A low-level river crossing is an economic means of providing access for lower-order roads during high-frequency flood events. Conventionally, culverts are employed to enable the flow to traverse the road, albeit with allowance for overtopping. This overtopping flow from the approach roads, however, possesses the potential to cause erosion of the downstream embankment, thereby jeopardising the foundational integrity of the structure. A physical modelling study was undertaken to investigate the hydraulic performance of stepped chutes in terms of flow patterns, air-water flow properties, and energy dissipation. Various types of stepped chutes were investigated, namely horizontal steps with a chute wall, horizontal steps without a chute wall but with riprap placed directly downstream of each chute, step-inclined steps (backward sloping), steps with pooled cascades, and steps with baffle blocks. Notably, chutes with horizontal steps were the most efficient configuration in terms of relative energy dissipation. Furthermore, this research culminated in the formulation of a new regression formula to establish a quantifiable relationship between the required step length and the overflow depth and discharge, thereby offering a valuable tool for design purposes.

ABSTRACT The study was carried out at the Tío Pedro farm in the municipality of Venezuela, in the province of Ciego de Ávila, with the objective of proposing mathematical models to estimate the hydraulic parameters of a pumping system using the furrow irrigation technique for the cultivation of black bean. The results showed expected fluctuations in hydraulic parameters such as flow rate, head, hydraulic power, pumping time, and pumped volume. Functional relationships were found between flow and pumping head, as well as between hydraulic power, flow and pumping head. These ratios can improve pump system performance, save energy, and increase pump efficiency. In addition, functions were developed to predict the characteristic curves of the load, the efficiency of the pump and the system in general. These results can improve energy efficiency and water management in agriculture.

RESUMEN El estudio se realizó en la finca Tío Pedro en el municipio de Venezuela, en la provincia de Ciego de Ávila, tuvo como objetivo proponer modelos matemáticos para estimar los parámetros hidráulicos de un sistema de bombeo utilizando la técnica de riego por surcos para el cultivo del frijol negro. Los resultados mostraron fluctuaciones esperadas en los parámetros hidráulicos como caudal, carga, potencia hidráulica, tiempo de bombeo y volumen bombeado. Se encontraron relaciones funcionales entre el caudal y la carga de bombeo, así como entre la potencia hidráulica, el caudal y la carga de bombeo. Estas relaciones pueden mejorar el funcionamiento del sistema de bombeo, ahorrar energía y aumentar la eficiencia de la bomba. Además, se desarrollaron funciones para predecir las curvas características de la carga, la eficiencia de la bomba y del sistema en general. Estos resultados pueden mejorar la eficiencia energética y la gestión del agua en la agricultura.

ABSTRACT The energy efficiency of irrigation systems is an aspect of great importance in all design and management processes; For this reason, an investigation was carried out in the "Tío Pedro" farm located in the municipality of Venezuela, Ciego de Ávila province during the years 2021 and 2022 with the objective of estimating the general energy yield in the furrow irrigation system. During this period, the pump unit offers the following average operating regime: pump flow rate of 61.1 L s-1; pumping time of 2,8 hours and pumping head of 18.2 m. This behavior reduces a hydraulic power of 10.9 kW and a pump efficiency of 85.2%. The energy supplied in pumping was 429.4 kWh and the energy absorbed in the evaluated period was 631.9 kWh. In relation to the energy parameters of the system, an energy balance of the supply of 7,4 m was obtained; a system energy load index of 15.2 m; an energy efficiency of the pumping of 68.2% (excellent) and a general energy efficiency of the system of 34.0% (normal).

RESUMEN La eficiencia energética de los sistemas de riego es un aspecto de gran importancia en todos los procesos de diseño y manejo; por este motivo se desarrolló una investigación en la finca “Tío Pedro” ubicada en el municipio de Venezuela, provincia Ciego de Ávila durante los años 2021 y 2022 con el objetivo de estimar el rendimiento energético general en el sistema de riego por surcos. Durante este periodo la unidad de bombeo funcionó con el siguiente régimen de operación promedio: caudal de bombeo de 61,1 L s-1; tiempo de bombeo de 2,8 horas y carga de bombeo de 18,2 m. Este comportamiento determinó una potencia hidráulica de 10,9 kW y rendimiento de la bomba de 85,2%. La energía suministrada en el bombeo fue de 429,4 kWh y la energía absorbida en el periodo evaluado de 631,9 kWh. En relación con los parámetros energéticos del sistema se obtuvo un balance energético del suministro de 7,4 m; un índice de carga energética del sistema de 15,2 m; un rendimiento energético del bombeo de 68,2% (excelente) y un rendimiento energético general del sistema de 34,0% (normal).

