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ANALYSIS AND COMPARISON OF 20 EMPIRICAL EQUATIONS FOR REAERATION RATES IN URBAN RIVERS
No full textAccurate measurements of the pollution in urban basins are essential for the development of effective management strategies. One important parameter is the reaeration rate, which allows for the evaluation of the quality and self-purification rate of water bodies. The reaeration rate can be determined using a variety of methods, such as empirical and semi-empirical equations that can rapidly produce estimates based on hydraulic and hydrodynamic variables. However, depending on the variables, these equations often produce very different results and can lead to underestimated or overestimated values. In order to test these methods, we evaluated 20 empirical equations in three urban rivers in the city of Bogota and categorized them into four groups. Principal component analyses and a dendrogram analysis were performed to compare the equations, revealing two consistent groups of equations for the three rivers. The first group consisted of equations from Langbein and Durum (LD), Padden and Gloyna (PG), and Bansal (B), while the second group consisted of equations from Owens et al. (OW) and Owens and Gibbs (OG). Equations from Thyseen et al. (TH) and Negulescu and Rojanski (NR-DL) did not present reliable clusters due to the high magnitude of their results compared to the other equations. Finally, the Tsivoglou and Wallance (TW), Grant (G), and Tsivoglou and Neal (TN) equations indicated inverse relationships compared to other equations. Hydraulic variables for velocity and water depth presented the greatest sensitivity and exhibited strong relationships with the magnitudes of the reaeration rates
Colombia Life Expectancy and War 1985-2018
No full textThis text identifies the unconstitutional state of affairs in Colombia Republic since1984 to 2018about Peace, the internal armed conflict. In this sense the text search causalities between not registered victims by the justice service in the framework of this conflict and their correlation with the mortality causes and the average life time expectancy by each of these causes at the national level
Life cycle assessment including traffic noise: conventional vs. rubberized asphalt
No full textPurpose: It is estimated that in Colombia around 25 million tires are disposed of yearly. The management of discarded tires is still a major problem considering that 3 of 10 disposed tires end up on sidewalks, separators, parks, wetlands, and even in front of houses. Additionally, mainly in urban and suburban zones near the main roads, noise is one of the central factors that affect people’s quality of life. In this article, a life cycle assessment (LCA) from cradle to grave of rubberized and conventional asphalt pavements was employed to quantify the consequences associated with the implementation of the alternative technology and the present engineering practices. LCA was performed involving the local materials and available machineries in Colombia, and the inclusion of traffic noise as part of the LCA. Methods: LCA in this study involves two methods: attributional LCA (ALCA) and consequential LCA (CLCA). To include the effect of traffic noise in the LCA, a methodology developed by the Swiss author Gabor Doka (2003) was used. Estimation of material’s quantities and their characteristics, noise levels, logistics, and production were done based on a Colombian case study. Results and discussion: Damage assessment showed that conventional asphalt (CA) impacts 67% more in human life than rubberized asphalt (RA). Traffic noise assessment results presented that CA has about 38% more impact in human life compared with RA, then, considering the study period (25 years), a reduction of 2.8 dB in noise emission due to the implementation of RA represents a considerable positive impact in human life. The total effect in ecosystems showed that CA has 40% more impact in the extinction rate of species than RA. In total, CA causes 43% more impact in resources than RA. Consequential assessment showed that the implementation of the RA represents 48% less environmental damage than the conventional alternative. Conclusions: RA is a more environmentally friendly alternative compared with CA because it requires less raw material usage, and less mix production due to its better performance (less maintenance and rehabilitation interventions). RA represents a suitable alternative to divert tons of used tires from the landfills
Relevance of Hurst\u27s pattern in equity portfolio management
No full textIn this article, the behavior of the returns of some assets of MILA is analyzed, with the objective of looking for evidence of persistence and evaluating the impact of their presence in the decision making of investment portfolios. The methodology of the rescaled range is used in the estimation of the Hurst coefficient as a measure of persistence and the results are verified with the adjustment of Anis and Lloyd and the estimation of Higuchi. An inferential process is added to the Hurst coefficient for each of the assets analyzed. The performance of portfolio optimization including estimates of persistence and the results of its inference were compared with independently optimized portfolios. A better risk-return relationship is observed by including the pattern of persistence, only when the inference is supported by evidenc
The authoritarian mind: From political metaphors to the constitution of a social identity
No full textThis paper deals with the mental processes of authoritarians. Firstly, we explore these processes from the perspective of the type of metaphors authoritarians embody; we understand those metaphors as a conceptual framework that configurates human thought. This framework is understood as social constructs which are incorporated in the individual as a social being. We inquire about some frameworks to which the authoritarian thought appeals. One of them is the framework of the family, and the father as the main figure, which explains hierarchical relations. Another one is the friend-enemy dualism: through this, authoritarian identity establishes intersubjective relations that correspond to a Manichean vision of the world: friends are those who agree with the metaphors that the authoritarian embodies, enemies are the others. Thus, the authoritarian conceives him or herself as a hero, and so this figure (as a conceptual framework in and of itself) allows us to understand certain imaginaries and their relationship with a personal objective: such an objective ceases to be individual to be the goal of the collective, and the authoritarian person proclaims him or herself as the guarantor of its achievement. Finally, after studying frameworks as social constructs we proceed to inquire about the character of the authoritarian person as a symptom of a particular constitution of identity. Such a constitution reminds us of the figure of the suc-cessful psychopath, whose identity is shaped by inflexible agendas and an outlook on the world that even put his or her own integrity at risk
