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Travellers may be exposed to a wide range of different air pollutants during their journeys. In this study, personal exposures within vehicles and during active travel were tested in real-world conditions across nine different transport modes on journeys from London Paddington to Oxford City Centre, in the United Kingdom. The modes tested covered cycling, walking, buses, coaches, trains and private cars. Such exposures are relevant to questions of traveller comfort and safety in the context of airborne diseases such as COVID-19 and a growing awareness of the health, safety and productivity effects of interior air quality. Pollutants measured were particle number (PN), particle mass (PM), carbon dioxide (CO2) and speciated volatile organic compounds (VOCs), using devices carried on or with the traveller, with pumped sampling. Whilst only a relatively small number of journeys were assessed—inviting future work to assess their statistical significance—the current study highlights where a particular focus on exposure reduction should be placed. Real-time results showed that exposures were dominated by short-term spikes in ambient concentrations, such as when standing on a train platform, or at the roadside. The size distribution of particles varied significantly according to the situation. On average, the coach created the highest exposures overall; trains had mixed performance, while private cars and active transport typically had the lowest exposures. Sources of pollutants included both combustion products entering the vehicle and personal care products from other passengers, which were judged from desk research on the most likely source of each individual compound. Although more exposed to exhaust emissions while walking or cycling, the active traveller had the benefit of rapid dilution of these pollutants in the open air. An important variable in determining total exposure was the journey length, where the speed of the private car was advantageous compared to the relative slowness of the coach.

Data Availability Statement: Data available on request due to privacy Copyright © 2023 by the authors. Over the past few years, fuel prices have increased dramatically, and emissions regulations have become stricter in maritime applications. In order to take these factors into consideration, improvements in fuel consumption have become a mandatory factor and a main task of research and development departments in this area. Internal combustion engines (ICEs) can exploit only about 15–40% of chemical energy to produce work effectively, while most of the fuel energy is wasted through exhaust gases and coolant. Although there is a significant amount of wasted energy in thermal processes, the quality of that energy is low owing to its low temperature and provides limited potential for power generation consequently. Waste heat recovery (WHR) systems take advantage of the available waste heat for producing power by utilizing heat energy lost to the surroundings at no additional fuel costs. Among all available waste heat sources in the engine, exhaust gas is the most potent candidate for WHR due to its high level of exergy. Regarding WHR technologies, the well-known Rankine cycles are considered the most promising candidate for improving ICE thermal efficiency. This study is carried out for a six-cylinder marine diesel engine model operating with a WHR organic Rankine cycle (ORC) model that utilizes engine exhaust energy as input. Using expander inlet conditions in the ORC model, preliminary turbine design characteristics are calculated. For this mean-line model, a MATLAB code has been developed. In off-design expander analysis, performance maps are created for different speed and pressure ratios. Results are produced by integrating the polynomial correlations between all of these parameters into the ORC model. ORC efficiency varies in design and off-design conditions which are due to changes in expander input conditions and, consequently, net power output. In this study, ORC efficiency varies from a minimum of 6% to a maximum of 12.7%. ORC efficiency performance is also affected by certain variables such as the coolant flow rate, heat exchanger’s performance etc. It is calculated that with the increase of coolant flow rate, ORC efficiency increases due to the higher turbine work output that is made possible, and the condensing pressure decreases. It is calculated that ORC can improve engine Brake Specific Fuel Consumption (BSFC) from a minimum of 2.9% to a maximum of 5.1%, corresponding to different engine operating points. Thus, decreasing overall fuel consumption shows a positive effect on engine performance. It can also increase engine power output by up to 5.42% if so required for applications where this may be deemed necessary and where an appropriate mechanical connection is made between the engine shaft and the expander shaft. The ORC analysis uses a bespoke expander design methodology and couples it to an ORC design architecture method to provide an important methodology for high-efficiency marine diesel engine systems that can extend well beyond the marine sector and into the broader ORC WHR field and are applicable to many industries (as detailed in the Introduction section of this paper). This research received no external funding.

Microservice architectures exploit container-based virtualized services, which rarely use hardware-based cryptography. A trusted platform module (TPM) offers a hardware root for trust in services that makes use of cryptographic operations. The virtualization of this hardware module offers high usability for other types of service that require TPM functionalities. This paper proposes the design of TPM virtualization in a container. To ensure integrity, different mechanisms, such as attestation and sealing, have been developed for the binaries and libraries stored in the container volumes. Through a REST API, the container offers the functionalities of a TPM, such as key generation and signing. To prevent unauthorized access to the container, this article proposes an authentication mechanism based on tokens issued by the Cognito Amazon Web Service. As a proof of concept and applicability in industry, a use case for electric vehicle charging stations using a microservice-based architecture is proposed. Using the EOS.IO blockchain to maintain a copy of the data, the virtualized TPM microservice provides the cryptographic operations necessary for blockchain transactions. Through a two-factor authentication mechanism, users can access the data. This scenario shows the potential of using blockchain technologies in microservice-based architectures, where microservices such as the virtualized TPM fill a security gap in these architectures., Infineon Technologies, Program “Digitalisierung der Energiewende, Bundesministeriums für Wirtschaft und Energie, Trusted Blockchains fur das offene, intelligente Energienetz der Zukunft (tbiEnergy), FKZ 03EI6029D, European Health and Digital Executive Agency (HaDEA) program under Grant Agreement No 101092950 (EDGELESS project), FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades under Project B-TIC-588-UGR20.

Data Availability Statement: The research data used in the article are based on end-of-course feedback from students, staff meetings, and emails from university management. Therefore, they are confidential and were used with anonymization for data protection. Copyright © 2023 by the authors. Online and distance learning classes have been touted for the last several years as an innovation in higher education that should help improve the entrepreneurial growth mindset of students. However, the reported negative online learning experience of many college students worldwide during the COVID-19 epidemic has shown that many opportunities remain to improve the sustainable development and growth of online visual instruction practices. In this study, we outline and investigate a set of hypotheses related to the perceived usefulness and perceived ease of use (from TAM) of online video instruction in higher education courses during the pandemic. We employ grounded theory using autoethnographic case studies as a data source. We found that (a) synchronous broadcast lectures improve participant attitude (H1) and motivation (H2) toward online instruction, (b) prerecorded video instruction increases participant perceived “ease of use” (H3) and perceived behavioral control (H4) of online instruction, but (c) indicators of recorded dates on pre-recorded video instruction decreases participant perceived “usefulness” (H5) and “certainty” (H6) of online instruction. We enrich the insights of popular motivation models for organizations and the higher education industry by outlining a set of emotional elements originating in neuroscience leadership research (SCARF) that might either amplify or diminish the perceived the ease of use and perceived usefulness to technology usage relationships when participations engage in online learning situations. This research received no external funding.

