The flipped classroom methodology combines theoretical and practical learning by encouraging students to work with theoretical content at home and practical in-class activities. The purpose of this study is to provide an active learning approach combining flipped classroom and the incorporation of hands-on experimentation with remote laboratories to improve student engagement and performance, especially in complex subjects or engineering areas, where traditional lecture-based methods are not sufficient. To evaluate the effectiveness of this active learning approach, we conducted a pilot study with a selected group of students, using a combination of predictive and post-experimentation assessments and feedback mechanisms. In the pilot, hands-on experimentation was carried out using our newly developed photovoltaic (PV) solar remote laboratory, to improve the understanding of the influence of altitude on PV energy efficiency, which cannot be achieved with simulations or with a real laboratory deployed in a single location. The results showed a significant improvement in the post-experimentation scores from 50% average to 79% and high student satisfaction with the learning experience. The findings of this pilot study provide valuable insights for the future adoption of similar methodologies and the implementation of the proposed approach.

Lighting engineering education often lacks hands-on tools for students to learn street lighting systems, such as measuring light intensity, optimizing energy use, or validating compliance with standards. Traditional approaches rely on abstract models or simulation software, which prioritize design over pedagogy. To address this gap, we developed a hybrid remote lab combining real-time and ultra-concurrent approaches. The lab platform includes three core activities: (1) real-time control of a single street light (adjusting light intensity, capturing light data via light sensors mesh, and visualizing light distribution), (2) real-time monitoring of five street lights in a real-world campus setup to evaluate compliance with standards, and (3) ultra-concurrent analysis of pre-recorded datasets to study light behavior in different scenarios. The platform uses a web interface connected to ESP32 micro-controllers on AC, DC, and inverter-based street lights. Data is transmitted via MQTT, and a booking system manages access for real-time experiments. The remote lab aims to help students connect theory with practice, improving their ability to predict, analyze, and optimize lighting systems. The hybrid approach supports diverse learning styles by combining hands-on control, data analysis, and real-world observation.

This paper presents the design, implementation, and evaluation of remote laboratories deployed in Bolivia that enable international access to photovoltaic (PV) module characterization. Through an internet-based platform, students from Bordeaux-France performed experiments on real PV panels, investigating key parameters including current-voltage (I-V) and power-voltage (P-V) curves, the effect of tilt angle and orientation, and the influence of light intensity. A unique feature of the system is the installation of identical PV setups at different altitudes, providing insights into the environmental impact on solar panel efficiency. Usability and learner attitudes were assessed using standardized instruments such as the USE Questionnaire and a tailored survey. The results indicate high levels of satisfaction, ease of use, and positive learning outcomes, affirming the potential of remote laboratories to enhance photovoltaic education. These findings support the continued deployment and expansion of remote labs as an effective educational tool, smoothing the path for future innovations in intercontinental collaborative learning.

Digital transformation in education, particularly in Latin America, faces significant challenges due to the lack of standardized academic credit systems across universities. The EU-BEGP Project aims to address some of the challenges by developing a unified qualification framework that aligns with the European Credit Transfer and Accumulation System (ECTS) and an earlier proposed “Latin American Reference Credit” (CLAR) system. This paper presents the “EXPLORE Energy Digital Academy” (EEDA) concept, which supports global collaboration in the co-creation of digital learning materials, emphasizing quality assurance and innovative, student-centered educational models that are expanded into Latin America. This is done through the EU-sponsored “EU-BEGP” Project which involves partners from both Latin America and Europe and seeks to modernize courses and programs in the energy sector through digital tools and resources, while also proposing solutions for a standardized academic credit system that facilitates the recognition of qualifications across regions. This initiative is crucial for fostering educational collaboration and ensuring that digital education meets the diverse needs of students in emerging regions. The paper describes the background of such collaboration and focuses upon the necessity of (1) appropriate academic metadata, (2) educational quality process and (3) credit transfers between partners.

In the context of online education, remote laboratories play a crucial role in practical application of theoretical knowledge. Even though there are some remote laboratories to study the solar efficiency of photovoltaic (PV) panels, they are limited either to a single specific location or restricted to simulated conditions. In this paper, we focus on understanding the behavior of PV solar panels under diverse conditions, including altitude, Ultraviolet-A influence, temperature, and solar radiation, which are factors that cannot be accurately simulated and require real-world experimentation. We present the development of a distributed PV Solar Remote Lab deployed at three different cities and altitudes, emphasizing Internet of Things (IoT) technology for real-time data collection and experiment control. Our PV Solar Remote Lab web platform incorporates a specialized current-voltage (I-V) tracer system for accurate efficiency calculations. We obtained encouraging preliminary results on altitude's influence on PV efficiency. Our remote lab implementation leverages IoT, providing valuable insights into the impact of altitude on PV efficiency and promoting a deeper understanding of solar energy systems. We also contribute to online education by offering a user-friendly platform for practical PV experiments in diverse real-world conditions.

