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Innovación tecnológica: dispositivo para el rodillado, en tornos horizontales, de los muñones de ejes. 技术创新:在卧式车床上轧制主轴的装置。
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-09-03 DOI: 10.5377/NEXO.V25I1.794
Luis Orlando Martín Carvajal, A. G. Domínguez
{"title":"Innovación tecnológica: dispositivo para el rodillado, en tornos horizontales, de los muñones de ejes.","authors":"Luis Orlando Martín Carvajal, A. G. Domínguez","doi":"10.5377/NEXO.V25I1.794","DOIUrl":"https://doi.org/10.5377/NEXO.V25I1.794","url":null,"abstract":"The design consists of a device, adapted to a horizontal lathe, for the surface plastic deformation using a roller for refurbishing damaged shafts in the core of the product by friction during operation. These are shafts working under conditions of high contamination by dirt and low speeds to endure high loads, in contact with sliding bearings lubricated by splashes. After two or three years of work they have to be withdrawn from operation due to the high deterioration of the stumps, while internally they have no symptoms of fatigue. After applying the surface treatment to the shaft, the for symptoms of deterioration appear during a period of time which is twice, respect the normal one. The device was designed, manufactured and put into operation adapted to the horizontal lathe. The device was implemented in the recuperation of the axels for the cage cars in the railway transportation of sugar cane. It guarantees the quality of the surface finish and the wear resistance, without affecting railway safety requirements. Key words: rolling of cylindrical surfaces; surface plastic deformation.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Digitalización del entorno a partir de un LIDAR HDL-64E 使用HDL-64E激光雷达对环境进行数字化
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-09-03 DOI: 10.5377/NEXO.V25I1.795
Denis Eduardo Hernández García, José de Jesús López Jiménez, J. G. Barbosa, J. B. H. Ramos, F. J. O. Rodríguez, Ricardo González Barbosa
{"title":"Digitalización del entorno a partir de un LIDAR HDL-64E","authors":"Denis Eduardo Hernández García, José de Jesús López Jiménez, J. G. Barbosa, J. B. H. Ramos, F. J. O. Rodríguez, Ricardo González Barbosa","doi":"10.5377/NEXO.V25I1.795","DOIUrl":"https://doi.org/10.5377/NEXO.V25I1.795","url":null,"abstract":"This paper proposes a map building system for an autonomous vehicle equipped with LIDAR technology, capable to obtain more than one million points per second. This paper proposes a Fast Local Map building Approach (LM) that it is use for autonomous local navigation, and construction of Global Map (GM) 2D and 3D for modeling the whole environment crossed by the vehicle. During the process of the global map building, we estimate the location of the vehicle with respect to its initial position. Keywords: 2D map building, 3D map building, localization.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Diagnóstico de Procesos Previos a la Aplicación de la Manufactura Esbelta 执行前的诊断流程制造Esbelta
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-09-03 DOI: 10.5377/NEXO.V25I1.792
Yolanda Juárez López, A. Rojas, Jorge Armando Rojas Ramirez
{"title":"Diagnóstico de Procesos Previos a la Aplicación de la Manufactura Esbelta","authors":"Yolanda Juárez López, A. Rojas, Jorge Armando Rojas Ramirez","doi":"10.5377/NEXO.V25I1.792","DOIUrl":"https://doi.org/10.5377/NEXO.V25I1.792","url":null,"abstract":"In implementing a solution guide for manufacturing problems such as an unsatisfied demand, a previous diagnosis is necessary. In this paper we describe how this was developed for the case of railroad material enterprises at the Mexican State of Hidalgo. The phases considered are: the description of the system under study, the capture and assess of the system performance, the definition of the observed problems, and its association with the causes generating them. As the performance evaluating criteria the Lean Production paradigm, originated in Japan, has been selected, due to its adequacy to the case because of its focus in process waste reduction and participative problem solving. For this case, the wastes to cope with are the long set-up times, the high rate of bad products, and the lack of adequate equipment maintenance.DOI: http://dx.doi.org/10.5377/nexo.v25i1.792 Nexo Revista Cientifica,Vol. 25, No. 01, pp.09-17/Junio 2012","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
El costo de capital y su incidencia en los métodos de flujo de caja descontados 资本成本及其对折现现金流法的影响
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-09-03 DOI: 10.5377/NEXO.V25I1.793
J. Medina, G. Pérez
