Light-scattering, Raman spectra and allied physical properties of some essential and vegetable oils

1937 ◽  
Vol 5 (5) ◽  
pp. 385-406 ◽  
Author(s):  
C. Dakshinamurti
Keyword(s):  
Light Scattering ◽  
Physical Properties ◽  
Raman Spectra ◽  
Vegetable Oils

scholarly journals Optical and physical properties of aerosols in the boundary layer and free troposphere over the Amazon Basin during the biomass burning season

2006 ◽  
Vol 6 (10) ◽  
pp. 2911-2925 ◽  
Author(s):  
D. Chand ◽  
P. Guyon ◽  
P. Artaxo ◽  
O. Schmid ◽  
G. P. Frank ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Light Scattering ◽  
Physical Properties ◽  
Biomass Burning ◽  
Large Scale ◽  
Amazon Basin ◽  
Single Scattering ◽  
Free Troposphere ◽  
Wet Season ◽  
Average Mass

Abstract. As part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC) campaign, detailed surface and airborne aerosol measurements were performed over the Amazon Basin during the dry to wet season from 16 September to 14 November 2002. Optical and physical properties of aerosols at the surface, and in the boundary layer (BL) and free troposphere (FT) during the dry season are discussed in this article. Carbon monoxide (CO) is used as a tracer for biomass burning emissions. At the surface, good correlation among the light scattering coefficient (σs at 545 nm), PM2.5, and CO indicates that biomass burning is the main source of aerosols. Accumulation of haze during some of the large-scale biomass burning events led to high PM2.5 (225 μg m−3), σs (1435 Mm−1), aerosol optical depth at 500 nm (3.0), and CO (3000 ppb). A few rainy episodes reduced the PM2.5, number concentration (CN) and CO concentration by two orders of magnitude. The correlation analysis between σs and aerosol optical thickness shows that most of the optically active aerosols are confined to a layer with a scale height of 1617 m during the burning season. This is confirmed by aircraft profiles. The average mass scattering and absorption efficiencies (545 nm) for small particles (diameter Dp<1.5 μm) at surface level are found to be 5.0 and 0.33 m2 g−1, respectively, when relating the aerosol optical properties to PM2.5 aerosols. The observed mean single scattering albedo (ωo at 545 nm) for submicron aerosols at the surface is 0.92±0.02. The light scattering by particles (Δσs/Δ CN) increase 2–10 times from the surface to the FT, most probably due to the combined affects of coagulation and condensation.

Decomposition of Mixed Phase Silicon Raman Spectra

2009 ◽  
Vol 1153 ◽  
Author(s):  
Martin Ledinský ◽  
Jiri Stuchlík ◽  
Aliaksei Vetushka ◽  
Antonin Fejfar ◽  
Jan Kočka
Keyword(s):  
Thin Film ◽  
Factor Analysis ◽  
Light Scattering ◽  
Raman Spectra ◽  
Absolute Intensity ◽  
Mixed Phase ◽  
Excitation Wavelength ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film ◽  
Spectral Components

AbstractSeries of Raman spectra were measured for microcrystalline silicon thin film with variable crystallinity. Five sets of Raman spectra (corresponding to excitations at 325 nm, 442 nm, 514.5 nm, 632.8 nm and 785 nm wavelengths) were subjected to factor analysis which showed that each set of spectra consisted of just two independent spectral components. Decomposition of the measured Raman spectra into the amorphous and the microcrystalline components is illustrated for 514.5 nm and 632.8 nm excitations. Effect of the light scattering on absolute intensity of Raman spectra was identified even for excitation wavelength highly absorbed in the mixed phase silicon layers.

Raman spectroscopy as a versatile tool for studying of explicit contribution of anharmonicity

2014 ◽  
Vol 23 (04) ◽  
pp. 1450051 ◽  
Author(s):  
M. R. Joya ◽  
J. D. Gonzalez ◽  
J. Barba-Ortega
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Expansion ◽  
Physical Properties ◽  
Raman Spectra ◽  
Lead Titanate ◽  
Ferroelectric Ceramics ◽  
Effect Of Temperature ◽  
Grüneisen Parameter ◽  
Versatile Tool ◽  
Temperature And Pressure

The Raman spectroscopy can be used as a didactic technique in the study of the thermal expansion of Grüneisen parameter and anharmonic behavior of materials. Here, we present exemplary, the lead titanate doped with lanthanum (PLT). However, this method can be used to study various materials. The ferroelectric ceramics have been one of the most studied compounds in the literature both in obtaining the same, as in behavior of chemical and physical properties. The structural PbTiO 3 phase may change either by the application of pressure, temperature or concentration, thereby allowing a study of behavior anharmonic of the material [M. R. Joya, J. Barba and P. S. Pizani, J. Appl. Phys.113 (2013) 013512]. This paper gives a brief review of the effect of temperature and pressure on Raman spectra.