Gasoline engines employing the spatially distributed auto-ignition combustion mode, known as controlled auto-ignition (CAI), are a prospective technology for significantly improving engine efficiency and reducing emissions. This review paper provides an overview of developments in various gasoline CAI technologies and discusses their attendant strengths and weaknesses. Hybrid propulsion systems powered by high-efficiency gasoline CAI engines can provide a low-carbon pathway for mobility sector decarbonisation. Therefore, this paper focuses on the challenges and opportunities of CAI implementation, especially for electrified powertrains. Different control actuators that can extend the CAI operating range are discussed, and opportunities for synergistic operation between thermal and electric components of hybridised powertrains are identified. Such synergies can remove impediments in the way of CAI system adoption and can, thus, support CAI adoption and maximise efficiency gains from its implementation. The prospects of supporting CAI combustion for different powertrain electrification levels, hybrid architectures, engine size, and energy management systems are discussed. Load levelling offered by electrified powertrains through CAI-favouring energy management strategies has the potential to substantially relax the operating point requirements for CAI-based thermal propulsion units and to remove the need for expensive actuators. The highly flexible spark-assisted partially premixed compression ignition hybrid mode (SACI-PPCI) emerges as a promising CAI strategy for conventional powertrains, and the moderately flexible spark-assisted compression ignition (SACI) configuration can be a cost-effective thermal propulsion mode for electrified powertrains.

With the application of public–private partnership (PPP) model in urban transportation infrastructure projects, various participants have put forward multi-dimensional demands to the operation and maintenance of infrastructures. This study aims to establish a systematic operational performance evaluation framework for PPP transportation infrastructure projects. Based on a literature review, the balanced scorecard was improved, and a conceptual model of multidimensional performance assessment was constructed. The structure of the qualitative performance assessment system was quantified and analyzed by combining structural equation modeling with questionnaires to obtain causal relationships among the indicators. Subsequently, a system dynamics model was constructed to assess the performance dynamically, and a validation analysis was conducted. It finds that maintaining a low level of operational quality over an extended period can significantly reduce stakeholder satisfaction, consequently exacerbating the decline in project performance. In contrast, an improvement in the level of informatization is found to positively contribute to enhancing operational quality and facilitating the long-term sustainability of project operations. It innovatively integrates four dimensions of financial, multi-stakeholder satisfaction, operation and maintenance quality, and sustainability performance to enrich the theoretical system of PPP transportation infrastructure performance assessment. At the same time, it analyzes the influence mechanism among the indicators and its long-term dynamic performance, which provides an effective decision-making tool for operational performance management. Published version

This study set out to identify emerging trends in advancing engineering for sustainable development, supporting the engineering workforce to address wicked problems, and strengthening pathways between engineering education, industry, and policy. The following question guided this work: What are the emerging factors impacting the future of global sustainability efforts within engineering, and how can these be amplified to increase the impact of engineering for sustainable development? Using an adapted Delphi method with surveys, focus groups, and member-checking interviews, we hosted the American Society of Mechanical Engineers (ASME) 2022 Engineering Global Development (EGD) Stakeholder Summit. The summit convened industry leaders, innovators, and academics to explore emerging factors impacting the future of global sustainability efforts in engineering. This manuscript synthesizes emerging trends and proposes recommendations for engineering, particularly in the specific focus area of engineering for sustainable development (e.g., ‘humanitarian engineering’, ‘global engineering’). Critical recommendations include the adoption of emerging cultural mindsets, which include: (1) take an interdisciplinary and multi-stakeholder approach, (2) consider dynamic and interconnected systems, (3) increase humility and intercultural competence, (4) prioritize diversity and inclusion, (5) increase localization and center community perspectives, (6) challenge the perception that engineering is neutral, and (7) broaden the goals of engineering. Ultimately, this study highlights pathways forward for the broader engineering community to more effectively contribute to advancing the United Nations Sustainable Development Goals. Published version

This paper investigates the possibility of using a nanolaminate TiO2/Ag/TiO2 structure as a transparent conductive coating on GaAs solar cells. A novel result is that this structure forms an Ohmic contact to Al-rich AlGaAs, which is used as a “window” layer in GaAs-based solar cells. The TiO2/Ag/TiO2 structure is deposited by RF magnetron sputtering at room temperature. This nanolaminate coating has good optical and electrical properties: a high transmittance of 94% at 550 nm, a sheet resistance of 7 Ω/sq, and a figure of merit (FOM) of 105 × 10−3 Ω−1. These properties are the result of the presence of a discontinuous layer of Ag between two thin layers of TiO2. The morphology of a discontinuous layer of Ag nanogranules is confirmed by the observation of a cross-section of a sample with high-resolution transmission electron microscopy (HRTEM) and EDX analyses. Current–voltage diode characteristics of GaAs solar cells measured under standard test illumination at 1000 W/m2 are analyzed. The formation of an Ohmic contact is explained by the Fermi-level pinning effect caused by nanosized Ag particles in the nanolaminate TiO2/Ag/TiO2 structure. The obtained results demonstrate a new application of oxide−metal−oxide (OMO) coatings as Ohmic contacts to III-V compound semiconductors.

Despite the plethora of explications of the direct and indirect impacts of green people management practices on different dimensions of individual and organizational performance and sustainability, a holistic model demonstrating the constituent aspects and impacts of such sustainability on organizational, individual, and team performance is missing. The objective of this study is to address this gap/void through a review of 127 papers on green human resource management (GHRM) following a systematic literature review approach. Based on the systematic review, this study used a thematic analysis, which identified twenty-four disparate people and organizational aspects and grouped the most used ones into five theoretical lenses, including AMO = ability–motivation–opportunity, RBV = resource-based view, SHT = stakeholder theory, SET =social exchange theory, and SIT = social identity theory. These five sets of results were used to develop the first-of-its-kind holistic framework showing how GHRM works in a cyclical process to fill the missing gap in how to sustainably improve individual, group, and organizational performance for multiple organizational stakeholders. Second, this article contributes theoretically to the social engagement and social identity theories, thereby extending Deci and Ryan’s organismic integration and self-determination theories to show how GHRM practices can be implemented for sustainable organizational performance. Third, this study also proposed a new and more sustainable bottom line for business organizations seeking to improve their performance, and this contribution is referred to as sustainable GHRM-organizational performance (SGHRM-OrgP). Finally, this study proposes a research agenda highlighting where more research areas are needed. Despite the potential that such a model offers for organizational sustainability, the authors recognize the next research step of applying its constituent parts in practically optimizing performance.

The warm-up process is a critical operation phase for micro Combined Heat and Power (mCHP) plants, directly impacting their efficiency, reliability, and lifetime. As small decentralized power generation units are increasingly expected to be operated on demand, start-ups will occur more frequently and thus the importance of the warm-up process will further increase. In this study, we address this problem by presenting a mathematical optimization framework that finds optimal actuator trajectories that significantly reduce the warm-up time and improve the thermal efficiency of an mCHP plant. The proposed optimization framework is highly flexible and adaptable to various objective functions, such as maximizing efficiency or minimizing the deviation from desired temperature references. The underlying mathematical model has been experimentally validated on a physical mCHP test rig. Selected case studies further demonstrate the effectiveness and flexibility of the framework and show that with the optimized actuator trajectories, the mCHP plant can reach its steady-state operating temperature in 40% less time. The results also indicate that the shortest warm-up time does not necessarily lead to the highest thermal efficiency. Accordingly, the methodology proposed in this paper provides a powerful tool to study higher-level operational strategies of mCHP plants and thus to maximize their overall performance, which directly translates into an improved operational cost-effectiveness, particularly in demand-driven energy landscapes., Energies, 16 (10), ISSN:1996-1073

