Non-catalytic and catalytic pyrolysis of two waste electrical and electronic equipment (WEEE) fractions, with two different copper contents (low- and medium-grade WEEE named as LGE and MGE, respectively), were performed using micro- and lab-scale pyrolyzers. This research aimed to fundamentally study the feasibility of chemical recycling of the WEEE fractions via pyrolysis process considering molecular interactions at the interfaces of catalyst active sites and WEEE pyrolyzates which significantly influence the chemical functionality of surface intermediates and catalysis by reorganizing the pyrolyzates near catalytic active sites forming reactive surface intermediates. Hence, Al2O3, TiO2, HBeta, HZSM-5 and spent FCC catalysts were used in in-situ micro-scale pyrolysis. Results indicated that HBeta and HZSM-5 zeolites were more suitable than other catalysts for selective production of aromatic hydrocarbons and BTX. High acidity and shape selectivity of zeotype surfaces make them attractive frameworks for catalytic pyrolysis processes aiming for light hydrocarbons like BTX. Meanwhile, the ex-situ pyrolysis of LGE and MGE were carried out using HZSM-5 in micro- and lab-scale pyrolyzers to investigate the effect of pyrolysis configuration on the BTX selectivity. Although the ex-situ pyrolysis resulted in higher formation of BTX from LGE, the in-situ configuration was more efficient to produce BTX from MGE. © 2022 The Author(s)
In order to successfully integrate biomass pyrolysis oils as starting materials for conventional oil refineries, upgrading of the pyrolysis oils is needed to achieve desired properties, something which can be performed either as part of the pyrolysis process and/or by separate catalytic treatment of the pyrolysis intermediate oil products. In this study, the quality of stem wood-derived pyrolysis oil was improved via ex situ catalytic hydropyrolysis in a bench-scale pyrolyzer (stage 1), followed by catalytic hydro-coprocessing with fossil co-feed in a laboratory-scale high pressure autoclave (stage 2). The effect of pyrolysis upgrading conditions was investigated based on the quality of intermediate products and their suitability for hydro-coprocessing. HZSM-5 and Pt/TiO2 catalysts (400 °C, atmospheric pressure) were employed for ex situ pyrolysis, and the NiMoS/Al2O3 catalyst (330 °C, 100 bar H2 initial pressure) was used for hydro-coprocessing of the pyrolysis oil. The application of HZSM-5 in the pyrolysis of stem wood under a N2 atmosphere decreased the formation of acids, ketones, aldehydes, and furans and increased the production of aromatic hydrocarbons and phenolics (guaiacols and phenols). Replacing HZSM-5 with Pt/TiO2 and N2 with H2 resulted in complete conversion of guaiacols and significant production of phenols, with further indications of increased stability and reduced coking tendencies.
Software development industry is growing rapidly and so are the time and budget constraints getting stringent. After Scrum, the widely adopted agile method, agile practitioners are now shifting towards Kanban due to its effective communication facilitation, transparency and limited work in progress traits. Since, the industry is in transition from scrum to Kanban therefore we don't find many empirical studies yielding results of adopting Kanban. Therefore, in this study we aim to explore more on Kanban teams. Mainly, we aim to find the impact of Kanban team's communication patterns on their iteration performance and quality. The findings revealed that the centralization communication patterns have negative impact on iteration performance and quality of a project. However, small world communication pattern has positive impact on iteration performance and quality of a project.
The notion that information seeking is not always a solitary activity, and that people working in collaboration for information intensive tasks should be studied and supported, has become more prevalent in the recent years than ever before. The field of collaborative information seeking (CIS) is re-emerging, and bringing many researchers and practitioners from various disciplines. This workshop is an effort to gather a small and motivated set of such participants. The workshop will incorporate discussions on theoretical foundations of CIS as well as its applications. It will bring together researchers from both academia and industry, working in the fields of CSCW, CSCL, IR, HCI, and PIM to share their ideas, questions, and opinions on how theories and practices from different domains can be brought together to create a strong and rich path ahead for collaborative information seeking/retrieval/searching as well as collective information synthesis and sense-making.
