Valentina Nikolova

The quest for security has accompanied humanity throughout its evolutionary development, from the Stone Age to the present day. Security is identified with a state of protection, with the physical and moral survival of the individual, with their freedom and rights, and with their spiritual and social development. This defines the multifaceted nature of the concept of “security,” which centers on the individual and society. Human security has many dimensions, of which food security is vital. Given its significance, the management of food security is a matter of state policy and national security. This article traces the origins, evolution, and current state of food security on a global, European, and national scale.

This study evaluates long-term (2014–2023) and seasonal water quality in the Jerma River, a transboundary watershed between Serbia and Bulgaria, using annual mean physicochemical and microbiological parameters at two monitoring sites as well as Water Pollution Index (WPI) classifications. Seasonal datasets (spring, summer, autumn and winter) were applied to assess intra-annual variability. The water quality reflects the influence of geomorphology, hydrological seasonality, and anthropogenic pressures. The river reflects the influence of geomorphology, hydrological seasonality, and anthropogenic pressures typical of mountain catchments. Upstream conditions were favorable, characterized by stable oxygen regimes, low suspended solids, and low nutrient levels, with occasional phosphorus enrichment. Downstream sections showed stronger deviations, including elevated nutrients, departures from reference conditions, and variability in microbiological indicators. Seasonal analyses indicated stable oxygen conditions at both sites, while nutrient and microbial parameters varied during specific periods. Dissolved metals remained within Class I thresholds throughout the study. WPI values confirmed spatial and seasonal differences. Upstream water quality mainly corresponded to Class II, with occasional shifts toward Class III, whereas downstream values fluctuated between Classes II and IV, with short-term deterioration during seasons. Higher variability occurred in spring and summer, while winter conditions were more stable. Overall, the results indicate better upstream status and increased nutrient and microbial pressures downstream, highlighting the need for continued monitoring and management.

Torrential flows are hazardous hydro-geomorphological phenomena characterized by sudden water discharge and intense sediment transport. They occur in mountainous areas where hydrometeorological monitoring is often limited or absent. The lack of such data hinders the identification of flow types and sediment transport conditions, reducing the effectiveness of mitigation measures. To address this issue, the current study focuses on geomorphic characteristics of torrential watersheds and identifies indirect indicators of torrential activity. The sedimentological and geomorphic signatures of torrential flows in the lower Damdere River catchment (Eastern Rhodopes Mountains, southern Bulgaria) were characterized. To capture inter-annual variability in torrential activity and differences between the Damdere and its tributary the Duandere, we sampled riverbed deposits. We also sampled areas upstream and downstream of the check dam to assess its influence. Samples were analyzed for grain size distribution, petrography, and mineralogy (X-ray diffraction). Results show contrasting controls on sediment supply and transport: the Duandere delivers relatively coarse material, whereas the Damdere attains higher transport capacity during torrential events. The check dam is largely infilled and exerts only local effects by trapping finer sediments upstream. Downstream, the channel retains its torrential character. Inter-annual comparison upstream of the structure shows sediment fining linked to lower flows. Petrographic and XRD data point to mechanically driven erosion and rapid sediment transfer. The results underline the importance of geological–geomorphological indicators in the lack of long-term monitoring in similar mountain catchments and can support flood risk management.

This study investigates temporal and spatial variation in torrential flood hazards and sediment dynamics in two ungauged watersheds in southeastern Serbia from 1991 to 2023. By integrating classical hydrological models with modern geospatial and photogrammetric techniques, watershed responses to environmental and anthropogenic changes are quantified. Torrential flood potential was estimated and peak discharges were calculated using both the rational and SCS-Unit hydrograph methods, while sediment transport was assessed through Gavrilović’s erosion potential model and a modified Poljakov model. A key innovation is the use of UAV-based and close-range photogrammetry for 3D grain-size analysis, marking the first such application in Serbia. The mean torrential flood potential decreased by 4.4% in the Petrova Watershed and 4.2% in the Rasnička Watershed. Specific peak discharges for a 100-year return period declined from 1.62 to 1.07 m³·s⁻¹·km⁻² in Petrova and from 1.60 to 1.34 m³·s⁻¹·km⁻² in Rasnička. Sediment transport during a 1% probability flood was reduced from 4.97 to 2.53 m³·s⁻¹ in Petrova and from 13.87 to 9.48 m³·s⁻¹ in Rasnička. Grain-size analyses revealed immobile coarse bedload in the Petrova and active sediment transport in the Rasnička River, where D50 and D90 decreased between 2023 and 2024. The findings highlight the effectiveness of a synergistic methodological approach for analyzing complex watershed processes in data-scarce regions. The study provides a replicable model for flood hazard assessment and erosion control planning in similar mountainous environments undergoing socio-environmental transitions.