This work proposes a valorization route for spent coffee grounds (SCG), a widespread lignocellulosic residue, encompassing the production of: biomethane, lignin, and oligosaccharides as value-added products obtained simultaneously during a mild alkaline (NaOH) pretreatment. The studied operational variables were the reaction time (60-240 min), temperature (25-75 degrees C), and the NaOH concentration (0-2.5 M). The severity factor suitably describes the global process kinetics, with higher severities (log Mo = 5.5) yielding high product yields, 18.02% and 13.25% (on dry SCG basis) for lignin and oligosaccharides (XGMOS), respectively. Solid yield is negatively impacted by all studied variables (at the 95% confidence level). Conversely, XGMOS yield is positively influenced both by time and catalyst concentration, whereas lignin yield is only (positively) influenced by catalyst concentration. Optimal balance between product formation and potential operational costs is putatively achieved when using 0.625 M NaOH, at 50 degrees C for 60 min. The mild alkaline pretreated biomass (MAP-SCG) was compared to untreated SCG for biomethane production by anaerobic co-digestion with pig slurry (PS), using a ratio of biomass/PS = 1/3 (volatile solids (VS) basis). The proposed valorization route enabled the sequential production of 6.25 kg lignin, 6.36 kg oligosaccharides, and 138.05 kg biomethane per 100 kg of non-extracted SCG (and 287.60 kg pig slurry), in an integrated process that is technically feasible and promotes the circular bioeconomy. info:eu-repo/semantics/publishedVersion

This paper validates the use of a harmonic analysis algorithm on a microcontroller to perform measurements of non-stationary signals in the context of smart grids. The increasing presence of electronic devices such as inverters of distributed generators (DG), power converters of charging stations for electric vehicles, etc. can drain non-stationary currents during their operation. A classical fast Fourier transform (FFT) algorithm may not have sufficient spectral resolution for the evaluation of harmonics and inter-harmonics. Thus, in this paper, the implementation of a chirp-Z transform (CZT) algorithm is suggested, which has a spectral resolution independent from the observation window. The CZT is implemented on a low-cost commercial microcontroller, and the absolute error is evaluated with respect to the same algorithm implemented in the LabVIEW environment. The results of the tests show that the CZT implementation on a low-cost microcontroller allows for accurate measurement results, demonstrating the feasibility of reliable harmonic analysis measurements even in non-stationary conditions on smart grids.

The principal objective of this study is the detailed analysis of the water deficit based on the information gathered by hydrological planning in terms of both the supply of water resources from different sources (surface and groundwater natural sources, transferred from other basins and non-conventional sources based on the reuse of regenerated waters and the desalination of seawater) and the demand for water (urban, agricultural, environmental, industrial, and recreational uses). To do this, the balance between resources and demand is determined, identifying the water deficit and its repercussions, mainly in the agricultural sector. Subsequently, a series of recommendations are proposed that can contribute to the management of water resources in accordance with their origin and availability. The study focuses on the district of Vega Baja del Río Segura, which is located in Southeast Spain, specifically in the Segura River Basin of the province Alicante, and characterized by being one of the European spaces with the greatest structural shortage of water resources. The 27 municipalities, which it constitutes and are the object of analysis in this study, have a semi-arid climate with mild temperatures and scarce torrential rainfall, which generates a continuous situation of water stress and structural shortage. The management of water resources in this area is vitally important for socio-economic development and the maintenance of the natural ecosystems. According to the climate change predictions, this deficit situation is set to worsen, which will aggravate the water imbalance. This research was funded by the Water Chair of the University of Alicante-Alicante Provincial Council (2023) and by the Campus Hábitat5U network of excellence.

Microwave radiation is widely utilized in construction practice, especially for drying building materials, remediating damp masonry, or sterilization of biotic pests that have infested building structures. The available scientific and technical literature reports that certain materials exposed to microwave radiation do not change their physical and mechanical properties, although this has not yet been adequately verified. This paper builds on many years of research in the area, adding to and refining existing information, providing new insights into the mechanical and physical properties of commonly available building materials that have been exposed to controlled microwave radiation, and comparing them with reference values. The experimental research on a set of clay brick samples is carried out using tests according to European standards, and it focuses on the effect of microwave radiation on compressive strength and water absorption. The experimental samples were compared to reference samples that had not been subjected to prolonged exposure to moisture and were subsequently treated with microwave radiation for dehumidification.

The provision of local public services has become one of the main concerns of local governments. Therefore, the selection of the most appropriate form of management to maximize efficiency levels in the provision of local public services has been widely analyzed throughout the academic literature. In this context, the aim of this paper is to add new knowledge to the literature on efficiency in the provision of local public services. To this end, we propose the study of four forms of management (interested indirect management; indirect management by concession; intermunicipal co-operation; public service provision) through a free disposal hull data panel (FDHDP) methodology for the 2014–2016 period. We find that public-private partnership contracting is less efficient on waste removal services when accounting for quality. However, the promised benefits of contracting out are realized when contractors are made responsive to service quality through concessions., Conserjería de Transformación económica, Industria, Conocimiento y Universidades (P20_00605), Ministerio de Ciencia e Innovación (PID2021-12873OB-I00)

In this work, we use an integrated modelling approach to explore the complex relationships and interconnections in marine ecosystems among anthropogenic pressures, biodiversity loss, delivery of ecosystem services (ES), and implemented conservation and management strategies. We selected 60 indicators at regional (34), national (12) and international (14) scales that provided long-term information during the 1985–2019 time frame. The results show a decline in marine biodiversity and its associated provisioning services despite the increasing number of responses delivered by a society which are not enough and/or need more time to exert their effects and highlight the pressure on exploited species of unknown conservation status. The decline in Provisioning ES is explained by the decrease in the overall biomass of the captures, mostly large and carnivorous commercially-targeted species and the increase in the number of small-bodied fish species included in the IUCN Red List. The degradation of ecosystem integrity and the continuing loss of biodiversity affect the ability of the ecosystem to provide Regulating ES. The Cultural ES delivery, related to artisanal fisheries, is better preserved in the Gulf of Cádiz. We conclude how the implementation of new management regulations is needed and should be developed through participatory processes to protect and improve marine ecosystem status, This work was supported by the Biodiversity Foundation (http://www.fundacion-biodiver sidad.es/) of the Spanish Ministry Ecological Transition (Projects: “Evaluación y valoración de los servicios de los ecosistemas marinos de la Red Natura 2000 de España—LIFE15 IP ES012—INTEMARES (FB2017APLI006)” and “Evaluación del impacto de la pesca sobre la biodiversidad marina: un análisis de la dinámica de sus redes tróficas en la Red Natura 2000 de España (CA_BM_2019)”

Synthesis gas (syngas) fermentation is a biological carbon fixation process through which carboxydotrophic acetogenic bacteria convert CO, CO2, and H-2 into platform chemicals. To obtain an accurate overview of the syngas fermentation research and innovation from 2012 to 2022, a systematic search was performed on Web of Science and The Lens, focusing on academic publications and patents that were published or granted during this period. Overall, the research focus was centered on process optimization, the genetic manipulation of microorganisms, and bioreactor design, in order to increase the plethora of fermentation products and expand their possible applications. Most of the published research was initially funded and developed in the United States of America. However, over the years, European countries have become the major contributors to syngas fermentation research, followed by China. Syngas fermentation seems to be developing at "two-speeds", with a small number of companies controlling the technology that is needed for large-scale applications, while academia still focuses on low technology readiness level (TRL) research. This systematic review also showed that the fermentation of raw syngas, the effects of syngas impurities on acetogen viability and product distribution, and the process integration of gasification and fermentation are currently underdeveloped research topics, in which an investment is needed to achieve technological breakthroughs. info:eu-repo/semantics/publishedVersion