Handbook of Research on Management Techniques and Sustainability Strategies for Handling Disruptive Situations in Corporate Settings
No full textFaced with chaotic environments, it is not possible to make totally efficient forecasts, especially when it is necessary to analyze events with multiple variables and micro, small, and medium enterprises (MSMEs) constantly face events that escape the laws of the market. The handling that has been given to the crisis caused by the coronavirus has been trial and error, and the economic, social, and environmental results remain to be seen. The markets and the world are chaotic. With the markets in chaos due to the COVID-19 pandemic, it is important to look at the methods used in these environments to promote business success. The Handbook of Research on Management Techniques and Sustainability Strategies for Handling Disruptive Situations in Corporate Settings elaborates on the skills, techniques, and tools that are more useful for these environments and identifies what makes companies that work well in organizational chaos and in chaotic economic environments perform better than companies that are well organized. Covering topics such as strategic management, multidimensional chaos approach, and the global unstable market, this book is essential for managers, executives, academicians, policymakers, entrepreneurs, researchers, undergraduate and graduate business students, and any person interested in state-of-the-art business issues
Cálculo Diferencial
No full textEl Cálculo Diferencial, abordará en su primera unidad los fundamentos de las matemáticas básicas necesarios para que el estudiante empalme el bachillerato con la universidad de manera gradual, sin mayores dificultades; en la segunda unidad, se conceptualiza sobre las funciones, los límites y la continuidad fundamentos del Cálculo Diferencial; en la tercera unidad se obtienen las derivadas de las familias de funciones algebraicas y trascendentes; y en la unidad cuatro se aplican las derivadas a situaciones problémicas en geometría, optimización, razones de cambio relacionadas, construcción de gráficas y solución de límites. La ruta de aprendizaje es piramidal, es decir, se parte de las unidades de aprendizaje de menor complejidad hasta llegar a las de mayor como se ilustra la figura 2.https://ciencia.lasalle.edu.co/blearning_agropecuarias/1000/thumbnail.jp
Tópicos de Datos y Textos
No full textEl exceso de información que vivimos actualmente nos reta a buscar y establecer nuevas metodologías para extraer información relevante a partir de datos en forma de textos escritos; en este sentido, el uso de distintas tecnologías representa un apoyo fundamental en la transformación de los datos en información, siendo el Machine Learning (ML) un conjunto de técnicas con potencial para lograr dicha transformación. En términos generales, el ML puede clasificarse en varios tipos, el aprendizaje por refuerzo, el supervisado, el no supervisado y recientemente se habla de aprendizaje semisupervisado; en todo este grupo de clasificaciones es posible realizar regresiones, agrupaciones, asociaciones, o clasificaciones, valga la redundancia, entre muchas otras técnicas y usos.https://ciencia.lasalle.edu.co/blearning_esc_negocios/1000/thumbnail.jp
Biological and photocatalytic treatment at pilot plant scale of synthetic coloured wastewater produced in university teaching laboratories
No full textDyes and chemical additives, present in wastewater produced in Microbiology teaching laboratories generate high contamination. They are difficult to degrade and according to the Colombian regulation should be treated before final disposal. In this work, a pilot plant was used to treat synthetic wastewater (SWW) containing a mix of dyes (10 mg/L Crystal Violet, 10 mg/L Congo Red, 10 mg/L Malachite Green and 10 mg/L Fuchsin Gram). To remove this type of contaminants initially, the capacity of a fungal/bacterial sludge (FBS) on a 1 L scale was determined. Subsequently, the operating conditions that favor tertiary treatment were selected by using TiO2/UV photocatalysis at 0.25 L scale and finally the complete treatment plant was integrated and evaluated (Pre-treatment, secondary treatment and tertiary treatment). The SWW that entered the plant had the following characteristics: Chemical Oxygen Demand (COD): 4033 mg/L, Biochemical Oxygen Demand (BOD5): 2750 mg/L, Color Units (CU): 2010, BOD5/COD ratio: 0.68, 19_3 ºC and a pH of 7.0. After 37 hours of plant operation, overall removal was 98 _ 3%, 99 _ 6% and 99 _ 8%, for COD, BOD5 and CU. Demonstrating that integration of unitary operations in a sequential and orderly manner, are a novel alternative for treatment of this type of wastewater
Model management plus for the creation of technology-based spin-offs
No full textDuring the last years, universities have been developing the concept of creation of technology-based enterprises (TBE - spin off) as an answer to a global culture of development of science, technology, and innovation as mechanisms to structure new models of entrepreneurship in universities, being nurtured by technology and private-public alliances. With that in mind, the Plus Management Model for the Creation of Technology-Based Spin Offs Project was developed. It was aimed at developing a systemic methodology so universities, enterprises, and the government can articulate their efforts to develop spin offs of technology-based enterprises; thus, science, technology, and innovation become the core of competitiveness, the development of the society and organizations