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Research Interests: Low Frequency, Magnetic field, Maize, Order, Electromagnetic Field, and 3 moreZea mays, ACTA, and Dry Weight
Basic data on thermal, structural and rheological properties of cooked maize tortillas were investigated, with the aim of understanding the role of the slaked lime [Ca(OH)2] that is incorporated during the alkaline cooking process. The... more
Basic data on thermal, structural and rheological properties of cooked maize tortillas were investigated, with the aim of understanding the role of the slaked lime [Ca(OH)2] that is incorporated during the alkaline cooking process. The changes in the thermal parameters, such as thermal conductivity, thermal diffusivity and specific heat, measured by photoacoustic techniques, as well as the changes in texture and X-ray patterns are presented as a function of the Ca(OH)2 concentration. The results show strong evidence that there is a threshold concentration of Ca(OH)2 of 0.25%, above and below which there are different behaviour patterns of the measured properties of the tortillas.
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Research Interests:
Research Interests: Engineering, Materials Engineering, Chemical Engineering, Condensed Matter Physics, Analytical Chemistry, and 35 moreBiomedical Engineering, Microstructure, Food Engineering, Composites, Materials, Scanning Electron Microscopy, Composite Materials, Lubrication, Tribology, Atomic Force Microscopy, Fouling, AFM, Nanofiltration, Solid waste, Physical sciences, Moisture, XRD, CHEMICAL SCIENCES, XPS, Titanium alloys, Microhardness, Cladding, Microstructures, Dendrite, Intermetallic Compounds, Food Sciences, Chrome, Fouling of Membrane, X Ray Photoelectron Spectroscopy, Journal of Applied Polymer Science, Tensile Strength, Water Vapor, Physical Properties, Laser Cladding, and Low molecular weight
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Ga1-yAs alloys grown by liquid phase epitaxy on GaAs substrates, by means of the open photoacoustic cell detection technique and the temperature-rise method under continuous light illumination. The values of the thermal conductivity,... more
Ga1-yAs alloys grown by liquid phase epitaxy on GaAs substrates, by means of the open photoacoustic cell detection technique and the temperature-rise method under continuous light illumination. The values of the thermal conductivity, diffusivity and specific heat were obtained in the 0yGa1-yAs band gap is mainly direct. The technique presented here is based upon an effective sample model which is shown to be suitable for the determination of the thermal properties of two layer semiconductor specimens.
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The correlation between the surface roughness and the surface recombination velocity in CdTe is explored. This is achieved through the use of atomic force microscopic analysis and the investigation of the photoacoustic signal as a... more
The correlation between the surface roughness and the surface recombination velocity in CdTe is explored. This is achieved through the use of atomic force microscopic analysis and the investigation of the photoacoustic signal as a function of the modulation frequency in a heat-transmission configuration. It is also shown that in the modulation frequency range where the samples are thermally thick, analyses of the photoacoustic signal amplitude and phase can single-out the different non-radiative recombination heat sources responsible for the signal, even in the case where the regimes are strongly mixed. The procedure employed in this investigation reveals as a very promising method in the field of characterization of surface finishes in semiconductors.
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Research Interests:
Research Interests:
Time resolved thermal lens (TL) spectrometry is applied to the study of the thermal diffusivity of edible oils such as olive, and refined and thermally treated avocado oils. A two laser mismatched-mode experimental configuration was used,... more
Time resolved thermal lens (TL) spectrometry is applied to the study of the thermal diffusivity of edible oils such as olive, and refined and thermally treated avocado oils. A two laser mismatched-mode experimental configuration was used, with a He–Ne laser as a probe beam and an Ar+ laser as the excitation one. The characteristic time constant of the transient thermal lens was obtained by fitting the experimental data to the theoretical expression for a transient thermal lens. The results showed that virgin olive oil has a higher thermal diffusivity than for refined and thermally treated avocado oils. This measured thermal property may contribute to a better understanding of the quality of edible oils, which is very important in the food industry. The thermal diffusivity results for virgin olive oil, obtained from this technique, agree with those reported in the literature.