The present research used a combination of experimental and numerical methods to investigate energy dissipation blocks of different heights placed downstream of a sluice gate in an open channel flow. Numerical model simulations were performed using a 3D computational fluid dynamics (CFD) technique, using the Reynolds-averaged Navier-Stokes (RANS) equations with the volume of fluid (VOF) and k-ε turbulence models. The accuracy of the numerical model and the grid sensitivity was assessed according to a recommended procedure in the literature. Different hydraulic and geometry conditions were investigated to understand the energy dissipation behaviour of the blocks. The hydrodynamic effects of different block spacings, heights and configurations were analysed by means of CFD simulations. The results show that the variable size blocks have a high energy dissipation efficiency in sluice gate flows, particularly at high Froude numbers. The energy dissipation efficiency of the blocks downstream of a sluice gate can reach up to 55% for high discharges (Q = 35 L/s). Interestingly, the energy dissipation performance of small gate openings exceeds that of large gate openings, reaching a peak efficiency of 40% for the same discharge. In addition, the block spacing has a minimal effect on the energy dissipation, while smaller block spacing results in a smoother water surface profile.

Abstract Compaction is a fundamental step in pervious concrete production and affects its mechanical and hydraulic properties. In this study, two pervious concrete mixtures were compacted with three different energies, distributed in two and three layers. The effects on porosity, mechanical strength and hydraulic conductivity were evaluated. The increase in compaction energy resulted in a proportional reduction in porosity. Increases in compressive strength from 17 to 36% were observed. However, permeability reduced proportionally, with decreases of 0.2 to 0.4 cm/s. The three-layer compaction resulted in a more homogeneous vertical distribution of porosity when compared to the two-layer compaction. Although the aggregate/cement ratio was the most influential parameter, the compaction energy should also be considered in the pervious concrete mixture design. While increasing the compaction energy enhances the mechanical strength of pervious concrete, excessive compaction may cause the fracture of the coarse aggregate, reducing its mechanical and hydraulic performance. Thus, for each mixture an optimum compaction energy can be defined to maximize the performance of pervious concrete. properties study energies layers evaluated 1 36 observed However proportionally 02 0 2 0. 04 4 cms cm s cm/s threelayer layer twolayer aggregatecement aggregate cement parameter design Thus 3

Resumo A compactação é uma etapa fundamental na produção do concreto permeável e afeta suas propriedades mecânicas e hidráulicas. Neste estudo, duas misturas de concreto permeável foram compactadas com três níveis de energia, distribuídas em duas e três camadas. O efeito na porosidade, resistência mecânica e condutividade hidráulica foi analisado. O aumento da energia de compactação resultou em uma redução proporcional da porosidade. Consequentemente, um aumento da resistência à compressão de 17 a 36% foi observado. No entanto, a permeabilidade reduziu proporcionalmente, com perdas de 0,2 a 0,4 cm/s. A compactação do concreto em três camadas resultou em um perfil de distribuição vertical da porosidade mais homogêneo quando comparado à compactação em duas camadas. Embora a relação agregado/cimento tenha sido o parâmetro mais influente, a energia de compactação também deve ser levada em consideração na dosagem do concreto permeável. Embora o aumento da energia de compactação melhore a resistência mecânica do concreto permeável, a compactação excessiva pode causar a fratura do agregado graúdo, reduzindo o seu desempenho mecânico e hidráulico. Dessa forma, para cada mistura uma energia de compactação ótima pode ser definida para maximizar o desempenho do material. hidráulicas estudo analisado Consequentemente 1 36 observado entanto proporcionalmente 02 0 2 0, 04 4 cms cm s cm/s agregadocimento cimento influente graúdo hidráulico forma material 3

