phase mapping

Top PDF phase mapping:

2D and 3D phase mapping of laser interacted interferograms

2D and 3D phase mapping of laser interacted interferograms

Phase mapping is a fast, efficient and accurate method for phase measurement of an interferogram. This technique relies on digitizing the intensity distribution of the whole area of the interferogram [1-2]. However, a problem with the technique is that, quite often this technique is plagued with phase ambiguity, especially when measurement is made on a single interferogram [3]. In order to find a good suitable interferogram, we must capture the interferogram again and again until we produce a good enough interferogram that can be assessed. Due to the sensitive nature of laser interferometry, this could lead to other in-situ problems. Phase mapping the interferogram would involve noise filtering, phase wrapping and phase unwrapping. This would enable the observer to have a direct 2D and 3D view of very small physical changes occurring in the event.
Show more

8 Read more

Self-Navigated Tissue Phase Mapping Using a Golden-Angle Spiral Acquisition-Proof of Concept in Patients with Pulmonary Hypertension

Self-Navigated Tissue Phase Mapping Using a Golden-Angle Spiral Acquisition-Proof of Concept in Patients with Pulmonary Hypertension

Magnetic resonance tissue phase mapping (TPM) allows assessment of the separate directional components of wall motion, as well as their regional distribution. However, the requirement for velocity encoding in all three directions results in long acquisition times. This is particularly true when imaging the thin walled right ventricle (RV), as higher spatial-resolution is also required. Thus, the majority of TPM implementations are acquired during free-breathing, with respiratory navigators used to reduce respiratory motion artifacts (1-3).

28 Read more

Acceleration of tissue phase mapping with sensitivity encoding at 3T

Acceleration of tissue phase mapping with sensitivity encoding at 3T

Parallel imaging techniques exploiting coil sensitivities for unaliasing like sensitivity encoding (SENSE) [25] and generalized auto-calibrating partially parallel acquisitions (GRAPPA) [26] enable high acceleration factors. No temporal smoothing is expected. The aim of this work was to quantify the feasibility of using SENSE for tissue phase mapping of the left ventricle. An analysis of the influence of SENSE on TPM based flow quantification was performed and investigated for different accelerating factors. A case example is added to show the possibility of the combination of SENSE with TPM to measure the left-ventricular myocardial motion in 3D.
Show more

13 Read more

Neutron Bragg Edge Tomography for Phase Mapping

Neutron Bragg Edge Tomography for Phase Mapping

structural properties and their state of stress, is of tremendous significance and interest. Established characterization techniques for example include light microscopy (metallography), electron microscopy (transmission electron microscopy and scanning electron microscopy), electron backscatter diffraction (EBSD) and (laboratory) X-ray diffraction. However, all of these techniques are mostly limited to evaluating the surface features and require the sample to be extracted from the bulk requiring destructive specimen preparation approach and only represent small volume observed that is no longer in an undisturbed state. Hard X-rays (for example at a synchrotron source) can penetrate deep into most metals, with certain limitations (Hutchings et al., 2005). While X-rays and electrons interact with the electrons of an atom, neutrons interact with the nucleus and hence neutron radiation provides the ability to penetrate deep into most structural materials. As such, neutron diffraction for instance is considered the only true bulk investigation technique for stress and strain measurements (Allen et al., 1985; Hutchings et al., 2005; Clausen et al., 2003). Electron and X-ray based imaging techniques are very popular amongst scientists and engineers as they provide spatial information, and through a combination with scattering and diffraction modes have evolved to be very powerful and versatile characterization and analysis tools. This makes it possible to perform chemical analysis (Energy-dispersive X-ray spectroscopy, EDS (Goldstein et al., 2003)) and enables crystallographic investigations for grain, strain and phase mapping (EBSD (Goldstein et al., 2003)). It should be noted that especially in the field of diffraction-based imaging using (synchrotron) X-rays, tremendous advances have been made within the last decade for non-destructive three-dimensional (3D) microstructural characterization of crystalline materials, notably differential-aperture X-ray microscopy (DAXM; (Larson et al., 2002)), 3D-X-ray diffraction (3D-XRD; (Poulsen, 2004)) and Diffraction Contrast Tomography (DCT; (Ludwig et al., 2009)). However, even these techniques are still limited to relatively small size sample while neutrons are optimal for bulk investigations (Banhart, 2008). Characterizing the bulk properties is crucial to understanding the meso-scale effects for polycrystalline materials (Doherty et al., 1997).
Show more

10 Read more

Analyzing myocardial torsion based on tissue phase mapping cardiovascular magnetic resonance

Analyzing myocardial torsion based on tissue phase mapping cardiovascular magnetic resonance