Absorption modes and the reactivity of nonhalogenated ionic liquids (ILs) at inorganic oxide surfaces of γ-Al2O3, MgO, and SiO2 particles were characterized using multinuclear (11B, 31P, and 29Si) solid-state magic-angle-spinning NMR, FTIR, and Raman spectroscopy. ILs are composed of the trihexyl(tetradecyl)phosphonium cation, [P6,6,6,14]+, and bis(mandelato)borate, [BMB]-, or bis(salicylato)borate, [BScB]-, anions. Spectroscopic measurements were performed on room-temperature (298 K) samples and samples exposed to 15 h at 373 K. The single-pulse 11B NMR data of heated [P6,6,6,14][BMB] mixed with the inorganic oxides showed a significant change in the spectra of the anion for all three oxides. In contrast, no such spectral changes were detected for heated [P6,6,6,14][BScB] mixed with the inorganic oxides. 31P MAS NMR data for the IL/metal oxide systems revealed interactions between [P6,6,6,14]+ and the surfaces of oxides. A significant intensity of 31P CP-MAS NMR signals indicated a low mobility of cations in these systems. The existence of strongly adhered surface layers of ILs on SiO2 particles was also confirmed by 1H-29Si CP-MAS NMR spectroscopy. FTIR and Raman spectroscopic data revealed strong interactions between the anions and the inorganic surfaces, and there is a strong correlation with the data obtained from NMR spectroscopy. Although their chemical structures are rather similar, the [BScB]- anion is more stable than the [BMB]- anion at the inorganic oxide surfaces.
In orthopaedic surgery, cobalt chromium (CoCr) based alloys are used extensively for their high strength and wear properties, but with concerns over stress shielding and bone resorption due to the high stiffness of CoCr. The structural stiffness, principally related to the bulk and the elastic modulus of the material, may be lowered by appropriate design modifications, to reduce the stiffness mismatch between metal/alloy implants and the adjacent bone. Here, 3D printed CoCr and Ti6Al4V implants of similar macro-geometry and interconnected open-pore architecture prepared by electron beam melting (EBM) were evaluated following 26 week implantation in adult sheep femora. Despite higher total bone-implant contact for Ti6Al4V (39 ± 4%) than CoCr (27 ± 4%), bone formation patterns were similar, e.g., densification around the implant, and gradual ingrowth into the porous network, with more bone in the outer half (periphery) than the inner half (centre). Raman spectroscopy revealed no major differences in mineral crystallinity, the apatite-to-collagen ratio, or the carbonate-to-phosphate ratio. Energy dispersive X-ray spectroscopy showed similar Ca/P ratio of the interfacial tissue adjacent to both materials. Osteocytes made direct contact with CoCr and Ti6Al4V. While osteocyte density and distribution in the new-formed bone were largely similar for the two alloys, higher osteocyte density was observed at the periphery of the porous network for CoCr, attributable to slower remodelling and a different biomechanical environment. The results demonstrate the possibility to achieve bone ingrowth into open-pore CoCr constructs, and attest to the potential for fabricating customised osseointegrated CoCr implants for load-bearing applications. Statement of Significance Although cobalt chromium (CoCr) based alloys are used extensively in orthopaedic surgery, stress shielding due to the high stiffness of CoCr is of concern. To reduce the stiffness mismatch between CoCr and bone, CoCr and Ti6Al4V implants having an interconnected open-pore architecture were prepared by electron beam melting (EBM). After six months of submerged healing in sheep, both alloys showed similar patterns of bone formation, with densification around the implant and gradual ingrowth into the porous network. The molecular and elemental composition of the interfacial tissue was similar for both alloys. Osteocytes made direct contact with both alloys, with similar overall osteocyte density and distribution. The work attests to the potential for achieving osseointegration of EBM manufactured porous CoCr implants.
The osteocyte network, through the numerous dendritic processes of osteocytes, is responsible for sensing mechanical loading and orchestrates adaptive bone remodelling by communicating with both the osteoclasts and the osteoblasts. The osteocyte network in the vicinity of implant surfaces provides insight into the bone healing process around metallic implants. Here, we investigate whether osteocytes are able to make an intimate contact with topologically modified, but micrometre smooth (Sa < 0.5 µm) implant surfaces, and if sub-micron topography alters the composition of the interfacial tissue. Screw shaped, commercially pure (cp-Ti) titanium implants with (i) machined (Sa = ~0.2 µm), and (ii) two-step acid-etched (HF/HNO3 and H2SO4/HCl; Sa = ~0.5 µm) surfaces were inserted in Sprague Dawley rat tibia and followed for 28 days. Both surfaces showed similar bone area, while the bone-implant contact was 73 % higher for the acid-etched surface. By resin cast etching, osteocytes were observed to maintain a direct intimate contact with the acid-etched surface. Although well mineralised, the interfacial tissue showed lower Ca/P and apatite-to-collagen ratios at the acid-etched surface, while mineral crystallinity and the carbonate-to-phosphate ratios were comparable for both implant surfaces. The interfacial tissue composition may therefore vary with changes in implant surface topography, independently of the amount of bone formed. Implant surfaces that influence bone to have higher amounts of organic matrix without affecting the crystallinity or the carbonate content of the mineral phase presumably result in a more resilient interfacial tissue, better able to resist crack development during functional loading than densely mineralised bone.
