can be shown for up to five scan points on one plot. This allows the rapid contrasting of sample areas exhibiting different ultrasonic properties as initially indicated by the ultrasonic contact scan image. This improvement plus additional features to be described in the article greatly facilitate material microstructural appraisal.

  2. Hyperspectral imaging system for disease scanning on banana plants

    NASA Astrophysics Data System (ADS)

    Ochoa, Daniel; Cevallos, Juan; Vargas, German; Criollo, Ronald; Romero, Dennis; Castro, Rodrigo; Bayona, Oswaldo

    2016-05-01

    Black Sigatoka (BS) is a banana plant disease caused by the fungus Mycosphaerella fijiensis. BS symptoms can be observed at late infection stages. By that time, BS has probably spread to other plants. In this paper, we present our current work on building an hyper-spectral (HS) imaging system aimed at in-vivo detection of BS pre-symptomatic responses in banana leaves. The proposed imaging system comprises a motorized stage, a high-sensitivity VIS-NIR camera and an optical spectrograph. To capture images of the banana leaf, the stage's speed and camera's frame rate must be computed to reduce motion blur and to obtain the same resolution along both spatial dimensions of the resulting HS cube. Our continuous leaf scanning approach allows imaging leaves of arbitrary length with minimum frame loss. Once the images are captured, a denoising step is performed to improve HS image quality and spectral profile extraction.

  3. Cooperative Environment Scans Based on a Multi-Robot System

    PubMed Central

    Kwon, Ji-Wook

    2015-01-01

    This paper proposes a cooperative environment scan system (CESS) using multiple robots, where each robot has low-cost range finders and low processing power. To organize and maintain the CESS, a base robot monitors the positions of the child robots, controls them, and builds a map of the unknown environment, while the child robots with low performance range finders provide obstacle information. Even though each child robot provides approximated and limited information of the obstacles, CESS replaces the single LRF, which has a high cost, because much of the information is acquired and accumulated by a number of the child robots. Moreover, the proposed CESS extends the measurement boundaries and detects obstacles hidden behind others. To show the performance of the proposed system and compare this with the numerical models of the commercialized 2D and 3D laser scanners, simulation results are included. PMID:25789491

  4. Calibration technology in application of robot-laser scanning system

    NASA Astrophysics Data System (ADS)

    Ren, YongJie; Yin, ShiBin; Zhu, JiGui

    2012-11-01

    A system composed of laser sensor and 6-DOF industrial robot is proposed to obtain complete three-dimensional (3-D) information of the object surface. Suitable for the different combining ways of laser sensor and robot, a new method to calibrate the position and pose between sensor and robot is presented. By using a standard sphere with known radius as a reference tool, the rotation and translation matrices between the laser sensor and robot are computed, respectively in two steps, so that many unstable factors introduced in conventional optimization methods can be avoided. The experimental results show that the accuracy of the proposed calibration method can be achieved up to 0.062 mm. The calibration method is also implemented into the automated robot scanning system to reconstruct a car door panel.

  5. Numerical Modeling of a Near-Field Scanning Optical System

    NASA Astrophysics Data System (ADS)

    Kann, Joshua Louis

    A near-field scanning optical (NFO) system utilizes a subwavelength sized aperture to illuminate a sample. The aperture raster scans the sample. During the scan, the aperture is held in proximity to the sample. At each sampling point, the integrated far-zone energy distribution is stored. This collection of data is used to generate an image of the sample's surface. The main advantage of NFO systems is their very high spatial resolution. In this dissertation a hybrid finite-difference-time-domain (FDTD)/angular spectrum code is used to study the electromagnetic and imaging properties of a NFO scanning system. In addition, a finite-difference thermal (FD-thermal) code is used to calculate the thermal properties of a NFO system. Various aperture/sample geometries are studied numerically using both TE and TM polarization within a two-dimensional metallic waveguide that forms the aperture. The spatial properties of the electric field emitted by the aperture with no sample present are greatly influenced by the polarization. In particular, the electric field with TM polarization exhibits sharp peaks near the corners of the aperture, while the field with TE polarization is smooth and peaked at the center of the aperture. For both polarizations, the electric field remains collimated for a distance comparable to the aperture size. The electric field for both polarizations is altered when a dielectric sample is placed in proximity to the aperture. It is shown that the most representative image of the sample's topography is obtained using TE polarization and the resulting total far-zone energy as the sampled data. It is also shown that simpler scalar methods do not accurately predict the imaging behavior of a NFO system. Under certain circumstances the relationship between the sample's topography and the detected image is nearly linear. Under these conditions a system transfer function is calculated. Using the transfer function, it is shown that the spatial resolution of a NFO

  6. High-sensitive scanning laser magneto-optical imaging system.

    PubMed

    Murakami, Hironaru; Tonouchi, Masayoshi

    2010-01-01

    A high-sensitive scanning laser magneto-optical (MO) imaging system has been developed. The system is mainly composed of a laser source, galvano meters, and a high-sensitive differential optical-detector. Preliminary evaluation of system performance by using a Faraday indicator with a Faraday rotation coefficient of 3.47 x 10(-5) rad/microm Oe shows a magnetic sensitivity of about 5 microT, without any need for accumulation or averaging processing. Using the developed MO system we have succeeded in the fast and quantitative imaging of a rotationally symmetric magnetic field distribution around an YBa(2)Cu(3)O(7-delta) (YBCO) strip line applied with dc-biased current, and also succeeded in the detection of quantized fine signals corresponding to magnetic flux quantum generation in a superconducting loop of an YBCO Josephson vortex flow transistor. Thus, the developed system enables us not only to do fast imaging and local signal detection but also to directly evaluate both the strength and direction of a magnetic signal.

  7. Galvanometer beam-scanning system for laser fiber drawing.

    PubMed

    Oehrle, R C

    1979-02-15

    A major difficulty in using a laser to draw optical fibers from a glass preform has been uniformally distributing the laser's energy around the melt zone. Several systems have evolved in recent years, but to date the most successful technique has been the off-axis rotating lens system (RLS). The inability of this device to structure efficiently and dynamically the heat zone longitudinally along the preform has restricted its use to preform of less than 8-mm diameter. A new technique reported here employs two orthogonal mounted mirrors, driven by galvanometers to distribute the laser energy around the preform. This system can be retrofitted into the RLS to replace the rotating lens element. The new system, the galvanometer scanning system (GSS), operates at ten times the rotational speed of the RLS and can instantaneously modify the melt zone. The ability of the GSS to enlarge the melt zone reduces the vaporization rate at the surface of the preform permitting efficient use of higher laser power. Experiments i dicate that fibers can be drawn from significantly larger preforms by using the expanded heat zone provided by the GSS.

  8. Mechatronic Scanning System with Integrated Micro Electro Mechanical System Position Sensors

    NASA Astrophysics Data System (ADS)

    Stavrov, Vladimir; Chakarov, Dimitar; Shulev, Assen; Tsveov, Mihail

    2016-06-01

    In this paper, a study of a mechatronic scanning system for application in the microbiology, microelectronics research, chemistry, etc. is presented. Integrated silicon micro electro mechanical system (MEMS) position sensor is used for monitoring the displacement of the scanning system. The utilized silicon MEMS sensors with sidewall embedded piezoresistors possess a number of key advantages such as high sensitivity, low noise and extremely low temperature dependence. Design of 2D scanning system with a travel range of 22 × 22 μm2 has been presented in present work. This system includes a Compliant Transmission Mechanism, (CTM) designed as a complex elastic mechanism, comprising four parallelograms. Computer aided desigh (CAD) model and finite element analysis (FEA) of the Compliant Transmission Mechanism mechanisms have been carried out. A prototype of the scanning system is fabricated, based on CAD model. An experimental set-up of an optical system and a correlation technique for digital image processing have been used for testing the scanning system prototype. Results of the experimental investigations of the prototyped scanning system are also presented.

  9. Scanned Image Projection System Employing Intermediate Image Plane

    NASA Technical Reports Server (NTRS)

    DeJong, Christian Dean (Inventor); Hudman, Joshua M. (Inventor)

    2014-01-01

    In imaging system, a spatial light modulator is configured to produce images by scanning a plurality light beams. A first optical element is configured to cause the plurality of light beams to converge along an optical path defined between the first optical element and the spatial light modulator. A second optical element is disposed between the spatial light modulator and a waveguide. The first optical element and the spatial light modulator are arranged such that an image plane is created between the spatial light modulator and the second optical element. The second optical element is configured to collect the diverging light from the image plane and collimate it. The second optical element then delivers the collimated light to a pupil at an input of the waveguide.

  10. A Mobile Automated Tomographic Gamma Scanning System - 13231

    SciTech Connect

    Kirkpatrick, J.M.; LeBlanc, P.J.; Nakazawa, D.; Petroka, D.L.; Kane Smith, S.; Venkataraman, R.; Villani, M.

    2013-07-01

    Canberra Industries have recently designed and built a new automated Tomographic Gamma Scanning (TGS) system for mobile deployment. The TGS technique combines high-resolution gamma spectroscopy with low spatial resolution 3-dimensional image reconstruction to provide increased accuracy over traditional approaches for the assay of non-uniform source distributions in low-to medium-density, non-heterogeneous matrices. Originally pioneered by R. Estep at Los Alamos National Laboratory (LANL), the TGS method has been further developed and commercialized by Canberra Industries in recent years. The present system advances the state of the art on several fronts: it is designed to be housed in a standard cargo transport container for ease of transport, allowing waste characterization at multiple facilities under the purview of a single operator. Conveyor feed, drum rotator, and detector and collimator positioning mechanisms operated by programmable logic control (PLC) allow automated batch mode operation. The variable geometry settings can accommodate a wide range of waste packaging, including but not limited to standard 220 liter drums, 380 liter overpack drums, and smaller 20 liter cans. A 20 mCi Eu-152 transmission source provides attenuation corrections for drum matrices up to 1 g/cm{sup 3} in TGS mode; the system can be operated in Segmented Gamma Scanning (SGS) mode to measure higher density drums. To support TGS assays at higher densities, the source shield is sufficient to house an alternate Co-60 transmission source of higher activity, up to 250 mCi. An automated shutter and attenuator assembly is provided for operating the system with a dual intensity transmission source. The system's 1500 kg capacity rotator turntable can handle heavy containers such as concrete lined 380 liter overpack drums. Finally, data acquisition utilizes Canberra's Broad Energy Germanium (BEGE) detector and Lynx MCA, with 32 k channels, providing better than 0.1 keV/channel resolution to

  11. Laser Scanning System for Pressure and Temperature Paints

    NASA Technical Reports Server (NTRS)

    Sullivan, John

    1997-01-01

    Acquiring pressure maps of aerodynamic surfaces is very important for improving and validating the performance of aerospace vehicles. Traditional pressure measurements are taken with pressure taps embedded in the model surface that are connected to transducers. While pressure taps allow highly accurate measurements to be acquired, they do have several drawbacks. Pressure taps do not give good spatial resolution due to the need for individual pressure tubes, compounded by limited space available inside models. Also, building a model proves very costly if taps are needed because of the large amount of labor necessary to drill, connect and test each one. The typical cost to install one tap is about $200. Recently, a new method for measuring pressure on aerodynamic surfaces has been developed utilizing a technology known as pressure sensitive paints (PSP). Using PSP, pressure distributions can be acquired optically with high spatial resolution and simple model preparation. Flow structures can be easily visualized using PSP, but are missed using low spatial resolution arrays of pressure taps. PSP even allows pressure distributions to be found on rotating machinery where previously this has been extremely difficult or even impossible. The goal of this research is to develop a laser scanning system for use with pressure sensitive paints that allows accurate pressure measurements to be obtained on various aerodynamic surfaces ranging from wind tunnel models to high speed jet engine compressor blades.

  12. A novel scanning system using an industrial robot and the workspace measurement and positioning system

    NASA Astrophysics Data System (ADS)

    Zhao, Ziyue; Zhu, Jigui; Yang, Linghui; Lin, Jiarui

    2015-10-01

    The present scanning system consists of an industrial robot and a line-structured laser sensor which uses the industrial robot as a position instrument to guarantee the accuracy. However, the absolute accuracy of an industrial robot is relatively poor compared with the good repeatability in the manufacturing industry. This paper proposes a novel method using the workspace measurement and positioning system (wMPS) to remedy the lack of accuracy of the industrial robot. In order to guarantee the positioning accuracy of the system, the wMPS which is a laser-based measurement technology designed for large-volume metrology applications is brought in. Benefitting from the wMPS, this system can measure different cell-areas by the line-structured laser sensor and fuse the measurement data of different cell-areas by using the wMPS accurately. The system calibration which is the procedure to acquire and optimize the structure parameters of the scanning system is also stated in detail in this paper. In order to verify the feasibility of the system for scanning the large free-form surface, an experiment is designed to scan the internal surface of the door of a car-body in white. The final results show that the measurement data of the whole measuring areas have been jointed perfectly and there is no mismatch in the figure especially in the hole measuring areas. This experiment has verified the rationality of the system scheme, the correctness and effectiveness of the relevant methods.

  13. A 3-d laser scanning system and scan data processing method for the monitoring of tunnel deformations

    NASA Astrophysics Data System (ADS)

    Chmelina, Klaus; Jansa, Josef; Hesina, Gerd; Traxler, Christoph

    2012-11-01

    The paper presents the mobile multi-sensor system Orthos Plus for the monitoring and mapping of tunnel walls, a scan data processing method for the evaluation of 3-d tunnel wall displacements from subsequent wall scans and, finally, a virtual reality tool supporting the interpretation of data. The measuring system consists of a 3-d laser scanner, a motorised total station and a digital camera that are integrated on a light metal frame that is installed on a mobile platform. It has been designed to perform tunnel measurements most efficiently and to meet the special requirements of tunnels under construction. The evaluation of 3-d displacements is based on a 3-d matching algorithm that takes advantage of the particular conditions of tunnel (shotcrete) surfaces. The virtual reality tool allows viewing of data in a 3-d virtual reality tunnel model and their animation in time and space in order supports understanding in an optimal way. The measuring system Orthos Plus has been developed in the course of a national research project, the 3-d matching method in the frame of the Austrian Christian Doppler Laboratory Spatial Data from Laser Scanning and Remote Sensing and the VR tool in the Austrian COMET K1 Competence Center VRVis Center (www.vrvis.at).

  14. Miniaturized hand held microwave interference scanning system for NDE of dielectric armor and armor systems

    SciTech Connect

    Schmidt, Karl F.; Little, Jack R.; Ellingson, William A.; Meitzler, Thomas J.; Green, William

    2011-06-23

    Inspection of ceramic-based armor has advanced through development of a microwave-based, portable, non-contact NDE system. Recently, this system was miniaturized and made wireless for maximum utility in field applications. The electronic components and functionality of the laboratory system are retained, with alternative means of position input for creation of scan images. Validation of the detection capability was recently demonstrated using specially fabricated surrogates and ballistic impact-damaged specimens. The microwave data results have been compared to data from laboratory-based microwave interferometry systems and digital x-ray imaging. The microwave interference scanning has been shown to reliably detect cracks, laminar features and material property variations. The authors present details of the system operation, descriptions of the test samples used and recent results obtained.

  15. Developing Environmental Scanning/Forecasting Systems To Augment Community College Planning.

    ERIC Educational Resources Information Center

    Morrison, James L.; Held, William G.

    A description is provided of a conference session that was conducted to explore the structure and function of an environmental scanning/forecasting system that could be used in a community college to facilitate planning. Introductory comments argue that a college that establishes an environmental scanning and forecasting system is able to identify…

  16. Millimeter Wave Synthetic Aperture Imaging System with a Unique Rotary Scanning System

    NASA Technical Reports Server (NTRS)

    Ghasr, M. T.; Pommerenke, D.; Case, J. T.; McClanahan, A. D.; Afaki-Beni, A.; Abou-Khousa, M.; Guinn, K.; DePaulis, F.; Kharkovsky, S.; Zoughi, R.

    2008-01-01

    In recent years, millimeter wave imaging techniques, using synthetic aperture focusing and holographical approaches, have shown tremendous potential for nondestructive testing applications, involving materials and structures used in space vehicles, including the space shuttle external fuel tank spray on foam insulation and its acreage heat tiles. The ability of signals at millimeter wave frequencies (30 - 300 GHz) to easily penetrate inside of low loss dielectric materials, their relatively small wavelengths, and the possibility of detecting coherent (magnitude and phase) reflections make them suitable for high resolution synthetic aperture focused imaging the interior of such materials and structures. To accommodate imaging requirements, commonly a scanning system is employed that provides for a raster scan of the desired structure. However, most such scanners, although simple in design and construction, are inherently slow primarily due to the need to stop and start at the beginning and end of each scan line. To this end, a millimeter wave synthetic aperture focusing system including a custom-designed transceiver operating at 35 - 45 GHz (Q-band) and unique and complex rotary scanner was designed and developed. The rotary scanner is capable of scanning an area with approximately 80 cm in diameter in less than 10 minutes at step sizes of 3 mm and smaller. The transceiver is capable of producing accurate magnitude and phase of reflected signal from the structure under test. Finally, a synthetic aperture focusing algorithm was developed that translates this rotary-obtained magnitude and phase into a synthetic aperture focusing image of inspected structures. This paper presents the design of the transceiver and the rotary scanning system along with showing several images obtained with this system from various complicated structures.

  17. Angle extended linear MEMS scanning system for 3D laser vision sensor

    NASA Astrophysics Data System (ADS)

    Pang, Yajun; Zhang, Yinxin; Yang, Huaidong; Zhu, Pan; Gai, Ye; Zhao, Jian; Huang, Zhanhua

    2016-09-01

    Scanning system is often considered as the most important part for 3D laser vision sensor. In this paper, we propose a method for the optical system design of angle extended linear MEMS scanning system, which has features of huge scanning degree, small beam divergence angle and small spot size for 3D laser vision sensor. The principle of design and theoretical formulas are derived strictly. With the help of software ZEMAX, a linear scanning optical system based on MEMS has been designed. Results show that the designed system can extend scanning angle from ±8° to ±26.5° with a divergence angle small than 3.5 mr, and the spot size is reduced for 4.545 times.

  18. Determining the flare dispensing program effectiveness against conical-scan and spin-scan reticle systems via Gaussian mixture models

    NASA Astrophysics Data System (ADS)

    Şahingil, Mehmet C.; Aslan, Murat Ş.

    2013-05-01

    The reticle systems which are considered as the classical approach for determining the angular position of radiating targets in infrared band are widely used in early generation surface-to-air and air-to-air infrared guided missile seekers. One of the cost-effective ways of protecting aircrafts against these missiles is to dispense flare decoys from the countermeasure dispensing system (CMDS) integrated into the aircraft platform. Although this counter-measuring technique seems very simple, if not optimized carefully, it may not be effective for protecting the aircraft. Flares should be dispensed in accordance with a specific dispensing program which determines the number of flares to be dispensed from each dispenser of the CMDS and timing sequence of dispensing. Optimizing the parameters of the dispensing program is not trivial. It requires a good understanding of the operating principle of the threat seeker, operational capabilities of own platform and engagement scenario between them. In the present paper, we propose a complete simulation-based procedure to form an effectiveness boundary of flare dispensing programs against the spin-scan and conical-scan reticle seekers. The region of effectiveness is determined via Gaussian mixture models. The raw data is collected via extensive number of simulations using a MATLAB-coded simulator which models reticle-based seeker, aircraft radiation, aircraft motion, aircraft CMDS system, flare motion and flare radiation.

  19. Reducing field distortion for galvanometer scanning system using a vision system

    NASA Astrophysics Data System (ADS)

    Ortega Delgado, Moises Alberto; Lasagni, Andrés Fabián

    2016-11-01

    Laser galvanometer scanning systems are well-established devices for material processing, medical imaging and laser projection. Besides all the advantages of these devices like high resolution, repeatability and processing velocity, they are always affected by field distortions. Different pre-compensating techniques using iterative marking and measuring methods are applied in order to reduce such field distortions and increase in some extends the accuracy of the scanning systems. High-tech devices, temperature control systems and self-adjusting galvanometers are some expensive possibilities for reducing these deviations. This contribution presents a method for reducing field distortions using a coaxially coupled vision device and a self-designed calibration plate; this avoids, among others, the necessity of repetitive marking and measuring phases.

  20. Adaptive noise Wiener filter for scanning electron microscope imaging system.

    PubMed

    Sim, K S; Teh, V; Nia, M E

    2016-01-01

    Noise on scanning electron microscope (SEM) images is studied. Gaussian noise is the most common type of noise in SEM image. We developed a new noise reduction filter based on the Wiener filter. We compared the performance of this new filter namely adaptive noise Wiener (ANW) filter, with four common existing filters as well as average filter, median filter, Gaussian smoothing filter and the Wiener filter. Based on the experiments results the proposed new filter has better performance on different noise variance comparing to the other existing noise removal filters in the experiments.

  1. Ultrasonic scanning system for in-place inspection of brazed tube joints

    NASA Technical Reports Server (NTRS)

    Haynes, J. L.; Wages, C. G.; Haralson, H. S. (Inventor)

    1973-01-01

    A miniaturized ultrasonic scanning system for nondestructive in-place, non-immersion testing of brazed joints in stainless-steel tubing is described. The system is capable of scanning brazed tube joints, with limited clearance access, in 1/4 through 5/8 inch union, tee, elbow and cross configurations. The system has the capability to detect defective conditions now associated with material density changes in addition to those which are depended upon density variations. The system includes a miniaturized scanning head assembly that fits around a tube joint and rotates the transducer around and down the joint in a continuous spiral motion. The C-scan recorder is similar in principle to conventional models except that it was specially designed to track the continuous spiral scan of the tube joint. The scanner and recorder can be operated with most commercially available ultrasonic flaw detectors.

  2. Control electronics for a multi-laser/multi-detector scanning system

    NASA Technical Reports Server (NTRS)

    Kennedy, W.

    1980-01-01

    The Mars Rover Laser Scanning system uses a precision laser pointing mechanism, a photodetector array, and the concept of triangulation to perform three dimensional scene analysis. The system is used for real time terrain sensing and vision. The Multi-Laser/Multi-Detector laser scanning system is controlled by a digital device called the ML/MD controller. A next generation laser scanning system, based on the Level 2 controller, is microprocessor based. The new controller capabilities far exceed those of the ML/MD device. The first draft circuit details and general software structure are presented.

  3. Microcomputer-based image processing system for CT/MRI scans: II. Expert system

    NASA Astrophysics Data System (ADS)

    Kwok, John C. K.; Yu, Peter K. N.; Cheng, Andrew Y. S.; Ho, Wai-Chin

    1991-06-01

    A microcomputer-based image processing system is used to digitize and process serial sections of CT/MRI scan and reconstruct three-dimensional images of brain structures and brain lesions. The images grabbed also serve as templates and different vital regions with different risk values are also traced out for 3D reconstruction. A knowledge-based system employing rule-based programming has been built to help identifying brain lesions and to help planning trajectory for operations. The volumes of the lesions are also automatically determined. Such system is very useful for medical skills archival, tumor size monitoring, survival and outcome forecasting, and consistent neurosurgical planning.

  4. Design of a fast electron beam scanning system for compact synchrotron light sources

    NASA Astrophysics Data System (ADS)

    Moser, H. O.; Lehr, H.

    1989-07-01

    The design of an electron beam scanning system for compact storage ring synchrotron light sources is described. The main features are a scan frequency of 100 Hz and an angular amplitude of ±5 mrad. Different configurations of scan dipoles permit confining the scan to one cell using four dipoles or to repeat the scan periodically along the whole circumference by means of two scan dipoles per cell. Combinations of these basic configurations are possible. The location of the nodes of the pivoting electron beam can be optimized with respect to the maximum scan angle by slightly unbalancing the field strength in different scan dipoles. The scan dipoles are H-shaped magnets made from laminated iron. Their gap width is 68 mm. They are powered by fast transistor-bridge supplies which are controlled by freely programmable function generators capable of realizing a triangular current waveform with a deviation of less than 0.1% except for a 1% neighborhood of the apex. Estimates of the influence of the scanning on both quantum and Coulomb lifetime indicate acceptable lifetime reductions provided the minimum distance between distorted closed orbit and aperture exceeds about six standard deviations of the spatial electron distribution.

  5. A line-scan hyperspectral system for high-throughput Raman chemical imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A line-scan hyperspectral system was developed to enable Raman chemical imaging for large sample areas. A custom-designed 785 nm line-laser, based on a scanning mirror, serves as an excitation source. A 45° dichroic beamsplitter reflects the laser light to form a 24 cm × 1 mm excitation line normall...

  6. A cryogenic Quadraprobe scanning tunneling microscope system with fabrication capability for nanotransport research.

    PubMed

    Kim, Tae-Hwan; Wang, Zhouhang; Wendelken, John F; Weitering, Hanno H; Li, Wenzhi; Li, An-Ping

    2007-12-01

    We describe the development and the capabilities of an advanced system for nanoscale electrical transport studies. This system consists of a low temperature four-probe scanning tunneling microscope (STM) and a high-resolution scanning electron microscope coupled to a molecular-beam epitaxy sample preparation chamber. The four STM probes can be manipulated independently with subnanometer precision, enabling atomic resolution STM imaging and four-point electrical transport study of surface electronic systems and nanostructured materials at temperatures down to 10 K. Additionally, an integrated energy analyzer allows for scanning Auger microscopy to probe chemical species of nanostructures. Some testing results are presented.

  7. Search and tracking system architecture using 1-D scanning sensors

    NASA Astrophysics Data System (ADS)

    Nam, Sanghoon; Choi, Byungin; Joung, Shichang; Kim, Jaein

    2010-04-01

    In the maritime environment, It is necessary for ship's self protection to search ad track approaching targets. We developed high performance search and tracking system with Infrared sensors. Our system can obtain high performance with several FPGAs and COTS processing boards. Dual band IR sensor (MWIR and LWIR) also gives two types of target detection and tracing abilities. Our system designed to automatically detect and track both air and surface targets such as sea skimming missiles, small ships, and aircrafts at a long range. In this paper, we describe technologies in our search and tracking system architecture. We describe software architecture for signal processing and target detection and tracking algorithms as well.

  8. Microstructural and Defect Characterization in Ceramic Composites Using an Ultrasonic Guided Wave Scan System

    NASA Technical Reports Server (NTRS)

    Roth, D. J.; Cosgriff, L. M.; Martin, R. E.; Verrilli, M. J.; Bhatt, R. T.

    2003-01-01

    In this study, an ultrasonic guided wave scan system was used to characterize various microstructural and flaw conditions in two types of ceramic matrix composites, SiC/SiC and C/SiC. Rather than attempting to isolate specific lamb wave modes to use for characterization (as is desired for many types of guided wave inspection problems), the guided wave scan system utilizes the total (multi-mode) ultrasonic response in its inspection analysis. Several time and frequency-domain parameters are calculated from the ultrasonic guided wave signal at each scan location to form images. Microstructural and defect conditions examined include delamination, density variation, cracking, and pre/ post-infiltration. Results are compared with thermographic imaging methods. Although the guided wave technique is commonly used so scanning can be eliminated, applying the technique in the scanning mode allows a more precise characterization of defect conditions.

  9. Use of serial bone scans in assessing response of bone metastases to systemic treatment

    SciTech Connect

    Citrin, D.L.; Hougen, C.; Zweibel, W.; Schlise, S.; Pruitt, B.; Ershler, W.; Davis, T.E.; Harberg, J.; Cohen, A.I.

    1981-02-15

    The accuracy levels of serial radioisotope bone scans and conventional bone radiographs in assessing the response of bone metastases to systemic therapy were compared in 34 women with metastatic breast cancer. Each patient had measurable or evaluable nonosseous metastases, which were assessed independently of skeletal disease. The bone scan was found to be more accurate and sensitive indicator of the status of bone metastases than the radiograph. The bone scan correlated well with response of soft tissue or visceral disease, while the results of repeated bone radiographs were frequently misleading. With use of a digital model, it was possible to accurately measure the area of skeletal involvement of the bone scan, and from this derive quantitative criteria for response in bone metastases analogous to response criteria currently in use for soft tissue and visceral disease. It is suggested that serial quantitative bone scans be done, in preference to radiographs, to assess the response of bone metastases to systemic therapy.

  10. Two-axis polydimethylsiloxane-based electromagnetic microelectromechanical system scanning mirror for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Kim, Sehui; Lee, Changho; Kim, Jin Young; Kim, Jeehyun; Lim, Geunbae; Kim, Chulhong

    2016-10-01

    Compact size and fast imaging abilities are key requirements for the clinical implementation of an optical coherence tomography (OCT) system. Among the various small-sized technology, a microelectromechanical system (MEMS) scanning mirror is widely used in a miniaturized OCT system. However, the complexities of conventional MEMS fabrication processes and relatively high costs have restricted fast clinical translation and commercialization of the OCT systems. To resolve these problems, we developed a two-axis polydimethylsiloxane (PDMS)-based MEMS (2A-PDMS-MEMS) scanning mirror through simple processes with low costs. It had a small size of 15×15×15 mm3, was fast, and had a wide scanning range at a low voltage. The AC/DC responses were measured to evaluate the performance of the 2A-PDMS-MEMS scanning mirror. The maximum scanning angles were measured as ±16.6 deg and ±11.6 deg along the X and Y axes, respectively, and the corresponding field of view was 29.8 mm×20.5 mm with an optical focal length of 50 mm. The resonance frequencies were 82 and 57 Hz along the X and Y axes, respectively. Finally, in vivo B-scan and volumetric OCT images of human fingertips and palms were successfully acquired using the developed SD-OCT system based on the 2A-PDMS-MEMS scanning mirror.

  11. Scanning Laser Radar Development for Solar System Exploration Applications

    NASA Technical Reports Server (NTRS)

    Tratt, D.; Menzies, R.; Bartman, R.; Hemmati, H.

    2000-01-01

    The Jet Propulsion Laboratory (JPL) has recently established an accelerated development initiative to enable high-resolution active optical ranging and terrain mapping capabilities for a series of upcoming Solar System exploration missions.

  12. Scanning SQUID microscope system for geological samples: system integration and initial evaluation

    NASA Astrophysics Data System (ADS)

    Oda, Hirokuni; Kawai, Jun; Miyamoto, Masakazu; Miyagi, Isoji; Sato, Masahiko; Noguchi, Atsushi; Yamamoto, Yuhji; Fujihira, Jun-ichi; Natsuhara, Nobuyoshi; Aramaki, Yoshiyasu; Masuda, Takashige; Xuan, Chuang

    2016-11-01

    We have developed a high-resolution scanning superconducting quantum interference device (SQUID) microscope for imaging the magnetic field of geological samples at room temperature. In this paper, we provide details about the scanning SQUID microscope system, including the magnetically shielded box (MSB), the XYZ stage, data acquisition by the system, and initial evaluation of the system. The background noise in a two-layered PC permalloy MSB is approximately 40-50 pT. The long-term drift of the system is approximately ≥1 nT, which can be reduced by drift correction for each measurement line. The stroke of the XYZ stage is 100 mm × 100 mm with an accuracy of 10 µm, which was confirmed by laser interferometry. A SQUID chip has a pick-up area of 200 μm × 200 μm with an inner hole of 30 μm × 30 μm. The sensitivity is 722.6 nT/V. The flux-locked loop has four gains, i.e., ×1, ×10, ×100, and ×500. An analog-to-digital converter allows analog voltage input in the range of about ±7.5 V in 0.6-mV steps. The maximum dynamic range is approximately ±5400 nT, and the minimum digitizable magnetic field is 0.9 pT. The sensor-to-sample distance is measured with a precision line current, which gives the minimum of 200 µm. Considering the size of pick-up coil, sensor-to-sample distance, and the accuracy of XYZ stage, spacial resolution of the system is 200 µm. We developed the software used to measure the sensor-to-sample distance with line scan data, and the software to acquire data and control the XYZ stage for scanning. We also demonstrate the registration of the magnetic image relative to the optical image by using a pair of point sources placed on the corners of a sample holder outside of a thin section placed in the middle of the sample holder. Considering the minimum noise estimate of the current system, the theoretical detection limit of a single magnetic dipole is 1 × 10-14 Am2. The new instrument is a powerful tool that could be used in various

  13. A new generation scanning system for the high-speed analysis of nuclear emulsions

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Galati, G.; Lauria, A.; Montesi, M. C.; Tioukov, V.; Vladymyrov, M.

    2016-06-01

    The development of automatic scanning systems was a fundamental issue for large scale neutrino detectors exploiting nuclear emulsions as particle trackers. Such systems speed up significantly the event analysis in emulsion, allowing the feasibility of experiments with unprecedented statistics. In the early 1990s, R&D programs were carried out by Japanese and European laboratories leading to automatic scanning systems more and more efficient. The recent progress in the technology of digital signal processing and of image acquisition allows the fulfillment of new systems with higher performances. In this paper we report the description and the performance of a new generation scanning system able to operate at the record speed of 84 cm2/hour and based on the Large Angle Scanning System for OPERA (LASSO) software infrastructure developed by the Naples scanning group. Such improvement, reduces the scanning time by a factor 4 with respect to the available systems, allowing the readout of huge amount of nuclear emulsions in reasonable time. This opens new perspectives for the employment of such detectors in a wider variety of applications.

  14. A scanning spot-beam satellite communication system via transponder with delay

    NASA Astrophysics Data System (ADS)

    Iwasaki, K.; Teshirogi, T.

    1981-07-01

    A TDMA satellite communication system with a spot beam scanned rapidly over the entire service area is discussed, and a configuration of a satellite transponder is proposed, which has an up-link and a down-link beam simultaneously controlled in the same sequence. A comparison is made with Reudink's (1977) system, and it is shown that the switching rate of the down-link beam for the present system can handle high power and thus be reduced to a fraction of Reudink's system. The configuration of the present antenna system would also be simpler in the case of coexistence of a fixed multibeam and scanning spot-beam system.

  15. An Automated Medical Information Management System (OpScan-MIMS) in a Clinical Setting

    PubMed Central

    Margolis, S.; Baker, T.G.; Ritchey, M.G.; Alterescu, S.; Friedman, C.

    1981-01-01

    This paper describes an automated medical information management system within a clinic setting. The system includes an optically scanned data entry system (OpScan), a generalized, interactive retrieval and storage software system(Medical Information Management System, MIMS) and the use of time-sharing. The system has the advantages of minimal hardware purchase and maintenance, rapid data entry and retrieval, user-created programs, no need for user knowledge of computer language or technology and is cost effective. The OpScan-MIMS system has been operational for approximately 16 months in a sexually transmitted disease clinic. The system's application to medical audit, quality assurance, clinic management and clinical training are demonstrated.

  16. Human abdomen recognition using camera and force sensor in medical robot system for automatic ultrasound scan.

    PubMed

    Bin Mustafa, Ammar Safwan; Ishii, Takashi; Matsunaga, Yoshiki; Nakadate, Ryu; Ishii, Hiroyuki; Ogawa, Kouji; Saito, Akiko; Sugawara, Motoaki; Niki, Kiyomi; Takanishi, Atsuo

    2013-01-01

    Physicians use ultrasound scans to obtain real-time images of internal organs, because such scans are safe and inexpensive. However, people in remote areas face difficulties to be scanned due to aging society and physician's shortage. Hence, it is important to develop an autonomous robotic system to perform remote ultrasound scans. Previously, we developed a robotic system for automatic ultrasound scan focusing on human's liver. In order to make it a completely autonomous system, we present in this paper a way to autonomously localize the epigastric region as the starting position for the automatic ultrasound scan. An image processing algorithm marks the umbilicus and mammary papillae on a digital photograph of the patient's abdomen. Then, we made estimation for the location of the epigastric region using the distances between these landmarks. A supporting algorithm distinguishes rib position from epigastrium using the relationship between force and displacement. We implemented these algorithms with the automatic scanning system into an apparatus: a Mitsubishi Electric's MELFA RV-1 six axis manipulator. Tests on 14 healthy male subjects showed the apparatus located the epigastric region with a success rate of 94%. The results suggest that image recognition was effective in localizing a human body part.

  17. Optimization of electrostatic lens systems for low-energy scanning microcolumn applications

    SciTech Connect

    Oh, Tae-Sik; Kim, Dae-Wook; Ahn, Seungjoon; Kim, Young Chul; Kim, Ho-Seob; Ahn, Seong Joon

    2008-11-15

    The optimization of a low-energy scanning microcolumn is proposed by adopting a modified Einzel lens sandwiched between an aligner and a deflector. The modified Einzel lens is composed of four electrodes, and the two center electrodes are specially designed quadrupole lenses having keyhole type rather than circular apertures. The outer electrodes of the Einzel lens having circular apertures are grounded, and the quadrupole lens is operated by applying the quadrupole voltages. The effects of the separated deflector system and the static quadrupole lens were investigated by analyzing the scanning electron beam spot at the target, and the results show that the proposed system can improve the performance of the scanning microcolumn.

  18. Identification of Hafnia alvei with the MicroScan WalkAway System

    PubMed Central

    Rodríguez, L. A.; Vivas, J.; Gallardo, C. S.; Acosta, F.; Barbeyto, L.; Real, F.

    1999-01-01

    Hafnia alvei is a gram-negative facultatively anaerobic bacillus that belongs to the family Enterobacteriaceae. This organism is a causative agent of intestinal disorders and is found in different environments. H. alvei has received increased clinical attention as a cause of different infections in humans. This study was performed to compare the MicroScan WalkAway automated identification system in conjunction with the new MicroScan Combo Negative type 1S panels with conventional biochemical methods for identification of 21 H. alvei strains. The MicroScan WalkAway system was found capable of correctly identifying 20 of the 21 strains tested. PMID:10565961

  19. Hierarchical, Three-Dimensional Measurement System for Crime Scene Scanning.

    PubMed

    Marcin, Adamczyk; Maciej, Sieniło; Robert, Sitnik; Adam, Woźniak

    2017-02-02

    We present a new generation of three-dimensional (3D) measuring systems, developed for the process of crime scene documentation. This measuring system facilitates the preparation of more insightful, complete, and objective documentation for crime scenes. Our system reflects the actual requirements for hierarchical documentation, and it consists of three independent 3D scanners: a laser scanner for overall measurements, a situational structured light scanner for more minute measurements, and a detailed structured light scanner for the most detailed parts of tscene. Each scanner has its own spatial resolution, of 2.0, 0.3, and 0.05 mm, respectively. The results of interviews we have conducted with technicians indicate that our developed 3D measuring system has significant potential to become a useful tool for forensic technicians. To ensure the maximum compatibility of our measuring system with the standards that regulate the documentation process, we have also performed a metrological validation and designated the maximum permissible length measurement error EMPE for each structured light scanner. In this study, we present additional results regarding documentation processes conducted during crime scene inspections and a training session.

  20. Fundamental radiological and geometric performance of two types of proton beam modulated discrete scanning systems

    SciTech Connect

    Farr, J. B.; Schoenenberg, D.; Dessy, F.; De Wilde, O.; Bietzer, O.

    2013-07-15

    Purpose: The purpose of this investigation was to compare and contrast the measured fundamental properties of two new types of modulated proton scanning systems. This provides a basis for clinical expectations based on the scanned beam quality and a benchmark for computational models. Because the relatively small beam and fast scanning gave challenges to the characterization, a secondary purpose was to develop and apply new approaches where necessary to do so.Methods: The following performances of the proton scanning systems were investigated: beamlet alignment, static in-air beamlet size and shape, scanned in-air penumbra, scanned fluence map accuracy, geometric alignment of scanning system to isocenter, maximum field size, lateral and longitudinal field uniformity of a 1 l cubic uniform field, output stability over time, gantry angle invariance, monitoring system linearity, and reproducibility. A range of detectors was used: film, ionization chambers, lateral multielement and longitudinal multilayer ionization chambers, and a scintillation screen combined with a digital video camera. Characterization of the scanned fluence maps was performed with a software analysis tool.Results: The resulting measurements and analysis indicated that the two types of delivery systems performed within specification for those aspects investigated. The significant differences were observed between the two types of scanning systems where one type exhibits a smaller spot size and associated penumbra than the other. The differential is minimum at maximum energy and increases inversely with decreasing energy. Additionally, the large spot system showed an increase in dose precision to a static target with layer rescanning whereas the small spot system did not.Conclusions: The measured results from the two types of modulated scanning types of system were consistent with their designs under the conditions tested. The most significant difference between the types of system was their proton

  1. The optical system of the Along Track Scanning Radiometer (ATSR)

    NASA Astrophysics Data System (ADS)

    Gray, Peter F.

    1986-01-01

    The optical arrangement of ATSR (for sea-surface temperature measurement) is described. Radiometric constraints upon the sizes, positions and temperatures of stops in the system are discussed and their impact on the design summarized. Data on the predicted image resolution are given, allowing for residual geometrical aberrations, diffraction, signal integration time and a manufacturing/assembly error budget.

  2. Spacelab data analysis using the space plasma computer analysis network (SCAN) system

    NASA Technical Reports Server (NTRS)

    Green, J. L.

    1984-01-01

    The Space-plasma Computer Analysis Network (SCAN) currently connects a large number of U.S. Spacelab investigators into a common computer network. Used primarily by plasma physics researchers at present, SCAN provides access to Spacelab investigators in other areas of space science, to Spacelab and non-Spacelab correlative data bases, and to large Class VI computational facilities for modeling. SCAN links computers together at remote institutions used by space researchers, utilizing commercially available software for computer-to-computer communications. Started by the NASA's Office of Space Science in mid 1980, SCAN presently contains ten system nodes located at major universities and space research laboratories, with fourteen new nodes projected for the near future. The Stanford University computer gateways allow SCAN users to connect onto the ARPANET and TELENET overseas networks.

  3. Developing and improving a scanning system for dosimetric applications

    SciTech Connect

    Perez, P.; Galvan, V.; Castellanoa, G.; Valente, M.

    2010-08-04

    Radiotherapy is nowadays one of the most used techniques for the treatment of different pathologies, particularly cancer diseases. The accuracy regarding the application of these treatments, which are planned according to patient information, depends mainly on the dosimetric measurements of absorbed dose within irradiated tissues. The present work is devoted to the study, design and construction of an original device capable of performing visible light transmission measurements in order to analyze Fricke gel dosimeters. Furthermore, a suitable bi-dimensional positioning system along with a dedicated control system and image processing software has been adapted to the dosimetric device in order to perform 2D dose mapping. The obtained results confirm the feasibility of the proposed method, therefore suggesting its potentiality for clinical applications.

  4. Recording and Scanning Advances in Cartographic EBR Systems.

    DTIC Science & Technology

    1981-06-01

    34Cartographic Electron Beam Recording," 2nd Annual William T. Pecora Memorial Symposium on Mapping and Remote Sensing Data, Sponsored ASP, USGS, NASA...using the experimental Cartographic EBR System. These were: (a) GAF Electrostatic Film - toner processed (b) GAF Direct Recording Materials - no...processing required (c) Kodak Direct Recording ESR-l - no processing required (d) GAF Electrostatic Films - color toner processed (e) Kodak S0214

  5. Development of online lines-scan imaging system for chicken inspection and differentiation

    NASA Astrophysics Data System (ADS)

    Yang, Chun-Chieh; Chan, Diane E.; Chao, Kuanglin; Chen, Yud-Ren; Kim, Moon S.

    2006-10-01

    An online line-scan imaging system was developed for differentiation of wholesome and systemically diseased chickens. The hyperspectral imaging system used in this research can be directly converted to multispectral operation and would provide the ideal implementation of essential features for data-efficient high-speed multispectral classification algorithms. The imaging system consisted of an electron-multiplying charge-coupled-device (EMCCD) camera and an imaging spectrograph for line-scan images. The system scanned the surfaces of chicken carcasses on an eviscerating line at a poultry processing plant in December 2005. A method was created to recognize birds entering and exiting the field of view, and to locate a Region of Interest on the chicken images from which useful spectra were extracted for analysis. From analysis of the difference spectra between wholesome and systemically diseased chickens, four wavelengths of 468 nm, 501 nm, 582 nm and 629 nm were selected as key wavelengths for differentiation. The method of locating the Region of Interest will also have practical application in multispectral operation of the line-scan imaging system for online chicken inspection. This line-scan imaging system makes possible the implementation of multispectral inspection using the key wavelengths determined in this study with minimal software adaptations and without the need for cross-system calibration.

  6. Performances of the scanning system for the CNAO center of oncological hadron therapy

    NASA Astrophysics Data System (ADS)

    Giordanengo, S.; Donetti, M.; Marchetto, F.; Ansarinejad, A.; Attili, A.; Bourhaleb, F.; Burini, F.; Cirio, R.; Fabbricatore, P.; Voelker, F.; Garella, M. A.; Incurvati, M.; Monaco, V.; Pardo, J.; Peroni, C.; Russo, G.; Sacchi, R.; Taddia, G.; Zampieri, A.

    2010-02-01

    In hadron therapy one of the most advanced methods for beam delivery is the active scanning technique which uses fast scanning magnets to drive a narrow particle beam across the target. The Centro Nazionale di Adroterapia Oncologica (CNAO) will treat tumours with this technique. The CNAO scanning system includes two identical dipole magnets for horizontal and vertical beam deflection, each one connected to a fast power supply. The dose delivery system exploits a set of monitor chambers to measure the fluence and position of the beam and drives the beam during the treatment by controlling the sequence of currents set by the power supplies. A test of the dynamic performance of the scanning system has been performed using a Hall probe to measure the field inside the magnet and the results are presented in this paper.

  7. The remote measurement of tornado-like flows employing a scanning laser Doppler system

    NASA Technical Reports Server (NTRS)

    Jeffreys, H. B.; Bilbro, J. W.; Dimarzio, C.; Sonnenschein, C.; Toomey, D.

