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Octane prediction from infrared spectroscopic data
摘要： A model for the prediction of research octane number (RON) and motor octane number (MON) of hydrocarbon mixtures and gasoline-ethanol blends has been developed based on infrared spectroscopy data of pure components. Infrared spectra for 61 neat hydrocarbon species were used to generate spectra of 148 hydrocarbon blends by averaging the spectra of their pure components on a molar basis. The spectra of 38 FACE (Fuels for Advanced Combustion Engines) gasoline blends were calculated using PIONA (Paraffin, Isoparaffin, Olefin, Naphthene, and Aromatic) class averages of the pure components. The study sheds light on the significance of dimensional reduction of spectra and shows how it can be used to extract scores with linear correlations to the following important features: molecular weight, paraffinic CH3 groups, paraffinic CH2 groups, paraffinic CH groups, olefinic -CH=CH2 groups, naphthenic CH-CH2 groups, aromatic C-CH groups, ethanolic OH groups, and branching index. Both scores and features can be used as input to predict octane numbers through nonlinear regression. Artificial Neural Network (ANN) was found to be the optimal method where the mean absolute error on a randomly selected test set was within the experimental uncertainty of RON, MON, and octane sensitivity.
关键词： octane prediction,infrared spectroscopy,hydrocarbon blends,artificial neural network,gasoline-ethanol blends,dimensional reduction
更新于2025-09-19 17:13:59
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Thermodynamics of Natural Pigment-Doped Ethanol under Monochromatic Laser Irradiation
摘要： A laser beam heats a mixture of ethanol and anthocyanins producing the effect of a reciprocating machine. This behaviour is analyzed in terms of the stable, metastable and unstable states of Landau and Lifschitz. Trying first with the van der Waals equation of state, with negative results because the system state is normally far from the critical state, a modified version, with van der Waals coefficients depending linearly on the temperature is proposed, based in the thermodynamic properties of ethanol at room and critical temperatures. The resulting theory allows us to understand the discontinuous results concerning the absorption of the laser beam in terms of a thermodynamic cycle and its frequency dependence on the laser light focus position. Slight changes in the experimental setup may enable the measurement of thermodynamic properties in metastable states.
关键词： Ethanol,van der Waals Equation,Laser Irradiation,Thermodynamics,Natural Pigments
更新于2025-09-16 10:30:52
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Enhanced metal assisted etching method for high aspect ratio microstructures: Applications in silicon micropillar array solar cells
摘要： A solar cell device, fabricated on high density array cylindrical pillars, enables photogenerated carrier collection in the radial direction, thus shortening the path length of the carriers reaching the junction. It also provides advantages over conventional planar junction solar cells, such as reduced surface re?ectance and enhanced light trapping. In this study, highly ordered Si micropillars were fabricated by photolithography and metal assisted etching (MAE) methods. It is shown that the use of ethanol as a solvent during the etching process and increasing HF concentration in the MAE solution both improve the quality of the surfaces of the pillars. Micropillars with smooth sidewalls and a high aspect ratio were obtained in this way. Solar cells with a radial junction were then fabricated on these micropillars. Standard doping, SiO2/SiNx passivation, and metallisation steps were carried out for the fabrication of solar cells with di?erent micropillar lengths. A signi?cant decrease in re?ectance values was observed as the micropillar length increased, as expected. Solar cell short circuit current density (Jsc) and e?ciency (η) of the solar cells tended to increase with micropillar length up to 11.5 μm and then decrease due to increased surface recombination. The maximum e?ciency achieved in this study is 17.26%.
关键词： Solar cell,Ethanol,Micropillar,Metal assisted etching,High aspect ratio,Radial junction
更新于2025-09-16 10:30:52
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Synthesis of colloidal aluminum nanoparticles by nanosecond pulsed laser and the effect of external electric field and laser fluence on ablation rate
摘要： In this paper, the ablation of aluminum was induced by a Q-switched Nd:YAG laser (1064 nm, ~10 ns and 10 Hz) in ethanol at room temperature for producing colloidal nanoparticles. Two different experimental schemes (i.e. the electric field parallel, and perpendicular to the laser propagation path) were used to investigate the dependence of ablation rate on the external electric field characteristics and the laser fluence. The results show that at a constant laser fluence, regardless of the type of scheme, the ablation rate is increased in the presence of electric field. However, the characteristics of craters strongly depend on the direction of the electric field. The results also show that at both schemes with a constant electric field, the ablation rate rises when the laser fluence is increased. According to the results, it can be concluded that the ablation rate enhanced by applying electric field and increasing laser pulse energy.
