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This study deals with the problem of estimating the amount of biomass and lactic acid concentration in a lactic acid production process. A continuous stirred tank bioreactor was used for the culture of Lactobacillus helveticus. A nonlinear sliding mode observer is proposed and designed, which gives an estimate of both the biomass and lactic acid concentrations as a function of glucose uptake from the culture medium. Numerical results are given to illustrate the effectiveness of the proposed observer against a standard sliding-mode observer. It was found that the proposed observer worked very well for the benchmark bioreactor model. Also, the numerical results indicated that the proposed estimation methodology was robust to the uncertainties associated with un-modelled dynamics. These new sensing technologies, when coupled to software models, improve performance for smart process control, monitoring, and prediction.

Several epidemiological studies have suggested that phenolics have antineoplastic activities. The objective of this study was to determine the antiproliferative effect of rich phenolics extracts of mandarin (Citrus reticulate) and lime (Citrus aurantifolia) fruit waste in colorectal cancer cells, RKO (carcinom) and HT-29 (adenocarcinom). Antiproliferative effect was evaluated using the methylthiazolydiphenyl-tetrazolium bromide (MTT) assay and testing phenolics extracts from different mandarin and lime fruit waste drying temperatures (fresh, 60, 90, 120oC), at different times (24, 48 and 72 h). Mandarin and lime phenolics extracts inhibit cell viability of colon cancer cell lines, HT-29 and RKO, at 24 h to 72 h. Results suggested that phenolics extracts had different action mechanisms on each type of cells and therefore, more studies were required to elucidate such mechanisms.

Las fresas son frutos con una vida de anaquel corta debido a su elevada pérdida de humedad y a la sensibilidad al ataque de microorganismos. El objetivo del presente trabajo fue evaluar el efecto de los recubrimientos de quitosano adicionados con el extracto acuoso de hoja de Moringa oleifera en las propiedades fisicoquímicas. El extracto acuoso de hoja de Moringa se obtuvo mediante el método de extracción por ultrasonificación y microondas asistida. Se ensayaron dos formulaciones como recubrimientos y un control. Los parámetros evaluados fueron; pérdida de peso, pH, acidez titulable, sólidos solubles totales, índice de sabor y color (Hue, L* y croma). El método de extracción por ultrasonido y microondas es eficaz para evitar el uso de solventes y reducir el tiempo de extracción. Los recubrimientos aplicados mejoraron el índice de sabor y disminuyeron los valores de acidez titulable (AT) mejorando así, la dulzura de la fresa.

The cherimoya ( Annona cherimola Mill.) is a fruit crop with worldwide commercial importance. However, its distribution and potential growing regions of cherimoya are not defined for Mexico. That is why, this research aims to map the natural distribution of cherimoya and different eco-climatic regions where it is grown in Mexico as well as to map the climatic adaptability with the current climate and a prospection with the climate change scenario, all by different models of GIS. The general distribution model of cherimoya in Mexico showed that it had a chance to find cherimoya “in a natural way” in the biogeographic provinces Trans-Mexican Volcanic Belt, Sierra Madre del Sur and Highlands of Chiapas. Three eco-climatic groups were found in the distribution of cherimoya that corresponded to climates C(m)(w) , (A)C(e’) , and (A)C(e) , respectively. Where the group with climate (A)C(e) had the most restricted distribution. The potential growing regions of excellent adaptation of cherimoya were found in the biogeographic provinces of Trans-Mexican Volcanic Belt, Sierra Madre Occidental, Sierra Madre Oriental, Sierra Madre del Sur and Highlands of Chiapas. Finally, based on eco-crop modelling, it is concluded that climate change will not greatly affect areas of excellent adaptation of cherimoya in Mexico.

El análisis de eigenvalores o eigenanálisis es una técnica matemática, descrita dentro del álgebra lineal, con utilidad en distintas ramas de la ciencia. En este trabajo se hizo la revisión para dos casos específicos, en los cuales esta técnica matemática tiene connotaciones e interpretaciones diferentes. En el primer caso —el análisis de diversidad biológica—, se revisaron los tres análisis factoriales principales: en componentes principales, en coordenadas principales y de correspondencias. En todos se dio una interpretación similar: representar en un plano euclidiano la variabilidad de m unidades experimentales con n variables evaluadas, donde se ocupan tanto los eigenvalores como los eigenvectores. En el segundo caso —la estabilidad de reactores biológicos—, se analizan los eigenvalores de la matriz de estado del biorreactor para definir e interpretar su estabilidad. Esta revisión ofrece una lectura complementaria sobre el uso e interpretación del eigenanálisis para estudios de diversidad biológica y estabilidad de biorreactores.