Recent evidence available in the literature has highlighted that the high-energy consumption rate associated with air conditioning leads to the undesired “overcooling” condition in arid-climate regions. To this end, this study quantified the effects of increasing the cooling setpoint temperature on reducing energy consumption and CO2 emissions to mitigate overcooling. DesignBuilder software was used to simulate the performance of a generic building operating under the currently adopted ASHRAE HVAC criteria. It was found that increasing the cooling setpoint temperature by 1 °C will increase the operative temperature by approximately 0.25 °C and reduce the annual cooling electricity consumption required for each 1 m2 of an occupied area by approximately 8 kWh/year. This accounts for a reduction of 8% in cooling energy consumption compared to the ASHRAE cooling setpoint (i.e., t_s = 26 °C) and a reduction in the annual CO2 emission rate to roughly 4.8 kg/m2 °C. The largest reduction in cooling energy consumption and CO2 emissions was found to occur in October, with reduced rates of approximately–1.3 kWh/m2 °C and −0.8 kg/m2 °C, respectively. Published version

Walking is the most sustainable means of daily travel for short trip distances and is a key component of the overall transport system. This paper documents variation in walking rates among countries, cities in the same country, and in different parts of the same city. Our international analysis of official government statistics shows that walking rates are highest for short trips, higher for women than for men, decline with increasing income, and remain constant as age increases. Walking fatality rates are much higher in the USA compared with the other countries we examined, both per capita and per km walked. Government policies that would increase walking rates while improving pedestrian safety include: integrated networks of safe and convenient walking infrastructure; roadways and intersections designed for the needs of pedestrians; land-use regulations that encourage mixed uses and short trip distances; lower city-wide speed limits and traffic calming in residential neighborhoods; reduced supply and increased price of parking; traffic laws that give priority to pedestrians; improved traffic education for motorists and non-motorists; tax surcharges on large personal vehicles; and strict enforcement of laws against drink and distracted driving. Five decades of success with these policies in many European cities provide practical examples for car-oriented cities to follow, especially in North America. Published version

The use of biobased heterogeneous catalysts made from agricultural waste for producing biodiesel has gained attention for its potential to create a sustainable and low-cost process. The blending of two or more biomass residues to create more viable biobased catalysts is still in its early stages. In this study, a Biobased Composite Heterogeneous Catalyst (CHC) was made by blending the shells of periwinkle (PWS), melon seed-husk (MSH), and locust bean pod-husk (LBP) at a mixing ratio of 67:17:17 using Simplex Lattice Design Mixture, that was then calcined for 4 h at 800 °C. The chemical, structural, and morphological components of the CHC were characterized via XRF, XRD, SEM-EDX, BET, TGA/DSC, and FTIR to assess its catalytic potential. The CHC was employed to synthesize biodiesel from palm kernel oil, and the process optimization was conducted using the Taguchi approach. The XRF analysis showed that the catalyst had 69.049 of Calcium (Ca) and 9.472 of potassium (K) in their elemental and oxide states as 61.592% calcium oxide and 7.919% potassium oxide. This was also supported by the EDX result, that showed an appreciable value of 58.00% of Ca and 2.30% of magnesium, that perhaps provided the active site in the transesterification reaction to synthesize biodiesel. The morphological and physisorption isotherms via SEM and BET showed mesoporous structures in the CHC that were made up of nanoparticles. A high maximum biodiesel yield of 90.207 wt.% was attained under the optimized process conditions. The catalyst could be reused for up to four cycles, and the biodiesel produced met both ASTM D6751 and EN 14214 standards for biodiesel. This study demonstrates that blending PWS, MSH, and LBP waste materials can produce high-quality biodiesel without the need for additional catalysts.

This article presents a review to provide up-to-date research findings on concentrated photovoltaic (CPV) cooling, explore the key challenges and opportunities, and discuss the limitations. In addition, it provides a vision of a possible future trend and a glimpse of a promising novel approach to CPV cooling based on pulsating flow, in contrast to existing cooling methods. Non-concentrated photovoltaics (PV) have modest efficiency of up to around 20% because they utilise only a narrow spectrum of solar irradiation for electricity conversion. Therefore, recent advances employed multi-junction PV or CPV to widen the irradiation spectrum for conversion. CPV systems concentrate solar irradiation on the cell’s surface, producing high solar flux and temperature. The efficient cooling of CPV cells is critical to avoid thermal degradation and ensure optimal performance. Studies have shown that pulsating flow can enhance heat transfer in various engineering applications. The advantage of pulsating flow over steady flow is that it can create additional turbulence and mixing in the fluid, resulting in a higher heat transfer coefficient. Simulation results with experimental validation demonstrate the enhancement of this new cooling approach for future CPV systems. The use of pulsating flow in CPV cooling has shown promising results in improving heat transfer and reducing temperature gradients. Engineering and Physical Sciences Research Council (EPSRC): EP/T006315/1. Petroleum Technology Development Fund, Nigeria.

Copyright © 2023 by the authors. The frequency diversion in hybrid power systems is a major challenge due to the unpredictable power generation of renewable energies. An automatic generation controller (AGC) system is utilised in a hybrid power system to correct the frequency when the power generation of renewable energies and consumers’ load demand are changing rapidly. While a neural network (NN) model based on a back-propagation (BP) training algorithm is commonly used to design AGCs, it requires a complicated training methodology and a longer processing time. In this paper, a bacterial foraging algorithm (BF) was employed to enhance the learning of the NN model for AGCs based on adequately identifying the initial weights of the model. Hence, the training error of the NN model was addressed quickly when it was compared with the traditional NN model, resulting in an accurate signal prediction. To assess the proposed AGC, a power system with a photovoltaic (PV) generation test model was designed using MATLAB/Simulink. The outcomes of this research demonstrate that the AGC of the BF-NN-based model was effective in correcting the frequency of the hybrid power system and minimising its overshoot under various conditions. The BP-NN was compared to a PID, showing that the former achieved the lowest standard transit time of 5.20 s under the mismatching power conditions of load disturbance and PV power generation fluctuation. This research received no external funding.

Background: Since the World Health Organization (WHO) declared the COVID-19 pandemic in March 2020, many measures have been taken to prevent the spread of the virus. Consequently, many minors have been confined to their homes and have had to subsequently adapt to countless protocol changes. These factors appear to have contributed to post-traumatic stress disorder (PTSD) in many children. Materials and Methods: The authors searched Medline through PubMed and other databases for studies published from 1 December 2019 to 31 December 2021 on the prevalence of PTSD in schoolchildren. The authors used a random-effects model to calculate the pooled prevalence of PTSD. Results: A total of six studies were included in this review. Our results show a pooled prevalence of PTSD of 14% in children and adolescents. Subgroup analyses identify a significantly higher prevalence of PTSD for studies conducted in China and a higher prevalence in boys. The prevalence of PTSD appeared independent of child age or the methodological rigor of the study. Conclusions: Our results suggest that a large number of children may be suffering from PTSD (post-traumatic stress disorder). Public health measures are thus needed to improve children’s mental health during and after the pandemic, so that the suffering is mitigated to prevent long-lasting effects.

