Phosphoric Acid Industry: Problems and Solutions

Phosphoric acid (PA) is an important industrial chemical used as an intermediate in the fertilizer industry, for metal surface treatment in the metallurgical industry and as an additive in the food industry. The PA industry is spread out worldwide in Europe, Asia and America, including countries that operate phosphate rock (PR) mines and produce PA, phosphatic fertilizers and phosphate-based products

Desarrollo y caracterización de películas activas con nanopartículas de plata obtenidas mediante síntesis verde

The use of edible films is a technology to extend the shelf life of food. The addition of silver nanoparticles (AgNPs) could improve the performance of edible films and avoid the growth of microorganisms that could affect food. The objective was to elaborate and characterize AgNPs by green synthesis and to evaluate the effect of their addition on the mechanical and barrier properties of films formed from Cajanus cajan protein and Tamarindus indica seed gum. An aqueous extract of Annona muricata leaves was used for green synthesis. Three films were developed containing AgNPs, aqueous extract of Annona muricata leaves and water (control). Films were evaluated by their water vapour permeability (WVP), color, opacity and mechanical properties. The AgNPs increased twice the Young's module (0.0675 MPa) and the tensile strength (2.84 MPa) in relation to control film. Moreover, the AgNPs influenced also the color and opacity of the films. However, no differences were observed in the WVP. The addition of AgNPs to films, could be an option to increase the shelf life of foods.El uso de películas comestibles es una tecnología para alargar la vida útil de los alimentos. La adición de nanopartículas de plata (AgNPs) podría mejorar el desempeño de películas comestibles y evitar el crecimiento de microorganismos que podrían afectar a los alimentos. El objetivo fue elaborar y caracterizar AgNPs mediante síntesis verde y evaluar el efecto de su adición sobre las propiedades mecánicas y de barrera de películas formadas a partir de proteína de Cajanus cajan y goma de la semilla de Tamarindus indica. Para la síntesis de AgNPs se utilizó extracto acuoso de Annona muricata. Tres diferentes formulaciones de películas se elaboraron las cuales contenían AgNPs, extracto acuoso de guanábana y agua (control). Las películas fueron evaluadas en términos de su permeabilidad al vapor de agua (WVP), color, opacidad y propiedades mecánicas. Las AgNPs incrementaron el doble el módulo de Young de las películas (0.0675 MPa) y la fuerza de tensión (2.84 MPa) con respecto al control. Además, las AgNPs influyeron estadísticamente en el color y opacidad de la película. Sin embargo, no se observaron diferencias en la PVA. La adición de AgNPs a recubrimientos podría ser una opción para incrementar la vida útil de alimentos

Enterobacter cloacae, an Endophyte That Establishes a Nutrient-Transfer Symbiosis With Banana Plants and Protects Against the Black Sigatoka Pathogen

Banana (Musa spp.) is an important crop worldwide, but black Sigatoka disease caused by the fungus Pseudocercospora fijiensis threatens fruit production. In this work, we examined the potential of the endophytes of banana plants Enterobacter cloacae and Klebsiella pneumoniae, as antagonists of P. fijiensis and support plant growth in nutrient limited soils by N-transfer. The two bacterial isolates were identified by MALDI-TOF mass spectrometry and corroborated by 16S rRNA sequence analysis. Both bacteria were positive for beneficial traits such as N-fixation, indole acetic acid production, phosphate solubilization, negative for 1-aminocyclopropane 1-carboxylic acid deaminase and were antagonistic to P. fijiensis. To measure the effects on plant growth, the two plant bacteria and an E. coli strain (as non-endophyte), were inoculated weekly for 60 days as active cells (AC) and heat-killed cells (HKC) into plant microcosms without nutrients and compared to a water only treatment, and a mineral nutrients solution (MMN) treatment. Bacterial treatments increased growth parameters and prevented accelerated senescence, which was observed for water and mineral nutrients solution (MMN) treatments used as controls. Plants died after the first 20 days of being irrigated with water; irrigation with MMN enabled plants to develop some new leaves, but plants lost weight (−30%) during the same period. Plants treated with bacteria showed good growth, but E. cloacae AC treated plants had significantly greater biomass than the E. cloacae HKC. After 60 days, plants inoculated with E. cloacae AC showed intracellular bacteria within root cells, suggesting that a stable symbiosis was established. To evaluate the transference of organic N from bacteria into the plants, the 3 bacteria were grown with 15NH4Cl or Na15NO3 as the nitrogen source. The 15N transferred from bacteria to plant tissues was measured by pheophytin isotopomer abundance. The relative abundance of the isotopomers m/z 872.57, 873.57, 874.57, 875.57, 876.57 unequivocally demonstrated that plants acquired 15N atoms directly from bacterial cells, using them as a source of N, to support plant growth in restricted nutrient soils. E. cloacae might be a new alternative to promote growth and health of banana crops

Educación Tecnológica: preparación de la juventud para su incorporación en la sociedad moderna

La educación tecnológica es parte integral de un sistema de desarrollo económico, cuya misión es incorporar a la enseñanza el progreso científico y tecnológico. La tecnología trasciende su dimensión técnica para ofrecer a la sociedad servicios útiles, ejerciendo una influencia positiva a través de la enseñanza, el aprendizaje y el entrenamiento laboral. Así, la ciencia, la educación, la tecnología y la producción se unen para formar el círculo del progreso y la modernización