La cromatografía de Pfaiffer es una técnica de análisis cualitativo que se puede usar en suelos, compostas y biofertilizantes, pudiendo observar rápidamente la relación que guardan los microorganismos, la materia orgánica y los minerales, como elementos que los componen. Para el productor agrícola es importante saber las condiciones del suelo o insumos que utiliza para obtener mejores resultados en sus cultivos. El objetivo del trabajo, fue realizar la cromatografía de Pfaiffer para analizar los suelos de sistemas productivos y comparar algunas características cualitativas. Las muestras de suelo fueron tomadas al azar de diferentes parcelas, el primero con manejo agronómico convencional, el siguiente de un terreno con producción de temporal y el último de un sistema de producción orgánico, fueron analizados mediante la cromatografía de Pfaiffer por separado. Se interpretaron los cromatogramas, pudiendo observar que los tres tipos de suelo proporcionan las características propias del sistema de labranza a que pertenecen.

Las microalgas son una alternativa para la obtencion de biodiesel por su alto rendimiento de lipidos y su perfil de acidos grasos. Objetivos. Hacer una revision sobre los avances y perspectivas actuales de la produccion de biodiesel a partir de microalgas. Metodos. Se realizo una busqueda actualizada de los trabajos de investigacion relacionados con la produccion de biodiesel a partir de microalgas, con especial enfasis en la biosintesis de acidos grasos y trigliceridos, la produccion de biomasa, las tecnicas de extraccion, los procesos biotecnologicos implementados en sistemas de cultivo, la transesterificacion y los sistemas de doble proposito. Resultados. Las microalgas tienen rendimientos altos de produccion de lipidos (59 m3 ha-1 ano-1), por lo que representa una alternativa para la obtencion de biodiesel; sin embargo, el costo de produccion y recuperacion de biomasa sigue siendo elevado ($5.8 USD Kg-1), aunado a los altos requerimientos energeticos (33 MJ Kg-1). Actualmente no existen tecnicas industriales factibles para la extraccion de lipidos y se estan probando los metodos por fluidos supercriticos, campo electrico de pulso, microondas y ultrasonicacion. La biotecnologia ha propuesto un novedoso sistema biologico mediante el uso de lipasas recuperadas de hongos filamentosos para el proceso de transesterificacion, los cuales ya son comerciales, y ha logrado rendimientos de biocatalisis mayores al 90%.Los “sistema de doble proposito” pueden ser optimizados utilizando un diseno modular que establezca los procesos y operaciones unitarias bien definidas. Conclusiones. El uso de microalgas para la obtencion de biodiesel representa una tecnica viable gracias a su alto contenido lipidico y a su perfil de acidos grasos, aunque hace falta el desarrollo de tecnologias que disminuyan el costo de produccion. El uso de sistemas de doble proposito se vislumbra como una buena opcion para reducir estos precios, al mismo tiempo que se reusan aguas residuales.

Fenofibrate, an oral fibrate lipid lowering agent, and simvastatin, which reduces plasma levels of low-density lipoprotein cholesterol, are active pharmaceutical ingredients (APIs), currently in the market. We characterized these APIs by thermal analysis and conducted X-ray powder diffraction techniques. Studies should be carried out in the formulation stage before the final composition of a polypill may be established. Thus, it was found in thermochemical studies that both compounds present no chemical interactions in an equimolar mixture of solid samples at room temperature. Theoretical studies were employed to determine possible interactions between fenofibrate and simvastatin. A very weak intramolecular hydrogen bond is formed between the hydroxyl group (O 5 H 5 ) of the simvastatin with chlorine and carbonyl group (C 11 O 4 , C 1 O 2 ) of the fenofibrate molecule. These weak energy hydrogen bonds have no effect on the chemical stability of the compounds studied. The results were obtained using Density Functional Theory methods; particularly the BPE1BPE and B3LYP functional and 6-31++G** basis set. The values of energy show good approximation when are compared with similar calculations previously reported. Infrared spectra of monomers and dimers were obtained via theoretical calculations.

