Mezclas de cera y bentonita para el desarrollo de arcilla industrial de prototipado: resultados preliminares

The automotive design process and the materials in the automotive industry in recent years has caused great interest to the industrial and academic sector. In this study was to evaluate the effect of the amount of bentonite on the thermal and rheological properties of the compound bentonite / paraffin wax. Two bentonite ratios were used: paraffin wax (40:60 and 30:70). The paraffin was characterized by Fourier transform infrared spectroscopy (FTIR), the bentonite was characterized by means of x-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray fluorescence (XRF). The bentonite/paraffine wax composite was characterized by differential-scanning calorimetry (DSC) and rheology. The sample that contains a higher amount of bentonite shows a lower latent heat, and this could cause a greater heat transfer. Finally, the sample that has a lower amount of bentonite evidenced a lower viscosity, and it could be related to a lower interaction between the particles. The sample S1 due to its lower latent heat compared to S2 could represent an interesting alternative to develop prototypingclays. since these materials are characterized by their low working temperatures and easy malleability. Keywords: automotive, prototyping, latent heat, bentonite, paraffin. References [1]X. Ferràs-Hernández, E. Tarrats-Pons, and N. Arimany-Serrat, “Disruption in the automotive industry: A Cambrian moment,” Bus. Horiz., vol. 60, no. 6, pp.855–863, 2017, doi: 10.1016/j.bushor.2017.07.011. [2]O. Heneric, G. Licht, S. Lutz, and W. Urban, “The Europerean Automotive Industry in a Global Context,” Eur. Automot. Ind. Move, pp. 5–44, 2005, doi: 10.1007/3-7908-1644-2_2. [3]S. I.-N. Delhi, “Automotive Revolution & Perspective Towards 2030,” Auto Tech Rev., vol. 5, no. 4, pp. 20–25, Apr. 2016, doi: 10.1365/s40112-016-1117-8.[4]M. Tovey, J. Owen, and P. Street, “in Automotive Design,” vol. 21, pp. 569–588, 2000. [5]Yasusato Yamada, Clay modeling : techniques for giving three-dimensional form to idea. 1997. [6]H. Murray, “Industrial clays case study,” Mining, Miner. Sustain. Dev., vol. 1, no. 64, pp. 1–9, 2002, [Online]. Available: http://www.whitemudresources.com/public/Hayn Murray Clays Case Study.pdf%0Ahttp://whitemudresources.com/public/Hayn Murray ClaysCase Study.pdf. [7]Transparency Market Research, “Industrial Clay Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2016 - 2024,” New york, 2016.[8]J. Murphy, Additives for Plastics Handbook. Elsevier, 2001. [9]Y. Hong, J. J. Cooper-White, M. E. Mackay, C. J. Hawker, E. Malmström, and N. Rehnberg, “A novel processing aid for polymer extrusion: Rheology and processing of polyethylene and hyperbranched polymer blends,” J. Rheol. (N. Y. N. Y)., vol. 43, no. 3, pp. 781–793, 1999, doi: 10.1122/1.550999. [10]D. P. Rawski, P. Edwards, and U. States, “Pulp and Paper : Non fi brous Components,” no. January, pp.1–4, 2017, doi: 10.1016/B978-0-12-803581-8.10289-9. [11]J. Speight, “Instability and incompatibility of tight oil and shale oil,” Shale Oil Gas Prod. Process., pp. 915–942, 2020, doi: 10.1016/b978-0-12-813315-6.00017-8. [12]T. P. Brown, L. Rushton, M. A. Mugglestone, and D. F. Meechan, “Health effects of a sulphur dioxide air pollution episode,” vol. 25, no. 4, pp. 369–371, 2003,doi: 10.1093/pubmed/fdg083. [13]R. Chihi, I. Blidi, M. Trabelsi-Ayadi, and F. Ayari, “Elaboration and characterization of a low-cost porous ceramic support from natural Tunisian bentonite clay,” Comptes Rendus Chim., vol. 22, no. 2–3, pp. 188–197, 2019, doi: 10.1016/j.crci.2018.12.002. [14]Z. Yi, W. Xiaopeng, and L. I. Dongxu, “Prepartion of organophilic bentonite / paraffin composite phase change energy storage material with melting intercalation method,” pp. 126–131, 2011, doi: 10.4028/www.scientific.net/AMR.284-286.126. [15]I. Krupa and A. S. Luyt, “Thermal and mechanical properties of extruded LLDPE / wax blends,” vol. 73, pp. 157–161, 2001. [16]A. Saleem, L. Frormann, J. Koltermann, and C. Reichelt, “Fabrication and Processing of Polypropylene - Paraffin Compounds with Enhanced Thermal andProcessing Properties : Impact Penetration and Thermal Characterization,” vol. 40164, pp. 1–9, 