Previous studies have attempted to quantify myocar- dial torsion using tissue Doppler imaging [8], or speckle tracing echocardiography [9]. However, Doppler imaging cannot measure velocity in three dimensions and for all cardiac segments. Speckle tracking, while overcoming the previous limitations, is highly dependent on the acoustic window. Cardiovascular magnetic resonance (CMR) is a powerful alternative for analyzing local myo- cardial deformation. Based on MR-Tagging [10, 11], the rapid and complex rotational motion pattern and the endo- versus epicardial differences of the heart muscle are difficult to quantify due to the low spatial resolution. Displacement-encoded image using stimulated echoes (DENSE) [12] and Tissue Phase Mapping (TPM) [13] can measure local motion with higher temporal (DENSE) and spatial (TPM) resolution respectively. Moreover, TPM directly measures myocardial velocities and allows for their quantitative assessment along all three principal motion directions of the heart (radial, long-axis, circumferential). Acceleration plays an import- ant role to make high resolution TPM acquisition pos- sible during breath hold. Existing methods employ spatio-temporal imaging acceleration k-t GRAPPA [14] (required breath hold: 25 heartbeats) and non-Cartesian SENSE implemented on the GPU [15] (required breath hold: 13–17 heartbeats).
Show more

13 Read more

Left ventricular diastolic dysfunction in pulmonary hypertension predicts functional capacity and clinical worsening: a tissue phase mapping study

Left ventricular diastolic dysfunction in pulmonary hypertension predicts functional capacity and clinical worsening: a tissue phase mapping study

produce low temporal resolution (315 ms) real-time images. These real-time data are used to create an image based respiratory navigator, used to select 30 % of the expiratory spiral interleaves for the final retro- spectively cardiac-gated reconstruction. Sequence pa- rameters: TE/TR 3.85/14.9 ms, FOV 450 mm, Matrix: 384 × 384, uniformly distributed spiral interleaves re- quired to fill k-space: 30 (for each of the three phase- encoded directions), slice thickness: 7 mm, VENC: 30 cm/s, Flip angle: 25°, pixel bandwidth: 930 Hz/pixel. This achieved a temporal resolution of 27.14 ms, with a spatial resolution 1.17 × 1.17 mm, giving approxi- mately 40 cardiac phases. The nominal scan time, as- suming a heart rate of 60 bpm and 100 % respiratory efficiency, would be 1 min 30 s, resulting in a scan time of approximately 4 to 5 min per subject depend- ing upon heart rate. TPM data were acquired in mid- ventricular short-axis, which was chosen by reference to a 4-chamber cine at end-systole.
Show more

11 Read more

Workplace mapping. Mapping a workplace the benefits. Mapping is the most effective way to:

Workplace mapping. Mapping a workplace the benefits. Mapping is the most effective way to:

Mapping is an ongoing process – maps change with the workplace. If done properly your map will become an important and invaluable tool for identifying areas of work. It will show you weak areas of membership or departments where you need to develop reps and activists. And it will help you identify activists and new recruits. Once you have recruited or developed reps, these changes will be added to the map, which will then highlight new priorities for you.

8 Read more

Three-Dimensional Visualisation of Gas-water Two-phase Flow Based on Bubble Mapping Method and Size Projection Algorithm

Three-Dimensional Visualisation of Gas-water Two-phase Flow Based on Bubble Mapping Method and Size Projection Algorithm

Electrical impedance tomography (EIT) has been successfully applied on gas-water fl ow applications, but it is incapable to identify small bubbles or the sharp gas-water interface of a large bubble due to its relatively low spatial resolution. A new visualisation approach, bubble mapping method (BM3D), o ff ers a good 3D visualisation of bubble size and distribution. However, the empirical thresholding value method used in BM3D might meet a challenging from various flow setups and conditions in practice. Recently, the size projection algorithm (SPA) was proposed to determine the closest thresholding value for each frame of tomogram by minimising projection error. In this paper, the performances of BM3D and SPA methods are individually analysed and evaluated. Then a new method based on the combination of BM3D and SPA methods is reported to achieve better visualisation of gas-water fl ow, where the SPA is employed to determine the optimised thresholding values for BM3D method. Experiments are conducted to evaluate the proposed combination method for typical gas-water pipeline fl ow regimes, including horizontal stratified, bubble, plug, slug, annular flow regimes and vertical bubble, slug, annular fl ow regimes. The results are compared with the BM3D method, colour mapping method, and high- speed camera video recorded from a transparent chamber. A brief discussion on the e ff ects of reconstruction algorithms and thresholding value for horizontal and vertical flows visualisation is also given.
Show more

10 Read more

S: Hbe a nonlinear mapping. The mapping

S: Hbe a nonlinear mapping. The mapping

Theorem 3.1 Let H be a real Hilbert space, let F be a bifunction from C C × into H satisfying the conditions (A1)- (A4) and let { } S n is a sequence of nonexpansive mappings on C. Let A : H → H is an α − inverse strongly monotone mapping and B : C → H is a δ − inverse strongly monotone mapping. Let M : H → 2 H is maximal monotone mapping such that

5 Read more

Two Phase Ontology Mapping Approach

Two Phase Ontology Mapping Approach

Having obtained the semantic knowledge and represented them via ontologies, the next step is mapping these ontologies and finally querying the semantic data, also known as semantic search. From the query interface form all the fields are taken and represented through a graph data structure which is utilized to in for mapping purposes. Here we have taken an example of book-domain ontologies.