The use of remote laboratories nowadays offers multiple advantages like accessibility, cost-effectiveness, flexibility, and safety. However, ensuring a secure and uniform interface for a remote laboratory remains a challenge. In this paper, we present the development of the Real-Time Remote Lab Bridge Server (or simply BridgeServer), a tiny web server that provides secure and transparent access to remote labs, without the necessity of a third-party software or password sharing. Its key features are the serve of a web-based remote desktop session created with locally stored credentials, secure file downloads, session time administration, and automated access control thanks to the validation with an Application Programming Interface (API) of a Booking System. This solution maintains control, employs consistent credentials for all users, and prevents direct access to lab equipment control software. We provide a real-world use case that exemplifies the flexibility of our solution simplifying access to a third-party software remote lab without any need for code modifications. We successfully solved access challenges in an international network of real-time remote labs deployed in Latin America, Asia, Africa, and Europe, particularly for Windows-based lab control software.

Remote Laboratories are an important tool for digital education, allowing learners worldwide to get a close to real laboratory experimental experience. There is a large body of research in online and Remote Labs, but little attention has been given to defining a service ensuring exclusive access to remote laboratory equipment. Most Remote Labs do not check for exclusive access, thus allowing simultaneous users to interfere with each other. As such, existing systems are mostly for internal institutional use, not for global collaborative use with users from different institutions, countries, and time zones. This paper describes Book4RLab, a new general-purpose Booking System for Remote Labs, providing a secure and flexible interface for any Remote Lab to handle individual slot reservations. The Booking System requires only a small modification of existing server and client-side software. We describe the overall architecture and the Representational State Transfer (REST) Application Programming Interface (API) to use the Booking System. As a case study, we describe its use in the context of the EXPLORE Energy Digital Academy (EEDA), a growing international network for open digital education programs in the energy area, where 14 Remote Labs are under development in 4 countries.

Instrument calibration is a critical but time-consuming process in many scientific fields. In this paper, we present an approach using recurrent neural networks (RNNs) for automatically detecting reference lines required to calibrate a spectrometer with well-known wavelengths of mercury and neon spectra. RNNs are a type of neural network that is best suited for processing sequential data. We collect a dataset of spectral images by taking images with cameras of different resolutions to train the neural network. Moreover, we prove that RNNs can learn to predict spectra lines in the calibration process with high precision. We match spectrometer measurements to their corresponding wavelengths by fitting a polynomial with these predicted reference lines. We validate our method using a 3D-printed spectrometer and compare the results with the NIST Atomic Spectra Database. The automatic selection of neon or mercury reference lines helps the calibration procedure to become faster, thus avoiding any manual selection. Our proposed technique is suitable for spectrometry applications where the speed is critical and the calibration process needs to be performed frequently.

Laser-Induced Breakdown Spectroscopy (LIBS) is a widely used non-destructive analysis technique, which is however costly. In this paper we present the development of a low-cost 3D-printed portable LIBS system designed and built with a Technology Readiness Level 5 (TRL 5), i.e., technology validated in a relevant environment. The proposed LIBS system is compact and includes a passive Q-switch Nd3+:YAG pulsed laser, a handheld measuring device, a power supply, an optical spectrometer and a processing software. The electronic control system guarantees a stable laser triggering, thanks to the use of optical connections (optocouplers) avoiding wired electrical connections of the circuits. In addition, we found the correct energy characteristics of the passive Q-switch regime, to generate a single laser pulse, thus making the system operate more efficiently. Our low-cost 3D-printed portable LIBS system was validated with several tests with real samples of atomic elements (i.e., lithium, copper, silver, gold and lead).