2014, doi:10.1002/app.40164. [17]M. Mu, P. A. M. Basheer, W. Sha, Y. Bai, and T. Mcnally, “Shape stabilised phase change materials based on a high melt viscosity HDPE and paraffin waxes,”Appl. Energy, vol. 162, pp. 68–82, 2016, doi: 10.1016/j.apenergy.2015.10.030. [18]M. Tovey, “Intuitive and objective processes in automotive design,” Des. Stud., vol. 13, no. 1, pp. 23–41, 1992, doi: 10.1016/0142-694X(92)80003-H. [19]J. Verlinden, A. Kooijman, E. Edelenbos, and C. Go, “Investigation on the use of illuminated clay in automotive styling,” 6th Int. Conf. Comput. Ind. Des.Concept. Des. (CAID&CD), Delft, NETHERLANDS, pp. 514–519, 2005. [20]N. W. Muhamad Bustaman and M. S. Abu Mansor, “A Study on CAD/CAM Application in CNC Milling Using Industrial Clay,” Appl. Mech. Mater., vol. 761, pp. 32–36, 2015, doi: 10.4028/www.scientific.net/AMM.761.32. [21]K. Shimokawa, Japan and the global automotive industry. 2010. [22]A. Bucio, R. Moreno tovar, L. Bucio, J. Espinosadávila, and F. Anguebes franceschi, “Characterization of beeswax, candelilla wax and paraffin wax for coatingcheeses,” Coatings, vol. 11, no. 3, pp. 1–18, 2021, doi: 10.3390/coatings11030261. [23]F. Valentini, A. Dorigato, A. Pegoretti, M. Tomasi, G. D. Sorarù, and M. Biesuz, “Si3N4 nanofelts/paraffin composites as novel thermal energy storage architecture,” J. Mater. Sci., vol. 56, no. 2, pp. 1537–1550, 2021, doi: 10.1007/s10853-020-05247-5. [24]F. Paquin, J. Rivnay, A. Salleo, N. Stingelin, and C. Silva, “Multi-phase semicrystalline microstructures drive exciton dissociation in neat plastic semiconductors,” J. Mater. Chem. C, vol. 3, pp. 10715–10722, 2015, doi: 10.1039/b000000x. [25]R. S. Hebbar, A. M. Isloor, B. Prabhu, Inamuddin, A. M. Asiri, and A. F. Ismail, “Removal of metal ions and humic acids through polyetherimide membranewith grafted bentonite clay,” Sci. Rep., vol. 8, no. 1, 2018, doi: 10.1038/s41598-018-22837-1. [26]S. Betancourt-Parra, M. A. Domínguez-Ortiz, and M. Martínez-Tejada, “Colombian clays binary mixtures: Physical changes due to thermal treatments,” DYNA, vol. 87, no. 212, pp. 73–79, 2020, doi: 10.15446/dyna.v87n212.82285. [27]A. M. Rabie, E. A. Mohammed, and N. A. Negm, “Feasibility of modified bentonite as acidic heterogeneous catalyst in low temperature catalytic crackingprocess of biofuel production from nonedible vegetable oils,” J. Mol. Liq., vol. 254, no. 2018, pp. 260–266, 2018, doi: 10.1016/j.molliq.2018.01.110. [28]A. Kadeche et al., “Preparation, characterization and application of Fe-pillared bentonite to the removal of Coomassie blue dye from aqueous solutions,” Res. Chem. Intermed., vol. 46, no. 11, pp. 4985–5008, 2020, doi: 10.1007/s11164-020-04236-2. [29]C. I. R. De Oliveira, M. C. G. Rocha, A. L. N. DaSilva, and L. C. Bertolino, “Characterization of bentonite clays from Cubati, Paraíba Northeast of Brazil,” Ceramica, vol. 62, no. 363, pp. 272–277, 2016, doi:10.1590/0366-69132016623631970. [30]I. Z. Hager, Y. S. Rammah, H. A. Othman, E. M. Ibrahim, S. F. Hassan, and F. H. Sallam, “Nano-structured natural bentonite clay coated by polyvinyl alcohol polymer for gamma rays attenuation,” J. Theor. Appl. Phys., vol. 13, no. 2, pp. 141–153, 2019, doi: 10.1007/ s40094-019-0332-5. [31]A. Tebeje, Z. Worku, T. T. I. Nkambule, and J. Fito, “Adsorption of chemical oxygen demand from textile industrial wastewater through locally prepared bentonite adsorbent,” Int. J. Environ. Sci. Technol., no. 0123456789, 2021, doi: 10.1007/s13762-021-03230-4. [32]F. E. Özgüven, A. D. Pekdemir, M. Önal, and Y. Sarıkaya, “Characterization of a bentonite and its permanent aqueous suspension,” J. Turkish Chem. Soc.Sect. A Chem., vol. 7, no. 1, pp. 11–18, 2019, doi: 10.18596/jotcsa.535937. [33]S. Tao, S. Wei, and Y. Yulan, “Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage,” J. Mater. Civ. Eng., vol. 27, no. 4, p. 04014156, 2015, doi: 10.1061/(asce)mt.1943-5533.0001089. [34]M. Li, Z. Wu, H. Kao, and J. Tan, “Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material,” Energy Convers. Manag., vol. 52, no. 11, pp. 3275–3281, 2011, doi: 10.1016/j.enconman.2011.05.015. [35]S. M. Hosseini, E. Ghasemi, A. Fazlali, and D. E. Henneke, “The effect of nanoparticle concentration on the rheological properties of paraffin-based Co3O4 ferrofluids,” J. Nanoparticle Res., vol. 14, no. 7, 2012, doi: 