The year 2020 has witnessed unprecedented levels of demand for COVID-19 medical equipment and supplies. However, most of today's systems, methods, and technologies leveraged for handling the forward ...supply chain of COVID-19 medical equipment and the waste that results from them after usage are inefficient. They fall short in providing traceability, reliability, operational transparency, security, and trust features. Also, they are centralized that can cause a single point of failure problem. In this paper, we propose a decentralized blockchain-based solution to automate forward supply chain processes for the COVID-19 medical equipment and enable information exchange among all the stakeholders involved in their waste management in a manner that is fully secure, transparent, traceable, and trustworthy. We integrate the Ethereum blockchain with decentralized storage of interplanetary file systems (IPFS) to securely fetch, store, and share the data related to the forward supply chain of COVID-19 medical equipment and their waste management. We develop algorithms to define interaction rules regarding COVID-19 waste handling and penalties to be imposed on the stakeholders in case of violations. We present system design along with its full implementation details. We evaluate the performance of the proposed solution using cost analysis to show its affordability. We present the security analysis to verify the reliability of the smart contracts, and discuss our solution from the generalization and applicability point of view. Furthermore, we outline the limitations of our solution in form of open challenges that can act as future research directions. We make our smart contracts code publicly available on GitHub.
Cloud computing services have gained tremendous popularity and widespread adoption due to their flexible and on-demand nature. Cloud computing services are hosted in Cloud Data Centers (CDC) that ...deploy thousands of computation, storage, and communication devices leading to high energy utilization and carbon emissions. Renewable energy resources replace fossil fuels based grid energy to effectively reduce carbon emissions of CDCs. Moreover, waste heat generated from electronic components can be utilized in absorption based cooling systems to offset cooling costs of data centers. However, data centers need to be located at ideal geographical locations to reap benefits of renewable energy and waste heat recovery options. Modular Data Centers (MDC) can enable energy as a location paradigm due to their shippable nature. Moreover, workload can be transferred between intelligently placed geographically dispersed data centers to utilize renewable energy available elsewhere with virtual machine migration techniques. However, adoption of aforementioned sustainability techniques and technologies opens new challenges, such as, intermittency of power supply from renewable resources and higher capital costs. In this paper, we examine sustainable CDCs from various aspects to survey the enabling techniques and technologies. We present case studies from both academia and industry that demonstrate favorable results for sustainability measures in CDCs. Moreover, we discuss state-of-the-art research in sustainable CDCs. Furthermore, we debate the integration challenges and open research issues to sustainable CDCs.
Modern Cloud Data Centers exploit virtualization for efficient resource management to reduce cloud computational cost and energy budget. Virtualization empowered by virtual machine (VM) migration ...meets the ever increasing demands of dynamic workload by relocating VMs within Cloud Data Centers. VM migration helps successfully achieve various resource management objectives such as load balancing, power management, fault tolerance, and system maintenance. However, being resource-intensive, the VM migration process rigorously affects application performance unless attended by smart optimization methods. Furthermore, a Cloud Data Centre exploits server consolidation and DVFS methods to optimize energy consumption. This paper reviews state-of-the-art bandwidth optimization schemes, server consolidation frameworks, DVFS-enabled power optimization, and storage optimization methods over WAN links. Through a meticulous literature review of state-of-the-art live VM migration schemes, thematic taxonomies are proposed to categorize the reported literature. The critical aspects of virtual machine migration schemes are investigated through a comprehensive analysis of the existing schemes. The commonalties and differences among existing VM migration schemes are highlighted through a set of parameters derived from the literature. Finally, open research issues and trends in the VM migration domain that necessitate further consideration to develop optimal VM migration schemes are highlighted.
•State-of-the-art application of blockchain for aerospace, defense industries.•Presents opportunities in operations management, supply chain and logistics.•Highlights open research issues and ...challenges for optimizing operations.
Blockchain is a promising and emerging technology that can have immense potential to provide decentralized trust, data security and integrity, traceability, transparency, visibility, and auditability across various areas in the aerospace and defense industries. In this survey, we study how blockchain features, platforms, and architectures can be leveraged to reshape and revolutionize modern aerospace and defense ecosystems and applications. We also provide discussion into key blockchain complementary architectural technologies such as Oracles, IPFS, and Filecoin. Furthermore, we discuss key opportunities and roles for blockchain in aerospace and military applications. We investigate such opportunities by illustrating multiple use case scenarios including battlefield operations management, border protection, swarm assistance for rescue operations, logistics and supply chain management. Moreover, we compare the existing blockchain platforms to analyze their suitability and applicability for aerospace and defense applications. Finally, we identify and discuss several open issues and challenges for the widespread adoption of blockchain in the aerospace and defense industry. These include latency, privacy, regulation and law, large data traffic, smart contract security, and interoperability.
