Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Hydrological models are a fast and low-cost option to estimate surface runoff in a rainfall event in ungauged basins. Prior to their use, the models must be evaluated; their results, if reliable, are useful in def ining sound policies for rational management of the water resource. The purpose of this research was to evaluate the degree of f it of the numerical curve runoff Model of the extinct U.S. Soil Conservation Service (SCS-CN) and the Green-Ampt (GA) inf iltration model to reproduce direct runoff hydrograms in ungauged basins. These models were integrated into a hydrological model structured in HEC-HMS software. Seven well-def ined rainfall events and one prolonged event with intermittent precipitation occurring in the Chapingo River Basin, Mexico, were chosen. In the analysis of the set of eight events, the SCS-CN model estimated the total runoff volume better (RMSE of 5430 m3), while the GA model estimated the peak flow better (RMSE of 0.72 m3 s-1). The GA model best estimated the hydrograms of three well-def ined rainfall events whose runoff volumes were greater than 8.31 × 103 m3 and Qp ≥ 1.93 m3 s-1 with RMSE of 0.14 to 0.43 m3 s‑1, MRE of 0.20 to 0.28 and Nash-Sutcliffe eff iciency of 0.92 to 0.95. For the other four well-def ined events with runoff volumes lower than 6.35 × 103 m3 and Qp ≤ 1.44 m3 s-1, both models estimated the hydrograms identically and without effectiveness with a Nash-Sutcliffe index of -1.38 to -7.34. Estimation of the hydrogram of the prolonged event was identical in both models with an RMSE of 0.07 m3 s-1, an MRE of 0.35 and a Nash-Sutcliffe eff iciency of 0.71. The hydrogram of the prolonged event was identical in both models, with an RMSE of 0.07 m3 s-1, an MRE of 0.35 and a Nash-Sutcliffe eff iciency of 0.71.

Irrigated agriculture requires better estimates of crop water demand. The aim of this study was to estimate the evapotranspiration (ETc) in forage corn through vegetation indices obtained in situ and estimated with remote sensing in the Comarca Lagunera, Mexico. The research was carried out in 2011 and 2012 in four 900 m2 plots irrigated with a subsurface drip irrigation system. Normalized Difference Vegetation Index (NDVI) and crop coeff icient (Kc) during crop development were determined. The initial, maximum and f inal NDVI values were 0.13, 0.79 and 0.63 for both methods and in both cycles. The maximum Kc values were obtained 54 and 48 days after sowing (DDS) with GreenSeeker, and at 61 and 59 DDS with satellite images in 2011 and 2012, respectively. The results showed a good relationship between ETc estimated in situ and ETc estimated with remote sensing (r = 0.98) for both years. Although the variation of ETc using both methods was 1.2 mm day‑1, early in the cycle and 7.4 mm day-1 to flowering start-milky grains. Water needs of forage corn were estimated with similar precision using remote sensing and in situ measurements. Therefore, both methods can be used to improve irrigation scheduling and preserve water resources in agriculture.

The cocoa provides signif icant levels of carbon (C) and nitrogen (N) by the leaf litter; the change of agronomic management causes variation in the contents of these elements in the soil. The objective was to evaluate the variations of the isotopes of δ13C and δ15N between two types of cocoa (CCN51 and Nacional), located in three soil orders in the province of El Oro, Ecuador. Thirty soil samples of 0.30 m deep and 25 samples of leaf litter were taken and the abundance of the isotopes of δ13C and δ15N were analyzed. The data were analyzed including two factors, cocoa types (CCN51 and National) and order of soils (Alf isol, Entisol and Inceptisol). The results showed that the ranges of the isotope of δ13C in soil were -23.81% (CCN51, Entisol) to -26.46% (National, Entisol) and in leaf litter -27.21% (CCN51, Alf isol) to -29.86% (National, Inceptisol). The ranges of the isotope of δ15N in soil were of 7.96% (National, Entisol) and 10.48% (National, Alf isol) and in leaf litter of 4.85% (National, Entisol) to 8.38% (CCN51, Alf isol). The averages of the δ13C in the soil were plants type C3. The values of δ15N in litter and soil was an indicator of low incidence of fertilizers nitrogenous origin inorganic in National and high mineralization of N in CCN51.