{"title":"El costo de capital y su incidencia en los métodos de flujo de caja descontados","authors":"J. Medina, G. Pérez","doi":"10.5377/NEXO.V25I1.793","DOIUrl":"https://doi.org/10.5377/NEXO.V25I1.793","url":null,"abstract":"A techno-economic feasibility study in any branch of engineering or any kind of business involves knowing a measure of the investment profitability. Currently, no one discuss that for a solid basis decision making it should be used discounted cash flow (DCF), despite the persistence of a widespread forms (i.e. payback period, benefit / cost). The objective of this paper is to analyze, critically, the relevance of the methods used to make comparisons between mutually exclusive projects as well as suggest alternative ways of analysis that consider the impact of different rates of capital cost and constrain the decision in an appropriate way. The proposal presented here allows exclusive alternatives ordering with an approach that include a more complete view on the problem. The most interesting result is related to the sensitivity of the methods on the inherent decision variables involved in them. Keywords: DCF; cost of capital; mutually exclusive alternatives; project profitability","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Caracterización de la vegetación arbórea y arbustiva con potencial de servicios ambientales, al este del lago de Nicaragua 林木定性为arbustiva环境服务的潜力,尼加拉瓜湖的东
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-08-23 DOI: 10.5377/NEXO.V25I1.782
S. Gámez, Estanislao Salazar Quiroz
{"title":"Caracterización de la vegetación arbórea y arbustiva con potencial de servicios ambientales, al este del lago de Nicaragua","authors":"S. Gámez, Estanislao Salazar Quiroz","doi":"10.5377/NEXO.V25I1.782","DOIUrl":"https://doi.org/10.5377/NEXO.V25I1.782","url":null,"abstract":"This study was carried out east of Lake Nicaragua. To identify remaining areas of forest with high potential for environmental service. Six fragments of vegetation were selected. Within each fragment was identified representative vegetation, and here was established a temporal measurement plot (10,000 m 2 ). Was taken information from species and diameter measured at breast height (DBH) for all individuals with a diameter greater than 2.5 cm. The variables studied were: Diversity, use and management of forest, carbon stocks. Simpson and Shannon-Wiener indices agree that fragment 3 is the most diverse presenting 21 families, 25 genera and 30 species. Forest areas provide various environmental services. Biodiversity indices suggest that most of these fragments harbor an important diversity of species of trees and shrubs. Keywods: diversity, environmental, forest, Lake, Nicaragua","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70884999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Asentamientos poblacionales periféricos más seguros. Instrumental para el diseño y evaluación de la calidad ambiental 周边人口定居点更安全。环境质量设计与评价工具
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-06-28 DOI: 10.5377/NEXO.V24I2.659
Fredy del Pozo Gómez, Graciela Gómez Ortega
{"title":"Asentamientos poblacionales periféricos más seguros. Instrumental para el diseño y evaluación de la calidad ambiental","authors":"Fredy del Pozo Gómez, Graciela Gómez Ortega","doi":"10.5377/NEXO.V24I2.659","DOIUrl":"https://doi.org/10.5377/NEXO.V24I2.659","url":null,"abstract":"The vulnerability of settlement before any situation and territorial scope, is a concern, due inter alia to their strong influence on the development policies of management to disaster or adverse external events affecting the normal development of the people; Summary to diagnose the environmental quality of urbanization in a discrete space, as it is the case of the peripheral housing estates, allows analyze those factors that influence the vulnerability of these and make recommendations for implementing environmental policies that mitigate the risks. On the basis of that vulnerability is a dynamic concept that examines the risk factors, continues an instrumental for environmental assessment of settlements population peripherals (APP), in particular the conditions of the city Santiago de Cuba, where it has considered this component in its evaluative indicators. You expose instrumentation reference and his categorical system: variable, subvariables, evaluative parameters and scale of values, which is the essence of the instrumental designed theorist; likewise are histograms and arrays that comprise the instrumental assessment workshop. It will serve to assess settlements in operation and for the design of new ones, and can be generalized to other territories. Key words: Peripheral population settlements; environmental quality; vulnerability","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70884671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
El producto distribucional de (fórmula) （公式）的分配乘积
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-06-28 DOI: 10.5377/NEXO.V24I2.661
M. A. Aguirre, Marta García
{"title":"El producto distribucional de (fórmula)","authors":"M. A. Aguirre, Marta García","doi":"10.5377/NEXO.V24I2.661","DOIUrl":"https://doi.org/10.5377/NEXO.V24I2.661","url":null,"abstract":"En este articulo se le da un sentido al producto distribucional entre (formula) y (formula) usando la transformada de Fouriere de  Como consecuencia se obtienen este producto multiplicativo por medio de una serie de derivadas de la delta de Dirac en  En particular se obtiene el producto multiplicativo (formula)  (ver formula (21)) Palabras claves: Distribuciones; producto de distribuciones; delta de Dirac.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Aislamiento e identificación de microorganismos en biopelículas provenientes del Castillo de Chapultepec, Ciudad de México. 墨西哥城查普尔特佩克城堡生物膜中微生物的分离与鉴定。