关键词： Ablation rate,Laser materials processing,Laser ablation efficiency,Electric field,Ethanol interaction ambient
更新于2025-09-16 10:30:52
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Fabrication of Polypropylene Nanofibers from Polypropylene/Polyvinyl Butyral Blend Films Using Laser‐Assisted Melt‐Electrospinning
摘要： Polypropylene (PP) nano?bers, a few hundred nanometers in diameter, are of immense importance in the ?ber industry. This article reports the fabrication of delicate PP nano?bers. Polyvinyl butyral (PVB) was added to PP as a blend component, and a nozzle-free melt-electrospinning system with a line-like CO2 laser melting device was used to manufacture PP nano?bers. We investigated the effect of PVB ratio on ?ber diameter. The addition of PVB was found to be potentially very bene?cial in PP/PVB blends, resulting in improved PP crystallinity and a steady decrease of ?ber diameter with high productivity. The reduction of ?ber diameter was attributed to the decline of viscosity, increase of surface adhesion properties, and polarity of blends due to the inclusion of PVB. To produce PP nano?ber, the PVB was removed from PP/PVB blend ?bers with an ethanol treatment. A drastic drop of PP ?ber diameter followed by ?ber splitting was observed after PVB removal. We obtained PP nano?bers with a diameter as low as 181 (cid:1) 105 nm from the blend ?ber with 90% PVB. Infrared spectroscopy of ?bers demonstrated that PP ?bers from pure polymer and blends showed the same characteristic peaks.
关键词： Polyvinyl butyral,ethanol treatment,Polypropylene,melt-electrospinning,CO2 laser,nano?bers
更新于2025-09-12 10:27:22
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Low Energy Pulsed Laser Excitation in UV Enhances the Gas Sensing Capacity of Photoluminescent ZnO Nanohybrids
摘要： Nanohybrids, composed of luminescent zinc oxide (ZnO) nanoparticles dispersed in an inert polydimethylsiloxane (PDMS) matrix, exhibit an excellent ability to follow changes in the type and composition of their surrounding atmosphere. These changes are found to affect the UV photoluminescence (PL) emission of the ZnO-PDMS hybrids measured at room temperature. The influence of irradiation parameters, such as excitation intensity and wavelength, on the response of the ZnO-PDMS sensor against ethanol and oxygen, have been systematically investigated in a comparative study performed employing pulsed excitation at 248 and 355 nm. This study represents the first demonstration that the sensing performance of the PL-based ZnO sensors can be optimized by tuning the excitation parameters and it particularly illustrates that maintaining a low pump energy density is crucial for enhancing the sensitivity of the sensor achieving response values approaching 100%.
关键词： ZnO photoluminescence,ethanol sensing,optical sensor,ZnO nanoparticles,gas sensing,oxygen sensing,ZnO-PDMS nanocomposite
更新于2025-09-12 10:27:22
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Ethanol-Precipitation-Assisted Highly Efficient Synthesis of Nitrogen-Doped Carbon Quantum Dots from Chitosan
摘要： Nitrogen-doped carbon quantum dots (NCQDs) were prepared from chitosan through a hydrothermal reaction. When ethanol precipitation was used as the puri?cation method, a high product yield of 85.3% was obtained. A strong blue ?uorescence emission with a high quantum yield (QY) of 6.6% was observed from the NCQD aqueous solution. Physical and chemical characteristics of the NCQDs were carefully investigated by transmission electron microscopy (TEM), X-ray di?raction (XRD), Fourier transform infrared spectra (FTIR), Raman spectra, X-ray photoelectron spectroscopy (XPS), and transient ?uorescence spectra. Experimental results showed that diameters of the NCQDs were in the range of 2?10 nm. The carbon quantum dots possess good water dispersibility and precipitation by ethanol. When used for metal ion detection, the detection limit of the NCQDs for Fe3+ was as low as 1.57 μM. This work proposed a facile method to synthesize NCQDs from chitosan with high yield and demonstrated that carbon quantum dots derived from chitosan were promising for ion detection.