The Covid-19 pandemic has precipitated the digital transformation in education worldwide and has exposed weaknesses and limitations in laboratory and experimental activities, mainly in the field of engineering. This forced us to provide rapid answers through a change in practice in our renewable energy program, from a conventional hands-on classroom experiment to a remote spectrometry laboratory. In this context, using costly spectrometry equipment that was not adapted to be operated remotely, was not an option. In this paper we describe how we adapted our low-cost spectrometry technology (which is based on a 3D-printed mini-spectrometer and a smartphone) to deploy a remote laboratory as a rapid solution, due to the impossibility of using conventional and costly spectrometers, which work only for on-campus learning. This adaptation was helpful, not only to have several spectrometers available for a higher number of students, but also to allow teachers to prepare asynchronous activities that can be realized without their presence. We applied Internet of Things (IoT) technology for remotely controlling the experiments and used Machine Learning to automatically calibrate our low-cost smartphone spectrometer. We believe that such a low-cost spectrometry remote laboratory can benefit developing countries and enable the development of MOOC and MOOL type courses.

Fluorescence microscopy is an important tool for disease diagnosis, often requiring costly optical components, such as fluorescence filter cubes and high-power light sources. Due to its high cost, conventional fluorescence microscopy cannot be fully exploited in low-income settings. Smartphone-based fluorescence microscopy becomes an interesting low-cost alternative, but raises challenges in the optical system. We present the development of a low-cost inverted laser fluorescence microscope that uses a smartphone to visualize the fluorescence image of biological samples. Our fluorescence microscope uses a laser-based simplified optical filter system that provides analog optical filtering capabilities of a fluorescence filter cube. Firstly, we validated our inverted optical filtering by visualizing microbeads labeled with three different fluorescent compounds or fluorophores commonly used for disease diagnosis. Secondly, we validated the disease diagnosis capabilities by comparing the results of our device with those of a commercial fluorescence microscope. We successfully detected and visualized Trypanosoma cruzi parasites, responsible for the Chagas infectious disease and the presence of Antineutrophil cytoplasmic antibodies of the ANCA non-communicable autoimmune disease. The samples were labeled with the fluorescein isothiocyanate (FITC) fluorophore, one of the most commonly used fluorophores for disease diagnosis. Our device provides a 400× magnification and is at least one order of magnitude cheaper than conventional commercial fluorescence microscopes.

El agua subterránea es la principal fuente de consumo en muchos centros urbanos y áreas rurales de Bolivia, tal es el caso del Municipio de San Pedro ubicado en el departamento de Santa Cruz. El presente estudio se realizó con la Received 04 12 2021 Accepted 04 26 2020 Published 04 30 2021 Vol. 38, No.1, pp. 46-55, Ene./Abr.2021 Revista Boliviana de Química 38(1), 46-55, Jan./Apr. 2021 Bolivian Journal of Chemistry DOI: 10.34098/2078-3949.38.1.5 REVISTA BOLIVIANA DE QUÍMICA ISSN 0250-5460 Rev. Bol. Quim. Paper edition ISSN 2078-3949 Rev. boliv. quim. Electronic edition Lizangela Huallpara L. et al. RBQ Vol.38, No.1, pp. 46-55, 2021 Downloadable from: Revista Boliviana de Química. Volumen 38 Nº1. Año 2021 http://www.bolivianchemistryjournal.org, http://www.scribd.com/bolivianjournalofchemistry 47 Received 04 12 2021 38(1); Jan./Apr. 2021 Accepted 04 26 2021 Published 04 30 2021; DOI:10.34098/2078-3949.38.1.5 finalidad de determinar la calidad fisicoquímica del agua subterránea de consumo en 16 comunidades rurales ubicadas dentro del municipio de San Pedro. Los resultados mostraron valores de pH ligeramente alcalinos comprendidos entre 7,8 y 8,6 y la conductividad eléctrica mostró valores en un rango que va de 313,3 a 1189 µS/cm. Las aguas son predominantemente del tipo Na-HCO3 y contienen elevadas concentraciones de fluoruro (F- ) en un rango que va de 2,1 a 6,4 mg/L excediendo el valor máximo recomendado por la Organización Mundial para la Salud (OMS). Cálculos de índice de saturación (IS) muestran que la fase mineral que podría dar origen al elevado contenido de F- en agua es la [F-Apatita].

