National Institute of Research and Development for Optoelectronics

<strong class="journal-contentHeaderColor">Abstract.</strong> A decade-long (2015&ndash;2024) analysis of aerosol properties was conducted at RADO-Bucharest station in Romania a key atmospheric observational site at the Eastern border of the Aerosol, Clouds and Trace gases Research Infra-structure (ACTRIS). This study aims to characterize the optical and microphysical properties of aerosols, classify predominant aerosol types, and investigate their seasonal variability and transport pathways based on long-term multiwavelength Raman lidar and sun/sky/lunar photometer measurements. Results indicate a dominance of fine-mode aerosols, with an average Aerosol Optical Depth (AOD) of ~0.2 and Ӓngstr&ouml;m Exponent (AE) values between 1.5&ndash;2.0, highlighting pollution-driven aerosol regimes. Seasonal variations were observed, with continental aerosols prevailing in winter, dust transport peaking in spring (altitudes of 2&ndash;8 km), and biomass-burning aerosols increasing during summer. Marine aerosols were occasionally detected at ~2 km altitude, often mixed with dust. Analysis of 408 aerosol layers using the NATALI (Neural network Aerosol Typing Algorithm based on LIdar data) identified complex aerosol mixtures, with 63 high-resolution cases revealing a predominance of &ldquo;dust polluted&rdquo; and &ldquo;continental smoke&rdquo; types. Lidar-derived extinction Ӓngstr&ouml;m coefficients (median ~0.9 in the low troposphere) and lidar ratios (~48 sr in the low troposphere, ~49 sr in the high troposphere) suggest varying optical properties linked to aerosol composition and absorption characteristics. FLEXPART (FLEXible PARTicle dispersion model) retro-plume simulations provided insights into aerosol source regions and transport patterns showing contributions from local emissions, long-range transported desert dust, and biomass burning events from Europe and North America. These findings emphasize the persistent influence of regional pollution and transported aerosols on air quality and climate. The integration of ground-based remote sensing and advanced retrieval algorithms like NATALI provides a robust framework for aerosol characterization, enhancing climate models and air quality assessments.

Nanostructured thin films are emerging into a diversified class of materials with unique optical, chemical, and physical capabilities as a result of their nanoscale characteristics. This paper provides a complete review of the manufacturing, characterization, and applications of nanostructured thin films in a range of industries such as photonics, electronics, energy storage, and medicine. The relationship between nanostructure morphology and material performance is discussed, as well as the most recent advances in fabrication technologies such as physical vapor deposition, chemical vapor deposition, and solution-based methods.

The paper presents the design and development of a novel lidar receiver telescope optimized for near-range atmospheric profiling within the ACTRIS framework. ACTRIS (Aerosol, Clouds and Trace Gases Research Infrastructure, www.actris.eu) is the European research infrastructure for the observation of short-lived atmospheric constituents, supporting high-quality data for climate and air quality research. The telescope is engineered to significantly reduce the geometric overlap altitude, enabling accurate aerosol and cloud measurements starting as low as 140 meters above ground level. This improvement is essential to access information about the dynamics and structure of the first hundred meters of the atmosphere, particularly the lower part of the planetary boundary layer (PBL), which plays a key role in pollutant dispersion, cloud formation, and aerosol interactions. Up to now, most instruments operating within ACTRIS do not have a near-range telescope implemented, limiting their ability to monitor the lowermost atmospheric layers with sufficient spatial resolution. The system features a compact 76.2 mm diameter optical assembly with a total focal length of 392.2 mm and a narrow field of view of 2.04 mrad. A precision aperture iris (0.8 mm) and an image reduction system using plano-convex UV Fused Silica lenses ensure high spatial resolution and minimal optical aberrations. The telescope configuration, tailored for a 100 mm axis separation and a 0.5 mrad tilt, supports improved overlap with the laser beam. The detection system is based on a Hamamatsu photomultiplier tube (PMT) optimized for high-sensitivity measurements at 532.72 nm, enabling robust signal retrieval in the near field. Results demonstrate reliable performance up to 14 km during daytime operation and up to 20 km during nighttime, confirming the telescope's suitability for continuous atmospheric monitoring. This development represents a key step toward enhancing near-ground sensitivity and operational capabilities of multi-wavelength high-power lidar instruments in the context of ACTRIS.

Top Lit Up Draft (TLUD) gasification technology has proven to be an efficient and sustainable solution for biomass-to-heat conversion, with wide adoption in agriculture and industry. However, its integration into modern digital ecosystems remains limited. This paper proposes enhancing the inherent value of TLUD systems by equipping them with IoT capabilities-transforming a well-established but traditionally isolated device into an intelligent, connected, and responsive system. The implementation of an architecture based on embedded hardware platforms and client-server hardware/software technologies enables real-time monitoring and control of the gasifier, both locally and remotely. The custom-developed software enables cloud integration for data analytics, predictive maintenance, and service-oriented business models. The result is a functional prototype that meets current demands for connectivity and automation, contributing to the wider adoption of TLUD systems within the Internet of Things framework.

