Calin Muresan

The paper explores the underutilized potential of geothermal energy in Romania, focusing on both shallow and deep geothermal systems as sustainable alternatives for heating applications. Romania’s unique geological features, particularly the Pannonian Depression, offer significant geothermal resources, yet these remain largely untapped in many regions. This study presents an analysis of the country’s geothermal reservoirs, highlighting their spatial distribution, thermophysical properties, and technical potential. In-depth data on aquifer characteristics, including temperatures, depths, and capacities, supports a comprehensive assessment of the energy output achievable from these natural systems. Current applications of geothermal resources are reviewed, including successful projects in Oradea and Timiș County, which demonstrate the viability of geothermal systems for residential and commercial heating. Furthermore, this study discusses Romania’s regulatory landscape and incentive frameworks aligned with European Union standards, identifying key barriers and opportunities for growth. With a robust foundation of technical and spatial data, this paper underscores the strategic role geothermal energy can play in Romania’s transition to a low-carbon economy, supporting both environmental sustainability and energy resilience. The results demonstrate how geomatics-based resource mapping and spatial analysis support evidence-based planning of geothermal energy systems at regional and national scales.

The eye is a complex structure, with multiple systems involved in focusing and detecting light. Among them, the retina, an integral component of the central nervous system, is considered the most vital and exhibits the highest metabolic activity among all tissues in the human body. It interacts with light, and excessive exposure, especially to blue light, is prone to produce degeneration, mainly through oxidative reactions. This mechanism is involved in age‐related macular degeneration or diabetic retinopathy. Animal research is important, considering the high prevalence of these diseases; yet noninvasive procedures involving this research are lacking so far. Our objective was to apply an animal model of oxidative stress and monitor the metabolic changes using 11.7‐T ¹ H‐magnetic resonance spectroscopy ( ¹ H‐MRS). We exposed adult rats to high intensity blue light, at 440 nm (6000 lx) and investigated retinal metabolic changes up to 48 h post exposure. The acquired spectrum highlighted the presence of several essential retinal metabolites, including lipids (alkyl chain CH ₂ ), lactate, N ‐acetylaspartate (NAA), glutamate (Glu), choline (Cho), taurine (Tau), creatine (Cre), and glucose (Glc). Blue light induced specific changes, relatable to oxidative stress, and ¹ H‐MRS allowed us to follow the dynamic metabolic changes post exposure. This is the first in vivo spectroscopic study of the retinal tissue in which no animals were sacrificed. To validate the in vivo metabolite assignments, localized ex vivo ¹ H‐MRS was performed on eyes from separate animals that had not been exposed to blue light.

This paper presents the design and deployment of a modular IoT-based monitoring infrastructure implemented in Romanian test environments as part of ongoing efforts to support intelligent energy management and environmental data acquisition. The system was developed to provide real-time monitoring of key environmental parameters such as temperature, humidity, proximity and illuminance within designated test rooms, leveraging low-cost, open-source technologies to ensure replicability and scalability. At the core of the platform lies a lightweight data acquisition and communication stack based on the MQTT protocol, enabling efficient transmission of sensor data through a publish-subscribe architecture. Node-RED is employed to orchestrate the data flow locally, process incoming payloads, and display information on a web-accessible dashboard. For extended data visualization and external user access, the system integrates with Grafana, providing advanced charting capabilities and long-term trend analysis. The platform architecture emphasizes modularity, allowing additional sensors or rooms to be added with minimal configuration overhead. It also supports secure remote access via virtual networking, making it suitable for multi-site deployment scenarios. This paper details the system's architecture, implementation, and initial testing results, demonstrating its viability as a foundation for future smart grid pilots and energy-flexibility initiatives.

The aim of this paper is to present a particular approach regarding the functional simulations and mathematical modeling used for bioengineering research and learning programs. The ideas found in this paper were implemented in the laboratory classes for master educational programs on sensors analysis, development and testing techniques. The proposed steps can provide an easy way of learning the specific methods used in this field, the possibility of identifying factors that can generate common errors and solutions that ease data flow in modeling and simulations. Several examples of sensors or biomedical devices were also presented, to emphasize the utility of the mentioned approach. Those case studies can be found in different research studies made by the authors in past research years and are successfully used in teaching materials.

