Introduction. The delay in construction works is one of the biggest problems that affect this industry, giving rise to cost overruns and exceeding initial estimates of time with direct repercussions on the schedules, which can lead to more serious problems such as disputes, legal actions and abandonment of the draft. Objective. Determine the potential factors that cause construction delays during the project execution stages and provide actionable recommendations as a tool to minimize repercussions and optimize time and resources. Methodology. The technique used in this study was convenience or snowball sampling, which belongs to the class of non-probabilistic sampling techniques, the sample elements are identified for convenience and through reference networks. A questionnaire was developed to assess contractors' perceptions of the relative importance of causes of delay in the construction industry and the most important delay factors were determined using the Relative Importance Index (RII) method. Results. The result determines that incorrect planning, financing and payments for finished work by the client, lack of communication between the parties, inadequate experience of the contractor and slow decision-making on the part of the owners, are among the first important causes of delays. Conclution. By clearly identifying the factors that cause delays in projects, the corresponding recommendations are obtained to reduce the impacts that these generate and so that professionals in the branch can better understand the dynamics of project management in construction.

Introduction. Preventing injuries in athletes and lowering the costs produced by them, continues to be a great concern for all participants in the field of sports training. The aforementioned is also a priority within futsal; The very characteristics of this sport make its players prone to frequent injuries. In this sense, the theoretical-practical experiences have revealed the importance of plyometric exercises not only to improve the physical performance of athletes, but also to prevent injuries. Objective. Systematize the theoretical - methodological elements on the importance of plyometric work for the prevention of injuries in futsal players. Methodology. The research followed a descriptive, non-experimental methodology, with the use of theoretical methods and the RSL (Systematic Literature Review); All of this allowed us to carry out a bibliographic search in notable databases. Results. A total of 42 sources were consulted, in a range between 2010 and 2020, of which, according to inclusion criteria, 15 were considered potentially relevant. Derived from the above, 3 fundamental criteria are established: the importance of plyometric work in the prevention of injuries in futsal; the existing limitations in the Ecuadorian context on research related to this topic; the need to develop training processes to favor the introduction of this effective alternative within futsal training. Conclusions. It is concluded that indeed, the literature consulted confirms the importance of plyometric work for the prevention of injuries, its use being very beneficial in the case of futsal, if it must be meant that to optimize its use it is necessary to have a coaching staff and players preparations that can introduce plyometric work to prevent injuries that may arise as part of training or competition.

Introduction: In the city of Cuenca-Ecuador there are several drinking water supply systems, some of which are located in urban expansion areas and exposed to threats. Object: To analyze the physical vulnerability and exposure to the threat of mass movements of the Culebrillas drinking water system, which is located in the urban expansion zone and covers a part of the city. Methodology: A qualitative methodology was applied and an interview form was used with technicians from the Public Telecommunications Company, Drinking Water and Sewerage Company to collect information on each of the vulnerability indicators of the components of the system, which were weighted to obtain a physical vulnerability index, which allowed determining the level of vulnerability, the criteria for weighting the Delphi method was applied Aquaculture and Fisheries and Technical Secretariat for Risk Management. Results: The results indicate that the Culebrillas drinking water system in its components: catchment, has an index of 20 points representing the level of low vulnerability; driving, with 25 points equals low; treatment plant with 19,3 points represent low; distribution, which in turn is composed of the distribution reserve tanks with 25,2 points corresponding to low, and the distribution network with 48,8 points Driving, with fewer tanks and distribution network are in high level areas. Conclusion: This study constitutes a pilot model to evaluate the other systems that supplies the city of Cuenca, as well as, it could be replicated in other populated centers of the country.

In the present research, a 50-year projection was proposed for a social single-family housing bioclimatic evaluation located in Macas parish, belonging to Morona Santiago province, and characterized with a mega-thermal rainy climate. The research focuses the analysis and evaluation of the most important architectural elements and climatic factors of the sector. Bioclimatic strategies proposed by Piña (2019) were applied. Climatic conditions and thermal behaviors predictions were calculated with Meteonorm software hence obtaining Energy Plus Weather format and allowed to carry out BIM Energy Simulations by using Design Builder software. The results corroborated the insertion of passive bioclimatic strategies to the BIM to improve the internal thermal comfort behavior. Within the aim of evaluating climatic behavior over the time, the research methodology was stablished as experimental according to its nature, since variables such as: climate, comfort and construction systems were manipulated. The temporal scope has a retrospective and prospective longitudinal approach since it considered 10 years historical data from INAHMI and a projection of 50 years. A probabilistic sampling technique was used, to carry out a multistage sampling where the existing climates in Ecuador was the universe while the population concentrated the cantons with tropical rainy equatorial climate. The evaluation of low-income housing, with passive bioclimatic strategies, brings out how specific strategics can maintain the internal comfort level for social housing users over time.