Embedded software is at the core of current and future telecommunication, automotive, multimedia, and industrial automation systems. The success of practically any industrial application depends on the embedded software system's dependability, and one method to verify the dependability of a system is testing its robustness. The motivation behind this paper is to provide a knowledge base of the state of the practice in robustness testing of embedded software systems and to compare this to the state of the art. We have gathered the information on the state of the practice in robustness testing from seven different industrial domains (telecommunication, automotive, multimedia, critical infrastructure, aerospace, consumer products, and banking) by conducting 13 semi-structured interviews. We investigate the different aspects of robustness testing, such as the general view of robustness, relation to requirements engineering and design, test execution, failures, and tools. We highlight knowledge from the state of the practice of robustness testing of embedded software systems. We found different robustness testing practices that have not been previously described. This paper shows that the state of the practice, when it comes to robustness testing, differs between organizations and is quite different from the state of the art described in the scientific literature. For example, methods commonly described in the literature (e.g., the fuzzy approach) are not used in the organizations we studied. Instead, the interviewees described several ad hoc approaches that take specific scenarios into account (e.g., power failure or overload). Other differences we found concern the classification of robustness failures, the hypothesized root causes of robustness failures, and the types of tools used for robustness testing. This paper is a first step in capturing the state of the practice of robustness testing of embedded software systems. The results can be used by both researchers and practitioners. Researchers can use our findings to understand the gap between the state of the art and the state of the practice and develop their studies to fill this gap. Practitioners can also learn from this knowledge base regarding how they can improve their practice and acquire other practices.
An agile software development process is often claimed to increase productivity. However, productivity measurement in agile software development is little researched. Measures are not explicitly defined nor commonly agreed upon. In this paper, we highlight the agile productivity measures reported in literature by means of a research method called scoping study. We were able to identify 12 papers reporting the productivity measures in agile software development processes. We found that finding, understanding and putting into use agile productivity definitions is not an easy task. From the perspective of common roles in agile software development process and existing knowledge workers' productivity dimensions, we also emphasize that none of the productivity measures satisfy these fully. We recommend that future effort should be focused on defining agile productivity in measurable, practicable and meaningful form.
The ability to predict conditional distributions of service metrics is key to understanding end-to-end service behavior. From conditional distributions, other metrics can be derived, such as expected values and quantiles, which are essential for assessing SLA conformance. Our demonstrator predicts conditional distributions and derived metrics estimation in realtime, using infrastructure measurements. The distributions are modeled as Gaussian mixtures whose parameters are estimated using a mixture density network. The predictions are produced for a Video-on-Demand service that runs on a testbed at KTH.
Remanufacturing is one of the main practices toward a circular economy and industrial sustainability. Remanufacturing is highly dependent on how circular products are designed and developed. Remanufacturing can also benefit from automation for efficiency, accuracy and flexibil-ity. This paper, via a multiple case study, connects the three areas of remanufacturing, product design and automation and investigates how circular product design can facilitate automation reman-ufacturing processes. First, circular product design guidelines are discussed with regard to reman-ufacturing. Second, potential areas for automation at three remanufacturers of electric and electronic equipment are pinpointed. Finally, design guidelines are connected to the identified potential automation areas in each remanufacturing process and discussed together. According to our results, the main incentives for automating remanufacturing processes are mainly related to the work environ-ment, efficiency and quality. In addition, several design guidelines can facilitate automated reman-ufacturing processes; for instance, the standardization of components, fasteners and remanufactur-ing tools across different models and brands can also facilitate automated remanufacturing, where products can easily and nondestructively be disassembled by a robot or a machine. © 2021 by the authors.
Product design and development are key to moving towards a circular economy; however, the majority of products and components that are currently recirculated have not been designed for circulation of any sort. Circular economy business models and closing the loop can be functional only if the products and services are designed for circularity. This paper presents a set of generic design guidelines for different circular strategies. The guidelines are then used to map companies' circular product design initiatives in the early stages of product design and development. The guidelines have proved to support decision-making and enhance the circularity of products. The guidelines were developed, validated, and tested at four companies within the Nordic countries through an action research approach. Sourcing raw materials, recycling, and ensuring the robustness of products for the use phase are the most common strategies used by the studied companies. There is an ongoing transition towards other recirculation strategies, such as repair, remanufacture, and reuse. © 2020 by the authors.