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-06-28 DOI: 10.5377/NEXO.V24I2.656
L. Aguilera, J. A. N. Zapata, E. D. L. Cruz
{"title":"Aislamiento e identificación de microorganismos en biopelículas provenientes del Castillo de Chapultepec, Ciudad de México.","authors":"L. Aguilera, J. A. N. Zapata, E. D. L. Cruz","doi":"10.5377/NEXO.V24I2.656","DOIUrl":"https://doi.org/10.5377/NEXO.V24I2.656","url":null,"abstract":"Today microbiology is based on pure cultures and separate microorganisms, pure cultures really do not exist in nature, because that microorganism are combined into large colonies slimy (biofilms) in which the various individuals establish relationships and dependencies. Only in the United State of America is estimated that biofilms cause billions of dollars in energy losses, equipment damage, product contamination and medical infections. This paper presents the results of the isolation of microorganisms by microbiological and molecular methods, from biofilms located in the Castle of Chapultepec in Mexico City. In the biofilm coexist different genres of filamentous fungi such as Cladosporium, Mucor, Alternaria, Aspergillus, Aureobasidium, Rhodotorula and others in those biofilms; besides bacterial genera as Bacillus, Pantoea, Kokuria, etc. Many of these microbial genera have been widely reported as a participating in biodeterioration processes to monuments and others are reported as contributing to its restoration, so this work opens the door to future researches that allow biological restoration of monuments, conservation and development of new biotechnological processes. Keywords: Microbiology; pure cultures; biofilms; isolation of microorganism; microbiological methods; biodeterioration processes.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70884485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Interfaz Gráfica Computacional para Destilación Multicomponente utilizando Métodos Cortos 使用短方法的多组分蒸馏计算图形界面
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-06-28 DOI: 10.5377/NEXO.V24I2.660
A. O. Mirón, G. D. Hernández, I. Bazan, G. E. G. Landero, L. Bazán, E. H. Aguilar
{"title":"Interfaz Gráfica Computacional para Destilación Multicomponente utilizando Métodos Cortos","authors":"A. O. Mirón, G. D. Hernández, I. Bazan, G. E. G. Landero, L. Bazán, E. H. Aguilar","doi":"10.5377/NEXO.V24I2.660","DOIUrl":"https://doi.org/10.5377/NEXO.V24I2.660","url":null,"abstract":"In this work, we developed a graphical interface that determines by steady-state simulation the number of plates required for multicomponent distillation process and the composition of distillate and bottoms flow of a distillation tower using short-cut methods. The graphical user interface was built in the programming language Python 2.5, allows to present the input and output data for the case of distillation columns operating in steady state. The results of using the graphical interface shows a simple way to make preliminary designs of distillation towers and its potential as support material for the study and understanding of basic concepts in multicomponent distillation. In a later work it will can display the dynamic model performance through scheduled disturbances in operating conditions.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70884812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Morteros a base de vidrio de desecho/escoria de alto horno; activación mecanoquímica del vidrio en soluciones alcalinas. 以废玻璃/高炉渣为基础的砂浆;玻璃在碱性溶液中的机械化学活化。
IF 0.3
Nexo Revista Cientifica Pub Date : 2012-06-28 DOI: 10.5377/NEXO.V24I2.657
L. Espinoza, I. García
{"title":"Morteros a base de vidrio de desecho/escoria de alto horno; activación mecanoquímica del vidrio en soluciones alcalinas.","authors":"L. Espinoza, I. García","doi":"10.5377/NEXO.V24I2.657","DOIUrl":"https://doi.org/10.5377/NEXO.V24I2.657","url":null,"abstract":"Composite cements of Blast Furnace Slag (EAH) and Waste Glass (WG) were investigated. A fraction WG was subjected to mechanochemical activation aiming to solubilize its SiO4 to obtain solutions of sodium silicate (SS) with silica modulus greater than zero to improve the compressive strength of the cements. With the solutions obtained by AMQ, composites of 0 to 100% WG were prepared, and as referred to cements 100% BFS with standard alkaline activation. The strength of the latter decreased after increasing the Na2O content and decreased when the curing temperature was increased to 60oC. In contrast, 100% WG cements required very aggressive chemical activation conditions (12% Na2O at 60°C) to obtain good mechanical properties. The composites with 25 and 50% WG required activation conditions similar to those 100% EAH cements, while those cements with 75% WG required activation conditions similar to those of 100% WG.Keywords: waste glass, blast furnace slag, mechanochemical activation.DOI: http://dx.doi.org/10.5377/nexo.v24i2.657","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2012-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70884863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
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