10.1007/s11051-012-0858-9.El proceso de diseño automotriz y los materiales en la industria automotriz pen los últimos años ha despertado un gran interés en el sector industrial y académico. En este estudio se evaluó el efecto de la cantidad de bentonita sobre las propiedades térmicas y reológicas del compuesto bentonita/ cera de parafina. Se utilizaron dos proporciones de bentonita: cera de parafina (40:60 y 30:70). La parafina se caracterizó por espectroscopia infrarroja por transformada de Fourier (FTIR), la bentonita se caracterizó mediante difracción de rayos X (XRD), análisis termogravimétrico (TGA), fluorescencia de rayos X (XRF). El compuesto de cera de bentonita / parafina se caracterizó por calorimetría de barrido diferencial (DSC) y reología. La muestra que contiene una mayor cantidad de bentonita presenta un menor calor latente, y esto podría provocar una mayor transferencia de calor. Finalmente, la muestra que tiene menor cantidad de bentonita evidenció una menor viscosidad, y podría estar relacionado con una menor interacción entre las partículas. La muestra S1 debido a su menor calor latente en comparación con S2 podría representar una alternativa interesante para desarrollar arcillas de prototipado. Ya que estos materiales S3 caracterizan por sus bajas temperaturas de trabajo y fácil maleabilidad. Palabras clave: automóvil, prototipado, reología, bentonita, parafina. Referencias [1]X. Ferràs-Hernández, E. Tarrats-Pons, y N. Arimany-Serrat, “Disruption in the automotive industry: A Cambrian moment,” Bus. Horiz., vol. 60, no. 6, pp.855–863, 2017, doi: 10.1016/j.bushor.2017.07.011. [2]O. Heneric, G. Licht, S. Lutz, y W. Urban, “The Europerean Automotive Industry in a Global Context,” Eur. Automot. Ind. Move, pp. 5–44, 2005, doi: 10.1007/3-7908-1644-2_2. [3]S. I.-N. Delhi, “Automotive Revolution & Perspective Towards 2030,” Auto Tech Rev., vol. 5, no. 4, pp. 20–25, Apr. 2016, doi: 10.1365/s40112-016-1117-8. [4]M. Tovey, J. Owen, y P. Street, “in Automotive Design,” vol. 21, pp. 569–588, 2000. [5]Yasusato Yamada, Clay modeling : techniques for giving three-dimensional form to idea. 1997. [6]H. Murray, “Industrial clays case study,” Mining, Miner. Sustain. Dev., vol. 1, no. 64, pp. 1–9, 2002, [En línea]. Disponible en: http://www.whitemudresources.com/public/Hayn Murray Clays Case Study.pdf%0Ahttp://whitemudresources.com/public/Hayn Murray ClaysCase Study.pdf. [7]Transparency Market Research, “Industrial Clay Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2016 - 2024,” New york, 2016.[8]J. Murphy, Additives for Plastics Handbook. Elsevier, 2001. [9]Y. Hong, J. J. Cooper-White, M. E. Mackay, C. J. Hawker, E. Malmström, y N. Rehnberg, “A novel processing aid for polymer extrusion: Rheology and processing of polyethylene and hyperbranched polymer blends,” J. Rheol. (N. Y. N. Y)., vol. 43, no. 3, pp. 781–793, 1999, doi: 10.1122/1.550999. [10]D. P. Rawski, P. Edwards, y U. States, “Pulp and Paper : Non fi brous Components,” no. January, pp.1–4, 2017, doi: 10.1016/B978-0-12-803581-8.10289-9. [11]J. Speight, “Instability and incompatibility of tight oil and shale oil,” Shale Oil Gas Prod. Process., pp. 915–942, 2020, doi: 10.1016/b978-0-12-813315-6.00017-8. [12]T. P. Brown, L. Rushton, M. A. Mugglestone, y D. F. Meechan, “Health effects of a sulphur dioxide air pollution episode,” vol. 25, no. 4, pp. 369–371, 2003,doi: 10.1093/pubmed/fdg083. [13]R. Chihi, I. Blidi, M. Trabelsi-Ayadi, y F. Ayari, “Elaboration and characterization of a low-cost porous ceramic support from natural Tunisian bentonite clay,” Comptes Rendus Chim., vol. 22, no. 2–3, pp. 188–197, 2019, doi: 10.1016/j.crci.2018.12.002. [14]Z. Yi, W. Xiaopeng, y L. I. Dongxu, “Prepartion of organophilic bentonite / paraffin composite phase change energy storage material with melting intercalation method,” pp. 126–131, 2011, doi: 10.4028/www.scientific.net/AMR.284-286.126. [15]I. Krupa y A. S. Luyt, “Thermal and mechanical properties of extruded LLDPE / wax blends,” vol. 73, pp. 157–161, 2001. [16]A. Saleem, L. Frormann, J. Koltermann, y C. Reichelt, “Fabrication and Processing of Polypropylene - Paraffin Compounds with Enhanced Thermal andProcessing Properties : Impact Penetration and Thermal Characterization,” vol. 40164, pp. 1–9, 