Uncovering the remarkable contribution of lasers peak intensity region in holography

2021 ◽  
Vol 18 (8) ◽  
pp. 086003
Author(s):  
Lohit Malik ◽  
Alexandre Escarguel ◽  
Mayank Kumar ◽  
Abhishek Tevatia ◽  
Rajpal Singh Sirohi
Author(s):  
J. S. Wall ◽  
J. P. Langmore ◽  
H. Isaacson ◽  
A. V. Crewe

The scanning transmission electron microscope (STEM) constructed by the authors employs a field emission gun and a 1.15 mm focal length magnetic lens to produce a probe on the specimen. The aperture size is chosen to allow one wavelength of spherical aberration at the edge of the objective aperture. Under these conditions the profile of the focused spot is expected to be similar to an Airy intensity distribution with the first zero at the same point but with a peak intensity 80 per cent of that which would be obtained If the lens had no aberration. This condition is attained when the half angle that the incident beam subtends at the specimen, 𝛂 = (4𝛌/Cs)¼


Author(s):  
Mihir Parikh

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used


2020 ◽  
Vol 9 (1-2) ◽  
pp. 89-100 ◽  
Author(s):  
Xinyu Hu ◽  
Rui Pan ◽  
Mingyong Cai ◽  
Weijian Liu ◽  
Xiao Luo ◽  
...  

AbstractEvaporation concentration of target analytes dissolved in a water droplet based on superhydrophobic surfaces could be able to break the limits for sensitive trace substance detection techniques (e.g. SERS) and it is promising in the fields such as food safety, eco-pollution, and bioscience. In the present study, polytetrafluoroethylene (PTFE) surfaces were processed by femtosecond laser and the corresponding processing parameter combinations were optimised to obtain surfaces with excellent superhydrophobicity. The optimal parameter combination is: laser power: 6.4 W; scanning spacing: 40 μm; scanning number: 1; and scanning path: 90 degree. For trapping and localising droplets, a tiny square area in the middle of the surface remained unprocessed for each sample. The evaporation and concentration processes of droplets on the optimised surfaces were performed and analyzed, respectively. It is shown that the droplets with targeted solute can successfully collect all solute into the designed trapping areas during evaporation process on our laser fabricated superhydrophobic surface, resulting in detection domains with high solute concentration for SERS characterisation. It is shown that the detected peak intensity of rhodamine 6G with a concentration of 10−6m in SERS characterisation can be obviously enhanced by one or two orders of magnitude on the laser fabricated surfaces compared with that of the unprocessed blank samples.


1994 ◽  
Vol 42 (3) ◽  
pp. 231-241 ◽  
Author(s):  
C. Shenberg ◽  
S. Spiegel ◽  
S. Chaitchik ◽  
P. Jordan ◽  
M. Kitzis ◽  
...  

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Mpho Phillip Motloung ◽  
Simphiwe Zungu ◽  
Vincent Ojijo ◽  
Jayita Bandyopadhyay ◽  
Suprakas Sinha Ray

Abstract This study examines the influence of cellulose nanocrystal (CN) particles on the morphological, thermal, and thermo-mechanical properties of polylactide (PLA)/poly [(butylene succinate)-co-adipate] (PBSA) blend foams prepared by casting and particulate leaching method using fructose as porogen particles. The morphological analysis showed an interconnected open-cell structure, with porosity above 80%. The crystallinity of the prepared foams was disrupted by the inclusion of CN particles as observed from XRD analyses, which showed a decrease in PLA crystal peak intensity. With regards to neat blend foam, the onset thermal degradation increased with the addition of CN particles, which also increased the thermal stability at 50% weight loss. Furthermore, CN acted as a reinforcing agent in improving the stiffness of the prepared blend foam. Overall, completely environmentally friendly foams were successfully prepared, as a potential material that can replace the current existing foam materials that pose many environmental concerns. However, there is a need to develop an environmentally friendly processing technique.


2019 ◽  
Vol 73 (12) ◽  
pp. 1403-1408 ◽  
Author(s):  
Mario E. Fajardo

We report updated infrared (IR) absorption measurements on vapor-deposited cryogenic parahydrogen (pH2) solids that indicate a ≈10% systematic error in our previous approach for determining a pH2 solid's thickness (S. Tam and M.E. Fajardo. Appl. Spectrosc. 2001. 55(12): 1634-1644). We provide corrected values for the integrated absorption intensities of the Q1(0)+S0(0) and S1(0)+S0(0) bands calculated over the 4495–4520 cm−1 and 4825–4855 cm−1 regions, respectively. New polarized IR absorption spectroscopy data demonstrate the insensitivity to polarization effects of the peak intensity of the QR(0) phonon sideband near 4228 cm−1. This feature provides an even quicker way for determining the thickness of a pH2 solid than via the integrated absorptions.


1987 ◽  
Vol 252 (2) ◽  
pp. G237-G243
Author(s):  
R. E. Bailey ◽  
R. A. Levine ◽  
J. Nandi ◽  
E. H. Schwartzel ◽  
D. H. Beach ◽  
...  

The lipid profile of isolated gastric superficial epithelial cells (SEC) was evaluated by proton nuclear magnetic resonance spectroscopy (1H-NMR). The most conspicuous resonance band in SEC spectra was due to the protons of +N(CH3)3 groups of phosphatidylcholine and, to a lesser degree, other phospholipid derivatives, on the basis of their chemical shift and addition of purified phospholipids. NMR of cell lysates and phospholipid extracts of SEC in deutero-chloroform provided further spectral resolution of these components. Phospholipase or ethanol treatments of SEC produced membrane disorganization reflected as increased peak intensity of the phospholipid signals. In addition, ethanol, in a dose-dependent manner, attenuated paranitrophenyl phosphatase activity, which correlated with inhibition of total and ouabain-sensitive 86Rubidium chloride uptake by SEC. This study suggests that NMR used in conjunction with other biochemical techniques can monitor SEC membrane structure-function relationships. NMR is a potentially powerful noninvasive probe to show changes in lipid membrane organization induced by low concentrations of ethanol (1%) and may indicate an early sign of "cytotoxicity" in intact SEC.


1982 ◽  
Vol 36 (4) ◽  
pp. 424-427 ◽  
Author(s):  
A. K. Arora ◽  
V. Umadevi

The effect of spectrometer resolution on the peak intensity and the full width at half maximum (FWHM) of a Lorentzian spectrum is obtained by evaluating the convoluted line shapes. Spectrometer resolution functions (SRF) having Gaussian and triangular profiles are considered separately. Empirical relations to estimate the true peak intensity and the FWHM from the observed parameters are suggested. These relations are valid over an extended range of parameters with an accuracy better than that of other methods suggested earlier. As an application, the true FWHM's and peak intensities of the main component of the Raman active Ag mode of sulphate ion in potash alum at low temperatures are evaluated.


NeuroImage ◽  
1996 ◽  
Vol 3 (3) ◽  
pp. S254
Author(s):  
J-B. Poline ◽  
K.J. Worsley ◽  
A.C. Evans ◽  
K.J. Friston

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