    1977-01-01

    The paper deals with a scanning laser Doppler velocimeter system employed in a test program for measuring naturally occurring tornado-like phenomena, known as dust devils. A description of the system and the test program is followed by a discussion of the data processing techniques and data analysis. The system uses a stable 15-W CO2 laser with the beam expanded and focused by a 12-inch telescope. Range resolution is obtained by focusing the optical system. The velocity of each volume of air (scanned in a horizontal plane) is determined from spectral analysis of the heterodyne signal. Results derived from the measurement program and data/system analyses are examined.

  8. Remote Gamma Scanning System for Characterization of BWR and PWR Fuel Rod Sections

    SciTech Connect

    Crowell, Shannon L.; Alzheimer, James M.

    2011-08-08

    Sometimes challenges with the design and deployment of automated equipment in remote environments deals more with the constraints imposed by the remote environment than it does with the details of the automation. This paper discusses the development of a scanning system used to provide gamma radiation profiles of irradiated fuel rod segments. The system needed the capability to provide axial scans of cut segments of BWR and PWR fuel rods. The scanning location is A-Cell at the Radiochemical Processing Laboratory (RPL) at the Hanford site in Washington State. The criteria for the scanning equipment included axial scanning increments of a tenth of an inch or less, ability to scan fuel rods with diameters ranging from 3/8 inch to 5/8 inch in diameter, and fuel rod segments up to seven feet in length. Constraints imposed by the environment included having the gamma detector and operator controls on the outside of the hot cell and the scanning hardware on the inside of the hot cell. This entailed getting a narrow, collimated beam of radiation from the fuel rod to the detector on the outside of the hot cell while minimizing the radiation exposure caused by openings for the wires and cables traversing the hot cell walls. Setup and operation of all of the in-cell hardware needed to accommodate limited access ports and use of hot cell manipulators. The radiation levels inside the cell also imposed constraints on the materials used.

  9. Review of P-scan computer-based ultrasonic inservice inspection system. Supplement 1

    SciTech Connect

    Harris, R.V. Jr.; Angel, L.J.

    1995-12-01

    This Supplement reviews the P-scan system, a computer-based ultrasonic system used for inservice inspection of piping and other components in nuclear power plants. The Supplement was prepared using the methodology described in detail in Appendix A of NUREG/CR-5985, and is based on one month of using the system in a laboratory. This Supplement describes and characterizes: computer system, ultrasonic components, and mechanical components; scanning, detection, digitizing, imaging, data interpretation, operator interaction, data handling, and record-keeping. It includes a general description, a review checklist, and detailed results of all tests performed.

  10. Design and verification of the miniature optical system for small object surface profile fast scanning

    NASA Astrophysics Data System (ADS)

    Chi, Sheng; Lee, Shu-Sheng; Huang, Jen, Jen-Yu; Lai, Ti-Yu; Jan, Chia-Ming; Hu, Po-Chi

    2016-04-01

    As the progress of optical technologies, different commercial 3D surface contour scanners are on the market nowadays. Most of them are used for reconstructing the surface profile of mold or mechanical objects which are larger than 50 mm×50 mm× 50 mm, and the scanning system size is about 300 mm×300 mm×100 mm. There are seldom optical systems commercialized for surface profile fast scanning for small object size less than 10 mm×10 mm×10 mm. Therefore, a miniature optical system has been designed and developed in this research work for this purpose. Since the most used scanning method of such system is line scan technology, we have developed pseudo-phase shifting digital projection technology by adopting projecting fringes and phase reconstruction method. A projector was used to project a digital fringe patterns on the object, and the fringes intensity images of the reference plane and of the sample object were recorded by a CMOS camera. The phase difference between the plane and object can be calculated from the fringes images, and the surface profile of the object was reconstructed by using the phase differences. The traditional phase shifting method was accomplished by using PZT actuator or precisely controlled motor to adjust the light source or grating and this is one of the limitations for high speed scanning. Compared with the traditional optical setup, we utilized a micro projector to project the digital fringe patterns on the sample. This diminished the phase shifting processing time and the controlled phase differences between the shifted phases become more precise. Besides, the optical path design based on a portable device scanning system was used to minimize the size and reduce the number of the system components. A screwdriver section about 7mm×5mm×5mm has been scanned and its surface profile was successfully restored. The experimental results showed that the measurement area of our system can be smaller than 10mm×10mm, the precision reached to

  11. Digital processing of side-scan sonar data with the Woods Hole image processing system software

    USGS Publications Warehouse

    Paskevich, Valerie F.

    1992-01-01

    Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low-resolution side-scan sonar data. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for processing side-scan sonar data. This report describes the steps required to process the collected data and to produce an image that has equal along- and across-track resol

  12. A frequency scanning method for the identification of harmonic instabilities in HVDC systems

    SciTech Connect

    Jiang, X.; Gole, A.M.

    1995-10-01

    A Frequency Scanning Method is introduced in the paper to obtain a more accurate frequency characteristic for identifying harmonic instability in HVdc systems. An example of the application is used to identify the resonance frequencies in the CIGRE benchmark model. The paper shows that the Benchmark model is not tuned to the resonance frequency that it was designed for. Using the scanning method, the resonance frequency of the benchmark model may be shifted to demonstrate a simulation of core-saturation type instability.

  13. Development of a hybrid atomic force microscopic measurement system combined with white light scanning interferometry.

    PubMed

    Guo, Tong; Wang, Siming; Dorantes-Gonzalez, Dante J; Chen, Jinping; Fu, Xing; Hu, Xiaotang

    2012-01-01

    A hybrid atomic force microscopic (AFM) measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system's dynamic response, the frequency modulation (FM) mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system's good measurement performance and feasibility of the hybrid measurement method.

  14. Autoblocker: a system for detecting and blocking of network scanning based on analysis of netflow data

    SciTech Connect

    Bobyshev, A.; Lamore, D.; Demar, P.; /Fermilab

    2004-12-01

    In a large campus network, such at Fermilab, with tens of thousands of nodes, scanning initiated from either outside of or within the campus network raises security concerns. This scanning may have very serious impact on network performance, and even disrupt normal operation of many services. In this paper we introduce a system for detecting and automatic blocking excessive traffic of different kinds of scanning, DoS attacks, virus infected computers. The system, called AutoBlocker, is a distributed computing system based on quasi-real time analysis of network flow data collected from the border router and core switches. AutoBlocker also has an interface to accept alerts from IDS systems (e.g. BRO, SNORT) that are based on other technologies. The system has multiple configurable alert levels for the detection of anomalous behavior and configurable trigger criteria for automated blocking of scans at the core or border routers. It has been in use at Fermilab for about 2 years, and has become a very valuable tool to curtail scan activity within the Fermilab campus network.

  15. Georeferenced scanning system to estimate the leaf wall area in tree crops.

    PubMed

    del-Moral-Martínez, Ignacio; Arnó, Jaume; Escolà, Alexandre; Sanz, Ricardo; Masip-Vilalta, Joan; Company-Messa, Joaquim; Rosell-Polo, Joan R

    2015-04-10

    This paper presents the use of a terrestrial light detection and ranging (LiDAR) system to scan the vegetation of tree crops to estimate the so-called pixelated leaf wall area (PLWA). Scanning rows laterally and considering only the half-canopy vegetation to the line of the trunks, PLWA refers to the vertical projected area without gaps detected by LiDAR. As defined, PLWA may be different depending on the side from which the LiDAR is applied. The system is completed by a real-time kinematic global positioning system (RTK-GPS) sensor and an inertial measurement unit (IMU) sensor for positioning. At the end, a total leaf wall area (LWA) is computed and assigned to the X, Y position of each vertical scan. The final value of the area depends on the distance between two consecutive scans (or horizontal resolution), as well as the number of intercepted points within each scan, since PLWA is only computed when the laser beam detects vegetation. To verify system performance, tests were conducted related to the georeferencing task and synchronization problems between GPS time and central processing unit (CPU) time. Despite this, the overall accuracy of the system is generally acceptable. The Leaf Area Index (LAI) can then be estimated using PLWA as an explanatory variable in appropriate linear regression models.

  16. Georeferenced Scanning System to Estimate the Leaf Wall Area in Tree Crops

    PubMed Central

    del-Moral-Martínez, Ignacio; Arnó, Jaume; Escolà, Alexandre; Sanz, Ricardo; Masip-Vilalta, Joan; Company-Messa, Joaquim; Rosell-Polo, Joan R.

    2015-01-01

    This paper presents the use of a terrestrial light detection and ranging (LiDAR) system to scan the vegetation of tree crops to estimate the so-called pixelated leaf wall area (PLWA). Scanning rows laterally and considering only the half-canopy vegetation to the line of the trunks, PLWA refers to the vertical projected area without gaps detected by LiDAR. As defined, PLWA may be different depending on the side from which the LiDAR is applied. The system is completed by a real-time kinematic global positioning system (RTK-GPS) sensor and an inertial measurement unit (IMU) sensor for positioning. At the end, a total leaf wall area (LWA) is computed and assigned to the X, Y position of each vertical scan. The final value of the area depends on the distance between two consecutive scans (or horizontal resolution), as well as the number of intercepted points within each scan, since PLWA is only computed when the laser beam detects vegetation. To verify system performance, tests were conducted related to the georeferencing task and synchronization problems between GPS time and central processing unit (CPU) time. Despite this, the overall accuracy of the system is generally acceptable. The Leaf Area Index (LAI) can then be estimated using PLWA as an explanatory variable in appropriate linear regression models. PMID:25868079

  17. Nondestructive x-ray microanalysis bidirectional scanning and data acquisition system

    SciTech Connect

    Lawson, R.L.

    1989-09-12

    A system for making fast scans of specimens and acquiring data was developed at the oak Ridge Y-12 Plant. An LSI 11/23 computer using the RT11 operating system controls the scan and data acquisition. Scan software was written which would program a Unidex III stepping motor controller to make the scan motions while the position was monitored and the data acquired through the computer`s timer/counter boards from the multichannel analyzer`s four region of interest (ROI) outputs. Small areas of a part or specimen are scanned by moving the part back and forth in the x-ray beam using stepping motor actuated tables. A detector receives the scattered x-rays from the part and sends a signal to the multichannel analyzer which digitizes it. After the data has been acquired using the scan computer, the data is then transferred to a PC to where it is processed and an image is generated and displayed for analysis.

  18. Multi-frequency AOM for multi-beam laser scanning exposure system

    NASA Astrophysics Data System (ADS)

    Shinada, Hidetoshi

    2016-10-01

    Digital printing systems recorded on films or computer to plates (CTPs) have been required to improve their productivity and image quality. Under the circumstance, a printing technology of the multi-beam laser scanning for the drum capstan system, which is almost the same as optics configuration as the flat bed system, was developed using a newly developed multi-frequency acousto-optic modulator (AOM) as a key device instead of ultra-fast scanning devices toward a main scan direction. The multi-frequency AOM was developed with phased array-type transducers, achieving a wider bandwidth of over 160 MHz. The design consisted of a simultaneous three beams generation with interlace scan to avoid the beat effect by adjacent Doppler-shifted beams, which consequently attained the fastest recording speed of 5.0 mm/s compared with 2.0-3.0 mm/s of existing systems in those days. Furthermore, a couple of critical parameters of the multi-frequency AOM are studied, for example, a treatment of third-order intermodulation and also beat effect in connection with photosensitive media. As a result, the necessity of interlaces scanning to obtain good image quality without beat effect and also to allow a lower laser power to apply is proposed.

  19. Recommendations for the design and the installation of large laser scanning microscopy systems

    NASA Astrophysics Data System (ADS)

    Helm, P. Johannes

    2012-03-01

    Laser Scanning Microscopy (LSM) has since the inventions of the Confocal Scanning Laser Microscope (CLSM) and the Multi Photon Laser Scanning Microscope (MPLSM) developed into an essential tool in contemporary life science and material science. The market provides an increasing number of turn-key and hands-off commercial LSM systems, un-problematic to purchase, set up and integrate even into minor research groups. However, the successful definition, financing, acquisition, installation and effective use of one or more large laser scanning microscopy systems, possibly of core facility character, often requires major efforts by senior staff members of large academic or industrial units. Here, a set of recommendations is presented, which are helpful during the process of establishing large systems for confocal or non-linear laser scanning microscopy as an effective operational resource in the scientific or industrial production process. Besides the description of technical difficulties and possible pitfalls, the article also illuminates some seemingly "less scientific" processes, i.e. the definition of specific laboratory demands, advertisement of the intention to purchase one or more large systems, evaluation of quotations, establishment of contracts and preparation of the local environment and laboratory infrastructure.

  20. Monte Carlo simulation of Ray-Scan 64 PET system and performance evaluation using GATE toolkit

    NASA Astrophysics Data System (ADS)

    Li, Suying; Zhang, Qiushi; Vuletic, Ivan; Xie, Zhaoheng; Yang, Kun; Ren, Qiushi

    2017-02-01

    In this study, we aimed to develop a GATE model for the simulation of Ray-Scan 64 PET scanner and model its performance characteristics. A detailed implementation of system geometry and physical process were included in the simulation model. Then we modeled the performance characteristics of Ray-Scan 64 PET system for the first time, based on National Electrical Manufacturers Association (NEMA) NU-2 2007 protocols and validated the model against experimental measurement, including spatial resolution, sensitivity, counting rates and noise equivalent count rate (NECR). Moreover, an accurate dead time module was investigated to simulate the counting rate performance. Overall results showed reasonable agreement between simulation and experimental data. The validation results showed the reliability and feasibility of the GATE model to evaluate major performance of Ray-Scan 64 PET system. It provided a useful tool for a wide range of research applications.

  1. Innovative Gamma Ray Spectrometer Detection Systems for Conducting Scanning Surveys on Challenging Terrain - 13583

    SciTech Connect

    Palladino, Carl; Mason, Bryan; Engle, Matt; LeVangie, James; Dempsey, Gregg; Klemovich, Ron

    2013-07-01

    The Santa Susana Field Laboratory located near Simi Valley, California was investigated to determine the nature and extent of gamma radiation anomalies. The primary objective was to conduct gamma scanning surveys over 100 percent of the approximately 1,906,000 square meters (471 acre) project site with the most sensitive detection system possible. The site had challenging topography that was not conducive to traditional gamma scanning detection systems. Terrain slope varied from horizontal to 48 degrees and the ground surface ranged from flat, grassy meadows to steep, rocky hillsides. In addition, the site was home to many protected endangered plant and animal species, and archaeologically significant sites that required minimal to no disturbance of the ground surface. Therefore, four innovative and unique gamma ray spectrometer detection systems were designed and constructed to successfully conduct gamma scanning surveys of approximately 1,076,000 square meters (266 acres) of the site. (authors)

  2. How do interruptions impact nurses' visual scanning patterns when using barcode medication administration systems?

    PubMed

    He, Ze; Marquard, Jenna L; Henneman, Philip L

    2014-01-01

    While barcode medication administration (BCMA) systems have the potential to reduce medication errors, they may introduce errors, side effects, and hazards into the medication administration process. Studies of BCMA systems should therefore consider the interrelated nature of health information technology (IT) use and sociotechnical systems. We aimed to understand how the introduction of interruptions into the BCMA process impacts nurses' visual scanning patterns, a proxy for one component of cognitive processing. We used an eye tracker to record nurses' visual scanning patterns while administering a medication using BCMA. Nurses either performed the BCMA process in a controlled setting with no interruptions (n=25) or in a real clinical setting with interruptions (n=21). By comparing the visual scanning patterns between the two groups, we found that nurses in the interruptive environment identified less task-related information in a given period of time, and engaged in more information searching than information processing.

  3. How do Interruptions Impact Nurses’ Visual Scanning Patterns When Using Barcode Medication Administration Systems?

    PubMed Central

    He, Ze; Marquard, Jenna L.; Henneman, Philip L.

    2014-01-01

    While barcode medication administration (BCMA) systems have the potential to reduce medication errors, they may introduce errors, side effects, and hazards into the medication administration process. Studies of BCMA systems should therefore consider the interrelated nature of health information technology (IT) use and sociotechnical systems. We aimed to understand how the introduction of interruptions into the BCMA process impacts nurses’ visual scanning patterns, a proxy for one component of cognitive processing. We used an eye tracker to record nurses’ visual scanning patterns while administering a medication using BCMA. Nurses either performed the BCMA process in a controlled setting with no interruptions (n=25) or in a real clinical setting with interruptions (n=21). By comparing the visual scanning patterns between the two groups, we found that nurses in the interruptive environment identified less task-related information in a given period of time, and engaged in more information searching than information processing. PMID:25954449

  4. Calibration for single multi-mode fiber digital scanning microscopy imaging system

    NASA Astrophysics Data System (ADS)

    Yin, Zhe; Liu, Guodong; Liu, Bingguo; Gan, Yu; Zhuang, Zhitao; Chen, Fengdong

    2015-11-01

    Single multimode fiber (MMF) digital scanning imaging system is a development tendency of modern endoscope. We concentrate on the calibration method of the imaging system. Calibration method comprises two processes, forming scanning focused spots and calibrating the couple factors varied with positions. Adaptive parallel coordinate algorithm (APC) is adopted to form the focused spots at the multimode fiber (MMF) output. Compare with other algorithm, APC contains many merits, i.e. rapid speed, small amount calculations and no iterations. The ratio of the optics power captured by MMF to the intensity of the focused spots is called couple factor. We setup the calibration experimental system to form the scanning focused spots and calculate the couple factors for different object positions. The experimental result the couple factor is higher in the center than the edge.

  5. Scanning Ultrasonic Spectroscopy System Developed for the Inspection of Composite Flywheels

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.; Baaklini, George Y.

    2002-01-01

    Composite flywheels are being considered as replacements for chemical batteries aboard the International Space Station. A flywheel stores energy in a spinning mass that can turn a generator to meet power demands. Because of the high rotational speeds of the spinning mass, extensive testing of the flywheel system must be performed prior to flight certification. With this goal in mind, a new scanning system has been developed at the NASA Glenn Research Center for the nondestructive inspection of composite flywheels and flywheel subcomponents. The system uses ultrasonic waves to excite a material and examines the response to detect and locate flaws and material variations. The ultrasonic spectroscopy system uses a transducer to send swept-frequency ultrasonic waves into a test material and then receives the returning signal with a second transducer. The received signal is then analyzed in the frequency domain using a fast Fourier transform. A second fast Fourier transform is performed to examine the spacing of the peaks in the frequency domain. The spacing of the peaks is related to the standing wave resonances that are present in the material because of the constructive and destructive interferences of the waves in the full material thickness as well as in individual layers within the material. Material variations and flaws are then identified by changes in the amplitudes and positions of the peaks in both the frequency and resonance spacing domains. This work, conducted under a grant through the Cleveland State University, extends the capabilities of an existing point-by-point ultrasonic spectroscopy system, thus allowing full-field automated inspection. Results of an ultrasonic spectroscopy scan of a plastic cylinder with intentionally seeded flaws. The result of an ultrasonic spectroscopy scan of a plastic cylinder used as a proof-of-concept specimen is shown. The cylinder contains a number of flat bottomed holes of various sizes and shapes. The scanning system

  6. A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS

    SciTech Connect

    Schmidt, K. F.; Little, J. R.; Ellingson, W. A.; Green, W.

    2009-03-03

    A portable, microwave interference scanning system, that can be used in situ, with one-sided, non-contact access, has been developed. It has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and non-ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper will present details of the system and discuss results obtained.

  7. A 3D acquisition system combination of structured-light scanning and shape from silhouette

    NASA Astrophysics Data System (ADS)

    Sun, Changku; Tao, Li; Wang, Peng; He, Li

    2006-05-01

    A robust and accurate three dimensional (3D) acquisition system is presented, which is a combination of structured-light scanning and shape from silhouette. Using common world coordinate system, two groups of point data can be integrated into the final complete 3D model without any integration and registration algorithm. The mathematics model of structured-light scanning is described in detail, and the shape from silhouette algorithm is introduced as well. The complete 3D model of a cup with a handle is obtained successfully by the proposed technique. At last the measurement on a ball bearing is performed, with the measurement precision better than 0.15 mm.

  8. A new fast scanning system for the measurement of large angle tracks in nuclear emulsions

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Galati, G.; Lauria, A.; Montesi, M. C.; Pupilli, F.; Shchedrina, T.; Tioukov, V.; Vladymyrov, M.

    2015-11-01

    Nuclear emulsions have been widely used in particle physics to identify new particles through the observation of their decays thanks to their unique spatial resolution. Nevertheless, before the advent of automatic scanning systems, the emulsion analysis was very demanding in terms of well trained manpower. Due to this reason, they were gradually replaced by electronic detectors, until the '90s, when automatic microscopes started to be developed in Japan and in Europe. Automatic scanning was essential to conceive large scale emulsion-based neutrino experiments like CHORUS, DONUT and OPERA. Standard scanning systems have been initially designed to recognize tracks within a limited angular acceptance (θ lesssim 30°) where θ is the track angle with respect to a line perpendicular to the emulsion plane. In this paper we describe the implementation of a novel fast automatic scanning system aimed at extending the track recognition to the full angular range and improving the present scanning speed. Indeed, nuclear emulsions do not have any intrinsic limit to detect particle direction. Such improvement opens new perspectives to use nuclear emulsions in several fields in addition to large scale neutrino experiments, like muon radiography, medical applications and dark matter directional detection.

  9. Initial Tests and Accuracy Assesment of a Compact Mobile Laser Scanning System

    NASA Astrophysics Data System (ADS)

    Julge, K.; Ellmann, A.; Vajakas, T.; Kolka, R.

    2016-06-01

    Mobile laser scanning (MLS) is a faster and cost-effective alternative to static laser scanning, even though there is a slight trade-off in accuracy. This contribution describes a compact mobile laser scanning system mounted on a vehicle. The technical parameters of the used system components, i.e. a small LIDAR sensor Velodyne VLP-16 and a dual antenna GNSS/INS system Advanced Navigation Spatial Dual, are reviewed, along with the integration of these components for spatial data acquisition. Calculation principles of 3D coordinates from the real-time data of all the involved sensors are discussed. The field tests were carried out in a controlled environment of a parking lot and at different velocities. Experiments were carried out to test the ability of the GNSS/INS system to cope with difficult conditions, e.g. sudden movements due to cornering or swerving. The accuracy of the resulting MLS point cloud is evaluated with respect to high-accuracy static terrestrial laser scanning data. Problems regarding combining LIDAR, GNSS and INS sensors are outlined, as well as the initial accuracy assessments. Initial tests revealed errors related to insufficient quality of inertial data and a need for the trajectory post-processing calculations. Although this study was carried out while the system was mounted on a car, there is potential for operating the system on an unmanned aerial vehicle, all-terrain vehicle or in a backpack mode due to its relatively compact size.

  10. Development of an automated multisample scanning system for nuclear track etched detectors

    NASA Astrophysics Data System (ADS)

    Tawara, H.; Eda, K.; Takahashi, K.; Doke, T.; Hasebe, N.; Kodaira, S.; Ota, S.; Kurano, M.; Yasuda, N.

    2008-08-01

    We have developed an automated scanning system for handling a large number of nuclear track etched detectors (NTEDs). The system consists of a magazine station for sample storage, a robotic sample loader, a high-speed wide-area digital imaging microscope device (modified HSP-1000) and PitFit software for analyzing etch pits. We investigated the performance of the system using CR-39 plastic NTED samples exposed to high-energy heavy ions and fast neutrons. When applying the system to fast neutron dosimetry, the typical scanning speed was about 100 samples/day with a scan area of 4 cm 2/sample. The neutron doses obtained from a fully automatic measurement agreed closely with those from a semi-automatic measurement. These results indicate the feasibility of fully automatic scanning of CR-39 personal neutron dosimeters. The system is also expected to be applicable to future large-scale experiments using CR-39 plastic and BP-1 glass NTEDs for observing ultraheavy galactic cosmic rays with high mass resolution.

  11. Spatial coherence measurement of a scanning laser system and applicability of the Zernike's approximation to the exit pupil on the scan mirror

    NASA Astrophysics Data System (ADS)

    Kubota, Shigeo

    2012-11-01

    Spatial coherence of the scanning laser beam was observed on the Young's experimental set up using 50-μm-wide, 200-μm-separation double slits, which measured the less than unity fringe visibility in the Fraunhofer diffraction pattern of the double slits illuminated by the scanning laser beam at horizontal scan frequency 21 kHz, while approximately unity in case of the illumination by the laser beam at rest. This fact allow us to use the Zernike's approximation when applying the van Cittert Zernike theorem to the scanning laser system such as the laser pico-projectors in order to estimate its speckle contrast in the projected image on the screen diffuser. The predicted and measured speckle contrasts showed excellent agreement on the screen illuminated by the laser projector.

  12. Influence of scanning system and dentist's level of training in the accuracy of digital impressions

    NASA Astrophysics Data System (ADS)

    Hategan, Simona; Gabor, Alin; Zaharia, Cristian; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Jivanescu, Anca

    2016-03-01

    Background: The principal aim of our study was to evaluate digital impressions, taken with spray powder and powderfree scan systems, in order to determine the influence of the dentist's commitment to training as a critical factor regarding quality. Material and method: Two digital intraoral impression systems from the same manufacture (Sirona) : Apollo DI and CEREC Omnicam, were used to scan 16 crown preparations on teeth on a typodont maxillary model. Because an Apollo Di intraoral camera is a powder system, an adhesive was applied before using the powder spray. Three groups were used to scan the crown preparations in order to determine coating thickness homogeneity. One group consisted of senior year dental students, a second consisted of prosthodontics residents, and the third consisted of prosthodontics specialists. The same procedure was applied with a CEREC Omnicam intraoral camera, which is a powder-free system. By using the two systems software parameters we were able to determine the scanning precision. Results: Homogeneity scores for Apollo Di regarding the spray layer was significantly thinner for all dental surfaces in the first group, while the second group had thinner coatings for buccal and distal surfaces. For the third group, the crown preparations were coated more homogeneously than the first two groups. The powder-free system CEREC Omnicam can, to a degree, mask the lack of experience in direct optical impressions by avoiding the poor quality coating, which can lead to defective marginal adaptation of definitive restoration. Conclusions: The dentist's lack of experience can be mitigated, and partially avoided, by using powder-free systems. At the same time, the dentist can give more time towards learning how to integrate computerized fabricated restoration into the practice. The commitment to training is a critical factor in the successful integration of the technology. In

  13. Design of 220 GHz electronically scanned reflectarrays for confocal imaging systems

    NASA Astrophysics Data System (ADS)

    Hedden, Abigail S.; Dietlein, Charles R.; Wikner, David A.

    2012-09-01

    The authors analyze properties of a 220 GHz imaging system that uses a scanned reflectarray to perform electronic beam scanning of a confocal imager for applications including imaging meter-sized fields of view at 50 m standoff. Designs incorporating reflectarrays with confocal imagers have not been examined previously at these frequencies. We examine tradeoffs between array size, overall system size, and number of achievable image pixels resulting in a realistic architecture capable of meeting the needs of our application. Impacts to imaging performance are assessed through encircled energy calculations, beam pointing accuracy, and examining the number and intensity of quantization lobes that appear over the scan ranges of interest. Over the desired scan range, arrays with 1 and 2-bit phase quantization showed similar array main beam energy efficiencies. Two-bit phase quantization is advantageous in terms of pointing angle error, resulting in errors of at most 15% of the diffraction-limited beam size. However, both phase quantization cases considered resulted in spurious returns over the scan range of interest and other array layouts should be examined to eliminate potential imaging artifacts.

  14. Local imaging of high mobility two-dimensional electron systems with virtual scanning tunneling microscopy

    SciTech Connect

    Pelliccione, M.; Bartel, J.; Goldhaber-Gordon, D.; Sciambi, A.; Pfeiffer, L. N.; West, K. W.

    2014-11-03

    Correlated electron states in high mobility two-dimensional electron systems (2DESs), including charge density waves and microemulsion phases intermediate between a Fermi liquid and Wigner crystal, are predicted to exhibit complex local charge order. Existing experimental studies, however, have mainly probed these systems at micron to millimeter scales rather than directly mapping spatial organization. Scanning probes should be well-suited to study the spatial structure of these states, but high mobility 2DESs are found at buried semiconductor interfaces, beyond the reach of conventional scanning tunneling microscopy. Scanning techniques based on electrostatic coupling to the 2DES deliver important insights, but generally with resolution limited by the depth of the 2DES. In this letter, we present our progress in developing a technique called “virtual scanning tunneling microscopy” that allows local tunneling into a high mobility 2DES. Using a specially designed bilayer GaAs/AlGaAs heterostructure where the tunnel coupling between two separate 2DESs is tunable via electrostatic gating, combined with a scanning gate, we show that the local tunneling can be controlled with sub-250 nm resolution.

  15. The Galileo scan platform pointing control system - A modern control theoretic viewpoint

    NASA Technical Reports Server (NTRS)

    Sevaston, G. E.; Macala, G. A.; Man, G. K.

    1985-01-01

    The current Galileo scan platform pointing control system (SPPCS) is described, and ways in which modern control concepts could serve to enhance it are considered. Of particular interest are: the multi-variable design model and overall control system architecture, command input filtering, feedback compensator and command input design, stability robustness constraint for both continuous time control systems and for sampled data control systems, and digital implementation of the control system. The proposed approach leads to the design of a system that is similar to current Galileo SPPCS configuration, but promises to be more systematic.

  16. Developing an Environmental Scanning System in an Educational Organization: Lessons Learned. AIR 1990 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Morrison, James L.; Ptaszynski, James G.

    An environmental scanning system was developed by the admissions office of a graduate school of management in a small southeastern university. The school's strategic planning committee felt that it would be beneficial to acquire information concerning issues, trends, and possible events that might impact upon the school in the future and to…

  17. Biological sample evaluation using a line-scan based SWIR hyperspectral imaging system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new line-scan hyperspectral imaging system was developed to enable short wavelength infrared (SWIR) imagery for biological sample evaluation. Critical sensing components include a SWIR imaging spectrograph and an HgCdTe (MCT) focal plane array detector. To date, agricultural applications of infra...

  18. The Mathematical Model of Image, Generated by Scanning Digital Radiography System

    NASA Astrophysics Data System (ADS)

    Udod, V. A.; Osipov, S. P.; Wang, Yanzhao

    2017-01-01

    The mathematical model of image, generated by scanning digital radiography system is present. This model takes into account the X-ray energy spectrum transformation of the test object and a noise due to the quantum nature of radiation. The calculation results confirm the importance of fluctuations of the absorbed energy of the registered photon for the small size of the scintillation detectors.

  19. Inspection of float glass using a novel retroreflective laser scanning system

    NASA Astrophysics Data System (ADS)

    Holmes, Jonathan D.

    1997-07-01

    Since 1988, Image Automation has marketed a float glass inspection system using a novel retro-reflective laser scanning system. The (patented) instrument scans a laser beam by use of a polygon through the glass onto a retro-reflective screen, and collects the retro-reflected light off the polygon, such that a stationary image of the moving spot on the screen is produced. The spot image is then analyzed for optical effects introduced by defects within the glass, which typically distort and attenuate the scanned laser beam, by use of suitable detectors. The inspection system processing provides output of defect size, shape and severity, to the factory network for use in rejection or sorting of glass plates to the end customer. This paper briefly describes the principles of operation, the system architecture, and limitations to sensitivity and measurement repeatability. New instruments based on the retro-reflective scanning method have recently been developed. The principles and implementation are described. They include: (1) Simultaneous detection of defects within the glass and defects in a mirror coating on the glass surface using polarized light. (2) A novel distortion detector for very dark glass. (3) Measurement of optical quality (flatness/refractive homogeneity) of the glass using a position sensitive detector.

  20. Functions and Requirements for the DST Knuckle Region Ultrasonic Scanning System

    SciTech Connect

    Pardini, Allan F.; Samuel, Todd J.

    2001-01-29

    This document defines the functions and requirements for a ultrasonic scanning system to provide an examination of the knuckle region of Hanford's double shell waste tanks, This document provides the basis for the ultrasonic concept selection, design, fabrication, and deployment methodology.

  1. Three-dimensional body scanning system for apparel mass-customization

    NASA Astrophysics Data System (ADS)

    Xu, Bugao; Huang, Yaxiong; Yu, Weiping; Chen, Tong

    2002-07-01

    Mass customization is a new manufacturing trend in which mass-market products (e.g., apparel) are quickly modified one at a time based on customers' needs. It is an effective competing strategy for maximizing customers' satisfaction and minimizing inventory costs. An automatic body measurement system is essential for apparel mass customization. This paper introduces the development of a body scanning system, body size extraction methods, and body modeling algorithms. The scanning system utilizes the multiline triangulation technique to rapidly acquire surface data on a body, and provides accurate body measurements, many of which are not available with conventional methods. Cubic B-spline curves are used to connect and smooth body curves. From the scanned data, a body form can be constructed using linear Coons surfaces. The body form can be used as a digital model of the body for 3-D garment design and for virtual try-on of a designed garment. This scanning system and its application software enable apparel manufacturers to provide custom design services to consumers seeking personal-fit garments.

  2. A versatile fluorescence lifetime imaging system for scanning large areas with high time and spatial resolution

    NASA Astrophysics Data System (ADS)

    Bernardo, César; Belsley, Michael; de Matos Gomes, Etelvina; Gonçalves, Hugo; Isakov, Dmitry; Liebold, Falk; Pereira, Eduardo; Pires, Vladimiro; Samantilleke, Anura; Vasilevskiy, Mikhail; Schellenberg, Peter

    2014-08-01

    We present a flexible fluorescence lifetime imaging device which can be employed to scan large sample areas with a spatial resolution adjustable from many micrometers down to sub-micrometers and a temporal resolution of 20 picoseconds. Several different applications of the system will be presented including protein microarrays analysis, the scanning of historical samples, evaluation of solar cell surfaces and nanocrystalline organic crystals embedded in electrospun polymeric nanofibers. Energy transfer processes within semiconductor quantum dot superstructures as well as between dye probes and graphene layers were also investigated.

  3. Analysis of a head-mounted display-type multifocus display system using a laser scanning method

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Wook; Kwon, Yong-Moo; Park, Q.-Han; Kim, Sung-Kyu

    2011-03-01

    We developed a head-mounted display (HMD)-type multifocus display system using a laser-scanning method to provide an accommodation effect for viewers. This accomplishment indicates that providing a monocular depth cue is possible through this multifocus system. In the system, the optical path is changed by a scanning action. To provide an accurate accommodation effect for the viewer, the multifocus display system is designed and manufactured in accordance with the geometric analysis of the system's scanning action. Using a video camera as a substitute for the viewer, correct focus adjustment without the scanning action problem is demonstrated. By analyzing the scanning action and experimental results, we are able to illustrate the formation of a viewpoint in an HMD-type multifocus display system using a laser-scanning method. In addition, we demonstrate that the accommodation effect could be provided independent of the viewing condition of the viewer.

  4. Nanoelectrical probing with multiprobe SPM Systems compatible with scanning electron microscopes

    NASA Astrophysics Data System (ADS)

    Lewis, Aaron; Ignatov, Andrey; Taha, Hesham; Zhinoviev, Oleg; Komissar, Anatoly; Krol, Alexander; Lewis, David

    2011-03-01

    A scanning electron microscope compatible platform that permits multiprobe atomic force microscopy based nanoelectrical characterization will be described. To achieve such multiple parameter nanocharacterization with scanning electron microscope compatibility involves a number of innovations both in instrument and probe design. This presentation will focus on how these advances were achieved and the results obtained with such instrumentation on electrical nano-characterization and electrical nano-manipulation. The advances include: 1. Specialized scanners; 2. An ultrasensitive feedback mechanism based on tuning forks with no optical feedback interference that can induce carriers in semiconductor devices; and 3. Unique probes compatible with multiprobe geometries in which the probe tips can be brought into physical contact with one another. Experiments will be described with such systems that will include multiprobe electrical measurements with metal and glass coated coaxial nanowires of platinum. This combination of scanning electron microscopes integrated with multiprobe instrumentation allows for important applications not available today in the field of semiconductor processing technology.

  5. Wide-aperture, line-focused ultrasonic material characterization system based on lateral scanning.

    PubMed

    Titov, Sergey; Maev, Roman; Bogatchenkov, Alexey

    2003-08-01

    We present a new wide-aperture, line-focused ultrasonic material characterization system. The foci of the transmitting and receiving transducers are located in the specimen-immersion liquid interface; and the output voltage V(x,t) of the system is recorded as a function of the lateral position of the receiving transducer. The two-dimensional spectrum of V(x, t) can be expressed as a product of the transfer function of the system and the reflectance function of the interface. In comparison with a system based on scanning in the z direction, the angular resolution of the proposed technique increases with decreasing angle of incidence. There are no geometrical restrictions on the length of the recorded spatial data and the angle of incidence in the case of lateral scanning. The temperature coefficient of the measurement error is low because of the constancy of the propagation distance of ultrasound in the immersion fluid during data acquisition.

  6. A Laser Line Auto-Scanning System for Underwater 3D Reconstruction.

    PubMed

    Chi, Shukai; Xie, Zexiao; Chen, Wenzhu

    2016-09-20

    In this study, a laser line auto-scanning system was designed to perform underwater close-range 3D reconstructions with high accuracy and resolution. The system changes the laser plane direction with a galvanometer to perform automatic scanning and obtain continuous laser strips for underwater 3D reconstruction. The system parameters were calibrated with the homography constraints between the target plane and image plane. A cost function was defined to optimize the galvanometer's rotating axis equation. Compensation was carried out for the refraction of the incident and emitted light at the interface. The accuracy and the spatial measurement capability of the system were tested and analyzed with standard balls under laboratory underwater conditions, and the 3D surface reconstruction for a sealing cover of an underwater instrument was proved to be satisfactory.

  7. A Laser Line Auto-Scanning System for Underwater 3D Reconstruction

    PubMed Central

    Chi, Shukai; Xie, Zexiao; Chen, Wenzhu

    2016-01-01

    In this study, a laser line auto-scanning system was designed to perform underwater close-range 3D reconstructions with high accuracy and resolution. The system changes the laser plane direction with a galvanometer to perform automatic scanning and obtain continuous laser strips for underwater 3D reconstruction. The system parameters were calibrated with the homography constraints between the target plane and image plane. A cost function was defined to optimize the galvanometer’s rotating axis equation. Compensation was carried out for the refraction of the incident and emitted light at the interface. The accuracy and the spatial measurement capability of the system were tested and analyzed with standard balls under laboratory underwater conditions, and the 3D surface reconstruction for a sealing cover of an underwater instrument was proved to be satisfactory. PMID:27657074

  8. System and method for chromatography and electrophoresis using circular optical scanning

    DOEpatents

    Balch, Joseph W.; Brewer, Laurence R.; Davidson, James C.; Kimbrough, Joseph R.

    2001-01-01

    A system and method is disclosed for chromatography and electrophoresis using circular optical scanning. One or more rectangular microchannel plates or radial microchannel plates has a set of analysis channels for insertion of molecular samples. One or more scanning devices repeatedly pass over the analysis channels in one direction at a predetermined rotational velocity and with a predetermined rotational radius. The rotational radius may be dynamically varied so as to monitor the molecular sample at various positions along a analysis channel. Sample loading robots may also be used to input molecular samples into the analysis channels. Radial microchannel plates are built from a substrate whose analysis channels are disposed at a non-parallel angle with respect to each other. A first step in the method accesses either a rectangular or radial microchannel plate, having a set of analysis channels, and second step passes a scanning device repeatedly in one direction over the analysis channels. As a third step, the scanning device is passed over the analysis channels at dynamically varying distances from a centerpoint of the scanning device. As a fourth step, molecular samples are loaded into the analysis channels with a robot.

  9. A non-contact time-domain scanning brain imaging system: first in-vivo results

    NASA Astrophysics Data System (ADS)

    Mazurenka, M.; Di Sieno, L.; Boso, G.; Contini, D.; Pifferi, A.; Dalla Mora, A.; Tosi, A.; Wabnitz, H.; Macdonald, R.

    2013-06-01

    We present results of first in-vivo tests of an optical non-contact scanning imaging system, intended to study oxidative metabolism related processes in biological tissue by means of time-resolved near-infrared spectroscopy. Our method is a novel realization of the short source-detector separation approach and based on a fast-gated single-photon avalanche diode to detect late photons only. The scanning system is built in quasi-confocal configuration and utilizes polarizationsensitive detection. It scans an area of 4×4 cm2, recording images with 32×32 pixels, thus creating a high density of source-detector pairs. To test the system we performed a range of in vivo measurements of hemodynamic changes in several types of biological tissues, i.e. skin (Valsalva maneuver), muscle (venous and arterial occlusions) and brain (motor and cognitive tasks). Task-related changes in hemoglobin concentrations were clearly detected in skin and muscle. The brain activation shows weaker, but yet detectable changes. These changes were localized in pixels near the motor cortex area (C3). However, it was found that even very short hair substantially impairs the measurement. Thus the applicability of the scanner is limited to hairless parts of body. The results of our first in-vivo tests prove the feasibility of non-contact scanning imaging as a first step towards development of a prototype for biological tissue imaging for various medical applications.

  10. Laser-based ultrasonic inspection with a fiber-coupled scanning Cassegrain system.

    PubMed

    McKie, Andrew D W; Addison, Robert C

    2002-12-01

    State-of-the-art integrally stiffened composite materials, manufactured for use in the next generation of commercial and military aircraft, are increasingly being used for structural components such as wings and fuselages. However, the complexity of the manufacturing processes can produce small variations in the shape of integrally stiffened composite structures. Thus, a priori knowledge of the nominal part shape often does not provide sufficient accuracy to allow an automated conventional ultrasonic inspection. In contrast, automated inspections of integrally stiffened structures can be performed using laser-based ultrasound techniques since a priori knowledge of the nominal part shape is adequate to scan the laser beams over the structure. This paper addresses the issues associated with the extension of laser-based ultrasonics to inspections in remote and limited access areas, and describes the implementation of a fiber-based remote and limited access LBU inspection system based upon a Cassegrain scanning and optical collection system. The ability to quickly and directly manipulate flexible low mass optical fibers equipped with specialized endoscopic scanning optics make fiber systems an attractive method for the development of limited and remote access inspection systems. The Cassegrain optical system is described in detail and both numerical and experimental validation of the system operational characteristics are presented.

  11. MULTISPECTRAL LINE-SCAN IMAGING SYSTEM FOR SIMULTANEOUS FLUORESCENCE AND REFLECTANCE MEASUREMENTS OF APPLES: MULTITASK APPLE INSPECTION SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this methodology paper, a recently developed line-scan imaging system, capable of simultaneously acquiring a combination of multispectral reflectance and fluorescence from fast moving objects, is presented. The system can potentially provide multitask inspections for quality and safety attribute...

  12. Quantitative assessment of damage growth in graphite epoxy laminates by acousto-ultrasonic measurements

    NASA Technical Reports Server (NTRS)

    Talreja, R.; Govada, A.; Henneke, E. G., II

    1984-01-01

    The acoustoultrasonic NDT method proposed by Vary (1976, 1978) for composite laminate damage growth quantitative assessment can both respond to the development of damage states and furnish quantitative parameters that monitor this damage development. Attention is presently given to data obtained for the case of quasi-static loading and fatigue testing of graphite-epoxy laminates. The shape parameters of the power spectral density for the ultrasonic signals correlate well with such other indications of damage development as stiffness degradation.

  13. Quasi-4D laser diagnostics using an acousto-optic deflector scanning system

    NASA Astrophysics Data System (ADS)

    Li, Tao; Pareja, Jhon; Becker, Lukas; Heddrich, Wolfgang; Dreizler, Andreas; Böhm, Benjamin

    2017-03-01

    In this paper, a novel scanning system for laser diagnostics was developed and characterized. The system is based on the acousto-optic deflection of a high-speed pulsed laser. Results showed that quasi-volumetric laser illumination with high precision and accuracy can be achieved with a simplified and flexible optical setup. The feasibility of the method for performing high-speed quasi-4D laser diagnostics was demonstrated by the tomographic visualization of a lifted turbulent jet flame using Mie-scattering and multi-plane particle image velocimetry measurements of a turbulent non-reactive mixing case. Three-dimensional flame and flow structures can be detected and tracked with this new scanning system.

  14. Automatic tool alignment in a backscatter X-ray scanning system

    SciTech Connect

    Garretson, Justin; Hobart, Clinton G.; Gladwell, Thomas S.; Monda, Mark J.

    2015-11-17

    Technologies pertaining to backscatter x-ray scanning systems are described herein. The backscatter x-ray scanning system includes an x-ray source, which directs collimated x-rays along a plurality of output vectors towards a target. A detector detects diffusely reflected x-rays subsequent to respective collimated x-rays impacting the target, and outputs signals indicative of parameters of the detected x-rays. An image processing system generates an x-ray image based upon parameters of the detected x-rays, wherein each pixel in the image corresponds to a respective output vector. A user selects a particular portion of the image, and a medical device is positioned such that its directional axis is coincident with the output vector corresponding to at least one pixel in the portion of the image.

  15. OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS

    SciTech Connect

    Schmidt, K. F. Jr.; Little, J. R. Jr.; Ellingson, W. A.; Green, W.

    2010-02-22

    The projected microwave energy pattern, wave guide geometry, positioning methods and process variables have been optimized for use of a portable, non-contact, lap-top computer-controlled microwave interference scanning system on multi-layered dielectric materials. The system can be used in situ with one-sided access and has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper presents the details of the system, the optimization steps and discusses results obtained.

  16. MRT letter: An extended scanning probe microscopy system for macroscopic topography imaging.

    PubMed

    Fu, Ji; Li, Faxin

    2014-10-01

    Enlightened by the principle of scanning probe microscopy or atomic force microscope (AFM), we proposed a novel surface topography imaging system based on the scanning of a piezoelectric unimorph cantilever. The height of sample surface can be obtained by recording the cantilever's strain using an ultra-sensitive strain gauge and the Z-axis movement is realized by electric bending of the cantilever. This system can be operated in the way similar to the contact mode in AFM, with the practical height detection resolution better than 100 nm. Imaging of the inner surface of a steel tube and on a transparent wing of a honey bee were conducted and the obtained results showed that this proposed system is a very promising solution for in situ topography mapping.

