A conceptual model for integrating sustainable supply chain, electric vehicles, and renewable energy sources

The effects of climate change can be seen immediately in ecosystems. Recent events have resulted in a commitment to the Paris Agreement for the reduction of carbon emissions by a significant amount by the year 2030. Rapid urbanisation is taking place to provide room for an increasing number of people’s residences. Increasing the size of a city and the number of people living there creates a daily need for consumable resources. In the areas of transportation, supply chains, and the utilisation of renewable energy sources, deliver on pledges that promote the accomplishment of the Sustainable Development Goals established by the United Nations. As a result, the supply chain needs to be handled effectively to meet the requirements of growing cities. Management of the supply chain should be in harmony with the environment; nevertheless, the question of how to manage a sustainable supply chain without having an impact on the environment is still mostly understood. The purpose of this study is to present a conceptual model that may be used to maintain a sustainable supply chain with electric vehicles in such a way that caters to both environmental concerns and human requirements. As part of the continual process of achieving sustainability, interrelationships between the various aspects that are being investigated, comprehended, and applied are provided by the model that was developed. It is self-evident that governmental and international organisations that are concerned with supply-demand side information will benefit from such a model, and these organisations will locate viable solutions in accordance with the model’s recommendations. Beneficiaries consist of individuals who are active in the supply chain and are concerned with supply-demand side information. These individuals also need to understand how to effectively manage this information

Lean and its impact on sustainability performance in service companies: results from a pilot study

Purpose: The purpose of this empirical research is to understand the application of Lean practices (technical and social) and tools in the service sector, whose implementation is less studied, despite its economic relevance. The study aims to extend previous studies that focused on the relationship between Lean and operational and financial performance, and analyzing the impact on sustainability, encompassing economic, social and environmental perspectives. Design/methodology/approach: A pilot survey was conducted with Lean experts in European service companies. The authors have utilized various professional contacts on LinkedIn and a satisfactory response rate was obtained for analysis. Findings: The results of the study showed that there are several motivating factors for the implementation of Lean, the highlights being improving customer satisfaction, efficiency, delivery and cost reduction. The most frequently used Lean tools are related to the identification of improvement opportunities and causes of problems. The pilot survey also made it possible to identify the greater use of technical practices than social practices. The sustainability performance analysis showed that the better performance of service companies is in the economic dimension. Originality/value: The authors have identified no empirical studies linking Lean and sustainable performance in the service sector. This study bridges this cognitive gap through a pilot study and therefore makes an original contribution to the current literature. © 2022, Emerald Publishing Limited

Ventricular Tachycardia in Repaired Double Chambered Right Ventricle - Identification of the Substrate and Successful Ablation

A 35 year old female presented with recurrent ventricular tachycardia 5 years after she had undergone surgical repair of double chambered right ventricle. Electroanatomical mapping showed a localised scar in the apex with double potentials and good pace map. Ablation here resulted in non-inducibility of ventricular tachycardia. We hypothesise that the scarring in the apex is the result of sustained pressure overload and becomes arrhythmogenic similar to the apical scar in patients with mid-ventricular hypertrophic cardiomyopathy

NFT Certificates and Proof of Delivery for Fine Jewelry and Gemstones

Fine jewelry is a unique class of ornaments composed of precious metals and gemstones. Premium-grade metals such as gold, platinum, and sliver, and gemstones such as pearls, diamonds, rubies, and emeralds are used use to make fine jewelry. Paper-based certificates are typically issued by retailers and producers for fine jewelry and gemstones as a proof of origin, sale, ownership, history, and quality. However, paper certificates are subject to counterfeiting, loss, or theft. In this paper, we show how non-fungible tokens (NFTs) and Ethereum blockchain can be used for digital certification, proof of ownership, sale history, and quality, as well as proof of delivery for fine jewelry and gemstones.We present the proposed system design and architecture with sequence diagrams covering key interactions for jewelry production, purchase, and sale, along with algorithms related to NFT minting, auctioning, ownership management, and physical delivery. We demonstrate that our proposed NFT and blockchain-based solution can provide superior alternative in terms of verifiability, traceability, immutability, and security when compared with paper-based certification and traditional auctioning, delivery and ownership management. We make our developed smart contracts and testing scripts publicly available on GitHub

Blockchain-Based Verifiable Tracking of Resellable Returned Drugs

An enormous amount of drug supply is regularly wasted due to several reasons related to incorrect prescription, purchase of unnecessary quantities, drug intolerance, allergy, or interactions. On the other hand, these medicines may be needed by patients who cannot afford to purchase them. To address this challenge, we propose a fully decentralized solution that governs the return and redistribution of unused drugs that are fit for usage. Our approach exploits the decentralized blockchain technology, smart contracts, and decentralized storage systems such as the Interplanetary File Systems (IPFS).We develop a system that provides the ability for customers as well as pharmacies to return re-usable, resellable drugs for donation or resale at a lower price. The proposed scheme tracks the production of drugs from manufacturers to traders that subsequently sell them to customers. Unused drugs can be returned after approval by specialized entities and then redistributed. In particular, we present the decentralized system architecture and implement a prototype on a test Ethereum blockchain platform to present the suggested workflow. Further, we provide system evaluation focused on assessing system functionality, performance, execution cost, and security of smart contracts and their robustness. We have also made our smart contracts code publicly available on Github

