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Abstract Wood charcoal is a sustainable, renewable, and environmentally friendly material with the use that the acoustic device can produce. Charcoal made of wood waste materials allows for improving indoor acoustical quality. Therefore, this objective of the article is to investigate the sound scattering coefficients of QRD with the perforation ratio of oak wood charcoal elements. Sound scattering coefficient calculated with the measurement of the reverberation time in the reverberation chamber. The calculation results of the scattering coefficient show the growth of scattering in the frequencies - the highest value reached 0.88 (diffuser N7 with charcoal). The effectiveness of diffusers to diffuse sound waves increases as the number of wells grows. The diffuser with 80 % charcoal elements showed a higher scattering coefficient compared to the diffuser without charcoal elements.

New Directive of the European Parliament and of the Council on the promotion of the use of energy from renewable sources enables member states of European Union not only to initiate changes in legislation, but also to set the mandatory requirements for renewable energy sources. Therefore the number and capacity of renewable power sources, especially wind power plants, in Lithuania tend to increase very fast. Beside the main advantages of wind power plants, related to environmental and climate changes requirements, some drawbacks, concerning additional balancing and reserve, could be stated. A lot of questions arise, which are related to operation individualities of wind power plants during steady and fault conditions, influence of wind power plants on the operation of transmission network relay protection and automation.

Summary Both climate warming and biological invasions are prominent drivers of global environmental change and it is important to determine how they interact. However, beyond tolerance and reproductive thresholds, little is known about temperature dependence of invaders’ performance, particularly in the light of competitive attributes of functionally similar native species. We used experimentally derived energy budgets and field temperature data to determine whether anticipated warming will asymmetrically affect the energy budgets of the globally invasive Ponto‐Caspian mysid crustacean Hemimysis anomala and a functionally similar native competitor (Mysis salemaai) whose range is currently being invaded. In contrast to M. salemaai, which maintains a constant feeding rate with temperature leading to diminishing energy assimilation, we found that H. anomala increases its feeding rate with temperature in parallel with growing metabolic demand. This enabled the invader to maintain high energy assimilation rates, conferring substantially higher scope for growth compared to the native analogue at spring‐to‐autumn temperatures. Anticipated warming will likely exacerbate this energetic asymmetry and remove the winter overlap, which, given the seasonal limitation of mutually preferred prey, appears to underpin coexistence of the two species. These results indicate that temperature‐dependent asymmetries in scope for growth between invaders and native analogues comprise an important mechanism determining invasion success under warming climates. They also highlight the importance of considering relevant spectra of ecological contexts in predicting successful invaders and their impacts under warming scenarios.

Construction is a complex activity, characterized by high levels of capital investment, relatively long delivery durations, multitudinous risks and uncertainties, as well as requiring the integration of multiple skills delivering a huge volume of tasks and processes. All of these must be coordinated carefully if time, cost, and quality constraints are to be met. At the same time, construction is renowned for performing poorly regarding sustainability metrics. Construction activity generates high volumes of waste, requires vast amounts of resources and materials, while consuming a significant proportion of total energy generated. Digitalization of the construction workplace and construction activities has the potential of improving construction performance both in terms of business results as well as sustainability outcomes. This is because, to put it simply, reduced energy usage, for example, impacts economic and “green” performance, simultaneously. Firms tinkering with digitalization, however, do not always achieve the hoped-for outcomes. The challenge faced is that a digital transition of construction firms must be carried out at a strategic level—requiring a comprehensive change management protocol. What then does a digital strategy entail? This study puts forward an argument for the combined economic and sustainability dividends to be had from digitizing construction firm activities. It outlines the requirements for achieving digitalization. The elements of a comprehensive digitalization strategy are cataloged, while the various approaches to developing a digitalization strategy are discussed. This study offers practitioners a useful framework by which to consider their own firm-level efforts at digitalization transition.

Positive Energy Districts (PED) are areas within cities that generate more renewable energy than they consume, contributing to cities’ energy system transformation toward carbon neutrality. Since PED is a novel concept, the implementation is very challenging. Within the European Cooperation in Science and Technology (COST) Action, which offers an open space for collaboration among scientists across Europe (and beyond), this paper asks what the needs for supporting the implementation of PEDs are. To answer this, it draws on Delphi process (expert reviews) as the main method alongside the literature review and also uses surveys as supplementary methods to identify the main challenges for developing PEDs. Initial findings reveal seven interacting topics that later were ranked as highest to the lowest as the following: governance, incentive, social, process, market, technology and context. These are interrelated and interdependent, implying that none can be considered in isolation of the others and cannot be left out in order to ensure the successful development of PEDs. The resources that are needed to address these challenges are a common need for systematic understanding of the processes behind them, as well as cross-disciplinary models and protocols to manage the complexity of developing PEDs. The results can be the basis for devising the conceptual framework on the development of new PED guides and tools.