Abstract Exploring the natural complementarity that exists between renewables is pivotal for optimizing clean electricity generation. Quantifying this complementarity can enhance electrical planning, reducing waste of natural resources and guiding investment decisions more effectively. To quantify the complementarity existing in Brazilian river basins, a methodology was proposed. Data on influent natural energy, irradiance, and wind speed are analyzed using Python. Through a comprehensive process, the most suitable correlation coefficient is identified. The subsequent calculation of coefficients for specific source combinations and periods, as well as the application of the Innovative Trend Analysis methodology, allow an understanding of the existing complementarity dynamics. The methodology was applied to the Capivari River basin, located in the state of Paraná, which included a monthly analysis of complementarity between hydraulic generation with wind and photovoltaic sources from June 2016 to April 2024. There was no discrepancy in the interpretations of the results obtained for Spearman’s Rho and Kendall's Tau, although the magnitude of Kendall's Tau is, on average, 30% lower for the combination of photovoltaic and hydraulic and 49% for the combination of wind and hydraulic. The combination of wind and hydraulics exhibited seasonal complementarity, demonstrating lesser advantages compared to photovoltaic generation, with around 61% of the acquired values of Spearman’s Rho being negative, approximately 28% of which were negligible. This percentage is lower than the over 82% of negative values observed for the photovoltaic and hydraulic combination, of which 12% are negligible. The results are consistent with the literature and validate the proposed methodology. planning effectively basins energy irradiance Python process identified periods dynamics basin Paraná 201 2024 Spearmans Spearman s Kendalls Kendall average 30 49 61 28 negligible 82 12 20 202 3 4 6 2 8 1

Abstract Examples of upscaling phenomena with experimental techniques are presented and discussed within the framework of compacted soils for hydraulic and environmental earthworks and engineered barriers for the energy sector. A series of laboratory experiments at different scales are presented and interpreted to focus on the need for experimental upscaling in compacted soils since distinctive behavioural features can only be detected at specific length scales. Permeability results on fine-grained soils and artificially prepared sand/bentonite mixture at different scales will be discussed with microstructural tests regarding ‘dry’ or ‘wet side’ compaction, element and mock-up tests on compacted soils in the laboratory, and field tests on a compacted trial embankment and demonstration test to explore anisotropic and heterogeneous features. The presented examples will help to motivate new experimental research subjects and promote experimental protocols at different scales ranging from mm-scale (micro), cm-scale element tests, dm-scale mock-ups and m-scale (trial/demonstration tests) to help understand and approach some fundamental questions observed at the application scale of compacted soils. sector finegrained fine grained sandbentonite sand bentonite ‘dry dry wet side compaction mockup mock up mmscale mm micro, micro , (micro) cmscale cm dmscale dm mockups ups mscale m trial/demonstration trialdemonstration (micro

ABSTRACT Fruit and vegetable waste (FVW) are sugar-rich substrates that can result in hydrogen through dark fermentation. The success of dark fermentation depends on changing operation parameters, which vary based on the characteristics of the substrate. This study aimed to determine how FVW from a central horticultural wholesaler should be fermented to produce the maximum amount of hydrogen. The following goals were listed as determining the pre-treatment method (chemical, thermic, and acid) for brewery sludge and evaluating the fermentation of the liquid fraction of FVW in an anaerobic structured bed reactor (AnSTBR). The AnSTBR operation started with sucrose as substrate at a hydraulic retention time (HRT) of 6 h. Then, the sucrose was gradually replaced by FVW at the HRT of 6 h. The FVW was fed as the sole carbon source (5 g COD/L) at HRTs of 6, 12, and 3 h for at least 20 days on each condition. The heat treatment resulted in the highest cumulative hydrogen production and hydrogen production rate (HPR) (90 mL H2 and 6.6 mL H2/h). In the AnSTBR operation, the highest values of HPR were observed at 6 h (2094 L H2/m3 reactor.d). The attempt to decrease the HRT to 3 h caused a reduction in the HPR to 216 L H2/m3 reactor.d. It is highly encouraging the increase of the organic loading rate and the use of co-fermentation, aiming to reduce the size of the reactor and water expended on dilution by increasing substrate concentration in future studies. (FVW sugarrich sugar rich parameters pretreatment pre chemical, chemical (chemical thermic acid AnSTBR. . (AnSTBR) (HRT Then 5 ( COD/L CODL COD 12 2 condition (HPR 90 (9 H 66 6. H2/h. H2h Hh H2/h H2/h) 2094 (209 H2m3 Hm m3 m H2/m reactord reactor.d d reactor.d) 21 cofermentation, cofermentation co fermentation, co-fermentation studies (AnSTBR 1 9 209 (20 H2m (2