  17. Automatic tool alignment in a backscatter x-ray scanning system

    DOEpatents

    Garretson, Justin; Hobart, Clinton G.; Gladwell, Thomas S.; Monda, Mark J.

    2015-06-16

    Technologies pertaining to backscatter x-ray scanning systems are described herein. The backscatter x-ray scanning system includes an x-ray source, which directs collimated x-rays along a plurality of output vectors towards a target. A detector detects diffusely reflected x-rays subsequent to respective collimated x-rays impacting the target, and outputs signals indicative of parameters of the detected x-rays. An image processing system generates an x-ray image based upon parameters of the detected x-rays, wherein each pixel in the image corresponds to a respective output vector. A user selects a particular portion of the image, and a tool is positioned such that its directional axis is coincident with the output vector corresponding to at least one pixel in the portion of the image.

  18. Volumetric display system based on three-dimensional scanning of inclined optical image.

    PubMed

    Miyazaki, Daisuke; Shiba, Kensuke; Sotsuka, Koji; Matsushita, Kenji

    2006-12-25

    A volumetric display system based on three-dimensional (3D) scanning of an inclined image is reported. An optical image of a two-dimensional (2D) display, which is a vector-scan display monitor placed obliquely in an optical imaging system, is moved laterally by a galvanometric mirror scanner. Inclined cross-sectional images of a 3D object are displayed on the 2D display in accordance with the position of the image plane to form a 3D image. Three-dimensional images formed by this display system satisfy all the criteria for stereoscopic vision because they are real images formed in a 3D space. Experimental results of volumetric imaging from computed-tomography images and 3D animated images are presented.

  19. Beam characteristics in two different proton uniform scanning systems: A side-by-side comparison

    SciTech Connect

    Nichiporov, Dmitri; Hsi Wen; Farr, Jonathan

    2012-05-15

    Purpose: To compare clinically relevant dosimetric characteristics of proton therapy fields produced by two uniform scanning systems that have a number of similar hardware components but employ different techniques of beam spreading. Methods: This work compares two technologically distinct systems implementing a method of uniform scanning and layer stacking that has been developed independently at Indiana University (IU) and by Ion Beam Applications, S. A. (IBA). Clinically relevant dosimetric characteristics of fields produced by these systems are studied, such as beam range control, peak-to-entrance ratio (PER), lateral penumbra, field flatness, effective source position, precision of dose delivery at different gantry angles, etc. Results: Under comparable conditions, both systems controlled beam range with an accuracy of 0.5 mm and a precision of 0.1 mm. Compared to IBA, the IU system produced pristine peaks with a slightly higher PER (3.23 and 3.45, respectively) and smaller, symmetrical, lateral in-air penumbra of 1 mm compared to about 1.9/2.4 mm in the inplane/crossplane (IP/CP) directions for IBA. Large field flatness results in the IP/CP directions were similar: 3.0/2.4% for IU and 2.9/2.4% for IBA. The IU system featured a longer virtual source-to-isocenter position, which was the same for the IP and CP directions (237 cm), as opposed to 212/192 cm (IP/CP) for IBA. Dose delivery precision at different gantry angles was higher in the IBA system (0.5%) than in the IU system (1%). Conclusions: Each of the two uniform scanning systems considered in this work shows some attractive performance characteristics while having other features that can be further improved. Overall, radiation field characteristics of both systems meet their clinical specifications and show comparable results. Most of the differences observed between the two systems are clinically insignificant.

  20. Development and demonstration of table-top synchronized fast-scan femtosecond time-resolved spectroscopy system by single-shot scan photo detector array

    NASA Astrophysics Data System (ADS)

    Yabushita, Atsushi; Kao, Chih-Hsien; Lee, Yu-Hsien; Kobayashi, Takayoshi

    2015-07-01

    Ultrafast dynamics is generally studied by pump-probe method with laser pulse, which scans optical delay by motorized stage step by step. Using ultrashort laser pulse shorter than typical molecular vibration periods, the pump-probe measurement can study both of electronic dynamics and vibration dynamics simultaneously. The probe wavelength dependence of the ultrafast electronic and vibration dynamics (UEVD) helps us to distinguish the signal contributions from the dynamics of the electronic ground state and that of the electronic excited states, which elucidates primary reaction mechanism after photoexcitation. Meanwhile, the measurement time of UEVD spectroscopy takes too long time to be used in realistic application. In our previous work, we have developed multi-channel lock-in amplifying (MLA) detectors to study UEVD at all probe wavelengths simultaneously, and synchronized it with laser and fast-scan delay stage to scan the data in five seconds. It enabled us to study UEVD spectroscopy even for photo-fragile materials. However, the home-made MLA detectors required for the measurement is expensive and massive in size and weight, thus not suitable for general researchers in the field of ultrafast time-resolved spectroscopy. In the present work, we have developed a table-top synchronized fast-scan femtosecond time-resolved spectroscopy system using single shot scan line CCD. This system measures time-resolved trace at all probe wavelengths simultaneously in five seconds. The CCD-based fast-scan time-resolved spectroscopy system enables us to study ultrafast dynamics of various materials even biomaterials, which have been thought to be hard or even impossible to be studied in previous methods.

  1. An experimental evaluation method for the performance of a laser line scanning system with multiple sensors

    NASA Astrophysics Data System (ADS)

    Tian, Qingguo; Yang, Yujie; Zhang, Xiangyu; Ge, Baozhen

    2014-01-01

    Laser line scanning 3D digitising systems have a wide range of applications. Their working performance is mainly determined by the system calibration procedure and is also affected by the working conditions, CCD camera imperfections, and object surface optical characteristics. Therefore, a comprehensive evaluation of working performance is necessary before and during use. This study proposes an experimental method for the performance evaluation of a laser line scanner (LLS) with 8 scanning sensors developed in our laboratory. This method first obtains the dense point clouds of standard parts composed of disks, cylinders, and squares. Next, the single-layer point clouds located in horizontal planes of different heights are fitted using the least squares method to obtain the enclosed contours S. Three parameters, namely, the standard deviation of the distance distribution between points and S, the mean distance of the distance distribution, and the shape feature sizes, are used to evaluate the performance. The proposed method evaluates both the scanner as a whole and each scanning sensor. Using this method, more comprehensive information can be acquired to evaluate the scanner performance. The experimental results show that the absolute dimension size error and relative error are less than 5 mm and 3%, respectively, and the relative shape error is less than 2%; therefore, the evaluated LLS system can meet the requirements for human anthropometry applications. Although each scanning sensor has different random and systematic error, these errors are the function of measurement depth. These conclusions are helpful for the further use of this scanner system and can be utilised to optimise this LLS system further.

  2. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems.

    PubMed

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-05-04

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system's trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach.

  3. Laser cutting of irregular shape object based on stereo vision laser galvanometric scanning system

    NASA Astrophysics Data System (ADS)

    Qi, Li; Zhang, Yixin; Wang, Shun; Tang, Zhiqiang; Yang, Huan; Zhang, Xuping

    2015-05-01

    Irregular shape objects with different 3-dimensional (3D) appearances are difficult to be shaped into customized uniform pattern by current laser machining approaches. A laser galvanometric scanning system (LGS) could be a potential candidate since it can easily achieve path-adjustable laser shaping. However, without knowing the actual 3D topography of the object, the processing result may still suffer from 3D shape distortion. It is desirable to have a versatile auxiliary tool that is capable of generating 3D-adjusted laser processing path by measuring the 3D geometry of those irregular shape objects. This paper proposed the stereo vision laser galvanometric scanning system (SLGS), which takes the advantages of both the stereo vision solution and conventional LGS system. The 3D geometry of the object obtained by the stereo cameras is used to guide the scanning galvanometers for 3D-shape-adjusted laser processing. In order to achieve precise visual-servoed laser fabrication, these two independent components are integrated through a system calibration method using plastic thin film target. The flexibility of SLGS has been experimentally demonstrated by cutting duck feathers for badminton shuttle manufacture.

  4. Benchmarking the Performance of Mobile Laser Scanning Systems Using a Permanent Test Field

    PubMed Central

    Kaartinen, Harri; Hyyppä, Juha; Kukko, Antero; Jaakkola, Anttoni; Hyyppä, Hannu

    2012-01-01

    The performance of various mobile laser scanning systems was tested on an established urban test field. The test was connected to the European Spatial Data Research (EuroSDR) project “Mobile Mapping—Road Environment Mapping Using Mobile Laser Scanning”. Several commercial and research systems collected laser point cloud data on the same test field. The system comparisons focused on planimetric and elevation errors using a filtered digital elevation model, poles, and building corners as the reference objects. The results revealed the high quality of the point clouds generated by all of the tested systems under good GNSS conditions. With all professional systems properly calibrated, the elevation accuracy was better than 3.5 cm up to a range of 35 m. The best system achieved a planimetric accuracy of 2.5 cm over a range of 45 m. The planimetric errors increased as a function of range, but moderately so if the system was properly calibrated. The main focus on mobile laser scanning development in the near future should be on the improvement of the trajectory solution, especially under non-ideal conditions, using both improvements in hardware and software. Test fields are relatively easy to implement in built environments and they are feasible for verifying and comparing the performance of different systems and also for improving system calibration to achieve optimum quality.

  5. Design of a robust SHM system for composite structures

    NASA Astrophysics Data System (ADS)

    Beard, Shawn; Liu, Ching-Chao; Chang, Fu-Kuo

    2007-04-01

    Composites are becoming increasingly popular materials used in a wide range of applications on large-scale structures such as windmill blades, rocket motor cases, and aircraft fuselage and wings. For these large structures, using composites greatly enhances the operation and performance of the application, but also introduces extraordinary inspection challenges that push the limits of traditional NDE in terms of time and cost. Recent advances in Structural Health Monitoring (SHM) technologies offer a promising solution to these inspection challenges. But efficient design methodologies and implementation procedures are needed to ensure the reliability and robustness of SHM technologies for use in real-world applications. This paper introduces the essential elements of the design and implementation process by way of example. State-of-the-art techniques to optimize sensor placement, perform self-diagnostics, compensate for environmental conditions, and generate probability of detection (POD) curves for any application are discussed. The techniques are presented in relation to Acellent's recently developed SmartComposite System that is used to monitor the integrity of large composite structures. The system builds on the active sensor network technology of Acellent that is analogous to a built-in acousto-ultrasonic NDE system. Key features of the system include new miniaturized lightweight hardware, self-diagnostics and adaptive algorithm to automatically compensate for damaged sensors, reliable damage detection under different environmental conditions, and generation of POD curves. This paper will provide an overview of the system and demonstrate its key features.

  6. Temporal subtraction system on torso FDG-PET scans based on statistical image analysis

    NASA Astrophysics Data System (ADS)

    Shimizu, Yusuke; Hara, Takeshi; Fukuoka, Daisuke; Zhou, Xiangrong; Muramatsu, Chisako; Ito, Satoshi; Hakozaki, Kenta; Kumita, Shin-ichiro; Ishihara, Kei-ichi; Katafuchi, Tetsuro; Fujita, Hiroshi

    2013-02-01

    Diagnostic imaging on FDG-PET scans was often used to evaluate chemotherapy results of cancer patients. Radiologists compare the changes of lesions' activities between previous and current examinations for the evaluation. The purpose of this study was to develop a new computer-aided detection (CAD) system with temporal subtraction technique for FDGPET scans and to show the fundamental usefulness based on an observer performance study. Z-score mapping based on statistical image analysis was newly applied to the temporal subtraction technique. The subtraction images can be obtained based on the anatomical standardization results because all of the patients' scans were deformed into standard body shape. An observer study was performed without and with computer outputs to evaluate the usefulness of the scheme by ROC (receiver operating characteristics) analysis. Readers responded as confidence levels on a continuous scale from absolutely no change to definitely change between two examinations. The recognition performance of the computer outputs for the 43 pairs was 96% sensitivity with 31.1 false-positive marks per scan. The average of area-under-the-ROC-curve (AUC) from 4 readers in the observer performance study was increased from 0.85 without computer outputs to 0.90 with computer outputs (p=0.0389, DBM-MRMC). The average of interpretation time was slightly decreased from 42.11 to 40.04 seconds per case (p=0.625, Wilcoxon test). We concluded that the CAD system for torso FDG-PET scans with temporal subtraction technique might improve the diagnostic accuracy of radiologist in cancer therapy evaluation.

  7. Study on the parameters of the scanning system for the 300 keV electron accelerator

    SciTech Connect

    Leo, K. W.; Chulan, R. M. Hashim, S. A.; Baijan, A. H.; Sabri, R. M.; Mohtar, M.; Glam, H.; Lojius, L.; Zahidee, M.; Azman, A.; Zaid, M.

    2016-01-22

    This paper describes the method to identify the magnetic coil parameters of the scanning system. This locally designed low energy electron accelerator with the present energy of 140 keV will be upgraded to 300 keV. In this accelerator, scanning system is required to deflect the energetic electron beam across a titanium foil in vertical and horizontal direction. The excitation current of the magnetic coil is determined by the energy of the electron beam. Therefore, the magnetic coil parameters must be identified to ensure the matching of the beam energy and excitation coil current. As the result, the essential parameters of the effective lengths for X-axis and Y-axis have been found as 0.1198 m and 0.1134 m and the required excitation coil currents which is dependenton the electron beam energies have be identified.

  8. Enabling freehand lateral scanning of optical coherence tomography needle probes with a magnetic tracking system

    PubMed Central

    Yeo, Boon Y.; McLaughlin, Robert A.; Kirk, Rodney W.; Sampson, David D.

    2012-01-01

    We present a high-resolution three-dimensional position tracking method that allows an optical coherence tomography (OCT) needle probe to be scanned laterally by hand, providing the high degree of flexibility and freedom required in clinical usage. The method is based on a magnetic tracking system, which is augmented by cross-correlation-based resampling and a two-stage moving window average algorithm to improve upon the tracker's limited intrinsic spatial resolution, achieving 18 µm RMS position accuracy. A proof-of-principle system was developed, with successful image reconstruction demonstrated on phantoms and on ex vivo human breast tissue validated against histology. This freehand scanning method could contribute toward clinical implementation of OCT needle imaging. PMID:22808429

  9. Study of 3D remote sensing system based on optical scanning holography

    NASA Astrophysics Data System (ADS)

    Zhao, Shihu; Yan, Lei

    2009-06-01

    High-precision and real-time remote sensing imaging system is an important part of remote sensing development. Holography is a method of wave front record and recovery which was presented by Dennis Gabor. As a new kind of holography techniques, Optical scanning holography (OSH) and remote sensing imaging are intended to be combined together and applied in acquisition and interference measurement of remote sensing. The key principles and applicability of OSH are studied and the mathematic relation between Fresnel Zone Plate number, numerical aperture and object distance was deduced, which are proved to be feasible for OSH to apply in large scale remote sensing. At last, a new three-dimensional reflected OSH remote sensing imaging system is designed with the combination of scanning technique to record hologram patterns of large scale remote sensing scenes. This scheme is helpful for expanding OSH technique to remote sensing in future.

  10. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system

    PubMed Central

    Johansson, Johannes D.; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

    2016-01-01

    A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma. PMID:26977357

  11. Implementation of pattern-specific illumination pupil optimization on Step & Scan systems

    NASA Astrophysics Data System (ADS)

    Engelen, Andre; Socha, Robert J.; Hendrickx, Eric; Scheepers, Wieger; Nowak, Frank; Van Dam, Marco; Liebchen, Armin; Faas, Denis A.

    2004-05-01

    Step&Scan systems are pushed towards low k1 applications. Contrast enhancement techniques are crucial for successful implementation of these applications in a production environment. A NA - sigma - illumination mode optimizer and a contrast-based optimization algorithm are implemented in LithoCruiser in order to optimize illumination setting and illumination pupil for a specific repetitive pattern. Calculated illumination pupils have been realized using Diffractive Optical Elements (DOE), which are supported by ASML's AERIAL II illuminator. The qualification of the illumination pupil is done using inline metrology on the ASML Step & Scan system. This paper describes the process of pattern specific illumination optimization for a given mask. Multiple examples will be used to demonstrate the advantage of using non-standard illumination pupils.

  12. [Hyperspectral acquisition system for tongue inspection based on X-Y scanning galvanometer].

    PubMed

    Li, Gang; Zhao, Jing; Lin, Ling; Zhang, Bao-ju

    2011-12-01

    Hyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experiment was made to test the ability of this system. By collecting the hyperspectral information of color pictures with size similar to the tongue, the results of experiment showed that this system can acquire more information of tongue than other methods, and this method can provide a new way for tongue inspection.

  13. Acquisition of quantitative physiological data and computerized image reconstruction using a single scan TV system

    NASA Technical Reports Server (NTRS)

    Baily, N. A.

    1975-01-01

    Single scan operation of television X-ray fluoroscopic systems allow both analog and digital reconstruction of tomographic sections from single plan images. This type of system combined with a minimum of statistical processing showed excellent capabilities for delineating small changes in differential X-ray attenuation. Patient dose reduction is significant when compared to normal operation or film recording. Flat screen, low light level systems were both rugged and light in weight, making them applicable for a variety of special purposes. Three dimensional information was available from the tomographic methods and the recorded data was sufficient when used with appropriate computer display devices to give representative 3D images.

  14. Note: Automated optical focusing on encapsulated devices for scanning light stimulation systems

    SciTech Connect

    Bitzer, L. A.; Benson, N. Schmechel, R.

    2014-08-15

    Recently, a scanning light stimulation system with an automated, adaptive focus correction during the measurement was introduced. Here, its application on encapsulated devices is discussed. This includes the changes an encapsulating optical medium introduces to the focusing process as well as to the subsequent light stimulation measurement. Further, the focusing method is modified to compensate for the influence of refraction and to maintain a minimum beam diameter on the sample surface.

  15. Full-color holographic 3D imaging system using color optical scanning holography

    NASA Astrophysics Data System (ADS)

    Kim, Hayan; Kim, You Seok; Kim, Taegeun

    2016-06-01

    We propose a full-color holographic three-dimensional imaging system that composes a recording stage, a transmission and processing stage and reconstruction stage. In recording stage, color optical scanning holography (OSH) records the complex RGB holograms of an object. In transmission and processing stage, the recorded complex RGB holograms are transmitted to the reconstruction stage after conversion to off-axis RGB holograms. In reconstruction stage, the off-axis RGB holograms are reconstructed optically.

  16. A new form measurement system based on subaperture stitching with a line-scanning interferometer

    NASA Astrophysics Data System (ADS)

    Laubach, Sören; Ehret, Gerd; Riebeling, Jörg; Lehmann, Peter

    2016-12-01

    A new optical form measurement system for almost rotational symmetric surfaces has been set up. It is based on an interferometric line sensor applying sinusoidal path length modulation in combination with a movement system. With this system, ring-shaped subapertures of the specimens are measured. The system is especially suitable for measuring spheres and aspheres with a broad range of radii (r>50 mm). The individual subapertures are stitched together to yield the full 3D topography. Because the rotation of the specimen by more than 360° has to yield the same results, inherent consistency tests are possible. Example measurements of a sphere are shown and discussed. Reproducibility measurements for one ring scan performed with the system show a standard deviation of 14 nm. The system can be set up at a moderate price as off-the-shelf mechanical and optoelectronic devices can be used. Future improvements of the system are discussed.

  17. Dynamic deformation inspection of a human arm by using a line-scan imaging system

    NASA Astrophysics Data System (ADS)

    Hu, Eryi

    2009-11-01

    A line-scan imaging system is used in the dynamic deformation measurement of a human arm when the muscle is contracting and relaxing. The measurement principle is based on the projection grating profilometry, and the measuring system is consisted of a line-scan CCD camera, a projector, optical lens and a personal computer. The detected human arm is put upon a reference plane, and a sinusoidal grating is projected onto the object surface and reference plane at an incidence angle, respectively. The deformed fringe pattern in the same line of the dynamic detected arm is captured by the line-scan CCD camera with free trigger model, and the deformed fringe pattern is recorded in the personal computer for processing. A fast Fourier transform combining with a filtering and spectrum shifting method is used to extract the phase information caused by the profile of the detected object. Thus, the object surface profile can be obtained following the geometric relationship between the fringe deformation and the object surface height. Furthermore, the deformation procedure can be obtained line by line. Some experimental results are presented to prove the feasibility of the inspection system.

  18. Design of a MEMS-based retina scanning system for biometric authentication

    NASA Astrophysics Data System (ADS)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Schelinski, Uwe; Grüger, Heinrich

    2014-05-01

    There is an increasing need for reliable authentication for a number of applications such as e commerce. Common authentication methods based on ownership (ID card) or knowledge factors (password, PIN) are often prone to manipulations and may therefore be not safe enough. Various inherence factor based methods like fingerprint, retinal pattern or voice identifications are considered more secure. Retina scanning in particular offers both low false rejection rate (FRR) and low false acceptance rate (FAR) with about one in a million. Images of the retina with its characteristic pattern of blood vessels can be made with either a fundus camera or laser scanning methods. The present work describes the optical design of a new compact retina laser scanner which is based on MEMS (Micro Electric Mechanical System) technology. The use of a dual axis micro scanning mirror for laser beam deflection enables a more compact and robust design compared to classical systems. The scanner exhibits a full field of view of 10° which corresponds to an area of 4 mm2 on the retinal surface surrounding the optical disc. The system works in the near infrared and is designed for use under ambient light conditions, which implies a pupil diameter of 1.5 mm. Furthermore it features a long eye relief of 30 mm so that it can be conveniently used by persons wearing glasses. The optical design requirements and the optical performance are discussed in terms of spot diagrams and ray fan plots.

  19. Scanning the horizon in a decentralized healthcare system: the Canadian experience.

    PubMed

    Morrison, Andra

    2012-07-01

    Canada has a highly decentralized health care system with 13 provinces and territories delivering health care within their own respective jurisdictions. Decisions regarding which innovative health technologies to adopt are often driven by the unique health care priorities of each jurisdiction's population. To understand these needs, the Canadian Agency for Drugs and Technologies in Health's (CADTH's) Early Awareness Service has expanded its activities. In addition to proactively scanning the horizon for new and emerging health technologies, the Early Awareness Service also scans the horizon for national and jurisdictional health policy issues. This paper looks at CADTH's process for identifying and monitoring policy issues at a national and jurisdictional level. CADTH's Early Awareness Service delivers timely information on emerging health care concerns and technologies that may affect health care finances, facilities, operations, and patient care. The identification of important policy issues can help determine which new and emerging technologies will have the most significant impact on the health care system. The information that CADTH scans can also be used to help decision-makers prepare for potential developments and events that may have an impact on health care systems. By improving its capability to identify and share policy issues across and within jurisdictions, CADTH is better situated to provide information that can be used by policy-makers to help them plan and anticipate for the introduction of new technologies and future developments affecting the unique health care needs of their jurisdictions.

  20. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems

    PubMed Central

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-01-01

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system’s trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach. PMID:25946627

  1. a Low Budget Mobile Laser Scanning Solution Using on Board Sensors and Field Bus Systems of TODAY'S Consumer Automobiles

    NASA Astrophysics Data System (ADS)

    Vock, D. M. M.; Jungmichel, M.

    2011-09-01

    Mobile laser scanning systems (MLS) offer a great potential for acquiring detailed point cloud data of urban and suburban surroundings with minimum effort. In this paper a new solution for MLSs is presented, requiring solely a combination of a profile laser scanning device and systems that are included in today's serialized end consumer vehicles. While today's mobile laser scan systems require different and expensive additional hardware that needs to be mounted onto the vehicle, the devices included within vehicle electronics offer good alternatives without additional costs.The actual scan consists of a continuous profile scan together with information gathered from on-board sensor modules. In a post- processing step, the sensor data is used to reconstruct the car's trajectory for the period of the scan and, based on this information, the track of the scan device for every measured laser pixel. Synchronization of pixel data and vehicle movement is realized via a timestamp signal which is transmitted to the car's field bus system and the scan device. To generate the final point cloud scenario, the trajectory is interpolated for every single scan point and used to convert its local position within the profile into the global coordinate system (Fig.1, Left).

  2. Detection Of Multilayer Cavities By Employing RC-DTH Air Hammer System And Cavity Auto Scanning Laser System

    NASA Astrophysics Data System (ADS)

    Luo, Yongjiang; Li, Lijia; Peng, Jianming; Yin, Kun; Li, Peng; Gan, Xin; Zhao, Letao; Su, Wei

    2015-12-01

    The subterranean cavities are seriously threatened to construction and mining safety, and it's important to obtain the exact localization and dimensions of subterranean cavities for the planning of geotechnical and mining activities. Geophysical investigation is an alternative method for cavity detection, but it usually failed for the uncertainly solution of information and data obtained by Geophysical methods. Drilling is considered as the most accurate method for cavity detection. However, the conventional drilling methods can only be used for single cavity detection, and there is no effective solution for multilayer cavities detection have been reported. In this paper, a reverse circulation (RC) down-the-hole (DTH) air hammer system with a special structured drill bit is built and a cavity auto scanning laser system based on laser range finding technique was employed to confirm the localization and dimensions of the cavities. This RC-DTH air hammer system allows drilling through the upper cavities and putting the cavity auto scanning laser system into the cavity area through the central passage of the drill tools to protect the detection system from collapsing of borehole wall. The RC-DTH air hammer system was built, and field tests were conducted in Lanxian County Iron Ore District, which is located in Lv Liang city of Shan Xi province, the northwest of china. Field tests show that employing the RC-DTH air hammer system assisted by the cavity auto scanning laser system is an efficiency method to detect multilayer cavities.

  3. The CNAO dose delivery system for modulated scanning ion beam radiotherapy

    SciTech Connect

    Giordanengo, S.; Marchetto, F.; Garella, M. A.; Donetti, M.; Bourhaleb, F.; Monaco, V.; Hosseini, M. A.; Peroni, C.; Sacchi, R.; Cirio, R.; Ciocca, M.; Mirandola, A.

    2015-01-15

    Purpose: This paper describes the system for the dose delivery currently used at the Centro Nazionale di Adroterapia Oncologica (CNAO) for ion beam modulated scanning radiotherapy. Methods: CNAO Foundation, Istituto Nazionale di Fisica Nucleare and University of Torino have designed, built, and commissioned a dose delivery system (DDS) to monitor and guide ion beams accelerated by a dedicated synchrotron and to distribute the dose with a full 3D scanning technique. Protons and carbon ions are provided for a wide range of energies in order to cover a sizable span of treatment depths. The target volume, segmented in several layers orthogonally to the beam direction, is irradiated by thousands of pencil beams which must be steered and held to the prescribed positions until the prescribed number of particles has been delivered. For the CNAO beam lines, these operations are performed by the DDS. The main components of this system are two independent beam monitoring detectors, called BOX1 and BOX2, interfaced with two control systems performing the tasks of real-time fast and slow control, and connected to the scanning magnets and the beam chopper. As a reaction to any condition leading to a potential hazard, a DDS interlock signal is sent to the patient interlock system which immediately stops the irradiation. The essential tasks and operations performed by the DDS are described following the data flow from the treatment planning system through the end of the treatment delivery. Results: The ability of the DDS to guarantee a safe and accurate treatment was validated during the commissioning phase by means of checks of the charge collection efficiency, gain uniformity of the chambers, and 2D dose distribution homogeneity and stability. A high level of reliability and robustness has been proven by three years of system activity needing rarely more than regular maintenance and working with 100% uptime. Four identical and independent DDS devices have been tested showing

  4. Design and Development of a Scanning Airborne Direct Detection Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Schwemmer, Geary; Hardesty, Michael; Brewer, Alan; Wilkerson, Thomas; Atlas, Robert; Sirota, Marcos; Lindemann, Scott

    2006-01-01

    In the fall of 2005 we began developing an airborne scanning direct detection molecular Doppler lidar. The instrument is being built as part of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE), a three year project selected by the NASA Earth Sun Technology Office under the Instrument Incubator Program. The TWiLiTE project is a collaboration involving scientists and engineers from NASA Goddard Space Flight Center, NOAA ESRL, Utah State University Space Dynamics Lab, Michigan Aerospace Corporation and Sigma Space Corporation. The TWiLiTE instrument will leverage significant research and development investments made by NASA Goddard and it's partners in the past several years in key lidar technologies and sub-systems (lasers, telescopes, scanning systems, detectors and receivers) required to enable spaceborne global wind lidar measurement. These sub-systems will be integrated into a complete molecular direct detection Doppler wind lidar system designed for autonomous operation on a high altitude aircraft, such as the NASA WB57. The WB57 flies at an altitude of 18 km and from this vantage point the nadir viewing Doppler lidar will be able to profile winds through the full troposphere. The TWiLiTE integrated airborne Doppler lidar instrument will be the first demonstration of a airborne scanning direct detection Doppler lidar and will serve as a critical milestone on the path to a future spaceborne tropospheric wind system. In addition to being a technology testbed for space based tropospheric wind lidar, when completed the TWiLiTE high altitude airborne lidar will be used for studying mesoscale dynamics and storm research (e.g. winter storms, hurricanes) and could be used for calibration and validation of satellite based wind systems such as ESA's Aeolus Atmospheric Dynamics Mission. The TWiLiTE Doppler lidar will have the capability to profile winds in clear air from the aircraft altitude of 18 km to the surface with 250 m vertical resolution and < 2mls

  5. Clinical characterization of a proton beam continuous uniform scanning system with dose layer stacking

    SciTech Connect

    Farr, J. B.; Mascia, A. E.; Hsi, W.-C.; Allgower, C. E.; Jesseph, F.; Schreuder, A. N.; Wolanski, M.; Nichiporov, D. F.; Anferov, V.

    2008-11-15

    A proton beam delivery system on a gantry with continuous uniform scanning and dose layer stacking at the Midwest Proton Radiotherapy Institute has been commissioned and accepted for clinical use. This paper was motivated by a lack of guidance on the testing and characterization for clinical uniform scanning systems. As such, it describes how these tasks were performed with a uniform scanning beam delivery system. This paper reports the methods used and important dosimetric characteristics of radiation fields produced by the system. The commissioning data include the transverse and longitudinal dose distributions, penumbra, and absolute dose values. Using a 208 MeV cyclotron's proton beam, the system provides field sizes up to 20 and 30 cm in diameter for proton ranges in water up to 27 and 20 cm, respectively. The dose layer stacking method allows for the flexible construction of spread-out Bragg peaks with uniform modulation of up to 15 cm in water, at typical dose rates of 1-3 Gy/min. For measuring relative dose distributions, multielement ion chamber arrays, small-volume ion chambers, and radiographic films were employed. Measurements during the clinical commissioning of the system have shown that the lateral and longitudinal dose uniformity of 2.5% or better can be achieved for all clinically important field sizes and ranges. The measured transverse penumbra widths offer a slight improvement in comparison to those achieved with a double scattering beam spreading technique at the facility. Absolute dose measurements were done using calibrated ion chambers, thermoluminescent and alanine detectors. Dose intercomparisons conducted using various types of detectors traceable to a national standards laboratory indicate that the measured dosimetry data agree with each other within 5%.

  6. Probe Scanning Support System by a Parallel Mechanism for Robotic Echography

    NASA Astrophysics Data System (ADS)

    Aoki, Yusuke; Kaneko, Kenta; Oyamada, Masami; Takachi, Yuuki; Masuda, Kohji

    We propose a probe scanning support system based on force/visual servoing control for robotic echography. First, we have designed and formulated its inverse kinematics the construction of mechanism. Next, we have developed a scanning method of the ultrasound probe on body surface to construct visual servo system based on acquired echogram by the standalone medical robot to move the ultrasound probe on patient abdomen in three-dimension. The visual servo system detects local change of brightness in time series echogram, which is stabilized the position of the probe by conventional force servo system in the robot, to compensate not only periodical respiration motion but also body motion. Then we integrated control method of the visual servo with the force servo as a hybrid control in both of position and force. To confirm the ability to apply for actual abdomen, we experimented the total system to follow the gallbladder as a moving target to keep its position in the echogram by minimizing variation of reaction force on abdomen. As the result, the system has a potential to be applied to automatic detection of human internal organ.

  7. Decision model in the laser scanning system for pavement crack detection

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoming; Huang, Jianping; Liu, Wanyu

    2011-12-01

    Pavement crack detection plays an important role in the pavement maintaining and management. Recently, the laser scanning technique for pavement crack detection becomes more and more popular due to its ability of discriminating dark areas, which are not caused by pavement distress such as tire marks, oil spills, and shadows. However, this technique still bears some errors for pavement crack recognition errors, thus in the present work, the factors contributed to these errors in laser scanning system are first analyzed, and then a decision model for the laser scanning pavement crack detection system based on the hypothesis test is proposed. Experimental analyses and results show that this model not only allows us to build the relationship between the contribution factors and crack detection accuracy and to provide the criteria to compare the detection accuracy for the different roads, but also can be used to judge whether the crack exists with a reasonable number of deformed light stripes. Therefore, the proposed decision model can provide guidance on the pavement crack detection and has a practical value.

  8. Application of information theory to the design of line-scan imaging systems

    NASA Technical Reports Server (NTRS)

    Huck, F. O.; Park, S. K.; Halyo, N.; Stallman, S.

    1981-01-01

    Information theory is used to formulate a single figure of merit for assessing the performance of line scan imaging systems as a function of their spatial response (point spread function or modulation transfer function), sensitivity, sampling and quantization intervals, and the statistical properties of a random radiance field. Computational results for the information density and efficiency (i.e., the ratio of information density to data density) are intuitively satisfying and compare well with experimental and theoretical results obtained by earlier investigators concerned with the performance of TV systems.

  9. Thermal characterization of starch-water system by photopyroelectric technique and adiabatic scanning calorimetry

    NASA Astrophysics Data System (ADS)

    Cruz-Orea, A.; Bentefour, E. H.; Jamée, P.; Chirtoc, M.; Glorieux, C.; Pitsi, G.; Thoen, J.

    2003-01-01

    Starch is one of the most important carbohydrate sources in human nutrition. For the thermal analysis of starch, techniques such as differential scanning calorimetry have been extensively used. As an alternative, we have applied a photopyroelectric (PPE) configuration and adiabatic scanning calorimetry (ASC) to study the thermal properties of starch-water systems. For this study we used nixtamalized corn flour and potato starch with different quantities of distilled water, in order to obtain samples with different moisture content. By using PPE and ASC methods we have measured, for each technique separately, the heat capacity by unit volume (ρcp) at room temperature for a corn flour sample at 90% moisture. The obtained values agree within experimental uncertainty. By using these techniques we also studied the thermal behavior of potato starch, at 80% moisture, in the temperature range where phase transitions occur. In this case the PPE signal phase could be used as a sensitive and versatile monitor for phase transitions.

  10. Aberration analysis based on pinhole-z-scan method near the focal point of refractive systems

    NASA Astrophysics Data System (ADS)

    Castro-Marín, Pablo; Garduño-Mejía, Jesús; Rosete-Aguilar, Martha; Bruce, Neil C.; Reid, Derryck T.; Farrell, C.; Sandoval-Romero, Gabriel E.

    2016-09-01

    In this work we present a method used to study the spherical and chromatic aberrations contribution near the focal point of a refractive optical system. The actual focal position is measured by scanning a pinhole attached on the front of a power detector, which are scanned along the optical axis using a motorized stage with 1 μm resolution. Spherical aberration contribution was analyzed by changing the pupil aperture, by modifying the size of the input iris diaphragm and for each case, measuring the actual laser power vs the detector position. Chromatic aberration was analyzed by performing the same procedure but in this case we used an ultra-broad-band femtosecond laser. The results between ML and CW operation were compare. Experimental results are presented.

  11. Optimizing scan parameters for antibody microarray experiments: accelerating robust systems diagnostics for life sciences.

    PubMed

    Gu, Qiang; Sivanandam, Thamil Mani

    2014-06-01

    Microarray experiments are a centerpiece of postgenomics life sciences and the current efforts to develop systems diagnostics for personalized medicine. The majority of antibody microarray experiments are fluorescence-based, which utilizes a scanner to convert target signals into image files for subsequent quantification. Certain scan parameters such as the laser power and photomultiplier tube gain (PMT) can influence the readout of fluorescent intensities and thus may affect data quantitation. To date, however, there is no consensus of how to determine the optimal settings of microarray scanners. Here we show that different settings of the laser power and PMT not only affect the signal intensities but also the accuracy of antibody microarray experiments. More importantly, we demonstrate an experimental approach using two fluorescent dyes to determine optimal settings of scan parameters for microarray experiments. These measures provide added quality control of microarray experiments, and thus help to improve the accuracy of quantitative outcome in microarray experiments in the above contexts.

  12. Foveated scanning: dynamic monodimensional enlargement of resolved field of view in lenses of scanner systems.

    PubMed

    Javaherian, Farhang; Rashidian, Bizhan

    2016-09-10

    An inconsistency between the circular symmetric geometry of conventional optical imagers and the geometry of long linear sensors used in today's line-scan cameras results in suboptimal separate design of optics and electronics of scanner systems. Based on the method of foveated optical imaging, a technique named foveated scanning (FS) is proposed in this paper. The FS technique is employed to enlarge the one-dimensional resolved field of view (RFOV) of conventional lenses and permits optimized performance on a line-of-interest in the image plane where the optoelectronic sensor is located. The achieved enlargement of RFOV is verified on a proof-of-concept basic telephoto lens. Both modulation transfer function analysis and the imaging simulation of a standard target have been performed. Results show a twofold increase in RFOV by this technique.

  13. Novel scanning procedure enabling the vectorization of entire rhizotron-grown root systems

    PubMed Central

    2013-01-01

    This paper presents an original spit-and-combine imaging procedure that enables the complete vectorization of complex root systems grown in rhizotrons. The general principle of the method is to (1) separate the root system into a small number of large pieces to reduce root overlap, (2) scan these pieces one by one, (3) analyze separate images with a root tracing software and (4) combine all tracings into a single vectorized root system. This method generates a rich dataset containing morphological, topological and geometrical information of entire root systems grown in rhizotrons. The utility of the method is illustrated with a detailed architectural analysis of a 20-day old maize root system, coupled with a spatial analysis of water uptake patterns. PMID:23286457

  14. Acquisition of quantitative physiological data and computerized image reconstruction using a single scan TV system

    NASA Technical Reports Server (NTRS)

    Baily, N. A.

    1976-01-01

    A single-scan radiography system has been interfaced to a minicomputer, and the combined system has been used with a variety of fluoroscopic systems and image intensifiers available in clinical facilities. The system's response range is analyzed, and several applications are described. These include determination of the gray scale for typical X-ray-fluoroscopic-television chains, measurement of gallstone volume in patients, localization of markers or other small anatomical features, determinations of organ areas and volumes, computer reconstruction of tomographic sections of organs in motion, and computer reconstruction of transverse axial body sections from fluoroscopic images. It is concluded that this type of system combined with a minimum of statistical processing shows excellent capabilities for delineating small changes in differential X-ray attenuation.

  15. Design of the scanning mode coated glass color difference online detection system

    NASA Astrophysics Data System (ADS)

    Bi, Weihong; Zhang, Yu; Wang, Dajiang; Zhang, Baojun; Fu, Guangwei

    2008-03-01

    A design of scanning mode coated glass color difference online detection system was introduced. The system consisted of color difference data acquirement part and orbit control part. The function of the color difference data acquirement part was to acquire glass spectral reflectance and then processed them to get the color difference value. Using fiber for light guiding, the reflected light from surface of glass was transmitted into light division part, and the dispersive light was imaged on linear CCD, and then the output signals from the CCD was sampled pixel by pixel, and the spectral reflectance of coated glass was obtained finally. Then, the acquired spectral reflectance signals was sent to industrial personal computer through USB interface, using standard color space and color difference formula nominated by International Commission on Illumination (CIE) in 1976 to process these signals, and the reflected color parameter and color difference of coated glass was gained in the end. The function of the orbit control part was to move the detection probe by way of transverse scanning mode above the glass strip, and control the measuring start-stop time of the color difference data acquirement part at the same time. The color difference data acquirement part of the system was put on the orbit which is after annealing area in coated glass production line, and the protected fiber probe was placed on slide of the orbit. Using single chip microcomputer to control transmission mechanism of the slide, which made the slide move by way of transverse scanning mode on the glass strip, meanwhile, the color difference data acquirement part of the system was also controlled by the single chip microcomputer, and it made the acquirement part measure color difference data when the probe reached the needed working speed and required place on the glass strip. The scanning mode coated glass color difference online detection system can measure color parameter and color difference of

  16. Design and implementation of an inexpensive LIDAR scanning system with applications in archaeology

    NASA Astrophysics Data System (ADS)

    Willis, Andrew; Sui, Yunfeng; Ringle, William; Galor, Katherina

    2009-01-01

    This paper describes the development of a system and associated software capable of capturing 3D LIDAR data from surfaces up to 20m from the sensor. The chief concern of this initial system is to minimize cost which, for this initial system, is approximately $10.5k (USD). Secondary considerations for the system include portability, robustness, and size. The system hardware consists of two motors and a single-point sensor, capable of measuring the range of a single surface point location. The motors redirect the emitted laser along lines nearly equivalent to that specified by a spherical coordinate system generating a spherical range image, r = f ( φ, θ). This article describes the technical aspects of the scanner design which include a bill-of-materials for the scanner components and the mathematical model for the measured 3D point data. The designed system was built in 2007 and has since been used in the field twice: (1) for scanning ruins and underground cisterns within Mayan cities near Merida, Mexico and (2) for scanning the ruins of a Crusader castle at Apollonia-Arsuf, located on the Mediterranean shore near Herzliya, Israel. Using this system in these vastly different environments has provided a number of useful insights or "best practices" on the use of inexpensive LIDAR sensors which are discussed in this paper. We also discuss a measurement model for the generated data and an efficient and easy-to-implement algorithm for polygonizing the measured 3D (x,y, z) data. Specific applications of the developed system to archaeological and anthropological problems are discussed.

  17. Scanning laser optical computed tomography system for large volume 3D dosimetry

    NASA Astrophysics Data System (ADS)

    Dekker, Kurtis H.; Battista, Jerry J.; Jordan, Kevin J.

    2017-04-01

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  18. Scanning laser optical computed tomography system for large volume 3D dosimetry.

    PubMed

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2017-04-07

    Stray light causes artifacts in optical computed tomography (CT) that negatively affect the accuracy of radiation dosimetry in gels or solids. Scatter effects are exacerbated by a large dosimeter volume, which is desirable for direct verification of modern radiotherapy treatment plans such as multiple-isocenter radiosurgery. The goal in this study was to design and characterize an optical CT system that achieves high accuracy primary transmission measurements through effective stray light rejection, while maintaining sufficient scan speed for practical application. We present an optical imaging platform that uses a galvanometer mirror for horizontal scanning, and a translation stage for vertical movement of a laser beam and small area detector for minimal stray light production and acceptance. This is coupled with a custom lens-shaped optical CT aquarium for parallel ray sampling of projections. The scanner images 15 cm diameter, 12 cm height cylindrical volumes at 0.33 mm resolution in approximately 30 min. Attenuation coefficients reconstructed from CT scans agreed with independent cuvette measurements within 2% for both absorbing and scattering solutions as well as small 1.25 cm diameter absorbing phantoms placed within a large, scattering medium that mimics gel. Excellent linearity between the optical CT scanner and the independent measurement was observed for solutions with between 90% and 2% transmission. These results indicate that the scanner should achieve highly accurate dosimetry of large volume dosimeters in a reasonable timeframe for clinical application to radiotherapy dose verification procedures.

  19. Scanning all-fiber-optic endomicroscopy system for 3D nonlinear optical imaging of biological tissues

    PubMed Central

    Wu, Yicong; Leng, Yuxin; Xi, Jiefeng; Li, Xingde

    2009-01-01

    An extremely compact all-fiber-optic scanning endomicroscopy system was developed for two-photon fluorescence (TPF) and second harmonic generation (SHG) imaging of biological samples. A conventional double-clad fiber (DCF) was employed in the endomicroscope for single-mode femtosecond pulse delivery, multimode nonlinear optical signals collection and fast two-dimensional scanning. A single photonic bandgap fiber (PBF) with negative group velocity dispersion at two-photon excitation wavelength (i.e. ~810 nm) was used for pulse prechirping in replacement of a bulky grating/lens-based pulse stretcher. The combined use of DCF and PBF in the endomicroscopy system made the endomicroscope basically a plug-and-play unit. The excellent imaging ability of the extremely compact all-fiber-optic nonlinear optical endomicroscopy system was demonstrated by SHG imaging of rat tail tendon and depth-resolved TPF imaging of epithelial tissues stained with acridine orange. The preliminary results suggested the promising potential of this extremely compact all-fiber-optic endomicroscopy system for real-time assessment of both epithelial and stromal structures in luminal organs. PMID:19434122

  20. Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

    NASA Astrophysics Data System (ADS)

    Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

    2016-04-01

    Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

  1. Scoring systems of quantitative bone scanning in prostate cancer: historical overview, current status and future perspectives.

    PubMed

    Zafeirakis, Athanasios

    2014-01-01

    Whole-body bone scintigraphy using technetium-99m-methylene-diphosphonate ((99m)Tc-MDP) is the most widely used radionuclide imaging modality applied in patients with prostate cancer. With this technique, the choice of methods to estimate the extend of the metastatic disease on the skeletal system includes various different approaches, classified in two main categories: First, the quantitative measurements of tracer uptake, defined either as the percentage of the injected dose of tracer, or as the more complicated plasma clearance techniques and second, the various semi-quantitative scoring systems of the bone scan images. These scoring systems can be based either on visual counting of bone lesions, or on the estimation of a numerical index that expresses the fractional involvement of each bone by tumour, called "Bone Scan Index" (BSI); the latter can be produced either visually (manually) or by the more sophisticated techniques of fully- or semi-automated (computerized) forms. In this review, a brief chronological overview of the aforementioned methods is presented, along with the main advantages, drawbacks and the prognostic implications of each method. There remains, however, the challenge of defining, developing and validating the optimal measurement methodology in order these scoring systems to obtain a wider clinical use.