The article examines the application of collaborative robots (cobots) as a modern engineering tool for the transformation of the food industry following the principles of Industry 5.0. A conceptual engineering model has been developed that integrates collaborative robots with IoT systems, digital twins, and predictive analytics to increase the flexibility, safety, and sustainability of production processes. The proposed model is validated through a practical case study focused on a yogurt packaging line in the dairy sector, where cobot systems demonstrate a significant improvement in operational efficiency and process safety. A step-by-step strategic roadmap is presented to guide industrial enterprises through the various stages of implementation, from the initial assessment to the full-scale integration of solutions. Additionally, a comparative analysis has been performed between traditional automated systems and the integrated approach with collaborative robots, which highlights the technological, economic, and human-oriented advantages of the latter. The results of the study confirm that collaborative robotics offers an effective and applicable path for transforming the food and beverage industry towards a sustainable, adaptive, and human-centered manufacturing ecosystem characteristic of Industry 5.0.

In the context of increasing demands for sustainability and individualization in the food industry, additive manufacturing (AM) represents a promising technology with the potential to transform manufacturing processes. This study proposes an integrated engineering–environmental analysis of the applicability of additive manufacturing in the food sector through a combined methodological framework, including techno-economic assessment (TEA) and life cycle assessment (LCA). This article provides a structured methodology and practical engineering models for assessing additive manufacturing. These can support strategic decision-making by industrial manufacturers and research communities aiming for sustainable and flexible manufacturing systems.

In the context of growing threats in the digital space, cyber security has established itself as a critical component for protecting information systems. With the increasing reliance on digital technology and the Internet, the risks of cyber-attacks and unauthorized access to sensitive data have greatly increased. This highlights the need to develop advanced security mechanisms that ensure the overall safety of systems. Traditional security methods often fail to cope with the complexity of modern threats. Organizations are therefore exploring new technologies, such as blockchain and artificial intelligence, that offer higher levels of security. Blockchain provides innovative solutions that decentralize identity management and reduce dependence on centralized servers. This paper aims to present a methodology combining two blockchain authentication methods – MetaMask Authentication and Smart Contract-Based Authentication, for implementation and analysis, ensuring overcoming challenges in real applications.

Debris flows and debris floods are a natural hazard that commonly occurs in mountainous regions. They can cause significant damage to infrastructure and pose serious threats to safety. Historical occurrences of debris flows can be identified through the deposits they leave behind. Studying these deposits offers valuable insights into these destructive events and supports improving prevention strategies’ development. In this regard, the study article is focused on the grain size analysis of the deposits of temporary flow by sieve/aerometric method. The obtained results confirm the torrential character of the river.

This study examines the riverbed in the lower course of the Damdere River in the Eastern Rhodope Mountains (southern Bulgaria), a region prone to torrential flow events. Two field campaigns were carried out – in October 2023 and October 2024, employing terrestrial photogrammetry to generate high-resolution 3D point clouds for the computation of geometric features of the riverbed. Using CloudCompare open source software, roughness values were calculated from the photogrammetric data and compared with manually measured sediment “b” axis values. Results show that maximum roughness values were higher in 2024, but more significant spatial variability of the roughness across the test site is observed at the 3D point cloud of 2023, likely reflecting sediment transport due to torrential flows. These findings suggest that in the absence of rain gauges, sediment size, and roughness data serve as viable indicators of torrential activity, with local rainfall patterns supporting erosion and sediment displacement.