Flexible and fire-retardant silica/cellulose aerogel using bacterial cellulose nanofibrils as template material

This study explores the possibility of using various silsesquioxane precursors such as (3-aminopropyl) triethoxysilane (APTES), methyltrimethoxysilane (MTMS), and tetraethyl orthosilicate (TEOS) to produce silsesquioxane-bacterial cellulose nanofibre (bCNF) aerogels. Each precursor allowed to customize the aerogel properties, leading to unique properties suitable for various applications requiring lightweight insulative materials. When utilizing APTES as the silsesquioxane precursor, an aerogel capable of over 90% recovery after compression was formed, making them suitable for flexible applications. When MTMS was used as the precursor, the aerogel retained some compression recovery (80%) but had the added property of superhydrophobicity with a contact angle over 160° due to the presence of CH3 functional groups, enabling water-repellence. Finally, TEOS allowed for excellent thermal insulative properties with a low Peak Heat Release Rate (PHRR), making it a promising candidate for fire-resistant applications. The customization of these aerogel materials was attributed to a combination of the chemical composition of the silsesquioxane precursors and the morphology of the coated bacterial cellulose nanofibres (bCNF), such as CH3 groups found in MTMS enabled for superhydrophobicity. Differences in morphology, such as uniform and smooth silsesquioxane coatings when using APTES or a “pearl-necklace” morphology using TEOS, enabled either compression recovery and flexibility or low thermal conduction. This investigation of silsesquioxane-bCNF provides a good understanding of the importance of the choice of precursor effect on insulating aerogel properties.Funder: Swedish Research Council (VR 2019-05650);Full text license: CC BY</p

Towards field deployment of MAVs in adaptive exploration of GPS-denied subterranean environments

Exploration and safe navigation in previously unknown GPS-denied obstructed areas are major challenges for autonomous robots when deployed in subterranean environments. In response, this work establishes an Exploration-Planning framework developed for the real-world deployment of Micro Aerial Vehicles (MAVs) in subterranean exploration missions. The fundamental task for an autonomous MAV to navigate in an unknown area, is to decide where to look while navigating such that the MAV will acquire more information about the surrounding. The work presented in this article focuses around 3D exploration of large-scale caves or multi-branched tunnel like structures, while still prioritizing the Look-Ahead and Move-Forward approach for fast navigation in previously unknown areas. In order to achieve such exploration behaviour, the proposed work utilizes a two-layer navigation approach. The first layer deals with computing traversable frontiers to generate the look ahead poses in the constrained field of view, aligned with the MAV’s heading vector that leads to rapid continuous exploration. The proposed frontier distribution based switching goal selection approach allows the MAV to explore various terrains, while still regulating the MAV’s heading vector. The second layer of the proposed scheme deals with global cost based navigation of the MAV to the potential junction in a multi-branched tunnel system leading to a continuous exploration of partially seen areas. The proposed framework is a combination of a novel frontier goal selection approach, risk-aware expandable grid based path planning, nonlinear model predictive control and artificial potential fields based on local reactive navigation, obstacle avoidance, and control for the autonomous deployment of MAVs in extreme environments.Validerad;2024;Nivå 2;2024-04-02 (joosat);Full text: CC BY License;This article has previously appeared as a manuscript in a thesis.</p

Frontiers in Photoelectrochemical Catalysis: A Focus on Valuable Product Synthesis

Photoelectrochemical (PEC) catalysis provides the most promising avenue for producing value-added chemicals and consumables from renewable precursors. Over the last decades, PEC catalysis, including reduction of renewable feedstock, oxidation of organics, and activation and functionalization of C─C and C─H bonds, are extensively investigated, opening new opportunities for employing the technology in upgrading readily available resources. However, several challenges still remain unsolved, hindering the commercialization of the process. This review offers an overview of PEC catalysis targeted at the synthesis of high-value chemicals from sustainable precursors. First, the fundamentals of evaluating PEC reactions in the context of value-added product synthesis at both anode and cathode are recalled. Then, the common photoelectrode fabrication methods that have been employed to produce thin-film photoelectrodes are highlighted. Next, the advancements are systematically reviewed and discussed in the PEC conversion of various feedstocks to produce highly valued chemicals. Finally, the challenges and prospects in the field are presented. This review aims at facilitating further development of PEC technology for upgrading several renewable precursors to value-added products and other pharmaceuticals. Funder: National Natural Science Foundation of China (No. 22179029); Fundamental Research Funds for the Central Universities (buctrc202324); Young Elite Scientists Sponsorship Program by BAST (BYESS2023093); Youth Innovation Promotion Association CAS and the CAS-TWAS president’s fellowship; MSCA Fellowship; Ca’Foscari University of Venice (SPIN project);CC BY Full text license</p

