Papers by Jose Abraham Balderas Lopez
High precision measurements of Thermal Diffusivity of liquids, using a liquid-compatible Thermal ... more High precision measurements of Thermal Diffusivity of liquids, using a liquid-compatible Thermal Wave Resonant Cavity (TWRC), are presented. The analytical procedure involved linear fittings to the photothermal signal’s amplitude as function of the cavity length. The thermal-diffusivities of distilled water, glycerol, olive oil and ethylene glycol were determined at room temperature (25 C), with four-significant-figure precision. The liquid-state TWRC was applied to the measurements of Thermal Diffusivity of various mixtures of methanol and salt in distilled water. The sensitivity limits were found to be 0.5 % (v/v) and 0.03 % (w/v), respectively. The use of the TWRC to measure gas evolution from liquids was explored by recording the sensor’s signal amplitude for carbonated water as CO2 was evolving. The obtained results show the TWRC potential for environmental applications.
In this paper the photoacoustic technique in the thermal-wave transmission configuration is appli... more In this paper the photoacoustic technique in the thermal-wave transmission configuration is applied to thermal diffusivity measurements in liquids. The one-dimensional heat diffusion problem involving three layers, and assuming surface absorption only, is solved for this goal. Linear relations among the photoacoustic amplitude (on a semi-log scale) and phase, as functions of the liquid sample thickness, are shown in each
Review of Scientific Instruments, 2003
The thermal wave resonator cavity (TWRC) was used to measure the thermal properties of vegetable ... more The thermal wave resonator cavity (TWRC) was used to measure the thermal properties of vegetable oils. The thermal diffusivity of six commercial vegetable oils (olive, corn, soybean, canola, peanut, and sunflower) was measured by means of this device. A linear relation between both the amplitude and phase as functions of the cavity length for the TWRC was observed and used for the measurements. Three significant figure precisions were obtained. A clear distinction between extra virgin olive oil and other oils in terms of thermal diffusivity was shown. The high measurement precision of the TWRC highlights the potential of this relatively new technique for assessing the quality of this kind of fluids in terms of their thermophysical properties.
Review of Scientific Instruments, 2003
A self-normalized photothermal method for measuring thermal diffusivity of thin metal layers has ... more A self-normalized photothermal method for measuring thermal diffusivity of thin metal layers has been implemented using two experimental configurations based on photothermal radiometry and gas-cell photoacoustic detection. The corresponding measurement procedures involve linear fits in the photothermally thin and/or thick limits. As part of this method, simple experimental criteria have been developed to ascertain that a purely thermal-diffusion-wave mechanism is dominant throughout the selected frequency range, thus validating the accuracy of the thermal diffusivity measurements. Thermal-diffusivity values measured using the intrinsic reliability of this self-normalized photothermal measurement scheme are reported for two commercial samples of aluminum and steel thin layers.
Journal of Applied Physics, 2002
The one-dimensional heat diffusion problem for a three-layer system is solved assuming the surfac... more The one-dimensional heat diffusion problem for a three-layer system is solved assuming the surface absorption model. The analytical solution is shown to be suitable for the implementation of normalized depth-profilometric photoacoustic methodologies involving the open photoacoustic-cell configuration for thermal diffusivity measurements in buried underlayers within a three-layer stack. Our normalization procedures eliminate the frequency-dependent instrumental electronic contribution (transfer function) and some thermophysically nonrelevant proportionality factors in the theoretical equations, thus making the depth-profilometric analysis feasible. The measurement methodology is achieved by normalizing the theoretical photoacoustic signal from the three layers with the corresponding signal from the uppermost two layers, involving linear fits to measure the thermal diffusivity of the third underlayer. Three different multilayered materials were examined using the proposed methodologie...
Journal of Applied Physics, 2000
Two self-normalized photothermal techniques, to carry out thermal diffusivity measurements of con... more Two self-normalized photothermal techniques, to carry out thermal diffusivity measurements of condensed phase materials, are presented. These simple methodologies involve linear fitting procedures of the signal amplitude and phase. These procedures lead to the elimination of the usual requirement for instrumental transfer-function normalization. The thermal diffusivities for two dental resins and two pure liquids are measured with these simple methodologies and very good agreement is found with values reported in the literature, where more involved analysis is usually required.
International Journal of Thermophysics
International Journal of Thermophysics, 2020
Avances de investigación en Nanociencias, Micro y Nanotecnologías. Volumen II, 2020
En las últimas décadas, la nanotecnología ha emergido como un área de investigación que está enco... more En las últimas décadas, la nanotecnología ha emergido como un área de investigación que está encontrando aplicaciones en múltiples campos. El mercado actual incluye nanomateriales que proporcionan grandes ventajas sobre los materiales en su forma convencional, una de éstas, su mayor área de contacto, lo que los hace ideales como sustancias catalíticas, mejorando este tipo de procesos con la consecuente reducción de insumos. Dentro de los nanomateriales comúnmente utilizados, las nanopartículas de oro se han aplicado principalmente en biomedicina, salud y belleza, sector automotriz y electrónica. Sin embargo, el uso cada vez más generalizado de nanopartículas no va aparejado con estudios sobre el impacto ambiental que conlleva la disposición final de sus residuos, especialmente en medios acuáticos, destino habitual de muchas sustancias utilizadas en procesos industriales, los cuales han sido poco estudiados. La presente investigación aborda el efecto que tienen las nanopartículas de ...
