Convergence of Distributed Ledger Technologies with Digital Twins, IoT, and AI for fresh food logistics: Challenges and opportunities

The growing demand for fresher and better quality food products has led various researchers to propose solutions in this field. Besides the increase in food production, the efficiency of food logistics must be improved to reduce waste. An efficient food supply chain also reduces the final cost of products, increases producers’ incomes, mitigates the environmental impacts, and allows transportation of fresher, healthier foods. Collection and analysis of information on product tracking and stakeholder demands can improve supply chain efficiency, providing important insights to managers. Technological solutions, such as the Internet of Things (IoT), Artificial Intelligence (AI), Digital Twin (DT), and Distributed Ledger Technology (DLT), have been proposed for monitoring and tracking products and analyzing data collected while supporting decision-making. However, there are still few studies about the integration of these technologies, especially DTs, intelligent models, and DLTs. Thus, this work presents a review of the application of these technologies for food logistics, identifying the main requirements and summarizing how they can be applied in each logistics stage. Related surveys are discussed to find gaps in the literature and six research questions are defined and answered, aiming to argue about how the chosen technologies can be applied and combined to attempt the identified requirements. Lastly, this work discusses research opportunities in the fresh food supply chain, presenting some open challenges for adoption while integrating these technologies

Coldnet: Vaccine Logistics Tracking by Integrating the Internet of Things and Smart Contracts: An Immutable and Reliable Approach

Reliable vaccine tracking and monitoring during transport and storage are essential to ensure dose effectiveness while minimizing waste. However, current solutions face challenges related to reliability, immutability, security, transparency, flexibility, extensibility, patient support, trust, and cost. Centralized systems are vulnerable to fraud, tampering, and manipulation, often relying on manual service contracts and lack of attested IoT devices to ensure data authenticity. Moreover, most existing platforms do not provide tamper-proof, near real-time monitoring, resulting in operational vulnerabilities and increased costs. This article presents Coldnet, a novel architecture for vaccine tracking and tracing that addresses these issues by: (i) integrating IoT device attestation with the registration of immutable data and flexible monitoring attributes; (ii) using Blockchain-based smart contracts to automatically manage tracking and monitoring clauses, improving security and enabling dynamic rule management; (iii) offering intuitive interfaces to support patient access to delivery information; and (iv) deploying an affordable, user-friendly IoT prototype to monitor and report vaccine status. A case study demonstrates Coldnet's feasibility, with an average delay of 20 seconds for recording and checking conditions — suitable for real operations. A simulation evaluating scalability and the impact of IoT attestation shows transaction costs of US$1.51 for ten vaccine batches with five monitored properties each, a cost deemed acceptable for the added features. Execution delays remained stable (0.85–0.92 seconds), with negligible impact from attestation. Coldnet contributes to reliable vaccine logistics, improving public health efforts by strengthening trust, transparency, and data integrity in vaccination campaigns

G305.8 - 0.2: A Young Object with a Dust and Gas Envelope

The H2O maser source in G305.8 - 0.2 was first detected by Haynes et al. (1984). Inspection of the Southern Hemisphere radio surveys did not show any strong compact HII region or water maser placed nearby this source. The IRAS point source catalog (2.0) shows a strong source in the direction of the maser. We analysed the temporal variation and line profile of the H2O maser emission and discussed the nature of its associated IRAS source. These source characteristics seem compatible with the hypothesis that the maser is associated with a protostellar disk around an early-type star of spectral type 07 to 09 surrounded by a spherical shell of gas and dust.</jats:p