scholarly journals Characterization of Nile Red as a Tracer for Laser-Induced Fluorescence Spectroscopy of Gasoline and Kerosene and Their Mixture with Biofuels

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2822 ◽  
Author(s):  
Matthias Koegl ◽  
Christopher Mull ◽  
Kevin Baderschneider ◽  
Jan Wislicenus ◽  
Stefan Will ◽  
...  
Keyword(s):  
Nile Red ◽  
Mie Scattering ◽  
Spectral Shift ◽  
Laser Induced Fluorescence ◽  
Fluorescence Signal ◽  
Spectral Absorption ◽  
Absorption And Emission ◽  
Ethanol Blends ◽  
Increasing Temperature

Suitable fluorescence tracers (“dyes”) are needed for the planar measurement of droplet sizes by using a combination of laser-induced fluorescence (LIF) and Mie scattering. Currently, no suitable tracers have been characterized for application in planar droplet sizing in gasoline and kerosene fuels, as well as biofuel blends. One promising tracer is nile red, which belongs to the fluorophore group. For its utilization for droplet size measurements, preliminary characterization of the fluorescence of the respective fuel tracer mixtures are mandatory. For this purpose, the fluorescence and absorption behavior of nile red dissolved in the surrogate fuels Toliso and Jet A-1 as well as in biofuel blends was investigated. The fluorescence signal for nile red that was dissolved in the two base fuels Toliso and Jet A-1 showed a linear behavior as a function of dye concentration. The temperature effect on spectral absorption and emission of nile red was investigated in a specially designed test cell. An ethanol admixture to Toliso led to a spectral shift towards higher wavelengths. The absorption and emission bands were shifted towards lower wavelengths with increasing temperature for all fuels. Both absorption and fluorescence decreased with increasing temperature for all fuels, except for E20, which showed an increased fluorescence signal with increasing temperature. Jet A-1 and its blends with hydroprocessed esters and fatty acids (HEFA) and farnesane did not exhibit explicit variations in spectral absorption or emission, but these blends showed a more distinct temperature dependence compared to the Toliso-ethanol-blends. The effect of photo-dissociation of the LIF signal of the fuel tracer mixtures was studied, and all fuel mixtures besides Toliso showed a more or less distinct decay in the fluorescence signal with time. In summary, all investigated fuel-tracer mixtures are suitable for LIF/Mie ratio droplet sizing in combination with nile red at moderate temperatures and low evaporation cooling rates.

scholarly journals Fluorescence Spectroscopy for Studying Evaporating Droplets Using the Dye Eosin-Y

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 5985
Author(s):  
Matthias Koegl ◽  
Christoph Weiß ◽  
Lars Zigan
Keyword(s):  
Mie Scattering ◽  
Droplet Evaporation ◽  
Experimental Investigations ◽  
Fluorescence Signal ◽  
Eosin Y ◽  
Droplet Deformation ◽  
Two Phase ◽  
Lif Spectroscopy ◽  
Single Droplets

Laser-induced fluorescence (LIF) spectroscopy using dyes is frequently applied for characterization of liquids and two-phase flows. The technique is utilized e.g., for mixing studies, thermometry, or droplet sizing. One major application of the LIF technique combined with Mie-scattering is the planar measurement of droplet sizes in spray systems. However, its uncertainty is determined, among others, by varying dye concentration and temperature changes occurring during mixing and droplet evaporation. Systematic experimental investigations are necessary to determine the influence of dye enrichment effects on the LIF-signal of single droplets. For these investigations, the fluorescence dye Eosin-Y is dissolved in water and ethanol, which are typical solvents and working fluids in bio-medical applications and power engineering. A photo-physical characterization of the mixtures under various conditions was conducted using a spectrometric LIF setup and a micro cell. For ethanol, a small temperature dependency of the Eosin-Y LIF signal is observed up to 373 K. Photo-dissociation of Eosin-Y is negligible for solution in ethanol while it is distinct in water. The LIF signals of the single droplets are studied with an acoustic levitator. Effects of droplet evaporation, droplet deformation and varying dye concentration on the LIF-signal are studied. The single droplet measurements revealed a complex change of the fluorescence signal with reduced droplet size. This is due to droplet deformations leading to variations in the internal illumination field as well as dye enrichment during evaporation.

scholarly journals A Novel Approach for Measurement of Composition and Temperature of N-Decane/Butanol Blends Using Two-Color Laser-Induced Fluorescence of Nile Red

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5721
Author(s):  
Matthias Koegl ◽  
Mohammad Pahlevani ◽  
Lars Zigan
Keyword(s):  
Nile Red ◽  
Spectral Shift ◽  
Laser Induced Fluorescence ◽  
Temperature Changes ◽  
Novel Approach ◽  
Detection Approach ◽  
Wide Range ◽  
Fuel Mixtures ◽  
Butanol Concentration

In this work, the possibility of using a two-color LIF (laser-induced fluorescence) approach for fuel composition and temperature measurements using nile red dissolved in n-decane/butanol blends is investigated. The studies were conducted in a specially designed micro cell enabling the detection of the spectral LIF intensities over a wide range of temperatures (283–423 K) and butanol concentrations (0–100 vol.%) in mixtures with n-decane. Furthermore, absorption spectra were analyzed for these fuel mixtures. At constant temperature, the absorption and LIF signals exhibit a large spectral shift toward higher wavelengths with increasing butanol concentration. Based on this fact, a two-color detection approach is proposed that enables the determination of the butanol concentration. This is reasonable when temperature changes and evaporation effects accompanied with dye enrichment can be neglected. For n-decane, no spectral shift and broadening of the spectrum are observed for various temperatures. However, for butanol admixture, two-color thermometry is possible as long as the dye and butanol concentrations are kept constant. For example, the LIF spectrum shows a distinct broadening for B20 (i.e., 80 vol.% n-decane, 20 vol.% butanol) and a shift of the peak toward lower wavelengths of about 40 nm for temperature variations of 140 K.