La fertilidad intrínseca del suelo y la forma de riego podrían afectar la ef iciencia de la fertilización con nitrógeno (N), modif icar la meta de rendimiento, el crecimiento y el estado nutrimental de los cultivos. Se realizó un estudio con el objetivo de conocer el rendimiento, crecimiento, ef iciencia en el uso del agua (EUA), ef iciencia agronómica del N (EAN), además de medir la concentración de NO3- en el extracto celular de peciolo (ECP) y el índice de clorof ila (SPAD) en el cultivo de algodón por efecto de diferentes dosis de N y dos formas de aplicar el riego. El estudio consistió en dos experimentos establecidos en suelos considerados de alta fertilidad [˃13.0 g kg-1 materia orgánica (MO) y N-NO3- ˃ 30 mg kg], variando la dosis de fertilización nitrogenada en cada uno de ellos: a) riego rodado (FRR; 11 y 220 kg N ha-1) y b) riego por goteo (FRG; 11 a 440 kg N ha-1). La altura y número de nudos en las plantas no se afectaron por los tratamientos aplicados. Los valores encontrados en el SPAD y la concentración de NO3- en ECP se relacionaron en forma cúbica con el rendimiento del cultivo. El mayor rendimiento y la EUA se obtuvo en el experimento manejado con riego goteo. En el experimento FRR no se encontró respuesta a los tratamientos de fertilización nitrogenada. En el experimento FRG la aplicación de 440 kg N ha-1, redujo en un 43% el rendimiento en comparación con el resto de las dosis evaluadas. La EAN fue estadísticamente mayor (P < 0.001) en los tratamientos fertilizados con 11 kg N ha-1. La disminuida respuesta en rendimiento en el cultivo de algodón debido a la aplicación de N fue atribuida a las altas concentraciones de N-NO3- y MO que estuvo presente en los suelos en donde se realizaron los experimentos.

Context: Cities around the world share similar experiences of urban transformation, due to the urbanization development model that is responsible for around 70% of the global CO2 emissions. The challenge in urban matters is to work more at a city level, in order to mitigate the GCC and the effects that this produces. Method: This study case, of a very small city in Mexico, represents the perspective of Low Impact Urban Design and Development (LIUDD), contextualizing the French urban planning framework, where the water resources management is a priority as an adaptation strategy. Colima city presents a disorderly horizontal growth; therefore, the extension of impervious areas has caused run-off and road congestion, affecting the population and urban infrastructure. Results: The North-West zone represents an area of opportunity to deal with these problems. Our results show that the study area presents an important level of soil occupancy (COS = 0.76-1.00) obtaining a runoff coefficient, CE = 0.96. In addition, it has a low population density (51-100 inhabitants / ha), with 92% of motorization. In this way, the road infrastructure occupies 91% of the surface of public space, so it presents an area of opportunity for multifunctional infrastructure. The proposal, through Sustainable Urban Drainage Techniques implemented in main roads, reduces the CE to 0.90, and the volume of floods by 203%, prioritizing the active modes of transport. It is recommended a comprehensive management of water supported by a regulatory framework, which prioritizes the LIUDD. Conclusions: It is also recommended to create a coordinated agency composed by different representatives of the sectors involved, with the aim of generating multifunctional projects for the management of stormwater and mobility in public space. Also, this independent agency can be useful in managing new ways of planning the urban development, in order to mitigate and adapt the city to the climate risks that are happening.