Biocomposites of polylactic acid, thermoplastic starch, chitosan powder, and chitosan lyophilized powder were prepared using an extrusion process. The color, thermal, structural, mechanical, morphology, and antimicrobial properties were evaluated. The addition of thermoplastic starch and chitosan (chitosan powder and chitosan lyophilized powder) produced significant changes in color and heterogeneous surface morphology of the polylactic acid biocomposites. The thermal, mechanical, and morphometric properties of the material showed changes with the addition of thermoplastic starch and chitosan (chitosan powder and chitosan lyophilized powder). The biocomposites formulated with chitosan powder and chitosan lyophilized powder showed antifungal activity when evaluating this property. The biocomposites produced could be used in packaging applications.

There are a number of products obtained from the cochineal, including carmine which is used in oil-based products and cochineal extract used in water-based products. Both can be used in the manufacture of cosmetics. So the aim of this study was to measure the color of cosmetic products, shampoo and lipstick bullet, where the byproducts of cochineal were applied. The measurement was carried out using a colorimeter in the CIELab scale. Were observed the different values of the coordinates L *, a * and b * for the products.

The aim of this work was to analyze the performance of a wastewater system for Cr(VI) and sulfate compounds reduction via mathematical modeling. The considered process is coupled to chemical reactors to achieve its tasks. The first stage of the considered process is a biological sulfate-reducing reactor, by which sulfate compounds can be reduced to biogenic sulfide; then, in the second stage, the above-mentioned biogenic sulfide is fed to a second reactor in which the Cr(VI) is reduced, allowing high Cr(VI) concentration removal. The kinetic model of the biological sulfate-reducing process and the Cr(VI) reduction via biogenic sulfide reactions were experimentally corroborated and employed as a benchmarck for the wastewater process analysis via numerical simulations to achieve several feasible operation conditions, under the system’s constraints. The mathematical model was extended to a continuous operation, where numerical experiments were carried out predicting an excellent removal of 99% of Cr(...

A local analysis of stability and observability of the ethanol process are determined for continuous operation. It is found that the process is stable and noncompletely observable in the selected steady states. The analysis of observability was studied in terms of the observability matrix rank conditions. Furthermore, we design a nonlinear observer in order to estimate the observable state variables. The software sensor (state estimator) is developed considering only one measurable variable, the glucose concentration, and taking in account model uncertainties, which is a realistic issue. Some sufficient conditions for the existence of the proposed observer are obtained, which guarantee the convergence of the proposed methodology. The maximum ethanol production conditions are obtained by manipulating the dilution rate with optimal initial substrate concentration and the observable subspace is determinate which allows estimating six state variables (starch concentration, susceptible starch concentration, ethanol concentration, biomass concentration, glucose concentration and enzyme concentration). Numerical simulations are provided to show the effectiveness of the proposed observer where a comparison with a standard sliding-mode observer is done.

This paper presents a comparative analysis of two nonlinear state estimators applied to the production process of tequila. The estimates consist of an extended Kalman filter (EKF) and a sliding mode observer (SMO), which are assessed to changes in process inputs and model parametric changes. The estimates are used to estimate the microbial growth and production of alcohol from the measurement of glucose concentration in the fermentation tank. The performance of the estimators is evaluated in terms of indicators of error.

In this paper the design of state observers or software sensors for a biological process of ethanol production by S. cerevisiae is presented. Two observers (non-linear and sliding) were used for monitoring continuous fermentations. Their performances were evaluated using mathematical model for bioreactor (perfect knowledge of both model structure and parameters. The performance of the observers proposed in the present work showed a better adjustment that the classical Extended Luenberger observer.

El zapote mamey (Pouteria sapota H. E. Moore & Steam) es un frutal tropical nativo de Mexico con caracteristicas organolepticas y nutrimentales que son de interes comercial. El presente estudio tuvo como objetivo generar mapas de la distribucion geografica natural y eco-climatica donde se desarrolla el zapote mamey (Pouteria sapota H. E. Moore & Steam) en Mexico y modelar las zonas potenciales de acuerdo con el cambio climatico estimado para 2050. El modelo de distribucion natural mostro que esta especie se encuentra en la mayoria de las zonas tropicales y algunas subtropicales de Mexico. Esta especie se desarrolla en tres regiones eco-climaticas diferentes (dos tropicales y una subtropical) de climas: Aw (peninsula de Yucatan), Am (Golfo de Mexico) y A(C)(m) (norte del Golfo de Mexico y costa del Pacifico). El modelado de las zonas adecuadas de adaptacion climatica mostro que 15, de 32 entidades de Mexico, tienen potencial para cultivar zapote mamey; ademas, en el escenario de cambio climatico global, se pronostican efectos beneficos en la adaptacion de esta especie considerando la identificacion de al menos ochos estados mas con posibilidades favorables