Traffic-related metals in urban snow cover: A review of the literature data and the feasibility of filling gaps by field data collection

A literature search on traffic related metals in polluted urban snow revealed a significant volume of references representing a substantive knowledge base. The frequently studied metals in urban snow included Zn, Cu, Pb, Cd and Ni. However, comparing metal concentrations across studies proves to be a complex effort due to the variations in site-specific factors among studies, such as traffic intensity, pavement conditions, hydrometeorological conditions, and research method aspects, such as sampling equipment and frequency, and laboratory analytical methods. The literature review indicated that among the commonly studied metals, Zn and Cu indicated potential environmental concerns, and that there was a lack of data on the occurrence and accumulation in snow of antimony (Sb), tungsten (W), and platinum group elements (PGEs). To partly mitigate this knowledge gap, a field study of these elements was carried out by sampling urban roadside snow at six locations with various land use and traffic intensities, focusing on accumulation of these elements in snowbanks along roadways. The results indicated that traffic related activities are the sources of PGEs, W and Sb in roadside snowbanks, as the concentrations of these metals increased with increasing traffic intensity. The mean concentrations of the studied metals followed this descending order: W (0.4 (Reporting limit-RL)–987 μg/l) &gt; Sb (0.1 RL–33.2 μg/l) &gt; Pd (0.02 (RL)–0.506 μg/l) &gt; Rh (0.02 (RL)–0.053 μg/l). In laboratory melted snow, both W and Sb were mostly in the particulate-bound phase, with &lt;25 % in the dissolved phase. For sites with metal concentrations above the detection limit, the regression analysis indicated linear trends in unit area deposition rates of W with time (snow age), described by R2 = 0.94.Validerad;2024;Nivå 2;2024-03-22 (joosat);Full text license: CC BY 4.0; </p

Exploring broad value creation in mining : Corporate social responsibility and stakeholder management in practice

In today's business landscape, corporate social responsibility is important as companies are expected to integrate social and environmental considerations into their operations and interactions with stakeholders. This involves adhering to codes of conduct, producing sustainability reports, and actively engaging with local communities. As a result, sustainable business models have gained prominence, focusing on societal concerns, environmental consciousness, and financial viability. While stakeholder management is recognized as vital in sustainable business models, there remains a gap in understanding how to implement stakeholder management within this business model effectively. This study uses sustainability reports from major mining and mineral firms to explore how stakeholder management practices might be used to benefit a wider variety of stakeholders. It provides information about stakeholder prioritisation, engagement, and sustainability communication strategies. While these companies attempt to address stakeholders&amp;apos; environmental and social concerns, the study recommends a proactive approach that widens stakeholder engagement, includes secondary stakeholders, leverages shared interests, and enhances stakeholder management reporting to maximize the impact of broad stakeholder value creation in sustainable business models to foster sustainable development.Validerad;2024;Nivå 2;2024-04-02 (signyg);Funder: SUN Research School;Full text license: CC BY</p

Optimization of eco-friendly concrete with recycled coarse aggregates and rubber particles as sustainable industrial byproducts for construction practices

In this technology era, sustainable construction practices have become quite imperative. The exploration of alternative materials to reduce the environmental footprint is of paramount importance. This research paper delves into an exhaustive investigation concerning the utilization of recycled coarse aggregates (RCA) and rubber particles (RP) in concrete. It contributes to the growing body of knowledge aimed at fostering sustainable development in the construction industry by reducing waste, promoting recycling, and mitigating the environmental footprint of building materials. The objective of the study is to evaluate the potential benefits and limitations associated with incorporating these materials, thereby providing a sustainable alternative to conventional concrete. In this research, construction and demolition waste were recycled and used as RCA as a fractional switch of natural coarse aggregate (NCA) from 0% to 100%, with an increment of 20% replacement of NCA in concrete. The RP received from discarded tires generated as automobile industry waste were used as a volumetric fractional substitution of sand in concrete from 0% to 20%, with a 5% increment. No pre-treatment for RCA and RP was carried out before their utilization in concrete. A total of 26 mixes, including control concrete without NCA and RP, with a design strength of 40 MPa, were prepared and tested. Concrete mixes were examined for workability, density, mechanical, and durability properties. It was found that the concrete with 60% RCA and 10% RP showed satisfactory results in evaluation with the strength parameters of control concrete, as the compressive strength obtained for this concrete mix is 40.18 MPa, similar to the control mix. The optimization for RCA and RP was conducted using Response Surface Methodology (RSM). The major concern observed was a rise in water absorption with an increase in the percentage replacement of NCA and natural sand by RCA and RP. Findings from the investigation illustrate a promising prospect for the use of RCA and RP in concrete applications, displaying competent mechanical properties and enhanced durability under certain conditions, offering a viable option for environmentally friendly construction practices. However, the research also sheds light on some constraints and challenges, such as the variability in the quality of RCA and the necessity for meticulous quality control to ensure the reliability and consistency of the end product. It is discerned that further refinement in processing techniques and quality assurance measures is pivotal for mainstream adoption of RCA and RP in concrete construction.Validerad;2024;Nivå 2;2024-03-07 (hanlid);Funder: Prince Sattam bin Abdulaziz University (PSAU/2023/R/1444);Full text license: CC BY</p

