Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the cou...Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the country, in this work, it is carried out the development of a system of wind resource assessment to determine the volume of water that a windmill pumping system can provide in a specific area. To this end, it has developed a computer program for wind resource assessment by measurements of wind speed, direction, temperature, barometric pressure and relative humidity. Measuring equipments were mounted in a wind measurement tower of 10 m high, within the premises of the University of Quintana Roo which is located along the coast. Until this day, there are records over a period of five months of the variables of wind speed, wind direction, temperature, relative humidity and atmospheric pressure. These variables were used for statistical calculations using the Weibull distributions. To give a better use of the calculated data, they were applied to the evaluation of a Pumping System.展开更多
Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help...Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help prevent biofouling, reduce the cost of using RO-fouling membranes and guarantee safe water. Culture-dependent and independent techniques were then performed in order to identify bacteria associated with RO membranes. Bacteria cultures described the presence of six pure colonies, four of which were identified through API testing. Based on 16s rRNA gene analysis, a predominant bacterium was identified and annotated as Sphingomonas sp. The 16s rRNA gene clone library, on the other hand, showed that the bacterium, Pseudomonas marincola, accounted for nearly 30% of the clone library, while the rest of bacteria were chimeras (62%) and non-representative species (3%). In conclusion, culture-dependent and independent approaches showed that two dominant bacteria were commonly observed in RO desalination membranes.展开更多
The knowledge of the chemical composition of invertebrates as sea cucumber contributes to improving our understanding of these living organisms. This study compared the chemical composition of wild sea cucumber Isosti...The knowledge of the chemical composition of invertebrates as sea cucumber contributes to improving our understanding of these living organisms. This study compared the chemical composition of wild sea cucumber Isostichopus sp., between February 2013 and January 2014. Sea cucumbers were captured by hand by artisanal fishermen and transported alive to the laboratory of Aquaculture of the Universidad del Magdalena (Colombia), where they were subsequently killed and taken to freeze until analysis. For proximate analysis 20 g of muscle were used for each sample. The analysis (in triplicate) was performed according to [1]. Significant differences (p Isostichopus sp. was similar to that reported for fresh sea cucumbers internationally traded, which indicates that it is a species with a competitive commercial value for use in food.展开更多
This paper introduces a methodology of characterization of nanostructured systems in which trans- mission electron microscopy is used as a central element of the study. Experimental studies of HREM are performed in pa...This paper introduces a methodology of characterization of nanostructured systems in which trans- mission electron microscopy is used as a central element of the study. Experimental studies of HREM are performed in parallel with studies in the Simula TEM program to stimulate high-resolution images and diffraction patterns. To confirm the accuracy of the results, studies of X-ray diffraction (XRD) were performed. In order to illustrate the methodology, bismuth oxide Bi2O3 nanoparticles are synthesized by a method of biosynthesis because this sample is rich in structural information.展开更多
Solar radiation is one of the most important parameters for applications, development and research related to renewable energy. However, solar radiation measurements are not a simple task for several reasons. In the c...Solar radiation is one of the most important parameters for applications, development and research related to renewable energy. However, solar radiation measurements are not a simple task for several reasons. In the cases where data are not available, it is very common the use of computational models to estimate the missing data, which are based mainly on the search for relationships between weather variables, such as temperature, humidity, precipitation, cloudiness, sunshine hours, etc. But, many of these are subjective and difficult to measure, and thus they are not always available. In this paper, we propose a method for estimating daily global solar radiation, combining empirical models and artificial neural networks. The model uses temperature, relative humidity and atmospheric pressure as the only climatic input variables. Also, this method is compared with linear regression to verify that the data have nonlinear components. The models are adjusted and validated using data from five meteorological stations in the province of Tucumán, Argentina. Results show that neural networks have better accuracy than empirical models and linear regression, obtaining on average, an error of 2.83 [MJ/m<sup>2</sup>] in the validation dataset.展开更多
文摘Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the country, in this work, it is carried out the development of a system of wind resource assessment to determine the volume of water that a windmill pumping system can provide in a specific area. To this end, it has developed a computer program for wind resource assessment by measurements of wind speed, direction, temperature, barometric pressure and relative humidity. Measuring equipments were mounted in a wind measurement tower of 10 m high, within the premises of the University of Quintana Roo which is located along the coast. Until this day, there are records over a period of five months of the variables of wind speed, wind direction, temperature, relative humidity and atmospheric pressure. These variables were used for statistical calculations using the Weibull distributions. To give a better use of the calculated data, they were applied to the evaluation of a Pumping System.
文摘Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help prevent biofouling, reduce the cost of using RO-fouling membranes and guarantee safe water. Culture-dependent and independent techniques were then performed in order to identify bacteria associated with RO membranes. Bacteria cultures described the presence of six pure colonies, four of which were identified through API testing. Based on 16s rRNA gene analysis, a predominant bacterium was identified and annotated as Sphingomonas sp. The 16s rRNA gene clone library, on the other hand, showed that the bacterium, Pseudomonas marincola, accounted for nearly 30% of the clone library, while the rest of bacteria were chimeras (62%) and non-representative species (3%). In conclusion, culture-dependent and independent approaches showed that two dominant bacteria were commonly observed in RO desalination membranes.
文摘The knowledge of the chemical composition of invertebrates as sea cucumber contributes to improving our understanding of these living organisms. This study compared the chemical composition of wild sea cucumber Isostichopus sp., between February 2013 and January 2014. Sea cucumbers were captured by hand by artisanal fishermen and transported alive to the laboratory of Aquaculture of the Universidad del Magdalena (Colombia), where they were subsequently killed and taken to freeze until analysis. For proximate analysis 20 g of muscle were used for each sample. The analysis (in triplicate) was performed according to [1]. Significant differences (p Isostichopus sp. was similar to that reported for fresh sea cucumbers internationally traded, which indicates that it is a species with a competitive commercial value for use in food.
文摘This paper introduces a methodology of characterization of nanostructured systems in which trans- mission electron microscopy is used as a central element of the study. Experimental studies of HREM are performed in parallel with studies in the Simula TEM program to stimulate high-resolution images and diffraction patterns. To confirm the accuracy of the results, studies of X-ray diffraction (XRD) were performed. In order to illustrate the methodology, bismuth oxide Bi2O3 nanoparticles are synthesized by a method of biosynthesis because this sample is rich in structural information.
文摘Solar radiation is one of the most important parameters for applications, development and research related to renewable energy. However, solar radiation measurements are not a simple task for several reasons. In the cases where data are not available, it is very common the use of computational models to estimate the missing data, which are based mainly on the search for relationships between weather variables, such as temperature, humidity, precipitation, cloudiness, sunshine hours, etc. But, many of these are subjective and difficult to measure, and thus they are not always available. In this paper, we propose a method for estimating daily global solar radiation, combining empirical models and artificial neural networks. The model uses temperature, relative humidity and atmospheric pressure as the only climatic input variables. Also, this method is compared with linear regression to verify that the data have nonlinear components. The models are adjusted and validated using data from five meteorological stations in the province of Tucumán, Argentina. Results show that neural networks have better accuracy than empirical models and linear regression, obtaining on average, an error of 2.83 [MJ/m<sup>2</sup>] in the validation dataset.
