Vladimir Ciobanu

This paper presents the development of a hardware - software platform designed for controlling and monitoring devices from the Keithley 2400 SourceMeter series. The system uses a laboratory-designed hardware adapter based on the ATmega328P microcontroller for serial - parallel conversion and an ESP32-C3 module for managing network communication and transmitting commands according to the GPIB (IEEE-488) protocol. The software platform includes a web interface accessible both locally and remotely through Wi-Fi connectivity and a centralized server. The system implements two access levels-administrator and standard user-allowing configuration of internal parameters, sending GPIB commands, executing tests, and viewing system logs. For secure access, the application employs unique authentication tokens, packet integrity verification, and automatic restriction of unauthorized IP addresses. The application enables measurement reading in multimeter mode, automatic saving to CSV files, real-time graph generation, and communication error diagnostics. Additionally, the system can operate as a programmable source, supporting both potentiostatic and galvanostatic modes, making it suitable for electrochemical applications, automated testing, and remotely controlled experiments. The results confirm the stability of the GPIB communication, the expandability of the platform, and its integration potential within modern laboratory infrastructures.

This study presents a comprehensive investigation of the structural and optical properties of SnS and SnS₂ compounds, integrating techniques such as powder X-ray diffraction, electron microscopy, and optical spectroscopy. The Xray diffraction analysis confirms the identification of phases and lattice parameters, revealing the effects of synthesis conditions on crystalline quality and crystallite size. Electron microscopy illustrates the layered growth of the materials, with dimensions around 5 nm, bonded through Van der Waals forces. Optical characterization highlights absorption edges corresponding to band-gap energies of approximately 1.25 eV for SnS and about 2.0 eV for SnS₂, with absorption coefficients reaching up to 10⁵ cm⁻¹ in nanostructured forms. Applications in photovoltaics, photocatalysis, and photodetection are discussed, emphasizing the materials' capability for energy harvesting.

In March 2017, a small hoard of tools consisting of six bronze sickles was discovered near the village of Călmățui (Hâncești district). All the items are hooked sickles, well known in the Carpathian-Dniester region during the Late Bronze Age – BrD-HaA1 (13th century – first half of the 12th century BC). In particular, several similar finds are known on the Middle and Lower Prut. Typological analysis showed that all the items belong to the Ghermănești type, the Ruginoasa variant, which allows us to narrow the chronological interval to the second half of the 13th century BC. Elementary chemical analysis of the items was carried out using an electron microscope (SEM) equipped with an EDX detector and the X-ray diffraction method (XRF). Various research methods obtained in independent laboratories in Chișinău demonstrated their effectiveness, while XRF allowed for greater measurement accuracy.

One of the biggest issues of wide bandgap semiconductor use in photocatalytic wastewater treatment is the reusability of the material and avoiding the contamination of water with the material itself. In this paper, we report on a novel TiO₂ aeromaterial (aero-TiO₂) consisting of hollow microtetrapods with Zn₂Ti₃O₈ inclusions. Atomic layer deposition has been used to obtain particles of unique shape allowing them to interlock thereby protecting the photocatalyst from erosion and damage when incorporated in active filters. The performance of the aero-TiO₂ material was investigated regarding photocatalytic degradation of tetracycline under UV and visible light irradiation. Upon irradiation with a 3.4 mW/cm² UV source, the tetracycline concentration decreases by about 90% during 150 min, while upon irradiation with a Solar Simulator (87.5 mW/cm²) the concentration of antibiotic decreases by about 75% during 180 min. The experiments conducted under liquid flow conditions over a photocatalyst fixed in a testing cell have demonstrated the proper reusability of the material.