Nanoscale Research Letters, 2019
Brazilian Journal of Physics, 2015
Revista Mexicana de Fisica
Review of Scientific Instruments, 1999
In this article, we present a new photoacoustic technique, based on the conventional photoacousti... more In this article, we present a new photoacoustic technique, based on the conventional photoacoustic configuration, to characterize the thermal effusivity of liquid samples. This new technique is applicable for all kind of liquid samples, including the nontransparent ones. In order to show the usefulness of this new technique, we measured the thermal effusivity of a variety of liquid samples including: distilled water, ethanol, methanol, chloroform, glycerol, and car oil. The comparison with literature values shows a remarkable agreement. Also, we show measurements of the thermal effusivity of acetone in distilled water mixtures, showing the graphical dependence of this thermal property with the concentration of one of the components.
Review of Scientific Instruments, 1996
In this article, we present a new CO2 analyzer which can be used for monitoring respiration rates... more In this article, we present a new CO2 analyzer which can be used for monitoring respiration rates in organic material. To demonstrate the potentiality of the analyzer, CO2 evolution of soil samples collected from three different edaphic environments were measured. The results obtained with this compact CO2 analyzer were compared with those carried out simultaneously using the chemical method, and the correlation between them has been established.
ABSTRACT In this paper, we discuss the usefulness of photoacoustic techniques for characterizing ... more ABSTRACT In this paper, we discuss the usefulness of photoacoustic techniques for characterizing the thermal properties of wood. In particular, we also present a new photoacoustic-based detection technique for the measurement of the water vapor diffusion coefficient in wood. The environmental implications of these results that relate to the daily life of rural populations are briefly considered.
Review of Scientific Instruments, 2000
A liquid-ambient-compatible thermal wave resonant cavity (TWRC) has been constructed for the meas... more A liquid-ambient-compatible thermal wave resonant cavity (TWRC) has been constructed for the measurement of the thermal diffusivity of liquids. The thermal diffusivities of distilled water, glycerol, ethylene glycol, and olive oil were determined at room temperature (25 °C), with four-significant-figure precision as follows: (0.1445±0.0002)×10−2 cm2/s (distilled water); (0.0922±0.0002)×10−2 cm2/s (glycerol); (0.0918±0.0002)×10−2 cm2/s (ethylene glycol); and (0.0881±0.0004)×10−2 cm2/s (olive oil). The liquid-state TWRC sensor was found to be highly sensitive to various mixtures of methanol and salt in distilled water with sensitivity limits 0.5% (v/v) and 0.03% (w/v), respectively. The use of the TWRC to measure gas evolution from liquids and its potential for environmental applications has also been demonstrated.
International Journal of Thermophysics, 2018
Thermochimica Acta, 2019
Mineral oils are used in electric power transformers for their excellent dielectric properties. T... more Mineral oils are used in electric power transformers for their excellent dielectric properties. The continuous
exposition to electrical discharges and thermal stresses may cause chemical adulteration in these substances
which eventually could be cause of electrical catastrophic fails in the transformers. It is then important to
evaluate periodically the quality of the oils to prevent major damages. The technique currently used for such
purposes is gas chromatography, however its high inaccuracy iswell known. Chemical transformation of aged
oils changes their thermal and optical properties and these could be used as alternative parameters for diagnostic
purposes of electric power transformers. In this paper two configurations of photopyroelectric techniques were
used for optical absorption coefficient (at 405 nm) and thermal diffusivity measurements of mineral oils aged up
to 2300 h under controlled conditions. It was found that, at least up to this period of aging time, thermal
diffusivity does not show significant differences, optical absorption coefficient at 405 nm, on the other hand,
showed significant differences starting at 1000 h and then this optical parameter can potentially be used for
diagnostic purposes.
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Papers by Jose Abraham Balderas Lopez
exposition to electrical discharges and thermal stresses may cause chemical adulteration in these substances
which eventually could be cause of electrical catastrophic fails in the transformers. It is then important to
evaluate periodically the quality of the oils to prevent major damages. The technique currently used for such
purposes is gas chromatography, however its high inaccuracy iswell known. Chemical transformation of aged
oils changes their thermal and optical properties and these could be used as alternative parameters for diagnostic
purposes of electric power transformers. In this paper two configurations of photopyroelectric techniques were
used for optical absorption coefficient (at 405 nm) and thermal diffusivity measurements of mineral oils aged up
to 2300 h under controlled conditions. It was found that, at least up to this period of aging time, thermal
diffusivity does not show significant differences, optical absorption coefficient at 405 nm, on the other hand,
showed significant differences starting at 1000 h and then this optical parameter can potentially be used for
diagnostic purposes.
exposition to electrical discharges and thermal stresses may cause chemical adulteration in these substances
which eventually could be cause of electrical catastrophic fails in the transformers. It is then important to
evaluate periodically the quality of the oils to prevent major damages. The technique currently used for such
purposes is gas chromatography, however its high inaccuracy iswell known. Chemical transformation of aged
oils changes their thermal and optical properties and these could be used as alternative parameters for diagnostic
purposes of electric power transformers. In this paper two configurations of photopyroelectric techniques were
used for optical absorption coefficient (at 405 nm) and thermal diffusivity measurements of mineral oils aged up
to 2300 h under controlled conditions. It was found that, at least up to this period of aging time, thermal
diffusivity does not show significant differences, optical absorption coefficient at 405 nm, on the other hand,
showed significant differences starting at 1000 h and then this optical parameter can potentially be used for
diagnostic purposes.