ABSTRACT Resíduos de frutas e vegetais (RFV) são substratos ricos em açúcar que podem ser usados para produzir hidrogênio por meio da fermentação escura. O sucesso dessa fermentação depende dos parâmetros de operação, que variam com base nas características do substrato. Este estudo teve como objetivo determinar como os RFV de uma central de abastecimento de hortifrutigrangeiros devem ser fermentados para produzir a quantidade máxima de hidrogênio. Os seguintes objetivos foram listados: determinar o método de pré-tratamento (químico, térmico e ácido) para lodo de cervejaria e avaliar a fermentação da fração líquida dos RFV em reator anaeróbio de leito estruturado (AnSTBR). A operação do AnSTBR começou com sacarose como substrato operado com tempo de detenção hidráulica (TDH) de 6 horas. Em seguida, a sacarose foi gradualmente substituída por RFV usando TDH de 6 horas. O RFV foi usado como a única fonte de carbono (5 g DQO/L) com TDHs de 6, 12 e 3 horas por pelo menos 20 dias em cada condição. O tratamento térmico resultou na maior produção cumulativa de hidrogênio e taxa de produção de hidrogênio (TPH) (90 mL H2 e 6,6 mL H2/h). Na operação do AnSTBR, os maiores valores de TPH foram observados em 6 horas (2.094 L H2/m3 reator.d). A tentativa de reduzir o TDH para 3 horas causou uma redução no TPH para 216 L H2/m3 reator.d. É altamente recomendado o aumento da taxa de carga orgânica volumétrica e o uso de co-fermentação, visando reduzir o tamanho do reator e a água gasta na diluição, aumentando a concentração do substrato em estudos futuros. (RFV escura listados prétratamento pré químico, químico (químico ácido AnSTBR. . (AnSTBR) (TDH seguida 5 ( DQO/L DQOL DQO 1 2 condição (TPH 90 (9 H 66 H2/h. H2h Hh H2/h h H2/h) 2.094 2094 094 (2.09 H2m3 Hm m3 m H2/m reatord reator.d d reator.d) 21 cofermentação, cofermentação co fermentação, co-fermentação diluição futuros (AnSTBR 9 2.09 209 09 (2.0 H2m 2.0 0 (2. 2. (2

Abstract In the Carajás Province, many Au and Cu deposits are hosted in Archean metabasic rocks belonging to the Itacaiúnas Supergroup. These metabasic rocks underwent seawater metamorphism of greenschist facies concomitantly to the volcanic activity and banded iron deposition. In the Carajás Province, synkinematic granite magmatism occurred at ca. 2.75 Ga as represented by the Estrela, Serra do Rabo, Planalto, and Igarapé Gelado granites. Emplacement at relatively shallow levels created thermal aureoles of albite-epidote hornfels to hornblende hornfels facies. Metabasic xenoliths show assemblages of hornblende hornfels. Regional stresses and lateral expansion of the syntectonic granites promoted high-temperature low-pressure metamorphism and ductile deformation in the host metabasic rocks. Dehydration reactions increased the fluid pressure permitting hydraulic fracturing and veining in the metabasaltic rocks. These conditions increased the kinetic energy of minerals so that pressure solution and dissolution of minerals were enhanced. The material transfer caused by the advective flow of supersaturated fluids leads to the formation of amphibole-bearing veins and subordinate quartz-bearing and plagioclase-bearing veins. Progressive reactions during thermal metamorphism promoted the replacement of actinolite to ferropargasite/edenite and Na-plagioclase to Ca-plagioclase. Silica produced in these reactions was transported by fluids and deposited in veins that crosscut the amphibolites. Province Supergroup deposition ca 275 2 75 2.7 Estrela Rabo Planalto albiteepidote albite epidote hightemperature high temperature lowpressure low enhanced amphibolebearing amphibole bearing quartzbearing quartz plagioclasebearing plagioclase ferropargasiteedenite ferropargasite edenite Naplagioclase Na Caplagioclase. Caplagioclase Ca plagioclase. Ca-plagioclase amphibolites 27 7 2.