7 Read more

A multi center inter manufacturer study of the temporal stability of phase contrast velocity mapping background offset errors

A multi center inter manufacturer study of the temporal stability of phase contrast velocity mapping background offset errors

GE Signa Excite at VUMC Amsterdam NL, and Adden- brooke’s Hospital Cambridge, UK. The readout ADC bandwidth was 41.67 kHz (pixel bandwidth 326 Hz/pixel). This used symmetric velocity-encoding (i.e. two sequence repetitions with positive and negative velocity sensitivities around the velocity-compensated waveform, also known as “balanced” velocity-encoding). The “flow analysis” flag was on, disabling a spatial high-pass filter used for phase- contrast angiography background suppression. The GE “flow optimization” control resulted in longer TE and TR than the other scanners and was therefore not used. Twenty cardiac phases were reconstructed in a 600 ms simulated R-R interval (i.e. temporal interpolation was applied by reconstruction).
Show more

7 Read more

Longitudinally and circumferentially directed movements of the left ventricle studied by cardiovascular magnetic resonance phase contrast velocity mapping

Longitudinally and circumferentially directed movements of the left ventricle studied by cardiovascular magnetic resonance phase contrast velocity mapping

counterclockwise at the beginning of systole, resulting in little gradient between the LV base and apex, with the torsion rate close to zero (a). Subsequently, as the LV base rotates in a clockwise direction, the ventricular torsion rate increases, reaching its peak value at the end of rapid ejection (b). Then, as the clockwise velocities of the ventricular base fall during the phase of reduced ejection, the ventricular torsion rate similarly declines. Repolarization was followed by a sudden onset of ventricular untwisting, reflected in a negative ventricular torsion rate (c). Subsequent smaller negative waves of the ventricular torsion rate (d, e, f ) likely correspond to slightly different peaks of ventricular untwisting at the LV base and apex.
Show more

8 Read more

Micro Raman Mapping of 3C SiC Thin Films Grown by Solid–Gas Phase Epitaxy on Si (111)

Micro Raman Mapping of 3C SiC Thin Films Grown by Solid–Gas Phase Epitaxy on Si (111)

Abstract A series of 3C-SiC films have been grown by a novel method of solid–gas phase epitaxy and studied by Raman scattering and scanning electron microscopy (SEM). It is shown that during the epitaxial growth in an atmosphere of CO, 3C-SiC films of high crystalline quality, with a thickness of 20 nm up to few hundreds nanometers can be formed on a (111) Si wafer, with a simultaneous growth of voids in the silicon substrate under the SiC film. The presence of these voids has been confirmed by SEM and micro-Raman line-mapping experiments. A significant enhancement of the Raman signal was observed in SiC films grown above the voids, and the mechanisms responsible for this enhancement are discussed.
Show more

5 Read more

Counter (Mapping) Actions: Mapping as Militant Research

Counter (Mapping) Actions: Mapping as Militant Research

Through that Labor Day drift and subsequent conversations, we began to understand our own work in the university. Our research, writing, and teaching are productive labors and indicative of broader economic shifts. This work falls into the category of immaterial labor: labor that produces the informational, cultural, communicative, and affective aspects of commodities (Lazzarato, 1996; Shukaitis and Graeber, 2007). This labor is spatially organized very differently from Fordist labor: no longer centered in the factory, or even an official workplace, immaterial labor is geographically diffuse, occurring in all of the spaces we occupy on a daily basis. The lack of a common space makes organizing these workers a difficult task, a difficulty to which mapping is the perfect response. Counter-mapping identifies the sites where immaterial labor takes place and creates a common space of encounter, bringing workers together to share the experiences of their labor. Acknowledging our situation as workers helped us see ourselves in solidarity with other workers and opened the door to further mappings of UNC-Chapel Hill.
Show more