A major factor in the continued deterioration of the global environment is unsustainable management of resources that includes the type and quantity of resources consumed and manufactured as well as the subsequent generation and treatment of wasted materials. Improved material efficiency (ME) in manufacturing is key to reducing resource consumption levels and improving waste management initiatives. However, ME must be measured, and related goals must be broken down into performance indicators for manufacturing companies. This paper aims to improve ME in manufacturing using a structured model for ME performance measurements. We present a set of ME key performance indicators (ME-KPIs) at the individual company and lower operational levels based on empirical studies and a structured literature review. Our empirical findings are based on data collected on the performance indicators and material and waste flows of nine manufacturing companies located in Sweden. The proposed model categorizes ME-KPIs into the following categories: productive input materials, auxiliary input materials, output products, and residual output materials. These categories must be measured equally to facilitate the measurement, assessment, improvement and reporting of material consumption and waste generation in a manufacturing context. Required qualities for ME-KPI suggested in literature are also discussed, and missing indicators are identified. Most of the identified ME-KPIs measure quality- and cost-related factors, while end-of-life scenarios, waste segregation and the environmental effects of waste generation and material consumption are not equally measured. Additionally, ME-KPIs must also be connected to pre-determined goals and that defining or revising ME-KPIs requires communication with various external and internal actors to increase employees’ awareness and engagement.
Developments, industrialization and mass production have triggered rapid increase of raw material consumption and great volumes of industrial waste, while industrial waste management infrastructure has not been developed with the same pace. One mean in striving for industrial waste management is the management of process materials. This paper introduces the performance measure sorting rate for each segment of waste material, along with a method for sorting analysis to help improving overall material efficiency and industrial waste management. The results revealed that more than 50% of combustible bins’ content could be separately segregated as plastic, wood, paper, cardboard and bio-degradable.
To achieve sustainable development goals, it is essential to include the industrial system. There are sufficient numbers of tools and methods for measuring, assessing and improving the quality, productivity and efficiency of production, but the number of tools and methods for environmental initiatives on the shop floor is rather low. Incorporating environmental considerations into production and performance management systems still generally involves a top-down approach aggregated for an entire manufacturing plant. Green lean studies have been attempting to fill this gap to some extent, but the lack of detailed methodologies and practical tools for environmental manufacturing improvement on the shop floor is still evident. This paper reports on the application of four environmental assessment tools commonly used among Swedish manufacturing companies—Green Performance Map (GPM), Environmental Value Stream Mapping (EVSM), Waste Flow Mapping (WFM), and Life Cycle Assessment (LCA)—to help practitioners and scholars to understand the different features of each tool, so in turn the right tool(s) can be selected according to particular questions and the industrial settings. Because there are some overlap and differences between the tools and a given tool may be more appropriate to a situation depending on the question posed, a combination of tools is suggested to embrace different types of data collection and analysis to include different environmental impacts for better prioritization and decision-making.
Abstract Improving material efficiency contributes to reduce the volume of industrial waste as well as resource consumption. However, less has been published addressing on what to measure for material efficiency in a manufacturing company. This paper presents the current practice of material efficiency performance indicators in a manufacturing context through a bottom-up approach. In addition to literature review, the empirical data was collected via a multiple case study at seven global manufacturing companies located in Sweden. The results show that existing material efficiency indicators are limited and are mainly measured as a cost or quality parameter rather than environment. The limited number of measurements relates to the fact that material efficiency is not considered as a central business in manufacturing companies and is managed by environmental department with limited correlation to operation. Additionally, these measurements do not aim to reduce waste volume or improve homogeneity of generated waste.
Material efficiency in manufacturing is an enabler of circular economy and captures value in industry through decreasing the amount of material used to produce one unit of output, generating less waste per output and improving waste segregation and management. However, material types and fractions play an important role in successfulness of recycling initiatives. This study investigates two main fractions in automotive industry, namely, metal and plastic. For both material flows, information availability and standards and regulations are pivotal to increase segregation, optimize the collection and obtain the highest possible circulation rates with high quality of recyclables. This paper presents and compares the current information flows and standards and regulations of metals and plastics in the automotive value chain.
Previous environmental studies indicate several barriers to circular economy and material efficiency including a lack of detailed methodologies for manufacturing improvement in terms of environmental and operational performances to measure, monitor and evaluate material consumption and waste generation. A lean and green tool, the green performance map (GPM), is an appropriate tool for different environmental initiatives including training, improvement, reporting and development. Through literature review and multiple case study methodology, this chapter presents the current application of GPM in industry and its usage to regularly measure and monitor material efficiency measurements on different levels and to remove barriers to improved material efficiency.