  2. A line-scan hyperspectral system for high-throughput Raman chemical imaging.

    PubMed

    Qin, Jianwei; Chao, Kuanglin; Kim, Moon S

    2014-01-01

    A line-scan hyperspectral system was developed to enable Raman chemical imaging for large sample areas. A custom-designed 785 nm line laser based on a scanning mirror serves as an excitation source. A 45° dichroic beam splitter reflects the laser light to form a 24 cm × 1 mm excitation line normally incident on the sample surface. Raman signals along the laser line are collected by a detection module consisting of a dispersive imaging spectrograph and a CCD camera. A hypercube is accumulated line by line as a motorized table moves the samples transversely through the laser line. The system covers a Raman shift range of -648.7 to 2889.0 cm(-1) and a 23 cm wide area. An example application for authenticating milk powder is presented to demonstrate the system performance. In 4 min the system acquired a 512 × 110 × 1024 hypercube (56  320 spectra) from four, 47 mm diameter Petri dishes containing four powder samples. Chemical images were created for detecting two adulterants (melamine and dicyandiamide) that had been mixed into the milk powder.

  3. MEMS scanner mirror based system for retina scanning and in eye projection

    NASA Astrophysics Data System (ADS)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Dallmann, Hans-Georg; Schelinski, Uwe; Grüger, Heinrich

    2015-02-01

    Many applications could benefit from miniaturized systems to scan blood vessels behind the retina in the human eye, so called "retina scanning". This reaches from access control to sophisticated security applications and medical devices. High volume systems for consumer applications require low cost and a user friendly operation. For example this includes no need for removal of glasses and self-adjustment, in turn guidance of focus and point of attraction by simultaneous projection for the user. A new system has been designed based on the well-known resonantly driven 2-d scanner mirror of Fraunhofer IPMS. A combined NIR and VIS laser system illuminates the eye through an eye piece designed for an operating distance allowing the use of glasses and granting sufficient field of view. This usability feature was considered to be more important than highest miniaturization. The modulated VIS laser facilitates the projection of an image directly onto the retina. The backscattered light from the continuous NIR laser contains the information of the blood vessels and is detected by a highly sensitive photo diode. A demonstrational setup has been realized including readout and driving electronics. The laser power was adjusted to an eye-secure level. Additional security features were integrated. Test measurements revealed promising results. In a first demonstration application the detection of biometric pattern of the blood vessels was evaluated for issues authentication in.

  4. TU-CD-207-05: A Novel Digital Tomosynthesis System Using Orthogonal Scanning Technique: A Feasibility Study

    SciTech Connect

    Kim, J; Park, C; Kauweloa, K; Chung, Y; Han, Y; Ju, S

    2015-06-15

    Purpose: As an alternative to full tomographic imaging technique such as cone-beam computed tomography (CBCT), there is growing interest to adopt digital tomosynthesis (DTS) for the use of diagnostic as well as therapeutic applications. The aim of this study is to propose a new DTS system using novel orthogonal scanning technique, which can provide superior image quality DTS images compared to the conventional DTS scanning system. Methods: Unlike conventional DTS scanning system, the proposed DTS is reconstructed with two sets of orthogonal patient scans. 1) X-ray projections that are acquired along transverse trajectory and 2) an additional sets of X-ray projections acquired along the vertical direction at the mid angle of the previous transverse scan. To reconstruct DTS, we have used modified filtered backprojection technique to account for the different scanning directions of each projection set. We have evaluated the performance of our method using numerical planning CT data of liver cancer patient and a physical pelvis phantom experiment. The results were compared with conventional DTS techniques with single transverse and vertical scanning. Results: The experiments on both numerical simulation as well as physical experiment showed that the resolution as well as contrast of anatomical structures was much clearer using our method. Specifically, the image quality comparing with transversely scanned DTS showed that the edge and contrast of anatomical structures along Left-Right (LR) directions was comparable however, considerable discrepancy and enhancement could be observed along Superior-Inferior (SI) direction using our method. The opposite was observed when vertically scanned DTS was compared. Conclusion: In this study, we propose a novel DTS system using orthogonal scanning technique. The results indicated that the image quality of our novel DTS system was superior compared to conventional DTS system. This makes our DTS system potentially useful in various

  5. Pharmaceutical applications of confocal laser scanning microscopy: the physical characterisation of pharmaceutical systems.

    PubMed

    Pygall, Samuel R; Whetstone, Joanne; Timmins, Peter; Melia, Colin D

    2007-12-10

    The application of confocal laser scanning microscopy (CLSM) to the physicochemical characterisation of pharmaceutical systems is not as widespread as its application within the field of cell biology. However, methods have been developed to exploit the imaging capabilities of CLSM to study a wide range of pharmaceutical systems, including phase-separated polymers, colloidal systems, microspheres, pellets, tablets, film coatings, hydrophilic matrices, and chromatographic stationary phases. Additionally, methods to measure diffusion in gels, bioadhesives, and for monitoring microenvironmental pH change within dosage forms have been utilised. CLSM has also been used in the study of the physical interaction of dosage forms with biological barriers such as the eye, skin and intestinal epithelia, and in particular, to determine the effectiveness of a plethora of pharmaceutical systems to deliver drugs through these barriers. In the future, there is continuing scope for wider exploitation of existing techniques, and continuing advancements in instrumentation.

  6. SU-E-T-595: Output Factor Calculation for a Uniform Scanning Proton Therapy System

    SciTech Connect

    Hecksel, D; Stauffer, N; DeFillippo, G; Edwards, J; Pankuch, M

    2015-06-15

    Purpose: To develop an analytical model that predicts dose output factors for patient treatment fields in a uniform scanning proton therapy system. Methods: A model to predict output factors for patient specific treatment fields was produced based on the methods developed by Kooy et al. (2003). The Kooy model predicts the output factor based on the ratio of the entrance dose under calibration conditions to that for a given range and modulation corrected for the inverse square effect. Field specific output factors were plotted as a function of a single parameter r, where r = (Range-Modulation)/Modulation. The model targeted user range 1 sub-span 3 through user range 2 sup-span 2 of the IBA uniform scanning proton therapy system. The data set included points measured using the 10 cm and 18 cm snout sizes to eliminate stem effects on the monitor unit chambers. The data was fit using equation 15 from Kooy et al. (2003), and the resulting model was tested against measurements that were not included in the original data set. Results: For the range and sub span investigated, 120 data points were tested against the model prediction. The model predicted the output factor within 2% for 96% of the points tested and within 2.5% for 99% of the points tested. All points were within 3% of the predicted values. Conclusion: Monitor units for patient treatment fields with proton ranges that fall within the tested interval can be predicted using a model based on the methods developed at MGH. With further evaluation, it will be possible to model all user ranges and sub-spans of the IBA system. Further testing is also needed to predict output factors using a 25 cm snout which introduces variable scanning pattern sizes and stem effects on the monitor unit chambers.

  7. Optical-mechanical line-scan imaging process - Its information capacity and efficiency. [satellite multispectral sensing systems application

    NASA Technical Reports Server (NTRS)

    Huck, F. O.; Park, S. K.

    1975-01-01

    Optical-mechanical line-scan techniques have been applied to earth satellite multispectral imaging systems. The capability of the imaging system is generally assessed by its information capacity. An approach based on information theory is developed to formulate the capacity of the line-scan process. Included are the effects of blurring of spatial detail, photosensor noise, aliasing, and quantization. The information efficiency is shown to be dependent on sampling rate, system frequency response shape, SNR, and quantization interval.

  8. A High Precision Scanning Control System For A VUV Fourier Transform Spectrometer

    SciTech Connect

    De Oliveira, N.; Nahon, L.; Polack, F.; Joyeux, D.; Phalippou, D.; Rodier, J. C.; Vervloeet, M.

    2007-01-19

    A VUV Fourier transform spectrometer based on a wavefront division interferometer has been built. Our ultimate goal is to provide a high resolution absorption spectrometer in the 140 - 40 nm range using the new third generation French synchrotron source Soleil as the background continuum. Here, we present the design and latest performance of the instrument scanning control system. It is based on multiple reflections of a monomode, frequency-stabilized HeNe laser between two plane mirrors allowing the required sensitivity on the displacement of the interferometer mobile arm. The experimental results on the sampling precision show an rms error below 5 nm for a travel length of 7.5 mm.

  9. Adsorbate-induced quantum Hall system probed by scanning tunneling spectroscopy combined with transport measurements

    SciTech Connect

    Masutomi, Ryuichi Okamoto, Tohru

    2015-06-22

    An adsorbate-induced quantum Hall system at the cleaved InSb surfaces is investigated in magnetic fields up to 14 T using low-temperature scanning tunneling microscopy and spectroscopy combined with transport measurements. We show that an enhanced Zeeman splitting in the Shubnikov-de Haas oscillations is explained by an exchange enhancement of spin splitting and potential disorder, both of which are obtained from the spatially averaged density of states (DOS). Moreover, the Altshuler–Aronov correlation gap is observed in the spatially averaged DOS at 0 T.

  10. The effectiveness of the jammer signal characteristics on conical-scan systems

    NASA Astrophysics Data System (ADS)

    Şahingil, Mehmet C.; Aslan, Murat Ş.

    2015-05-01

    Being passive systems and due to their proliferation to many regions in the world, the infrared (IR) guided missiles constitute probably the most dangerous threats for the aircraft platforms. Early generation surface-to-air and air-to-air IRguided missiles use reticle-based seekers. One of the IR countermeasure (IRCM) techniques for protecting aircraft platforms against these type of threats is to use a modulated jamming signal. Optimizing the parameters of the modulation is the most important issue for an effective protection. If the required characteristic is not satisfied, jamming may not be successful for protecting the aircraft. There are several parameters to define the jammer signal (modulation) characteristic. Optimizing them requires a good understanding of threat seekers' operating principles. In the present paper, we consider protection of a helicopter platform against conical-scan reticle based seeker systems and investigate the effect of the jammer signal modulation parameters on jamming performance via extensive batch simulations. The simulations are performed in a MATLAB-coded simulator which models reticle-based conical-scan seeker, aircraft radiation, aircraft motion and jammer system on the aircraft. The results show that if the properties of the jammer signal are similar to those of the reticle-modulated signal in the missile, the jamming can be successful. Otherwise, applied jamming may not deceive the threat seeker.

  11. A new adaptive light beam focusing principle for scanning light stimulation systems

    SciTech Connect

    Bitzer, L. A.; Meseth, M.; Benson, N.; Schmechel, R.

    2013-02-15

    In this article a novel principle to achieve optimal focusing conditions or rather the smallest possible beam diameter for scanning light stimulation systems is presented. It is based on the following methodology: First, a reference point on a camera sensor is introduced where optimal focusing conditions are adjusted and the distance between the light focusing optic and the reference point is determined using a laser displacement sensor. In a second step, this displacement sensor is used to map the topography of the sample under investigation. Finally, the actual measurement is conducted, using optimal focusing conditions in each measurement point at the sample surface, that are determined by the height difference between camera sensor and the sample topography. This principle is independent of the measurement values, the optical or electrical properties of the sample, the used light source, or the selected wavelength. Furthermore, the samples can be tilted, rough, bent, or of different surface materials. In the following the principle is implemented using an optical beam induced current system, but basically it can be applied to any other scanning light stimulation system. Measurements to demonstrate its operation are shown, using a polycrystalline silicon solar cell.

  12. Bilateral control-based compensation for rotation in imaging in scan imaging systems

    NASA Astrophysics Data System (ADS)

    Tian, Dapeng; Wang, Yutang; Wang, Fuchao; Zhang, Yupeng

    2015-12-01

    Scan imaging systems rely on the rotation of a mirror to scan an image. The rotation in the resulting image must be compensated to prevent information loss. Satisfactory performance of an imaging system is difficult to achieve when employing the methods of mechanical transmission and unilateral tracking control, especially when the system suffers from nonlinear factors, disturbances, and dynamic uncertainties. This paper proposes a compensation method based on bilateral control derived from the field of haptic robots. A two-loop disturbance observer was designed to guarantee that the dynamic characteristics of the motor are close to those of the nominal model. The controllers were designed on the basis of the small gain theorem. Experiments were conducted for a comparison with the traditional unilateral control-based compensation. The comparison showed a reduction of 99.83% in the L2 norm of error, which validates the method. The proposed method improves the accuracy of compensation for rotation in imaging, and demonstrates that bilateral control has feasibility for application in various fields, including photogrammetry.

  13. Historical review and future trends of scanning optical systems for laser-beam printers

    NASA Astrophysics Data System (ADS)

    Minoura, Kazuo

    1993-12-01

    Flying spot scanning technologies providing a constant velocity were presented in 1963 and in 1969, although the concept of `f-0' was not yet explained definitely. After the middle of the 1970s, laser diodes became worthy of notice and a compact-sized laser beam printer was developed. Along with that development, the `f-0 lens' was defined based on the optical design theory in 1979 and also popular-type `f-0 lenses' were developed through the analytical design method. On the other hand, the author and colleagues worked out the best way of enabling metal light deflectors to apply in a popular-type system in 1984; which means the optical system of `deflection error compensation' with the simple composition including a toric lens. The epoch-making optical system raised the productivity of laser beam printers and also has been providing high-definition image printing. As for recent trends, low-priced and compact- sized printers are expanding their share of the market. The author predicts that future laser scanning technologies will be focused in low-priced and process-simplified printers looking closely into high-definition image quality.

  14. Influence of both angle and position error of pentaprism on accuracy of pentaprism scanning system

    NASA Astrophysics Data System (ADS)

    Xu, Kun; Han, Sen; Zhang, Qiyuan; Wu, Quanying

    2014-11-01

    Pentaprism scanning system has been widely used in the measurement of large flat and wavefront, based on its property that the deviated beam will have no motion in the pitch direction. But the manufacturing and position errors of pentaprisms will bring error to the measurement and so a good error analysis method is indispensable. In this paper, we propose a new method of building mathematic models of pentaprism and through which the size and angle errors of a pentaprism can be put into the model as parameters. 4 size parameters are selected to determine the size and 11 angle parameters are selected to determine the angles of a pentaprism. Yaw, Roll and Pitch are used to describe the position error of a pentaprism and an autocollimator. A pentaprism scanning system of wavefront test is simulated by ray tracing using matlab. We design a method of separating the constant from the measurement results which will improve the measurement accuracy and analyze the system error by Monte Carlo method. This method is simple, rapid, accurate and convenient for computer programming.

  15. LIDAR and Ins Fusion in Periods of GPS Outages for Mobile Laser Scanning Mapping Systems

    NASA Astrophysics Data System (ADS)

    Klein, I.; Filin, S.

    2011-09-01

    Mobile laser scanning systems are becoming an increasingly popular means to obtain 3D coverage on a large scale. To perform the mapping, the exact position of the vehicle must be known throughout the trajectory. Exact position is achieved via integration of Global Positioning Systems (GPS) and Inertial Navigation Systems (INS). Yet, in urban environments, cases of complete or even partial GPS outages may occur leaving the navigation solution to rely only on the INS. The INS navigation solution degrades with time as the Inertial Measurement Unit (IMU) measurements contains noise, which permeates into the navigation equations. Degradation of the position determination leads to loss of data in such segments. To circumvent such drift and its effects, we propose fusing INS with lidar data by using building edges. This detection of edges is then translated into position data, which is used as an aiding to the INS. It thereby enables the determination of the vehicle position with a satisfactory level accuracy, sufficient to perform the laser-scanning based mapping in those outage periods.

  16. Integral three-dimensional television using a 2000-scanning-line video system.

    PubMed

    Arai, Jun; Okui, Makoto; Yamashita, Takayuki; Okano, Fumio

    2006-03-10

    We have developed an integral three-dimensional (3-D) television that uses a 2000-scanning-line video system that can shoot and display 3-D color moving images in real time. We had previously developed an integral 3-D television that used a high-definition television system. The new system uses -6 times as many elemental images [160 (horizontal) x 118 (vertical) elemental images] arranged at -1.5 times the density to improve further the picture quality of the reconstructed image. Through comparison an image near the lens array can be reconstructed at -1.9 times the spatial frequency, and the viewing angle is -1.5 times as wide.

  17. Nanoscale Electromechanics of Ferroelectric and Biological Systems: A New Dimension in Scanning Probe Microscopy

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei V.; Rodriguez, Brian J.; Jesse, Stephen; Karapetian, Edgar; Mirman, Boris; Eliseev, Eugene A.; Morozovska, Anna N.

    2007-08-01

    Functionality of biological and inorganic systems ranging from nonvolatile computer memories and microelectromechanical systems to electromotor proteins and cellular membranes is ultimately based on the intricate coupling between electrical and mechanical phenomena. In the past decade, piezoresponse force microscopy (PFM) has been established as a powerful tool for nanoscale imaging, spectroscopy, and manipulation of ferroelectric and piezoelectric materials. Here, we give an overview of the fundamental image formation mechanism in PFM and summarize recent theoretical and technological advances. In particular, we show that the signal formation in PFM is complementary to that in the scanning tunneling microscopy (STM) and atomic force microscopy (AFM) techniques, and we discuss the implications. We also consider the prospect of extending PFM beyond ferroelectric characterization for quantitative probing of electromechanical behavior in molecular and biological systems and high-resolution probing of static and dynamic polarization switching processes in low-dimensional ferroelectric materials and heterostructures.

  18. A flexible Labview{trademark}-based data acquisition and analysis system for scanning microscopy

    SciTech Connect

    Daniel H. Morse; Arlyn J. Antolak; Graham S. Bench; Mark L. Roberts

    1998-10-08

    A new data analysis system has been developed with computer-controlled beam and sample positioning, video sample imaging, multiple large solid angle detectors for x-rays and gamma-rays, and surface barrier detectors for charged particles. The system uses the LabVIEW{trademark} programming language allowing it to be easily ported between different computer operating systems. In the present configuration, digital signal processors are directly interfaced to a SCSI CAMAC controller. However, the modular software design permits the substitution of other hardware with LabVIEW-supported drivers. On-line displays of histogram and two-dimensional elemental map images provide a user-friendly data acquisition interface. Subregions of the two-dimensional maps may be selected interactively for detailed analysis or for subsequent scanning. Off-line data processing of archived data currently yields elemental maps, analyzed spectra and reconstructions of tomographic data.

  19. Scanning Electron Microscope Mapping System Developed for Detecting Surface Defects in Fatigue Specimens

    NASA Technical Reports Server (NTRS)

    Bonacuse, Peter J.; Kantzos, Peter T.

    2002-01-01

    An automated two-degree-of-freedom specimen positioning stage has been developed at the NASA Glenn Research Center to map and monitor defects in fatigue specimens. This system expedites the examination of the entire gauge section of fatigue specimens so that defects can be found using scanning electron microscopy (SEM). Translation and rotation stages are driven by microprocessor-based controllers that are, in turn, interfaced to a computer running custom-designed software. This system is currently being used to find and record the location of ceramic inclusions in powder metallurgy materials. The mapped inclusions are periodically examined during interrupted fatigue experiments. The number of cycles to initiate cracks from these inclusions and the rate of growth of initiated cracks can then be quantified. This information is necessary to quantify the effect of this type of defect on the durability of powder metallurgy materials. This system was developed with support of the Ultra Safe program.

  20. Nanoscale Electromechanics of Ferroelectric and Biological Systems: A New Dimension in Scanning Probe Microscopy

    SciTech Connect

    Kalinin, Sergei V; Rodriguez, Brian J; Jesse, Stephen; Karapetian, Edgar; Mirman, B; Eliseev, E. A.; Morozovska, A. N.

    2007-01-01

    Functionality of biological and inorganic systems ranging from nonvolatile computer memories and microelectromechanical systems to electromotor proteins and cellular membranes is ultimately based on the intricate coupling between electrical and mechanical phenomena. In the past decade, piezoresponse force microscopy (PFM) has been established as a powerful tool for nanoscale imaging, spectroscopy, and manipulation of ferroelectric and piezoelectric materials. Here, we give an overview of the fundamental image formation mechanism in PFM and summarize recent theoretical and technological advances. In particular, we show that the signal formation in PFM is complementary to that in the scanning tunneling microscopy (STM) and atomic force microscopy (AFM) techniques, and we discuss the implications. We also consider the prospect of extending PFM beyond ferroelectric characterization for quantitative probing of electromechanical behavior in molecular and biological systems and high-resolution probing of static and dynamic polarization switching processes in low-dimensional ferroelectric materials and heterostructures.

  1. A hand-held 3D laser scanning with global positioning system of subvoxel precision

    NASA Astrophysics Data System (ADS)

    Arias, Néstor; Meneses, Néstor; Meneses, Jaime; Gharbi, Tijani

    2011-01-01

    In this paper we propose a hand-held 3D laser scanner composed of an optical head device to extract 3D local surface information and a stereo vision system with subvoxel precision to measure the position and orientation of the 3D optical head. The optical head is manually scanned over the surface object by the operator. The orientation and position of the 3D optical head is determined by a phase-sensitive method using a 2D regular intensity pattern. This phase reference pattern is rigidly fixed to the optical head and allows their 3D location with subvoxel precision in the observation field of the stereo vision system. The 3D resolution achieved by the stereo vision system is about 33 microns at 1.8 m with an observation field of 60cm x 60cm.

  2. Multi-band automatic sun and sky scanning radiometer system for measurement of aerosols

    NASA Technical Reports Server (NTRS)

    Holben, B. N.; Eck, T. F.; Slutsker, I.; Tanre, D.; Buis, J. P.; Setzer, A.; Vermote, E.; Reagan, J. A.; Kaufman, Y. A.

    1994-01-01

    A weather resistant automatic scanning Sun photometer system is assessed and demonstrated as practical for measurements of aerosol concentrations and properties at remote sites. Interfaced with a transmitter using the Geostationary Data Collection System (GDCS), the data are processed in near real time. The processing allows a time dependence of the aerosols and water vapor and an ongoing assessment of the health and calibration of the instruments. The system's automatic data acquisition, transmission, and processing offer immediate application to atmospheric monitoring and modeling on a regional to global scale and validation of satellite retrievals. It is estimated that under normal circumstances the retrieved aerosol optical thickness has a network wide accuracy of +/- 0.02 from 340 nm to 1020 nm, water vapor +/- 0.2 cm and size distribution from 0.1 to 3 micrometers.

  3. Analysis of adaptive laser scanning optical system with focus-tunable components

    NASA Astrophysics Data System (ADS)

    Pokorný, P.; Mikš, A.; Novák, J.; Novák, P.

    2015-05-01

    This work presents a primary analysis of an adaptive laser scanner based on two-mirror beam-steering device and focustunable components (lenses with tunable focal length). It is proposed an optical scheme of an adaptive laser scanner, which can focus the laser beam in a continuous way to a required spatial position using the lens with tunable focal length. This work focuses on a detailed analysis of the active optical or opto-mechanical components (e.g. focus-tunable lenses) mounted in the optical systems of laser scanners. The algebraic formulas are derived for ray tracing through different configurations of the scanning optical system and one can calculate angles of scanner mirrors and required focal length of the tunable-focus component provided that the position of the focused beam in 3D space is given with a required tolerance. Computer simulations of the proposed system are performed using MATLAB.

  4. A high-resolution scanning pencil-beam scatterometer: system design challenges

    NASA Astrophysics Data System (ADS)

    Chakraborty, Prantik; Gupta, Priyanka; Misra, Tapan

    2016-05-01

    The scanning pencil-beam Scatterometer configuration is pretty effective in covering a large ground-swath by rotating a moderately sized paraboloid dish at a moderate speed. For example, Oscat (Oceansat-II Scatterometer) did cover a ground-swath of 1550km using a 1m diameter reflector that was rotated at 20.5 rpm. The decade-long service (1999-2009) provided by the Seawinds instrument onboard the Quikscat mission followed by an almost half-a-decade (2009-2014) service of Oscat has made this configuration tremendously popular with the global user community. A major drawback of conventional pencil-beam systems like Seawinds and Oscat is the relatively poor spatial resolution. The ground-resolution is beamwidth-limited azimuthally while, in elevation, the resolution is improved by engaging pulse-compression and range-binning. Oscat's Instantaneous Field of View (IFOV) was 25km wide in azimuth (az) and 50km in elevation (el) at 49° incidence angle. The range-compressed resolution bins had dimensions of 6km (el) x 25km (az). Therefore, qualified wind products could be generated upon square grids no finer than 25km x 25km resolution. According to recommendations of International Ocean Vector Wind Science Team (IOVWST) and Oscat user community, high-resolution scatterometry is the requirement of the day with wind-vector cell-size dimension of 5km or better. One way to improve the resolution is to adopt the SAR principle of Range-Doppler discrimination in the scanning pencil-beam configuration. The footprint can be resolved simultaneously in range as well as in azimuth, thus significantly improving the size of the combined Range-Doppler resolution bin ( 1km). However, the addition of Doppler filtering to conically scanning radar brings with it its own disadvantages e.g. the limitations of dwell time and the constant change in orientation of isodop lines. This paper presents the constraints in system design of high-resolution scanning systems, the design trade-offs, the

  5. The current state of electronic consultation and electronic referral systems in Canada: an environmental scan.

    PubMed

    Liddy, Clare; Hogel, Matthew; Blazkho, Valerie; Keely, Erin

    2015-01-01

    Access to specialist care is a point of concern for patients, primary care providers, and specialists in Canada. Innovative e-health platforms such as electronic consultation (eConsultation) and referral (eReferral) can improve access to specialist care. These systems allow physicians to communicate asynchronously and could reduce the number of unnecessary referrals that clog wait lists, provide a record of the patient's journey through the referral system, and lead to more efficient visits. Little is known about the current state of eConsultation and eReferral in Canada. The purpose of this work was to identify current systems and gain insight into the design and implementation process of existing systems. An environmental scan approach was used, consisting of a systematic and grey literature review, and targeted semi-structured key informant interviews. Only three eConsultation/eReferral systems are currently in operation in Canada. Four themes emerged from the interviews: eReferral is an end goal for those provinces without an active eReferral system, re-organization of the referral process is a necessity prior to automation, engaging the end-user is essential, and technological incompatibilities are major impediments to progress. Despite the acknowledged need to improve the referral system and increase government spending on health information technology, eConsultation and eReferral systems remain scarce as Canada lags behind the rest of the developed world.

  6. Accuracy improvement in laser stripe extraction for large-scale triangulation scanning measurement system

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Liu, Wei; Li, Xiaodong; Yang, Fan; Gao, Peng; Jia, Zhenyuan

    2015-10-01

    Large-scale triangulation scanning measurement systems are widely used to measure the three-dimensional profile of large-scale components and parts. The accuracy and speed of the laser stripe center extraction are essential for guaranteeing the accuracy and efficiency of the measuring system. However, in the process of large-scale measurement, multiple factors can cause deviation of the laser stripe center, including the spatial light intensity distribution, material reflectivity characteristics, and spatial transmission characteristics. A center extraction method is proposed for improving the accuracy of the laser stripe center extraction based on image evaluation of Gaussian fitting structural similarity and analysis of the multiple source factors. First, according to the features of the gray distribution of the laser stripe, evaluation of the Gaussian fitting structural similarity is estimated to provide a threshold value for center compensation. Then using the relationships between the gray distribution of the laser stripe and the multiple source factors, a compensation method of center extraction is presented. Finally, measurement experiments for a large-scale aviation composite component are carried out. The experimental results for this specific implementation verify the feasibility of the proposed center extraction method and the improved accuracy for large-scale triangulation scanning measurements.

  7. Evaluation of three different rotary systems during endodontic retreatment - Analysis by scanning electron microscopy

    PubMed Central

    Vidal, Flávia-Teixeira; Nunes, Eduardo; Horta, Martinho-Campolina-Rebello; Freitas, Maria-Rita-Lopes-da Silva

    2016-01-01

    Background Endodontic therapy is considered a series of important and interdependent steps, and failure of any of these steps may compromise the treatment outcome. This study aimed to evaluate the effectiveness of three different rotary systems in removing obturation materials during endodontic retreatment using scanning electron microscopy (SEM) analysis. Material and Methods Thirty-six endodontically treated teeth were selected and divided into 3 groups of 10 and 1 control group with 6 dental elements. The groups were divided according to the rotary system used for removing gutta-percha, as follows: G1: ProTaper system; G2: K3 system; G3: Mtwo system; and G4: Control group. Thereafter, the roots were split and the sections were observed under SEM, for analysis and counting of clear dentinal tubules, creating the variable “degree of dentinal tubule patency” (0: intensely clear; 1: moderately clear; 2: slightly clear; 3: completely blocked). The data were subjected to the Friedman and Kruskal-Wallis statistical tests. Results No differences were observed in the “degree of dentinal tubule patency” neither between the root thirds (to each evaluated group) nor between the groups (to each evaluated third). Nevertheless, when the three root thirds were grouped (providing evaluation of all root extension), the “degree of dentinal tubule patency” was lower in G1 than in G3 (p<0.05), but showed no differences neither between G1 and G2 nor G2 and G3. Conclusions No technique was able to completely remove the canal obturation material, despite G1 having shown better results, although without significant difference to G2 Key words:Scanning electron microscopy, NiTi, retreatment. PMID:27034750

  8. Scanning infrared remote sensing system for identification, visualization, and quantification of airborne pollutants

    NASA Astrophysics Data System (ADS)

    Harig, Roland; Matz, Gerhard; Rusch, Peter

    2002-02-01

    Remote sensing by Fourier-transform infrared (FTIR) spectrometry allows detection, identification, and quantification of airborne pollutants. In the case of leaks in pipelines or leaks in chemical plants, chemical accidents, terrorism, or war, hazardous compounds are often released into the atmosphere. Various Fourier-transform infrared spectrometers have been developed for the remote detection and identification of hazardous clouds. However, for the localization of a leak and a complete assessment of the situation in the case of the release of a hazardous cloud, information about the position and the size of a cloud is essential. Therefore, an imaging passive remote sensing system comprised of an interferometer (Bruker OPAG 22), a data acquisition, processing, and control system with a digital signal processor (FTIR DSP), an azimuth-elevation-scanning mirror, a video system with a DSP, and a personal computer has been developed. The FTIR DSP system controls the scanning mirror, collects the interferograms, and performs the Fourier transformation. The spectra are transferred to a personal computer and analyzed by a real-time identification algorithm that does not require background spectra for the analysis. The results are visualized by a video image, overlaid by false color images. For each target compound of a spectral library, images of the coefficient of correlation, the signal to noise ratio, the brightness temperature of the background, the difference between the temperature of the ambient air and the brightness temperature of the background, and the noise equivalent column density are produced. The column densities of all directions in which a target compound has been identified may be retrieved by a nonlinear least squares fitting algorithm and an additional false color image is displayed. The system has a high selectivity, low noise equivalent spectral radiance, and it allows identification, visualization, and quantification of pollutant clouds.

  9. Design and construction of a cost-efficient Arduino-based mirror galvanometer system for scanning optical microscopy

    NASA Astrophysics Data System (ADS)

    Hsu, Jen-Feng; Dhingra, Shonali; D'Urso, Brian

    2017-01-01

    Mirror galvanometer systems (galvos) are commonly employed in research and commercial applications in areas involving laser imaging, laser machining, laser-light shows, and others. Here, we present a robust, moderate-speed, and cost-efficient home-built galvo system. The mechanical part of this design consists of one mirror, which is tilted around two axes with multiple surface transducers. We demonstrate the ability of this galvo by scanning the mirror using a computer, via a custom driver circuit. The performance of the galvo, including scan range, noise, linearity, and scan speed, is characterized. As an application, we show that this galvo system can be used in a confocal scanning microscopy system.

  10. INNOVATIVE TECHNOLOGY VERIFICATION REPORT "FIELD MEASUREMENT TECHNOLOGIES FOR TOTAL PETROLEUM HYDROCARBONS IN SOIL" ENVIRONMENTAL SYSTEMS CORPORATION SYNCHRONOUS SCANNING LUMINOSCOPE

    EPA Science Inventory


    The Synchronous Scanning Luminoscope (Luminoscope) developed by the Oak Ridge National Laboratory in collaboration with Environmental Systems Corporation (ESC) was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program i...

  11. An efficient solid modeling system based on a hand-held 3D laser scan device

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2014-12-01

    The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

  12. Ultra-high vacuum compatible optical chopper system for synchrotron x-ray scanning tunneling microscopy

    SciTech Connect

    Chang, Hao; Cummings, Marvin; Shirato, Nozomi; Stripe, Benjamin; Preissner, Curt; Freeland, John W.; Rosenmann, Daniel; Kersell, Heath; Hla, Saw-Wai; Rose, Volker

    2016-01-28

    High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM.

  13. Non-contact in vivo diffuse optical imaging using a time-gated scanning system

    PubMed Central

    Mazurenka, M.; Di Sieno, L.; Boso, G.; Contini, D.; Pifferi, A.; Mora, A. Dalla; Tosi, A.; Wabnitz, H.; Macdonald, R.

    2013-01-01

    We report on the design and first in vivo tests of a novel non-contact scanning imaging system for time-domain near-infrared spectroscopy. Our system is based on a null source-detector separation approach and utilizes polarization-selective detection and a fast-gated single-photon avalanche diode to record late photons only. The in-vivo tests included the recording of hemodynamics during arm occlusion and two brain activation tasks. Localized and non-localized changes in oxy- and deoxyhemoglobin concentration were detected for motor and cognitive tasks, respectively. The tests demonstrate the feasibility of non-contact imaging of absorption changes in deeper tissues. PMID:24156081

  14. An Automated and Intelligent Medical Decision Support System for Brain MRI Scans Classification.

    PubMed

    Siddiqui, Muhammad Faisal; Reza, Ahmed Wasif; Kanesan, Jeevan

    2015-01-01

    A wide interest has been observed in the medical health care applications that interpret neuroimaging scans by machine learning systems. This research proposes an intelligent, automatic, accurate, and robust classification technique to classify the human brain magnetic resonance image (MRI) as normal or abnormal, to cater down the human error during identifying the diseases in brain MRIs. In this study, fast discrete wavelet transform (DWT), principal component analysis (PCA), and least squares support vector machine (LS-SVM) are used as basic components. Firstly, fast DWT is employed to extract the salient features of brain MRI, followed by PCA, which reduces the dimensions of the features. These reduced feature vectors also shrink the memory storage consumption by 99.5%. At last, an advanced classification technique based on LS-SVM is applied to brain MR image classification using reduced features. For improving the efficiency, LS-SVM is used with non-linear radial basis function (RBF) kernel. The proposed algorithm intelligently determines the optimized values of the hyper-parameters of the RBF kernel and also applied k-fold stratified cross validation to enhance the generalization of the system. The method was tested by 340 patients' benchmark datasets of T1-weighted and T2-weighted scans. From the analysis of experimental results and performance comparisons, it is observed that the proposed medical decision support system outperformed all other modern classifiers and achieves 100% accuracy rate (specificity/sensitivity 100%/100%). Furthermore, in terms of computation time, the proposed technique is significantly faster than the recent well-known methods, and it improves the efficiency by 71%, 3%, and 4% on feature extraction stage, feature reduction stage, and classification stage, respectively. These results indicate that the proposed well-trained machine learning system has the potential to make accurate predictions about brain abnormalities from the

  15. Development of a prototype pipework scanning system based upon energy dispersive X-ray diffraction (EDXRD)

    NASA Astrophysics Data System (ADS)

    Garrity, D. J.; De Rosa, A. J.; Bradley, D. A.; Jarman, S. E.; Jenneson, P. M.; Vincent, S. M.

    2010-07-01

    A prototype pipework scanning system based upon energy dispersive X-ray diffraction (EDXRD) has been produced, for which system development and preliminary results are presented here. This apparatus has been developed from experience with 2D and 3D bench-top EDXRD systems and comprises a conventional industrial X-ray tube coupled to a bespoke design of tungsten collimators and compact CdTe detector. It is designed as a robust system, rather than delicate lab-based system, to investigate sections of stainless steel pipework for structural changes induced through quenching the steel in liquid nitrogen, and damaging effects such as chloride-induced stress corrosion cracking (SCC). Given the properties of tungsten, namely its brittle nature, a complex programme of electro-discharge machining (EDM) has been devised to precisely manufacture the collimators from a series of sintered tungsten blocks. Preliminary measurements have focused on calibrating the system using the extreme ferrite and austenite phases, meeting a pre-requisite benchmark for attempting more challenging measurements such as the austenite to martensite transformation and investigations of SCC in these sections of pipework.

  16. Development of teaching modules for geology and engineering coursework using terrestrial LiDAR scanning systems

    NASA Astrophysics Data System (ADS)

    Yarbrough, L. D.; Katzenstein, K.

    2012-12-01

    Exposing students to active and local examples of physical geologic processes is beneficial to the learning process. Students typically respond with interest to examples that use state-of-the-art technologies to investigate local or regional phenomena. For lower cognitive level of learning (e.g. knowledge, comprehension, and application), the use of "close-to-home" examples ensures that students better understand concepts. By providing these examples, the students may already have a familiarity or can easily visit the location. Furthermore, these local and regional examples help students to offer quickly other examples of similar phenomena. Investigation of these examples using normal photographic techniques, as well as a more sophisticated 3-D Light Detection And Ranging (LiDAR) (AKA Terrestrial Laser Scanning or TLS) system, allows students to gain a better understanding of the scale and the mechanics of the geologic processes and hazards. The systems are used for research, teaching and outreach efforts and depending on departmental policies can be accessible to students are various learning levels. TLS systems can yield scans at sub-centimeter resolution and contain surface reflectance of targets. These systems can serve a number of learning goals that are essential for training geoscientists and engineers. While querying the data to answer geotechnical or geomorphologic related questions, students will develop skills using large, spatial databases. The upper cognitive level of learning (e.g. analysis, synthesis, and evaluation) is also promoted by using a subset of the data and correlating the physical geologic process of stream bank erosion and rock slope failures with mathematical and computer models using the scanned data. Students use the examples and laboratory exercises to help build their engineering judgment skills with Earth materials. The students learn not only applications of math and engineering science but also the economic and social implication

  17. Permanent 3D laser scanning system for an active landslide in Gresten (Austria)

    NASA Astrophysics Data System (ADS)

    Canli, Ekrem; Höfle, Bernhard; Hämmerle, Martin; Benni, Thiebes; Glade, Thomas

    2015-04-01

    Terrestrial laser scanners (TLS) have widely been used for high spatial resolution data acquisition of topographic features and geomorphic analyses. Existing applications encompass different landslides including rockfall, translational or rotational landslides, debris flow, but also coastal cliff erosion, braided river evolution or river bank erosion. The main advantages of TLS are (a) the high spatial sampling density of XYZ-measurements (e.g. 1 point every 2-3 mm at 10 m distance), particularly in comparison with the low data density monitoring techniques such as GNSS or total stations, (b) the millimeter accuracy and precision of the range measurement to centimeter accuracy of the final DEM, and (c) the highly dense area-wide scanning that enables to look through vegetation and to measure bare ground. One of its main constraints is the temporal resolution of acquired data due to labor costs and time requirements for field campaigns. Thus, repetition measurements are generally performed only episodically. However, for an increased scientific understanding of the processes as well as for early warning purposes, we present a novel permanent 3D monitoring setup to increase the temporal resolution of TLS measurements. This accounts for different potential monitoring deliverables such as volumetric calculations, spatio-temporal movement patterns, predictions and even alerting. This system was installed at the active Salcher landslide in Gresten (Austria) that is situated in the transition zone of the Gresten Klippenbelt (Helvetic) and the Flyschzone (Penninic). The characteristic lithofacies are the Gresten Beds of Early Jurassic age that are covered by a sequence of marly and silty beds with intercalated sandy limestones. Permanent data acquisition can be implemented into our workflow with any long-range TLS system offering fully automated capturing. We utilize an Optech ILRIS-3D scanner. The time interval between two scans is currently set to 24 hours, but can be

  18. Scanning electron microscope evidence for bacterial colonization of a drinking-water distribution system.

    PubMed Central

    Ridgway, H F; Olson, B H

    1981-01-01

    The surfaces of water distribution mains and suspended particulate matter from drinking water were examined by using scanning electron microscopy to investigate the nature and extent of association of microorganisms with these surfaces. In addition, X-ray energy-dispersive microanalysis was used to determine the elemental constitution of the pipe surface. Though distributed sparsely and randomly along the pipe surface, a variety of morphologically distinguishable bacteria-like structures and microcolonies were observed. The morphologies of the individual cells varied form chain-forming cocci to filamentous and prosthecate cell types. The iron-oxidizing bacterium Gallionella, recognized by its characteristic helical stalks, was observed both in water samples and attached to pipe surfaces. Attachment of some microbes to the pipe surface was apparently mediated by extracellular fibrillar appendages. Large numbers of rod-shaped bacteria were also evident adhering to the surfaces of suspended detritus or silt particles recovered from water samples by filtration. X-ray energy scans of the pipe surface revealed the presence of five major elemental constituents including silicon, phosphorous, sulfur, calcium, and iron. Smaller quantities of the elements zinc, magnesium, aluminum, potassium, and manganese were also detected. The public health significance of sessile microbial communities in drinking-water distribution systems is discussed. Images PMID:7013697

  19. Calibration improvements to electronically scanned pressure systems and preliminary statistical assessment

    NASA Technical Reports Server (NTRS)

    Everhart, Joel L.

    1996-01-01

    Orifice-to-orifice inconsistencies in data acquired with an electronically-scanned pressure system at the beginning of a wind tunnel experiment forced modifications to the standard, instrument calibration procedures. These modifications included a large increase in the number of calibration points which would allow a critical examination of the calibration curve-fit process, and a subsequent post-test reduction of the pressure data. Evaluation of these data has resulted in an improved functional representation of the pressure-voltage signature for electronically-scanned pressures sensors, which can reduce the errors due to calibration curve fit to under 0.10 percent of reading compared to the manufacturer specified 0.10 percent of full scale. Application of the improved calibration function allows a more rational selection of the calibration set-point pressures. These pressures should be adjusted to achieve a voltage output which matches the physical shape of the pressure-voltage signature of the sensor. This process is conducted in lieu of the more traditional approach where a calibration pressure is specified and the resulting sensor voltage is recorded. The fifteen calibrations acquired over the two-week duration of the wind tunnel test were further used to perform a preliminary, statistical assessment of the variation in the calibration process. The results allowed the estimation of the bias uncertainty for a single instrument calibration; and, they form the precursor for more extensive and more controlled studies in the laboratory.

  20. Microwave bone imaging: a preliminary scanning system for proof-of-concept

    PubMed Central

    Cuccaro, Antonio; Solimene, Raffaele; Brancaccio, Adriana; Basile, Bruno; Ammann, Max J.

    2016-01-01

    This Letter introduces a feasibility study of a scanning system for applications in biomedical bone imaging operating in the microwave range 0.5–4 GHz. Mechanical uncertainties and data acquisition time are minimised by using a fully automated scanner that controls two antipodal Vivaldi antennas. Accurate antenna positioning and synchronisation with data acquisition enables a rigorous proof-of-concept for the microwave imaging procedure of a multi-layer phantom including skin, fat, muscle and bone tissues. The presence of a suitable coupling medium enables antenna miniaturisation and mitigates the impedance mismatch between antennas and phantom. The three-dimensional image of tibia and fibula is successfully reconstructed by scanning the multi-layer phantom due to the distinctive dielectric contrast between target and surrounding tissues. These results show the viability of a microwave bone imaging technology which is low cost, portable, non-ionising, and does not require specially trained personnel. In fact, as no a-priori characterisation of the antenna is required, the image formation procedure is very conveniently simplified. PMID:27733930

  1. A high-voltage scanning electron microscopy system for in situ electromigration testing

    NASA Astrophysics Data System (ADS)

    Doan, J. C.; Lee, S.; Lee, S.-H.; Meier, N. E.; Bravman, J. C.; Flinn, P. A.; Marieb, T. N.; Madden, M. C.

    2000-07-01

    An apparatus has been constructed to conduct electromigration tests on realistic specimens while simultaneously observing them at relatively high magnification. A scanning transmission electron microscope has been converted into a high-voltage scanning electron microscope (HVSEM) with a large specimen chamber. By imaging with high-energy electrons (120 keV) and detecting backscattered electrons, voids in metal lines can be viewed through passivation layers. The HVSEM has a resolution of 50 nm through 1 μm of passivation. We have constructed instrumentation to heat and pass current through interconnect structures, while they are inside the electron microscope. Presently, the specimen temperature can be as high as 350 °C and is maintained constant to within 0.1 °C. The resistances of interconnects are measured with a precision of 0.05% during an experiment. Testing the lines at moderately accelerated conditions requires great stability of the microscope and instrumentation as well as full automation of the data collection. These requirements have been met, and metallization lines can be tested for several weeks with minimal operator intervention. Digital images of an entire 300-μm-long test structure as well as electrical data are stored automatically every few minutes during a test. The hundreds to thousands of pictures are analyzed using digital image processing techniques to extract void positions and sizes as a function of time. We use this system to characterize electromigration failure in advanced interconnect structures and to test existing theories on electromigration phenomenon.

  2. Secretory glands and microvascular systems imaged in aqueous solution by atmospheric scanning electron microscopy (ASEM).