Academic contributions on the impact of the Sustainable Development Goals (SDGs) on businesses have grown exponentially in recent years as a result of the importance of the business sector in improving the economy, society and the environment. Through the use of bibliometric methods and taking the Web of Science (WoS) as a reference database, the research aims to analyze the structure of scientific knowledge of the link between the SDGs and the corporate sector, analyzing 2366 documents published between 1992 and 2022. The results show, among other aspects, the accelerated growth rate of the scientific production analyzed since 2015, the use of publications in articles as the main format for disseminating research results, the relevance of the category of Environmental Sciences as the area of study in which most of the scientific production analyzed falls as well as the predominant role of the publishing houses MDPI, Elsevier and Emerald in the publication of scientific documents on the topic under analysis. The research can therefore be of use to both neophyte and experienced researchers who wish to deepen their understanding of the academic knowledge structure of the SDGs in the business world.

Food waste reduction and security are the main concerns of agri-food supply chains, as more than thirty-three percent of global food production is wasted or lost due to mismanagement. The ongoing challenges, including resource scarcity, climate change, waste generation, etc., need immediate actions from stakeholders to develop resilient food supply chains. Previous studies explored food supply chains and their challenges, barriers, enablers, etc. Still, there needs to be more literature on the innovations in supply chains that can build resilient food chains to last long and compete in the post-pandemic scenario. Thus, studies are also required to explore supply chain innovations for the food sector. The current research employed a stepwise weight assessment ratio analysis (SWARA) to assess the supply chain innovations that can develop resilient food supply chains. This study is a pioneer in using the SWARA application to evaluate supply chain innovation and identify the most preferred alternatives. The results from the SWARA show that ‘Business strategy innovations’ are the most significant innovations that can bring resiliency to the food supply chains, followed by ‘Technological innovations.’ The study provides insights for decision makers to understand the significant supply chain innovations to attain resilience in food chains and help the industry to survive and sustain in the long run.

Electric motors play a crucial role in modern industrial and domestic applications. With the trend of more and more electric drives, such as electric vehicles (EVs), the requirements for electric motors become higher and higher, e.g., high power density with good thermal dissipation and high reliability in harsh environments. Many efforts have been made to develop high performance electric motors, such as the application of advanced novel electromagnetic materials, modern control algorithms, advanced mathematical modeling, numerical computation, and artificial intelligence based optimization design techniques. Among many advanced magnetic materials, soft magnetic composite (SMC) appears very promising for developing novel electric motors, thanks to its many unique properties, such as magnetic and thermal isotropies, very low eddy current loss, and the prospect of low-cost mass production. This paper aims to present a comprehensive review about the application of SMC for developing various electric motors for electric drives, with emphasis on those with three-dimensional (3D) magnetic flux paths. The major techniques developed for designing the 3D flux SMC motors are also summarized, such as vectorial magnetic property characterization and system-level multi-discipline robust design optimization. Major challenges and possible future work in this area are also discussed.

Oil and gas (O&G) companies are facing increasing pressure to transform their businesses in order to contribute effectively to the transition from an economy based on fossil fuels to one driven by clean energy technologies. Understanding how O&G companies can define actions to comply with the United Nations’ Sustainable Development Goals (SDGs) and, specifically, how they can generate a positive impact in terms of sustainability through technology innovation becomes relevant in order to guarantee the success of such transformation. To explore this issue, this article analyzes, using a case study research methodology, the sustainability strategy of an O&G company in the Basque Country region (Spain) that is undergoing a profound transformation of its overall business strategy. In particular, the analysis focuses on how the company’s innovation and research and development (R&D) activities and projects related to clean technologies contribute to fulfilling the energy- and non-energy-related SDGs. The main result of the analysis is the identification and characterization of an emerging complex public–private multi-stakeholder business and innovation ecosystem surrounding the O&G company under scrutiny with a clear focus on low-carbon technologies. This ecosystem channels knowledge and innovation synergies and spillovers at the local and regional levels, encouraging green industrial growth in different value chains, and provides insights about how O&G companies can contribute effectively to the SDGs and, at the same time, increase the sustainability of their businesses. This publication was generously supported by the University of Deusto’s Research Results Transfer Office (Deiker) grant “Contrato Programa—Artículos ISI” No. 2023/0009. The authors would like to thank the organizers and sponsors of the IPTC 2022 for the opportunity to present a previous working version of this article. In addition, the Chairs of IPTC 2022 Session “Sustainability Polices, Strategies, and Governance” provided valuable and useful insights during the preparation of the conference proceedings, which definitely helped to improve this research. Various attendees at the IPTC 2022 showed interest in this research and engaged in debates and conversations about it, which helped to enrich the final orientation of this article. The staff of the University of Deusto’s Library provided helpful advice. Last but not least, special thanks to the blind peer reviewers who finally made possible the present article.

Austria is committed to the net-zero climate goal along with the European Union. This requires all sectors to be decarbonized. Hereby, hydrogen plays a vital role as stated in the national hydrogen strategy. A report commissioned by the Austrian government predicts a minimum hydrogen demand of 16 TWh per year in Austria in 2040. Besides hydrogen imports, domestic production can ensure supply. Hence, this study analyses the levelized cost of hydrogen for an off-grid production plant including a proton exchange membrane electrolyzer, wind power and solar photovoltaics in Austria. In the first step, the capacity factors of the renewable electricity sources are determined by conducting a geographic information system analysis. Secondly, the levelized cost of electricity for wind power and solarphotovoltaics plants in Austria is calculated. Thirdly, the most cost-efficient portfolio of wind power and solar photovoltaics plants is determined using electricity generation profiles with a 10-min granularity. The modelled system variants differ among location, capacity factors of the renewable electricity sources and the full load hours of the electrolyzer. Finally, selected variables are tested for their sensitivities. With the applied model, the hydrogen production cost for decentralized production plants can be calculated for any specific location. The levelized cost of hydrogen estimates range from 3.08 EUR/kg to 13.12 EUR/kg of hydrogen, whereas it was found that the costs are most sensitive to the capacity factors of the renewable electricity sources and the full load hours of the electrolyzer. The novelty of the paper stems from the model applied that calculates the levelized cost of renewable hydrogen in an off-grid hydrogen production system. The model finds a cost-efficient portfolio of directly coupled wind power and solar photovoltaics systems for 80 different variants in an Austria-specific context.

The increase in the prices of fossil fuels and environmental issues are leading to a high investment in wind power and solar photovoltaic all over Europe, reducing its dependence on imported fossil fuels. The European countries started incentive programs for investment in these renewable technologies, which consisted of fixed and market premium feed-in tariffs. These feed-in schemes involve long-term contracts with updated prices over inflation. These incentives highly increase the investment and installation of new renewable capacity in Europe. They lead to high renewable penetrations in power systems but originate a tariff deficit due to the difference between market prices and the tariffs paid to these technologies. End-use consumers pay the tariff deficit on retail tariffs. This work analyzes the market-based remuneration of variable renewable energy considering different support schemes and the role of risk-sharing contracts in mitigating the spot price volatility. It presents models able to negotiate bilateral contracts considering risk management, notably risk attitude and risk sharing, bid establishment, and clause (by-laws) negotiation. Furthermore, to evaluate the economic sustainability of renewable generation in Spain, it presents a study for different 12-year support schemes starting in 2010. The results confirmed that, in the case of using risk-sharing contracts during crisis periods, the incidence of low energy prices (price "cannibalization") decreases, such as the tariff deficit. Furthermore, in the case of high-inflation periods, these contracts hedge against the increase in retail prices, resulting in an economic surplus for consumers. info:eu-repo/semantics/publishedVersion