Improved material efficiency is a key to improve the circular economy and capturing value in industry. Material efficiency reduces the generation of industrial waste, the extraction and consumption of resources, and energy demands and carbon emissions. However, material efficiency in the manufacturing sector, as a means of improving the recyclability, reusability, reduction and prevention of industrial waste, is little understood. This study aims to investigate, on a micro-level, further material efficiency improvement opportunities, barriers and strategies in selected manufacturing companies in Sweden, focusing on increasing waste segregation into high quality circulated raw material. Improvement opportunities at large global manufacturing companies are investigated; barriers hindering material efficiency improvement are identified and categorized at two levels; and strategies that have been deployed at manufacturing companies are reviewed. Empirical findings reveal (1) further potential for improving material efficiency through higher segregation of residual material from mixed and low quality fractions (on average, 26% of the content of combustible waste, in weight, was plastics; 8% and 6% were paper and cardboard, respectively); (2) the most influential barriers are within budgetary, information, management, employee, engineering, and communication clusters; (3) a lack of actual material efficiency strategy implementation in the manufacturing companies. According to our analysis, the majority of barriers are internal and originate within the manufacturing companies, therefore they can be managed (and eradicated if possible) with sufficient resources in terms of man hours, education and investment, better operational and environmental (waste) management, better internal communication and information sharing, and deployment of material efficiency strategies.
It is well known that, quality and properties of many commercial cast steels are strongly related to the microstructure developed during solidification and subsequent processing stages. With the temperature gradient in the meniscus shell covering a wide range of temperature, the resultant situation becomes rather complex. The objective of this research is to increase knowledge of solidification behaviour for industrially important steels. The microstructural evolution during solidification and subsequent solid-state transformation is studied by gradient solidification and quenching methods. Gradient solidification study can be a way of optimization of new steel grade production by understanding how multiphase microstructures are formed and how they can be controlled via deliberate selection of solidification. This research includes sampling by suction with quartz tubes through a syringe and solidification studies of three different carbon and peritectic steels. The phase transformation in the studied steels is precipitation of primary ferrite dendrite followed by peritectic reaction (L+δ →γ) during the gradient solidification and quenching.
In order to cater for user's quality of experience (QoE) requirements, HTTP adaptive streaming (HAS) based solutions of video services have become popular recently. User QoE feedback can be instrumental in improving the capabilities of such services. Perceptual quality experiments that involve humans are considered to be the most valid method of the assessment of QoE. Besides lab-based subjective experiments, crowdsourcing based subjective assessment of video quality is gaining popularity as an alternative method. This paper presents insights into a study that investigates perceptual preferences of various adaptive video streaming scenarios through crowdsourcing based subjective quality assessment.
The second-generation bio aviation fuel production via Chemical Looping Gasification (CLG) of biomass combined with downstream Fischer-Tropsch synthesis is a possible way to decarbonize the aviation sector. Although CLG has a higher syngas yield and conversion efficiency compared to the conventional gasification processes, the fraction of biogenic carbon which is converted to biofuel is still low (around 28%). To increase carbon utilization and biofuel yield, incorporation of two types of electrolyzers, Polymer Electrolyte Membrane (PEM) and Molten Carbonate Electrolysis Cell (MCEC), for syngas conditioning has been investigated. Full chain process models have been developed using an experimentally validated CLG model in Aspen Plus for Iron sand as an oxygen carrier. Techno-economic parameters were calculated and compared for different cases. The results show that syngas conditioning with sustainable hydrogen from PEM and MCEC electrolyzers results in up to 11.5% higher conversion efficiency and up to 8.1 % higher biogenic carbon efficiencies in comparison to the syngas conditioning with water gas shift reactor. The study shows that the lowest carbon capture rates are found in the configurations with the highest biogenic carbon efficiency which means up to 14% more carbon ends up in FT crude compared to the case with conventional WGS conditioning. Techno-economic analysis indicates that syngas conditioning using PEM and MCEC electrolyzers would result in an increase of the annual profit by a factor of 1.4 and 1.7, respectively, when compared to using only WGS reactors.
Unidirectional (UD) carbon fibre reinforced polyvinylidene fluoride (PVDF) was manufactured using a laboratory scale composite line with in-line atmospheric plasma fluorination of carbon fibre surface. The resulting continuous UD carbon fibre reinforced PVDF prepregs were used to fabricate reinforced thermoplastic pipes (RTPs) via filament winding method. Winding angle of ±55° was employed as a preliminary study. The impact of APF treatment of carbon fibres on the hoop tensile strength as well as stiffness of the RTP is presented. Improvements in the mechanical properties of the RTP indicates the ability of stress transfer between the fibres and the matrix through the interface is enhanced and this is due to the improved adhesion between the fibres and the matrix by incorporating APF on the fibre surface.