Artificial Intelligence in Medical Imaging and the Impact on the Radiographer’s profession : a Literature Overview

Introduktion Den artificiella intelligensens framsteg har kommit att spela stor roll vid användningen inom medicinsk bilddiagnostik. Frågor gällande bland annat tillämpning, diagnostik och behandling är ämnen som uppkommit vid diskussionen om den artificiella intelligensens användning inom radiografi. Syfte Syftet var att undersöka rådande kunskapsläge kring implementering av artificiell intelligens kopplat till röntgensjuksköterskans profession. Metod En allmän litteraturöversikt där nio granskade vetenskapliga artiklar valdes och analyserades utifrån likheter och skillnader. Resultat Tre kategorier framträdde - bristande utbildning, oro för ny teknik och AI som diagnostisk framgång visade att röntgensjuksköterskans profession förändras när både utbildning och kompetens ständigt måste hållas uppdaterade för att möta det ökade patientflödet och den snabba teknikutvecklingen kopplat till AI. Slutsats De valda artiklarna visar att AI´s inverkan på röntgensjuksköterskans profession är mångfacetterad vilket kan ge ökad effektivitet men även ökade utmaningar och att detta i takt med den snabba utvecklingen ställer ökade krav på röntgensjuksköterskans kunskap och kompetensutveckling.

Digitalized and Decentralized Open-Cry Auctioning: Key Properties, Solution Design, and Implementation

Open-cry electronic auctions have revolutionized the landscape of high-value transactions for buying and selling goods. Online platforms such as eBay and Tradera have popularized these auctions due to their global accessibility and convenience. However, these centralized auctioning platforms rely on trust in a central entity to manage and control the processing of bids, e.g., the submission time and validity. The use of blockchain technologies for constructing decentralized systems has gained popularity for their versatility and useful properties toward decentralization. However, blockchain-based open-cry auctions, are sensitive to the order of transactions and deadlines which, in the absence of a governing party, need to be provided in the system design. In this paper, we identify the key properties for the development of decentralized open-cry auctioning systems, including verifiability, transaction immutability, ordering, and time synchronization. Three prominent blockchain platforms, namely, Ethereum, Hyperledger Fabric, and R3 Corda were analyzed in terms of their capabilities to ensure these properties for gap identification. We propose a solution design that addresses these key properties and presents a proof-of-concept (PoC) implementation of such design. Our PoC uses Hyperledger Fabric and mitigates the identified gaps related to the time synchronization of this system by utilizing an external component. During the chaincode execution, the creation and submission of bids initiate requests to the time service API. This API service retrieves trusted timestamps from NTP services to obtain accurate bid times. We then analyzed the system design and implementation in the context of the identified key properties. Lastly, we conducted a performance evaluation of the time service and the PoC system implementation in time-sensitive scenarios and assessed its overall performance.Validerad;2024;Nivå 2;2024-05-14 (hanlid);Full text license: CC BY-NC-NDDigiPrimeRemaNe

Game changers: A generative AI prompt protocol to enhance human-AI knowledge co-construction

The democratization of powerful artificial intelligence (AI) tools, including ChatGPT, has sparked the interest of business practitioners given their ability to fundamentally change the way we work. While AI tools are positioned to augment human capabilities, their effective implementation requires the skill to understand where, when and how to best utilize them efficiently. Furthermore, meaningful engagement with the content produced by generative AI (GenAI) necessitates the intricacy of appropriate prompt engineering to optimize the learning process. As the field of GenAI continues to advance, the art of developing impactful prompts has become a necessary skill for harnessing its full potential. This research develops an AI prompting protocol through a constructivist theory lens. Based on the principles of constructivism, where individuals assimilate new knowledge by bridging it with their existing understanding, this research suggests an active engagement process in the human-AI co-construction of knowledge through GenAI. The goal is to empower business managers and their teams to construct effective AI prompts and validate responses, thereby enhancing user interaction, optimizing workflows, and maximizing the potential outcomes of AI chatbots.Full text license: CC BY</p