Bloques de Tierra Comprimida (BTC) estabilizados con cal y cemento. Evaluación de su impacto ambiental y su resistencia a compresión

This work presents the evaluation of the environmental impact and compressive strength of Compressed Earth Blocks (CEB) stabilized with hydrated aerial lime and Portland cement. For this, 12 series of blocks stabilized with different proportions of lime and cement were manufactured and the Life Cycle Analysis (LCA) methodology was used. After conducting these assays and simulations, it could be concluded that, using earth and sand typical of the city of Santa Fe (Argentina), stabilized with certain percentages of Portland cement between 5 and 10% in weight, CEB can be produced with sufficient levels of strength for them to be used in load-bearing walls, in this way minimizing the negative environmental impact associated with their manufacturing. It is also concluded that the stabilization with aerial lime does not increase the CEB’s compressive strength and, on the contrary, significantly increases their negative impact on the environment.En este trabajo se presenta la evaluación del impacto ambiental y la resistencia a compresión de Bloques de Tierra Comprimida (BTC) estabilizados con cal aérea hidratada y cemento Portland. Para esa labor, se fabricaron 12 series de bloques estabilizados con diferentes proporciones de cal y cemento y se empleó la metodología del Análisis de Ciclo de Vida (ACV). Tras la realización de los ensayos y las simulaciones pudo concluirse que, usando suelos y arena característicos de la ciudad de Santa Fe (Argentina), estabilizados con determinados porcentajes de cemento Portland -comprendidos entre el 5 y el 10% en peso- pueden producirse BTC con niveles de resistencia suficientes para ser utilizados en muros de carga y, de esa forma, minimizar el impacto ambiental negativo asociado a su fabricación. Se concluye, además, que la estabilización con cal aérea no incrementa la resistencia a compresión de los BTC y aumenta, por el contrario, de manera significativa el impacto negativo de éstos sobre el medio ambiente

Influence of the Global Charge of the Protein on the Stability of Lysozyme–AuNP Bioconjugates

The structural organization of the proteins that interact with a metallic nanoparticle and form the protein corona is the relevant biological information to take into account in the design of bionanoconjugates. We have studied the interaction of the protein Lysozyme (LYZ) with gold nanoparticles (AuNPs) protected by citrate, 6-mercaptopurine and -mercaptoundecanoic acid monolayers in aqueous solution in a wide pH range. The bioconjugates are stables at pH higher than the isoelectric point (pI) of LYZ. At lower pH, flocculation occurs possibly by interactions between the exposed positive charges of the protein. The modification of the Lys residues of the protein by either succinylation or phosphopyridoxylation brings about important changes in the flocculation behavior of the bioconjugates. By taking into account the location of the modified residues in the protein three-dimensional structure, a different orientation of the protein upon binding in comparison to the native protein is proposed. Finally, the high fluorescence quenching observed in the titration experiments of the bioconjugates are discussed in terms of an amplification of the quenching efficiency by energy transfer on the self-assembled protein film and a severe effect of fluorofore interactions of the proteins attached to the nanoparticle surface