Display omitted
•Cellulose exo-templating process produced cross-linked garnet solid electrolyte.•SHE was prepared using engineered solid electrolyte infused with SIL.•Developed SHE enabled facile Li ...ion transport during operation of SSLMBs at RT.•SHE-based lithium cells exhibited stable platting/stripping for >1000 h.•Cells with SHE, LiMn2O4 cathode, and Li anode demonstrated high cell performance.
The present study probes the effects of microstructurally engineered Ga-LLZO (Li6.25La3Ga0.25Zr2O12) infused with solvated ionic liquid (SIL) as an advanced solid-state hybrid electrolyte (SHE) for application in pseudo-solid state lithium metal batteries (SSLMBs). To obtain unique microstructure, gel impregnated based cellulose exo-templating process (LLZOCET) designed and the product powder was duly characterized by XRD, RAMAN, FTIR, FESEM and TEM. The electrical properties of engineered Ga-LLZO demonstrated a two-fold reduction in grain boundary resistance and improved lithium-ion transport at RT with lower activation energy (Ea = 0.37 eV) compared to conventionally prepared Ga-LLZO (Ea = 0.59 eV) by gel combustion method (LLZOGC). SHE was prepared using sintered Ga-LLZO pellets infused with solvated ionic liquid (SIL). The presence of SIL was found to enhance lithium metal wettability at the electrolyte-anode interface facilitating Li-ion transport. The impedance spectroscopy (EIS) revealed 3D interconnected morphology in LLZOCET electrolyte which offered lowered impedance, higher lithium ionic conductivity (0.215 mS/cm) and lowered electronic conductivity (7.59×10−8 S/cm) at RT compared to LLZOGC. The developed SHE showed stable lithium platting/stripping behaviour for >1350 h without dendritic penetration with critical current density (CCD) of 700 µA/cm2;which was higher than conventional prepared Ga-LLZO (400 µA/cm2). The electrochemical performance was tested in full cells using LiMn2O4 cathode and Li metal as anode and cycled (>500 cycles) at different current densities (0.1–3.0 mA/cm2). At 1C, engineered LLZO demonstrated 94% capacity retention with >98% columbic efficiency. The post-electrochemical analysis revealed no change in cubic phase or morphological degradation even after prolonged cycling. The compiled data thus clearly established that engineering at the microstructural level might be one of the critical steps for the realization of workable SSLMBs.
With the exponential rise in the number of devices, the Internet of Things (IoT) is geared toward edge-centric computing to offer high bandwidth, low latency, and improved connectivity. In contrast, ...legacy cloud-centric platforms offer deteriorated bandwidth and connectivity that affect the quality of service. Edge-centric Internet of Things-based technologies, such as fog and mist computing, offer distributed and decentralized solutions to resolve the drawbacks of cloud-centric models. However, to foster distributed edge-centric models, a decentralized consensus system is necessary to incentivize all participants to share their edge resources. This paper is motivated by the shortage of comprehensive reviews on decentralized consensus systems for edge-centric Internet of Things that elucidates myriad of consensus facets, such as data structure, scalable consensus ledgers, and transaction models. Decentralized consensus systems adopt either blockchain or blockchainless directed acyclic graph technologies, which serve as immutable public ledgers for transactions. This paper scrutinizes the pros and cons of state-of-the-art decentralized consensus systems. With an extensive literature review and categorization based on existing decentralized consensus systems, we propose a thematic taxonomy. The pivotal features and characteristics associated with existing decentralized consensus systems are analyzed via a comprehensive qualitative investigation. The commonalities and variances among these systems are analyzed using key criteria derived from the presented literature. Finally, several open research issues on decentralized consensus for edge-centric IoT are presented, which should be highlighted regarding centralization risk and deficiencies in blockchain/blockchainless solutions.