Context: in Mexico, international trade is experiencing an increase joined by international companies in the manufacturing area, in the state of Jalisco. The research reviews the homeostasis of the assembly and exportation companies, with the idea of improving shipping logistics to automate and increase productivity, through the development and application of the continuous improvement tool called kaizen. Method: this research is based on a systemic approach. In this sense, to identify the company's homeostasis, data and information were obtained on the activities carried out by the logistics area, as well as on policies and strategies. Subsequently, through the Ishikawa diagram, the cause-effect relationship was analyzed and through a process mapping the problem of the areas of purchase, production and deposit was determined. Finally, several alternative solutions were proposed to improve management. In addition, for the development of the solutions, the problems and solutions were faced by relating them to the impact on the level of service and making a comparison between before and after implementing the kaizen. Results: The study focuses on the shipping logistics operation to automate the process and avoid bottlenecks. In this way, orders that are not sent on time become code A (urgent orders) and make the customer have a productivity rating of 60%. Therefore, when implementing Kaizen, it is possible to increase considerably up to 35% per year, with 95% satisfaction and qualification samples. It is worth mentioning that this kaizen was carried out in the Fru´s & Opt project. Conclusions: The current homeostasis of the tools mentioned in the study are basic and necessary. Also, continuous improvement tools continue to be updated and adapted; For example: Heijumka, Jidoka, Smed, Lean Manufacturing, Just in Time, Toyota Production System (TPS), 5s or Gemba, as it is a way to increase productivity, reduce costs and increase competitiveness to attract more markets International.

Context: Anthropic processes related to urban mobility have placed the issue of public transportation on the agenda of most countries in the world. In fact, compared to the private vehicle, it represents the most economical and sustainable way of exercising daily mobility. However, who use the internal combustion process, through petroleum derivatives, emit greenhouse gases and, therefore, this form of motoring mobility has become the biggest contributor to global climate change. Under this premise, the aim of this article is to analyze the externalities of greenhouse gas emissions in the public transportation of buses in the city of Tepic, Mexico. Method: The research uses data provided by the Nayarit Ministry of Environment; from which greenhouse gas emissions from public transportation were estimated using the 1996 methodology approved by the United Nations Intergovernmental Panel on Climate Change. In this sense, according to this methodology, which allows to estimate fuel consumption, the annual route was obtained by type of vehicle, as well as the vehicle's performance. Results: The greenhouse gas emissions in the city of Tepic, Mexico, approached 192 thousand tons emitted only by public transportation by bus. Although the granting of concessions has been carried out in a disorderly and arbitrary manner by the different governments, it was possible to provide an emission scenario for 2020. Conclusions: Public bus transportation in the city of Tepic faces accelerated growth, caused by the disorderly expansion of urban housing. This system has become one of the main emitters of greenhouse gases, which makes it a central issue for the implementation of public transportation policies, adopting initiatives and mechanisms to reduce emission levels, reduce externalities and contribute to the sustainability and mitigation of global climate change.

Context: At present, nanotechnology has multiple areas of action that, due to its nature, can be implemented with great versatility, given that a large number of advances in nanotechnology base their studies on how to optimize every day and industrial processes and how to favor the environment ambient. In addition to this, the manipulation of matter at this level allows creating solutions with greater projection in scientific, social and economic impact, for the purpose of this research, results will be shown at the laboratory level using cellulosic nanomaterials for the adsorption of emerging antibiotic contaminants. Method: This research was carried out at the laboratory level where it was modified by chemical cellulose methods to obtain nanocellulose by oxidation with TEMPO. A characterization of material obtained by spectroscopy techniques was performed and the adsorption of emerging antibiotic contaminants such as ciprofloxacin was evaluated. Results: Cellulosic nanomaterials have the potential to be used in tertiary water treatment in the removal of emerging contaminants such as ciprofloxacin. The results show that the cellulosic nanomaterial adsorbs ciprofloxacin by 27%. Conclusions: The nanocellulose membranes have the potential to be used in a water purification system, those membranes made only with cellulose had a lower percentage of adsorption of the contaminant than the membranes with nanocellulose.

  José Martí (1853-1895), the Apostle of Cuban independence, was an admirer the Mayan culture. This admiration was forged through knowledge of archaeological evidence, the historical and anthropological studies from his time, and by his personal contacts with Maya peoples and communities during his residence in Guatemala in1877 and 1878. That knowledge drove his of view that the culture of Nuestra América [Our America], like that of other pre-Hispanic peoples, was essential to forge nations far removed from all colonial backwardness. 

El Dorador is the title of a lost chron­icle of José Martí. The Cuban poet, before going to war, asks his secre­tary and friend Gonzalo de Quesada to rescue this text from his abundant stationery. However, neither Quesada nor the multiple editors Marti has had for more than a century have been able to fulfill this request. The present study offers some clues that bring us closer to this mysterious chronicle. Progressively, we are closer in pleasing the Martian desire before his passing in the fields of Cuba.