La ética profesional desde la perspectiva de los alumnos de ingeniería de una universidad pública

Engineering is one of the most common degrees currently required by companies which require more and more trained professionals in the technical and humanistic aspect. Within the humanist competencies, ethical values are dominant. his research aims to explore and understand the level of perspective that engineering students have at the Polytechnic University of Baja California, on professional ethics, that allows to know its critical thinking and its application in the professional practice. Findings of the application of a questionnaire are presented, with encouraging results. However, it is considered to establish strategies for the optimization of competencies for future professionals that will help them face the complex changes of this increasingly demanding world of professionals who are integrated into a globalized environment and contribute to the construction of a knowledge societyLa ingeniería es una de las carreras con mayor demanda en la actualidad, las empresas requieren cada vez más profesionales entrenados en el aspecto técnico y humanista. Dentro de las competencias humanistas es preponderante los valores éticos. Esta investigación tiene por objetivo explorar y conocer el nivel de perspectiva que tiene los alumnos de ingeniería de la Universidad Politécnica de Baja California, sobre la ética profesional, que permita conocer su pensamiento crítico y su aplicación en el ejercicio profesional. Se presentan los hallazgos de la aplicación de un cuestionario, con resultados alentadores, sin embargo, se considera establecer estrategias para la optimización de competencias para los futuros profesionistas que les ayude a enfrentar los complejos cambios de este mundo cada vez más demandante de profesionistas que se integren a un ambiente globalizado y contribuyan a la construcción de una sociedad del conocimiento

Antifungal Effects of Silver Phytonanoparticles from Yucca shilerifera Against Strawberry Soil-Borne Pathogens: Fusarium solani and Macrophomina phaseolina

In the present study, the characterization and properties of silver nanoparticles from Yucca shilerifera leaf extract (AgNPs) were investigated using UV–visible spectroscopic techniques, zeta potential, and dynamic light scattering. The UV–visible spectroscopic analysis showed the absorbance peaked at 460 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 729 nm with lower stability (195.1 mV). Additionally, our dates revealed that AgNPs showed broad spectrum antagonism (p ≤ .05) against Fusarium solani (83.05%) and Macrophomina phaseolina (67.05%) when compared to the control after nine days of incubation. Finally, AgNPs from leaf extracts of Y. shilerifera may be used as an agent of biocontrol of microorganism of importance. However, further studies will be needed to fully understand the agronanotechnological potentialities of AgNPs from Yucca schidigera

Interesting Behavior of Pachycormus discolor Leaves Ethanol Extract as a Corrosion Inhibitor of Carbon Steel in 1 M HCl: A Preliminary Study

The purpose of this paper is to evaluate the inhibitive action of an ethanol extract from the leaves of Pachycormus discolor (EEPD) on the corrosion of carbon steel in 1 M HCl at different temperatures; gravimetric method and electrochemical tests were conducted. Potentiodynamic polarization was used at room temperature and resistance polarization at different temperatures. Thermodynamic adsorption parameters are shown in order to demonstrate the spontaneous adsorption. The inhibition of EEPD was performed via adsorption of the extract species on the carbon steel surface. The ethanol extract obeys Langmuir adsorption isotherm. Potentiodynamic polarization results indicate that the ethanol extract acts as a mixed type inhibitor. The results revealed that the inhibition efficiency (IE) of EEPD increases (when the concentration is increased). Phytochemical and FTIR analyses are also presented in this work. It was found that the IE increases with the temperature in a 2.0% v/v solution which showed 94.52% IE at 25∘C and 97.89% at 75∘C

Movilidad social en los graduados de Ingeniería de la Universidad Politécnica de Baja California

This article describes the social mobility in relation to the perceived monthly income of graduates from the Polytechnic University of Baja California. Information was obtained through a survey of 154 graduates in Energy Engineering, Information Technology, Manufacturing Technology and Mechatronics Engineering 2009 to 2018 period, describing: First, economic income in accordance with the academic program, second, first professional generation and finally third, gender. The comparison was made at statements in time: between the first to enter college and the second to be graduated. From these data it describes whether academic programs allow social mobility economically. On the context that educational training and the labor market influence the personal and professional development of graduates. The results indicate that better income and employability of graduates is due to its technological training.Este artículo describe la movilidad social con relación a los ingresos mensuales percibidos de los egresados de la Universidad Politécnica de Baja California. Se obtuvo información a través de una encuesta aplicada a 154 graduados de Ingeniería en Energía, Tecnologías de la Información, Tecnologías de Manufactura e Ingeniería Mecatrónica del periodo 2009 al 2018, describiendo: primero ingresos económicos de acuerdo con el programa académico, segundo: primera generación de profesionista y tercero: género. Se realizó la comparación en dos momentos en el tiempo: el primero al ingresar a la universidad y al haber egresado. A partir de estos datos se describe si los programas académicos permiten tener movilidad social de tipo económico. Tomando como contexto que la formación educativa y el mercado laboral influyen en el desarrollo profesional y personal de los egresados. Los resultados indican que los mejores ingresos y empleabilidad de los egresados se debe a su formación tecnológica