2014, doi:10.1002/app.40164. [17]M. Mu, P. A. M. Basheer, W. Sha, Y. Bai, y T. Mcnally, “Shape stabilised phase change materials based on a high melt viscosity HDPE and paraffin waxes,”Appl. Energy, vol. 162, pp. 68–82, 2016, doi: 10.1016/j.apenergy.2015.10.030. [18]M. Tovey, “Intuitive and objective processes in automotive design,” Des. Stud., vol. 13, no. 1, pp. 23–41, 1992, doi: 10.1016/0142-694X(92)80003-H. [19]J. Verlinden, A. Kooijman, E. Edelenbos, y C. Go, “Investigation on the use of illuminated clay in automotive styling,” 6th Int. Conf. Comput. Ind. Des.Concept. Des. (CAID&CD), Delft, NETHERLANDS, pp. 514–519, 2005. [20]N. W. Muhamad Bustaman y M. S. Abu Mansor, “A Study on CAD/CAM Application in CNC Milling Using Industrial Clay,” Appl. Mech. Mater., vol. 761, pp. 32–36, 2015, doi: 10.4028/www.scientific.net/AMM.761.32. [21]K. Shimokawa, Japan and the global automotive industry. 2010. [22]A. Bucio, R. Moreno tovar, L. Bucio, J. Espinosadávila, y F. Anguebes franceschi, “Characterization of beeswax, candelilla wax and paraffin wax for coatingcheeses,” Coatings, vol. 11, no. 3, pp. 1–18, 2021, doi: 10.3390/coatings11030261. [23]F. Valentini, A. Dorigato, A. Pegoretti, M. Tomasi, G. D. Sorarù, y M. Biesuz, “Si3N4 nanofelts/paraffin composites as novel thermal energy storage architecture,” J. Mater. Sci., vol. 56, no. 2, pp. 1537–1550, 2021, doi: 10.1007/s10853-020-05247-5. [24]F. Paquin, J. Rivnay, A. Salleo, N. Stingelin, y C. Silva, “Multi-phase semicrystalline microstructures drive exciton dissociation in neat plastic semiconductors,” J. Mater. Chem. C, vol. 3, pp. 10715–10722, 2015, doi: 10.1039/b000000x. [25]R. S. Hebbar, A. M. Isloor, B. Prabhu, Inamuddin, A. M. Asiri, y A. F. Ismail, “Removal of metal ions and humic acids through polyetherimide membranewith grafted bentonite clay,” Sci. Rep., vol. 8, no. 1, 2018, doi: 10.1038/s41598-018-22837-1. [26]S. Betancourt-Parra, M. A. Domínguez-Ortiz, y M. Martínez-Tejada, “Colombian clays binary mixtures: Physical changes due to thermal treatments,” DYNA, vol. 87, no. 212, pp. 73–79, 2020, doi: 10.15446/dyna.v87n212.82285. [27]A. M. Rabie, E. A. Mohammed, y N. A. Negm, “Feasibility of modified bentonite as acidic heterogeneous catalyst in low temperature catalytic crackingprocess of biofuel production from nonedible vegetable oils,” J. Mol. Liq., vol. 254, no. 2018, pp. 260–266, 2018, doi: 10.1016/j.molliq.2018.01.110. [28]A. Kadeche et al., “Preparation, characterization and application of Fe-pillared bentonite to the removal of Coomassie blue dye from aqueous solutions,” Res. Chem. Intermed., vol. 46, no. 11, pp. 4985–5008, 2020, doi: 10.1007/s11164-020-04236-2. [29]C. I. R. De Oliveira, M. C. G. Rocha, A. L. N. DaSilva, y L. C. Bertolino, “Characterization of bentonite clays from Cubati, Paraíba Northeast of Brazil,” Ceramica, vol. 62, no. 363, pp. 272–277, 2016, doi:10.1590/0366-69132016623631970. [30]I. Z. Hager, Y. S. Rammah, H. A. Othman, E. M. Ibrahim, S. F. Hassan, y F. H. Sallam, “Nano-structured natural bentonite clay coated by polyvinyl alcohol polymer for gamma rays attenuation,” J. Theor. Appl. Phys., vol. 13, no. 2, pp. 141–153, 2019, doi: 10.1007/ s40094-019-0332-5. [31]A. Tebeje, Z. Worku, T. T. I. Nkambule, y J. Fito, “Adsorption of chemical oxygen demand from textile industrial wastewater through locally prepared bentonite adsorbent,” Int. J. Environ. Sci. Technol., no. 0123456789, 2021, doi: 10.1007/s13762-021-03230-4. [32]F. E. Özgüven, A. D. Pekdemir, M. Önal, e Y. Sarıkaya, “Characterization of a bentonite and its permanent aqueous suspension,” J. Turkish Chem. Soc.Sect. A Chem., vol. 7, no. 1, pp. 11–18, 2019, doi: 10.18596/jotcsa.535937. [33]S. Tao, S. Wei, e Y. Yulan, “Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage,” J. Mater. Civ. Eng., vol. 27, no. 4, p. 04014156, 2015, doi: 10.1061/(asce)mt.1943-5533.0001089. [34]M. Li, Z. Wu, H. Kao, y J. Tan, “Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material,” Energy Convers. Manag., vol. 52, no. 11, pp. 3275–3281, 2011, doi: 10.1016/j.enconman.2011.05.015. [35]S. M. Hosseini, E. Ghasemi, A. Fazlali, y D. E. Henneke, “The effect of nanoparticle concentration on the rheological properties of paraffin-based Co3O4 ferrofluids,” J. Nanoparticle Res., vol. 14, no. 7, 2012, doi: 10.1007/s11051-012-0858-9