    PubMed

    Yamazawa, Toshiko; Nakamura, Naotoshi; Sato, Mari; Sato, Chikara

    2016-12-01

    Exocrine glands, e.g., salivary and pancreatic glands, play an important role in digestive enzyme secretion, while endocrine glands, e.g., pancreatic islets, secrete hormones that regulate blood glucose levels. The dysfunction of these secretory organs immediately leads to various diseases, such as diabetes or Sjögren's syndrome, by poorly understood mechanisms. Gland-related diseases have been studied by optical microscopy (OM), and at higher resolution by transmission electron microscopy (TEM) of Epon embedded samples, which necessitates hydrophobic sample pretreatment. Here, we report the direct observation of tissue in aqueous solution by atmospheric scanning electron microscopy (ASEM). Salivary glands, lacrimal glands, and pancreas were fixed, sectioned into slabs, stained with phosphotungstic acid (PTA), and inspected in radical scavenger d-glucose solution from below by an inverted scanning electron microscopy (SEM), guided by optical microscopy from above to target the tissue substructures. A 2- to 3-µm specimen thickness was visualized by the SEM. In secretory cells, cytoplasmic vesicles and other organelles were clearly imaged at high resolution, and the former could be classified according to the degree of PTA staining. In islets of Langerhans, the microvascular system used as an outlet by the secretory cells was also clearly observed. Microvascular system is also critically involved in the onset of diabetic complications and was clearly visible in subcutaneous tissue imaged by ASEM. The results suggest the use of in-solution ASEM for histology and to study vesicle secretion systems. Further, the high-throughput of ASEM makes it a potential tool for the diagnosis of exocrine and endocrine-related diseases.

  3. Possibilities of a Personal Laser Scanning System for Forest Mapping and Ecosystem Services

    PubMed Central

    Liang, Xinlian; Kukko, Antero; Kaartinen, Harri; Hyyppä, Juha; Yu, Xiaowei; Jaakkola, Anttoni; Wang, Yunsheng

    2014-01-01

    A professional-quality, personal laser scanning (PLS) system for collecting tree attributes was demonstrated in this paper. The applied system, which is wearable by human operators, consists of a multi-constellation navigation system and an ultra-high-speed phase-shift laser scanner mounted on a rigid baseplate and consisting of a single sensor block. A multipass-corridor-mapping method was developed to process PLS data and a 2,000 m2 forest plot was utilized in the test. The tree stem detection accuracy was 82.6%; the root mean square error (RMSE) of the estimates of tree diameter at breast height (DBH) was 5.06 cm; the RMSE of the estimates of tree location was 0.38 m. The relative RMSE of the DBH estimates was 14.63%. The results showed, for the first time, the potential of the PLS system in mapping large forest plots. Further research on mapping accuracy in various forest conditions, data correction methods and multi-sensoral positioning techniques is needed. The utilization of this system in different applications, such as harvester operations, should also be explored. In addition to collecting tree-level and plot-level data for forest inventory, other possible applications of PLS for forest ecosystem services include mapping of canopy gaps, measuring leaf area index of large areas, documenting and visualizing forest routes feasible for recreation, hiking and berry and mushroom picking. PMID:24434879

  4. Three-dimensional microscope vision system based on micro laser line scanning and adaptive genetic algorithms

    NASA Astrophysics Data System (ADS)

    Apolinar, J.; Rodríguez, Muñoz

    2017-02-01

    A microscope vision system to retrieve small metallic surface via micro laser line scanning and genetic algorithms is presented. In this technique, a 36 μm laser line is projected on the metallic surface through a laser diode head, which is placed to a small distance away from the target. The micro laser line is captured by a CCD camera, which is attached to the microscope. The surface topography is computed by triangulation by means of the line position and microscope vision parameters. The calibration of the microscope vision system is carried out by an adaptive genetic algorithm based on the line position. In this algorithm, an objective function is constructed from the microscope geometry to determine the microscope vision parameters. Also, the genetic algorithm provides the search space to calculate the microscope vision parameters with high accuracy in fast form. This procedure avoids errors produced by the missing of references and physical measurements, which are employed by the traditional microscope vision systems. The contribution of the proposed system is corroborated by an evaluation via accuracy and speed of the traditional microscope vision systems, which retrieve micro-scale surface topography.

  5. Design and Implementation of a Mechanical Control System for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Bowden, William

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) will use technological improvements in low noise mixers to provide precise data on the Earth's atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a real time control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with a FPGA-based setup, we chose to use a low cost processor development kit manufactured by XMOS. The XMOS architecture allows parallel execution of multiple tasks on separate threads-making it ideal for this application and is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. For these reasons, the XMOS technology is an attractive, cost effective, alternative to FPGA-based technologies for this design and similar rapid prototyping projects.

  6. Science Data Processing for the Advanced Microwave Scanning Radiometer: Earth Observing System

    NASA Technical Reports Server (NTRS)

    Goodman, H. Michael; Regner, Kathryn; Conover, Helen; Ashcroft, Peter; Wentz, Frank; Conway, Dawn; Lobl, Elena; Beaumont, Bruce; Hawkins, Lamar; Jones, Steve

    2004-01-01

    The National Aeronautics and Space Administration established the framework for the Science Investigator-led Processing Systems (SIPS) to enable the Earth science data products to be produced by personnel directly associated with the instrument science team and knowledgeable of the science algorithms. One of the first instantiations implemented for NASA was the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) SIPS. The AMSR-E SIPS is a decentralized, geographically distributed ground data processing system composed of two primary components located in California and Alabama. Initial science data processing is conducted at Remote Sensing Systems (RSS) in Santa Rosa, California. RSS ingests antenna temperature orbit data sets from JAXA and converts them to calibrated, resampled, geolocated brightness temperatures. The brightness temperatures are sent to the Global Hydrology and Climate Center in Huntsville, Alabama, which generates the geophysical science data products (e.g., water vapor, sea surface temperature, sea ice extent, etc.) suitable for climate research and applications usage. These science products are subsequently sent to the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado for archival and dissemination to the at-large science community. This paper describes the organization, coordination, and production techniques employed by the AMSR-E SIPS in implementing, automating and operating the distributed data processing system.

  7. Research on high precision equal-angle scanning method in rotary kiln temperature measurement system

    NASA Astrophysics Data System (ADS)

    Dai, Shaosheng; Guo, Zhongyuan; You, Changhui; Liu, Jinsong; Cheng, Yang; Tang, Huaming

    2016-05-01

    Aiming at traditional horizontal equal-angle scanning method's disadvantage of measurement error, a high precision equal-angle scanning method is proposed, the proposed method establishes a tilt scanning model by the following steps: introducing height variable, precisely calculating the viewing angle, building scanning model. The model is used to calculate scanning position on rotary kiln's surface, which helps to locate and track temperature variation. The experiment shows that the proposed method can effectively improve the precision of temperature spots' location on the rotary kiln surface.

  8. Development of a Mechanical Scanning-type Intravascular Ultrasound System Using a Miniature Ultrasound Motor

    NASA Astrophysics Data System (ADS)

    Tanabe, Masayuki; Xie, Shangping; Tagawa, Norio; Moriya, Tadashi; Furukawa, Yuji

    2007-07-01

    Intravascular ultrasound (IVUS) plays an important role for the detection of arteriosclerosis, which causes the ischemic heart disease. In mechanical scanning-type IVUS, it is necessary to rotate a transducer or a reflecting mirror. A method that involves rotating the transducer using a torque wire causes image distortion (NURD: non uniform rotation distortion). For a method that involves placing an electromagnetic motor on the tip of an IVUS probe is difficult to miniaturize the probe. Our objectives are to miniaturize the probe (1 mm in diameter, 5 mm in length) and to remove NURD. Therefore, we conducted a study to assess the feasibility of attaining these objectives by constructing a prototype IVUS system, in which an ultrasound motor using a stator in the form of a helical coil (abbreviated as CS-USM: coiled stator-ultrasonic motor) is incorporated, and to clarify problems that need to be solved in constructing the probe.

  9. Geometric validation of a mobile laser scanning system for urban applications

    NASA Astrophysics Data System (ADS)

    Guan, Haiyan; Li, Jonathan; Yu, Yongtao; Liu, Yan

    2016-03-01

    Mobile laser scanning (MLS) technologies have been actively studied and implemented over the past decade, as their application fields are rapidly expanding and extending beyond conventional topographic mapping. Trimble's MX-8, as one of the MLS systems in the current market, generates rich survey-grade laser and image data for urban surveying. The objective of this study is to evaluate whether Trimble MX-8 MLS data satisfies the accuracy requirements of urban surveying. According to the formula of geo-referencing, accuracies of navigation solution and laser scanner determines the accuracy of the collected LiDAR point clouds. Two test sites were selected to test the performance of Trimble MX-8. Those extensive tests confirm that Trimble MX-8 offers a very promising tool to survey complex urban areas.

  10. Ultrasonic Guided-Wave Scan System Used to Characterize Microstructure and Defects in Ceramic Composites

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Cosgriff, Laura M.; Martin, Richard E.; Verrilli, Michael J.; Bhatt, Ramakrishna T.

    2004-01-01

    Ceramic matrix composites (CMCs) are being developed for advanced aerospace propulsion applications to save weight, improve reuse capability, and increase performance. However, mechanical and environmental loads applied to CMCs can cause discrete flaws and distributed microdamage, significantly reducing desirable physical properties. Such microdamage includes fiber/matrix debonding (interface failure), matrix microcracking, fiber fracture and buckling, oxidation, and second phase formation. A recent study (ref. 1) of the durability of a C/SiC CMC discussed the requirement for improved nondestructive evaluation (NDE) methods for monitoring degradation in these materials. Distributed microdamage in CMCs has proven difficult to characterize nondestructively because of the complex microstructure and macrostructure of these materials. This year, an ultrasonic guided-wave scan system developed at the NASA Glenn Research Center was used to characterize various microstructural and flaw conditions in SiC/SiC (silicon carbide fiber in silicon carbide matrix) and C/SiC (carbon fiber in silicon carbide matrix) CMC samples.

  11. Friedel oscillations in graphene-based systems probed by Scanning Tunneling Microscopy

    NASA Astrophysics Data System (ADS)

    Mallet, Pierre; Brihuega, Iván; Cherkez, Vladimir; Gómez-Rodríguez, Jose Marìa; Veuillen, Jean-Yves

    2016-03-01

    For the last 25 years, scientists have demonstrated the capabilities of Scanning Tunneling Microscopy (STM) to visualize in real space the response of a two-dimensional electron gas to atomic-scale impurities. The analysis of the Friedel oscillations surrounding the impurities yields valuable information regarding the elastic scattering properties, the band structure, the doping level and the symmetry of the electronic states in the two-dimensional host system. We will address in this article the use of this technique for probing the electronic properties of graphene, the star two-dimensional compound of the last decade. In particular, we will emphasize how this technique can be pushed up to unravel the electronic pseudospin, a distinctive degree of freedom of graphene's Dirac fermions.

  12. SAPling: a Scan-Add-Print barcoding database system to label and track asexual organisms

    PubMed Central

    Thomas, Michael A.; Schötz, Eva-Maria

    2011-01-01

    SUMMARY We have developed a ‘Scan-Add-Print’ database system, SAPling, to track and monitor asexually reproducing organisms. Using barcodes to uniquely identify each animal, we can record information on the life of the individual in a computerized database containing its entire family tree. SAPling has enabled us to carry out large-scale population dynamics experiments with thousands of planarians and keep track of each individual. The database stores information such as family connections, birth date, division date and generation. We show that SAPling can be easily adapted to other asexually reproducing organisms and has a strong potential for use in large-scale and/or long-term population and senescence studies as well as studies of clonal diversity. The software is platform-independent, designed for reliability and ease of use, and provided open source from our webpage to allow project-specific customization. PMID:21993779

  13. Comparative assessment of 3D surface scanning systems in breast plastic and reconstructive surgery.

    PubMed

    Patete, Paolo; Eder, Maximilian; Raith, Stefan; Volf, Alexander; Kovacs, Laszlo; Baroni, Guido

    2013-10-01

    In this work, we compared accuracy, repeatability, and usability in breast surface imaging of 2 commercial surface scanning systems and a hand-held laser surface scanner prototype coupled with a patient's motion acquisition and compensation methodology. The accuracy of the scanners was assessed on an anthropomorphic phantom, and to evaluate the usability of the scanners on humans, thorax surface images of 3 volunteers were acquired. Both the intrascanner repeatability and the interscanner comparative accuracy were assessed. The results showed surface-to-surface distance errors inferior to 1 mm and to 2 mm, respectively, for the 2 commercial scanners and for the prototypical one. Moreover, comparable performances of the 3 scanners were found when used for acquiring the breast surface. On the whole, this study demonstrated that handheld laser surface scanners coupled with subject motion compensation methods lend themselves as competitive technologies for human body surface modeling.

  14. LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments.

    PubMed

    Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha

    2015-07-10

    A new scan that matches an aided Inertial Navigation System (INS) with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies-INS and LiDAR SLAM-into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform-NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment.

  15. CHARACTERISING THE EOS SLOT-SCANNING SYSTEM WITH THE EFFECTIVE DETECTIVE QUANTUM EFFICIENCY.

    PubMed

    Clavel, A H; Monnin, P; Létang, J M; Verdun, F R; Darbon, A

    2016-06-01

    As opposed to the standard detective quantum efficiency (DQE), effective DQE (eDQE) is a figure of merit that allows comparing the performances of imaging systems in the presence of scatter rejection devices. The geometry of the EOS™ slot-scanning system is such that the detector is self-collimated and rejects scattered radiation. In this study, the EOS system was characterised using the eDQE in imaging conditions similar to those used in clinical practice: with phantoms of different widths placed in the X-ray beam, for various incident air kerma and tube voltages corresponding to the phantom thickness. Scatter fractions in EOS images were extremely low, around 2 % for all configurations. Maximum eDQE values spanned 9-14.8 % for a large range of air kerma at the detector plane from 0.01 to 1.34 µGy. These figures were obtained with non-optimised EOS setting but still over-performed most of the maximum eDQEs recently assessed for various computed radiology and digital radiology systems with antiscatter grids.

  16. LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments

    PubMed Central

    Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha

    2015-01-01

    A new scan that matches an aided Inertial Navigation System (INS) with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies—INS and LiDAR SLAM—into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform—NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment. PMID:26184206

  17. An Airborne Scanning LiDAR System for Ocean and Coastal Applications

    NASA Astrophysics Data System (ADS)

    Reineman, B. D.; Lenain, L.; Castel, D.; Melville, W. K.

    2008-12-01

    We have developed an airborne scanning LiDAR (Light Detection And Ranging) system and demonstrated its functionality for terrestrial and oceanographic measurements. Differential GPS (DGPS) and an Inertial Navigation System (INS) are synchronized with the LiDAR, providing end result vertical rms errors of approximately 6~cm. Flying 170~m above the surface, we achieve a point density of ~ 0.7 m-2 and a swath width of 90 to 120~m over ocean and 200~m over land. Georeferencing algorithms were developed in-house and earth-referenced data are available several hours after acquisition. Surveys from the system are compared with ground DGPS surveys and existing airborne surveys of fixed targets. Twelve research flights in a Piper Twin Comanche from August 2007 to July 2008 have provided topography of the Southern California coastline and sea surface wave fields in the nearshore ocean environment. Two of the flights also documented the results of the October 2007 landslide on Mt.~Soledad in La Jolla, California. Eight research flights aboard a Cessna Caravan surveyed the topography, lagoon, reef, and surrounding seas of Lady Elliot Island (LEI) in Australia's Great Barrier Reef in April 2008. We describe applications for the system, including coastal topographic surveys, wave measurements, reef research, and ship wake studies.

  18. Atmospheric scanning electron microscope system with an open sample chamber: configuration and applications.

    PubMed

    Nishiyama, Hidetoshi; Koizumi, Mitsuru; Ogawa, Koji; Kitamura, Shinich; Konyuba, Yuji; Watanabe, Yoshiyuki; Ohbayashi, Norihiko; Fukuda, Mitsunori; Suga, Mitsuo; Sato, Chikara

    2014-12-01

    An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240°C and sintered.

  19. 3-D ultrasonic strain imaging based on a linear scanning system.

    PubMed

    Huang, Qinghua; Xie, Bo; Ye, Pengfei; Chen, Zhaohong

    2015-02-01

    This paper introduces a 3-D strain imaging method based on a freehand linear scanning mode. We designed a linear sliding track with a position sensor and a height-adjustable holder to constrain the movement of an ultrasound probe in a freehand manner. When moving the probe along the sliding track, the corresponding positional measures for the probe are transmitted via a wireless communication module based on Bluetooth in real time. In a single examination, the probe is scanned in two sweeps in which the height of the probe is adjusted by the holder to collect the pre- and postcompression radio-frequency echoes, respectively. To generate a 3-D strain image, a volume cubic in which the voxels denote relative strains for tissues is defined according to the range of the two sweeps. With respect to the post-compression frames, several slices in the volume are determined and the pre-compression frames are re-sampled to precisely correspond to the post-compression frames. Thereby, a strain estimation method based on minimizing a cost function using dynamic programming is used to obtain the 2-D strain image for each pair of frames from the re-sampled pre-compression sweep and the post-compression sweep, respectively. A software system is developed for volume reconstruction, visualization, and measurement of the 3-D strain images. The experimental results show that high-quality 3-D strain images of phantom and human tissues can be generated by the proposed method, indicating that the proposed system can be applied for real clinical applications (e.g., musculoskeletal assessments).

  20. Image-guided intervention in the human bile duct using scanning fiber endoscope system

    NASA Astrophysics Data System (ADS)

    Seibel, Eric J.; Jo, Javier A.; Melville, C. David; Johnston, Richard S.; Naumann, Christopher R.; Saunders, Michael D.

    2012-01-01

    Bile duct cancers are increasing in frequency while being difficult to diagnose. Currently available endoscopic imaging devices used in the biliary tree are low resolution with poor image quality, leading to inadequate evaluation of indeterminate biliary strictures. However, a new ultrathin and flexible cholangioscope system has been successfully demonstrated in a human subject. This mini-cholangioscope system uses a scanning fiber endoscope (SFE) as a forward-imaging guidewire, dimensions of 1.2-mm diameter and 3-m length. Full color video (500-line resolution at 30Hz) is the standard SFE imaging mode using spiral scanning of red, green, and blue laser light at low power. Image-guided operation of the biopsy forceps was demonstrated in healthy human bile ducts with and without saline flushing. The laser-based video imaging can be switched to various modes to enhance tissue markers of disease, such as widefield fluorescence and enhanced spectral imaging. In parallel work, biochemical discrimination of tissue health in pig bile duct has been accomplished using fiberoptic delivery of pulsed UV illumination and time-resolved autofluorescence spectroscopic measurements. Implementation of time-resolved fluorescence spectroscopy for biochemical assessment of the bile duct wall is being done through a secondary endoscopic channel. Preliminary results indicate that adequate SNR levels (> 30 dB) can be achieved through a 50 micron fiber, which could serve as an optical biopsy probe. The SFE is an ideal mini-cholangioscope for integration of both tissue and molecular specific image contrast in the future. This will provide the physician with unprecedented abilities to target biopsy locations and perform endoscopically-guided therapies.

  1. Measuring contact area, force, and pressure for bioengineering applications: using Fuji Film and TekScan systems.

    PubMed

    Bachus, Kent N; DeMarco, Alyssa L; Judd, Kyle T; Horwitz, Daniel S; Brodke, Darrel S

    2006-06-01

    The goal of this study was to compare the TekScan I-Scan Pressure Measurement System with two methods of analysis involving the Fuji Film Prescale Pressure Measuring System in estimating area, force and pressure. Fuji Film and TekScan sensors were alternately placed between a cylindrical peg and a finely ground steel base plate, and compressed with known forces. All Fuji stains were digitally scanned and analyzed. The Erase method of Fuji Film analysis consisted of manually removing portions of the image judged by the user to be outside the perimeter of the stain. The second method of Fuji Film analysis, termed the Threshold method, used the threshold tool to analyze only those pixels that were stained from loading. The TekScan system utilized special matrix-based sensors interfaced with a Windows compatible desktop computer that was equipped with specialized data acquisition hardware and analysis software. The data from this study did not support the hypothesis that all three methods would have accuracies within +/-5% of a known value, when estimating area, force and pressure. Specifically, the TekScan system was found to be more accurate than either of the Fuji Film methods when estimating area and pressure.

  2. Development of the compact proton beam therapy system dedicated to spot scanning with real-time tumor-tracking technology

    NASA Astrophysics Data System (ADS)

    Umezawa, Masumi; Fujimoto, Rintaro; Umekawa, Tooru; Fujii, Yuusuke; Takayanagi, Taisuke; Ebina, Futaro; Aoki, Takamichi; Nagamine, Yoshihiko; Matsuda, Koji; Hiramoto, Kazuo; Matsuura, Taeko; Miyamoto, Naoki; Nihongi, Hideaki; Umegaki, Kikuo; Shirato, Hiroki

    2013-04-01

    Hokkaido University and Hitachi Ltd. have started joint development of the Gated Spot Scanning Proton Therapy with Real-Time Tumor-Tracking System by integrating real-time tumor tracking technology (RTRT) and the proton therapy system dedicated to discrete spot scanning techniques under the "Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program)". In this development, we have designed the synchrotron-based accelerator system by using the advantages of the spot scanning technique in order to realize a more compact and lower cost proton therapy system than the conventional system. In the gated irradiation, we have focused on the issues to maximize irradiation efficiency and minimize the dose errors caused by organ motion. In order to understand the interplay effect between scanning beam delivery and target motion, we conducted a simulation study. The newly designed system consists of the synchrotron, beam transport system, one compact rotating gantry treatment room with robotic couch, and one experimental room for future research. To improve the irradiation efficiency, the new control function which enables multiple gated irradiations per synchrotron cycle has been applied and its efficacy was confirmed by the irradiation time estimation. As for the interplay effect, we confirmed that the selection of a strict gating width and scan direction enables formation of the uniform dose distribution.

  3. Global Quick Scan of the Vulnerability of Groundwater systems to Tsunamis

    NASA Astrophysics Data System (ADS)

    Oude Essink, Gualbert; Faneca Sànchez, Marta; Zamrsky, Daniel

    2014-05-01

    Fresh groundwater resources in deltaic areas are used for domestic, agricultural and industrial purposes. These resources in the coastal zone are threatened by salinization of the aquifers due to global change (increase of groundwater extraction due to population growth), climate change (including sea level rise), as well as natural disasters such as floods and tsunamis. Studies of how the coastal fresh groundwater resources are affected by the latter phenomena are often done a posteriori, especially the studies related to tsunami effects (e.g. the 2003 Sumatra Tsunami). Then it is often too late to take appropriated measures to counteract the negative effects (e.g. on drinking water supply). These complex studies are time consuming, and need data which might not be available at the time of the disaster when a fast reaction of the water authorities is needed, e.g. to facilitate a quick and easy to access fresh water supply system. In our study we present a Global Quick Scan of the vulnerability of the deltaic fresh groundwater resources to tsunamis. We created a global database including the data needed to generate fast and simple models on the salinization of groundwater systems in the coastal zone. These quantifications give water manager a first approximation of the effects that a tsunami would have on the salinization of the fresh groundwater. The data collected in this database has been used to generate a map showing the areas with coastal groundwater systems vulnerable to tsunami effects, as well as a dataset of 500 2D models representing the physical characteristics of the most frequent coastal groundwater systems in tsunami vulnerable areas. These 2D models simulate the loss in fresh groundwater volume of the system and the characteristic time of a system before it recovers 90% of the fresh groundwater that was available previous to the tsunami event. A similar approach could be adopted for assessing the effect of sea level rise and future increased

  4. A System Architecture for Sharing De-Identified, Research-Ready Brain Scans and Health Information Across Clinical Imaging Centers

    PubMed Central

    Chervenak, Ann L.; van Erp, Theo G.M.; Kesselman, Carl; D’Arcy, Mike; Sobell, Janet; Keator, David; Dahm, Lisa; Murry, Jim; Law, Meng; Hasso, Anton; Ames, Joseph; Macciardi, Fabio; Potkin, Steven G.

    2015-01-01

    Progress in our understanding of brain disorders increasingly relies on the costly collection of large standardized brain magnetic resonance imaging (MRI) data sets. Moreover, the clinical interpretation of brain scans benefits from compare and contrast analyses of scans from patients with similar, and sometimes rare, demographic, diagnostic, and treatment status. A solution to both needs is to acquire standardized, research-ready clinical brain scans and to build the information technology infrastructure to share such scans, along with other pertinent information, across hospitals. This paper describes the design, deployment, and operation of a federated imaging system that captures and shares standardized, de-identified clinical brain images in a federation across multiple institutions. In addition to describing innovative aspects of the system architecture and our initial testing of the deployed infrastructure, we also describe the Standardized Imaging Protocol (SIP) developed for the project and our interactions with the Institutional Review Board (IRB) regarding handling patient data in the federated environment. PMID:22941984

  5. Evaluation of the propulsion control system of a planetary rover and design of a mast for an elevation scanning laser/multi-detector system

    NASA Technical Reports Server (NTRS)

    Knaub, D.; Yerazunis, S. W.

    1978-01-01

    Vertical wheel loads, wheel speeds, and torque relationships are considered in the design of a propulsion system capable of responding to steering, slope climbing, and irregular local terrains. The system developed is applied to the RPI Mars roving vehicle. The mechanical system required to implement the elevation laser scanning/multidetector principle was the design and construction of a mechanical system for implementing the elevation scanning/multidetector principle is also discussed.

  6. Vibration Pattern Imager (VPI): A control and data acquisition system for scanning laser vibrometers

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.; Brown, Donald E.; Shaffer, Thomas A.

    1993-01-01

    The Vibration Pattern Imager (VPI) system was designed to control and acquire data from scanning laser vibrometer sensors. The PC computer based system uses a digital signal processing (DSP) board and an analog I/O board to control the sensor and to process the data. The VPI system was originally developed for use with the Ometron VPI Sensor, but can be readily adapted to any commercially available sensor which provides an analog output signal and requires analog inputs for control of mirror positioning. The sensor itself is not part of the VPI system. A graphical interface program, which runs on a PC under the MS-DOS operating system, functions in an interactive mode and communicates with the DSP and I/O boards in a user-friendly fashion through the aid of pop-up menus. Two types of data may be acquired with the VPI system: single point or 'full field.' In the single point mode, time series data is sampled by the A/D converter on the I/O board (at a user-defined sampling rate for a selectable number of samples) and is stored by the PC. The position of the measuring point (adjusted by mirrors in the sensor) is controlled via a mouse input. The mouse input is translated to output voltages by the D/A converter on the I/O board to control the mirror servos. In the 'full field' mode, the measurement point is moved over a user-selectable rectangular area. The time series data is sampled by the A/D converter on the I/O board (at a user-defined sampling rate for a selectable number of samples) and converted to a root-mean-square (rms) value by the DSP board. The rms 'full field' velocity distribution is then uploaded for display and storage on the PC.

  7. Imaging of aphakic intraocular lens with a slit-scanning tomography system

    NASA Astrophysics Data System (ADS)

    Oliveira, Cristina M.; Almeida, J. B.; Franco, S.

    2011-05-01

    Nowadays, cataract extraction with IOL implantation aims not only to restore the crystalline lens' transparency, but also to improve patients' retinal image quality. The refractive outcome and visual quality in pseudophakic eyes is mainly determined by the combination of corneal and internal optics resulting from the implanted IOLs. The optical function of the IOLs depends on its position in the eye. The IOL distance to the corneal apex determines the optical power needed for optical correction. In this paper it is described the usage of a slit-scanning imaging system to determine IOL positioning. Through the projection of the light from a slit onto the eye, this tomography system allows to acquire multiple sections of the anterior eye segment, at different meridians. The developed system's software corrects geometric and optical distortion of the images and provides 3-dimentional models of the eye's structures from the 2-dimensional sections. With this noninvasive technique, cross-sectional images of an eye with an aphakic IOL were obtained in order to reconstruct its 3- dimensional model of the lens and assess its position in the anterior segment camera.

  8. Optimization of an adaptive SPECT system with the scanning linear estimator

    NASA Astrophysics Data System (ADS)

    Ghanbari, Nasrin; Clarkson, Eric; Kupinski, Matthew A.; Li, Xin

    2015-08-01

    The adaptive single-photon emission computed tomography (SPECT) system studied here acquires an initial scout image to obtain preliminary information about the object. Then the configuration is adjusted by selecting the size of the pinhole and the magnification that optimize system performance on an ensemble of virtual objects generated to be consistent with the scout data. In this study the object is a lumpy background that contains a Gaussian signal with a variable width and amplitude. The virtual objects in the ensemble are imaged by all of the available configurations and the subsequent images are evaluated with the scanning linear estimator to obtain an estimate of the signal width and amplitude. The ensemble mean squared error (EMSE) on the virtual ensemble between the estimated and the true parameters serves as the performance figure of merit for selecting the optimum configuration. The results indicate that variability in the original object background, noise and signal parameters leads to a specific optimum configuration in each case. A statistical study carried out for a number of objects show that the adaptive system on average performs better than its nonadaptive counterpart.

  9. A New High Channel-Count, High Scan-Rate, Data Acquisition System for the NASA Langley Transonic Dynamics Tunnel

    NASA Technical Reports Server (NTRS)

    Ivanco, Thomas G.; Sekula, Martin K.; Piatak, David J.; Simmons, Scott A.; Babel, Walter C.; Collins, Jesse G.; Ramey, James M.; Heald, Dean M.

    2016-01-01

    A data acquisition system upgrade project, known as AB-DAS, is underway at the NASA Langley Transonic Dynamics Tunnel. AB-DAS will soon serve as the primary data system and will substantially increase the scan-rate capabilities and analog channel count while maintaining other unique aeroelastic and dynamic test capabilities required of the facility. AB-DAS is configurable, adaptable, and enables buffet and aeroacoustic tests by synchronously scanning all analog channels and recording the high scan-rate time history values for each data quantity. AB-DAS is currently available for use as a stand-alone data system with limited capabilities while development continues. This paper describes AB-DAS, the design methodology, and the current features and capabilities. It also outlines the future work and projected capabilities following completion of the data system upgrade project.

  10. A wire scanning based method for geometric calibration of high resolution CT system

    NASA Astrophysics Data System (ADS)

    Jiang, Ruijie; Li, Guang; Gu, Ning; Chen, Gong; Luo, Shouhua

    2015-03-01

    This paper is about geometric calibration of the high resolution CT (Computed Tomography) system. Geometric calibration refers to the estimation of a set of parameters that describe the geometry of the CT system. Such parameters are so important that a little error of them will degrade the reconstruction images seriously, so more accurate geometric parameters are needed in the higher-resolution CT systems. But conventional calibration methods are not accurate enough for the current high resolution CT system whose resolution can reach sub-micrometer or even tens of nanometers. In this paper, we propose a new calibration method which has higher accuracy and it is based on the optimization theory. The superiority of this method is that we build a new cost function which sets up a relationship between the geometrical parameters and the binary reconstruction image of a thin wire. When the geometrical parameters are accurate, the cost function reaches its maximum value. In the experiment, we scanned a thin wire as the calibration data and a thin bamboo stick as the validation data to verify the correctness of the proposed method. Comparing with the image reconstructed with the geometric parameters calculated by using the conventional calibration method, the image reconstructed with the parameters calculated by our method has less geometric artifacts, so it can verify that our method can get more accurate geometric calibration parameters. Although we calculated only one geometric parameter in this paper, the geometric artifacts are still eliminated significantly. And this method can be easily generalized to all the geometrical parameters calibration in fan-beam or cone-beam CT systems.

  11. PSIDD3: Post-Scan Ultrasonic Data Display System for the Windows-Based PC Including Fuzzy Logic Analysis

    NASA Technical Reports Server (NTRS)

    Lovelace, Jeffrey J.; Cios, Krzysztof J.; Roth, Don J.; Cao, Wei

    2000-01-01

    Post-Scan Interactive Data Display (PSIDD) III is a user-oriented Windows-based system that facilitates the display and comparison of ultrasonic contact data. The system is optimized to compare ultrasonic measurements made at different locations within a material or at different stages of material degradation. PSIDD III provides complete analysis of the primary wave forms in the time and frequency domains along with the calculation of several frequency dependent properties including Phase Velocity and Attenuation Coefficient and several frequency independent properties, like the Cross Correlation Velocity. The system allows image generation on all of the frequency dependent properties at any available frequency (limited by the bandwidth used in the scans) and on any of the frequency independent properties. From ultrasonic contact scans, areas of interest on an image can be studied with regard to underlying raw waveforms and derived ultrasonic properties by simply selecting the point on the image. The system offers various modes of in-depth comparison between scan points. Up to five scan points can be selected for comparative analysis at once. The system was developed with Borland Delphi software (Visual Pascal) and is based on a SQL database. It is ideal for classification of material properties, or location of microstructure variations in materials.

  12. Design and implementation of fiber-based multiphoton endoscopy with microelectromechanical systems scanning

    NASA Astrophysics Data System (ADS)

    Tang, Shuo; Jung, Woonggyu; McCormick, Daniel; Xie, Tuqiang; Su, Jiangping; Ahn, Yeh-Chan; Tromberg, Bruce J.; Chen, Zhongping

    2009-05-01

    A multiphoton endoscopy system has been developed using a two-axis microelectromechanical systems (MEMS) mirror and double-cladding photonic crystal fiber (DCPCF). The MEMS mirror has a 2-mm-diam, 20-deg optical scanning angle, and 1.26-kHz and 780-Hz resonance frequencies on the x and y axes. The maximum number of resolvable focal spots of the MEMS scanner is 720×720 on the x and y axes, which indicates that the MEMS scanner can potentially support high-resolution multiphoton imaging. The DCPCF is compared with standard single-mode fiber and hollow-core photonic bandgap fiber on the basis of dispersion, attenuation, and coupling efficiency properties. The DCPCF has high collection efficiency, and its dispersion can be compensated by grating pairs. Three configurations of probe design are investigated, and their imaging quality and field of view are compared. A two-lens configuration with a collimation and a focusing lens provides the optimum imaging performance and packaging flexibility. The endoscope is applied to image fluorescent microspheres and bovine knee joint cartilage.

  13. Scanning laser edema index: a reliable tool to correlate with diabetic retinopathy and systemic risk factors?

    PubMed

    Peyman, Mohammadreza; Tajunisah, Iqbal; Loo, Angela; Chuah, Khai Choon; Subrayan, Visvaraja

    2012-01-01

    To correlate Heidelberg Retina Tomograph (HRT) derived macular edema (DME) index with severity of diabetic retinopathy and systemic factors. A total of 300 diabetic patients were recruited for the study for each of them a value for the macular edema index was obtained using the HRT II. Patients' age, gender, duration and type of diabetes mellitus, latest HbA1c result and presence or absence of co-morbid factors (hypertension, ischemic heart disease, nephropathy) were recorded together with the stage of diabetic retinopathy. These were correlated with DME. Out of 300 patients, HRT defined macula edema was seen in 68 patients (22.6%). There is a wider and higher range (95% percentile) of macula edema index in the severe non proliferative diabetic retinopathy (NPDR) group. Independent samples t test showed significant difference between the severe NPDR group and no DR group (p<0.001), mild NPDR group (p<0.05) and moderate NPDR group (p<0.05). A higher macula edema index was also found to have a low degree of correlation with more advanced stages of retinopathy (r=0.310; p<0.001). Also nephropathy showed a strong and significant correlation with DME. Hypertension had moderately significant correlation with DME. This study found no correlation between ischemic heart disease and DME. HRT derived scanning laser edema index is a reliable objective tool to evaluate diabetic retinopathy and systemic risk factors.

  14. Design of high precision motor driving system for circular scanning ultrasonic endoscopic imaging equipment

    NASA Astrophysics Data System (ADS)

    Deng, Haoran; Bai, Baoping; Chen, Xiaodong; Zhao, Qiang; Li, Yanan; Wang, Yi; Yu, Daoyin

    2013-12-01

    This paper describes the development of a motor driving system for circular scanning ultrasonic endoscopic imaging equipment. It was designed to guarantee the motor rotating at a relatively constant speed in load fluctuation conditions, which result from the bending and twisting of the flexible shaft which connects the probe to the motor. A hardware feedback circuit based on Frequency-To-Voltage Converter LM331 and Step-Down Voltage Regulator LM2576-ADJ was designed to ensure steady rotation of motor in load fluctuation conditions, and a D/A module offered by MCU was used to regulate the real-time rotary speed. The feedback response cycle is about 20 μs according to theoretical analysis. Experimental results show that the maximum error is +/-1 r/min under the normal running environment (300 ~1500 r/min) and load fluctuation conditions, which means the average instability is reduced to 0.11% as compared with that of the motor drive simply based on MCU which is 0.94%. Both theoretical analysis and experimental results indicate that the motor driving system has high accuracy, fast response, excellent reliability and good versatility and portability, and can precisely guarantee the smooth movement of load-changing PMW (Pulse Width Modulation) motor, so as to ensure the imaging quality, and can effectively improve the efficiency and accuracy of the diagnosis.

  15. Scanning electron microscopy evaluation of the interface of three adhesive systems.

    PubMed

    Macari, Soraia; Gonçalves, Mariane; Nonaka, Tomio; Santos, Jaime Maia dos

    2002-01-01

    The objective of this research was to investigate the resin-dentin interface of three adhesive systems, Scotchbond Multi-Purpose, Optibond and Denthesive Bond II by scanning electron microscopy. The adhesives and their respective composite resins were applied inside the cervical root canal of human incisors and canines according to manufacturer recommendations. The teeth were embedded in acrylic resin and sliced transversally to the root canal and perpendicularly to the resin-dentin interface. The adhesive systems Scotchbond Multi-Purpose and Optibond had a homogenous hybrid layer and similar characteristics, involving resin penetration of peritubular and intertubular dentin matrix. Morphological differences of resin tags were seen; Scotchbond Multi-Purpose had more and longer tags than Optibond. Denthesive Bond II did not have the same consistency of bonding. Tubular orifices were not opened and the smear layer was not removed. This was due to the absence of previous acid conditioning of dentin that damages hybrid layer formation. Analysis of the hybrid layer revealed different patterns, suggesting that the attachment was influenced by many factors and a standardization of dentinal substrate was impossible.

  16. A new generation of detectors for scanning x-ray beam imaging systems

    NASA Astrophysics Data System (ADS)

    Rommel, J. Martin

    2016-01-01

    Scanning x-ray beam imaging systems were first developed by American Science and Engineering, Inc. (AS&E) in the early 1970s [1]. Since then, these systems have found a wide range of applications in security inspection and non-destructive testing. Large-area detectors are most frequently used to collect backscattered radiation but smaller transmission detectors are also employed for selected applications. Until recently, only two basic detector designs have been used: large scintillator blocks with attached photomultiplier tubes (PMTs) or large-volume light-sealed boxes, lined with scintillating screens and port windows for PMTs. In both cases, the detectors have required considerable depth to provide acceptable light collection efficiency. A new design recently developed by AS&E relies on wavelength shifting fibres (WSF) for light collection. For the first time, this approach enables the construction of thin large-area detectors. Stacking layers of WSF ribbons and scintillating screens in varying combinations enables optimization of the detection efficiency for different applications. Taking separate readings from different layers provides an energy-sensitive signal combination. Energy sensitivity can be improved further by adding filtration between the signal channels. Several prototype configurations have been built and characterized for both backscatter and transmission imaging. A WSF-based detector has been commercialized for a transmission x-ray imaging application.

  17. Intercalibration method for underwater three-dimensional mapping laser line scan systems.

    PubMed

    Moore, K D

    2001-11-20

    I present a method to calibrate absolutely a new family of underwater bathymetric laser scanner systems that use a single target range. Depth is calculated by triangulation among the source, the receiver, and the instantaneous position of a single spot produced by a highly collimated laser beam scanned across the target. For calibration, the refractive index of seawater is used to modulate the triangulation parameters rather than use of different target ranges to calibrate for extended range operation. Exploitation of a unique triangulation configuration allows the receiver characteristics to be ignored initially so that the scanner parameters can be determined. This allows the accurate positioning of the laser spot so that the receiver, in turn, can be calibrated. This intercalibration method provides high-resolution parameterization of the source-receiver characteristics and their geometric layout within the system so that an absolute bathymetric calibration can be realized in situ. In addition, a theoretical model derived to develop the methodology can be used to characterize and optimize future designs.

  18. Surface scanning inspection system particle detection dependence on aluminum film morphology

    NASA Astrophysics Data System (ADS)

    Prater, Walter; Tran, Natalie; McGarvey, Steve

    2012-03-01

    Physical vapor deposition (PVD) aluminum films present unique challenges when detecting particulate defects with a Surface Scanning Inspection System (SSIS). Aluminum (Al) films 4500Å thick were deposited on 300mm particle grade bare Si wafers at two temperatures using a Novellus Systems INOVA® NExT,.. Film surface roughness and morphology measurements were performed using a Veeco Vx310® atomic force microscope (AFM). AFM characterization found the high deposition temperature (TD) Al roughness (Root Mean Square 16.5 nm) to be five-times rougher than the low-TD Al roughness (rms 3.7 nm). High-TD Al had grooves at the grain boundaries that were measured to be 20 to 80 nm deep. Scanning electron microscopy (SEM) examination, with a Hitachi RS6000 defect review SEM, confirmed the presence of pronounced grain grooves. SEM images established that the low-TD filmed wafers have fine grains (0.1 to 0.3 um diameter) and the high-TD film wafers have fifty-times larger equiaxed plateletshape grains (5 to 15 um diameter). Calibrated Poly-Styrene Latex (PSL) spheres ranging in size from 90 nm to 1 μm were deposited in circular patterns on the wafers using an aerosol deposition chamber. PSL sphere depositions at each spot were controlled to yield 2000 to 5000 counts. A Hitachi LS9100® dark field full wafer SSIS was used to experimentally determine the relationship of the PSL sphere scattered light intensity with S-polarized light, a measure of scattering cross-section, with respect to the calibrated PSL sphere diameter. Comparison of the SSIS scattered light versus PSL spot size calibration curves shows two distinct differences. Scattering cross-section (intensity) of the PSL spheres increased on the low-TD Al film with smooth surface roughness and the low-TD Al film defect detection sensitivity was 126 nm compared to 200 nm for the rougher high- TD Al film. This can be explained by the higher signal to noise attributed to the smooth low-TD Al. Dark field defect detection on

  19. Nuclear Scans

    MedlinePlus

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  20. WBC scan

    MedlinePlus

    ... in the body. It is a type of nuclear scan . How the Test is Performed Blood will ... radiation. Due to the slight radiation exposure, most nuclear scans (including WBC scan) are not recommended for ...

  1. Liver scan

    MedlinePlus

    ... Nuclear scan - technetium; Nuclear scan - liver or spleen Images Liver scan References Lidofsky S. Jaundice. In: Feldman M, ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  2. PET scan

    MedlinePlus

    ... may have an allergic reaction to the tracer material. Some people have pain, redness, or swelling at ... with diabetes. Most PET scans are now performed along with a CT scan. This combination scan ...

  3. Development of a C-Scan phased array ultrasonic imaging system using a 64-element 35MHz transducer

    NASA Astrophysics Data System (ADS)

    Zheng, Fan; Hu, Changhong; Zhang, Lequan; Snook, Kevin; Liang, Yu; Hackenberger, Wesley S.; Liu, Ruibin; Geng, Xuecang; Jiang, Xiaoning; Shung, K. Kirk

    2011-04-01

    Phased array imaging systems provide the features of electronic beam steering and dynamic depth focusing that cannot be obtained with conventional linear array systems. This paper presents a system design of a digital ultrasonic imaging system, which is capable of handling a 64-element 35MHz center frequency phased array transducer. The system consists of 5 parts: an analog front-end, a data digitizer, a DSP based beamformer, a computer controlled motorized linear stage, and a computer for post image processing and visualization. Using a motorized linear stage, C-scan images, parallel to the surface of scanned objects may be generated. This digital ultrasonic imaging system in combination a 35 MHz phased array appears to be a promising tool for NDT applications with high spatial resolution. It may also serve as an excellent research platform for high frequency phased array design and testing as well as ultrasonic array signal algorithm developing using system's raw RF data acquisition function.

  4. SU-E-T-73: Commissioning of a Treatment Planning System for Proton Spot Scanning

    SciTech Connect

    Saini, J; Kang, Y; Schultz, L; Nicewonger, D; Herrera, M; Wong, T; Bowen, S; Bloch, C

    2014-06-01

    Purpose: A treatment planning system (TPS) was commissioned for clinical use with a fixed beam line proton delivery system. An outline of the data collection, modeling, and verification is provided. Methods: Beam data modeling for proton spot scanning in CMS Xio TPS requires the following measurements: (i) integral depth dose curves (IDDCs); (ii) absolute dose calibration; and (iii) beam spot characteristics. The IDDCs for 18 proton energies were measured using an integrating detector in a single spot field in a water phantom. Absolute scaling of the IDDCs were performed based on ion chamber measurements in mono-energetic 10×10 cm{sup 2} fields in water. Beam spot shapes were measured in air using a flat panel scintillator detector at multiple planes. For beam model verification, more than 45 uniform dose phantom and patient plans were generated. These plans were used to measure range, point dose, and longitudinal and lateral profiles. Tolerances employed for verification are: point dose and longitudinal profiles, ±2%; range, ±1 mm; FWHM for lateral profiles, ±2 mm; and patient plan dose distribution, gamma index of >90% at 3%/3 mm criteria. Results: More than 97% of the point dose measurements out of 115 were within +/-2% with maximum deviation of 3%. 98% of the ranges measured were within 1 mm with maximum deviation of 1.4mm. The normalized depth doses were within 2% at all depths. The maximum error in FWHM of lateral profiles was found to be less than 2mm. For 5 patient plans representing different anatomic sites, a total of 38 planes for 12 beams were analyzed for gamma index with average value of 99% and minimum of 94%. Conclusions: The planning system is successfully commissioned and can be safely deployed for clinical use. Measurements of IDDCs on user beam are highly recommended instead of using standard beam IDDCs.

  5. Application of a hybrid 3D-2D laser scanning system to the characterization of slate slabs.

    PubMed

    López, Marcos; Martínez, Javier; Matías, José María; Vilán, José Antonio; Taboada, Javier

    2010-01-01

    Dimensional control based on 3D laser scanning techniques is widely used in practice. We describe the application of a hybrid 3D-2D laser scanning system to the characterization of slate slabs with structural defects that are difficult for the human eye to characterize objectively. Our study is based on automating the process using a 3D laser scanner and a 2D camera. Our results demonstrate that the application of this hybrid system optimally characterizes slate slabs in terms of the defects described by the Spanish UNE-EN 12326-1 standard.

