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

The present study analyzes the characteristics and the parameters necessary for the manufacture of a biodegradable composite material through the processes of extrusion, crushing and injection in order to optimize the mechanical properties of the composite material obtained. The thermoplastic polymers used as polymer matrix are polylactic acid (PLA), Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and a thermoplastic with starch base. Also, short flax fiber was used as reinforcement, with a length less than 3mm in length. The process of obtaining the composite material begins with the transformation of the biopolymer mixture combined with flax fiber, in a twin screw extruder for thermoplastics, where a filament of bio-composite material is obtained, which is crushed to obtain granulated material or pellets; the next process has been to transform the pellets of the composite material, by injection, into rectangular sheets with dimensions of 180 x 200 mm and thickness of 2.5 mm. To process the material in the mixing screw of the extruder, the melting temperature of the material must be maintained according to the study carried out in the differential scanning calorimetry tests. The differential scanning calorimetry (DSC), shows a range of temperatures where heat flow peaks occur, this test consists in progressively raising the temperature of the material and comparing the exothermic or endothermic processes present in the material, with this test they are obtained the glass transition, melting and degradation temperatures of the thermoplastic matrix, the appropriate handling values were: PLA (167.16 ° C), PHBV (178.62 ° C) and Starch Compound (142.71 ° C) , the parameters of temperature and pressure of injection are determined, these variables are essential to guarantee the manufacture of the different samples of composite material and in later stages destructive tests are carried out to examine the result in the mechanical properties of the biodegradable composite material.

One of the first stages in the purification of surface water is the coagulation and flocculation of suspended solids. The presence of solids alters the physical-chemical properties of water, which can affect color, taste and in many cases generate microbiological contamination. The most commonly used coagulant-flocculant is aluminum sulphate, however, the presence of residual aluminum in water has been associated with health disorders in consumers, since aluminum as a soluble salt becomes bioavailable in the human metabolism. Therefore, the possibility of replacing aluminum sulphate with non-toxic biopolymers such as chitosan is considered. Thus, the water coming from different slopes to the storage tanks of Bellavista treatment plant in the north of Quito city, was analyzed by jar tests. It was found that chitosan in concentrations of 8 ppm causes a 19.7% decrease in turbidity of raw water; at this same concentration, aluminum sulphate generates the opposite effect, producing an increase in turbidity of 19.3%. Due to this behavior, chitosan can become a viable alternative to clarify water for human consumption, in addition to its quality as a natural polymer.

Zein nanoparticles were synthesized to encapsulate carotenoids and determine the efficiency of the encapsulation under controlled experimental conditions. Carotenoids were quantitatively extracted from preconditioned samples of Capsicum annuum by cold agitation with chloroform. The total carotenoids, expressed as concentration of β−carotene, were quantified by spectrophotometric measurements, which were related to ASTA units of color. The zein nanoparticles were synthesized by the coacervation method and characterized by measurements of particle size, polydispersity and Z potential. The dye was encapsulated during the synthesis process. Using a complete factorial design 23 at 95% confidence, it was determined that the conditions in which the inclusion percentage of the dye in the zein nanoparticles is maximized, up to 88.94% were: zein concentration of 2%, temperature of 20 °C and pH 8.

In the research carried out on the environmental economic valuation, biomass and carbon production of a native forest in the city of Loja, a comparison was made with forest plantations of Eucalyptus globulus and Pinus Patula; Through a study it was possible to determine that native Andean forests have an economic environmental value of 77,783.4 USD/ha, which is higher than forest plantations that have 46344.1 USD/ha and 45,471.9 USD/ha. On the other hand, it was also found that biomass production is clearly higher in forest plantations than in native forests (E. globulus 492.59 tons/ha, P. patula 333.8 tons/ha and Native forests 151, 91 t/ha), with amounts that exceed more than 50% and which is also reflected in carbon storage, since forest plantations have higher biomass production also retain more carbon (E. globulus with 246, 30 ton/ha, P. patula with 166.93 Forest and Andean 75.96 tons/ha).

This study presents the laboratory results of the solvent injection in samples obtained from reservoir M-2, the VHR oil field of the Ecuadorian Amazon region. The objective was to determine the increase of the recovery factor in cores saturated with oil of 29.2 API degree. This study consisted of three stages: in the first stage, several EOR methods that can potentially be applied to cores, which was obtained from the M-2 sandstone, that ones were analyzed. In the second stage, an oil displacement was made using formation water, this result was used as a reference point. In the third stage, the oil was displaced with solvent and compared with the result of the second stage. For the second and third stages, a simple model based on the Buckley-Leverett theory was developed. This model helped to quantify the increase in the recovery factor. The screening criteria determined that the conditions were appropriate for solvent injection. The reference point gave a recovery factor of 25.7 percent. On the other hand, the displaced oil after using solvent was 43.74 percent. This result means an increase of 18.04% in the recovery factor. The numerical method gave a recovery factor of 49.97 percent, which is 6.23 percent higher than the experimental values. The experiment allowed to conclude that the option of injecting solvent is very practical for use in a pilot project for the M-2 reservoir of the VHR field of the Ecuadorian Amazon region.