Sistema administrativo modular para restaurantes

No aplicaLos restaurantes enfrentan dificultades para analizar sus costos debido a la falta de un sistema de información adecuado. Esto puede hacer que sea difícil para los propietarios y gerentes de restaurantes identificar los costos de los productos y servicios y tomar decisiones informadas sobre los precios y la estrategia de negocios. El manejo de inventario también se ve afectado por la falta de un sistema de información. Sin un sistema de seguimiento de inventario, los restaurantes pueden tener dificultades para saber qué productos están disponibles, cuánto se está gastando en ellos y cuándo es necesario reponerlos. Esto puede llevar a una sobrecarga de trabajo para los empleados y a un aumento de los costos de almacenamiento. La falta de un sistema de información también puede dificultar la toma de decisiones en cuanto a la estrategia de negocio del restaurante, ya que no se cuenta con información precisa y actualizada sobre los costos y los inventarios. Es importante para los restaurantes tener un sistema de información adecuado para poder analizar sus costos y manejar sus inventarios de manera eficiente. Esto puede incluir el uso de herramientas de software de gestión de inventarios y programas de contabilidad para ayudar a los propietarios y gerentes de restaurantes a tomar decisiones informadas sobre los precios y la estrategia de negocios. En la actualidad se tiene diversos tipos de restaurantes, tenemos restaurantes de proporciones pequeñas de entrada y salida de usuarios, sin mesas para la atención, hasta restaurantes de grandes magnitudes, pensando en esto se ha logrado dividir un sistema administrativo en módulos, la definición de modulo nos muestra que es un componente de un software completo que es desarrollado de forma independiente para una función específica, el sistema que se propone en este caso, son módulo de ventas, módulo de inventario, módulo de compras, módulo de informes, todo pensando en la necesidad diferencial de cada lugar. En resumen, se puede afirmar que la falta de un sistema de información adecuado en los restaurantes puede generar dificultades en el análisis de costos y en el manejo de inventarios, lo que se traduce en una mala toma de decisiones y en un aumento de los costos de almacenamiento y trabajo.Restaurants face difficulties in analyzing their costs due to the lack of an adequate information system. This can make it difficult for restaurant owners and managers to identify the costs of products and services and make informed decisions about pricing and business strategy. Inventory management is also affected by the lack of an information system. Without an inventory tracking system, restaurants can have a hard time knowing what products are in stock, how much is being spent on them, and when they need to be restocked. This can lead to overwork for employees and increased storage costs. The lack of an information system can also make it difficult to make decisions regarding the restaurant's business strategy, since there is no accurate and updated information on costs and inventories. It is important for restaurants to have an adequate information system to be able to analyze their costs and manage their inventories efficiently. This may include the use of inventory management software tools and accounting programs to help restaurant owners and managers make informed decisions about pricing and business strategy. At present there are various types of restaurants, we have restaurants of small proportions of entrance and exit of users, without tables for attention, even restaurants of large magnitudes, thinking about this, it has been possible to divide an administrative system into modules, the definition of module shows us that it is a component of a complete software that is developed independently for a specific function, the system that is proposed in this case, are sales module, inventory module, purchasing module, reporting module, all thinking in the differential need of each place. In summary, it can be stated that the lack of an adequate information system in restaurants can generate difficulties in cost analysis and inventory management, which translates into poor decision making and increased costs. storage and work

