scholarly journals Optical Properties of Polyvinyl Alcohol Films Modified with Silver Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Vladimir Agabekov ◽  
Nadezhda Ivanova ◽  
Viacheslav Dlugunovich ◽  
Igor Vostchula
Keyword(s):  
Optical Properties ◽  
Polyvinyl Alcohol ◽  
Uv Light ◽  
Incident Radiation ◽  
Light Passing ◽  
Axial Tension ◽  
Linearly Polarized ◽  
Phase Plates ◽  
Elliptically Polarized ◽  
Polyvinyl Alcohol Films

Polyvinyl alcohol (PVA) films modified with Ag nanoparticles and orientated by single-axial tension do not possess dichroism at light passing as well as the film that is cross-linked under the action of bichromates and UV light. These films are double-ray refracting and behave themselves as phase plates that transform linearly polarized incident radiation to elliptically polarized one. The film of latter type has optical properties of reflective diffuse polarizer with polarizing ability ~0.8 in the range of observation angles from 20° to 80°.

Effect of concentration on optical properties of dyes incorporated into polyvinyl alcohol films

1986 ◽  
Vol 36 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Vladimir Z. Paschenko ◽  
Andrew N. Ponomaryev ◽  
Victor I. Yuzhakov
Keyword(s):  
Optical Properties ◽  
Polyvinyl Alcohol ◽  
Polyvinyl Alcohol Films

scholarly journals Optical properties of Polyvinyl Alcohol Films doped with Fe

2017 ◽  
Vol 4 (4) ◽  
pp. 1-7
Author(s):  
Mahmood Kareem ◽  
Sami Chiad ◽  
Nadir Habubi ◽  
Khalid Abass ◽  
Nidhal Jandow ◽  
...  
Keyword(s):  
Optical Properties ◽  
Polyvinyl Alcohol ◽  
Polyvinyl Alcohol Films

Hyperfine Polarization Structure of Jupiter’s Radio Bursts

1976 ◽  
Vol 3 (1) ◽  
pp. 49-51 ◽  
Author(s):  
P. S. Whitham
Keyword(s):  
Fine Structure ◽  
Radio Emission ◽  
Preliminary Report ◽  
Low Frequency ◽  
Incident Radiation ◽  
Radio Bursts ◽  
Polarization Structure ◽  
Yield Information ◽  
Linearly Polarized ◽  
Elliptically Polarized

Observations of Jupiter’s decametric radio burst have established that above 20 MHz more than 90% of the emission is elliptically polarized in the RH sense, but below this frequency the proportion of the LH polarization increases (Sherrill 1965) until at 10 MHz nearly 40% of the emission is LH polarized (Dowden 1963). The best time and frequency resolutions so far obtained when examining the polarization of the spectra of Jupiter’s bursts have been 10 ms and 50 kHz respectively (Gordon and Warwick 1967, Riihimaa 1975). To study the fine structure of Jupiter’s emission as observed by the linearly polarized Llanherne low frequency radio telescope (Ellis 1972), spectrum analysers with resolutions in the ranges 0.3 — 1 msec and 2–10 kHz have been used (Ellis 1973a, 1973b, 1974, 1975). A new telescope at Llanherne, which is capable of detecting the RH and LH circular components of incident radiation, is being used in conjunction with these analysers to yield information of the hyperfine polarization structure of Jupiter’s decametric radio emission. This paper is a preliminary report of this investigation.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

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