28 Read more

Mapping Digitally, Mapping Deep:Exploring Digital Literary Geographies

Mapping Digitally, Mapping Deep:Exploring Digital Literary Geographies

true to the digital study of literary geography, which “challenges literary studies to move beyond close, or even distant, readings” by embracing more fluid and dialectic interpretative approaches (Whitson, 5). Digital literary geography – and, specifically, the digital cartographies that are its main expression – encourage precisely such an approach. They are capable of challenging traditional hierarchies of research practice, generating new modes of knowledge production and advancing new means of expression. In recent years, these modes have taken a number of forms, from the sort of location aware media experience developed by projects like James Loxley’s Palimpsest: Literary Edinburgh, to desktop-based mapping environments, such as Matthew Sangster’s Romantic London. 1 In addition to these resources, scholars have also continued
Show more

14 Read more

Mapping History

Mapping History

In this thesis titled Mapping History archaeological sites within a small region in the northwestern Dominican Republic are mapped, in order to distinguish patterns in site locations and to explore the social landscape in the past. The landscape in the research area consists of beaches, swamps, mangroves, valleys, and hills up to 300 metres in height. It is known from research by Jorge Ulloa Hung, an archaeologist currently writing his dissertation on ceramics in the area, that there were different ceramic styles present contemporaneously in the north of the Dominican Republic. While Ulloa Hung focuses on the ceramics from the sites in the area, in this research the surrounding area (circa 80 km²) is mapped to provide a context for Ulloa Hung’s research. In this thesis the study on the social landscape is the central focus. Observations and results of the fieldwork conducted in the area were used for this study, and recorded into a map-related database or Geographical Information System (GIS). The relation between site locations and surroundings were analysed with the use of the created GIS. The focus of the analyses is mainly on differences between sites with Meillacoid style ceramics and sites with Chicoid style ceramics. The goal was to bring forth different patterns in the site locations of Meillacoid and Chicoid sites. The diverse landscape in the area combined with the diverse cultural landscape makes this area very suitable for such analyses. Although there are similarities between several aspects of the sites, the area also differences. Meillacoid sites tend to be located closer to the coast, while Chicoid sites are located further inland. Furthermore, Meillacoid sites have a better visibility range, and are therefore better visible themselves. There are evidently different patterns of site locations of both kinds of sites in the area, but there is one common denominator: diversity.
Show more

125 Read more

Competency Mapping

Competency Mapping

“THE HINDU” dated Wednesday, Nov 30, 2005 has explained the meaning of competency mapping and its process as, What does `Competency Mapping' really mean? Competency Mapping is a process of identifying key competencies for a company or institution and the jobs and functions within it. To make it even clearer, we could say that a competency is a behavior (i.e. communication, leadership) rather than a skill or ability although it sometimes includes skills and abilities. Clear? I thought not! Perhaps if we were to look at the steps involved in the process:
Show more

7 Read more

Single Phase to Three Phase Converter

Single Phase to Three Phase Converter

We are giving 230v supply to rectifier, during positive half of input two diode are triggered and for negative half of input another two diode are trigger and AC supply is converted to DC. In inverting stage we using six IGBT as inverter. Upper side three IGBT are called as positive group IGBT and lower side three IGBT are called as negative group IGBT. IGBT work in 120 degree mode of operation in which one IGBT from positive group and another two from negative group and after that one from negative group another from positive group. Same procedure is followed by whole inverter circuit. Diodes are connect across each IGBT to limit the reverse current flowing through the inverter. In this way we getting the three phase from middle of two IGBTs.
Show more

7 Read more

Scoping Phase; Specialist Study Phase; and Integration and Assessment Phase.

Scoping Phase; Specialist Study Phase; and Integration and Assessment Phase.

During the Specialist Study phase, the appointed specialists gathered data relevant to identifying and assessing environmental impacts that might occur as a result of the Project. They assisted the project team in assessing potential impacts according to a predefined assessment methodology included in the Scoping Report. Specialists have also suggested ways in which negative impacts could be mitigated and benefits could be enhanced.

15 Read more

Consensus Mapping and Association Mapping in Hexaploid Oat.

Consensus Mapping and Association Mapping in Hexaploid Oat.

differentiating ‘HiFi’ and ‘SolFi’ , respectively. This region was PCR-amplified in mapping parents ‘HiFi’ and ‘SolFi’ and 51 RILs of the HiFi x SolFi mapping population using HotStart Taq Master Mix Kit (Qiagen, Valencia, CA). PCR products were purified with exonuclease I and antarctic phosphatase (New England Biolabs Inc., Ipswich, MI) and directly Sanger-sequenced using the same primers. Sequences were assembled in Geneious and genotypes were determined by manual inspection. The HiFi x SolFi population was chosen first, because the parents had a polymorphism at the desired SRR as well as the map had previously been genotyped to assist in the development of a SNP linkage map for physical anchoring of oat chromosomes (Chaffin et al., 2016; Oliver et al., 2013). In addition the parents of this population vary phenotypically in regards to β-glucan content, ‘HiFi’ containing high levels of β-glucan, while ‘SolFi’ produces
Show more

141 Read more

Show all 10000 documents...