19 research outputs found
Electrooxidation-Ozonation: A Synergistic Sustainable Wastewater Treatment Process
Advanced oxidation processes (AOPs) have shown to be very useful technologies for application in different wastewater treatment areas. These processes use the very strong oxidizing power of hydroxyl radicals to oxidize organic compounds to carbon dioxide and water. These procedures usually involve the use of O3, H2O2, Fenton’s reagent and electrolysis to generate the hydroxyl radicals. However, some recent investigations have found that the use of a coupled processes using O3/electrooxidation increases the effectiveness of the process and also could reduce the operating costs associated to the application of AOPs. In this chapter, there is a description of our work in the treatment of wastewater using an ozonation-electrooxidation combined process. The main parameters to control for having a successful application of such method are discussed. Several examples for different kinds of polluted water are addressed
Modelo de gestión integral para las Mipymes del sector Agropecuario del departamento del Quindío Colombia
Administrative and financial management is an important tool in business performance, for this reason it is essential to propose strategies, objectives and tactics that allow the promotion of a competitive culture for companies. In this sense, this article is the product of an investigation that was carried out in relation to the above mentioned field and in order to propose a management model for MSMEs in the agricultural sector of the Department of Quindío. The research method is descriptive, with a mixed approach, the sample involved 73 companies in the sector to which an instrument evaluated by expert judgment was applied. The results made it possible to propose a comprehensive management model that would facilitate organizational work, help its sustainability, growth and competitiveness in the market. The most relevant aspects of this research effort are presented below.La gestión administrativa y financiera es una herramienta importante en el desempeño empresarial, por tal razón es fundamental proponer estrategias, objetivos y tácticas que permitan el fomento de la cultura competitiva para las empresas. En tal sentido, el presente artículo es el producto de una investigación que se realizó en relación con el ámbito antes mencionado y con el fin de proponer un modelo de gestión para las Mipymes del sector agropecuario del departamento del Quindío. El método de investigación es descriptivo, con enfoque mixto, en la muestra participaron 73 empresas del sector a las que se le aplicó un instrumento evaluado por juicio de expertos. Los resultados permitieron proponer un modelo de gestión integral que permita facilitar el quehacer organizacional, ayudar a su sostenibilidad, crecimiento y competitividad en el mercado. A continuación, se presentan los aspectos más relevantes de este esfuerzo investigativo
Waste and Recycled Materials and their Impact on the Mechanical Properties of Construction Composite Materials
In a world increasingly fixated on the demands of sustainable development, too much attention has been focused on the widely used building materials, mainly on those tools and strategies for their reuse and those characteristics for considering them as environmental-friendly materials. Among the strategies are the following: (a) increased reliability on waste and recycled materials—such action will have to incorporate the substitution of recycled for virgin materials; (b) improved durability through reduction of materials needed for their replacement; and (c) improved mechanical properties, which reduces the use of raw materials. Extensive research and development activities in recycling composite materials have been conducted, and various technologies have been developed: (a) mechanical recycling, (b) thermal recycling, and (c) chemical recycling. However, gamma radiation is an innovative and clean technology, alternative to conventional recycling procedures. Gamma irradiation has proved to be an adequate tool for modifications of the physicochemical properties of polymers, through different effects: (a) scission, branching as well as cross-linking of polymer chains and (b) oxidative degradation. Moreover, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete. In this chapter, we show results of the effects of gamma irradiation on the physicochemical properties of waste and recycled materials and their reuse to enhance the properties of construction composite materials
Comprehensive management model for MSMEs in the agricultural sector of the department of Quindio Colombia
Administrative and financial management is an important tool in business performance, for this reason it is essential to propose strategies, objectives and tactics that allow the promotion of a competitive culture for companies. In this sense, this article is the product of an investigation that was carried out in relation to the above mentioned field and in order to propose a management model for MSMEs in the agricultural sector of the Department of Quindío. The research method is descriptive, with a mixed approach, the sample involved 73 companies in the sector to which an instrument evaluated by expert judgment was applied. The results made it possible to propose a comprehensive management model that would facilitate organizational work, help its sustainability, growth and competitiveness in the market. The most relevant aspects of this research effort are presented below.La gestión administrativa y financiera es una herramienta importante en el desempeño empresarial, por tal razón es fundamental proponer estrategias, objetivos y tácticas que permitan el fomento de la cultura competitiva para las empresas. En tal sentido, el presente artículo es el producto de una investigación que se realizó en relación con el ámbito antes mencionado y con el fin de proponer un modelo de gestión para las Mipymes del sector agropecuario del departamento del Quindío. El método de investigación es descriptivo, con enfoque mixto, en la muestra participaron 73 empresas del sector a las que se le aplicó un instrumento evaluado por juicio de expertos. Los resultados permitieron proponer un modelo de gestión integral que permita facilitar el quehacer organizacional, ayudar a su sostenibilidad, crecimiento y competitividad en el mercado. A continuación, se presentan los aspectos más relevantes de este esfuerzo investigativo
Química computacional en tu vida
Los expertos en química exponen algunos ejemplos de la utilidad de software especializado para representar gráficamente la composición molecular de diversos alimentos, como el chocolate, la leche y el café, de tal manera que se pueda establecer una relación de los efectos de estos en el organismo, tanto en el plano físico como mental.