Diagnóstico financiero y análisis bursátil de Caterpillar Inc

Caterpillar es una empresa reconocida a nivel mundial, con gran trayectoria y con una historia que vale la pena conocer y estudiar; adicionalmente que esta entidad brindo grandes alternativas de innovación y ayuda durante la época de pandemia con los motores generadores de corriente eléctrica que eran indispensables para los respiradores utilizados en todos los hospitales y lugares de atención de enfermos; también es una empresa que ha estado presente en grandes acontecimientos a nivel mundial y cuyos productos han proporcionado crecimiento y expansión en construcciones y carreteras en todo el mundo. Teniendo en cuenta todas estas características, es bueno conocer como la empresa Caterpillar ha crecido y como maneja las finanzas, conociendo sus índices de apalancamiento y políticas de manejo tanto económicas como financieras, para lograr tener una perspectiva más profunda e identificar debilidades, destrezas, fortalezas y oportunidades que tiene la empresa y la mejor forma de utilizarlas en pro del crecimiento sustentable y sostenible con el tiempo. Para realizar esta labor es necesario conocer, estudiar e interpretar diferentes indicadores financieros que muestren propiamente el comportamiento de la entidad durante los años 2.020, 2.021 y 2.022 y lograr inferir conclusiones y recomendaciones que sirvan al crecimiento de la empresa.Caterpillar is a company recognized worldwide, with a long history and a history that is worth knowing and studying; Additionally, this entity provides great alternatives for innovation and help during the time of pandemic with the electric current generating motors that were essential for the respirators used in all hospitals and places caring for the sick; It is also a company that has been present in major events worldwide and whose products have provided growth and expansion in construction and roads around the world. Taking all these characteristics into account, it is good to know how the Caterpillar company has grown and how it manages finances, knowing its leverage ratios and management policies, both economic and financial, to achieve a deeper perspective and identify weaknesses, skills, strengths and opportunities that the company has and the best way to use them for sustainable and sustainable growth over time. To carry out this task, it is necessary to know study and interpret different financial indicators that properly show the behavior of the entity during the years 2020, 2021 and 2022 and to be able to infer conclusions and recommendations that serve the growth of the company

Surface Protection of Quaternary Gold Alloys by Thiol Self-Assembled Monolayers

This work deals with a physical and chemical surface characterization of quaternary 18K, 14K, and 9K gold alloys and pure polycrystalline gold substrates. Surface microstructure and composition are evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence spectroscopy. Corrosion resistance of 18K gold alloys is explored by potentiodynamic polarization showing the influence of the manufacturing process on materials fabricated as plates and wires. The research is also in the framework of one of the most common strategies on the modification of metallic surface properties, i.e., the building of self-assembled monolayers (SAM) from organic thiols. The metal affinity of the head group to produce the coating of the substrate by covalent binding is approached by using thiol compounds with different molecular structures and functional group chemistries exposed to an electrolyte solution. Therefore, a comparative study on the surface protection of a quaternary 18K gold alloy and pure gold substrates by SAMs of 6-mercaptopurine (6MP), 1-decanethiol (DT), and 11-mercaptoundecanoic acid (MUA) has been carried out. Surface modification and SAM organization are followed by cyclic voltammetry (CV), and the behavior of the double layer of the electrode–electrolyte interface is evaluated by electrochemical impedance spectroscopy (EIS). The study of these materials allows us to extract fundamental knowledge for its potential application in improving the bioactive properties of different jewelry pieces based on 18K gold alloys

Energy Properties of 22 Timber Species from Oaxaca, Mexico

The potential use of forest species as fuels depends on their energy quality. However, in rural communities in developing countries, fuelwood is still an energy source without any technical study evaluating its energetic characteristics. Therefore, this study aimed to analyze the energetic characteristics of 22 forest species from four communities in the state of Oaxaca, Mexico. The basic wood density, proximal analysis, and high heating value were evaluated. As a result of the analysis, the fuel number (FN) is proposed as a measure of the energy quality of biomass fuels in the form of firewood. FN considers the basic wood density, the fixed carbon, and the high heating value of each species. Wood basic density ranged from 0.472 g·cm-3 for Pinus pseudostrobus to 0.814 g·cm-3 for Dodonaea viscosa, fixed carbon ranged from 4.74% to 21.27% for Liquidambar styraciflua and Quercus rugosa, respectively, and high heating value from 18.33 MJ·kg-1 to 22.07 MJ·kg-1 for Liquidambar styraciflua and Pinus leiophylla, respectively. Classifying wood according to FN, in decreasing order, Quercus rugosa stands out as the best wood (66.97%), followed by Liquidambar styraciflua (39.52%). Regarding the fuel value index, the nine pine species showed the highest values (27.32 to 77.76). The FN provides a measure of the quality of biomass fuels in the form of firewood, and can be evaluated by easily measured variables

Tomato plant extract (Lycopersicon esculentum) obtained from agroindustrial byproducts and its antifungal activity against Fusarium spp.