The newly developed Flow-Viz rheometric system is capable of performing detailed non-invasive velocimetry measurements through industrial stainless steel pipes. However, in order to improve the current design for non-invasive measurements in industrial fluids, pulsed ultrasound sensors need to be acoustically characterized. In this paper, acoustic characterization tests were carried out, with the aim of measuring the ultrasound beam propagation through stainless steel (SS316L) pipes and into water. For these tests, a high-precision robotic XYZ-scanner and needle hydrophone setup was used. Several ultrasound sensor configurations were mounted onto stainless steel pipes, while using different coupling media between the transducer-to-wedge and sensor wedge-to-pipe boundaries. The ultrasound beam propagation after the wall interface was measured by using a planar measuring technique along the beam's focal axis. By using this technique, the output for each test was a 2-D acoustic color map detailing the acoustic intensity of the ultrasound beam. Measured beam properties depicted critical parameters, such as the start distance of the focal zone, focal zone length, Doppler angle, and peak energy within the focal zone. Variations in the measured beam properties were highly dependent on the acoustic couplants used at the different interfaces within the sensor unit. Complete non-invasive Doppler ultrasound sensor technology was for the first time acoustically characterized through industrial grade stainless steel. This information will now be used to further optimize the non-invasive technology for advanced industrial applications.
Safety-critical systems are required to comply with safety standards. These systems are increasingly digitized and networked to an extent where they need to also comply with security and privacy standards. This paper aims to pro-vide insights into how practitioners apply the standards on safety, security or pri-vacy (Sa/Se/Pr), as well as how they employ Sa/Se/Pr analysis methodologies and software tools to meet such criteria. To this end, we conducted a question-naire-based survey within the participants of an EU project SECREDAS and ob-tained 21 responses. The results of our survey indicate that safety standards are widely applied by product and service providers, driven by the requirements from clients or regulators/authorities. When it comes to security standards, practition-ers face a wider range of standards while few target specific industrial sectors. Some standards linking safety and security engineering are not widely used at the moment, or practitioners are not aware of this feature. For privacy engineering, the availability and usage of standards, analysis methodologies and software tools are relatively weaker than safety and security, reflecting the fact that privacy en-gineering is an emerging concern for practitioners.
This work presents a blueprint or set of guidelines for the planning and development of sustainable national centers dealing with the safety of nanomaterials and nanotechnologies toward public health and environment. The blueprint was developed following a methodological approach of EU-wide online survey and workshop with several stakeholders. The purpose was to identify the key elements and challenges in the development and sustainability of a national nanosafety center. The responses were received from representatives of 16 national nanosafety centers across Europe and 44 people from 18 EU member states who represented the stakeholder groups of researchers, academics, industry, regulators, civil society, and consultants. By providing an overview of the organizational design of existing national nanosafety centers across EU and converging demands in the field of nanosafety, the blueprint principally benefits those EU member states who do not have a national nanosafety center, but intend to develop an entity to manage the human health, environmental, ethical, and social concerns/risks toward the growing nationwide activities on engineered nanomaterials, e.g., their production, use or disposal, at national level. © 2020, The Author(s).