Análisis de las variables críticas de un sistema productivo a través de la Dinámica de Sistemas

Un sistema productivo que presente falencias en la administración de sus procesos de almacenamiento de inventario y materiales puede ser representado con la metodología de Dinámica de Sistemas, involucrando las variables críticas del mismo y generando un análisis de sensibilidad de acuerdo con diferentes alternativas de decisión, que busquen mejorar sus condiciones de productividad actuales. El artículo expone el resultado de un trabajo de investigación propuesto para una microempresa que presenta bajos índices de productividad total, y, a través de un modelo de simulación se pueden analizar diferentes propuestas de decisión para  su mejoramiento

Aptitud de cosecha de agua lluvia para cultivo de piña del municipio de Lebrija - Santander

En el municipio de Lebrija (Santander) se presenta un déficit hídrico en los cultivos de piña, por lo que se muestra cómo a través de la modelación y los geoprocesos en un SIG se puede organizar la información ambiental, edáfica y climática del municipio para determinar la aptitud del municipio para implementar la estrategia de cosechar agua lluvia como respuesta a la problemática planteada.In the municipality of Lebrija (Santander) there is a water deficit in pineapple crops, which is why it is shown how, through modeling and geoprocessing in a GIS, the environmental, edaphic and climatic information of the municipality can be organized to determine the aptitude of the municipality to implement the strategy of harvesting rainwater as a response to the problem raised

Análisis de las variables críticas de un sistema productivo a través de la Dinámica de Sistemas

Un sistema productivo que presente falencias en la administración de sus procesos de almacenamiento de inventario y materiales puede ser representado con la metodología de Dinámica de Sistemas, involucrando las variables críticas del mismo y generando un análisis de sensibilidad de acuerdo con diferentes alternativas de decisión, que busquen mejorar sus condiciones de productividad actuales. El artículo expone el resultado de un trabajo de investigación propuesto para una microempresa que presenta bajos índices de productividad total, y, a través de un modelo de simulación se pueden analizar diferentes propuestas de decisión para  su mejoramiento

Total gastrectomy for stomach cancer at Hospital Universitario San Jose, Popayán. Retrospective cohort study of 16 years

Objective: To describe clinical, histological outcomes and postoperative surgical complications of patients who were under total gastrectomy for gastric cancer at the Hospital Universitario San José (HUSJ) of Popayan in the period from 1990 to 2006. Methods: Retrospective cohort study. We included patients with history of total gastrectomy secondary to gastric cancer. Patients were characterized clinically and demographically according preoperative state. Data related to the surgical technique, diagnosis and clinical TNM stage were described. Early mortality (less than thirty days), occurrence of fistula or abdominal sepsis during hospitalization and length of hospital stay was calculated. The length of hospital stay until discharge was analyzed graphically. Results: During the study period 69 procedures were performed. 73% of patients were male and the mean age was 62 years. 97% of the subjects (60 patients) had advanced gastric cancer, 75% had adenocarcinoma of intestinal type and 15% of diffuse type. Postoperative complications occurred in 20.2%, including requirement of surgical re-intervention (10%), abdominal fistula (7.2%) and abdominal sepsis (3%). The 30-day mortality was 4.3% (95% CI (1.1 to 11.3)). Discussion: Demographic and clinical patterns of the patients studied do not differ from those reported in literature worldwide. Frequencies of complications and mortality found in this study are consistent with those from larger studies. Given the lateness of diagnosis, actions of prevention and screening for early detection of gastric cancer should be carried out in our country to increase the chances of curative treatment

Gastrectomía total por cáncer gástrico en el Hospital Universitario San José de Popayán. Cohorte retrospectiva de 16 años.

