Evaluation of the aspherical surface of a plano-convex lens by refraction using an LCD.

We present a simple method to evaluate the curved surface of a plano-convex aspheric lens using an incoherent light source. We implement an exact ray trace to obtain analytical expressions for designing a set of geometric objects, placed within a plane, to produce by refraction a regular array of either circles or straight lines in the plane of detection when the optical system under test works in accordance with the nominal design. An innovative geometrical test is implemented to calibrate the position of each element involved in the measurement system.

Design of freeform mirrors using the concentric rings method.

Through the methodology of optical surface design based on concentric rings, this paper proposes the design of freeform mirrors, initially by employing segmented rings, each of them with different spherical radii of curvature, and then by employing segmented conic rings with different conic constants in each of the segments. These surfaces will then produce the desired images. For the case of segmented spherical rings, mathematical expressions were deduced to obtain the image points as a function of the radii of curvature.

Preliminary Analysis of Unsaturated Fatty Acid Profiles of Coffea arabica L., in Samples with a Denomination of Origin and Speciality of Oaxaca, Mexico.

In February 2020, Coffea arabica L. grown on the coast and in the Southern Sierra Madre of the state of Oaxaca, Mexico obtained the denomination of origin. Which does not have data on color and chemical composition, the first associated with the degree of roasting and the second with lipids (17-18%), as the group of compounds responsible, in part, for flavor, consistency, and may contribute to health benefits.

Oxidative stability in raw, cooked, and frozen ground beef using Epazote (Chenopodium ambrosioides L.).

This study investigated the potential of aqueous epazote (AE) and ethanolic extract of epazote (ETHE) as inhibitors of lipid oxidation in raw and cooked ground beef stored at 4 °C for 9 days as well as frozen beef patties stored at -18 °C for 90 days. Organic acids were identified in AE and ETHE using ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-qTOF). Chemical composition, TBARS, pH, colour, sensory acceptability and intensity of oxidised flavour were analysed in the three different meat products.

PDMS samples characterization with variations of synthesis parameters for tunable optics applications.

PDMS has become a frequently used material in the elaboration of optical components such as: variable focal length liquid lenses, optical waveguides, solid elastic lenses, etc. In this work we describe the elaboration of PDMS samples, and we present the physical and optical properties of the material when a variation on its synthesis parameters (mixture ratio of base: curing agent, curing temperature and curing time) is implemented during their elaboration. Tensile and compressive tests were carried out to obtain the corresponding stress-strain curves of the material, and UV-Vis spectroscopy was applied to obtain transmittance and absorbance curves of the samples.

Food Safety through Natural Antimicrobials.

Microbial pathogens are the cause of many foodborne diseases after the ingestion of contaminated food. Several preservation methods have been developed to assure microbial food safety, as well as nutritional values and sensory characteristics of food. However, the demand for natural antimicrobial agents is increasing due to consumers' concern on health issues.

Representation Learning for Class C G Protein-Coupled Receptors Classification.

G protein-coupled receptors (GPCRs) are integral cell membrane proteins of relevance for pharmacology. The complete tertiary structure including both extracellular and transmembrane domains has not been determined for any member of class C GPCRs. An alternative way to work on GPCR structural models is the investigation of their functionality through the analysis of their primary structure.

Natural antioxidant extracts as food preservatives.

The food industry is becoming more specialized and processing methods are continuously being developed to meet consumer needs. Consumers demand products that are safe and preferably free of synthetic additives. These additives are associated with health effects, in most cases without reasonable justification.

Effect of vacuum ageing on quality changes of lamb steaks from early fattening lambs during aerobic display.

The effects of vacuum ageing on the quality changes of lamb steaks during retail display were assessed. Biceps femoris and Quadriceps femoris muscles from thirty early fattening lambs fed barley straw and concentrate or alfalfa and concentrate were used. Half of the muscles were vacuum aged for three weeks (VA), and the other half were not aged (control).

Quality characteristics of a dry-cured lamb leg as affected by tumbling after dry-salting and processing time.

The aim of this study was to evaluate selected quality characteristics of a dry-cured lamb leg with different tumbling treatments after salting. The characteristics were measured at different processing times. Three batches of dry-cured lamb legs (nine legs per batch) were prepared with no-, short- and long-tumbling treatments, and microbial counts, NaCl, aw, proximate composition, pH, free fatty acids, water soluble nitrogen, volatile compounds, texture and colour were evaluated at days 1, 22 and 71 of processing.

Estimation of phoneme-specific HMM topologies for the automatic recognition of dysarthric speech.

Dysarthria is a frequently occurring motor speech disorder which can be caused by neurological trauma, cerebral palsy, or degenerative neurological diseases. Because dysarthria affects phonation, articulation, and prosody, spoken communication of dysarthric speakers gets seriously restricted, affecting their quality of life and confidence. Assistive technology has led to the development of speech applications to improve the spoken communication of dysarthric speakers.

Recognition of emotions in Mexican Spanish speech: an approach based on acoustic modelling of emotion-specific vowels.

An approach for the recognition of emotions in speech is presented. The target language is Mexican Spanish, and for this purpose a speech database was created. The approach consists in the phoneme acoustic modelling of emotion-specific vowels.

On the development of speech resources for the Mixtec language.

The Mixtec language is one of the main native languages in Mexico. In general, due to urbanization, discrimination, and limited attempts to promote the culture, the native languages are disappearing. Most of the information available about the Mixtec language is in written form as in dictionaries which, although including examples about how to pronounce the Mixtec words, are not as reliable as listening to the correct pronunciation from a native speaker.

Economic Statistical Design of integrated X-bar-S control chart with Preventive Maintenance and general failure distribution.

The application of Preventive Maintenance (PM) and Statistical Process Control (SPC) are important practices to achieve high product quality, small frequency of failures, and cost reduction in a production process. However there are some points that have not been explored in depth about its joint application. First, most SPC is performed with the X-bar control chart which does not fully consider the variability of the production process.