Abstract Caprolactam is the main compound of nylon 6 waste fishing nets (WFNs) and its recovery conserves natural resources, maximizes WFNs economic performance, and closes the circular economy loop of the fishing net industry. Within the framework and as a part of the Healthy Seas’ initiative to clean the oceans from waste fishing nets (WFNs), and to valorise it, this research aims to study the catalytic pyrolysis behaviour of the WFNs extracted from oceans in order to study their potential applications in the energy conversion field. The catalytic pyrolysis experiments of WFNs over ZSM-5 Zeolite catalyst (2.5, 5, 10, 20, 50 wt%) were conducted using thermogravimetry (TG) coupled with Fourier-transform infrared spectroscopy (TG-FTIR) and gas chromatography–mass spectrometry (GC-MS) at different heating rates (5–30 °C/min). Also, the kinetics of ZSM-5/WFNs catalytic pyrolysis was studied by model-free methods (KAS, FWO, and Friedman). In addition, the distributed activation energy model (DAEM) and the independent parallel reaction kinetic model (IPR) combined with the optimization algorithm were used to fit the TGA-DTG experimental data and to calculate the parameters that can achieve the minimum deviation. The TGA results showed that the main decomposition zone was located in the range 342–476 °C with a total weight loss 83-75 wt% (based on the amount of catalyst). Meanwhile, FTIR and GC-MS results manifested that alkyl C–H stretch functional group, carbonyl functional group (C O), and caprolactam (83.15%; at 20 wt% of ZSM-5) are the main groups and volatile compounds in the decomposed WFNs samples. The model-free kinetics analysis showed that all activation energies were estimated at 112 kJ/mol (WFNs) and 158, 230, 197, 201, and 220 kJ/mol for ZSM-5/WFNs samples (2.5, 5, 10, 20, 50 wt%). At the same time, DAEM and IPR models proved a high prediction to fit TG curves at all heating rates. Based on these results, catalytic pyrolysis using 20 wt% of ZSM-5 can be used as a promising technology for extracting caprolactam from WFNs with high yield (83%). The recovered caprolactam can be used in the production of nylon fibres, nylon thin films, carpets, textiles, resins, etc.

Abstract The study analyzes application of Weibull probability distribution methodologies by summarizing wind power density in selected locations. Reliability of determination of Weibull probability density function of shape k and scale c parameters has been analyzed by means of eight methods. For the assessment of reliability of the methodology, root mean square error, coefficient of determination, chi-square test and relative error were calculated. Measurements of wind characteristics have been carried out in the coastal and continental part of the Lithuania. It has been determined that many calculation methods of the probability density function allow obtaining quite reliable results. However, depending on the geographical location of the area, the height from the ground level, and the influence of other factors on the wind power density, some methods are not acceptable, as they give over-large (up 13.44% and more) relative errors. A simulation model has been established to describe the wind power resources of locations with different climate conditions. For calculation Weibull parameters, it has been used 8760 of wind speed hourly data in 2014. The proposed model could be successfully used for the finding the suitable locations for development wind energy in regions which has the similar surrounding settings.

Relying on real options theory, we employ a multistage decision model to analyze the effect of delaying the introduction of emission trading systems (ETS) on power plant investments in carbon capture and storage (CCS) retrofits, on plant operation, and on carbon dioxide (CO2) abatement. Unlike previous studies, we assume that the investment decision is made before the ETS is in place, and we allow CCS operating flexibility for new power plant investments. Thus, the plant may be run in CCS-off mode if carbon prices are low. We employ Monte Carlo simulation methods to account for uncertainties in the prices of CO2 certificates, other inputs, and output prices, relying on a realistic parameterization for a supercritical pulverized coal plant in China. We find that CCS operating flexibility lowers the critical carbon price needed to support CCS investment because it renders CCS investment less irreversible. For a low carbon price path, operating flexibility also implies that delaying the introduction of an ETS hardly affects plant CO2 abatement since the plant operator is better off purchasing emission certificates rather than operating the plant in CCS mode. Interestingly, for low carbon prices we find a U-shaped relation between the length of the delay and the economic value of the plant. Thus, delaying the introduction of an ETS may make investors worse off.