The transition towards more plant-based diets is identified as an important measure for limiting dietary climate impact. Plant-based meat analogues (PBMAs) have been proposed as a viable lower carbon alternative to meat, and its market is rapidly growing globally. However, knowledge about the climate impact of PBMAs in relation to other foods is currently limited due to the challenge of comparing life cycle assessments (LCAs) using different methods. The aim of this study was to review the climate impact of PBMAs based on LCAs published up to 2021. Original LCA data were recalculated to harmonize differences in method choices among studies and presented as the climate impact of final products at factory gate. The median climate impact of PBMAs was estimated at 1.7 kg CO2 eq./kg of product with a more than fourfold variation in impact (0.5–2.4 kg CO2 eq./kg product). Climate impact per protein content of the final product varied from 0.4 to 1.2 kg CO2 eq./100 g protein with a median impact of 0.8 kg CO2 eq./100 g protein. Cultivation of raw materials and manufacturing were identified to be responsible for a large proportion of GHG emissions up to factory gate. However, the assessment of climate impact in the production chain was challenged by the level of detail of data provided. A transparent reporting strategy regarding the specific stages in the supply chain, method choices and product information is recommended to facilitate identification of hot spots to target for improved climate performance of future PBMAs and to enable accurate comparisons between studies. It could further be concluded that current scientific knowledge on the climate impact of PBMAs is based on a limited number of LCAs that often rely on a combination of secondary data and collected data at production scale or from pilot-scale production facilities. Future LCAs of PBMAs would benefit from additional assessments of commercial production using region- and site-specific data. © 2023 The Authors
Municipal wastewater treatment plants (WWTPs) could become valuable contributors to a circular economy by implementing the 3R principles (reduce, reuse, and recycle). While reducing the pollution load of sewage is the primary objective of a WWTP, this process generates several potentially valuable byproducts including treated effluent, biogas, and sludge. The effluent can be reused in various end use applications and biogas can be reused as a fuel (for electricity generation, transportation, and cooking) or a chemical feedstock. The sludge can either be directly recycled as soil conditioner or via thermochemical/biochemical processing routes to recover material (e.g., hydrochar), energy (e.g., heat, and syngas), and resource value (phosphorus). This work presents a five-layered assessment framework for quantitatively evaluating the sustainable value of municipal WWTPs by using life cycle assessment (LCA) and life cycle costing assessment (LCCA) tools. In addition, indicators reflecting potential benefits to stakeholders and society arising from investments into municipal WWTPs such as the private return on investment (PROI) and the environmental externality costs to investment ratio (EECIR). The framework is validated in a hypothetical case study where the sustainable value of a circularly managed municipal WWTP is evaluated in situations involving multiple byproduct utilization pathways. Four future circular options (FCOs) are examined for a 50,000 m3/d capacity WWTP treating sewage up to tertiary standards. The FCOs mainly differ in terms of how biogas is reused (to meet the WWTP's internal energy demands, as cooking fuel, or as fuel for city buses after upgrading) and how sludge is recycled (as soil conditioner or by producing hydrochar pellets for electricity generation). The FCO in which treated effluent is reused in industry, biogas is used as cooking fuel, and sludge is used as a soil conditioner provides the greatest sustainable value (i.e., the lowest private costs and environmental externality costs (EEC) together with high revenues), the highest PROI, and the lowest EECIR. The strengths and limitations of the proposed assessment framework are also discussed. © 2022 The Authors
We report new data on the abundance and distribution of n-monocarboxylic acids (n-MCAs) in fine- and coarse-mode aerosols in rural and urban areas of Sweden, and determine their possible sources. Overall, C6-C16 n-MCAs accounted for ~0.5-1.2% of the total PM10 (particulate matter ≤10μm) mass. In general, the C12-C16 fraction was the most abundant (>75%), with the exception of wintertime samples from a rural site, where C6-C11 acids accounted for 65% of the total C6-C16 n-MCA mass. Positive matrix factorization analysis revealed four major sources of n-MCAs: traffic emissions, wood combustion, microbial activity, and a fourth factor that was dominated by semi-volatile n-MCAs. Traffic emissions were important in the urban environment in both seasons and at the rural site during winters, and were a major source of C9-C11 acids. Wood combustion was a significant source at urban sites during the winter and also to some extent at the rural site in both seasons. This is consistent with the use of wood for domestic heating but may also be related to meat cooking. Thus, during the winter, traffic, wood combustion and microbial activity were all important sources in the urban environment, while traffic was the dominant source at the rural site. During the summer, there was considerable day-to-day variation in n-MCA concentrations but microbial activity was the dominant source. The semi-volatile low molecular weight C6-C8 acids accounted for a small (~5-10%) fraction of the total mass of n-MCAs. This factor is unlikely to be linked to a single source and its influence instead reflects the partitioning of these compounds between the gas and particle phases. This would explain their greater contribution during the winter.