Composites were obtained by using a commercial bicomponent epoxy resin (containing Al2O3 and SiO2) and cubic BN (cBN) (0–50 wt.%). Two preparation methods were used: (a) the cBN powder was first mixed with the resin base and further with the hardener, and (b) the cBN powder was first mixed with hardener and afterwards with the resin base. Both methods show a similar enhancement trend in the thermal conductivity from 0.77 W/mK in the resin without additive to 1 and 1.5 W/mK in the ones filled with 30 and 50 wt.% cBN, respectively. A reasonable decrease in bending strength from 74 for 0 wt.% cBN to 70 or 64 MPa for 30 wt.% cBN added by method (a) or (b), respectively, occurs. The bending strain at breakage decreased from 5.58% to 2.65 or 3.78%. High sensitivity vs. processing was also found for electrical properties measured for frequencies of 1–107 Hz. An increasing amount of cBN decreased the room temperature conductivity, dielectric constant, and dielectric loss tangent and modified the shape of the curves vs. frequency. However, in samples with 30 wt.% or more of cBN, a partial recovery to a high insulating state was observed.

Abstract. This study examines the microbial and geochemical environment surrounding mirabilite (sodium sulfate decahydrate) deposits in Izvorul Tăușoarelor Cave, located in the Romanian Carpathians. Using a metabarcoding approach, we analysed mirabilite, sediments, dipluran insects, drip water, and moonmilk deposits to investigate the microbial communities and elemental profiles linked to mirabilite formation. Elemental analysis revealed a geochemical signature in mirabilite samples that was dominated by sodium, sulfur, and calcium. Microbial profiling revealed a unique pattern: sulfur-reducing bacteria, such as Desulfobacterota, were absent in mirabilite samples, whereas Pseudomonas dominated, suggesting an alternative sulfur cycling pathway that potentially involves sulfide biooxidation. The presence of ammonia-oxidising archaea (Ca. Nitrocosmicus) exclusively in the mirabilite area, and of bacteria (Nitrococcus), indicates a possible influence from a small bat colony, which contributes minimal ammonia that may support the microbial equilibrium required for mirabilite growth. Actinomycetota, abundant in mirabilite, may facilitate mineral crystallisation through mycelium-like structures. We propose the term “microbiocosm” to describe the interconnected network of biotic and abiotic elements surrounding the mirabilite environment, proposing a novel framework for investigating microbial contributions to this mineral formation.

Background: Cesarean deliveries have increased in recent years worldwide. This increase translates into an escalation of obstetrical complications that could lead to permanent injuries. Comprehensive knowledge of the risk factors for uterine scar defects and their probability factor could guide gynecologists towards decreasing the percentage of scar defects and reducing the morbidity produced by a scarred uterus. Methods: A review of the literature published in the last 10 years produced a number of 80,085 articles, from which we screened 147 articles and selected 11 recently published papers, attempting to rank the most frequently described risk factors in terms of probability. A total number of 11,349 patients who underwent CS were included from the 11 studies. Results: Cesarean scar defects developed in 19.42% of cases; our results showed that the highest probability was given by single-layer suture, with gestational diabetes being the main patient-related risk factor for scar defects. A definitive ranking of the risks is difficult to assess, because different studies focus on certain risks and most of the relevant data are missing or are omitted. Conclusions: In this study, we investigate the most common risk factors that give rise to the development of cesarian scar defects, conducting a ranking of these risks from the most probable to the least important, in order to facilitate informed decision making for providers.

ABSTRACT The Roman fort near Ungra, southeastern Transylvania, offers new insights into Roman military presence and strategies in Dacia. This study employs a multidisciplinary approach, including satellite imagery, drone surveys, geophysical investigations, archaeological excavations, and digital reconstruction to analyze the fort’s location, structure, and historical significance. The fort features a double ditch and rampart system, with evidence of both timber and stone construction phases. Key finds, including the Principia, military artifacts such as ballista and sling projectiles, and metallurgical slag, suggest active military use for both defense and offense. Its strategic location allowed control over key communication routes, while its proximity to the large auxiliary fort at Hoghiz implies an interconnected network of defenses. The digital reconstruction of the fort enhances our understanding of Roman military architecture. This research significantly contributes to the archaeological record of Roman Dacia and the study of frontier dynamics in Transylvania.

This study investigates the impact of a thermal power plant site on air quality in Bucharest, Romania. It emphasizes the importance of accurate air pollutant inmission measurements in urban areas by utilizing mobile measurements of low-cost sensors, Copernicus’ Copernicus Atmosphere Monitoring Service (CAMS) and Copernicus Land Monitoring Service (CLMS), and satellite retrieval to better understand climate change drivers and their potential impact on near- surface concentrations and column densities of NO2, CO, and PM (particulate matter). It focuses the attention on the need of considering the placement of power plants in relation to metropolitan areas while making this assessment. The research highlights the limits of typical mesoscale air quality models in effectively capturing pollution dispersion and distribution using LUR (Land Use Regressions) retrievals. The authors investigate a variety of ways to better understand air pollution in metropolitan areas, including satellite observations, mobile measurements, and land use regression models. The study focuses largely on Bucharest, the capital of Romania, which has air pollution issues caused by vehicle traffic, industrial activity, heating systems, and power plants. The results indicate how the placement of a power plant may affects air quality in the nearby residential areas.