A practical low-cost treatment system of suitable capacity was developed in order to satisfy drinking water consumption needs of people living in small rural villages affected by arsenic contamination. The system is based on a semicircular section tubular photo-reactor which has been constructed, characterized and applied to the treatment of groundwater contaminated with As (V) by means of the solar oxidation and removal of arsenic (SORAS) technique, using ferrous and citrate salts. The solar concentrator was made from recyclable waste materials such as fluorescent lamp glass tubes and 6” PVC pipes cut in half and covered in aluminium foil. Solar radiation is concentrated to 2.8 times its natural intensity in the reactor. When compared to a fluorescent light glass tube alone and a 2-liter PET bottle, batch irradiation trials followed by controlled agitation (shear rate = 30 – 33 s-1; 20 min agitation period) revealed that the photo-reactor promotes the development of settleable floccules (Dp > 0.5 mm). c In the photo-reactor, the fluorescent lamp tube, and the PET bottle, the required irradiation times for floccule generation were 15, 25, and 60 minutes, respectively. Continuous flow investigations utilising a photo-reactor with a photo-collection area of 0.9 m2 and a hydraulic retention duration (equivalent to the irradiation period) of 15 minutes revealed that when the solution is agitated moderately, good settleability floccules form immediately (33 s-1). With a final concentration of 16.5 mg/L in decanted water, an As (V) removal efficiency of 98.36 percent was achieved. According to these findings, at UVA irradiation intensities of 50-70 W/m2, the photo-reactor can treat roughly 130 L/m2 in a 5-hour period. This daily capacity can supply safe water to a 4 - person family at a consumption rate of 30-35 L/person/day, a typical value in rural areas in the Bolivian Altiplano.

La presencia de elevadas concentraciones de arsénico encontradas en el agua de consumo de dos sitios geográficamente distantes en Bolivia, ha requerido el diseño, la construcción y la implementación de un sistema de remoción de arsénico para así obtener agua más segura para su consumo. Uno de los sitios se encuentra en una unidad educativa de la zona periurbana de la ciudad de Cochabamba y el otro en una escuela rural en la población de Quillacas en el departamento de Oruro dentro del área del Altiplano boliviano. El sistema consta de dos procesos de remoción de arsénico que funcionan en serie: i) el proceso RAOS que requiere una etapa de aireación y dosificación con sulfato ferroso y citrato de sodio automáticamente controlado con el flujo de agua, 6 fotoreactores provistos de tubos de acrílico de alta transmitancia emplazados en colectores solares tipo Fresnel (con capacidad colectora equivalente a 17,5 soles) y ii) el proceso IHE-ADART que utiliza filtros de arena recubierta con óxido de hierro, IOCS, seguidos de una microfiltración con filtros de polipropileno de 5 y 1 micras dispuestos en serie. El sistema es capaz de remover el arsénico total (particulado y disuelto) hasta concentraciones menores a lo requerido por la guía de la Organización Mundial para la Salud (OMS) y la norma boliviana para agua potable (NB 512) (10 μg/l) en ambas unidades educativas, aun cuando las características hidroquímicas de las aguas tratadas fueron sustancialmente diferentes. Las características del agua de pozo en Cochabamba, favorecen la remoción de arsénico hasta en un 75% por ambos procesos, especialmente el pH, el potencial óxido-reducción y las bajas concentraciones de aniones competidores (cloruros, sulfatos y nitratos) por los sitios de adsorción que están sobre la superficie de los microflóculos de hidróxido férrico o de la capa de óxido férrico que recubre la arena de los filtros IOCS. Por otra parte, las elevadas concentraciones de cloruros, boratos y sulfatos presentes en el agua de pozo que usa la unidad educativa de Quillacas y su alta salinidad no afectan significativamente a la capacidad de adsorción de la arena IOCS, permitiendo elevadas eficiencias de remoción de arsénico (mayores al 90%). En conclusión, el sistema es adecuado, desde el punto de vista técnico para la remoción de arsénico natural presente en aguas subterráneas del valle bajo de Cochabamba y de la zona sur colindante con el lago Poopó en el altiplano boliviano.

Conventional street lighting systems do not allow controlling the light intensity depending on the traffic of pedestrians or vehicles, only operate in two automatic modes (on/off) according to the availability of daylight and consume enormous amounts of electric energy. In this article, we describe the design, development and implementation of a new intelligent street lighting system that is based on LED technology, an energy-efficient embedded wireless control device (hardware) designed from scratch, and photovoltaic solar energy. The embedded device includes specialized firmware and an energy-efficient wireless communication protocol, that allows to form a network of infrared sensors to detect pedestrians and vehicles, so as to control and dim the LED luminaires. We implemented a pilot system in a back road of the campus of Universidad Privada Boliviana, in the city of Cochabamba, Bolivia, where energy consumption measurements confirm energy savings of 72.8% thanks to the developed intelligent control system.