Abstract Recently, solar energy has become most favorable source of energy. It is sustainable and environmentally friendly, and one of the most common application of solar energy is the solar water heater, which has a wide commercial and domestic applications. To enhance the performance of this device, many modifications are recommended. The enhancements may involve changes in pipe shape or materials or in absorber plate manufacturing, or sometimes by using a thermal storage tank to maintain heating. In this study, a variable cross-sectional area pipe is used to enhance heat transfer. Firstly, the vertical length is increased at the outlet to 1.2-1.8 ratios, while the horizontal sides remain constant. Then, for the same ratio, the horizontal sides are varied while the vertical sides remain constant. Finally, both the vertical and horizontal sides are increase. A three-dimensional numerical analysis is used to investigate the conjugated heat transfer and the flow characteristics in the pipe under study for each case. FLUENT ANSYS 17.2 is used to achieve this analysis using finite volume technique. Energy, Navier-Stokes, and continuity equations are solved at constant heat flux condition for a range of Reynolds numbers from 100 to 500. The hydraulic-thermal function ε is adopted in this study. The best increase in ε is 48%, achieved in the case of changes to both vertical and horizontal dimensions at a ratio of 1.8. The lowest percentage of decrease in pressure drop is 9.7%, and the highest temperature difference found is and 45.5% for the same case when compared with the uniform case for Reynolds number of 100. The present work is validated with another study adopting Shah’s empirical relation with a very good agreement. Recently friendly heater applications device recommended manufacturing heating crosssectional cross sectional Firstly 1.21.8 1218 1.2 1.8 1 2 8 1.2-1. ratios Then Finally threedimensional three dimensional 172 17 17. technique Energy NavierStokes, NavierStokes Navier Stokes, Stokes Navier-Stokes 10 500 hydraulicthermal hydraulic 48 48% 18 97 9 7 9.7% 455 45 5 45.5 Shahs Shah s agreement 21 1.21. 121 12 1. 1.2-1 50 4 9.7 45. 1.21 1.2- 9.

ABSTRACT The use of irrigation enhances productivity, reduces vulnerability to drought and climate variation, and boosts agricultural production. This study aimed to verify the economic viability of implementing center pivot irrigation for corn, cowpea, and soybean crops. A 50-hectare area irrigated by a center pivot system was considered, simulating rotational cultivation in the region of Paraíso das Águas, MS. The historical average ET0 of 8 mm day-1 for the region was used for project design and irrigation management. Financial indicators were calculated based on regional technical cultivation coefficients. Overall, 62.1% of the total production costs for the corn, cowpea, and soybean agricultural system were allocated to preparation, planting, cultural practices, and harvesting, while 34.8% were allocated to irrigation (investment in hydraulic equipment and infrastructure, energy, depreciation, and maintenance). The net present value (NPV) for corn, cowpea, and soybean crops were $72.07, $359.68, and $410.59 per hectare, respectively, averaging $842.34 per hectare per year. This profitability provides gains for producers, generating employment and regional development. The implementation of a 50-hectare center pivot irrigation system is economically feasible for cultivating corn, cowpea, and soybeans, considering a 4-year and 9-month return on capital investment under the study conditions. productivity variation corn cowpea 50hectare 50 considered Águas MS ET day1 day 1 day- management coefficients Overall 621 62 62.1 preparation planting practices harvesting 348 34 34.8 infrastructure energy depreciation maintenance. maintenance . maintenance) NPV (NPV 7207 72 07 $72.07 35968 359 68 $359.68 41059 410 59 $410.5 respectively 84234 842 $842.3 year producers development soybeans 4year 4 9month month 9 conditions 5 6 62. 3 34. 720 7 0 $72.0 3596 35 $359.6 4105 41 $410. 8423 84 $842. $72. $359. $410 $842 $72 $359 $41 $84 $7 $35 $4 $8 $ $3

