scholarly journals Resolving tissue chromophore concentration at MRI resolution using multi-wavelength photo-magnetic imaging

2020 ◽  
Vol 11 (8) ◽  
pp. 4244
Author(s):  
Maha Algarawi ◽  
Hakan Erkol ◽  
Alex Luk ◽  
Seunghoon Ha ◽  
Mehmet B. Ünlü ◽  
...  
Keyword(s):  
Magnetic Imaging ◽  
Chromophore Concentration ◽  
Multi Wavelength

High-resolution chromophore concentration recovery using multi-wavelength photo-magnetic imaging

2019 ◽  
Author(s):  
Farouk Nouizi ◽  
Seunghoon Ha ◽  
Maha Algarawi ◽  
Alex Luk ◽  
Mehrnaz Mehrabi ◽  
...  
Keyword(s):  
High Resolution ◽  
Magnetic Imaging ◽  
Chromophore Concentration ◽  
Multi Wavelength

Multi‐Wavelength Photo‐Magnetic Imaging System for Photothermal Therapy Guidance

2020 ◽  
Author(s):  
Maha Algarawi ◽  
Hakan Erkol ◽  
Alex Luk ◽  
Seunghoon Ha ◽  
Mehmet Burcin Unlu ◽  
...  
Keyword(s):  
Photothermal Therapy ◽  
Imaging System ◽  
Magnetic Imaging ◽  
Multi Wavelength

Zero-loss omega-filtered REM and RHEED on the new Zeiss 912

1991 ◽  
Vol 49 ◽  
pp. 616-617
Author(s):  
J.C.H. Spence ◽  
J. Mayer
Keyword(s):  
Electron Microscopy ◽  
Materials Science ◽  
Surface States ◽  
Ccd Camera ◽  
Dark Field ◽  
Ion Pump ◽  
Magnetic Imaging ◽  
Reflection Electron Microscopy ◽  
Diffraction Patterns ◽  
Large Background

The Zeiss 912 is a new fully digital, side-entry, 120 Kv TEM/STEM instrument for materials science, fitted with an omega magnetic imaging energy filter. Pumping is by turbopump and ion pump. The magnetic imaging filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient parallel (area) detection. The energy loss intensity distribution may also be displayed on the screen, and recorded by scanning it over the PMT supplied. If a CCD camera is fitted and suitable new software developed, “parallel ELS” recording results. For large fields of view, filtered images can be recorded much more efficiently than by Scanning Reflection Electron Microscopy, and the large background of inelastic scattering removed. We have therefore evaluated the 912 for REM and RHEED applications. Causes of streaking and resonance in RHEED patterns are being studied, and a more quantitative analysis of CBRED patterns may be possible. Dark field band-gap REM imaging of surface states may also be possible.

Electron spectroscopic imaging and diffraction

1991 ◽  
Vol 49 ◽  
pp. 706-707
Author(s):  
M. Rühle ◽  
J. Mayer ◽  
J.C.H. Spence ◽  
J. Bihr ◽  
W. Probst ◽  
...  
Keyword(s):  
Materials Science ◽  
Electron Spectroscopic Imaging ◽  
Magnetic Filter ◽  
Magnetic Imaging ◽  
Illumination System ◽  
Probe Size ◽  
Diffraction Patterns ◽  
Fritz Haber ◽  
Koehler Illumination ◽  
First Time

A new Zeiss TEM with an imaging Omega filter is a fully digitized, side-entry, 120 kV TEM/STEM instrument for materials science. The machine possesses an Omega magnetic imaging energy filter (see Fig. 1) placed between the third and fourth projector lens. Lanio designed the filter and a prototype was built at the Fritz-Haber-Institut in Berlin, Germany. The imaging magnetic filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient area detection. The energy dispersion at the exit slit (Fig. 1) results in ∼ 1.5 μm/eV which allows imaging with energy windows of ≤ 10 eV. The smallest probe size of the microscope is 1.6 nm and the Koehler illumination system is used for the first time in a TEM. Serial recording of EELS spectra with a resolution < 1 eV is possible. The digital control allows X,Y,Z coordinates and tilt settings to be stored and later recalled.

Observations for the Role of Flux rope Eruption in a Geoeffective Solar Flare

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam
Keyword(s):  
Solar Flare ◽  
Flux Rope ◽  
Magnetic Configuration ◽  
Solar Dynamics Observatory ◽  
Multi Wavelength ◽  
Solar Dynamics ◽  
Halo Coronal Mass Ejection ◽  
Mass Ejection ◽  
The Waves

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.

Multi-wavelength imaging and its application as a plasma torch health monitor

1997 ◽  
Author(s):  
C. Winstead ◽  
W. Wang ◽  
R. Cook ◽  
G. Miller ◽  
C. Winstead ◽  
...  
Keyword(s):  
Plasma Torch ◽  
Multi Wavelength ◽  
Health Monitor

Choice of Optimum Operational Regime for Total Stations upon Making Geodetic Surveys under Heavy Aerosol Atmosphere Pollution

2018 ◽  
Vol 938 (8) ◽  
pp. 12-19
Author(s):  
S. B. Verdiyev
Keyword(s):  
Rational Choice ◽  
Theoretical Modelling ◽  
Total Station ◽  
Visible Band ◽  
Multi Wavelength ◽  
Atmosphere Pollution ◽  
Experimental Researches ◽  
Practical Recommendations

The possibility to use multi-wavelength regime of total stations operation for making surveys under heavy aerosol atmosphere pollution is researched. The actuality of single- and multi-wavelength regimes rational choice under heavy aerosol atmosphere pollution is grounded. The task on researching the matter of operational regime choice for total stations is formulated. The method for solution of the formulated task is suggested. The theoretical modelling and experimental researches are held to formulate the criterion for choice of single- or multi-wavelength regimes. The practical recommendations for such a choice are formulated. The practical recommendations are formulated for choice of measurements regime. According to formulated recommendations if a single-wavelength total station operates in the field of longer wavelengths (R) of visible band and a three-wavelengths one operates with bias to shorter (B, G, R) wavelengths, the single-wavelength total station should be preferred. But if the single-wavelength total station operates in the field of shorter wavelengths (B) and the three-wavelengths one operates with bias to longer wavelengths (B, G, R) then the multi-wavelengths total station should be preferred. The recommendation described in this article are relevant for both the regimes of measurements with- and without reflector and can be useful for users of total stations.

scholarly journals Classification of Tree Species as Well as Standing Dead Trees Using Triple Wavelength ALS in a Temperate Forest

2019 ◽  
Vol 11 (22) ◽  
pp. 2614 ◽  
Author(s):  
Nina Amiri ◽  
Peter Krzystek ◽  
Marco Heurich ◽  
Andrew Skidmore
Keyword(s):  
Tree Species ◽  
Feature Selection Method ◽  
Silver Fir ◽  
Maximum Point ◽  
Individual Tree ◽  
Dead Trees ◽  
Multi Wavelength ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
532 Nm

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.

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