Building information modeling (BIM) has traditionally been considered as a tool for the graphical representation of architectural and engineering projects. This technology has become a key instrument for the development of virtual models that simulate the constructive process and facilitate the analysis of the designed solutions to detect incidents linked to traditional bi-dimensional projects. This article focuses on the use of this technology to optimize the design of MEP (mechanical, electrical, plumbing) facilities and architecture by developing virtual BIM models. Therefore, the purpose of this research is to analyze two experiences of complex buildings that have developed a BIM Execution Plan to improve the coordination of all disciplines involved, in order to explore how these real experiences can contribute to the implementation of the use of this technology in the construction industry. The results of the research are divided into two aspects: on the one hand, the improvements that BIM brings to the coordination and optimization of MEP facilities, linked to the typification of design incidents detected to anticipate conflicts between disciplines, facilitate collaborative design between different agents, keep graphic documentation updated and avoid execution problems and additional costs; and on the other hand, the keys to facilitating the extension of the use of this technology in the industry. Therefore, the conclusions of the research point out to the need for improvement in the automation of incident detection and the reduction in design process deadlines, as well as the need to simplify the virtual modeling process to bring it closer to unqualified personnel involved in the workflow and facilitate the implementation of this technology in the construction industry. TotalBIM Consulting BIM Modeling Team

Coffee, as one of the most consumed beverages, generates a wide variety of waste materials that can be used as biofuels and bio-products. Conventional pyrolysis can be used in rural areas, improving the circular bioeconomy of these places. In this work, the characterization and slow pyrolysis of specialty coffee residues, coffee silverskin (CSS), and spent coffee (SC) were conducted at temperatures from 300 to 600 °C. Physico-chemical and thermal analysis were carried out. In addition, the quantification of individual compounds as acetic, formic, and levulinic acids, caffeine, and other minor compounds was performed. The results indicate the differences between both waste materials in the obtained pyrolysis fractions. The biochar fraction for SC is lower at all temperatures and the liquid fraction higher, reaching maximum values of 62 wt.% in the liquid at 600 °C compared to 47% in CSS. The higher yield in the liquid fraction of SC corresponds to the higher contents of hemicellulose and extractives and the lower ash content. The calculated calorific value for the pyrolysis solid fractions reaches 21.93 MJ/kg in CSS and 26.45 MJ/kg in SC. Finally, biorefinery options of major components of the liquid fraction were also presented. This research was funded by EUROPEAN COMMISSION, Marie Sklodowska-Curie Actions—RISE, grant number 101007733 (CELISE project), by Solvay, under projects 3399 and 3824, and the European LignoCOST Action, number CA17128 (https://lignocost.eu/, accessed on 1 February 2023).

Since WWII to the 2000s, numerous masters of contemporary architecture have contributed to the construction of new landscapes with their works; therefore, these places have become part of a changing landscape and of the multifaceted process of landscape generation. Nevertheless, during this fifty-year period, capitalism has led to the destruction of many existing landscapes, and the policies of protection and preservation have often entailed a process of musealization. In 2000, the European Landscape Convention adopted a new common-grounded definition of landscape, integrating a wide set of cultural approaches and disciplinary topics. Starting from the assumption that contemporary architecture and urban projects can generate high-quality landscapes, this paper investigates the link between the architecture and the landscape, taking the opportunity to catalogue the second half of twentieth-century architecture and urban projects in Sicily as part of the national cataloguing activity “Ereditare il Presente” promoted by the Italian Ministry of Culture. Using the Ministry-proposed cataloguing procedure and adding a quality assessment methodology of buildings and urban projects, this study has produced a theoretical and applicative advancement on how architecture and urban projects of the second half of the twentieth century should be offered as a dynamic component of sustainable human settlement planning under SDG11 “sustainable cities and communities”.

Process heating is the activity with the most energy consumption in the industrial sector. Solar heating (SH) systems are a promising alternative to provide renewable thermal energy to industrial processes. However, factors such as high investment costs and area limitations in industrial facilities hinder their utilization; therefore, hybrid systems that combine two different solar thermal or photovoltaic technologies where each technology operates under conditions that allow a higher overall performance than conventional configurations have been proposed. In this review, we discuss the limitations of conventional SH systems and the potential of hybrid configurations to overcome them. First, the current literature about conventional and hybrid systems is presented. Then, the application of common performance indicators to evaluate hybrid configurations is analyzed. Finally, the limitation, advantages, and potential applications of conventional and hybrid systems are discussed. This work shows that conventional systems are the most promising alternatives in low and high-temperature industrial applications. At the same time, in medium and processes, hybrid configurations have great potential to increase the performance of SH systems and help to boost their adoption in the industrial sector. There are few studies about hybrid systems in industrial applications, and further research is required to determine their potential.

Although consumer attitude towards sustainable food has increased over time, scientific research suggests that more profound comprehension is needed of the social and psychological dimensions that condition consumers’ willingness to purchase food items produced in a sustainable way. The current study attempts to understand the individual motivations that drive conscious consumption, in both the individual and collective spheres, expressed through joining a local social innovation in the food domain. A multi-method design was used, which combined participatory observation, document analysis, and twenty-six in-depth interviews with members of eight local food consumption initiatives located in the Galician region (Spain). The findings reveal that sustainable food purchasing is driven by the individual’s motivation to maintain a healthy diet, pro-environmental and social values, environmental awareness, and attachment to Galician rural areas. Concerning motivations underlying people’s willingness to engage in conscious and responsible consumption initiatives, the first reason relates to the fulfilment of basic needs (affordability and accessibility to organic, low-carbon, and fair-trade goods), followed by sociopolitical goals and the aspiration to satisfying social and psychological needs such as the need for connectedness or the desire for autonomy and control over one’s purchasing decisions.

Funding: This work was carried out thanks to the help received from the “I + D + i” research project entitled: “Is the empowering-disempowering motivational climate that undergraduate students perceive related to their intention to become teachers? A longitudinal study with teachers in training” (Ref. P20_00148), funded by the Andalusian Plan for Research, Development, and Innovation (PAIDI, 2020) of the Junta de Andalucía and help to research projects from the Health Research Center of the University of Almería. As well, this article was carried out during a research stay of Dr. Antonio Granero-Gallegos at the University of Granada (from 14 October 2022, to 14 January 2023) with Dr. Antonio Baena-Extremera., Academic self-concept plays a determining role in the teacher education process. Although research in education has focused on understanding the mechanisms that produce higher academic effort and academic self-confidence, the role that satisfaction and frustration of basic psychological needs and social support and resilience might play on academic self-concept is not known. The aim of the present study was to analyse the mediating effect of social support and resilience in the relationship between satisfaction/frustration of basic psychological needs and academic confidence and academic effort. A non-experimental, cross-sectional, correlational-causal study was designed. In total, 328 Physical Education pre-service teachers (131 women; 197 men) participated from eight Andalusian public universities. The age ranged from 22 to 45 years (M = 24.83; SD = 3.57). The following scales were used: Basic Psychological Needs Satisfaction in Education, Basic Psychological Needs Frustration in Education, Resilience, Social Support, and Academic Self-concept. A structural equations analysis with latent variables was carried out and the results obtained show that the satisfaction of basic psychological needs predicts an improvement in academic confidence and academic effort. In addition, resilience and social support significantly mediated the relationship between satisfaction of basic psychological needs and academic self-concept. This research also highlights the importance, both for teachers and researchers, of creating a context for encouraging the satisfaction of basic psychological needs, to promote academic self-concept in initial teacher training, Andalusian Plan for Research, Development, and Innovation (PAIDI, 2020) of the Junta de Andalucía and help to research projects from the Health Research Center of the University of Almería., University of Granada