scholarly journals Selected Physical Properties Assessment of Sunflower and Olive Oils

2019 ◽  
Vol 22 (3) ◽  
pp. 86-91
Author(s):  
Peter Hlaváč ◽  
Monika Božiková ◽  
Ana Petrović
Keyword(s):  
Physical Properties ◽  
Vegetable Oils ◽  
Dynamic Viscosity ◽  
Kinematic Viscosity ◽  
Rheological Parameters ◽  
Measured Temperature ◽  
Oil Viscosity ◽  
Temperature Range ◽  
Olive Oils ◽  
Two Samples

Abstract Presented paper is focused on comparison of certain physical properties of selected vegetable oils. Physical properties, such as density, dynamic, kinematic viscosity and fluidity, were experimentally determined. All experiments were conducted on two samples of vegetable oils: sunflower and extra virgin olive oils with approximate temperature range of 5–32 °C. Density of oils was determined by oscillation method utilizing digital densimeter Anton Paar DMA 4500M at different temperatures. Dynamic viscosity was measured by means of rotational viscometer Anton Paar DV-3P. The rest of rheological parameters were determined on the basis of their definitions. Obtained results are depicted as graphical dependencies of rheological parameters and density on temperature. These dependencies of vegetable oils on dynamic and kinematic viscosity showed decreasing exponential shape, which is in compliance with Arrhenius equation; temperature dependencies on fluidity showed an increasing exponential shape for both samples. Density dependencies of samples on temperature were characteristic with decreasing linear function within measured temperature range. Similar results were achieved by other researchers. On the basis of measured values, it is evident that dynamic viscosity of extra virgin olive oil shows higher values than sunflower oil viscosity, which is a result of different composition of oils.

scholarly journals Light Scattering as a Clue to Cometary Dust Structure

2005 ◽  
Vol 13 ◽  
pp. 498-500 ◽  
Author(s):  
A. Chantal Levasseur-Regourd ◽  
E. Hadamcik ◽  
J. Lasue
Keyword(s):  
Light Scattering ◽  
Physical Properties ◽  
Phase Angle ◽  
Linear Polarization ◽  
Dust Structure ◽  
Cometary Dust ◽  
Microgravity Conditions

AbstractThe linear polarization of comets depends upon the cometary dust physical properties, as well as upon the phase angle and the wavelength. The observed similarities and discrepancies provide drastic constraints on the physical properties of the dust. A series of measurements of light scattering properties on clouds of particles and of the aggregates they form under microgravity conditions should allow the interpretation of the observations in terms of physical properties of the dust.

Heterogeneous Microcomposite Materials Based on Porous Matrices and Liquid Crystals

1996 ◽  
Vol 431 ◽  
Author(s):  
F. M. Aliev ◽  
G. P. Sinha
Keyword(s):  
Liquid Crystals ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Physical Properties ◽  
Wide Spectrum ◽  
Relaxation Times ◽  
Average Pore ◽  
Relaxational Process ◽  
Porous Matrices ◽  
Interconnected Pores

AbstractHeterogeneous microcomposite materials based on porous matrices with randomly oriented, interconnected pores (porous glasses with average pore sizes of 100 Å and 1000 Å) and parallel cylindrical pores (Anopore membranes with pore diameters of 200 Å and 2000 Å) impregnated with liquid crystals (LC) were investigated by dynamic light scattering and dielectric spectroscopy. The physical properties of confined LC are very different from that of the bulk. One of the new properties among others observed for LC confined in porous matrices is the slow relaxational process which does not exist in the bulk LC and a wide spectrum of relaxation times (10−8 – 10)s which were established in both dynamic light scattering and dielectric experiments. We found that for LC dispersed in porous matrices with randomly distributed interconnected pores, the contribution to physical properties and observed behavior from interfacial layers dominates and almost completely determines low frequency relaxational process.

COMPARATIVE STUDIES ON PHYSICAL PROPERTIES OF VEGETABLE OILS AND THEIR BLENDS AFTER FRYING

2002 ◽  
Vol 9 (4) ◽  
pp. 259-276 ◽  
Author(s):  
N. S. SUSHEELAMMA ◽  
M. R. ASHA ◽  
R. RAVI ◽  
A. K. VASANTH KUMAR
Keyword(s):  
Physical Properties ◽  
Vegetable Oils ◽  
Comparative Studies

Screening the physical properties of novel Pseudomonas exopolysaccharides by HPSEC with multi-angle light scattering and viscosity detection

1997 ◽  
Vol 32 (3-4) ◽  
pp. 213-221 ◽  
Author(s):  
Marshall L. Fishman ◽  
Paola Cescutti ◽  
William F. Fett ◽  
Stanley F. Osman ◽  
Peter D. Hoagland ◽  
...  
Keyword(s):  
Light Scattering ◽  
Physical Properties
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