Conventional street lighting systems do not allow controlling the light intensity depending on the traffic of pedestrians or vehicles, only operate in two automatic modes (on/off) according to the availability of daylight and consume enormous amounts of electric energy. In this article, we describe the design, development and implementation of a new intelligent street lighting system that is based on LED technology, an energy-efficient embedded wireless control device (hardware) designed from scratch, and photovoltaic solar energy. The embedded device includes specialized firmware and an energy-efficient wireless communication protocol, that allows to form a network of infrared sensors to detect pedestrians and vehicles, so as to control and dim the LED luminaires. We implemented a pilot system in a back road of the campus of Universidad Privada Boliviana, in the city of Cochabamba, Bolivia, where energy consumption measurements confirm energy savings of 72.8% thanks to the developed intelligent control system.

Identifying minerals in ore concentrates require costly techniques and preparation of samples, thus limiting their instant analysis. We present the development of a low-cost portable LIBS (Laser Induced Breakdown Spectroscopy) system, to identify atomic elements in ore concentrates in-situ and in real-time. The system consists of a YAG:Nd+++ pulsed laser, an optical diffraction spectrometer, and a measurement gun consisting of a laser head and an optical system for collecting light from the sample. We developed customized software for data acquisition, processing and analysis that stores and uses the principal spectral lines of referential atomic elements (Cu, Pb, Ag, Au, Li, Zn). We experimentally obtained spectra of selected samples using our LIBS system, and successfully matched them with the referential spectral lines. Finally, we tested our system with real samples of ore concentrates from a mining company, where the presence of Zn was successfully detected through its characteristic spectrum.

Recently, the use of smartphones has been proposed as a real option for developing measurement instruments in different areas (e.g. bio-sensors, spectroscopy, electro chemical sensor) due to their processing, visualization, connectivity and image capturing capabilities. In this work, we propose the development of a low-cost miniaturized spectrometer that uses the camera of an Android smartphone and processes the images in a self-developed software (spectrometric Android App). It includes a measurement kit with a cuvette holder, an optical fiber with a connecting element, and a high luminous efficiency white LED. The spectrometric Android App allows an initial wavelength calibration and a subsequent calibration for measuring absorbance/transmittance, to obtain spectral curves in real-time. We validated our prototype with a case study in the industrial area, by measuring the concentration of chrome in tanning liquors, and comparing the results with a calibrated conventional spectrophotometer. Thanks to our approach, measurements can be done in-situ and in real-time, thus allowing optimized tanning processes, without requiring expensive measurement equipment.

La microscopía de epifluorescencia es una técnica poderosa con altos niveles de sensibilidad y resolución microscópica que se utiliza en varias áreas, particularmente en el campo biomédico. En este artículo se presenta el diseño y desarrollo de un microscopio de epifluorescencia de bajo costo basado en una fuente laser de excitación, un filtro barrera simplificado, y un sistema embebido (hardware y software) para la visualización y el control digital. El prototipo desarrollado utiliza un filtro barrera por absorción, basado en una solución de Rodamina 6G en alcohol etílico que absorbe de manera efectiva la radiación del láser de excitación y deja pasar la señal fluorescente de la muestra de interés. El poder de aumento del microscopio desarrollado es 100X aproximadamente y permite identificar partículas fluorescentes del orden del 10 m. Los resultados obtenidos con el prototipo desarrollado, muestran su viabilidad para un potencial uso en aplicaciones biomédicas.

El siguiente trabajo presenta la implementación de una fuente de alimentación electrónica, basada en un circuito de ionización de corriente simmer, aplicado a una lámpara flash con Xe, para la excitación de un cristal del tipo YAG:Nd+++. Para el diseño y dimensionamiento de este circuito se utilizaron elementos comerciales de bajo costo. La ventaja de utilizar el circuito de corriente simmer, consiste en la aplicación de alto voltaje (aproximadamente 20 kV) solo una vez, para ionizar la lámpara flash y mantenerla ionizada de manera continua, con una corriente mínima de 40 mA. Este régimen de trabajo de la lámpara flash, permite trabajar al sistema, con frecuencias de disparo hasta los 10 Hz. La aplicación de este circuito en la fuente de energía para los sistemas láseres del tipo YAG:Nd+++ no solo adopta una medida de seguridad importante, al evitar el alto voltaje frecuentemente, sino que también alarga el tiempo de vida de las lámparas utilizadas e incrementa la estabilidad de la salida óptica entre pulsos láser.