The housing projects in the city of Cuenca - Ecuador, only satisfy the needs of the housing deficit in the middle and high sectors, because the cost is too high for the lower social class, due to the lack of regulations and specific studies to determine the optimal urban soils, construction systems and design strategies to promote low-cost housing. The research project, in addition to considering the social conditions of habitability of the low-income population, to establish the spatial requirements, as well as the most appropriate location for the implementation of the project, allows to establish design strategies to achieve a sustainable and affordable proposal to the social group of study, supported by quantitative and qualitative methods. At the end of the research, a set of guidelines and recommendations for architectural design and construction will be obtained for housing projects for the low-income population categorized in the social stratum C- and D in the city of Cuenca, and could be applicable in any city in Ecuador or Latin America that has similar conditions to the study universe. The impact of the research will be evidenced in the potential public policies of habitability generated through regulations or ordinances in the city of Cuenca - Ecuador, through the design and construction recommendations obtained in the research.

Problemic teaching is one of the approaches used in Cuba in order to teach Physics. Nevertheless, in the class observation of the subjects: Applied Physics and Radiation Physics for Medical Biophysics Senior Technicians in the University of Medical Sciences in Matanzas, it could be noticed that there are some limitations to find the problemic in the application of the problemic teaching by professors. The objective of this article is to show the results of specialists’ assessment on the usefulness degree of the redesigned procedure: search of problemic, for it to be applied in the lessons plan of Physics for Medical Biophysics Senior Technicians. Analysis - synthesis was the method used in the bibliography studied on didactics of Physics, problemic teaching and physics. Hypothetical - deductive method was used in the procedure redesign. A non- probabilistic sample was used, taking into account the authors’ possibilities to hand in the document with the proposal to the specialists who teach physics and then, picking up the instrument. It is necessary to widen the study concerning the sample of specialists in order to confirm the favorable usefulness criterium of the procedure designed, as well as inserting it in the teaching of physics to generalize the results through the application of scientific methods, particularly in the major in Medical Biophysics Senior Technicians.

Introduction: The consumption of diesel fuel in the country represented 36.61 [%] of the demand for petroleum derivatives in 2019, which is why it seeks to propose savings alternatives in the land freight transport sector. For this reason, the influence of an upper cabin fairing (windbreaker) on the drag force, which is generated when the truck moves forward, displacing a large amount of air that flows through the exterior and interior of the truck, was analyzed. Objective: To analyze the influence of a higher fairing on the drag force of a truck using the one-dimensional equation of the drag force and computational fluid dynamics software. Methodology: This effect was estimated using the one-dimensional drag force equation, which relates the drag coefficient, air density, frontal area, air speed and truck speed, with the help of a software of computational fluid dynamics (CFD), which requires a simplified geometry at 1: 1 scale of the truck and the upper fairing, the domain is generated and the boundary conditions governing the physical phenomenon are taken. Results: A decrease of 0.102 [kN] is obtained at a truck speed of 40 [km / h], as the speed increases to 120 [km / h], the force decreases by 0.788 [kN]. Conclusions: There is a reduction of 8.734 [%] in the drag force when using the upper cabin fairing, this is complemented by the study carried out on fuel consumption on the road where there is a saving of 4.63 [%] with the use of the upper cabin fairing.

Introduction. Soccer is a team sport, turning out to be the most practiced in the world. With the historical passing of the game systems used in this sport have varied from an ultra-offensive system to the present time that variants of systems are used in the same game. Objective. Systematize the theories related to the evolution of game systems in football and their relationship with the optimization of sports performance. Methodology. The research was carried out using a descriptive, non-experimental methodology, supported by the use of theoretical methods and documentary review; allowing the RSL (Systematic Literature Review) to be carried out in a time range between 2000 and 2020. To obtain quality information, a logical order was followed, which included the planning, analysis and evaluation of the results and findings mainly found in databases and high impact scientific articles preceded by the establishment of the inclusion and exclusion criteria determined, under the determination of the search criteria: game systems "," soccer "," sport " evolution. Results. 1. The importance, relevance and timeliness of the investigated topic is determined. 2. The variability and complexity of the game systems in football are not only related to the position that the players occupy within the field, it is a complex, deep process, with multiple views and dimensions. Tactical learning through different game strategies requires a solid cognitive development on the part of the participating footballers in such a way that it facilitates the motor application of what has been learned. Conclusions. The importance and timeliness of the subject is systematized, showing the need to continue deepening it, in order to provide studies that allow to show more intentionally the relationship between the different game systems and optimal sports performance.

The single-family houses in Girón, a canton located in the south of the province of Azuay, reveals the lack of hygrothermal performance studies in the design process that achieve successful internal thermal comfort conditions for the users; scenario that falls into poor indoor environmental quality of life. Through the thermal equilibrium, applying the heat balance equation, the research aims to determine the level of comfort or discomfort that the user experiences in the different the single-family house inner spaces. A qualitative research, starting at the exploratory level, with non-probabilistic sampling and the application of surveys, allows to obtain Girón population data. Heat balance calculations reveals if whether people are in comfort or in discomfort. The results exhibit that there are several factors which ward off the house users from being within the comfort zone; accordingly, it evidences the importance of the thermal balance analysis, which opens a wide range of possible recommendations that will allow reaching the expected levels comfort.