关键词： ethanol precipitation,metal ion detection,chitosan,hydrothermal reaction,Nitrogen-doped carbon quantum dots
更新于2025-09-12 10:27:22
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Large-Range, Highly-Sensitive, and Fast-Responsive Optical Fiber Temperature Sensor Based on the Sealed Ethanol in Liquid State Up to its Supercritical Temperature
摘要： A highly-sensitive and fast-responsive optical ?ber temperature sensor based on the sealed liquid ethanol with a large detection range was proposed. The ethanol was injected into the ?ber Fabry-Perot (FP) micro-cavity through the thin core silica capillary tube (SCT), which was then spliced to a section of singe mode ?ber. A section of air core was formed in the thin core SCT near the splicing position. If the volume of the sealed ethanol is much larger than that of the air core, the ethanol can remain liquid state until its supercritical temperature (about 243 °C) at which the ethanol becomes supercritical state. The temperature sensitivity of proposed sensor with a volume ratio 2.89 of ethanol to air reaches –497.6 pm/ °C with an upper detection limit of 220 °C. Meanwhile, the order of the interference fringe can be distinguished by monitoring the transmission loss of the sensor, which can assist wavelength demodulation in the large detection range. Besides, the proposed ?ber temperature sensor is with the advantages of fast response (less than 1 s for the temperature variation of about 90 °C) and good repeatability.
关键词： liquid ethanol,interferometry,Optical ?ber sensor,temperature
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Localized Surface Plasmon Resonance Based Tapered Fiber Optic Ethanol Sensor
摘要： Ethanol is mostly found in drinks, food, beverages and in the human body fluids, e.g. urine, serum, sweat, saliva, and blood etc. A high concentration of ethanol in body fluids causes various metabolic disorders like diabetes, cirrhosis and hepatitis. Therefore, the detection of ethanol is essential for clinical and forensic investigation. In this study, we report the fabrication and characterization of a localized surface plasmon resonance (LSPR) based tapered fiber optic ethanol sensor. Nowadays LSPR is a very useful technique for biosensing applications. For the LSPR phenomenon, the size of the nanoparticles should be smaller than the wavelength of the light. When an electromagnetic wave is incident on metal nanoparticles, the collective oscillation of the free electrons inside the metal nanoparticles occurs. The maximum amplitude occurs when the frequency of oscillation matches with the frequency of the incident light. Due to the frequency matching a strong field enhancement is observed around the nanoparticles. In the phenomenon called as LSPR, the peak absorbance wavelength depends on the dielectric constant of the medium surrounding the nanoparticles. To fabricate the LSPR based fiber optic probe for ethanol sensing, we have synthesized gold nanoparticles (AuNP) using Turkevich method. The TEM image of AuNPs is shown in fig. 1 (a). The schematic of the LSPR probe is shown in fig 1 (b). The probe is consists of AuNPs over the core of the tapered optical fiber followed by the immobilized layer of enzyme alcohol dehydrogenase (ADH) and coenzyme nicotinamide adenine dinucleotide (NAD). For the attachment of gold nanoparticles the core was cleaned by pirhana solution and kept in amino silane solution. Dip coating was used to coat the AuNPs over the silanized core. After this, the probe was incubated in 1 mM aqueous solution of cystamine dihydrochloride for 1 h for attachment of –NH2 groups over the AuNPs-coated fiber core. Finally, the probe was incubated for 12 h into the ADH and NAD solution. This completed the probe fabrication step.
关键词： Ethanol Sensor,Alcohol Dehydrogenase,Tapered Fiber Optic,Localized Surface Plasmon Resonance,Nicotinamide Adenine Dinucleotide,Gold Nanoparticles
更新于2025-09-11 14:15:04
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Metal–Organic Framework-Assisted Construction of TiO <sub/>2</sub> /Co <sub/>3</sub> O <sub/>4</sub> Highly Ordered Necklace-like Heterostructures for Enhanced Ethanol Vapor Sensing Performance
摘要： In this work, we report a metal-organic frameworks (MOFs)-assisted strategy to synthesize necklace-like TiO2/Co3O4 nanofibers with highly ordered heterostructures via a facile approach including electrospinning and subsequent calcination. Polycrystalline TiO2 nanofiber and Co3O4 nanocage are consummate interconnected to form highly ordered heterogeneous nanostructure, which can be benefit for precisely accommodating the interface resistance of the p-n heterojunctions and future realization of improved materials performance. The ethanol gas-sensing investigation showed that TiO2/Co3O4 nanofibers sensors exhibited high ethanol response (Rair/Rgas -1 = 16.7 @ 150 ppm) and low operating temperature of 150 °C. The sensing enhancement mechanism of the TiO2/Co3O4 nanofibers is related to the formation of heterojunction at interfaces and the high catalytic activity of MOF-derived Co3O4. Furthermore, this versatile method is a promising approach to construct ordered heterostructures and extend the MOF-based heterogeneous materials toward wide applications.
关键词： Ordered Heterostructures,MOF-assisted,Ethanol vapor detect,Heterogeneous Nanofiber,Gas sensor
更新于2025-09-10 09:29:36