Objective: To describe clinical, histological outcomes and postoperative surgical complications of patients who were under total gastrectomy for gastric cancer at the Hospital Universitario San José (HUSJ) of Popayan in the period from 1990 to 2006. Methods: Retrospective cohort study. We included patients with history of total gastrectomy secondary to gastric cancer. Patients were characterized clinically and demographically according preoperative state. Data related to the surgical technique, diagnosis and clinical TNM stage were described. Early mortality (less than thirty days), occurrence of fistula or abdominal sepsis during hospitalization and length of hospital stay was calculated. The length of hospital stay until discharge was analyzed graphically. Results: During the study period 69 procedures were performed. 73% of patients were male and the mean age was 62 years. 97% of the subjects (60 patients) had advanced gastric cancer, 75% had adenocarcinoma of intestinal type and 15% of diffuse type. Postoperative complications occurred in 20.2%, including requirement of surgical re-intervention (10%), abdominal fistula (7.2%) and abdominal sepsis (3%). The 30-day mortality was 4.3% (95% CI (1.1 to 11.3)). Discussion: Demographic and clinical patterns of the patients studied do not differ from those reported in literature worldwide. Frequencies of complications and mortality found in this study are consistent with those from larger studies. Given the lateness of diagnosis, actions of prevention and screening for early detection of gastric cancer should be carried out in our country to increase the chances of curative treatment.Objetivo: Describir los desenlaces clínicos, histológicos y las complicaciones quirúrgicas posoperatorias de pacientes a los que se les practico gastrectomía total por cáncer gástrico en el Hospital Universitario San José (HUSJ) de Popayán en el periodo de 1990 a 2006. Metodología: Estudiode cohorte retrospectiva. Se incluyeron pacientes con antecedente de gastrectomía total en el contexto de cáncer gástrico. Los pacientes fueron caracterizados demográfica y clínicamente de acuerdo su estado preoperatorio. Se describieron datos relacionados con la técnica quirúrgica utilizada, diagnóstico y estadio clínico TNM. Se calculó la mortalidad temprana (inferior a treinta días), desarrollo de fístula durante la hospitalización, desarrollo de sepsis de origen abdominal y tiempo total de estancia hospitalaria. Se analizó gráficamente el tiempo de estancia hasta el egreso hospitalario. Resultados: En el periodo en estudio se practicaron 69 gastrectomías totales. El 73% de los pacientes fueron hombres y la media de edad fue de 62 años. El 97% de los sujetos (60 pacientes) cursaban con cáncer gástrico avanzado, 75% tenían adenocarcinoma de tipo intestinal y 15% de tipo difuso. Las complicaciones posquirúrgicas ocurrieron en 20,2%, entre ellas, requerimiento de re-intervención quirúrgica (10%), fístula abdominal (7,2%) y sepsis abdominal (3%). La mortalidad a 30 días fue de 4,3% (IC95% (1,1-11,3). Discusión: Los resultados socios demográficos y clínicos de los pacientes estudiados no difieren de los reportados en literatura mundial. Las frecuencias de complicaciones y mortalidad encontradas en este estudio están acordes a las de estudios de mayor magnitud. Ante lo tardío del diagnóstico, acciones de prevención y tamizaje para la detección temprana del cáncer gástrico deben ser efectuadas en nuestro medio para incrementar las probabilidades de tratamiento curativo

Etiología y caracterización epidemiológica del síndrome febril no palúdico en tres municipios del Urabá antioqueño, Colombia