  6. INS/GPS/LiDAR Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm.

    PubMed

    Gao, Yanbin; Liu, Shifei; Atia, Mohamed M; Noureldin, Aboelmagd

    2015-09-15

    This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (LiDAR) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and LiDAR measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and LiDAR measurements are rich, LiDAR replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and LiDAR with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory.

  7. INS/GPS/LiDAR Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm

    PubMed Central

    Gao, Yanbin; Liu, Shifei; Atia, Mohamed M.; Noureldin, Aboelmagd

    2015-01-01

    This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (LiDAR) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and LiDAR measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and LiDAR measurements are rich, LiDAR replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and LiDAR with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory. PMID:26389906

  8. Robust Dead Reckoning System for Mobile Robots Based on Particle Filter and Raw Range Scan

    PubMed Central

    Duan, Zhuohua; Cai, Zixing; Min, Huaqing

    2014-01-01

    Robust dead reckoning is a complicated problem for wheeled mobile robots (WMRs), where the robots are faulty, such as the sticking of sensors or the slippage of wheels, for the discrete fault models and the continuous states have to be estimated simultaneously to reach a reliable fault diagnosis and accurate dead reckoning. Particle filters are one of the most promising approaches to handle hybrid system estimation problems, and they have also been widely used in many WMRs applications, such as pose tracking, SLAM, video tracking, fault identification, etc. In this paper, the readings of a laser range finder, which may be also interfered with by noises, are used to reach accurate dead reckoning. The main contribution is that a systematic method to implement fault diagnosis and dead reckoning in a particle filter framework concurrently is proposed. Firstly, the perception model of a laser range finder is given, where the raw scan may be faulty. Secondly, the kinematics of the normal model and different fault models for WMRs are given. Thirdly, the particle filter for fault diagnosis and dead reckoning is discussed. At last, experiments and analyses are reported to show the accuracy and efficiency of the presented method. PMID:25192318

  9. The ventricular system of the pigeon brain: a scanning electron microscope study.

    PubMed Central

    Mestres, P; Rascher, K

    1994-01-01

    The fine structural features and regional differences of the ependyma in adult pigeons have been investigated by scanning electron microscopy. Pigeons of either sex were fixed with buffered glutaraldehyde (3%) and formaldehyde (0.5%) by intravascular perfusion. The brain was dissected using section planes adequate to expose each part of the ventricular system. The specimens were then dehydrated, critical point dried and sputtered with gold. Depending upon the distribution of cilia, microvilli and single cilia, different areas were recognised in the 4 ventricles. The topographic locations of these areas were determined using the atlas of Karten & Hodos (1967). The medial surfaces of the 1st and 2nd lateral ventricles are more densely ciliated than the lateral surfaces. In the floor of the 4th ventricle the medial part is less ciliated than the lateral parts. The circumventricular organs (subseptal organ, organum vasculosum of the lamina terminalis, infundibulum, choroid plexus, subcommissural organ, area postrema) show very characteristic surfaces and are surrounded by a transitional zone with the nonspecialized ependyma. In contrast, in the paraventricular organ the transition to the nonspecialized ependyma is rather abrupt. The ependyma covering the trochlear nucleus appears densely ciliated, differing from that of the classic circumventricular organs. Finally, the existence of openings in the caudal medullary velum, which represent direct communications between the ventricles and the subarachnoid space, was demonstrated. Images Fig. 2 Fig. 3 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 PMID:8157492

  10. A servomechanism for a micro-electro-mechanical-system-based scanning-probe data storage device

    NASA Astrophysics Data System (ADS)

    Pantazi, A.; Lantz, M. A.; Cherubini, G.; Pozidis, H.; Eleftheriou, E.

    2004-10-01

    Micro-electro-mechanical-system (MEMS)-based scanning-probe data storage devices are emerging as potential ultra-high-density, low-access-time, and low-power alternatives to conventional data storage. One implementation of probe-based storage uses thermomechanical means to store and retrieve information in thin polymer films. One of the challenges in building such devices is the extreme accuracy and the short latency required in the navigation of the probes over the polymer medium. This paper focuses on the design and characterization of a servomechanism to achieve such accurate positioning in a probe-based storage prototype. In our device, the polymer medium is positioned on a MEMS scanner with x/y-motion capabilities of about 100 µm. The device also includes thermal position sensors that provide x/y-position information to the servo controller. Based on a discrete state-space model of the scanner dynamics, a controller is designed using the linear quadratic Gaussian approach with state estimation. The random seek performance of this approach is evaluated and compared with that of the conventional proportional, integrator, and derivative (PID) approach. The results demonstrate the superiority of the state-space approach, which achieves seek times of about 4 ms in a ± 50 µm range. Finally, the experimental results show that closed-loop track following using the thermal position-sensor signals is feasible and yields a position-error standard deviation of approximately 2 nm.

  11. Application of chemometric methods to differential scanning calorimeter (DSC) to estimate nimodipine polymorphs from cosolvent system.

    PubMed

    Siddiqui, Akhtar; Rahman, Ziyaur; Khan, Mansoor A

    2015-06-01

    The focus of this study was to evaluate the applicability of chemometrics to differential scanning calorimetry data (DSC) to evaluate nimodipine polymorphs. Multivariate calibration models were built using DSC data from known mixtures of the nimodipine modification. The linear baseline correction treatment of data was used to reduce dispersion in thermograms. Principal component analysis of the treated and untreated data explained 96% and 89% of the data variability, respectively. Score and loading plots correlated variability between samples with change in proportion of nimodipine modifications. The R(2) for principal component regression (PCR) and partial lease square regression (PLS) were found to be 0.91 and 0.92. The root mean square of standard error of the treated samples for calibration and validation in PCR and PLS was found to be lower than the untreated sample. These models were applied to samples recrystallized from a cosolvent system, which indicated different proportion of modifications in the mixtures than those obtained by placing samples under different storage conditions. The model was able to predict the nimodipine modifications with known margin of error. Therefore, these models can be used as a quality control tool to expediently determine the nimodipine modification in an unknown mixture.

  12. State of the art of 3D scanning systems and inspection of textile surfaces

    NASA Astrophysics Data System (ADS)

    Montilla, M.; Orjuela-Vargas, S. A.; Philips, W.

    2014-02-01

    The rapid development of hardware and software in the digital image processing field has boosted research in computer vision for applications in industry. The development of new electronic devices and the tendency to decrease their prices makes possible new developments that few decades ago were possible only in the imagination. This is the case of 3D imaging technology which permits to detect failures in industrial products by inspecting aspects on their 3D surface. In search of an optimal solution for scanning textiles we present in this paper a review of existing techniques for digitizing 3D surfaces. Topographic details of textiles can be obtained by digitizing surfaces using laser line triangulation, phase shifting optical triangulation, projected-light, stereo-vision systems and silhouette analysis. Although we are focused on methods that have been used in the textile industry, we also consider potential mechanisms used for other applications. We discuss the advantages and disadvantages of the evaluated methods and state a summary of potential implementations for the textile industry.

  13. A-scan ultrasound system for real-time puncture safety assessment during percutaneous nephrolithotomy

    NASA Astrophysics Data System (ADS)

    Rodrigues, Pedro L.; Rodrigues, Nuno F.; Fonseca, Jaime C.; von Krüger, M. A.; Pereira, W. C. A.; Vilaça, João. L.

    2015-03-01

    Background: Kidney stone is a major universal health problem, affecting 10% of the population worldwide. Percutaneous nephrolithotomy is a first-line and established procedure for disintegration and removal of renal stones. Its surgical success depends on the precise needle puncture of renal calyces, which remains the most challenging task for surgeons. This work describes and tests a new ultrasound based system to alert the surgeon when undesirable anatomical structures are in between the puncture path defined through a tracked needle. Methods: Two circular ultrasound transducers were built with a single 3.3-MHz piezoelectric ceramic PZT SN8, 25.4 mm of radius and resin-epoxy matching and backing layers. One matching layer was designed with a concave curvature to work as an acoustic lens with long focusing. The A-scan signals were filtered and processed to automatically detect reflected echoes. Results: The transducers were mapped in water tank and tested in a study involving 45 phantoms. Each phantom mimics different needle insertion trajectories with a percutaneous path length between 80 and 150 mm. Results showed that the beam cross-sectional area oscillates around the ceramics radius and it was possible to automatically detect echo signals in phantoms with length higher than 80 mm. Conclusions: This new solution may alert the surgeon about anatomical tissues changes during needle insertion, which may decrease the need of X-Ray radiation exposure and ultrasound image evaluation during percutaneous puncture.

  14. Differential scanning microcalorimetry indicates that human defensin, HNP-2, interacts specifically with biomembrane mimetic systems.

    PubMed

    Lohner, K; Latal, A; Lehrer, R I; Ganz, T

    1997-02-11

    alpha-Defensins are antimicrobial peptides with 29-35 amino acid residues and cysteine-stabilized amphiphilic, triple-stranded beta-sheet structures. We used high-precision differential scanning microcalorimetry to investigate the effects of a human neutrophil alpha-defensin, HNP-2, on the phase behavior of model membranes mimicking bacterial and erythrocyte cell membranes. In the presence of this positively charged peptide, the phase behavior of liposomes containing negatively charged phosphatidylglycerol was markedly altered even at a high lipid-to-peptide molar ratio of 500:1. Addition of HNP-2 to liposomes mimicking bacterial membranes (mixtures of dipalmitoylphosphatidylglycerol and -ethanolamine) resulted in phase separation owing to some domains being peptide-poor and others peptide-rich. The latter are characterized by an increase of the main transition temperature, most likely arising from electric shielding of the phospholipid headgroups by the peptide. On the other hand, HNP-2 did not affect the phase behavior of membranes mimicking erythrocyte membranes (equimolar mixtures of dipalmitoylphosphatidylcholine and sphingomyelin) as well as the pure single components. This is in contrast to melittin, which significantly affected the phase behavior of choline phospholipids in accordance with its unspecific lytic activity. These results support the hypothesis of preferential interaction of defensins with negatively charged membrane cell surfaces, a common feature of bacterial cell membranes, and demonstrate that HNP-2 discriminates between model membrane systems mimicking prokaryotic and eukaryotic cell membranes.

  15. a Feasibility Study on Use of Generic Mobile Laser Scanning System for Detecting Asphalt Pavement Cracks

    NASA Astrophysics Data System (ADS)

    Chen, Xinqu; Li, Jonathan

    2016-06-01

    This study aims to automatically detect pavement cracks on urban roads by employing the 3D point clouds acquired by a mobile laser scanning (MLS) system. Our method consists of four steps: ground point filtering, high-pass convolution, matched filtering, and noise removal. First, a voxel-based upward growing method is applied to construct Digital Terrain Model (DTM) of the road surface. Then, a high-pass filter convolutes the DTM to detect local elevation changes that may embed cracking information. Next, a two-step matched filter is applied to extract crack features. Lastly, a noise removal process is conducted to refine the results. Instead of using MLS intensity, this study takes advantages of the MLS elevation information to perform automated crack detection from large-volume, mixed-density, unstructured MLS point clouds. Four types of cracks including longitudinal, transvers, random, and alligator cracks are detected. Our results demonstrated that the proposed method works well with the RIEGL VMX-450 point clouds and can detect cracks in moderate-to-severe severity (13 - 25 mm) within a 200 m by 30 m urban road segment located in Kingston, Ontario, at one time. Due to the resolution capability, small cracks with slight severity remain unclear in the MLS point cloud.

  16. Optical detection of metastatic cancer cells using a scanned laser pico-projection system

    NASA Astrophysics Data System (ADS)

    Huang, Chih-Ling; Chiu, Wen-Tai; Lo, Yu-Lung; Chuang, Chin-Ho; Chen, Yu-Bin; Chang, Shu-Jing; Ke, Tung-Ting; Cheng, Hung-Chi; Wu, Hua-Lin

    2015-03-01

    Metastasis is responsible for 90% of all cancer-related deaths in humans. As a result, reliable techniques for detecting metastatic cells are urgently required. Although various techniques have been proposed for metastasis detection, they are generally capable of detecting metastatic cells only once migration has already occurred. Accordingly, the present study proposes an optical method for physical characterization of metastatic cancer cells using a scanned laser pico-projection system (SLPP). The validity of the proposed method is demonstrated using five pairs of cancer cell lines and two pairs of non-cancer cell lines treated by IPTG induction in order to mimic normal cells with an overexpression of oncogene. The results show that for all of the considered cell lines, the SLPP speckle contrast of the high-metastatic cells is significantly higher than that of the low-metastatic cells. As a result, the speckle contrast measurement provides a reliable means of distinguishing quantitatively between low- and high-metastatic cells of the same origin. Compared to existing metastasis detection methods, the proposed SLPP approach has many advantages, including a higher throughput, a lower cost, a larger sample size and a more reliable diagnostic performance. As a result, it provides a highly promising solution for physical characterization of metastatic cancer cells in vitro.

  17. Monte-Carlo simulation of a slot-scanning X-ray imaging system.

    PubMed

    Kulkarni, Mayuresh; Dendere, Ronald; Nicolls, Fred; Steiner, Stef; Douglas, Tania S

    2016-01-01

    We present a method for simulating slot-scanning X-ray imaging using the general-purpose Monte Carlo simulation package PENELOPE and penEasy Imaging. Different phantoms can be defined with the PENGEOM package, which defines bodies as combinations of volumes limited by quadric surfaces. The source-detector geometry, the position of the object, the collimator, the X-ray tube properties, the detector material and the pixel dimensions are defined. The output of the time-delay integration detector is simulated using sequential slot outputs derived from penEasy Imaging. The simulations are validated using tungsten and aluminium test objects, which are both simulated and imaged. The simulations are compared to the X-ray images using standard image quality metrics. The MTF, NPS and DQE curves show that the real and simulated X-ray images are comparable in terms of spatial resolution, noise and frequency information. The implementation can be modified to suit alterations in the system being simulated.

  18. Image-based autonomous micromanipulation system for arrangement of spheres in a scanning electron microscope

    NASA Astrophysics Data System (ADS)

    Kasaya, Takeshi; Miyazaki, Hideki T.; Saito, Shigeki; Koyano, Koichi; Yamaura, Tomio; Sato, Tomomasa

    2004-06-01

    The micromanipulation technique in a scanning electron microscope (SEM) has been attracting interest as a technique to produce microstructures such as three-dimensional photonic crystals or advanced high-density electronic circuits. However, it is difficult to fabricate a large-scale structure or to conduct a systematic experiment using numbers of structures, as long as we rely on manually operated micromanipulation. In this study, we constructed an automatic system which arranges 10-μm-sized microspheres into a given two-dimensional pattern in a SEM. The spheres are picked up by touching with the center of the planar tip of a probe (needle), and placed on the substrate by moving the contact point to the edge of the tip and inclining the probe. The positions of the probe and the spheres are visually recognized from the SEM image from above and the optical microscope image from the side. The generalized Hough transform, which can robustly detect arbitrary shape from the edge fragments, is employed for the image recognition. Contact force information obtained by a force sensor with a resolution of 14 μN is also utilized for the control. Completely automatic rearrangement of randomly sprinkled metal spheres with a diameter of 30 μm into arbitrary patterns was successfully demonstrated. Autonomous micromanipulation technique under the observation of a SEM would contribute not merely to laboratories but also to the opto-electronics industry.

  19. Integrated cantilever fabrication and system development for ultrasonic and acoustic scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Olson, Stephen; Sankaran, Balasubramanian; Altemus, Bruce; Xu, Bai; Geer, Robert

    2005-05-01

    Although the conventional optical lever technology typically used for scanning probe microscope applications has proven highly sensitive, accurate, and cost effective for most applications involving micromachined cantilever deflection measurements, frequency limitations and space needs limit its applicability to emerging ultrasonic-based SPM applications. Recently, the fabrication of cantilevers integrated with actuation and sensing components has opened avenues for feedback-based driving of micromachined cantilevers at higher-order resonance frequencies while sensing average deflection without the need for an optical deflection pathway for average deflection sensing. The work presented here will review recent efforts by our group in fabricating micromachined cantilevers with integrated piezoresistive deflection-sensing components combined with integrated ZnO actuation layers to induce cantilever deflection. These cantilevers are being fabricated for use in a heterodyne force microscopy system (HFM) to enable SPM imaging contrast based on viscoelastic response of a surface in contact with a micromachined tip wherein active-feedback technology is being applied to maintain ultrasonic tip excitation at higher order cantilever resonances. The first and second-pass fabrication results will be presented and reviewed regarding cantilever release and ZnO actuator (and electrode) fabrication. Dynamic response data from these structures, measured via laser Doppler vibrometery reveal the expected resonance structure for a cantilever of these dimensions.

  20. Feasibility of fiber optic displacement sensor scanning system for imaging of dental cavity

    NASA Astrophysics Data System (ADS)

    Rahman, Husna Abdul; Che Ani, Adi Izhar; Harun, Sulaiman Wadi; Yasin, Moh.; Apsari, Retna; Ahmad, Harith

    2012-07-01

    The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm 0.775 mV/mm and 0.4 mm 0.5109 mV/mm and 0.5 mm and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.

  1. Cosmetic and aesthetic skin photosurgery using a computer-assisted CO2 laser-scanning system

    NASA Astrophysics Data System (ADS)

    Dutu, Doru C. A.; Dumitras, Dan C.; Nedelcu, Ioan; Ghetie, Sergiu D.

    1997-12-01

    Since the first application of CO2 laser in skin photosurgery, various techniques such as laser pulsing, beam scanning and computer-assisted laser pulse generator have been introduced for the purpose of reducing tissue carbonization and thermal necrosis. Using a quite simple XY optical scanner equipped with two galvanometric driven mirrors and an appropriate software to process the scanning data and control the interaction time and energy density in the scanned area, we have obtained a device which can improve CO2 laser application in cosmetic and aesthetic surgery. The opto-mechanical CO2 laser scanner based on two total reflecting flat mirrors placed at 90 degree(s) in respect to the XY scanning directions and independently driven through a magnetic field provides a linear movement of the incident laser beam in the operating field. A DA converter supplied with scanning data by the software enables a scanning with linearity better than 1% for a maximum angular deviation of 20 degree(s). Because the scanning quality of the laser beam in the operating field is given not only by the displacement function of the two mirrors, but also by the beam characteristics in the focal plane and the cross distribution in the laser beam, the surgeon can control through software either the scanning field dimensions or the distance between two consecutive points of the vertically and/or horizontally sweep line. The development of computer-assisted surgical scanning techniques will help control the surgical laser, to create either a reproducible incision with a controlled depth or a controlled incision pattern with minimal incision width, a long desired facility for plastic surgery, neurosurgery, ENT and dentistry.

  2. An explanation for the extremely low, but variable, radiation dosages measured in a linear slit scanning radiography system

    NASA Astrophysics Data System (ADS)

    Potgieter, J. H.; de Villiers, Mattieu; Scheelke, Martin; de Jager, Gerhard

    2005-04-01

    Clinical trials performed for the FDA"s Section 510k compliance submission of the Statscan digital, full-body, linear slit scanning diagnostic radiography system revealed that comparable diagnostic results with a commercial full-field screen film device were obtained with the Statscan using much lower radiation doses. For certain imaging procedures the doses for Statscan were as much as twenty to thirty times lower. However the results varied by a large amount and in particular the results for chest radiographs were anomalous in that the Statscan dose was less reduced. Whilst it is well known that slit scanning radiography has considerably lower radiation exposure than full-field devices due to its much lower scatter to primary ratio and also that digital radiography has the potential for lower radiation dosages, it was thought that that this alone did not fully account for the dose differences. This paper suggests that these dose differences, including the anomaly mentioned above, can be explained by considering the unique way that slit scanning is undertaken by Statscan i.e. by scanning the tube, detector, slit and collimators together along a linear path. The effect on measured skin entrance doses is explained and the dosage differences as affected by digital technology, higher DQE, slit scanning (low scatter to primary ratio) and linear slit scanning methods are quantified. Furthermore it is explained how the Statscan geometry leads an improved "skin sparing" effect.

  3. Nanostructure characterization by a combined x-ray absorption/scanning force microscopy system.

    PubMed

    Pilet, Nicolas; Raabe, Joerg; Stevenson, Stephanie E; Romer, Sara; Bernard, Laetitia; McNeill, Christopher R; Fink, Rainer H; Hug, Hans J; Quitmann, Christoph

    2012-11-30

    A combined x-ray transmission and scanning force microscope setup (NanoXAS) recently installed at a dedicated beamline of the Swiss Light Source combines complementary experimental techniques to access chemical and physical sample properties with nanometer scale resolution. While scanning force microscopy probes physical properties such as sample topography, local mechanical properties, adhesion, electric and magnetic properties on lateral scales even down to atomic resolution, scanning transmission x-ray microscopy offers direct access to the local chemical composition, electronic structure and magnetization. Here we present three studies which underline the advantages of complementary access to nanoscale properties in prototype thin film samples.

  4. A dynamic collimation system for penumbra reduction in spot-scanning proton therapy: Proof of concept

    SciTech Connect

    Hyer, Daniel E. Hill, Patrick M.; Wang, Dongxu; Smith, Blake R.; Flynn, Ryan T.

    2014-09-15

    Purpose: In the absence of a collimation system the lateral penumbra of spot scanning (SS) dose distributions delivered by low energy proton beams is highly dependent on the spot size. For current commercial equipment, spot size increases with decreasing proton energy thereby reducing the benefit of the SS technique. This paper presents a dynamic collimation system (DCS) for sharpening the lateral penumbra of proton therapy dose distributions delivered by SS. Methods: The collimation system presented here exploits the property that a proton pencil beam used for SS requires collimation only when it is near the target edge, enabling the use of trimmers that are in motion at times when the pencil beam is away from the target edge. The device consists of two pairs of parallel nickel trimmer blades of 2 cm thickness and dimensions of 2 cm × 18 cm in the beam's eye view. The two pairs of trimmer blades are rotated 90° relative to each other to form a rectangular shape. Each trimmer blade is capable of rapid motion in the direction perpendicular to the central beam axis by means of a linear motor, with maximum velocity and acceleration of 2.5 m/s and 19.6 m/s{sup 2}, respectively. The blades travel on curved tracks to match the divergence of the proton source. An algorithm for selecting blade positions is developed to minimize the dose delivered outside of the target, and treatment plans are created both with and without the DCS. Results: The snout of the DCS has outer dimensions of 22.6 × 22.6 cm{sup 2} and is capable of delivering a minimum treatment field size of 15 × 15 cm{sup 2}. Using currently available components, the constructed system would weigh less than 20 kg. For irregularly shaped fields, the use of the DCS reduces the mean dose outside of a 2D target of 46.6 cm{sup 2} by approximately 40% as compared to an identical plan without collimation. The use of the DCS increased treatment time by 1–3 s per energy layer. Conclusions: The spread of the

  5. Design and operation of gamma scan and fission gas sampling systems for characterization of irradiated commercial nuclear fuel

    SciTech Connect

    Knox, C.A.; Thornhill, R.E.; Mellinger, G.B.

    1989-09-01

    One of the primary objectives of the Materials Characterization Center (MCC) is to acquire and characterize spent fuels used in waste form testing related to nuclear waste disposal. The initial steps in the characterization of a fuel rod consist of gamma scanning the rod and sampling the gas contained in the fuel rod (referred to as fission gas sampling). The gamma scan and fission gas sampling systems used by the MCC are adaptable to a wide range of fuel types and have been successfully used to characterize both boiling water reactor (BWR) and pressurized water reactor (PWR) fuel rods. This report describes the design and operation of systems used to gamma scan and fission gas sample full-length PWR and BWR fuel rods. 1 ref., 10 figs., 1 tab.

  6. Characterizing a Proton Beam Scanning System for Monte Carlo Dose Calculation in Patients

    PubMed Central

    Grassberger, C; Lomax, Tony; Paganetti, H

    2015-01-01

    The presented work has two goals. First, to demonstrate the feasibility of accurately characterizing a proton radiation field at treatment head exit for Monte Carlo dose calculation of active scanning patient treatments. Second, to show that this characterization can be done based on measured depth dose curves and spot size alone, without consideration of the exact treatment head delivery system. This is demonstrated through calibration of a Monte Carlo code to the specific beam lines of two institutions, Massachusetts General Hospital (MGH) and Paul Scherrer Institute (PSI). Comparison of simulations modeling the full treatment head at MGH to ones employing a parameterized phase space of protons at treatment head exit reveals the adequacy of the method for patient simulations. The secondary particle production in the treatment head is typically below 0.2% of primary fluence, except for low–energy electrons (<0.6MeV for 230MeV protons), whose contribution to skin dose is negligible. However, there is significant difference between the two methods in the low-dose penumbra, making full treatment head simulations necessary to study out-of field effects such as secondary cancer induction. To calibrate the Monte Carlo code to measurements in a water phantom, we use an analytical Bragg peak model to extract the range-dependent energy spread at the two institutions, as this quantity is usually not available through measurements. Comparison of the measured with the simulated depth dose curves demonstrates agreement within 0.5mm over the entire energy range. Subsequently, we simulate three patient treatments with varying anatomical complexity (liver, head and neck and lung) to give an example how this approach can be employed to investigate site-specific discrepancies between treatment planning system and Monte Carlo simulations. PMID:25549079

  7. Review: two-photon scanning systems for clinical high resolution in vivo tissue imaging

    NASA Astrophysics Data System (ADS)

    König, K.; Müller, J.; Höfer, M.; Müller, C.; Weinigel, M.; Bückle, R.; Elsner, P.; Kaatz, M.; Messerschmidt, B.

    2008-02-01

    The femtosecond laser multiphoton tomograph DermaInspect as well as high NA two-photon GRIN microendoscopes for in vivo tomography of human skin have been used to detect malignant melanoma as well as to study the diffusion and intradermal accumulation of topically applied cosmetical and pharmaceutical components. So far, more than 500 patients and volunteers in Europe, Australia, and Asia have been investigated with this unique tomograph. Near infrared 80 MHz picojoule femtosecond laser pulses were employed to excite endogenous fluorophores such as NAD(P)H, flavoproteins, melanin, and elastin as well as fluorescent components of a variety of ointments via a twophoton excitation process. In addition, collagen has been imaged by second harmonic generation. Using a two-PMT detection system, the ratio of elastin to collagen was determined during optical sectioning. A high submicron spatial resolution and 50 picosecond temporal resolution was achieved using galvoscan mirrors and piezodriven focusing optics as well as a time-correlated single photon counting module with a fast microchannel plate detector and fast photomultipliers. Individual intratissue cells, mitochondria, melanosomes, and the morphology of the nuclei as well as extracellular matrix elements could be clearly visualized due to molecular imaging and the calculation of fluorescence lifetime images. Nanoparticles and intratissue drugs have been detected non-invasively, in situ and over a period of up to 3 months. In addition, hydration effects and UV effects were studied by monitoring modifications of cellular morphology and autofluorescence. The system was used to observe the diffusion through the stratum corneum and the accumulation and release of functionalized nanoparticles along hair shafts and epidermal ridges. The DermaInspect been also employed to gain information on skin age and wound healing in patients with ulcers. Novel developments include a galvo/piezo-scan driven flexible articulated arm as

  8. Characterizing a proton beam scanning system for Monte Carlo dose calculation in patients

    NASA Astrophysics Data System (ADS)

    Grassberger, C.; Lomax, Anthony; Paganetti, H.

    2015-01-01

    The presented work has two goals. First, to demonstrate the feasibility of accurately characterizing a proton radiation field at treatment head exit for Monte Carlo dose calculation of active scanning patient treatments. Second, to show that this characterization can be done based on measured depth dose curves and spot size alone, without consideration of the exact treatment head delivery system. This is demonstrated through calibration of a Monte Carlo code to the specific beam lines of two institutions, Massachusetts General Hospital (MGH) and Paul Scherrer Institute (PSI). Comparison of simulations modeling the full treatment head at MGH to ones employing a parameterized phase space of protons at treatment head exit reveals the adequacy of the method for patient simulations. The secondary particle production in the treatment head is typically below 0.2% of primary fluence, except for low-energy electrons (<0.6 MeV for 230 MeV protons), whose contribution to skin dose is negligible. However, there is significant difference between the two methods in the low-dose penumbra, making full treatment head simulations necessary to study out-of-field effects such as secondary cancer induction. To calibrate the Monte Carlo code to measurements in a water phantom, we use an analytical Bragg peak model to extract the range-dependent energy spread at the two institutions, as this quantity is usually not available through measurements. Comparison of the measured with the simulated depth dose curves demonstrates agreement within 0.5 mm over the entire energy range. Subsequently, we simulate three patient treatments with varying anatomical complexity (liver, head and neck and lung) to give an example how this approach can be employed to investigate site-specific discrepancies between treatment planning system and Monte Carlo simulations.

  9. A new centering method of the measuring probe for spiral scanning-based surface profile measurement systems

    NASA Astrophysics Data System (ADS)

    Du, Hui-Lin; Zeng, Pei-Yang; Ju, Bing-Feng; Zhou, Zhao-Zhong; Xu, Shaoning; Sun, Anyu

    2017-02-01

    Spiral scanning is a high-efficiency scanning mode for surface profile measurement systems. The most important priority to realize the spiral scanning mode is to accurately align the measuring probe with the rotational centre of the spindle. This paper proposes a novel centre alignment method of the measuring probe, which is considered to be suitable for any type of spiral scanning surface measurement systems. The proposed method, which only needs a tilted flat mirror as the artefact, makes the time-consuming centre alignment process of the measuring probe become much easier and faster. The operational steps of the proposed method are presented. Experiments have also been carried out based on a self-developed optical profiler with spiral scanning operation to verity the feasibility of the proposed method. The experimental results show that the proposed method is capable of conducting a fast alignment (only takes 3 min) while maintaining a high alignment accuracy. Evaluation of the alignment accuracy shows that the centering error is less than 10 µm on the mechanical guide rail stage and about 1.7 µm on the air-bearing stage.

  10. TeraScanXR: a high sensitivity and throughput photomask inspection system

    NASA Astrophysics Data System (ADS)

    Mu, Bo; Dayal, Aditya; Goonesekera, Arosha; Lim, Phillip; Chen, Chunlin; Liu, Po; Yeung, Kevin; Pinto, Becky; Broadbent, Bill; Inderhees, Gregg

    2009-04-01

    As optical lithography progresses towards 32nm node and beyond, shrinking feature size on photomasks and growing database size provides new challenges for reticle manufacture and inspection. The new TeraScanXR extends the inspection capability and sensitivity of the TeraScanHR to meet these challenges. TeraScanXR launches a new function that can dynamically adjust defect sensitivities based on the image contrast (MEEF) -- applying higher sensitivity to dense pattern regions, and lower sensitivity to sparse regions which are lithographically less significant. The defect sensitivity of TeraScanXR for Die-to-Die (DD) and Die-to-Database (DDB) inspection mode is improved by 20-30%, compared with TeraScanHR. In addition, a new capability is introduced to increase sensitivity specifically to long CD defects. Without sacrificing the inspection performance, the new TeraScanXR boosts the inspection throughput by 35%- 75% (depending upon the inspection mode) and the dataprep speed by 6X, as well as the capability to process 0.5-1 Terabyte preps for DDB inspection.

  11. Analysis on the lateral resolution of optical scanning holography system based on random phase encoding using restricted pupils

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Hu, Jian-Ping; Yuan, Sheng; Xie, Jian; Guo, Xue-Fan; Zhang, Luo-Zhi; Wan, Dao-Ming; Hu, You-Jun; Zhou, Xin

    2014-05-01

    In this paper, we analyze the point spread function of optical scanning holography (OSH) system based on random phase encoding (RPE-OSH) with restricted pupils and compare the lateral resolution of RPE-OSH system with the one of conventional OSH system by the definition of Rayleigh criterion. The results show that the main lobe width of RPE-OSH system is much narrower than that of the conventional OSH system under the same conditions; thus, the reconstructed image in RPE-OSH system has a higher lateral resolution and reserves more detailed information. This conclusion is verified by numerical simulations of the Cymbella cymbiformis image reconstruction.

  12. Systematic analyses of vibration noise of a vibration isolation system for high-resolution scanning tunneling microscopes.

    PubMed

    Iwaya, Katsuya; Shimizu, Ryota; Hashizume, Tomihiro; Hitosugi, Taro

    2011-08-01

    We designed and constructed an effective vibration isolation system for stable scanning tunneling microscopy measurements using a separate foundation and two vibration isolation stages (i.e., a combination of passive and active vibration isolation dampers). Systematic analyses of vibration data along the horizontal and vertical directions are present, including the vibration transfer functions of each stage and the overall vibration isolation system. To demonstrate the performance of the system, tunneling current noise measurements are conducted with and without the vibration isolation. Combining passive and active vibration isolation dampers successfully removes most of the vibration noise in the tunneling current up to 100 Hz. These comprehensive vibration noise data, along with details of the entire system, can be used to establish a clear guideline for building an effective vibration isolation system for various scanning probe microscopes and electron microscopes.

  13. Geomorphic features off southern California as seen by GLORIA side-scan sonar system

    SciTech Connect

    Edwards, B.D.; Field, M.E.; Carlson, P.R.; Kenyon, N.H.

    1985-02-01

    Approximately 165,000 km/sup 2/ of the sea floor off southern California was mapped during May 1984, as part of a USGS/IOS cooperative program to study the newly proclaimed Exclusive Economic Zone (EEZ) of the US Pacific margin. The area was insonified using the Geological Long-Range Inclined Asdic (GLORIA), a long-range side-scan sonar system. Images were corrected for water-column velocity anomalies, for along-track distortions caused by acoustic ray travel paths. A photomosaic of the overlapping sonographs has been compiled at a scale of 1:375,000. The basins of the inner California continental borderland are characterized by both sinuous channel and fan complexes and by feathery acoustic patterns indicating active sediment transport. In contrast, outer borderland basins appear to be more sediment starved, exhibit large areas of sediment failure, and show significant structural influence. West of Patton Escarpment, the sonographs are dominated by acoustic patterns showing volcanic ridges and seamounts and by deposits of the Monterey and Arguello fans. Arguello fan, for example, exhibits multiple sinuous channels that have transported sediment 60 km south from the canyon mouth. These channels coalesce into a single 100-km long, westward-meandering channel that terminates in a 600-m deep box canyon. A zone of sediment failure is identifiable on the north levee of an upper fan channel. Tectonic trends associated with oceanic basement are highlighted by the terminus of the west-trending Murray Fracture Zone and by the prevailing northeast trend of volcanic ridge and seamount chains.

  14. Damage identification of beam structures using free response shapes obtained by use of a continuously scanning laser Doppler vibrometer system

    NASA Astrophysics Data System (ADS)

    Xu, Y. F.; Chen, Da-Ming; Zhu, W. D.

    2017-08-01

    Spatially dense operating deflection shapes and mode shapes can be rapidly obtained by use of a continuously scanning laser Doppler vibrometer (CSLDV) system, which sweeps its laser spot over a vibrating structure surface. This paper introduces a new type of vibration shapes called a free response shape (FRS) that can be obtained by use of a CSLDV system, and a new damage identification methodology using FRSs is developed for beam structures. An analytical expression of FRSs of a damped beam structure is derived, and FRSs from the analytical expression compare well with those from a finite element model. In the damage identification methodology, a free-response damage index (FRDI) is proposed, and damage regions can be identified near neighborhoods with consistently high values of FRDIs associated with different modes; an auxiliary FRDI is defined to assist identification of the neighborhoods. A FRDI associated with a mode consists of differences between curvatures of FRSs associated with the mode in a number of half-scan periods of a CSLDV system and those from polynomials that fit the FRSs with properly determined orders. A convergence index is proposed to determine the proper order of a polynomial fit. One advantage of the methodology is that the FRDI does not require any baseline information of an undamaged beam structure, if it is geometrically smooth and made of materials that have no stiffness and mass discontinuities. Another advantage is that FRDIs associated with multiple modes can be obtained using free response of a beam structure measured by a CSLDV system in one scan. The number of half-scan periods for calculation of the FRDI associated with a mode can be determined by use of the short-time Fourier transform. The proposed methodology was numerically and experimentally applied to identify damage in beam structures; effects of the scan frequency of a CSLDV system on qualities of obtained FRSs were experimentally investigated.

  15. Design of a scanning gate microscope for mesoscopic electron systems in a cryogen-free dilution refrigerator.

    PubMed

    Pelliccione, M; Sciambi, A; Bartel, J; Keller, A J; Goldhaber-Gordon, D

    2013-03-01

    We report on our design of a scanning gate microscope housed in a cryogen-free dilution refrigerator with a base temperature of 15 mK. The recent increase in efficiency of pulse tube cryocoolers has made cryogen-free systems popular in recent years. However, this new style of cryostat presents challenges for performing scanning probe measurements, mainly as a result of the vibrations introduced by the cryocooler. We demonstrate scanning with root-mean-square vibrations of 0.8 nm at 3 K and 2.1 nm at 15 mK in a 1 kHz bandwidth with our design. Using Coulomb blockade thermometry on a GaAs/AlGaAs gate-defined quantum dot, we demonstrate an electron temperature of 45 mK.

  16. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

    NASA Astrophysics Data System (ADS)

    Yoshida, J.; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M. K.; Theint, A. M. M.; Tint, K. T.

    2017-03-01

    A new scanning system named "Vertex picker" has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

  17. Development of the scanning system to detect the concentration of oxy- and deoxy-hemoglobin by tracking the head

    NASA Astrophysics Data System (ADS)

    Ko, Woo Seok; Darwish, Naser; Gratton, Enrico; Kim, Soo Hyun

    2005-04-01

    We measure the concentration of oxy-, deoxy- and total hemoglobin by using the frequency-domain, near-infrared spectroscopy(NIRS) scanner. It is a non-invasive instrument that can provide real-time measurements of the changes in concentration. It can provide a diagnostic tool for the study of the brain in infants and children. However, it is difficult to apply it to the baby's head because of the contact of the probe on the soft baby's head. Therefore, we suggest the NIRS scanning system that can track the baby' head movement and detect NIRS parameters on the same position of the head. This system has three key components. The vision system performs the pattern matching for tracking the head by using the normalized cross correlation method with the target as a cross-line on the head during the diagnostic experiment. We can use the change of the position of the baby's head to re-target the light by the scanning system that uses four laser sources, a wavelength selector, and an x-y scanner. The detector system analyzes the resulting signal from the head using the diffusion model. Therefore, NIRS scanning system can provide a diagnostic tool to measure the changes of the NIRS parameters for the study of the baby's brain.

  18. Bone Scan

    MedlinePlus

    ... Mayo Clinic Staff A bone scan is a nuclear imaging test that helps diagnose and track several ... you're nursing. A bone scan is a nuclear imaging procedure. In nuclear imaging, tiny amounts of ...

  19. CT Scans

    MedlinePlus

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  20. Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems

    EPA Science Inventory

    The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, electro-scan (FELL-41), and a multi-sens...

  1. Surface and subsurface inspection of food safety and quality using a line-scan Raman system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents a line-scan Raman platform for food safety and quality research, which can be configured for Raman chemical imaging (RCI) mode for surface inspection and spatially offset Raman spectroscopy (SORS) mode for subsurface inspection. In the RCI mode, macro-scale imaging was achieved u...

  2. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    SciTech Connect

    Zaka, Fowzia

    2016-03-21

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  3. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    SciTech Connect

    Zaka, Fowzia

    2016-03-08

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  4. Use of Slow-Scan Television Systems in Telemedicine, Distance Education, Government, and Industrial Applications.

    ERIC Educational Resources Information Center

    Southworth, Glen

    Reducing the costs of teaching by television through slow-scan methods is discussed. Conventional television is costly to use, largely because the wide-band communications circuits required are in limited supply. One technical answer is bandwidth compression to fit an image into less spectrum space. A simpler and far less costly answer is to…

  5. Analysis of the Possibilities of Using Low-Cost Scanning System in 3d Modeling

    NASA Astrophysics Data System (ADS)

    Kedzierski, M.; Wierzbickia, D.; Fryskowska, A.; Chlebowska, B.

    2016-06-01

    The laser scanning technique is still a very popular and fast growing method of obtaining information on modeling 3D objects. The use of low-cost miniature scanners creates new opportunities for small objects of 3D modeling based on point clouds acquired from the scan. The same, the development of accuracy and methods of automatic processing of this data type is noticeable. The article presents methods of collecting raw datasets in the form of a point-cloud using a low-cost ground-based laser scanner FabScan. As part of the research work 3D scanner from an open source FabLab project was constructed. In addition, the results for the analysis of the geometry of the point clouds obtained by using a low-cost laser scanner were presented. Also, some analysis of collecting data of different structures (made of various materials such as: glass, wood, paper, gum, plastic, plaster, ceramics, stoneware clay etc. and of different shapes: oval and similar to oval and prism shaped) have been done. The article presents two methods used for analysis: the first one - visual (general comparison between the 3D model and the real object) and the second one - comparative method (comparison between measurements on models and scanned objects using the mean error of a single sample of observations). The analysis showed, that the low-budget ground-based laser scanner FabScan has difficulties with collecting data of non-oval objects. Items built of glass painted black also caused problems for the scanner. In addition, the more details scanned object contains, the lower the accuracy of the collected point-cloud is. Nevertheless, the accuracy of collected data (using oval-straight shaped objects) is satisfactory. The accuracy, in this case, fluctuates between ± 0,4 mm and ± 1,0 mm whereas when using more detailed objects or a rectangular shaped prism the accuracy is much more lower, between 2,9 mm and ± 9,0 mm. Finally, the publication presents the possibility (for the future expansion of

  6. Range 7 Scanner Integration with PaR Robot Scanning System

    NASA Technical Reports Server (NTRS)

    Schuler, Jason; Burns, Bradley; Carlson, Jeffrey; Minich, Mark

    2011-01-01

    An interface bracket and coordinate transformation matrices were designed to allow the Range 7 scanner to be mounted on the PaR Robot detector arm for scanning the heat shield or other object placed in the test cell. A process was designed for using Rapid Form XOR to stitch data from multiple scans together to provide an accurate 3D model of the object scanned. An accurate model was required for the design and verification of an existing heat shield. The large physical size and complex shape of the heat shield does not allow for direct measurement of certain features in relation to other features. Any imaging devices capable of imaging the entire heat shield in its entirety suffers a reduced resolution and cannot image sections that are blocked from view. Prior methods involved tools such as commercial measurement arms, taking images with cameras, then performing manual measurements. These prior methods were tedious and could not provide a 3D model of the object being scanned, and were typically limited to a few tens of measurement points at prominent locations. Integration of the scanner with the robot allows for large complex objects to be scanned at high resolution, and for 3D Computer Aided Design (CAD) models to be generated for verification of items to the original design, and to generate models of previously undocumented items. The main components are the mounting bracket for the scanner to the robot and the coordinate transformation matrices used for stitching the scanner data into a 3D model. The steps involve mounting the interface bracket to the robot's detector arm, mounting the scanner to the bracket, and then scanning sections of the object and recording the location of the tool tip (in this case the center of the scanner's focal point). A novel feature is the ability to stitch images together by coordinates instead of requiring each scan data set to have overlapping identifiable features. This setup allows models of complex objects to be developed

  7. SCANS (Shipping Cask ANalysis System) a microcomputer-based analysis system for shipping cask design review: User`s manual to Version 3a. Volume 1, Revision 2

    SciTech Connect

    Mok, G.C.; Thomas, G.R.; Gerhard, M.A.; Trummer, D.J.; Johnson, G.L.

    1998-03-01

    SCANS (Shipping Cask ANalysis System) is a microcomputer-based system of computer programs and databases developed at the Lawrence Livermore National Laboratory (LLNL) for evaluating safety analysis reports on spent fuel shipping casks. SCANS is an easy-to-use system that calculates the global response to impact loads, pressure loads and thermal conditions, providing reviewers with an independent check on analyses submitted by licensees. SCANS is based on microcomputers compatible with the IBM-PC family of computers. The system is composed of a series of menus, input programs, cask analysis programs, and output display programs. All data is entered through fill-in-the-blank input screens that contain descriptive data requests. Analysis options are based on regulatory cases described in the Code of Federal Regulations 10 CFR 71 and Regulatory Guides published by the US Nuclear Regulatory Commission in 1977 and 1978.