Smart cities have the potential to overcome environmental problems caused by improper waste disposal by improving human health, protecting the aquatic ecosystem, and reducing air pollution. However, ...today's systems, approaches, and technologies leveraged for waste management are manual and centralized. This fact makes them vulnerable to manipulation and the single point of failure problem. Also, a large portion of the existing waste management systems within smart cities fall short in providing operational transparency, traceability, audit, security, and trusted data provenance features. In this paper, we explore the key role of blockchain technology in managing waste within smart cities as it can offer traceability, immutability, transparency, and audit features in a decentralized, trusted, and secure manner. We discuss the opportunities brought about by blockchain technology in various waste management use cases and application scenarios, including real-time tracing and tracking of waste, reliable channelization and compliance with waste treatment laws, efficient waste resources management, protection of waste management documentation, and fleet management. We introduce a framework that leverages blockchain-based smart contracts to automate the key services in terms of waste management of smart cities. We compare the existing blockchain-based waste management solutions based on important parameters. Furthermore, we present insightful discussions on several ongoing blockchain-based research projects and case studies to highlight the practicability of blockchain in waste management. Finally, we present open challenges that act as future research directions.
Recycling of electronic waste is a rapidly growing global issue that requires proper monitoring and tracing of electronic devices and the business transactions between the stakeholders. The majority ...of current systems that manage electronic devices throughout their supply chain stages are centralized and lack data transparency, immutability, and security. Specifically, such systems are incapable of handling problems like comprehensive coverage of the life cycle of e-products, access control for maintaining data security, reputation-aware selection of stakeholders, and large amounts of data generated during various stages of the supply chain processes. In this paper, we propose a blockchain-based IoT-enabled system for monitoring all post-production business processes, activities, and operations performed on an electronic device. The system is supported by five smart contracts that record the actions of users on the immutable distributed ledger that aid in ensuring that the business processes carried out by the participants are transparent, traceable, and secure. To store large files, such as images of e-waste materials, products, and licenses for stakeholders, we have integrated our system with a distributed storage system. The proposed system is tested on Ethereum blockchain to check the gas consumption of the functions of the smart contracts. The cost and security analysis shows that the proposed system is viable.
Apple mosaic is widely distributed disease throughout the apple growing regions leading to the major adverse effects both qualitatively and quantitatively. Earlier the apple mosaic virus-ApMV was ...regarded as the only causal agent of the disease, but recently a novel virus apple necrotic mosaic virus-ApNMV have been reported as the causal pathogen from various apple growing countries. Accurate diagnosis of disease and detection of ApMV and ApNMV are of utmost importance, because without this ability we can neither understand nor control this disease. Both the viruses are mostly controlled through quarantine, isolation, sanitation and certification programs depending on sensitive and specific detection methods available. Here we review the 100-year progress in research on apple mosaic disease, which includes history, yield losses, causal agents, their genome organization, replication, traditional to recent detection methods, transmission, distribution and host range of associated viruses and management of the disease.
•Apple mosaic disease is widely distributed all over the apple growing regions and decreases fruit yield nearly by 30-50 per cent.•Earlier the apple mosaic virus-ApMV was regarded as the only causal agent of the disease, but recently a novel virus apple necrotic mosaic virus-ApNMV have also been reported•Both ApMV and ApNMV belong to the genus Ilarvirus, and family Bromoviridae and several methods for detecting ApMV and ApNMV have been developed; which ranges from serological to molecular approaches•Both these viruses are transmitted via virus-infected scion/buds grafted onto, a healthy rootstock or an already virus-infected rootstock resulting in infected trees.•Both the viruses are mostly controlled through quarantine, isolation, sanitation and certification programs depending on sensitive and specific detection methods available
Spare parts are essential assets to maintain productivity and operations. A spare part is used for the repair or replacement of failed units. Tracing and tracking of spare parts ownership can help to ...ensure reliable outcomes in terms of manufacturing operations and service delivery. However, today's spare part inventory systems fall short of providing reliable tracing and tracking of spare parts ownership which poses serious threats to their authenticity. Also, current approaches and systems leveraged for spare part inventory management are vulnerable to the single point of failures. In this paper, we propose a blockchain-based smart contract to trace and track the spare parts ownership details from the original equipment manufacturer to the supplier and end-users. We exploit blockchain features to build a secure and trusted spare part inventory system that is tamper-proof, traceable, trackable, accessible immutable, resilient, and reliable. The proposed system integrates decentralized storage of interplanetary file systems (IPFS) to store and share spare parts data. We present algorithms along with their full implementation details. We perform testing and validation of the smart contract. Furthermore, we provide security and cost analysis, and show how the proposed system ensures reliable tracing and tracking of spare parts ownership. We make the smart contract source code publicly available on Github.
PDF