Introduction: Urabá, a region on the northern coast of Colombia, is endemic to several acute febrile illnesses of infectious origin; however, only patients with malaria may have access to quick and effective diagnosis. For this reason, many non-malarial febrile patients go without a clear etiologic diagnosis.Aim: To establish the etiology and clinical signs of acute febrile non-malaria syndromes and explore some of the likely risk factors in patients originating in the municipalities of Necocli, Turbo and Apartado who exhibit these symptoms.Materials and methods: We obtained acute and convalescent sera from 220 non-malarial febrile patients from the rural and urban zones of Necocli, Turbo and Apartado during 2007 and 2008. Serologic tests for dengue (IgM by ELISA), leptospirosis (IgM and IgG by IFA), rickettsiosis (IgG by IFI), hanta and arenavirus (IgG by ELISA) were performed.Results: We found that the frequency of infection for dengue, leptospirosis, rickettsiosis and arenavirus, was 37.3%; 14.1%; 2.7% and 0.5%, respectively. There were 12 co-infection cases of leptospirosis-dengue and one of leptospirosis-rickettsiosis-dengue. Male gender and relative humidity were considered risk factors for dengue, and the beginning of clinical signs in February of 2008 was associated with the infection of dengue and leptospirosis.Conclusion: This study confirms previous records that underline the importance of Rickettsia spp,dengue virus and Leptospira spp as causal agents of febrile syndrome in this region of Colombia. doi: http://dx.doi.org/10.7705/biomedica.v33i0.734Introducción. La región de Urabá es endémica para varias enfermedades febriles agudas de origen infeccioso. Sin embargo, solo los pacientes con malaria pueden acceder a un diagnóstico oportuno y rápido, motivo por el cual muchos síndromes febriles no palúdicos quedan sin diagnóstico etiológico claro.Objetivo. Establecer la etiología, describir las manifestaciones clínicas y explorar algunos posibles factores de riesgo relacionados con los síndromes febriles agudos no palúdicos en pacientes procedentes de los municipios de Necoclí, Turbo y Apartadó.Materiales y métodos. Se tomaron muestras de suero en fase aguda y de convalecencia de 220 pacientes febriles negativos para malaria, provenientes de zonas rurales y urbanas de Necoclí, Turbo y Apartadó en los años 2007 y 2008. Se practicaron pruebas para diagnóstico de dengue (detecciónde anticuerpos IgM por ELISA), leptospirosis (detección de anticuerpos IgM e IgG por IFI), rickettsiosis (detección de anticuerpos IgG por IFI), hantavirus y arenavirus (detección de anticuerpos IgG porELISA).Resultados. Se encontraron frecuencias de dengue, leptospirosis, rickettsiosis y arenavirus de 37,3 %,14,1 %, 2,7 % y 0,5 %, respectivamente. Se presentaron 12 casos de coinfección de leptospirosis-denguey uno de leptospirosis-rickettsiosis-dengue. El sexo masculino y la humedad relativa media,fueron factores de riesgo para dengue. El inicio de signos clínicos en febrero de 2008, se asoció tanto con la infección por dengue como por leptospirosis.Conclusión. Se reafirma la importancia del virus del dengue, Rickettsia spp. y Leptospira spp., como agentes causantes del síndrome febril en la región del Urabá. doi: http://dx.doi.org/10.7705/biomedica.v33i0.734

Mamíferos silvestres de la Reserva Natural Hacienda San Pedro, municipio de Maceo, Antioquia, Colombia

The Andean region in Colombia is home to at least 192 species of wild mammals. However, it is a highly transformed region, so the establishment and monitoring of reserves is essential for the maintenance of biodiversity. We made the inventory of the wild mammals of the Hacienda San Pedro Natural Reserve, Maceo, Antioquia. 40 species belonging to eight orders and 17 families are registered. Endangered and endemic species such as Saguinus leucopus, Aotus griseimembra, Notosciurus pucheranii and Proechimys crysaeolus were found. The site assembly presented frequent species from the Magdalena Medio region, as well as from the Central Andes. We hope that this work is a contribution to the academic practices carried out in the reserve and that it highlights its contribution to the conservation of wild mammals at the regional level.La región Andina en Colombia alberga al menos 192 especies de mamíferos silvestres. No obstante, es una región altamente transformada, así que el establecimiento y monitoreo de reservas es fundamental para el mantenimiento de la biodiversidad. Realizamos el inventario de los mamíferos silvestres de la Reserva Natural Hacienda San Pedro, Maceo, Antioquia. Se registran 40 especies pertenecientes a ocho órdenes y 17 familias. Se encontraron especies amenazadas y endémicas como Saguinus leucopus, Aotus griseimembra, Notosciurus pucheranii y Proechimys crysaeolus. El ensamblaje del sitio presentó especies frecuentes de la región del Magdalena Medio, así como de los Andes Centrales. Esperamos que este trabajo sea un aporte a las prácticas académicas que se llevan a cabo en la reserva y que resalte su aporte a la conservación de los mamíferos silvestres a nivel regional