One approach to reducing the environmental footprint of conventional polymers is to compound them with bio-based fillers. Plant-based materials have already been successfully used as polymer fillers. In this context, algae-based fillers received minor attention. Due to their unique growth efficiency and ability to capture large amounts of CO2, the use of algae-based fillers could have economic and ecologic advantages. In this work, a possible use of algae as a sustainable filler for filament materials was technologically evaluated. In practical investigations, conventional polyethylene-terephthalate-glycol (PETG) was mixed with the microalgae spirulina platensis and chlorella vulgaris and extruded to 3D printing filaments. Based on printed test specimens and material samples, the printability, mechanical, and thermal properties of the composite were determined. Filaments with a homogeneous distribution of algae particles and stable diameters up to a filler content of 30 wt.% could be produced. All filaments had good printability and adequate moisture sensitivity for higher algae contents. For 30 wt.% the tensile strength of the produced filaments decreases from 54 MPa to 24 MPa, the flexural strength decreases from 87 MPa to 69 MPa, and the material operating temperature decreases slightly from 70 °C to 66 °C. The addition of smaller amounts of algae results in minor changes regarding the overall performance. The properties of the material were comparable to those of other natural fillers such as wood, bamboo or cork. The main objective of adding bio-based materials to polymeric matrices can be achieved. Our results suggest that algae-based filaments can be produced as a more sustainable and low-cost material.

The European heating sector is currently heavily dominated by fossil fuels. Composting is a naturally occurring process in which heat is liberated from the composting substrate at a higher rate than the process needs to support itself. This difference could be harnessed for low-heat applications such as residential consumption, alleviating some of the impacts fossil fuel emissions represent. In this study, the composting heat recovery reported in the literature was compared to the energy demand for space and water heating in four European countries. A review of potential heat production from the waste representative of the residential sector was performed. We found that the theoretically recoverable composting heat does not significantly reduce the need for district heating. However, it can significantly reduce the energy demand for water heating, being able to supply countries such as Greece with between 36% and 100% of the yearly hot water demand, or 12% to 53% of the yearly hot water of countries such as Switzerland, depending on the efficiency of heat recovery.

Airport terminals worldwide generate approximately 6 million tons of passenger waste annually. Increased awareness of climate change and global interventions for environmental sustainability requires a reassessment of airports’ current methods of waste management. This paper proposes a new design concept solution called circular airport retail waste management (CAWM) for airport terminal retail waste processing, which aims to reduce and ideally eliminate airport waste ending up in landfill or incineration. Given the need for novelty and challenging the status-quo, the double diamond design process was adopted as the research method. The research began by collating the current practices of retail waste processing in airports via a literature review and field observations. Secondly, a critical analysis of the current processes was conducted to identify the intervention points. Thirdly, a concept solution was developed based on the circular economy (CE) 9R framework. Finally, the CAWM concept was delivered to airport waste management personnel for review. CAWM offers a structured way of airport retail waste management practices, including the segregation of nonrecyclable and recyclable waste (i.e., different bin designs, color coding, harmonization of waste colors, improved instructions and signage, various bin locations, training, and installing more liquid disposal and donation stations). Airports can leverage CAWM for greater efficiency and cost-effectiveness regarding airport terminal waste processing, such that more waste can be diverted from incineration and landfill to recovery, which will subsequently help airports achieve net-zero targets. This research contributes to the extant CE literature, especially in the aviation industry context, where the academic discourse surrounding this subject and its peculiarities are limited.

The annual yield of bifacial photovoltaic systems is highly dependent on the albedo of the underlying soil. There are currently no published data about the albedo of red soil in western Africa. In this study, the impact of the albedo of red soil in Ghana on the energy yield of bifacial photovoltaic systems is analysed. A bifacial photovoltaic simulation model is created by combining the optical view factor matrix with an electrical output simulation. For an exact simulation, the albedo of red soil at three different locations in Ghana is measured for the first time. The average albedo of every red soil is clearly determined, as well as the measurement span including instrumentation uncertainty; values between 0.175 and 0.335 were measured. Considering these data, a state-of-the-art bifacial photovoltaic system with an average of 19.8% efficient modules in northern Ghana can achieve an annual energy yield of 508.8 kWh/m2 and a bifacial gain of up to 18.3% in comparison with monofacial photovoltaic panels. To summarise, red soil in two out of three locations in Ghana shows higher albedo values than most natural ground surfaces and therefore positively impacts the annual yield of bifacial photovoltaic systems.

The only strategy for reducing fossil fuel-based energy sources is to increase the use of sustainable ones. Among renewable energy sources, solar energy can significantly contribute to a sustainable energy future, but its discontinuous nature requires a large storage capacity. Due to its ability to be produced from primary energy sources and transformed, without greenhouse gas emissions, into mechanical, thermal, and electrical energy, emitting only water as a by-product, hydrogen is an effective carrier and means of energy storage. Technologies for hydrogen production from methane, methanol, hydrocarbons, and water electrolysis using non-renewable electrical power generate CO2. Conversely, employing photoelectrochemistry to harvest hydrogen is a sustainable technique for sunlight-direct energy storage. Research on photoelectrolysis is addressed to materials, prototypes, and simulation studies. From the latter point of view, models have mainly been implemented for aqueous-electrolyte cells, with only one semiconductor-based electrode and a metal-based counter electrode. In this study, a novel cell architecture was numerically modelled. A numerical model of a tandem cell with anode and cathode based on metal oxide semiconductors and a polymeric membrane as an electrolyte was implemented and investigated. Numerical results of 11% solar to hydrogen conversion demonstrate the feasibility of the proposed novel concept. This research was funded by the European Union’s Horizon 2020 research and innovation program under grant agreement ID 760930 (FotoH2 project).

The analysis of reliable studies helps to identify the credibility, scope, and limitations of various techniques for condition monitoring of a wind turbine (WT) system’s design and development to reduce the operation and maintenance (O&M) costs of the WT. In this study, recent advancements in data-driven models for condition monitoring and predictive maintenance of wind turbines’ critical components (e.g., bearing, gearbox, generator, blade pitch) are reviewed. We categorize these models according to data-driven procedures, such as data descriptions, data pre-processing, feature extraction and selection, model selection (classification, regression), validation, and decision making. Our findings after reviewing extensive relevant articles suggest that (a) SCADA (supervisory control and data acquisition) data are widely used as they are available at low cost and are extremely practical (due to the 10 min averaging time), but their use is in some sense nonspecific. (b) Unstructured data and pre-processing remain a significant challenge and consume a significant time of whole machine learning model development. (c) The trade-off between the complexity of the vibration analysis and the applicability of the results deserves further development, especially with regards to drivetrain faults. (d) Most of the proposed techniques focus on gearbox and bearings, and there is a need to apply these models to other wind turbine components. We explain these findings in detail and conclude with a discussion of the main areas for future work in this domain.