  8. HIGH RESOLUTION AND FAST SCANNING SQUID BASED NON-DESTRUCTIVE INSPECTION SYSTEM OF NIOBIUM SHEETS FOR SRF CAVITIES

    SciTech Connect

    SHU, QUAN-SHENG

    2008-06-08

    Applications in high energy physics accelerators and other fields require the use of thousands of superconducting RF (SRF) cavities that are made of high purity Nb material and the purity of niobium is critical for these cavities to reach the highest accelerating fields. Tantalum is the most prolific of metal inclusions, which can cause thermal breakdown and prevent the cavities from reaching their theoretical performance limits of 45-50 MV/m, and DOE Labs are searching for a technology that could detect small impurities in superconducting Nb sheets reaching the highest possible accelerating fields. The proposed innovative SQUID-based Nondestructive system can scan Niobium sheets used in the manufacturing of SRF cavities with both high speed and high resolution. A highly sensitive SQUID system with a gradiometer probe, non-magnetic dewar, data acquisition system, and a scanning system will be developed for fast detection of impurities in planar Nb sheets. In phase I, we will modify our existing SQUID-based eddy current system to detect 100 micron size Ta defects and a great effort will focus on achieving fast scanning of a large number of niobium sheets in a shorter time and with reasonable resolution. An older system operated by moving the sample 1 mm, stopping and waiting for 1-2 seconds, then activating a measurement by the SQUID after the short settle time is modified. A preliminary designed and implemented a SQUID scanning system that is fast and is capable of scanning a 30 cm x 30 cm Nb sheet in 15 minutes by continuously moving the table at speeds up to 10 mm/s while activating the SQUID at 1mm interval is modified and reached the Phase I goal of 100mm resolution. We have successfully demonstrated the feasibility that a fast speed SQUID scanner without sacrificing the resolution of detection can be done, and a data acquisition and analysis system is also preliminary developed. The SQUID based scanner will help reach the highest accelerating field in SRF

  9. Development of kinematic 3D laser scanning system for indoor mapping and as-built BIM using constrained SLAM.

    PubMed

    Jung, Jaehoon; Yoon, Sanghyun; Ju, Sungha; Heo, Joon

    2015-10-16

    The growing interest and use of indoor mapping is driving a demand for improved data-acquisition facility, efficiency and productivity in the era of the Building Information Model (BIM). The conventional static laser scanning method suffers from some limitations on its operability in complex indoor environments, due to the presence of occlusions. Full scanning of indoor spaces without loss of information requires that surveyors change the scanner position many times, which incurs extra work for registration of each scanned point cloud. Alternatively, a kinematic 3D laser scanning system, proposed herein, uses line-feature-based Simultaneous Localization and Mapping (SLAM) technique for continuous mapping. Moreover, to reduce the uncertainty of line-feature extraction, we incorporated constrained adjustment based on an assumption made with respect to typical indoor environments: that the main structures are formed of parallel or orthogonal line features. The superiority of the proposed constrained adjustment is its reduction for uncertainties of the adjusted lines, leading to successful data association process. In the present study, kinematic scanning with and without constrained adjustment were comparatively evaluated in two test sites, and the results confirmed the effectiveness of the proposed system. The accuracy of the 3D mapping result was additionally evaluated by comparison with the reference points acquired by a total station: the Euclidean average distance error was 0.034 m for the seminar room and 0.043 m for the corridor, which satisfied the error tolerance for point cloud acquisition (0.051 m) according to the guidelines of the General Services Administration for BIM accuracy.

  10. Development of Kinematic 3D Laser Scanning System for Indoor Mapping and As-Built BIM Using Constrained SLAM

    PubMed Central

    Jung, Jaehoon; Yoon, Sanghyun; Ju, Sungha; Heo, Joon

    2015-01-01

    The growing interest and use of indoor mapping is driving a demand for improved data-acquisition facility, efficiency and productivity in the era of the Building Information Model (BIM). The conventional static laser scanning method suffers from some limitations on its operability in complex indoor environments, due to the presence of occlusions. Full scanning of indoor spaces without loss of information requires that surveyors change the scanner position many times, which incurs extra work for registration of each scanned point cloud. Alternatively, a kinematic 3D laser scanning system, proposed herein, uses line-feature-based Simultaneous Localization and Mapping (SLAM) technique for continuous mapping. Moreover, to reduce the uncertainty of line-feature extraction, we incorporated constrained adjustment based on an assumption made with respect to typical indoor environments: that the main structures are formed of parallel or orthogonal line features. The superiority of the proposed constrained adjustment is its reduction for uncertainties of the adjusted lines, leading to successful data association process. In the present study, kinematic scanning with and without constrained adjustment were comparatively evaluated in two test sites, and the results confirmed the effectiveness of the proposed system. The accuracy of the 3D mapping result was additionally evaluated by comparison with the reference points acquired by a total station: the Euclidean average distance error was 0.034 m for the seminar room and 0.043 m for the corridor, which satisfied the error tolerance for point cloud acquisition (0.051 m) according to the guidelines of the General Services Administration for BIM accuracy. PMID:26501292

  11. A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system

    PubMed Central

    Patil, Chetan A.; Arrasmith, Christopher L.; Mackanos, Mark A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2012-01-01

    Confocal reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which combines laser scanning confocal reflectance imaging and confocal Raman spectroscopy into a compact handheld probe that is capable of high-resolution imaging and spectroscopy in a variety of settings. The compact size of the probe is largely due to the use of a MEMS mirror for beam scanning. The probe is capable of axial resolutions of up to 4 μm for the confocal imaging channel and 10 μm for the confocal Raman spectroscopy channel. Here, we report instrument design, characterize optical performance, and provide images and spectra from normal skin to demonstrate the instrument’s capabilities for clinical diagnostics. PMID:22435097

  12. A pipette-based calibration system for fast-scan cyclic voltammetry with fast response times.

    PubMed

    Ramsson, Eric S

    2016-01-01

    Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique that utilizes the oxidation and/or reduction of an analyte of interest to infer rapid changes in concentrations. In order to calibrate the resulting oxidative or reductive current, known concentrations of an analyte must be introduced under controlled settings. Here, I describe a simple and cost-effective method, using a Petri dish and pipettes, for the calibration of carbon fiber microelectrodes (CFMs) using FSCV.

  13. Wide area scanning system and carbon microbeams at the external microbeam facility of the INFN LABEC laboratory in Florence

    NASA Astrophysics Data System (ADS)

    Giuntini, L.; Massi, M.; Calusi, S.; Castelli, L.; Carraresi, L.; Fedi, M. E.; Gelli, N.; Liccioli, L.; Mandò, P. A.; Mazzinghi, A.; Palla, L.; Romano, F. P.; Ruberto, C.; Taccetti, F.

    2015-04-01

    Recently, developments have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence. A new system for mechanical sample scanning was implemented. This system allows us to acquire large maps (up to 20 × 20 cm2), of great interest in the Cultural Heritage field. In parallel, the possibility of using carbon microbeams for experiments, such as, for example, ion beam modification of materials and MeV Secondary Ion Mass Spectrometry, has been investigated. As a test application, Particle Induced X-ray Emission with carbon microbeams has been performed on a lapis lazuli stone. First results for both wide area imaging and external carbon microbeams are briefly reported.

  14. Closed-loop control of a 2-D mems micromirror with sidewall electrodes for a laser scanning microscope system

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Chen, Albert; Jie Sun, Wei; Sun, Zhen Dong; Yeow, John TW

    2016-01-01

    This article presents the development and implementation of a robust nonlinear control scheme for a 2-D micromirror-based laser scanning microscope system. The presented control scheme, built around sliding mode control approach and augmented an adaptive algorithm, is proposed to improve the tracking accuracy in presence of cross-axis effect. The closed-loop controlled imaging system is developed through integrating a 2-D micromirror with sidewall electrodes (SW), a laser source, NI field-programmable gate array (FPGA) hardware, the optics, position sensing detector (PSD) and photo detector (PD). The experimental results demonstrated that the proposed scheme is able to achieve accurate tracking of a reference triangular signal. Compared with open-loop control, the scanning performance is significantly improved, and a better 2-D image is obtained using the micromirror with the proposed scheme.

  15. Continuous wave synthetic low-coherence wind sensing Lidar: motionless measurement system with subsequent numerical range scanning.

    PubMed

    Brinkmeyer, Ernst; Waterholter, Thomas

    2013-01-28

    A continuous wave (CW) Lidar system for detection of scattering from atmospheric aerosol particles is presented which is useful in particular for remote sensing of wind velocities. It is based on a low-coherence interferometric setup powered by a synthetic broadband laser source with Gaussian power density spectrum. The laser bandwidth is electronically adjustable and determines the spatial resolution which is independent of range. The Lidar system has no moving parts. The location to be resolved can be shifted numerically after the measurement meaning that a single measurement already contains the full range information. The features of constant resolution and numerical range scanning are in sharp contrast to ordinary CW Lidar systems.

  16. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    SciTech Connect

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  17. A study program on large aperture electronic scanning phased array antennas for the shuttle imaging microwave system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Fundamental phased array theory and performance parameters are discussed in terms of their application to microwave radiometry, and four scanning phased arrays representing current examples of state-of-the-art phased array technology are evaluated for potential use as components of the multispectral antenna system for the space shuttle imaging microwave system (SIMS). A discussion of problem areas, both in performance and fabrication is included, with extrapolations of performance characteristics for phased array antennas of increased sizes up to 20 m by 20 m. The possibility of interlacing two or more phased arrays to achieve a multifrequency aperture is considered, and, finally, a specific antenna system is recommended for use with SIMS.

  18. Low-temperature scanning tunneling microscopy and transport measurements on adsorbate-induced two-dimensional electron systems

    SciTech Connect

    Masutomi, Ryuichi; Triyama, Naotaka; Okamoto, Tohru

    2013-12-04

    We have performed not only magnetotransport measurements on two-dimensional electron systems (2DESs) formed at the cleaved surfaces of p-InAs but also observations of the surface morphology of the adsorbate atoms, which induced the 2DES at the surfaces of narrow band-gap semiconductors, with use of a scanning tunneling microscopy. The electron density of the 2DESs is compared to the atomic density of the isolated Ag adatoms on InAs surfaces.

  19. Development of lightweight structural health monitoring systems for aerospace applications

    NASA Astrophysics Data System (ADS)

    Pearson, Matthew

    This thesis investigates the development of structural health monitoring systems (SHM) for aerospace applications. The work focuses on each aspect of a SHM system covering novel transducer technologies and damage detection techniques to detect and locate damage in metallic and composite structures. Secondly the potential of energy harvesting and power arrangement methodologies to provide a stable power source is assessed. Finally culminating in the realisation of smart SHM structures. 1. Transducer Technology A thorough experimental study of low profile, low weight novel transducers not normally used for acoustic emission (AE) and acousto-ultrasonics (AU) damage detection was conducted. This included assessment of their performance when exposed to aircraft environments and feasibility of embedding these transducers in composites specimens in order to realise smart structures. 2. Damage Detection An extensive experimental programme into damage detection utilising AE and AU were conducted in both composites and metallic structures. These techniques were used to assess different damage mechanism within these materials. The same transducers were used for novel AE location techniques coupled with AU similarity assessment to successfully detect and locate damage in a variety of structures. 3. Energy Harvesting and Power Management Experimental investigations and numerical simulations were undertaken to assess the power generation levels of piezoelectric and thermoelectric generators for typical vibration and temperature differentials which exist in the aerospace environment. Furthermore a power management system was assessed to demonstrate the ability of the system to take the varying nature of the input power and condition it to a stable power source for a system. 4. Smart Structures The research conducted is brought together into a smart carbon fibre wing showcasing the novel embedded transducers for AE and AU damage detection and location, as well as vibration energy

  20. Navigation for space shuttle approach and landing using an inertial navigation system augmented by data from a precision ranging system or a microwave scan beam landing guidance system

    NASA Technical Reports Server (NTRS)

    Mcgee, L. A.; Smith, G. L.; Hegarty, D. M.; Merrick, R. B.; Carson, T. M.; Schmidt, S. F.

    1970-01-01

    A preliminary study has been made of the navigation performance which might be achieved for the high cross-range space shuttle orbiter during final approach and landing by using an optimally augmented inertial navigation system. Computed navigation accuracies are presented for an on-board inertial navigation system augmented (by means of an optimal filter algorithm) with data from two different ground navigation aids; a precision ranging system and a microwave scanning beam landing guidance system. These results show that augmentation with either type of ground navigation aid is capable of providing a navigation performance at touchdown which should be adequate for the space shuttle. In addition, adequate navigation performance for space shuttle landing is obtainable from the precision ranging system even with a complete dropout of precision range measurements as much as 100 seconds before touchdown.

  1. Mobile gamma-ray scanning system for detecting radiation anomalies associated with /sup 226/Ra-bearing materials

    SciTech Connect

    Myrick, T.E.; Blair, M.S.; Doane, R.W.; Goldsmith, W.A.

    1982-11-01

    A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the Department of Energy's remedial action survey programs. The unit consists of a NaI(T1) detection system housed in a specially-equipped van. The system is operator controlled through an on-board mini-computer, with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided by a floppy disk system. Multichannel analysis capabilities are included for qualitative radionuclide identification. A /sup 226/Ra-specific algorithm is employed to identify locations containing residual radium-bearing materials. This report presents the details of the system description, software development, and scanning methods utilized with the ORNL system. Laboratory calibration and field testing have established the system sensitivity, field of view, and other performance characteristics, the results of which are also presented. Documentation of the instrumentation and computer programs are included.

  2. Study of the KNO3-Al2O3 system by differential scanning calorimetry

    NASA Astrophysics Data System (ADS)

    Amirov, A. M.; Gafurov, M. M.; Rabadanov, K. Sh.

    2016-09-01

    The structural and the thermodynamic properties of potassium nitrate KNO3 and its composites with nanosized aluminum oxide Al2O3 have been studied by differential scanning calorimetry. It has been found that an amorphous phase forms in composites (1- x)KNO3- x Al2O3. The thermal effect corresponding to this phase has been observed at 316°C. It has been found that the phase transition heats of potassium nitrate decreased as the aluminum oxide fraction increased.

  3. An excitation wavelength-scanning spectral imaging system for preclinical imaging

    NASA Astrophysics Data System (ADS)

    Leavesley, Silas; Jiang, Yanan; Patsekin, Valery; Rajwa, Bartek; Robinson, J. Paul

    2008-02-01

    Small-animal fluorescence imaging is a rapidly growing field, driven by applications in cancer detection and pharmaceutical therapies. However, the practical use of this imaging technology is limited by image-quality issues related to autofluorescence background from animal tissues, as well as attenuation of the fluorescence signal due to scatter and absorption. To combat these problems, spectral imaging and analysis techniques are being employed to separate the fluorescence signal from background autofluorescence. To date, these technologies have focused on detecting the fluorescence emission spectrum at a fixed excitation wavelength. We present an alternative to this technique, an imaging spectrometer that detects the fluorescence excitation spectrum at a fixed emission wavelength. The advantages of this approach include increased available information for discrimination of fluorescent dyes, decreased optical radiation dose to the animal, and ability to scan a continuous wavelength range instead of discrete wavelength sampling. This excitation-scanning imager utilizes an acousto-optic tunable filter (AOTF), with supporting optics, to scan the excitation spectrum. Advanced image acquisition and analysis software has also been developed for classification and unmixing of the spectral image sets. Filtering has been implemented in a single-pass configuration with a bandwidth (full width at half maximum) of 16nm at 550nm central diffracted wavelength. We have characterized AOTF filtering over a wide range of incident light angles, much wider than has been previously reported in the literature, and we show how changes in incident light angle can be used to attenuate AOTF side lobes and alter bandwidth. A new parameter, in-band to out-of-band ratio, was defined to assess the quality of the filtered excitation light. Additional parameters were measured to allow objective characterization of the AOTF and the imager as a whole. This is necessary for comparing the

  4. 0.7-NA DUV step-and-scan system for 150-nm imaging with improved overlay

    NASA Astrophysics Data System (ADS)

    van Schoot, Jan B.; Bornebroek, Frank; Suddendorf, Manfred; Mulder, Melchior; van der Spek, Jeroen; Stoeten, Jan; Hunter, Adolph; Ruemmer, Peter

    1999-07-01

    To extend KrF lithography below the 180nm SIA design rule node in manufacturing, an advanced DUV step and scan system utilizing a lens with an NA up to 0.7 will be required to provide sufficient process latitude. Towards the SIA's 150nm design rule node, manufacturing challenges for 248nm lithography include contact hole printing, iso-dense bias control and adequate across the field CD uniformity. All will benefit from higher NA lenses. In the paper, result obtained on a PAS 5500/700B DUV Step and Scan system are presented. The system design is based on the PAS 5500/500 with a new 0.7NA Starlith lens, AERIAL II illuminator and ATHENA advanced alignment system. Imaging of dense and isolated lines at 180nm, 150nm and below as well as 180nm and 160nm contact holes is shown. In addition to imaging performance, image plane deviation, system distortion fingerprints, single-machine overlay and multiple-machine matching results are shown. Using the ATHENA alignment system, alignment reproducibility as well as overlay result on CMP wafers will be shown. It is concluded that this exposure tool is capable of delivering imaging and overlay performance required for mass production at the 150nm design rule node, with potential for R and D applications beyond.

  5. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System

    PubMed Central

    Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

    2016-01-01

    This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths. PMID:27999252

  6. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System.

    PubMed

    Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

    2016-12-16

    This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

  7. Precision large field scanning system for high numerical aperture lenses and application to femtosecond micromachining of ophthalmic materials.

    PubMed

    Brooks, D R; Brown, N S; Savage, D E; Wang, C; Knox, W H; Ellis, J D

    2014-06-01

    A precision, large stroke (nearly 1 cm) scanning system was designed, built, and calibrated for micromachining of ophthalmic materials including hydrogels and cornea (excised and in vivo). This system comprises a flexure stage with an attached objective on stacked vertical and horizontal translation stages. This paper outlines the design process leading to our most current version including the specifications that were used in the design and the drawbacks of other methods that were previously used. Initial measurements of the current version are also given. The current flexure was measured to have a 27 Hz natural frequency with no load.

  8. Renal scan

    MedlinePlus

    ... and urinate often to help remove the radioactive material from the body. How to Prepare for the Test Tell your health care provider if you take ... drink additional fluids before the scan. How the Test will ... into the vein. However, you will not feel the radioactive material. The scanning table may be hard and cold. ...

  9. Lithographic performance of a dual-stage 0.93NA ArF step and scan system

    NASA Astrophysics Data System (ADS)

    Rubingh, Rian; Moers, Marco; Suddendorf, Manfred; Vanoppen, Peter; Kisteman, Aernout; Thier, Michael; Blahnik, Vladan; Piper, Eckhard

    2005-05-01

    This paper presents lithographic performance results obtained from the newest member of ASML's TWINSCAN platform-based step & scan systems, the TWINSCAN XT:1400. The system has been designed to meet the semiconductor industry's aggressive requirements on CD control, overlay and productivity at and below the 65 nm node. This dual stage 193 nm lithographic system combines the worlds highest NA, with excellent overlay and CD control at high throughput on both 200 and 300 mm wafers and is intended for use in volume production environments. Advances in stage technology have enabled further extension of stage scan speeds and an associated increase in tool productivity. However, maximizing the number of yielding die per day also requires stringent overlay and Critical Dimension (CD) control. Tight CD control at improved resolution is supported by the Starlith 1400 projection lens and the extended sigma capabilities of the new AERIAL-E illumination system. Focus control is improved in line with the stringent requirements posed by low-k1 imaging applications, taking full advantage of the unique dual-stage TWINSCAN system architecture.

  10. Annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography of polymer systems.

    PubMed

    Lu, Kangbo; Sourty, Erwan; Loos, Joachim

    2010-08-01

    We have utilized bright-field conventional transmission electron microscopy tomography and annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography to characterize a well-defined carbon black (CB)-filled polymer nanocomposite with known CB volume concentration. For both imaging methods, contrast can be generated between the CB and the surrounding polymer matrix. The involved contrast mechanisms, in particular for ADF-STEM, will be discussed in detail. The obtained volume reconstructions were analysed and the CB volume concentrations were carefully determined from the reconstructed data. For both imaging modes, the measured CB volume concentrations are substantially different and only quantification based on the ADF-STEM data revealed about the same value as the known CB loading. Moreover, when applying low-convergence angles for imaging ADF-STEM tomography, data can be obtained of micrometre-thick samples.

  11. Assessment of DNA replication in central nervous system by Laser Scanning Cytometry

    NASA Astrophysics Data System (ADS)

    Lenz, Dominik; Mosch, Birgit; Bocsi, Jozsef; Arendt, Thomas; Tárnok, Attila

    2004-07-01

    μIn neurons of patients with Alzheimers's disease (AD) signs of cell cycle re-entry as well as polyploidy have been reported1, 2, indicating that the entire or a part of the genome of the neurons is duplicated before its death but mitosis is not initiated so that the cellular DNA content remains tetraploid. It was concluded, that this imbalance is the direct cause of the neuronal loss in AD3. Manual counting of polyploidal cells is possible but time consuming and possibly statistically insufficient. The aim of this study was to develop an automated method that detects the neuronal DNA content abnormalities with Laser Scanning Cytometry (LSC).Frozen sections of formalin-fixed brain tissue of AD patients and control subjects were labelled with anti-cyclin B and anti-NeuN antibodies. Immunolabelling was performed using Cy5- and Cy2-conjugated secondary antibodies and biotin streptavidin or tyramid signal amplification. In the end sections of 20m thickness were incubated with propidium iodide (PI) (50μg/ml) and covered on slides. For analysis by the LSC PI was used as trigger. Cells identified as neurons by NeuN expression were analyzed for cyclin B expression. Per specimen data of at least 10,000 neurons were acquired. In the frozen brain sections an automated quantification of the amount of nuclear DNA is possible with LSC. The DNA ploidy as well as the cell cycle distribution can be analyzed. A high number of neurons can be scanned and the duration of measuring is shorter than a manual examination. The amount of DNA is sufficiently represented by the PI fluorescence to be able to distinguish between eu- and polyploid neurons.

  12. Serial cranial computed-tomography scans in children with leukemia given two different forms of central nervous system therapy

    SciTech Connect

    Ochs, J.J.; Parvey, L.S.; Whitaker, J.N.; Bowman, W.P.; Ch'ien, L.; Campbell, M.; Coburn, T.

    1983-12-01

    Cranial computed tomography (CT) was used to estimate the frequency and permanence of brain abnormalities in 108 consecutive children with acute lymphoblastic leukemia (ALL). Fifty-five patients received cranial irradiation (1,800 rad) with intrathecal methotrexate (RT group) and 53 patients received intravenous and intrathecal methotrexate without irradiation (IVIT group). Continuation treatment included sequential drug pairs for the RT group and periodic IVIT methotrexate for the other group. After 12 to 24 months of serial evaluation, five (9%) of the 55 patients in the RT group have had CT scan abnormalities, compared to 10 (19%) of 52 in the IVIT group (p . 0.171). Fourteen of the 15 patients with CT scan abnormalities had focal or diffuse white-matter hypodensity; these have reverted to normal in most cases, reflecting a dynamic process. While such CT findings are of concern and may be an early indicator of central nervous system toxicity, this remains to be proven. Therapy should not be altered on the basis of abnormal CT scans alone but in the context of the entire clinical situation.

  13. Potential effect of CAD systems on the detection of actionable nodules in chest CT scans during routine reporting

    NASA Astrophysics Data System (ADS)

    Wormanns, Dag; Beyer, Florian; Butzbach, Arnauld; Zierott, Livia; Heindel, Walter

    2006-03-01

    The purpose of the presented study was to determine the impact of two different CAD systems used as concur-rent reader for detection of actionable nodules (>4 mm) on the interpretation of chest CT scans during routine reporting. Fifty consecutive MDCT scans (1 mm or 1.25 mm slice thickness, 0.8 mm reconstruction increment) were se-lected from clinical routine. All cases were read by a resident and a staff radiologist, and a written report was available in the radiology information system (RIS). The RIS report mentioned at least one actionable pulmonary nodule in 18 cases (50%) and did not report any pulmonary nodule in the remaining 32 cases. Two different recent CAD systems were independently applied to the 50 CT scans as concurrent reader with two radiologists: Siemens LungCare NEV and MEDIAN CAD-Lung. Two radiologists independently reviewed the CAD results and determined if a CAD result was a true positive or a false positive finding. Patients were classified into two groups: in group A if at least one actionable nodule was detected and in group B if no actionable nodules were found. The effect of CAD on routine reporting was simulated as set union of the findings of routine reporting and CAD thus applying CAD as concurrent reader. According to the RIS report group A (patients with at least one actionable nodule) contained 18 cases (36% of all 50 cases), and group B contained 32 cases. Application of a CAD system as concurrent reader resulted in detec-tion of additional CT scans with actionable nodules and reclassification into group A in 16 resp. 18 cases (radi-ologist 1 resp. radiologist 2) with Siemens NEV and in 19 resp. 18 cases with MEDIAN CAD-Lung. In seven cases MEDIAN CAD-Lung and in four cases Siemens NEV reclassified a case into group A while the other CAD system missed the relevant finding. Sensitivity on a nodule (>4 mm) base was .45 for Siemens NEV and .55 for MEDIAN CAD-Lung; the difference was not yet significant (p=.077). In our study use of CAD

  14. Micrometric precision of prosthetic dental crowns obtained by optical scanning and computer-aided designing/computer-aided manufacturing system.

    PubMed

    das Neves, Flávio Domingues; de Almeida Prado Naves Carneiro, Thiago; do Prado, Célio Jesus; Prudente, Marcel Santana; Zancopé, Karla; Davi, Letícia Resende; Mendonça, Gustavo; Soares, Carlos José

    2014-08-01

    The current study evaluated prosthetic dental crowns obtained by optical scanning and a computer-aided designing/computer-aided manufacturing system using micro-computed tomography to compare the marginal fit. The virtual models were obtained with four different scanning surfaces: typodont (T), regular impressions (RI), master casts (MC), and powdered master casts (PMC). Five virtual models were obtained for each group. For each model, a crown was designed on the software and milled from feldspathic ceramic blocks. Micro-CT images were obtained for marginal gap measurements and the data were statistically analyzed by one-way analysis of variance followed by Tukey's test. The mean vertical misfit was T = 62.6 ± 65.2 μm ; MC = 60.4 ± 38.4 μm; PMC = 58.1 ± 38.0 μm, and RI = 89.8 ± 62.8 μm. Considering a percentage of vertical marginal gap of up to 75 μm, the results were T = 71.5%, RI = 49.2%, MC = 69.6%, and PMC = 71.2%. The percentages of horizontal overextension were T = 8.5%, RI = 0%, MC = 0.8%, and PMC = 3.8%. Based on the results, virtual model acquisition by scanning the typodont (simulated mouth) or MC, with or without powder, showed acceptable values for the marginal gap. The higher result of marginal gap of the RI group suggests that it is preferable to scan this directly from the mouth or from MC.

  15. Micrometric precision of prosthetic dental crowns obtained by optical scanning and computer-aided designing/computer-aided manufacturing system

    NASA Astrophysics Data System (ADS)

    das Neves, Flávio Domingues; de Almeida Prado Naves Carneiro, Thiago; do Prado, Célio Jesus; Prudente, Marcel Santana; Zancopé, Karla; Davi, Letícia Resende; Mendonça, Gustavo; Soares, Carlos José

    2014-08-01

    The current study evaluated prosthetic dental crowns obtained by optical scanning and a computer-aided designing/computer-aided manufacturing system using micro-computed tomography to compare the marginal fit. The virtual models were obtained with four different scanning surfaces: typodont (T), regular impressions (RI), master casts (MC), and powdered master casts (PMC). Five virtual models were obtained for each group. For each model, a crown was designed on the software and milled from feldspathic ceramic blocks. Micro-CT images were obtained for marginal gap measurements and the data were statistically analyzed by one-way analysis of variance followed by Tukey's test. The mean vertical misfit was T=62.6±65.2 μm; MC=60.4±38.4 μm; PMC=58.1±38.0 μm, and RI=89.8±62.8 μm. Considering a percentage of vertical marginal gap of up to 75 μm, the results were T=71.5%, RI=49.2%, MC=69.6%, and PMC=71.2%. The percentages of horizontal overextension were T=8.5%, RI=0%, MC=0.8%, and PMC=3.8%. Based on the results, virtual model acquisition by scanning the typodont (simulated mouth) or MC, with or without powder, showed acceptable values for the marginal gap. The higher result of marginal gap of the RI group suggests that it is preferable to scan this directly from the mouth or from MC.

  16. Development of a Laser Line Scan LIDAR Imaging System for AUV Use

    DTIC Science & Technology

    2011-09-30

    October 1, 20010 – August 31, 2011. During this period, the project has progressed as we (Lockheed Martin Aculight, LMA , and SIO) have designed...built, and tested the hardware optical and electronic components for the final system. System tests by LMA have confirmed that the performance of the...final configuration optical components will meet system specification goals. SIO supervised the assembly and delivery to LMA of the system chassis

  17. First results from a combination side-scan sonar and seafloor mapping system (SeaMARC II)

    SciTech Connect

    Blackinton, J.G.; Hussong, D.M.; Kosalos, J.G.

    1983-05-01

    SeaMARC II (Sea Mapping and Remote Characterization) is both a conventional side-scan sonar and a bathymetric mapping system. It is a 12kHz, long-range, shallow-towed, high-speed system that produces an ocean floor image up to 10km wide. (By contrast SeaMARC I is a 30kHz deep towed, slow-speed side-scan only system.) Bathymetry is determined by measuring 4000 times each second the magnitude and arrival angle of narrow band acoustic energy returned from each side of ship's track. Off-line processing of this series of vectors produces a seafloor bathymetric map along the track with a width 3.4 times the water depth. A 10 knot tow capability allows more than 4000 square kilometers to be surveyed each day. In practice, the average returns from a relatively flat part of the survey area are used to generate a function relating acoustic arrival angle to measured electrical angle. This procedure corrects for local sound speed structure. With this function, the measurements from returns with adequately large magnitudes are converted to acoustic arrival angle. These angles are corrected for tow body attitude and, with the arrival times (range), are converted to horizontal (X) and vertical (Z) distances from the tow body to the reflector. Side-scan images are a combination of the small scale reflecting properties of the bottom (micro-reflectivity) and the specular reflections from bathymetric slopes (macro-reflectivity). SeaMarc II has the unique ability to acquire synoptic data that will allow the two effects to be separated. This unique combination also allows more accurate and rapid understanding of bottom character than with either output by itself.

  18. Maximum likelihood estimate of target angles for a conical scan tracking system in the presence of speckle.

    PubMed

    Lubnau, D G

    1977-01-01

    The equation for the maximum likelihood estimate of target angle is derived for a conical scan tracking system when the target produces speckle and Gaussian noise is present. Operation with a direct detection receiver is assumed with the average photon flux large enough so that the discrete nature of photoelectric events may be ignored. For large average SNRs, the estimate is shown to be unbiased and the variance of the estimate limited by both the average SNR and the number of degrees of freedom of the detected field.

  19. Mobile Laser Scanning Systems for Measuring the Clearance Gauge of Railways: State of Play, Testing and Outlook

    PubMed Central

    Mikrut, Sławomir; Kohut, Piotr; Pyka, Krystian; Tokarczyk, Regina; Barszcz, Tomasz; Uhl, Tadeusz

    2016-01-01

    The paper contains a survey of mobile scanning systems for measuring the railway clearance gauge. The research was completed as part of the project carried out for the PKP (PKP Polish Railway Lines S.A., Warsaw, Poland) in 2011–2013. The authors conducted experiments, including a search for the latest solutions relating to mobile measurement systems that meet the basic requirement. At the very least, these solutions needed to be accurate and have the ability for quick retrieval of data. In the paper, specifications and the characteristics of the component devices of the scanning systems are described. Based on experiments, the authors did some examination of the selected mobile systems to be applied for measuring the clearance gauge. The Riegl (VMX-250) and Z+F (Zoller + Fröhlich) Solution were tested. Additional test measurements were carried out within a 30-kilometer section of the Warsaw-Kraków route. These measurements were designed so as to provide various elements of the railway infrastructure, the track geometry and the installed geodetic control network. This ultimately made it possible to reduce the time for the preparation of geodetic reference measurements for the testing of the accuracy of the selected systems. Reference measurements included the use of the polar method to select profiles perpendicular to the axis of the track. In addition, the coordinates selected were well defined as measuring points of the objects of the infrastructure of the clearance gauge. All of the tested systems meet the accuracy requirements initially established (within the range of 2 cm as required by the PKP). The tested systems have shown their advantages and disadvantages. PMID:27187400

  20. Gallium scan

    MedlinePlus

    ... material called gallium and is a type of nuclear medicine exam. A related test is gallium scan ... Brown ML, Forstrom LA, et al. Society of nuclear medicine procedure guideline for gallium scintigraphy in inflammation. ...

  1. CT Scan

    MedlinePlus

    ... exposing your baby to radiation. Reactions to contrast material In certain cases, your doctor may recommend you ... for a few hours before your scan Contrast material A special dye called a contrast material is ...

  2. Expected Characteristics of Global Wind Profile Measurements with a Scanning, Hybrid, Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.

    2008-01-01

    Over 20 years of investigation by NASA and NOAA scientists and Doppler lidar technologists into a global wind profiling mission from earth orbit have led to the current favored concept of an instrument with both coherent- and direct-detection pulsed Doppler lidars (i.e., a hybrid Doppler lidar) and a stepstare beam scanning approach covering several azimuth angles with a fixed nadir angle. The nominal lidar wavelengths are 2 microns for coherent detection, and 0.355 microns for direct detection. The two agencies have also generated two sets of sophisticated wind measurement requirements for a space mission: science demonstration requirements and operational requirements. The requirements contain the necessary details to permit mission design and optimization by lidar technologists. Simulations have been developed that connect the science requirements to the wind measurement requirements, and that connect the wind measurement requirements to the Doppler lidar parameters. The simulations also permit trade studies within the multi-parameter space. These tools, combined with knowledge of the state of the Doppler lidar technology, have been used to conduct space instrument and mission design activities to validate the feasibility of the chosen mission and lidar parameters. Recently, the NRC Earth Science Decadal Survey recommended the wind mission to NASA as one of 15 recommended missions. A full description of the wind measurement product from these notional missions and the possible trades available are presented in this paper.

  3. Co-Registration of DSMs Generated by Uav and Terrestrial Laser Scanning Systems

    NASA Astrophysics Data System (ADS)

    Ancil Persad, Ravi; Armenakis, Costas

    2016-06-01

    An approach for the co-registration of Digital Surface Models (DSMs) derived from Unmanned Aerial Vehicles (UAVs) and Terrestrial Laser Scanners (TLS) is proposed. Specifically, a wavelet-based feature descriptor for matching surface keypoints on the 2.5D DSMs is developed. DSMs are useful in wide-scope of various applications such as 3D building modelling and reconstruction, cultural heritage, urban and environmental planning, aircraft navigation/path routing, accident and crime scene reconstruction, mining as well as, topographic map revision and change detection. For these listed applications, it is not uncommon that there will be a need for automatically aligning multi-temporal DSMs which may have been acquired from multiple sensors, with different specifications over a period of time, and may have various overlaps. Terrestrial laser scanners usually capture urban facades in an accurate manner; however this is not the case for building roof structures. On the other hand, vertical photography from UAVs can capture the roofs. Therefore, the automatic fusion of UAV and laser-scanning based DSMs is addressed here as it serves various geospatial applications.

  4. Modeling of Electronic Transport in Scanning Tunneling Microscope Tip-Carbon Nanotube Systems

    NASA Technical Reports Server (NTRS)

    Yamada, Toshishige; Kwak, Dochan (Technical Monitor)

    2000-01-01

    A model is proposed for two observed current-voltage (I-V) patterns in a recent experiment with a scanning tunneling microscope tip and a carbon nanotube. We claim that there are two mechanical contact modes for a tip (metal) -nanotube (semiconductor) junction (1) with or (2) without a tiny vacuum gap (0.1 - 0.2 nm). With the tip grounded, the tunneling case in (1) would produce large dI/dV with V > 0, small dI/dV with V < 0, and I = 0 near V = 0 for an either n- or p-nanotube; the Schottky mechanism in (2) would result in I does not equal 0 only with V < 0 for an n-nanotube, and the bias polarities would be reversed for a p-nanotube. The two observed I-V patterns are thus entirely explained by a tip-nanotube contact of the two types, where the nanotube must be n-type.

  5. System for formation of magnetic field to scan a charged particle beam along an arbitrary trajectory on a target

    NASA Astrophysics Data System (ADS)

    Kazarinov, N. Yu.; Kazacha, V. I.; Lebedev, N. I.; Fateev, A. A.

    2015-11-01

    A new scanning system is considered. The system is developed at JINR and has a number of characteristic features. The windings of the bending magnets with a large number of ampere-turns operate at relatively low frequencies (≤20 Hz) to maintain the reactive power within reasonable limits. The winding power supplies use feedback systems to shape currents of the given waveform and amplitude. The main structural features and parameters of the prototype magnet and the results of developing and testing the electronic circuit for supplying the magnet with a current of the given waveform are presented. Density distributions of various ions on the target are calculated for one of the U400-M cyclotron beam lines using the parameters of the new scanners.

  6. High-angle annular dark field scanning transmission electron microscopy on carbon-based functional polymer systems.

    PubMed

    Sourty, Erwan; van Bavel, Svetlana; Lu, Kangbo; Guerra, Ralph; Bar, Georg; Loos, Joachim

    2009-06-01

    Two purely carbon-based functional polymer systems were investigated by bright-field conventional transmission electron microscopy (CTEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). For a carbon black (CB) filled polymer system, HAADF-STEM provides high contrast between the CB agglomerates and the polymer matrix so that details of the interface organization easily can be revealed and assignment of the CB phase is straightforward. For a second system, the functional polymer blend representing the photoactive layer of a polymer solar cell, details of its nanoscale organization could be observed that were not accessible with CTEM. By varying the camera length in HAADF-STEM imaging, the contrast can be enhanced between crystalline and amorphous compounds due to diffraction contrast so that nanoscale interconnections between domains are identified. In general, due to its incoherent imaging characteristics HAADF-STEM allows for reliable interpretation of the data obtained.

  7. The evaluation of unmanned aerial system-based photogrammetry and terrestrial laser scanning to generate DEMs of agricultural watersheds

    NASA Astrophysics Data System (ADS)

    Ouédraogo, Mohamar Moussa; Degré, Aurore; Debouche, Charles; Lisein, Jonathan

    2014-06-01

    Agricultural watersheds tend to be places of intensive farming activities that permanently modify their microtopography. The surface characteristics of the soil vary depending on the crops that are cultivated in these areas. Agricultural soil microtopography plays an important role in the quantification of runoff and sediment transport because the presence of crops, crop residues, furrows and ridges may impact the direction of water flow. To better assess such phenomena, 3-D reconstructions of high-resolution agricultural watershed topography are essential. Fine-resolution topographic data collection technologies can be used to discern highly detailed elevation variability in these areas. Knowledge of the strengths and weaknesses of existing technologies used for data collection on agricultural watersheds may be helpful in choosing an appropriate technology. This study assesses the suitability of terrestrial laser scanning (TLS) and unmanned aerial system (UAS) photogrammetry for collecting the fine-resolution topographic data required to generate accurate, high-resolution digital elevation models (DEMs) in a small watershed area (12 ha). Because of farming activity, 14 TLS scans (≈ 25 points m- 2) were collected without using high-definition surveying (HDS) targets, which are generally used to mesh adjacent scans. To evaluate the accuracy of the DEMs created from the TLS scan data, 1098 ground control points (GCPs) were surveyed using a real time kinematic global positioning system (RTK-GPS). Linear regressions were then applied to each DEM to remove vertical errors from the TLS point elevations, errors caused by the non-perpendicularity of the scanner's vertical axis to the local horizontal plane, and errors correlated with the distance to the scanner's position. The scans were then meshed to generate a DEMTLS with a 1 × 1 m spatial resolution. The Agisoft PhotoScan and MicMac software packages were used to process the aerial photographs and generate a DEMPSC

  8. NAVIS-An UGV Indoor Positioning System Using Laser Scan Matching for Large-Area Real-Time Applications

    PubMed Central

    Tang, Jian.; Chen, Yuwei.; Jaakkola, Anttoni.; Liu, Jinbing.; Hyyppä, Juha.; Hyyppä, Hannu.

    2014-01-01

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  9. NAVIS-An UGV indoor positioning system using laser scan matching for large-area real-time applications.

    PubMed

    Tang, Jian; Chen, Yuwei; Jaakkola, Anttoni; Liu, Jinbing; Hyyppä, Juha; Hyyppä, Hannu

    2014-07-04

    Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz

  10. 77 FR 59941 - Prospective Grant of Exclusive License: Terahertz Scanning Systems for Cancer Pathology

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... Systems for Cancer Pathology AGENCY: National Institutes of Health, Public Health Service, HHS. ACTION... systems for cancer pathology. Upon the expiration or termination of the exclusive evaluation option... therefore potentially suitable for medical applications such as cancer diagnosis of living subjects...

  11. System and Campus Level Enrollment Projections and Environmental Scan, 1988-1998.

    ERIC Educational Resources Information Center

    Gaylord, Thomas A.; And Others

    Alaska's first long-range, system-wide enrollment projection study since the inception of the higher education system's restructuring plan is reported. The study was undertaken in response to statewide economic distress, a decline in state funding of higher education, and a pattern of out-migration by the college-age population, particularly in…

  12. Real-time B-scan ultrasonic imaging using a digital phased array system for NDE

    NASA Astrophysics Data System (ADS)

    Dunki-Jacobs, Robert; Thomas, Lewis

    A demonstration is presented of the ability to produce real-time images of metals on the basis of a phased-array ultrasound system. Attention is given to the critical role played by a beam-former. It is established that the present imaging system's resolution approaches the theoretical capabilities of the given aperture size and wavelength.

  13. Environmental Scanning in Educational Planning: Establishing a Strategic Trend Information System.

    ERIC Educational Resources Information Center

    Morrison, James L.

    The systematic evaluation of the macroenvironment is sometimes referred to as a strategic trend information system. Strategic trend intelligence systems are highly developed, systematic intelligence programs that focus on trends and events in the external environment and provide institutions with knowledge to reduce areas of uncertainty and with…

  14. Scanning system for determination of optical defects. Quarterly report, October--December 1971

    SciTech Connect

    Saunders, P.K.

    1997-09-01

    A method for determining percent of light transmission through a machined lucite lens and a first surface mirror is described. A laser, photodiode detector and two positioning fixtures comprise a system for testing mirrors and machined lenses for optical defects.

  15. Laser-ranging scanning system to observe topographical deformations of volcanoes.

    PubMed

    Aoki, T; Takabe, M; Mizutani, K; Itabe, T

    1997-02-20

    We have developed a laser-ranging system to observe the topographical structure of volcanoes. This system can be used to measure the distance to a target by a laser and shows the three-dimensional topographical structure of a volcano with an accuracy of 30 cm. This accuracy is greater than that of a typical laser-ranging system that uses a corner-cube reflector as a target because the reflected light jitters as a result of inclination and unevenness of the target ground surface. However, this laser-ranging system is useful for detecting deformations of topographical features in which placement of a reflector is difficult, such as in volcanic regions.

  16. Computer-aided detection system for lung cancer in computed tomography scans: Review and future prospects

    PubMed Central

    2014-01-01

    Introduction The goal of this paper is to present a critical review of major Computer-Aided Detection systems (CADe) for lung cancer in order to identify challenges for future research. CADe systems must meet the following requirements: improve the performance of radiologists providing high sensitivity in the diagnosis, a low number of false positives (FP), have high processing speed, present high level of automation, low cost (of implementation, training, support and maintenance), the ability to detect different types and shapes of nodules, and software security assurance. Methods The relevant literature related to “CADe for lung cancer” was obtained from PubMed, IEEEXplore and Science Direct database. Articles published from 2009 to 2013, and some articles previously published, were used. A systemic analysis was made on these articles and the results were summarized. Discussion Based on literature search, it was observed that many if not all systems described in this survey have the potential to be important in clinical practice. However, no significant improvement was observed in sensitivity, number of false positives, level of automation and ability to detect different types and shapes of nodules in the studied period. Challenges were presented for future research. Conclusions Further research is needed to improve existing systems and propose new solutions. For this, we believe that collaborative efforts through the creation of open source software communities are necessary to develop a CADe system with all the requirements mentioned and with a short development cycle. In addition, future CADe systems should improve the level of automation, through integration with picture archiving and communication systems (PACS) and the electronic record of the patient, decrease the number of false positives, measure the evolution of tumors, evaluate the evolution of the oncological treatment, and its possible prognosis. PMID:24713067

  17. Miniaturized, multibeam, solid state scanning laser radar in automobile collision avoidance sensor systems

    NASA Astrophysics Data System (ADS)

    Sargent, Ronald A.

    1995-06-01

    Recent intelligent transportation systems (ITS) initiatives sponsored by commercial transportation companies and the U.S. Department of Transportation include an area dedicated to Automated Vehicle Control Systems (AVCS). AVCS systems are dedicated to improving passenger automobile safety, efficiency, and impact on the environment. Minimizing the number of automobile collisions through automated obstacle detection and vehicle response is vital to this effort. Simple, reliable, low cost sensors installed in automobiles to provide driver warning and/or input to vehicle systems such as braking or cruise control are the key piece to making this technology as common as air bags and seat belts. EPA emission regulations now require specific areas to periodically report the mix of vehicle types. These reports must include in the mix the 13 possible categories for vehicles. Simple low cost senors installed as part of the traffic management system will facilitate the determination of vehicle category. Laser Atlanta has recently developed two distinct types of sensors that utilize a unique multi- beam approach to detect `targets' that are potential hazards. They also provide range and range rate data to automobile control and traffic management systems.

  18. Poultry carcass inspection by a fast line-scan imaging system: results from in-plant testing

    NASA Astrophysics Data System (ADS)

    Chao, Kuanglin; Yang, Chun-Chieh; Chen, Yud-Ren; Chan, Diane E.; Kim, Moon S.

    2006-10-01

    During in-plant testing of a hyperspectral line-scan imaging system, images were acquired of wholesome and systemically diseased chickens on a commercial processing line moving at a speed 70 birds per minute. A fuzzy logic based algorithm using four key wavelengths, 468 nm, 501 nm, 582 nm, 629 nm, was developed using image data from the validation set of images of 543 wholesome and 66 systemically diseased chickens. A classification method using the fuzzy logic based algorithm was then tested on the testing set of images of 457 wholesome and 37 systemically diseased chickens, as well as 80 systemically diseased chickens that were imaged off-shift during breaks between normal processing shifts of the chicken plant. The classification method correctly identified 89.7% of wholesome chicken images and 98.5% of systemically diseased chicken images in the validation set. For the testing data set, the method correctly classified 96.7 % of 457 wholesome chicken images and 100% of 37 systemically diseased chicken images. The 80 images acquired off-shift were also 100% correctly identified.

  19. Fiber-Scanned Microdisplays

    NASA Technical Reports Server (NTRS)

    Crossman-Bosworth, Janet; Seibel, Eric

    2010-01-01

    Helmet- and head-mounted display systems, denoted fiber-scanned microdisplays, have been proposed to provide information in an "augmented reality" format (meaning that the information would be optically overlaid on the user's field of view).

