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Based on data from seven different ship types, this paper provides mathematical relationships that allow us to estimate the main and auxiliary engine power of new ships. With these mathematical relationships we can estimate the power of the engine based on the ship’s length (L), gross tonnage (GT) and age. We developed these approaches using simple linear regression, polynomial regression, K-nearest neighbours (KNN) regression and gradient boosting machine (GBM) regression algorithms. The relationships presented here have a practical application: during the pre-parametric design of new ships, our mathematical relationships can be used to estimate the power of the engines so that more environmentally friendly ships may be built. In addition, with the machine learning methodology, the prediction of the main engine (ME) and auxiliary engine (AE) powers used in the numerical calculation of ship-based emissions provides data for researchers working on emission calculations. We conclude that the GBM regression algorithm provides more accurate solutions to estimate the main and auxiliary engine power of a ship than other algorithms used in the study.

Unspecific peroxygenases have attracted interest in synthetic chemistry, especially for the oxidative activation of C−H bonds, as they only require hydrogen peroxide (H2O2) instead of a cofactor. Due to their instability in even small amounts of H2O2, different strategies like enzyme immobilization or in situ H2O2 production have been developed to improve the stability of these enzymes. While most strategies have been studied separately, a combination of photocatalysis with immobilized enzymes was only recently reported. To show the advantages and limiting factors of immobilized enzyme in a photobiocatalytic reaction, a comparison is made between free and immobilized enzymes. Adjustment of critical parameters such as (i) enzyme and substrate concentration, (ii) illumination wavelength and (iii) light intensity results in significantly increased enzyme stabilities of the immobilized variant. Moreover, under optimized conditions a turnover number of 334,500 was reached. [ABSTRACT FROM AUTHOR]

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Background: Transportation systems with multiple modes are effective, economical, and also offer environmental benefits. This paper summarizes the contributions of multimodal and intermodal transportation systems to the progress in green logistics from 2012 to 2022. A literature survey was conducted to determine the characteristic problems in developing sustainable logistics as well as the techniques and approaches to solve them. The study identified research gaps, and the outcomes will provide a reference for researchers in future work. Published work regarding environmental issues, mode combinations, problem formulations, and solution approaches were evaluated. Research gaps were also identified, and the main requirements for future research were proposed. It was shown that intermodal and multimodal transportation problems in the field of green logistics have received substantial attention in existing literature. However, this is the first literature review of the topic that has considered the body of literature published in the last decade. Methods: The researchers conducted a literature survey to gather relevant information on the topic, based on searching and reviewing academic papers, research articles, conference proceedings, and other publications related to multimodal and intermodal transportation systems and their impact on green logistics from 2012 to 2022. The phases of research method followed data collection, data evaluation, identification of research gaps, proposal of main requirements, and offering valuable insights for future research endeavors. Results: The result of this study highlights the key findings, such as increasing focus on environmental consideration in multiple mode of transportation, lack of studies on uncertainty, utilizing sophisticated solution techniques, the need for different mode combinations, and integrating technological developments to the transportation systems. Conclusions: This study shows that while there is a rich body of literature on multimodal and intermodal transportation systems, the focus has predominantly been on economic rather than environmental sustainability. Future research should prioritize environmentally sustainable multi/intermodal transportation systems, exploring multi-objective planning, integrating different vehicle types, and improving meta-heuristics to tackle real-world logistics challenges. [ABSTRACT FROM AUTHOR]

Biocatalysis can be applied in aqueous media and in different non-aqueous solutions (non-conventional media). Water is a safe solvent, yet many synthesis-wise interesting substrates cannot be dissolved in aqueous solutions, and thus low concentrations are often applied. Conversely, non-conventional media may enable higher substrate loadings but at the cost of using (fossil-based) organic solvents. This paper determines the CO2 production—expressed as kg CO2·kg product−1—of generic biotransformations in water and non-conventional media, assessing both the upstream and the downstream. The key to reaching a diminished environmental footprint is the type of wastewater treatment to be implemented. If the used chemicals enable a conventional (mild) wastewater treatment, the production of CO2 is limited. If other (pre)treatments for the wastewater are needed to eliminate hazardous chemicals and solvents, higher environmental impacts can be expected (based on CO2 production). Water media for biocatalysis are more sustainable during the upstream unit—the biocatalytic step—than non-conventional systems. However, processes with aqueous media often need to incorporate extractive solvents during the downstream processing. Both strategies result in comparable CO2 production if extractive solvents are recycled at least 1–2 times. Under these conditions, a generic industrial biotransformation at 100 g L−1 loading would produce 15–25 kg CO2·kg product−1 regardless of the applied media. [ABSTRACT FROM AUTHOR]

Hydrogels are three-dimensional hydrophilic polymeric networks absorbing up to and even more than 90 wt% of water. These superabsorbent polymers retain their shape during the swelling process while enlarging their volume and mass. In addition to their swelling behavior, hydrogels can possess other interesting properties, such as biocompatibility, good rheological behavior, or even antimicrobial activity. This versatility qualifies hydrogels for many medical applications, especially drug delivery systems. As recently shown, polyelectrolyte-based hydrogels offer beneficial properties for long-term and stimulus-responsive applications. However, the fabrication of complex structures and shapes can be difficult to achieve with common polymerization methods. This obstacle can be overcome by the use of additive manufacturing. 3D printing technology is gaining more and more attention as a method of producing materials for biomedical applications and medical devices. Photopolymerizing 3D printing methods offer superior resolution and high control of the photopolymerization process, allowing the fabrication of complex and customizable designs while being less wasteful. In this work, novel synthetic hydrogels, consisting of [2-(acryloyloxy) ethyl]trimethylammonium chloride (AETMA) as an electrolyte monomer and poly(ethylene glycol)-diacrylate (PEGDA) as a crosslinker, 3D printed via Digital Light Processing (DLP) using a layer height of 100 μm, are reported. The hydrogels obtained showed a high swelling degree q ∞m,t ∼ 12 (24 h in PBS; pH 7; 37 °C) and adjustable mechanical properties with high stretchability (εmax ∼ 300%). Additionally, we embedded the model drug acetylsalicylic acid (ASA) and investigated its stimulus-responsive drug release behaviour in different release media. The stimulus responsiveness of the hydrogels is mirrored in their release behavior and could be exploited in triggered as well as sequential release studies, demonstrating a clear ion exchange behavior. The received 3D-printed drug depots could also be printed in complex hollow geometry, exemplarily demonstrated via an individualized frontal neo-ostium implant prototype. Consequently, a drug-releasing, flexible, and swellable material was obtained, combining the best of both worlds: the properties of hydrogels and the ability to print complex shapes. [ABSTRACT FROM AUTHOR]