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One of the most important factors in the preparation of edible films regards the choice of ingredients. Edible films are commonly prepared with single or mixed high-molecular-weight compounds like proteins and gums. In the present work,... more
One of the most important factors in the preparation of edible films regards the choice of ingredients. Edible films are commonly prepared with single or mixed high-molecular-weight compounds like proteins and gums. In the present work, protein and gum-based edible films were prepared and their thermal diffusivity determined by photoacoustics. The films were prepared with different concentrations of four basic ingredients: whey protein concentrate, mesquite gum, sodium alginate, and κ-carrageenan. In single-component films, the highest thermal diffusivity was found in mesquite gum (1.97×10−7m2ċs−1), followed by sodium alginate, whey protein concentrate, and κ-carrageenan samples. In composed films, the highest thermal diffusivity was obtained in a ternary film made of mesquite gum, whey protein concentrate, and sodium alginate in identical parts (5.20×10−7m2ċs−1).
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Photoacoustic spectroscopy (PAS) is widely used for diverse applications in different areas. These include studies in material, environmental, and life sciences. In the present work the study of pigments from pottery surfaces and volumes... more
Photoacoustic spectroscopy (PAS) is widely used for diverse applications in different areas. These include studies in material, environmental, and life sciences. In the present work the study of pigments from pottery surfaces and volumes of Mexican (Aztec) and Poblana cultures that were developed in central Mexico from 1325 to 1521 and 1521 to 1800, respectively, is reported. The optical absorption spectra from each archeological sample was obtained using PAS. The superficial spectra were also compared with standard color pigments and archeological registers. Complementary energy dispersive spectroscopy (EDS) analysis of these archeological potteries gave us their elemental composition which agreed with other studies about their composition and technology of the pottery manufacturing.
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Research Interests:
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In this work, the thermal effusivities of Pb0.88Ln0.08Ti0.98Mn0.02O3 (Ln=La, Eu) ferroelectric ceramics are studied since it can be use as pyroelectric detectors. Photothermal techniques were used to determine thermal effusivity. The... more
In this work, the thermal effusivities of Pb0.88Ln0.08Ti0.98Mn0.02O3 (Ln=La, Eu) ferroelectric ceramics are studied since it can be use as pyroelectric detectors. Photothermal techniques were used to determine thermal effusivity. The preparation of the ceramics was perform in our laboratory by using the oxide-mixing conventional method. It should be noticed that these ceramics were taken in an unpoled state. All
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The use of photothermal microscopy to obtain superficial and in-depth images, by means of the interaction of a thermal wave with the analyzed material, has reached great interest due to its numerous applications. The application of the... more
The use of photothermal microscopy to obtain superficial and in-depth images, by means of the interaction of a thermal wave with the analyzed material, has reached great interest due to its numerous applications. The application of the photopyroelectric microscopy technique to obtain images of plant leaves is presented in this article. In the experimental setup, a pyroelectric sensor and linear micro-positioners were used to obtain the photothermal signal at each point of the sample. Then it is possible to obtain images of plant leaves through their differences in local thermal properties and thickness.
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Research Interests:
Thermal diffusivities of the Pb0.88(Ln)0.08Ti0.98Mn0.02O3 (Ln = La, Eu) ferroelectric ceramic system are investigated by using Open Photoacoustic Cell (OPC) technique. The preparation of the ceramics was performed in our laboratory by... more
Thermal diffusivities of the Pb0.88(Ln)0.08Ti0.98Mn0.02O3 (Ln = La, Eu) ferroelectric ceramic system are investigated by using Open Photoacoustic Cell (OPC) technique. The preparation of the ceramics was performed in our laboratory by using the oxide-mixing conventional ceramic method. It should be noted that these ceramics were taken in an unpoled state. For the thermal characterization, measurements at room temperature, of