Trustworthy Blockchain Gateways for Resource-Constrained Clients and IoT Devices

Constrained blockchain clients are unable to process and store the entire blockchain ledger and mine blocks on the blockchain. Such nodes rely on the view of blockchain provided by full nodes termed as gateways. However, gateway nodes can provide a distorted view of the blockchain, making lightweight clients vulnerable to eclipse attack. When under such an attack, a client cannot differentiate between a forked view of the blockchain and the legitimate blockchain ledger leading to fatal consequences and huge losses incurred. To mitigate such threats, we propose a data attestation solution which employs full nodes as validators to attest the responses reported by gateways of lightweight nodes. Leveraging smart contracts, our approach gives lightweight clients confidence in the data reported as they are unable to validate it from the blockchain network itself. The system governs the attestation process that comprises of submitting attestation requests, approving them, recording the response of validators, and manage payments. Clients can, thereafter, provide their feedback about the validator/gateway performance in the form of a reputation score. We present the proposed system architecture and describe its implementation on the Ethereum blockchain network. We evaluated the proposed solution with respect to functionality testing, cost of execution, and security analysis of smart contracts developed.We have also made our smart contracts code publicly available on Github

Interference Mitigation Based on Radio Aware Channel Assignment for Wireless Mesh Networks

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. An intricate network deployment for high demand users leads to simultaneous transmission in wireless mesh networks. Multiple radios are adapted to individual nodes for improving network performance and Quality of Service (QoS). However, whenever multiple radios are assigned to the same channel, co-located radio interference occurs, which poses a major drawback. This paper proposes a Radio aware Channel Assignment (Ra-CA) mechanism based on a direct graphical model for mitigation of interference in multi-radio multi-channel networks. Initially, the co-located radio interference is identified by classifying non-interfering links for simultaneous transmission in the network. Proposed channel assignment mechanism helps in allocating the minimal number of channels to the network that mitigate co-located radio interference. Performance analysis of the proposed Ra-CA strategy is carried out compared with other existing techniques, like Breadth First Search-Channel Assignment (BFS-CA) and Maximal Independent Set Channel Assignment (MaIS-CA), in multi-radio networks. Simulation results demonstrate that the proposed channel assignment scheme is more efficient compared to the existing ones, in terms of QoS parameters like, packet drop rate, packet delivery ratio, transmission delay and throughput

Blockchain-Based Traceability and Management for Additive Manufacturing

Additive Manufacturing (AM) is a major advancement in the digitization of manufacturing and production operations. Additive manufacturing uses three dimensional digital design, software and hardware equipment to precisely deposit layered materials for on-demand product manufacturing. The distinct advantages in enabling additive manufacturing includes cost efficiency, reduced time-to-market, flexibility and precise customization. However, several challenges such as trusted traceability, certification for quality compliance, and protecting intellectual property need to be addressed. Blockchain-based distributed ledgers provide tremendous advantages for product traceability and ensure trust among participating stakeholders. In this paper, we propose a blockchain-based solution for product traceability produced using additive manufacturing, guaranteeing secure and trusted traceability, accessibility, and immutability of transactions, and data provenance among supply chain stakeholders. Our proposed solution utilizes Ethereum smart contracts to govern and trace transactions initiated by participants involved in the manufacturing process. Decentralized storage of Inter-Planetary File Systems is used to store and share design files, IoT device records, and additional product specifications. We provide the system architecture, implementation, and detailed algorithms that demonstrate the working principles of our proposed solution for secure AM. Furthermore, we present detailed security and cost analysis of the solution highlighting its efficiency with respect to key security and performance requirements

appXchain: Application-Level Interoperability for Blockchain Networks

Blockchain technology has the potential to revolutionize industries by offering decentralized, transparent, data provenance, auditable, reliable, and trustworthy features. However, cross-chain interoperability is one of the crucial challenges preventing widespread adoption of blockchain applications. Cross-chain interoperability represents the ability for one blockchain network to interact and share data with another blockchain network. Contemporary cross-chain interoperability solutions are centralized and require re-engineering of the core blockchain stack to enable inter-communication and data sharing among heterogeneous blockchain networks. In this paper, we propose an application-based cross-chain interoperability solution named appXchain which allows blockchain networks of any architecture type and industrial focus to inter-communicate, share data, and make requests. Our solution utilizes the decentralized applications as a distributed translation layer that is capable of communicating and understanding multiple blockchain networks, thereby delegating requests and parameters among them. The architecture uses incentivized verifier nodes that maintain the integrity of shared data facilitating them to be readable by the entities of their network. We define and describe the roles and requirements of major entities of inter-operating blockchain networks in the context of healthcare. We present a detailed explanation of the sequence of interactions needed to share an Electronic Medical Record (EMR) document from one blockchain network to another along with the required algorithms. We implement the appXchain solution with Ethereum-based smart contracts for two hospitals and also present its cost and security analysis. We have made our smart contracts code and testing scripts publicly available