 
1-(2-Chlorobenzyloxy)-3-[1,2,3]triazol-1-yl-propan-2-ol Derivatives: Synthesis, Characterization, and DFT-Based Descriptors Analysis
A novel series of 1-(2-chlorobenzyloxy)-3-[1,2,3]triazol-1-yl-propan-2-ol derivatives was designed and synthesized using copper catalyzed alkyne-azide cycloaddition in the key step. Theoretical investigation of molecular and electronic properties by means of global and local reactivity indexes of the synthetized compounds was carried out, using DFT (Density Functional Theory) at PBEPBE/6-31++G⁎⁎ level
[Efficacy and safety of atorvastatin in major cardiovascular events: Meta-analysis]
<p><strong>Abstract </strong></p><p><strong>Introduction:</strong> Atorvastatin has been used in the management of dyslipidemia and little is known about the efficacy and safety of high-dose atorvastatin administration for secondary prevention of Major Cardiovascular Events (MACE).</p><p>Objective: To evaluate the impact of high-dose atorvastatin on secondary prevention of MACE and adverse events.</p><p><strong>Material and methods:</strong> A systematic review and meta-analysis of Pubmed, Embase, Bireme and Cochrane Library Plus databases was performed, with a time scope from 1990 to July 2022. Six randomized clinical trials were included with a total of 29,333 patients who were treated with 80 mg, 10 mg or placebo doses of Atorvastatin where the main outcomes evaluated were Major Cardiovascular Events (MACE), mortality and treatment safety.</p><p><strong>Results:</strong> In the comparative study between the use of Atorvastatin 80 mg and other therapies, a relative risk (RR) of 0.8 (95%CI 0.69-0.92) was found, representing a 20% reduction in risk (RRR) and a number needed to treat (NNT) of 30-55. In the analysis of adverse effects, an RR of 2.37 (95% CI 0.86-6.53) and a number needed to harm (NNH) of 14-19 were observed. The use of 80 mg atorvastatin is associated with similar adverse events at lower doses.</p><p><strong>Conclusions:</strong> The use of atorvastatin 80 mg is effective in the secondary prevention of Major Cardiovascular Event (MACE). The drug has adverse events that should be taken into account in secondary prevention.</p><p><strong>Introducción: </strong>la atorvastatina ha sido usada en el manejo de la dislipidemia y se conoce poco sobre la eficacia y seguridad de la administración de atorvastatina en altas dosis para la prevención secundaria de eventos cardiovasculares mayores (MACE).</p><p><strong>Objetivo:</strong> evaluar el impacto de altas dosis de atorvastatina en la prevención secundaria de MACE y eventos adversos.</p><p><strong>Material y métodos:</strong> se realizó una revisión sistemática y un metaanálisis de las bases de datos <i>Pubmed</i>, <i>Embase</i>, <i>Bireme</i> y <i>Cochrane Library Plus</i>, con un alcance temporal de 1990 a julio de 2022. Se incluyeron seis ensayos clínicos aleatorios con un total de 29,333 pacientes que fueron tratados con dosis de 80 mg, 10 mg o placebo de Atorvastatina donde los resultados principales evaluados fueron los eventos cardiovasculares mayores (MACE), la mortalidad y la seguridad del tratamiento.</p><p><strong>Resultados:</strong> en el estudio comparativo entre el uso de Atorvastatina de 80 mg y otras terapias, se encontró un riesgo relativo (RR) de 0.8 (IC95%: 0.69-0.92), lo que representa una reducción del 20% en el riesgo (RRR) y un número necesario a tratar (NNT) de 30 a 55. En el análisis de los efectos adversos, se observó un RR de 2.37 (IC95%: 0.86-6.53) y un número necesario a dañar (NNH) de 14 a 19. El uso de atorvastatina de 80 mg se asocia con eventos adversos similares a dosis menores.</p><p><strong>Conclusiones:</strong> el uso de atorvastatina de 80 mg es efectivo en la prevención secundaria de evento cardiovascular mayor (MACE). El medicamento tiene eventos adversos que deben de tomarse en cuenta en la prevención secundaria.</p>
Waste and recycled materials and their impact on the mechanical properties of Construction Materials
In a world increasingly fixated on the demands of sustainable development, too much attention has been focused on the widely used building materials, mainly on those tools and strategies for their reuse and those characteristics for considering them as environmental-friendly materials. Among the strategies are the following: (a) increased reliability on waste and recycled materials—such action will have to incorporate the substitution of recycled for virgin materials; (b) improved durability through reduction of materials needed for their replacement; and (c) improved mechanical properties, which reduces the use of raw materials. Extensive research and development activities in recycling composite materials have been conducted, and various technologies have been developed: (a) mechanical recycling, (b) thermal recycling, and (c) chemical recycling. However, gamma radiation is an innovative and clean technology, alternative to conventional recycling procedures. Gamma irradiation has proved to be an adequate tool for modifications of the physicochemical properties of polymers, through different effects: (a) scission, branching as well as cross-linking of polymer chains and (b) oxidative degradation. Moreover, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete. In this chapter, we show results of the effects of gamma irradiation on the physicochemical properties of waste and recycled materials and their reuse to enhance the properties of construction composite materials