Abstract. - In Mexico the development of remote laboratories is incipient, in 2020 the National Council of Humanities, Sciences, and Technologies (CONAHCYT) created a network of virtual laboratories with nine of its public research centers in order to create a virtual space that enables the development of experimental and research activities in a distance modality. However, access to virtual laboratories is limited only to its members, and the platforms are still under development. With this motivation, this article presents a multi-institutional project for the design, development, and implementation of a pico-hydraulic system for small-scale power generation for teaching and training purposes with the aim of responding to the current need for distance or virtual teaching of practical knowledge due to the coronavirus disease (COVID‑19) caused by the SARS-CoV-2 virus. For the development of the system, technological innovation tools (QFD, TRIZ) were used, with which the design requirements were obtained considering the users (students and teachers) and the renewable energy-related competence of the curricula. Finally, the satisfaction of the users (students and teachers) with the use of the designed system shows the advantage of including it as part of the practical activities of the subjects to improve the development of power generation, transformation, and transmission system projects.

Resumen. - En México el desarrollo de laboratorios remotos es incipiente, en 2020 el Consejo Nacional de Humanidades, Ciencias y Tecnologías (CONAHCYT) creó una red de laboratorios virtuales con nueve de sus centros públicos de investigación con el fin de crear un espacio virtual que permita el desarrollo de actividades experimentales y de investigación en la modalidad a distancia. Sin embargo, el acceso a los laboratorios virtuales está limitado sólo a sus miembros y las plataformas aún están en desarrollo. Con esta motivación este artículo presenta un proyecto multi-institucional para el diseño, desarrollo e implementación de un sistema pico-hidráulico para la generación de energía a pequeña escala con fines de enseñanza y capacitación con el objetivo de responder a la necesidad actual de enseñanza a distancia o virtual de conocimientos prácticos debido a la enfermedad coronavirus (COVID-19) causada por el virus SARS-CoV-2. Para el desarrollo del sistema se utilizaron herramientas de innovación tecnológica (QFD, TRIZ), con las que se obtuvieron los requisitos de diseño teniendo en cuenta los usuarios (alumnos y profesores) y las competencias relacionadas con las energías renovables de los planes de estudio. Finalmente, la satisfacción de los usuarios (alumnos y profesores) sobre el uso del sistema diseñado muestra la ventaja de incluirlo como parte de las actividades prácticas de las asignaturas para mejorar el desarrollo de proyectos de sistemas de generación, transformación y transmisión de energía.

South Africa is in a critical power situation and is in dire need of additional generation capacity. Thus, renewable energy sources such as wind, solar and hydropower should be evaluated to identify high-potential and cost-effective sites. Rivers in South Africa, as a water-scarce country, are already heavily impounded, meaning that there are limited sites available for conventional hydropower generation. Instead, novel solutions such as retrofitting hydropower installations to existing infrastructure, like existing dams, are required. To estimate the retrofit hydropower potential at dams, a set of five tools was developed using Python 3, known as the University of Pretoria Retrofit Hydropower Evaluation Software (UP-RHES). The UP-RHES screens potential sites where historic flow records are available, then downloads the required flow records from the national database and performs a first-order hydraulic assessment of the site, as well as a first-order life cycle cost analysis. By applying the UP-RHES to 118 dams operated by the Department of Water and Sanitation (DWS), it was found that a total estimated hydropower potential of 128 MW with an annual energy output of between 385 and 469 GWh exists at South African dams. The Vaal, Pongolapoort, Goedertrouw and Blyderivierpoort Dams were found to be feasible sites with a combined capacity of 77 GWh/annum.