Deformations affect the structural integrity of wind turbine towers. The health of such structures is thus assessed by monitoring. The majority of sensors used for this purpose are costly and require in situ installations. We investigated whether Multiple-Input Multiple-Output Synthetic Aperture Radar (MIMO-SAR) sensors can be used to monitor wind turbine towers. We used an automotive-grade, low-cost, off-the-shelf MIMO-SAR sensor operating in the W-band with an acquisition frequency of 100 (Formula presented.) to derive Line-Of-Sight (LOS) deformation measurements in ranges up to about 175 (Formula presented.). Time series of displacement measurements for areas at different heights of the tower were analyzed and compared to reference measurements acquired by processing video camera recordings and total station measurements. The results showed movements in the range of up to 1 (Formula presented.) at the top of the tower. We were able to detect the deformations also with the W-band MIMO-SAR sensor; for areas with sufficient radar backscattering, the results suggest a sub-mm noise level of the radar measurements and agreement with the reference measurements at the mm- to sub-mm level. We further applied Fourier transformation to detect the dominant vibration frequencies and identified values ranging from 0.17 to 24 (Formula presented.). The outcomes confirmed the potential of MIMO-SAR sensors for highly precise, cost-efficient, and time-efficient structural monitoring of wind turbine towers. The sensors are likely also applicable for monitoring other high-rise structures such as skyscrapers or chimneys., Energies, 16 (3), ISSN:1996-1073

The efficiency of Hybrid Electric Vehicles (HEVs) may be substantially increased if the energy of the exhaust gases, which do not complete the expansion inside the cylinder of the internal combustion engine, is efficiently recovered by means of a properly designed turbogenerator and employed for vehicle propulsion; previous studies, carried out by the same authors of this work, showed a potential hybrid vehicle fuel efficiency increment up to 15% by employing a 20 kW turbine on a 100 HP rated power thermal unit. The innovative thermal unit here proposed is composed of a supercharged engine endowed with a properly designed turbogenerator, which comprises two fundamental elements: an exhaust gas turbine expressly designed and optimized for the application, and a suitable electric generator necessary to convert the recovered energy into electric energy, which can be stored in the on-board energy storage system of the vehicle. In these two parts, the realistic efficiency of the innovative thermal unit for hybrid vehicle is evaluated and compared to a traditional turbocharged engine. In Part 1, the authors present a model for the prediction of the efficiency of a dedicated radial turbine, based on a simple but effective mean-line approach; the same paper also reports a design algorithm, which, owing to some assumptions and approximations, allows a fast determination of the proper turbine geometry for a given design operating condition. It is worth pointing out that, being optimized for quasi-steady power production, the exhaust gas turbine considered is quite different from the ones commonly employed for turbocharging application; for this reason, and in consideration of the required power size, such a turbine is not available on the market, nor has its development been previously carried out in the scientific literature. In the Part 2 paper, a radial turbine geometry is defined for the thermal unit previously calculated, employing the design algorithm described in Part 1; the realistic energetic advantage that could be achieved by the implementation of the turbogenerator on a hybrid propulsion system is evaluated through the performance prediction model under the different operating conditions of the thermal unit. As an overall result, it was estimated that, compared to a reference traditional turbocharged engine, the turbocompound system could gain vehicle efficiency improvement between 3.1% and 17.9%, depending on the output power level, while an average efficiency increment of 10.9% was determined for the whole operating range.

This perspective article aims to identify key research priorities to make the waste-to-energy sector compatible with the societal goals of circularity and carbon neutrality. These priorities range from fundamental research to process engineering innovations and socio-economic challenges. Three focus areas are highlighted: (i) the optimization of flue gas cleaning processes to minimize gaseous emissions and cross-media, (ii) the expansion of process control intelligence to meet targets for both material recovery and energy recovery, and (iii) climate neutrality, with the potential for negative emissions via the removal of atmospheric carbon dioxide across the full cycle of the waste resource. For each area, recent research trends and key aspects that are yet to be addressed are discussed.

This work evaluated the effects of condensable syngas impurities on the cell viability and product distribution of Butyribacterium methylotrophicum in syngas fermentation. The condensates were collected during the gasification of two technical lignins derived from wheat straw (WST) and softwood (SW) at different temperatures and in the presence or absence of catalysts. The cleanest syngas with 169 and 3020 ppmv of H2S and NH3, respectively, was obtained at 800 degrees C using dolomite as catalyst. Pyridines were the prevalent compounds in most condensates and the highest variety of aromatics with cyanide substituents were originated during WST lignin gasification at 800 degrees C without catalyst. In contrast with SW lignin-based condensates, the fermentation media supplemented with WST lignin-derived condensates at 1:100 vol. only supported residual growth of B. methylotrophicum. By decreasing the condensate concentration in the medium, growth inhibition ceased and a trend toward butyrate production over acetate was observed. The highest butyrate-to-acetate ratio of 1.3 was obtained by supplementing the fermentation media at 1:1000 vol. with the condensate derived from the WST lignin, which was gasified at 800 degrees C in the presence of olivine. B. methylotrophicum was able to adapt and resist the impurities of the crude syngas and altered its metabolism to produce additional butyrate. info:eu-repo/semantics/publishedVersion

Doha, the capital of the State of Qatar, has seen rapid growth in recent years, resulting in challenges that can be addressed through sustainable urban design strategies. Such approaches, including Transit-Oriented Development, aim to provide compact urban forms with mixed-use development enabling easy access to the city’s transit services. In light of such objectives, and with the 2022 World Cup being hosted in Qatar, the government has invested heavily in its public transportation system and in implementing Transit-Oriented Development. This work presents an analysis of the current status of Transit-Oriented Development in the knowledge hub in Doha known as Education City. A case study methodology was used, which included site observation, photographic documentation, mapping, and statistical analysis based on recent census data. The analysis shows that the use of public transportation throughout the site is relatively low, largely due to the region’s hot climate and the local mobility culture, in which there is a general preference for private vehicle use. The culmination of this investigation is a master plan for the study area, which foresees further enhancement of the area while still holding to the aims of Transit-Oriented Development. To this end, key recommendations for modifying the prevailing mobility culture are suggested, such as increasing the availability of multimodal transportation in order to improve public transportation functionality and modifying certain aspects of the public transportation system so that it is convenient and comfortable, even during periods of very hot weather. The findings of this study highlight the potential of urban design to change people’s behavior and increase awareness of multimodal transport options. This research study was developed under the grant scheme awarded by (i) Qatar University [QU]: Grant ID: QUCP-CENG-2021-2 [NATIONAL CAPACITY BUILDING PROGRAM-NCB-S1], titled: Re-thinking a Framework for the Urban Regeneration and Preservation of the Transit Villages of Old Salata, QNM, Msheireb and Souq Waqif.

This paper aims to provide a framework for creating and analyzing cultural heritage games, with the intention of maximizing players’ cognitive, emotional, and behavioral engagement with digital heritage. To achieve this, a set of game design characteristics was identified through semi-structured interviews with experts (n = 16) and subsequently validated through a discussion with university students (n = 19). Grounded theory was then applied to the comments of the experts to create a framework of ten fundamental characteristics, divided into three dimensions: cognitive, emotional, and behavioral. Additionally, an assessment of the literature was conducted to explain and support the inclusion of each game component., Spanish Government FPU20/00281