Proton NMR characterization of gasoline–ethanol blends

Fuel ◽  
2014 ◽  
Vol 137 ◽  
pp. 335-338 ◽  
Author(s):  
A. Turanov ◽  
A.K. Khitrin
Keyword(s):  
Proton Nmr ◽  
Nmr Characterization ◽  
Ethanol Blends

Synthesis and Characterization of a Novel Linear Benzoxazine-Containing Polytriazole via Metal-Free Click Reaction and its Self-Crosslinking Behavior

2012 ◽  
Vol 557-559 ◽  
pp. 973-978
Author(s):  
Zhong Yi Xu ◽  
Lei Du ◽  
Li Qiang Wan ◽  
Fa Rong Huang
Keyword(s):  
Click Reaction ◽  
Decomposition Temperature ◽  
Linear Polymer ◽  
The Novel ◽  
Metal Free ◽  
Crosslinked Polymer ◽  
Degradation Behaviors ◽  
Ft Ir ◽  
Increasing Temperature

A novel linear benzoxazine-containing polytriazole was successfully synthesized via metal-free click reaction. Benefited from the advantages of click reaction, the synthesis procedure was easily and efficiently. The linear polymer could be transformed into crosslinked structure after ring-opening polymerization of oxazine induced by the increasing temperature. The FT-IR characterization verified the structure transformation between linear and crosslinked polymer. Moreover, the thermal properties and thermal degradation behaviors of linear polymer and the corresponding crosslinked polymer were studied by DSC and TGA. The novel polytriazole was proved to be a kind of thermal stable polymers with high thermal decomposition temperature (Td5over 300°C).

The High Temperature Deformation Behavior of A Cr2Nb Ordered Intermetallic System

1990 ◽  
Vol 213 ◽  
Author(s):  
G. E. Vignoul ◽  
J.M. Sanchez ◽  
J. K. Tien
Keyword(s):  
Deformation Behavior ◽  
Elevated Temperatures ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Deformation Law ◽  
Ordered Intermetallic ◽  
Intermetallic System ◽  
Increasing Temperature ◽  
Stress Term

ABSTRACTA basic characterization of the deformation behavior of Cr2Nb by microindention at ambient and elevated temperatures (up to 1400 °C) was undertaken. The microhardness of this system was seen to decrease with increasing temperature, from 1040 MPa at 25°C to 322 MPa at 1400 °C. Further, the microindention creep behavior of this system was studied by varying time on load at T = 1000 and 1200°C. Analysis of the data showed that m = 24 and Qapp = 477.61 kJ/mole. These unusually high values are indicative of the existence of an effective resisting stress against creep. When the data was fit against a microindention creep deformation law which was modified to incorporate an effective resisting stress term, it was determined that m = 4.5, Qcreep = 357 kJ/mole and the resisting stress term σr = 300 MPa.

Characterization of Ethanol Blends Combustion Processes and Soot Formation in a GDI Optical Engine

2013 ◽  
Author(s):  
Francesco Catapano ◽  
Silvana Di Iorio ◽  
Maurizio Lazzaro ◽  
Paolo Sementa ◽  
Bianca Maria Vaglieco
Keyword(s):  
Soot Formation ◽  
Optical Engine ◽  
Ethanol Blends ◽  
Combustion Processes

scholarly journals Improved Procedure for Natural Convection Garlic Drying

2020 ◽  
Vol 23 (2) ◽  
pp. 92-98
Author(s):  
Amor Bouhdjar ◽  
Hakim Semai ◽  
Amal Boukadoum ◽  
Sofiane Elmokretar ◽  
Azzedine Mazari ◽  
...  
Keyword(s):  
Effective Diffusivity ◽  
Diffusivity Coefficient ◽  
Solar Drying ◽  
Residual Moisture ◽  
Drying Temperature ◽  
Solar Systems ◽  
Energy Consuming ◽  
C 50 ◽  
Increasing Temperature

AbstractVegetable drying is an energy consuming procedure despite the fact that it is the most efficient way to preserve agricultural products. This study investigates a new way to dry good quality garlic at lower cost. Thin garlic layer was submitted to free convection airflow at air drying temperature of 40 °C, 50 °C, and 60 °C. Using the slope method, effective diffusivity coefficient was determined at each drying temperature during the first and second falling drying rate periods. Considering the former, it increased with increasing temperature. In relation to latter, it decreased with the temperature increase. However, at low drying temperatures, process keeps on going to very low moisture content; and it develops to an asymptotic value at high temperatures, indicating that shrinking at high temperature prevents evaporation of some residual moisture. Considered separately, these temperatures do not reflect the conditions met in solar drying, since in solar systems, air temperature increases during the day with increasing solar radiation. Therefore, characterization of garlic drying by means of step temperature varying – the first hour of drying at 40 °C; the second hour of drying at 50 °C, and the remaining time of drying at 60 °C – might better correspond with conditions under solar drying and result in better understanding of the process.

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