The purpose of the present study was to establish if the application of the low salinity water injection (LSW) is effective for the reservoir and fluid conditions of the lower U sandstone in the Paka Norte oilfield of B15. In addition, it was looked for evaluating the profitability that oilfield could generate with this EOR technique. For the development of this project a workflow was considered with the objective of processing and validating the information, building the dynamic model, making the historical adjustment of pressure and production data, generating several forecast cases and their respective economic study. Reservoir model shows that Original Oil in Place was 79 million barrels. The base case pointed out that the oilfield would produce 7.49 million stock tank barrels of oil until 2028 with a recovery factor of 10.56%. Production scenarios indicated that accumulated production could be doubled and a recovery factor of around 20% could be reached. Low salinity cases showed additional recovery factors of 0.5 to 0.6% contrasted with high salinity cases. The economic analysis determined that low salinity water injection had higher NPV and IRR than high salinity water injection.

The goal of this article is to determine the loss of income through the estimate of the expenses of the tax expediture corresponding the Environmental Tax for the Vehicular Pollution and its impact in the GDP of Ecuador during the period 2015-2017. The method used is a descriptive investigation based on numbers for the period afore mentioned, like this, taking into account the fact that this is an exploratory research, it is going to be based on the participation of this sector in the GDP, using the micro data available in many Statistic Databases of the Ministry of Economy and Finance (MEF) as well as in the Internal Revenue Service (IRS). After that, we proceed to do a relational analysis of the representation of the ETVP regarding the Total Expense other Taxes, and finally it is concluded and analyzed with the quantification of this sector that in this concept it is not attributed to the GDP of Ecuador.

 Wildfires yield severe impacts in Ecuador. The Ministry of Environment of Ecuador declared that wildfires destroyed 21,570 hectares in this country in 2012. The same fire season cost to the Metropolitan District of Quito, the capital of Ecuador, approximately 50 million dollars. In spite of the losses that wildfires produce, it is still unknown how climate influences fire occurrences in Ecuador. This is the first investigation about fire weather in the tropical Andes. This research quantifies wildfire danger as a function of meteorological variables. The investigation used the McArthur’s Forest Fire Danger Index. Since there is no local fire weather index, the McArthur’s metric was considered a suitable choice because it was designed for Eucalyptus forests, which are dominant in wildfire-prone regions in Ecuador. This research concluded that the McArthur’s Forest Fire Danger Index is indeed a useful metric to evaluate wildfire risk in the Ecuadorian Andes. Using this index, the results show with a quantitative approach that the fire season in this region spans from July to November

Workover of wells is one of the most important processes in the oil industry because it recovers or increases the hydrocarbon production of an oil well that, because of mechanical conditions or the reservoir, is producing volumes less than their optimal value. The workover process of the national oil company Petroamazonas EP in an oilfield in the Ecuadorian Oriente Basin was analyzed in order to define an improvement proposal using tools commonly used in Industrial Engineering. Considering the point of view of the clients of the process, it was determined that the parameter subject to improvement is the time. In order to determine the operations to be optimized, the available information of the workovers made in the oilfield, from January 2015 to January 2017, was collected and analyzed. Using Pareto analysis, two operations to be improved were determined: Initialization and Completion. For these operations, control charts were performed in order to determine values outside the expected ranges of time. At the farthest points a cause-and-effect analysis was applied to determine the main cause of the failure. Consider i ng the results of the analysis, a proposal was developed to improve the workover process

Currently, the investigation of the difficulties that the new university faculty is going through is essential for the generation of alternatives that allow to support their professional development. The proposed objective allowed to establish the problems of the new university teaching staff in their teaching function. This study responds to a qualitative approach. The subjects investigated were 68 new teachers from the Central University of Ecuador. In the methodology, the interview was used through a structured base guide in order to understand the meaning of the narratives of the participants. The results achieved, allowed to reveal that, of the total of protagonists, it was demonstrated that a 34.10% of novice teachers, pointed out that their problems in the teaching function, respond to the lack of basic knowledge of the students regarding the subjects taught. While 56.65% of participants said that their limitations respond to institutional constraints. Finally, a 9.25% of beginners, mentioned that their drawbacks, are due to the little experience they have in new subjects, which are assigned in their academic units. It was concluded that the problems of the new university teaching staff in their teaching functions are: the lack of support from the authorities to meet their requirements at the classroom level, low levels of knowledge mastery of the students and the little professional experience of the teaching staff. new subjects that are established according to the needs of professional careers.