  20. Multiple Reflector Scanning Antennas

    NASA Astrophysics Data System (ADS)

    Shen, Bing

    Narrow beamwidth antenna systems are important to remote sensing applications and point-to-point communication systems. In many applications the main beam of the antenna radiation pattern must be scannable over a region of space. Scanning by mechanically skewing the entire antenna assembly is difficult and in many situations is unacceptable. Performance during scan is, of course, also very important. Traditional reflector systems employing the well-focused paraboloidal -shaped main reflector accomplish scan by motion of a few feeds, or by phase steering a focal plane feed array. Such scanning systems can experience significant gain loss. Traditional reflecting systems with a spherical main reflector have low aperture efficiency and poor side lobe and cross polarization performance. This dissertation introduces a new approach to the design of scanning spherical reflector systems, in which the performance weaknesses of high cross polarization and high side lobe levels are avoided. Moreover, the low aperture utilization common in spherical reflectors is overcome. As an improvement to this new spherical main reflector configuration, a flat mirror reflector is introduced to minimize the mechanical difficulties to scan the main beam. In addition to the reflector system design, reflector antenna performance evaluation is also important. The temperature resolution issue important for earth observation radiometer antennas is studied, and a new method to evaluate and optimize such temperature resolution is introduced.

  1. Laser beam scanning system for irradiation in an external quadrangular form for soldering of quad flat package IC

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Hitoshi; Homma, Tetsuya

    2015-02-01

    We propose a new soldering process and a system for a quad flat package IC (QFP-IC). The incident line-formed laser beam converted by this system can realize an external quadrangular form line for the non-contact regional heating, to provide thin and light weight electronic packages as required. The laser beam pumped by an yttrium aluminum garnet (YAG) laser oscillator is split into four beams. Using a galvano motor, which can scan the reflection mirror with high frequencies, the laser beam can change the heating line. The soldering time for QFP-IC of 100 pins with the 0.65 mm pitch was 6 s. As the regional heating just only junctions, the temperature in the resin package was lower than 141 °C after solder fusion. From the experimental result, it is confirmed that this method is less damage to a resin package than a conventional whole heating method.

  2. Remote measurement utilizing NASA's scanning laser Doppler systems. Volume 1. Laser Doppler wake vortex tracking at Kennedy Airport

    NASA Technical Reports Server (NTRS)

    Krause, M. C.; Wilson, D. J.; Howle, R. E.; Edwards, B. B.; Craven, C. E.; Jetton, J. L.

    1976-01-01

    Test operations of the Scanning Laser Doppler System (SLDS) at Kennedy International Airport (KIA) during August 1974 through June 1975 are reported. A total of 1,619 data runs was recorded with a totally operational system during normal landing operations at KIA. In addition, 53 data runs were made during cooperative flybys with the C880 for a grand total of 1672 recorded vortex tracks. Test crews were in attendance at KIA for 31 weeks, of which 25 weeks were considered operational and the other six were packing, unpacking, setup and check out. Although average activity equates to 67 recorded landing operations per week, two periods of complete runway inactivity spanned 20 days and 13 days, respectively. The operation frequency therefore averaged about 88 operations per week.

  3. Polymorphic transition of solid-fats dispersed systems — its characterization by a novel method and scanning electron microscopy observation

    NASA Astrophysics Data System (ADS)

    Hirokawa, Norio; Ueda, Masahiro; Harano, Yoshio

    1994-08-01

    Solid-fats dispersed systems, such as margarine, butter and cacao-butter, were characterized by a novel method based on liquid permeation under pressure, for the simultaneous measurement of a solid-content ɛ p and an average diameter dp of solid particles (fats crystals) in them. Further, micro-structures of these systems were observed by a scanning electron microscope (SEM). As the result, it has been clarified that the spherical fats crystals of several μm in size appeared in the initial solid-fats products are agglomerates of fine particles of ca. 0.1 μm and that these fine particles are uniformly redispersed during an annealing treatment accompanying the reduction of ɛ p and dp. It is strongly suggested that this phenomenon is caused by a transition of fat crystals into a more stable polymorph.

  4. Multitip scanning gate microscopy for ballistic transport studies in systems with a two-dimensional electron gas

    NASA Astrophysics Data System (ADS)

    Kolasiński, K.; Szafran, B.; Hackens, B.

    2015-05-01

    We consider conductance mapping of systems based on the two-dimensional electron gas with scanning gate microscopy using two or more tips of an atomic force microscope. The paper contains the results of numerical simulations for a model tip potential. In addition, a few procedures are proposed for the extraction and manipulation of ballistic transport properties. In particular, we demonstrate that the multitip techniques can be used to obtain a readout of the Fermi wavelength, to detect potential defects, to filter specific transverse modes, and to tune the system into resonant conditions under which a stable map of the local density of states can be extracted from conductance maps using a third tip.

  5. A flexible implementation of scanning probe microscopy utilizing a multifunction system linked to a PC-Pentium controller

    NASA Astrophysics Data System (ADS)

    Barchesi, C.; Cricenti, A.; Generosi, R.; Giammichele, C.; Luce, M.; Rinaldi, M.

    1997-10-01

    A flexible electronic setup on a PC platform and the software implementation in Windows Microsoft environment, for a multipurpose head for scanning probe microscopy (SPM), has been developed. The integrated, multiapplication data acquisition system is linked to a PC-Pentium controller, through a digital I/O board, and consists of: (i) an asynchronous acquisition for real time removal of following error from SPM images; (ii) a three-axes, computer controlled micropositioning stage; (iii) software for electronic control, data acquisition, and graphics elaboration performed through subroutines of Visual Basic (Visual Basic Programming System Professional edition for Windows is a registered trademark of Microsoft Corporation, USA.), and PV-WAVE personal edition. (PV-WAVE Personal edition for Windows is a registered trademark of Visual Numerics, USA.)

  6. Digital mapping of side-scan sonar data with the Woods Hole Image Processing System software

    USGS Publications Warehouse

    Paskevich, Valerie F.

    1992-01-01

    Since 1985, the Branch of Atlantic Marine Geology has been involved in collecting, processing and digitally mosaicking high and low resolution sidescan sonar data. In the past, processing and digital mosaicking has been accomplished with a dedicated, shore-based computer system. Recent development of a UNIX-based image-processing software system includes a series of task specific programs for pre-processing sidescan sonar data. To extend the capabilities of the UNIX-based programs, development of digital mapping techniques have been developed. This report describes the initial development of an automated digital mapping procedure. Included is a description of the programs and steps required to complete the digital mosaicking on a UNIXbased computer system, and a comparison of techniques that the user may wish to select.

  7. Regional Variation in the Severity of Pesticide Exposure Outcomes: Applications of Geographic Information Systems and Spatial Scan Statistics

    PubMed Central

    Sudakin, Daniel L.

    2009-01-01

    Introduction In a previous study, Geographic Information Systems (GIS) and spatial scan statistics were utilized to assess regional clustering of symptomatic pesticide exposure incidents that were reported to a state Poison Control Center (PCC) during a single year. In the current study, we analyzed five subsequent years of PCC data to test whether there are significant geographic differences in pesticide exposure incidents resulting in serious (moderate, major, and fatal) medical outcomes. Methods A Poison Control Center provided data on unintentional pesticide exposure incidents for the time period 2001−2005. Data were abstracted to identify the geographic location of the caller, the location where the exposure occurred, the exposure route, and the medical outcome. Results The results yielded 273 incidents resulting in moderate (n=261), major effects (n=10), or fatalities (n=2). Analysis of these data using spatial scan statistics resulted in the identification of a geographic area consisting of 2 adjacent counties (one urban, one rural) where statistically significant clustering of serious outcomes was observed. The relative risk of moderate, major, and fatal outcomes was 2.0 in this spatial cluster (p=0.0005). Conclusions Poison Control Center data, GIS, and spatial scan statistics can be effectively utilized to identify clustering of serious incidents involving human exposure to pesticides. These analyses may be useful for public health officials to target preventive interventions. Further investigation is warranted to better understand the potential explanations for geographical clustering, and to assess whether preventive interventions have an impact on reducing pesticide exposure incidents resulting in serious medical outcomes. PMID:19306192

  8. Feasibility for detection of autofluorescent signatures in rat organs using a novel excitation-scanning hyperspectral imaging system

    NASA Astrophysics Data System (ADS)

    Favreau, Peter F.; Deal, Joshua A.; Weber, David S.; Rich, Thomas C.; Leavesley, Silas J.

    2016-04-01

    The natural fluorescence (autofluorescence) of tissues has been noted as a biomarker for cancer for several decades. Autofluorescence contrast between tumors and healthy tissues has been of significant interest in endoscopy, leading to development of autofluorescence endoscopes capable of visualizing 2-3 fluorescence emission wavelengths to achieve maximal contrast. However, tumor detection with autofluorescence endoscopes is hindered by low fluorescence signal and limited quantitative information, resulting in prolonged endoscopic procedures, prohibitive acquisition times, and reduced specificity of detection. Our lab has designed a novel excitation-scanning hyperspectral imaging system with high fluorescence signal detection, low acquisition time, and enhanced spectral discrimination. In this study, we surveyed a comprehensive set of excised tissues to assess the feasibility of detecting tissue-specific pathologies using excitation-scanning. Fresh, untreated tissue specimens were imaged from 360 to 550 nm on an inverted fluorescence microscope equipped with a set of thin-film tunable filters (Semrock, A Unit of IDEX). Images were subdivided into training and test sets. Automated endmember extraction (ENVI 5.1, Exelis) with PCA identified endmembers within training images of autofluorescence. A spectral library was created from 9 endmembers. The library was used for identification of endmembers in test images. Our results suggest (1) spectral differentiation of multiple tissue types is possible using excitation scanning; (2) shared spectra between tissue types; and (3) the ability to identify unique morphological features in disparate tissues from shared autofluorescent components. Future work will focus on isolating specific molecular signatures present in tissue spectra, and elucidating the contribution of these signatures in pathologies.

  9. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    SciTech Connect

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  10. Understanding Ionic Bonding--A Scan across the Croatian Education System

    ERIC Educational Resources Information Center

    Vladušic, R.; Bucat, R. B.; Ožic, M.

    2016-01-01

    A study was conducted on the understandings of the accepted model of ionic substances that are held by participants at all levels of the chemical education system in Croatia, including secondary school students, university students, and chemistry teachers. We follow the research of Taber who found that a diagram of a layer of a sodium chloride…

  11. Exploration of two-enzyme coupled catalysis system using scanning electrochemical microscopy.

    PubMed

    Wu, Zeng-Qiang; Jia, Wen-Zhi; Wang, Kang; Xu, Jing-Juan; Chen, Hong-Yuan; Xia, Xing-Hua

    2012-12-18

    In biological metabolism, a given metabolic process usually occurs via a group of enzymes working together in sequential pathways. To explore the metabolism mechanism requires the understanding of the multienzyme coupled catalysis systems. In this paper, an approach has been proposed to study the kinetics of a two-enzyme coupled reaction using SECM combining numerical simulations. Acetylcholine esterase and choline oxidase are immobilized on cysteamine self-assembled monolayers on tip and substrate gold electrodes of SECM via electrostatic interactions, respectively. The reaction kinetics of this two-enzyme coupled system upon various separation distance precisely regulated by SECM are measured. An overall apparent Michaelis-Menten constant of this enzyme cascade is thus measured as 2.97 mM at an optimal tip-substrate gap distance of 18 μm. Then, a kinetic model of this enzyme cascade is established for evaluating the kinetic parameters of individual enzyme by using the finite element method. The simulated results demonstrate the choline oxidase catalytic reaction is the rate determining step of this enzyme cascade. The Michaelis-Menten constant of acetylcholine esterase is evaluated as 1.8 mM. This study offers a promising approach to exploring mechanism of other two-enzyme coupled reactions in biological system and would promote the development of biosensors and enzyme-based logic systems.

  12. Feasibility test of a solid state spin-scan photo-imaging system

    NASA Technical Reports Server (NTRS)

    Laverty, N. P.

    1973-01-01

    The feasibility of using a solid-state photo-imaging system to obtain resolution imagery from a Pioneer-type spinning spacecraft in future exploratory missions to the outer planets is discussed. Evaluation of the photo-imaging system performance, based on electrical video signal analysis recorded on magnetic tape, shows that the signal-to-noise (S/N) ratios obtained at low spatial frequencies exceed the anticipated performance and that measured modulation transfer functions exhibited some degradation in comparison with the estimated values, primarily owing to the difficulty in obtaining a precise focus of the optical system in the laboratory with the test patterns in close proximity to the objective lens. A preliminary flight model design of the photo-imaging system is developed based on the use of currently available phototransistor arrays. Image quality estimates that will be obtained are presented in terms of S/N ratios and spatial resolution for the various planets and satellites. Parametric design tradeoffs are also defined.

  13. Pulse compression techniques to improve modulated pulsed laser line scan systems

    NASA Astrophysics Data System (ADS)

    Lee, Robert W.; Nash, Justin K.; Cochenour, Brandon M.; Mullen, Linda J.

    2015-05-01

    A modulated pulse laser imaging system has been developed which utilizes coded/chirped RF modulation to mitigate the adverse effects of optical scattering in degraded visual underwater environments. Current laser imaging techniques employ either short pulses or single frequency modulated pulses to obtain both intensity and range images. Systems using short pulses have high range resolution but are susceptible to scattering due to the wide bandwidth nature of the pulse. Range gating can be used to limit the effects of backscatter, but this can lead to blind spots in the range image. Modulated pulse systems can help suppress the contribution from scattered light in generated imagery without gating the receiver. However, the use of narrowband, single tone modulation results in limited range resolution where small targets are camouflaged within the background. This drives the need for systems which have high range resolution while still suppressing the effects of scattering caused by the environment. Coded/chirped modulated pulses enable the use of radar pulse compression techniques to substantially increase range resolution while also providing a way to discriminate the object of interest from the light scattered from the environment. Linearly frequency chirped waveforms and phase shift keyed barker codes were experimentally investigated to determine the effects that pulse compression would have on intensity/range data. The effect of modulation frequency on the data produced with both wideband and narrowband modulation was also investigated. The results from laboratory experiments will be presented and compared to model predictions.

  14. SCANS (Shipping Cask ANalysis System) a microcomputer based analysis system for shipping cask design review: Volume 4--Theory manual: Thermal analysis

    SciTech Connect

    Johnson, G.L.; Shapiro, A.B.

    1989-02-01

    TOPAZ is the two-dimensional, implicit, finite-element computer code included in the SCANS cask analysis system for heat conduction calculations. TOPAZ, a code developed on LLNL mainframes, has been implemented on IBM PC computers. This report provides documentation of TOPAZ controls and variables and a description of the numerical algorithms used. Sample problems with analytical solutions are presented. 10 refs., 32 figs., 11 tabs.

  15. A Portable Airborne Scanning Lidar System for Ocean and Coastal Applications

    DTIC Science & Technology

    2009-06-26

    has been quantified in many studies with several different airborne lidar systems. Robertson et al. (2007) measured beach erosion caused by Hurricane...Mech., 156, 505–531. Robertson , W., K. Zhang, and D. Whitman, 2007: Hurricane- induced beach change derived from airborne laser mea- surements near...level changes on Southern California beaches. Ph.D. thesis, University of California, San Diego, 155 pp. ——, R. Guza, R. Gutierrez, and R. Seymour

  16. High Precision Magnetic Field Scanning System for the New Muon g-2 Experiment

    NASA Astrophysics Data System (ADS)

    Hong, Ran; Muon g-2 collaboration Collaboration

    2017-01-01

    The New Muon g-2 Experiment (E989) at Fermilab will measure the anomalous magnetic moment of muon aμ aiming at a precision of 140 ppb. This new experiment will shed light on the long-standing 3.5 standard deviation between the previous muon g-2 measurement (E821) at Brookhaven National Laboratory and the Standard Model calculation, and potentially discover new physics. The New Muon g-2 Experiment measures the precession frequency of muon in a uniform magnetic field, and the magnetic field experienced by the muons needs to be measured with a precision better than 70 ppb. For the measurement of the magnetic field in the muon storage region, the former trolley system from E821 with 17 NMR probes was refurbished and upgraded with new electronics, probes and a modern motion control system. A test solenoid magnet was set up at Argonne National Laboratory for calibrating the NMR probes and the precision studies of systematic uncertainties. In this presentation, we will describe the trolley motion control scheme, the trolley position measurement methods, the electronic system for activating and reading the NMR probes and the test solenoid facility.

  17. Bone scanning in otolaryngology.

    PubMed

    Noyek, A M

    1979-09-01

    Modern radionuclide bone scanning has introduced a new concept in physiologic and anatomic diagnostic imaging to general medicine. As otolaryngologists must diagnose and treat disease in relation to the bony and/or cartilaginous supporting structures of the neurocranium and upper airway, this modality should be included in the otolaryngologist's diagnostic armamentarium. It is the purpose of this manuscript to study the specific applications of bone scanning to our specialty at this time, based on clinical experience over the past three years. This thesis describes the development of bone scanning in general (history of nuclear medicine and nuclear physics; history of bone scanning in particular). General concepts in nuclear medicine are then presented; these include a discussion of nuclear semantics, principles of radioactive emmissions, the properties 99mTc as a radionuclide, and the tracer principle. On the basis of these general concepts, specific concepts in bone scanning are then brought forth. The physiology of bone and the action of the bone scan agents is presented. Further discussion considers the availability and production of the bone scan agent, patient factors, the gamma camera, the triphasic bone scan and the ultimate diagnostic principle of the bone scan. Clinical applications of bone scanning in otolaryngology are then presented in three sections. Proven areas of application include the evaluation of malignant tumors of the head and neck, the diagnosis of temporomandibular joint disorders, the diagnosis of facial fractures, the evaluation of osteomyelitis, nuclear medicine imaging of the larynx, and the assessment of systemic disease. Areas of adjunctive or supplementary value are also noted, such as diagnostic imaging of meningioma. Finally, areas of marginal value in the application of bone scanning are described.

  18. A Novel Concept for Observing Land-Surface-Atmosphere Feedback Based on a Synergy of Scanning Lidar Systems

    NASA Astrophysics Data System (ADS)

    Wulfmeyer, V.; Turner, D. D.; Mauder, M.; Behrendt, A.; Ingwersen, J.; Streck, T.

    2015-12-01

    Improved simulations of land-surface-atmosphere interaction are fundamental for improving weather forecast and climate models. This requires observations of 2D fields of surface fluxes and the 3D structure of the atmospheric boundary layer simultaneously. A novel strategy is introduced for studying land-surface exchange and entrainment processes in the convective boundary layer (CBL) over complex terrain by means of a new generation of remote sensing systems. The sensor synergy consists of scanning Doppler lidar (DL), water-vapor differential absorption lidar (WVDIAL), and temperature rotational Raman lidar (TRRL) systems supported by surface in-situ measurements. The 2D measurements of surface fluxes are realized by the operation of a DL, a WVDIAL, and a TRRL along the same line-of-sight (LOS) in a range-height-indicator (RHI) mode whereas the other DL is performing a series of cross track RHI scans along this LOS. This new setup enables us to determine the friction velocity as well as surface sensible and latent heat fluxes by closing the complete set of Monin-Obukhov similarity relationships under a variety of surface layer stability conditions and different land cover and soil properties. As this closure is performed at all DL crossing points along the LOS, this is a strategy towards a 2D mapping of surface fluxes entirely based on remote sensing systems. Further details are presented at the conference. The second configuration is the simultaneous vertical profiling of vertical wind, humidity and temperature by DL, WVDIAL and TRRL so that latent heat and sensible heat flux profiles as well as a variety of different turbulent moments can be measured in the CBL. Consequently, by alternating of RHI scanning and vertical pointing modes, entrainment fluxes and surface fluxes can be measured almost simultaneously. This novel strategy has been realized for the first time during the Surface Atmospheric Boundary Layer Exchange (SABLE) campaign in the Kraichgau region

  19. Data processing and quality evaluation of a boat-based mobile laser scanning system.

    PubMed

    Vaaja, Matti; Kukko, Antero; Kaartinen, Harri; Kurkela, Matti; Kasvi, Elina; Flener, Claude; Hyyppä, Hannu; Hyyppä, Juha; Järvelä, Juha; Alho, Petteri

    2013-09-17

    Mobile mapping systems (MMSs) are used for mapping topographic and urban features which are difficult and time consuming to measure with other instruments. The benefits of MMSs include efficient data collection and versatile usability. This paper investigates the data processing steps and quality of a boat-based mobile mapping system (BoMMS) data for generating terrain and vegetation points in a river environment. Our aim in data processing was to filter noise points, detect shorelines as well as points below water surface and conduct ground point classification. Previous studies of BoMMS have investigated elevation accuracies and usability in detection of fluvial erosion and deposition areas. The new findings concerning BoMMS data are that the improved data processing approach allows for identification of multipath reflections and shoreline delineation. We demonstrate the possibility to measure bathymetry data in shallow (0-1 m) and clear water. Furthermore, we evaluate for the first time the accuracy of the BoMMS ground points classification compared to manually classified data. We also demonstrate the spatial variations of the ground point density and assess elevation and vertical accuracies of the BoMMS data.

  20. Data Processing and Quality Evaluation of a Boat-Based Mobile Laser Scanning System

    PubMed Central

    Vaaja, Matti; Kukko, Antero; Kaartinen, Harri; Kurkela, Matti; Kasvi, Elina; Flener, Claude; Hyyppä, Hannu; Hyyppä, Juha; Järvelä, Juha; Alho, Petteri

    2013-01-01

    Mobile mapping systems (MMSs) are used for mapping topographic and urban features which are difficult and time consuming to measure with other instruments. The benefits of MMSs include efficient data collection and versatile usability. This paper investigates the data processing steps and quality of a boat-based mobile mapping system (BoMMS) data for generating terrain and vegetation points in a river environment. Our aim in data processing was to filter noise points, detect shorelines as well as points below water surface and conduct ground point classification. Previous studies of BoMMS have investigated elevation accuracies and usability in detection of fluvial erosion and deposition areas. The new findings concerning BoMMS data are that the improved data processing approach allows for identification of multipath reflections and shoreline delineation. We demonstrate the possibility to measure bathymetry data in shallow (0–1 m) and clear water. Furthermore, we evaluate for the first time the accuracy of the BoMMS ground points classification compared to manually classified data. We also demonstrate the spatial variations of the ground point density and assess elevation and vertical accuracies of the BoMMS data. PMID:24048340

  1. Development of 2D Microdisplay Using an Integrated Microresonating Waveguide Scanning System

    PubMed Central

    Hua, Wei-Shu; Wang, Wei-Chih; Wu, Wen-Jong; Tsui, Chi Leung; Cui, Wei; Shih, Wen-Pin

    2012-01-01

    Our research team has developed a 2D micro image display device that can potentially overcome the size reduction limits while maintaining the high-image resolution and field of view obtained by mirror-based display systems. The basic design of the optical scanner includes a microfabricated SU-8 cantilever waveguide that is electromechanically deflected by a piezoelectric actuator. From the distal tip of the cantilever waveguide, a light beam is emitted and the direction of propagation is displaced along two orthogonal directions. The waveforms for the actuator and the LED light modulation are generated and controlled using a field programmable gate array. Our recent study is an update to the previously-reported mechanical scanner, replacing the hand-built PZT scanner and fiber waveguide with a microfabricated system incorporating aerosol-deposited PZT thin film and a polymeric SU-8 wave guide. In this article, we report on the design and fabrication of a prototype miniaturized 2D scanner, discuss optical and mechanical the modeling of the system’s properties and present the experimental results. PMID:22876080

  2. Control and acquisition systems for new scanning transmission x-ray microscopes at Advanced Light Source (abstract)

    NASA Astrophysics Data System (ADS)

    Tyliszczak, T.; Hitchcock, P.; Kilcoyne, A. L. D.; Ade, H.; Hitchcock, A. P.; Fakra, S.; Steele, W. F.; Warwick, T.

    2002-03-01

    Two new scanning x-ray transmission microscopes are being built at beamline 5.3.2 and beamline 7.0 of the Advanced Light Source that have novel aspects in their control and acquisition systems. Both microscopes use multiaxis laser interferometry to improve the precision of pixel location during imaging and energy scans as well as to remove image distortions. Beam line 5.3.2 is a new beam line where the new microscope will be dedicated to studies of polymers in the 250-600 eV energy range. Since this is a bending magnet beam line with lower x-ray brightness than undulator beam lines, special attention is given to the design not only to minimize distortions and vibrations but also to optimize the controls and acquisition to improve data collection efficiency. 5.3.2 microscope control and acquisition is based on a PC computer running WINDOWS 2000. All mechanical stages are moved by stepper motors with rack mounted controllers. A dedicated counter board is used for counting and timing and a multi-input/output board is used for analog acquisition and control of the focusing mirror. A three axis differential laser interferometer is being used to improve stability and precision by careful tracking of the relative positions of the sample and zone plate. Each axis measures the relative distance between a mirror placed on the sample stage and a mirror attached to the zone plate holder. Agilent Technologies HP 10889A servo-axis interferometer boards are used. While they were designed to control servo motors, our tests show that they can be used to directly control the piezo stage. The use of the interferometer servo-axis boards provides excellent point stability for spectral measurements. The interferometric feedback also provides active vibration isolation which reduces deleterious impact of mechanical vibrations up to 20-30 Hz. It also can improve the speed and precision of image scans. Custom C++ software has been written to provide user friendly control of the microscope

  3. Microwave scanning beam landing system compatibility and performance: Engineering analyses 75-1 and 75-2. [space shuttle orbiter landing

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The microwave scanning beam landing system (MSBLS) is the primary position sensor of the Orbiter's navigation subsystem during the autoland phase of the flight. Portions of the system are discussed with special emphasis placed on potential problem areas as referenced to the Orbiter's mission. Topics discussed include system compatability, system accuracy, and expected RF signal levels. A block and flow diagram of MSBLS system operation is included with a list of special tests required to determine system performance.

  4. VPI - VIBRATION PATTERN IMAGER: A CONTROL AND DATA ACQUISITION SYSTEM FOR SCANNING LASER VIBROMETERS

    NASA Technical Reports Server (NTRS)

    Rizzi, S. A.

    1994-01-01

    The Vibration Pattern Imager (VPI) system was designed to control and acquire data from laser vibrometer sensors. The PC computer based system uses a digital signal processing (DSP) board and an analog I/O board to control the sensor and to process the data. The VPI system was originally developed for use with the Ometron VPI Sensor (Ometron Limited, Kelvin House, Worsley Bridge Road, London, SE26 5BX, England), but can be readily adapted to any commercially available sensor which provides an analog output signal and requires analog inputs for control of mirror positioning. VPI's graphical user interface allows the operation of the program to be controlled interactively through keyboard and mouse-selected menu options. The main menu controls all functions for setup, data acquisition, display, file operations, and exiting the program. Two types of data may be acquired with the VPI system: single point or "full field". In the single point mode, time series data is sampled by the A/D converter on the I/O board at a user-defined rate for the selected number of samples. The position of the measuring point, adjusted by mirrors in the sensor, is controlled via a mouse input. In the "full field" mode, the measurement point is moved over a user-selected rectangular area with up to 256 positions in both x and y directions. The time series data is sampled by the A/D converter on the I/O board and converted to a root-mean-square (rms) value by the DSP board. The rms "full field" velocity distribution is then uploaded for display and storage. VPI is written in C language and Texas Instruments' TMS320C30 assembly language for IBM PC series and compatible computers running MS-DOS. The program requires 640K of RAM for execution, and a hard disk with 10Mb or more of disk space is recommended. The program also requires a mouse, a VGA graphics display, a Four Channel analog I/O board (Spectrum Signal Processing, Inc.; Westborough, MA), a break-out box and a Spirit-30 board (Sonitech

  5. Broadband Spectral-Polarimetric BRDF Scan System and Data for Spacecraft Materials

    NASA Astrophysics Data System (ADS)

    Bowers, D.; Wellems, L.; Duggin, M.; Glass, W.; Vaughn, L.

    2011-09-01

    A broadband spectral-polarimetric Bidirectional Reflectance Distribution Function (BRDF) measurement system from 350nm to 2500nm with 1nm wavelength resolution is providing data for satellite radiance modeling and specifically for Michigan Tech’s OCULUS-ASR space mission. The satellite has four deployable panels, which are covered with solar cells on one side, and are brightly colored on the other. BRDF data for the colored panels show interesting spectral features, including wavelength variability of first surface scatter, volumetric scatter and second surface scatter. Additional surface scatter data for other spacecraft materials including anodized aluminum, multilayer insulation (MLI) and solar cells is presented. The continuum nature of the data indicates that either dedicated BRDF models or a method for incorporating complex wavelength data into simulations will be needed for passive spectral radiance modeling and accurate spectral correlations.

  6. High Pressure Scanning Tunneling Microscopy Studies of AdsorbateStructure and Mobility during Catalytic Reactions: Novel Design of anUltra High Pressure, High Temperature Scanning Tunneling MicroscopeSystem for Probing Catalytic Conversions

    SciTech Connect

    Tang, David Chi-Wai

    2005-05-16

    The aim of the work presented therein is to take advantage of scanning tunneling microscope’s (STM) capability for operation under a variety of environments under real time and at atomic resolution to monitor adsorbate structures and mobility under high pressures, as well as to design a new generation of STM systems that allow imaging in situ at both higher pressures (35 atm) and temperatures (350 °C).

  7. Investigation of biological cell-protein interactions using SPR sensor through laser scanning confocal imaging-surface plasmon resonance system

    NASA Astrophysics Data System (ADS)

    Zhang, Hongyan; Yang, Liquan; Zhou, Bingjiang; Wang, Xueliang; Liu, Guiying; Liu, Weimin; Wang, Pengfei

    2014-03-01

    A new method for investigating biological cell-protein interactions was developed by using a laser scanning confocal imaging-surface plasmon resonance (LSCI-SPR) system. Mouse normal IgG was modified on the SPR chip. The suspension mouse lymphocyte cancer cells (L5178Y cells) labeled by Hoechst33342 freely flowed into the surface of the SPR sensor chip. By changing the concentration of the cells, the fluorescence images and the SPR signal were synchronously recorded in real time. The red fluorescence points in the imaging region increased with increase in the concentration of the mouse lymphocyte cancer cells and fit well with the change in the SPR signal. Different suspending cells were chosen to investigate cell-protein interactions through antigen-antibody reactions on the biological cell surfaces through binding detection. This method has potential application in cell biology and pharmacology.

  8. Volumetric rendering and metrology of spherical gradient refractive index lens imaged by angular scan optical coherence tomography system.

    PubMed

    Yao, Jianing; Thompson, Kevin P; Ma, Bin; Ponting, Michael; Rolland, Jannick P

    2016-08-22

    In this paper, we develop the methodology, including the refraction correction, geometrical thickness correction, coordinate transformation, and layer segmentation algorithms, for 3D rendering and metrology of a layered spherical gradient refractive index (S-GRIN) lens based on the imaging data collected by an angular scan optical coherence tomography (OCT) system. The 3D mapping and rendering enables direct 3D visualization and internal defect inspection of the lens. The metrology provides assessment of the surface geometry, the lens thickness, the radii of curvature of the internal layer interfaces, and the misalignment of the internal S-GRIN distribution with respect to the lens surface. The OCT metrology results identify the manufacturing defects, and enable targeted process development for optimizing the manufacturing parameters. The newly fabricated S-GRIN lenses show up to a 7x spherical aberration reduction that allows a significantly increased utilizable effective aperture.

  9. Evaluation of Fracture Resistance of Various Restorative Systems for Posterior Full Contour Restorations by Means of Scanning Technology

    NASA Astrophysics Data System (ADS)

    Dhima, Matilda

    Aims: The goals of this study were to: 1.) assess a range of the performance of four restorative systems for posterior single tooth crowns under single load to fracture submerged in an aqueous environment, 2.) identify restorative system(s) of interest to be examined under sliding contact step-stress fatigue as full contour anatomically appropriate single posterior tooth restoration(s) of various thicknesses submerged in water, 3.) assess a range of the performance of various thicknesses of restorative system(s) of interest. Material and Methods: A total of forty samples (n=10 each group) 2 mm uniform thickness were tested. Group 1. monolithic lithium disilicate IPS e.max Press; group 2. IPS e.max ZirPress, 0.8mm zirconia core with 1.2mm pressed veneering porcelain, group 3. IPS e.max ZirPress, 0.4mm zirconia core with 1.6mm pressed veneering porcelain, group 4. IPS InLine PoM. Samples were bonded to a block of polycast acrylic resin on a 30 degree sloped surface with resin cement. Samples were axially single loaded to failure while submerged under water. Findings from the testing were statistically analyzed and used to establish parameters for the material of interest to test submerged in aqueous environment under sliding contact step-stress fatigue as full contour single posterior restoration. This second phase assessed the performance of four groups (n=10 each group) of 0.5mm, 1.0mm, 1.5mm and 2.0mm of lithium disilicate restorations were tested. The tooth preparation for each sample was uniformly reduced, scanned digitally and milled for each group. The restorations were fabricated by scanning and milling technology. Results: There was a statistically significant difference (p< 0.001) in single failure load among the four restorative systems. Lithium disilicate showed a mean failure load similar to mean maximum posterior bite forces (743.1N +/- 114.3 N). This material was identified of interest to test submerged in aqueous environment under peak value force and

  10. Development of real-time line-scan hyperspectral imaging system for online agricultural and food product inspection

    NASA Astrophysics Data System (ADS)

    Yoon, Seung Chul; Park, Bosoon; Lawrence, Kurt C.; Windham, William R.; Heitschmidt, Gerald W.

    2010-04-01

    This paper reports a recent development of a line-scan hyperspectral imaging system for real-time multispectral imaging applications in agricultural and food industries. The hyperspectral imaging system consisted of a spectrograph, an EMCCD camera, and application software. The real-time multispectral imaging with the developed system was possible due to (1) data binning, especially a unique feature of the EMCCD sensor allowing the access to non-contiguous multispectral bands, (2) an image processing algorithm designed for real-time multispectral imaging, and (3) the design and implementation of the real-time application software. The imaging system was developed as a poultry inspection instrument determining the presence of surface feces on poultry carcasses moving at commercial poultry processing line speeds up to 180 birds per minute. The imaging system can be easily modifiable to solve other real-time inspection/sorting problems. Three wavelengths at 517 nm, 565 nm and 802 nm were selected for real-time fecal detection imaging. The fecal detection algorithm was based on dual band ratios of 565nm/517nm and 802nm/517nm followed by thresholding. The software architecture was based on a ping pong memory and a circular buffer for the multitasking of image grabbing and processing. The software was written in Microsoft Visual C++. An image-based internal triggering (i.e. polling) algorithm was developed to determine the start and end positions of birds. Twelve chickens were used for testing the imaging system at two different speeds (140 birds per minute and 180 bird per minute) in a pilot-scale processing line. Four types of fecal materials (duodenum, ceca, colon and ingesta) were used for the evaluation of the detection algorithm. The software grabbed and processed multispectral images of the dimension 118 (line scans) x 512 (height) x 3 (bands) pixels obtained from chicken carcasses moving at the speed up to 180 birds per minute (a frame rate 286 Hz). Intensity

  11. A scanning-mode 2D shear wave imaging (s2D-SWI) system for ultrasound elastography.

    PubMed

    Qiu, Weibao; Wang, Congzhi; Li, Yongchuan; Zhou, Juan; Yang, Ge; Xiao, Yang; Feng, Ge; Jin, Qiaofeng; Mu, Peitian; Qian, Ming; Zheng, Hairong

    2015-09-01

    Ultrasound elastography is widely used for the non-invasive measurement of tissue elasticity properties. Shear wave imaging (SWI) is a quantitative method for assessing tissue stiffness. SWI has been demonstrated to be less operator dependent than quasi-static elastography, and has the ability to acquire quantitative elasticity information in contrast with acoustic radiation force impulse (ARFI) imaging. However, traditional SWI implementations cannot acquire two dimensional (2D) quantitative images of the tissue elasticity distribution. This study proposes and evaluates a scanning-mode 2D SWI (s2D-SWI) system. The hardware and image processing algorithms are presented in detail. Programmable devices are used to support flexible control of the system and the image processing algorithms. An analytic signal based cross-correlation method and a Radon transformation based shear wave speed determination method are proposed, which can be implemented using parallel computation. Imaging of tissue mimicking phantoms, and in vitro, and in vivo imaging test are conducted to demonstrate the performance of the proposed system. The s2D-SWI system represents a new choice for the quantitative mapping of tissue elasticity, and has great potential for implementation in commercial ultrasound scanners.

  12. X-ray imaging of high velocity moving objects by scanning summation using a single photon processing system

    NASA Astrophysics Data System (ADS)

    Thim, J.; Reza, S.; O'Nils, M.; Norlin, B.

    2015-04-01

    X-ray imaging has been used extensively in the manufacturing industry. In the paper and paperboard industry X-ray imaging has been used for measuring parameters such as coat weight, using mean values of X-ray absorption inline in the manufacturing machines. Recently, an interest has surfaced to image paperboard coating with pixel resolved images showing material distribution in the coating on the paperboard, and to do this inline in the paper machine. Naturally, imaging with pixel resolution in an application where the paperboard web travels with velocities in the order of 10 m/s sets harsh demands on the X-ray source and the detector system to be used. This paper presents a scanning imaging method for single photon imaging systems that lower the demands on the source flux by hundreds of times, enabling a system to be developed for high velocity industrial measurement applications. The paper presents the imaging method, a discussion of system limitations, simulations and real measurements in a laboratory environment with a moving test object of low velocity, all to verify the potential and limits of the proposed method.

  13. Standard artifact for the geometric verification of terrestrial laser scanning systems

    NASA Astrophysics Data System (ADS)

    González-Jorge, H.; Riveiro, B.; Armesto, J.; Arias, P.

    2011-10-01

    Terrestrial laser scanners are geodetic instruments with applications in areas such as architecture, civil engineering or environment. Although it is common to receive the technical specifications of the systems from their manufacturers, there are not any solutions for data verification in the market available for the users. This work proposes a standard artifact and a methodology to perform, in a simple way, the metrology verification of laser scanners. The artifact is manufactured using aluminium and delrin, materials that make the artifact robust and portable. The system consists of a set of five spheres situated at equal distances to one another, and a set of seven cubes of different sizes. A coordinate measuring machine with sub-millimetre precision is used for calibration purposes under controlled environmental conditions. After its calibration, the artifact can be used for the verification of metrology specifications given by manufacturers of laser scanners. The elements of the artifact are destinated to test different metrological characteristics, such as accuracy, precision and resolution. The distance between centres of the spheres is used to obtain the accuracy data, the standard deviation of the top face of the largest cube is used to establish the precision (repeatability) and the error in the measurement of the cubes provides the resolution value in axes X, Y and Z. Methodology for the evaluation is mainly supported by least squares fitting algorithms developed using Matlab programming. The artifact and methodology proposed were tested using a terrestrial laser scanner Riegl LMSZ-390i at three different ranges (10, 30 and 50 m) and four stepwidths (0.002°, 0.005°, 0.010° and 0.020°), both for horizontal and vertical displacements. Results obtained are in agreement with the accuracy and precision data given by the manufacturer, 6 and 4 mm, respectively. On the other hand, important influences between resolution and range and between resolution and

  14. 3-D microvessel-mimicking ultrasound phantoms produced with a scanning motion system.

    PubMed

    Gessner, Ryan C; Kothadia, Roshni; Feingold, Steven; Dayton, Paul A

    2011-05-01

    Ultrasound techniques are currently being developed that can assess the vascularization of tissue as a marker for therapeutic response. Some of these ultrasound imaging techniques seek to extract quantitative features about vessel networks, whereas high-frequency imaging also allows individual vessels to be resolved. The development of these new techniques, and subsequent imaging analysis strategies, necessitates an understanding of their sensitivities to vessel and vessel network structural abnormalities. Constructing in-vitro flow phantoms for this purpose can be prohibitively challenging, because simulating precise flow environments with nontrivial structures is often impossible using conventional methods of construction for flow phantoms. Presented in this manuscript is a method to create predefined structures with <10 μm precision using a three-axis motion system. The application of this technique is demonstrated for the creation of individual vessel and vessel networks, which can easily be made to simulate the development of structural abnormalities typical of diseased vasculature in vivo. In addition, beyond facilitating the creation of phantoms that would otherwise be very challenging to construct, the method presented herein enables one to precisely simulate very slow blood flow and respiration artifacts, and to measure imaging resolution.

  15. A 2-D Microdisplay Using An Integrated Microresonating Waveguide Scanning System

    PubMed Central

    Hua, Wei-Shu; Tsui, Chi Leung; Soetanto, William; Wu, Wen-Jong; Wang, Wei-Chih

    2012-01-01

    Our research team has developed a MEMS based on a 2D micro image display device that can potentially overcome the size reduction limits while maintaining the high image resolution and field of view obtained by mirror based display systems. The basic design of the optical scanner includes a micro-fabricated polymer based cantilever waveguide that is electromechanically deflected by a 2D piezoelectric actuator. From the distal tip of the cantilever waveguide, a light beam is emitted and the direction of propagation is displaced along two orthogonal directions. The waveforms for the X-Y actuators and the LED light modulation are controlled using a field programmable gate array (FPGA). In this paper we will extend our display development by reporting more recent integration of components including actuators and light sources with a controller. Here we will describe the design, fabrication of the latest polymeric waveguide cantilever beam steering device driven by 2-D piezoelectric actuator using aerosol deposited PZT thick film actuators. The mechanical and optical design for the microresonating scanner will be discussed. In addition, the mechanical and optical performance of the 2-D scanner will be presented. PMID:26726320

  16. Advanced compact laser scanning system enhancements for gear and thread measurements. Final CRADA report

    SciTech Connect

    McKeethan, W.M.; Maxey, L.C.; Bernacki, B.E.; Castore, G.

    1997-04-04

    The measurement, or metrology, of physical objects is a fundamental requirement for industrial progress. Dimensional measurement capability lies at the heart of ones ability to produce objects within the required technical specifications. Dimensional metrology systems are presently dominated by touch-probe technologies, which are mature and reliable. Due to the intricate geometries required in certain fields of manufacturing, these contract probes cannot be physically brought in proximity to the measurement surface, or lack sufficient lateral resolution to satisfactorily determine the surface profile, which can occur in the measurement of gears, splines and thread. Optical probes are viable candidates to supplement the contact probes, since light can be focused to less than one micron (40 microinches), no contact occurs that can mar highly finished surfaces, and no probes must be replaced due to wear. However, optical probes typically excel only on one type of surface: mirror-like or diffuse, and the optical stylus itself is oftentimes not as compact as its contact probe counterpart. Apeiron, Inc. has pioneered the use of optical non-contact sensors to measure machined parts, especially threads, gears and splines. The Oak Ridge Metrology Center at Oak Ridge Y-12 Plant are world-class experts in dimensional metrology. The goal of this CRADA is to tap the expertise in Oak Ridge to evaluate Apeiron`s platform, and to suggest new or novel methods of optical surface sensing, if appropriate.

  17. Software system for three-dimensional visualization of micro-object surfaces for scanning probe microscopy using OpenGL graphics library

    NASA Astrophysics Data System (ADS)

    Vakuliuk, Nickolay V.

    2002-07-01

    The software system for 3D visualization of micro objects surfaces for scanning probe microscopy is developed. The system is used as a software part of software/hardware complex of scanning probe microscope (SPM) and its kinds. The system represent the results of microscope work in 3D- view. System has convenient GUI and high level of functionality in modes of visualization and in saving result images. Program allows to operate with image of surface in real time by performing scaling, rotation, moving, setting of lighting and color values, setting level of detail for surface in real time by performing scaling, rotation, moving, setting of lighting and color values, setting level of detail for surface rendering. This viewer works together with another part of software system that is responsible for controlling the SPM. The program also can be used as an independent view of scanning probe microscope files.

  18. A Scanning electron microscopic evaluation of intracanal smear layer removal by two different final irrigation activation systems

    PubMed Central

    Dua, Deepti; Dua, Ankur; Uppin, Veerendra M.

    2014-01-01

    Aim: The aim of this study was to compare smear layer removal at apical 1 mm level after final irrigation activation with an EndoVac system and Max-I probe. Materials and Methods: Fifty freshly extracted maxillary central incisors were randomly divided into two groups after completing cleaning and shaping with ProTaper rotary files. In one group, final irrigation was performed with an EndoVac system while in the other group final irrigation was performed with a 30 gauge Max-I probe. 3% sodium hypochlorite and 17% ethylenediaminetetracetic acid were used as final irrigants in all teeth. After instrumentation and irrigation, the teeth were sectioned longitudinally into buccal and palatal halves and viewed under a scanning electron microscope for evaluation of the smear layer. Statistical analysis was performed using the Kruskal Wallis and Mann-Whitney U tests. Results: The EndoVac group showed significantly better smear layer removal compared with the Max-I probe at the apical 1 mm level. Conclusion: An apical negative pressure system (EndoVac) results in better debridement at apical 1 mm when compared with side-vented closed ended needle irrigation (Max-I probe). PMID:24808693

  19. The Scanning Process: Getting Started.

    ERIC Educational Resources Information Center

    Renfro, William L.; Morrison, James L.

    1983-01-01

    Scanning the external environment will become more essential to colleges in the coming decade. Developing an environmental scanning system can identify important emerging issues that may constitute either threats or opportunities. The organizational features of a mature scanning process are described. (MLW)

  20. Acquisition of a Scanning Laser Vibrometer System for Experimental Studies on Nonparametric Nonlinear System Identification and Aeroelastic Instability Suppression

    DTIC Science & Technology

    2011-03-06

    based LCO suppression system housed in a winglet , specifically designed for the GTW. Upon completion of rehabilitation and modifications to the wing to...accommodate the winglet /NES, the full system will be ready for additional testing in the TDT. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF...University, will result in the design of an NES-based LCO suppression system housed in a winglet , specifically designed for the GTW. Upon completion of