The aim of this paper is to present a solution for basic measurements of the electrical networks parameters. The classical measurement procedure, using analog measurement devices, is replaced with a simple modular data acquisition system, based on a signal conditioning module with Hall Effect transducers. Due to the simplicity of the sensorial acquisition module, it is easy to use for single or multiple phase electrical networks. With the aid of a data acquisition board, the signals were transferred to a virtual instrument, which can compute and display specific quantities that are commonly used in electrical networks monitoring and control processes. The circuits presented in this paper were included in laboratory classes like: Electrical Measurements, Instrumentation and Data Acquisitions, Legal and Applied Metrology. Comparative measurements were performed, comparing the results from three different sources: analog devices, oscilloscope, and data acquisition system. Considering the fact that the presented solution is a didactic one, the user interface has an important role, where the students can simulate various practical situations and compare them with the real measured ones.

The aim of the paper is to present a data acquisition measurement system and a power quality application developed in the LabVIEW programing environment, for a three-phase electrical system. The acquisition system complies of National Instruments acquisition module and Hall Effect transducers. The developed measuring and analysis system will be used for a future stand alone, low cost, three phase spectral analyzer, and as a didactical application for the laboratory classes in the signal processing discipline taught within the Faculty of Electrical Engineering of Cluj-Napoca. The proposed system will be composed of a three-phase consumer circuit in which the voltage and current of each phase will be acquired. To validate the date acquired and computed a three-phase power quality analyzer will be used. The application will provide the most important parameters in power quality: active, reactive and apparent power on each phase and total, the power factor on each phase and also the total power factor, the instantaneous and the rms values for the voltages and currents on each phase, the total harmonic distortion, the spectrum representation for each voltage and current acquired, the fundamental instantaneous and rms values for each voltage and current, the power factor for the fundamental components on each phase, the displacement angle between each voltage and current, and also the direct, invers and 0 components are computed and display.

This paper presents a didactic solution for arterial stenosis analysis that contains mathematical modelling, practical implementation and functional simulation which can provide an easy learning solution for medical, biomedical engineering, or other related branches of students and researchers. For this purpose, several steps are followed, starting with an image captured from an angiography. With the aid of a dedicated software, a mesh will be created, and after a CAD defeaturing process, the blood vessel model will be imported in a simulation program, where real conditions will be analyzed. The next step consists in implementing a flow phantom that will be used for functional simulations. The experimental artery segment will be included in the experimental setup, allowing closer analysis of the pressure by controlling the fluid flow parameters in the probe. With the help of a data acquisition board, signals from the sensors are acquired, processed and displayed using the virtual instrument. Results obtained from mathematical modelling are presented along with user interface captures from two distinct experimental simulations with imposed parameters through the electronic control unit: adjustable fluid flow and pulse sensor synchronized fluid flow.

This paper aims to show the practical implementation of numeric calculus of the Hilbert spaces theory applied in the power analysis and compensation. While we wrote about equations and calculation methods, this paper is expressing the actual work done in LabVIEW programing environment. Numerical analysis programs have numerical computing tools for these sizes. Thus, the analysis of polyphase circuits can be done easily. Further analysis examples will be carried out using Hilbert spaces. LabVIEWapplications have been developed to implement the algorithms described in the theoretical part. The application is adaptable for any number voltage and current systems. The examples will be dedicated to penta-phase systems.

This paper presents aspects regarding the response of a mechanical shock transducer that contains a Hall effect sensor as detecting element. An algorithm was developed in order to predict and analyze the behavior of the transducer's components interaction. This calculus model is focused on the movement of the elastic element of the shock transducer that is driven by external forces and contains a permanent magnet that produces the magnetic field needed to influence the Hall sensor. Two different types of mechanical excitation sources, rectangular and triangular, were considered. The excitation forces were applied to the transducer's support, the aim of the paper being to confer a prediction chain from mechanical movement to magnetic field fluctuation and finally to Hall voltage variation at the output of the transducer. Some constructive aspects related to the presented transducer were also presented.

The current paper presents some basic tools developed in the LabVIEW environment. It is focused on the mathematical formulation and the implementation of the equation. It will show a simple solution developed by the authors for some of the most necessary parameters used in the Power analysis literature, like: determining the fundamental frequency of a signal, linear filtration using DFT, computation of the Total Harmonic Distortion (THD), determining the initial phase of an acquired signal or a method for phase shifting.