Effect of Nanoscale Surface Roughness and Electron-Phonon Interaction on Vibrational Modes of Cadmium Telluride Using Resonant Raman Spectroscopy.

This study investigates the combined effects of nanoscale surface roughness and electron-phonon interaction on the vibrational modes of cadmium telluride (CdTe) using resonant Raman spectroscopy. Raman spectra simulations aided in identifying the active phonon modes and their dependence on roughness. Our results reveal that increasing surface roughness leads to an asymmetric line shape in the first-order longitudinal optical (1LO) phonon mode, attributed to an increase in the electron-phonon interaction.

Impact of the preservation media on ex vivo bone samples for full field mechanical testing.

The preservation method to store bone tissue for posterior analysis is a widespread practice. However, the method's potential influence on the material's mechanical properties is often overlooked during single-point experimentation. Saline and formaldehyde solutions are the most common among the employed preservation media.

Flame analysis using a simple transmission digital holographic interferometer.

A digital holographic interferometer using a collimated beam in transmission mode to illuminate a flow coming from a diffusion flame is presented. The optical system proposes an indirect visualization of the flow to avoid saturation at the sensor. It can detect the intensity signal as a classical schlieren technique and the phase changes due to the presence of the flow.

Variability and composition of calcium oxalate crystals in embryos-seedlings-adult plants of the globose cacti Mammillaria uncinata.

The morphology and elemental composition of crystals in embryos, seedlings and adult plants of the globose cacti Mammillaria uncinata were studied. Samples of mature fruits and adult plants were collected. To obtain embryos and seedlings, seeds from mature fruits were germinated under laboratory conditions.

Electricity generation from Nopal biogas effluent using a surface modified clay cup () microbial fuel cell.

A modified clay cup (cantarito) microbial fuel cell (C-MFCs) was designed to digest the biomass effluent from a nopal biogas (NBE). To improve the process, commercial acrylic varnish (AV) was applied to the C-MFCs. The experiment was performed as:Both-C-MFCs, painting of AV on both sides of the clay cup; In-C-MFCs, painting of AV on the internal side, and Out-C-MFCs painting of AV on the external side.

Cortical bone quality affectations and their strength impact analysis using holographic interferometry.

It is now accepted that bone strength is a complex property determined mainly by three factors: quantity, quality and turnover of the bone itself. Most of the patients who experience fractures due to fragility could never develop affectations related to bone mass density (i.e.

Mach-Zehnder Stationary Two-Beam Spectroscopy Using Compound Prisms.

An interferometric optical setup for diffraction-less spectroscopy is tested as an optical design for control of interference frequency. Its design is based on a Mach-Zehnder interferometer in which a pair of compound prisms is introduced in the interferometer path to obtain interference patterns, which avoids the diffraction phenomena and nonlinear dispersion found on spectrometers that use gratings. Computer simulations of the interference patterns generated by the proposed optical setup are presented, and confirmed by the experimental results of the optical implementation.

Multiwavelength Raman Spectroscopic Analysis of Superficial Iron-Chromium Oxides Generated Using Laser Irradiation.

In order to characterize iron-chromium oxides generated by laser irradiation on the surface of stainless steel plates, an ultraviolet-visible (UV-Vis) near-infrared (NIR) multiwavelength excitation Raman analysis has been performed using both austenitic SS304 and ferritic SS430 stainless steel samples. Raman spectra were obtained using five different excitation wavelengths from blue (455 nm) to NIR (830 nm). These measurements have allowed us to observe and identify four Raman bands, among which two have not been previously observed for iron-chromium oxides, and characterize the existence of different resonant excitation conditions for the different excitation wavelengths.

Raman spectroscopy study of calcium oxalate extracted from cacti stems.

To find markers that distinguish the different Cactaceae species, by using near infrared Raman spectroscopy and scanning electron microscopy, we studied the occurrence, in the stem, of solid deposits in five Cactaceae species (Coryphantha clavata, Ferocactus latispinus, Opuntia ficus-indica, O. robusta, and O. strepthacantha) collected from their natural habitats from a region of México.

Knowledge discovery in spectral data by means of complex networks.

In the last decade, complex networks have widely been applied to the study of many natural and man-made systems, and to the extraction of meaningful information from the interaction structures created by genes and proteins. Nevertheless, less attention has been devoted to metabonomics, due to the lack of a natural network representation of spectral data. Here we define a technique for reconstructing networks from spectral data sets, where nodes represent spectral bins, and pairs of them are connected when their intensities follow a pattern associated with a disease.

Development of a method based on chemometric analysis of Raman spectra for the discrimination of heterofermentative lactobacilli.

In this work, a method based on Raman spectroscopy in combination with Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA) has been developed for the rapid differentiation of heterofermentative related lactobacilli. In a first approach, Lactobacillus kefir strains were discriminated from other species of heterofermentative lactobacilli: Lb. parakefir and Lb.

Detection of the presence of antibodies against Toxoplasma gondii in human colostrum by Raman spectroscopy and principal component analysis.

More than 60 million people in the United States and 23 million people in Mexico probably are infected with the Toxoplasma parasite, but very few have symptoms because the immune system usually keeps the parasite from causing illness. However, for people whose immune system is compromised, the consequences can be fatal. Toxoplasmosis is detected indirectly by different serological tests, where the sample requires a previous preparation.

Quantitative NIR-Raman analysis of methyl-parathion pesticide microdroplets on aluminum substrates.

The potential of Raman spectroscopy in the quantitative analysis of dilute organic contaminants on aluminum substrates is evidenced in this work. Methyl-parathion microdroplets, an organophosphorus pesticide, has been used as a probe for this purpose. The samples were analyzed on an aluminum foil, which is very easy to acquire and to adapt.

Quantitative NIR Raman analysis in liquid mixtures.

The capability to obtain quantitative information of a simple way from Raman spectra is a subject of considerable interest. In this work, this is demonstrated for mixtures of ethanol with water and rhodamine-6G (R-6G) with methanol, which were analyzed directly in glass vessel. The Raman intensities and a simple mathematical model have been used and applied for the analysis of liquid samples.