Phytopathogenic fungi are a constant danger in the production of different crops around the world, especially in melons, since they can cause significant economic losses during the harvest, affecting the quality and shelf life. In recent years, producers have increasingly used chemical pesticides indiscriminately, causing environmental problems and damage to public health. For this reason, phytopathogenic fungi become more resistant. However, it is essential to guarantee the safety, quality, and shelf life of food after harvest, during transportation, storage and marketing. The presence of fungi in food can cause diseases transmitted through the production of toxins. Most producers depend on the discriminated use of chemical pesticides, which is a great challenge to guarantee food safety and sustainable agricultural production. To solve this problem, some extracts derived from tomato plants after harvest containing bioactive compounds have been implemented. These compounds can be natural antifungal agents as they contain phenols, flavonoids, and vitamins. Bioactive compounds emerge as a sustainable and safe opportunity in the search for new antifungal and antimicrobial agents. Therefore, the objective of this study was to determine the in vitro antifungal activity of whole tomato plant extracts on three phytopathogenic fungi. The research findings indicated that a concentration of 74.7 μg/mL of TPE resulted in a complete inhibition of mycelial growth in Fusarium oxysporum, Fusarium graminearum, and Fusarium verticillioides. Additionally, TPE exhibited both fungistatic and fungicidal effects on these Fusarium species, with a MIC50 of 30.7, 31.5, and 29.5, and a MFC of 82.4, 78.6, and 75.8 μg/mL, respectively. As a result, this study suggests that TPE can be considered as an environmentally friendly solution for extracting tomato plants, which can be applied to the surface of whole fruits or incorporated into semi-processed foods

La interdisciplina en el estudio de la forma urbana

Con esta edición se busca crear una plataforma analítica y de discusión sobre la importancia de la interdisciplina en el estudio de la forma de la ciudad. Por ello, en esta publicación se aborda el tema “Forma urbana e interdisciplina” a partir de cuatro ejes temáticos: Análisis y diagnósticos de la forma urbana; procesos históricos de la forma urbana; planes y proyectos urbanos e impactos en la forma urbana. Se espera que el material presentado cumpla con sus objetivos y que su lectura contribuya a ampliar el panorama de reflexión y discusión sobre el tema de la interdisciplina en el estudio de la forma urbana.Elizabeth Espinosa Dorantes; Christof Göbel; Salomón González Arrellano (sic), coordinadore

Sistema de evaluación institucional en enseñanza obligatoria en Iberoamérica

La presente aportación se focaliza, en este contexto, en la evaluación institucional externa (vinculada o no a la autoevaluación interna) y, por tanto, considera prioritariamente la manera como se evalúan los centros educativos como totalidad y no tanto alguno de sus aspectos (evaluación de la dirección, de los profesores, de los programas, etc.), que también pueden estar considerados. El énfasis también está en conocer la organización y desarrollo del sistema de evaluación. Recoge la visión de 43 especialistas de trece países iberoamericanos sobre las formas de entender y promover la evaluación institucional en sus centros educativos. Sus aportaciones, que deben contextualizarse en las particularidades educativas de sus países (ya presentadas en anteriores informes de la RedAGE), presentan los aspectos generales y normativos de la evaluación, las formas cómo se organiza, los efectos institucionales que tienen y algunas reflexiones, retos y propuestas para la mejora. Su orientación es claramente práctica y se vincula al encuentro anual que la RedAGE realizado los días 16 y 17 de mayo de 2016 en la ciudad de Leiria (Portugal). Allí, los representantes de las organizaciones miembro seleccionaron la temática por su interés actual (con clara vinculación a la mejora de los sistemas educativos y la acreditación institucional), consensuaron la estructura de las aportaciones y realizaron un intercambio de posibles ideas sobre la temática. Se cubre así y como en ocasiones anteriores el propósito fundamental de la RedAGE, como es el de fomentar el intercambio de experiencias, la promoción del conocimiento sobre administración y gestión educativa y la reflexión sobre la práctica de la gestión. La finalidad última sigue siendo la de mejorar el funcionamiento de los centros educativos (y, a través de ellos, de los sistemas educativos), procurando sean de calidad y un instrumento para el cambio profesional y social