Resumen Este trabajo analiza la influencia que la dificultad de acceso a fuentes energéticas competitivas tuvo en el desarrollo de Argentina, en el período de la organización nacional. Era el período del carbón, motor de la revolución industrial y base del dominio global de Inglaterra, mineral del que Argentina carecía, a diferencia de países en otros sentidos análogos, como Australia y Chile, donde la explotación impulsó la industrialización. Las importaciones de carbón inglés, una carga sobre el balance externo de la economía argentina, se integraron fluidamente al modelo y atenuaron eventuales medidas proteccionistas. Las clases dirigentes no fueron indiferentes al tema y se han identificado iniciativas, públicas y de particulares, tendientes al abastecimiento del recurso, que fracasaron por carencias estructurales y las condiciones geológicas adversas. Cuando la electricidad se incorporó como factor de transformación de la producción, la dependencia del carbón importado se agravó, porque los núcleos de producción se encontraban alejados de los ríos de montaña, limitando el aporte de la generación hidráulica. Se estudia también la primera explotación industrial de petróleo en el territorio, que fracasó debido a las limitaciones estructurales características del modelo. A pesar de la visión y de los esfuerzos, Argentina, país de vocación industrialista, atravesó el período como importador de prácticamente la totalidad de la energía que necesitaba.

Abstract The influence of limited access to competitive energy sources on the development of Argentina in the period of national organization is analyzed in this paper. It is the period of coal, power source of the industrial revolution and the basis of England's global dominance, a mineral that Argentina lacks, unlike countries -in other senses analogous- such as Australia and Chile, where coal mining fostered industrialization. British coal imports, a burden on the external balance of the Argentine economy, were fluently integrated into the model and attenuated eventual protectionist measures. Initiatives have been identified showing that local ruling classes were not indifferent to the issue and, both in public and private sectors, aimed at supplying the resource. Despite the efforts, projects failed due to structural deficiencies and adverse geological conditions. When electricity is incorporated as a factor for transforming production, dependence on imported coal increased since the production concentrates in the plains, far from mountain rivers, thus limiting the contribution of hydraulic generation. The first industrial exploitation of oil in the territory, which failed due to the structural limitations of the model, is also studied. Despite the vision and the efforts, Argentina, a country with industrialist aspirations, went through the period as an importer of practically all the energy it needed.

Abstract In this work, the principle of hydroelectric generation, used on a large scale in our country, is applied. The built system represents a didactic laboratory tool in teaching courses on renewable energies. The objective of this article is the construction of a didactic hydraulic micro generator that allows to take advantage of the kinetic energy of water to produce electrical energy. In addition, having said system in an educational institution helps to teach concepts of renewable energies such as micro-hydraulics and promote its applications in rural areas through projects related to society. Important design aspects such as power generation, use of the Archimedes screw model, supply of water resources, cost of materials for processing, installation of the generator, among others, have been considered. This proposal offers a low-cost educational solution that is easy to reproduce, which generates a maximum power of 8(W) with a flow rate of 10(l/s), which allows supplying a certain electrical demand, mainly for lighting. Through a model validated in the laboratory thanks to the removable system that must be used in a real environment, tests were carried out using a water storage tank and a pump. With these results it is concluded that the built system takes advantage of a reduced water flow to produce clean and renewable energy.

Resumen En este trabajo se aplica el principio de generación hidroeléctrica, utilizado a gran escala en nuestro país. El sistema construido representa una herramienta didáctica de laboratorio en los cursos de docencia sobre energías renovables. El objetivo de este artículo es la construcción de un microgenerador hidráulico de carácter didáctico que permita aprovechar la energía cinética del agua para la producción de energía eléctrica. Además, disponer dicho sistema en una institución educativa ayuda a enseñar conceptos de energías renovables como la microhidráulica y potenciar sus aplicaciones en zonas rurales a través de proyectos de vinculación con la sociedad. Se han considerado aspectos de diseño importantes como potencia de generación, uso del modelo tornillo de Arquímedes, suministro del recurso hídrico, costo de materiales para la elaboración, instalación del generador, entre otros. Esta propuesta ofrece una solución didáctica de bajo costo fácil de reproducir, que genera una potencia máxima de 8 (W) con un caudal de 10 (l/s), lo que permite abastecer una determinada demanda eléctrica, principalmente de iluminación. A través de un modelo validado en laboratorio gracias al sistema desmontable que posee para ser utilizado en un entorno real, se realizaron pruebas, utilizando un tanque de almacenamiento de agua y una bomba. Con estos resultados se concluye que el sistema construido aprovecha un caudal de agua reducido para producir energía limpia y renovable.