The production of renewable energy is key to satisfying the increasing demand for energy without further increasing pollution. Harnessing ocean energy from waves has attracted attention due to its high energy density. This study compares two generations of floating heaving point absorber WEC, WaveEL 3.0 and WaveEL 4.0, regarding their power performance and mooring line fatigue characteristics, which are essential in, e.g., LCoE calculations. The main differences between the two WECs are the principal dimensions and minor differences in their geometries. The DNV software SESAM was used for simulations and analyses of these WECs in terms of buoy heave motion resonances for maximising energy harvesting, motion characteristics, mooring line forces, fatigue of mooring lines, and hydrodynamic power production. The first part of the study presents results from simulations of unit WEC in the frequency domain and in the time domain for regular wave and irregular sea state conditions. A verification of the two WECs’ motion responses and axial mooring line forces is made against measurement data from a full-scale installation. In the second part of the study, the influence of interaction effects is investigated when the WECs are installed in wave parks. The wave park simulations used a fully-coupled non-linear method in SESAM that calculates the motions of the WECs and the mooring line forces simultaneously in the time domain. The amount of fatigue damage accumulated in the mooring lines was calculated using a relative tension-based fatigue analysis method and the rainflow counting method. Several factors that influence the power performance of the wave park and the accumulated fatigue damage of the mooring lines, for example, the WEC distance of the wave park, the sea state conditions, and the direction of incoming waves, are simulated and discussed. The study's main conclusion is that WaveEL 4.0, which has a longer tube than WaveEL 3.0, absorbs more hydrodynamic energy due to larger heave motions and more efficient power production. At the same time, the accumulated fatigue damage in the moorings is lower compared to WaveEL 3.0 if the distance between the WECs in the wave park is not too short. Its motions in the horizontal plane are larger, which may require a larger distance between the WEC units in a wave park to avoid losing efficiency due to hydrodynamic interaction effects.
We propose a novel distributed leader election algorithm to deal with the controller and control service availability issues in programmable networks, such as Software Defined Networks (SDN) or programmable Radio Access Network (RAN). Our approach can deal with a wide range of network failures, especially intermittent network partitions, where splitting and merging of a network repeatedly occur.
In contrast to traditional leader election algorithms that mainly focus on the (eventual) consensus on one leader, the proposed algorithm aims at optimizing control service availability, stability and reducing the controller state synchronization effort during intermittent network partitioning situations. To this end, we design a new framework that enables dynamic leader election based on real-time estimates acquired from statistical monitoring. With this framework, the proposed leader election algorithm has the capability of being flexibly configured to achieve different optimization objectives, while adapting to various failure patterns. Compared with two existing algorithms, our approach can significantly reduce the synchronization overhead (up to 12x) due to controller state updates, and maintain up to twice more nodes under a controller.
For large-scale programmable networks, flexible deployment of distributed control planes is essential for service availability and performance. However, existing approaches only focus on placing controllers whereas the consequent control traffic is often ignored. In this paper, we propose a black-box optimization framework offering the additional steps for quantifying the effect of the consequent control traffic when deploying a distributed control plane. Evaluating different implementations of the framework over real-world topologies shows that close to optimal solutions can be achieved. Moreover, experiments indicate that running a method for controller placement without considering the control traffic, cause excessive bandwidth usage (worst cases varying between 20.1%-50.1% more) and congestion, compared to our approach.
We have studied nanorheological properties (viscosity and shear moduli) of aqueous xanthan solutions, in the oscillation frequency range up to 10 kHz by using magnetic particles that undergo Brownian relaxation and frequency dependent AC susceptibility (ACS). We used two magnetic nanoparticle (MNP) systems with different mean particle sizes of 80 nm and 100 nm. The determined viscosity and shear modulus of the diluted xanthan solutions from the ACS measurement of the two particle systems agree with traditional oscillatory rheological measurements. However, there is a particle size dependency that could be explained by comparing particles sizes with the xanthan microstructure
The presence and distribution of preserved organic matter on the surface of Mars can provide key information about the Martian carbon cycle and the potential of the planet to host life throughout its history. Several types of organic molecules have been previously detected in Martian meteorites1 and at Gale crater, Mars2–4. Evaluating the diversity and detectability of organic matter elsewhere on Mars is important for understanding the extent and diversity of Martian surface processes and the potential availability of carbon sources1,5,6. Here we report the detection of Raman and fluorescence spectra consistent with several species of aromatic organic molecules in the Máaz and Séítah formations within the Crater Floor sequences of Jezero crater, Mars. We report specific fluorescence-mineral associations consistent with many classes of organic molecules occurring in different spatial patterns within these compositionally distinct formations, potentially indicating different fates of carbon across environments. Our findings suggest there may be a diversity of aromatic molecules prevalent on the Martian surface, and these materials persist despite exposure to surface conditions. These potential organic molecules are largely found within minerals linked to aqueous processes, indicating that these processes may have had a key role in organic synthesis, transport or preservation. © 2023, The Author(s).
Infectious diseases are a potential risk for public health and the global economy. Fast and accurate detection of the pathogens that cause these infections is important to avoid the transmission of the diseases. Conventional methods for the detection of these microorganisms are time-consuming, costly, and not applicable for on-site monitoring. Biosensors can provide a fast, reliable, and point of care diagnostic. Nanomaterials, due to their outstanding electrical, chemical, and optical features, have become key players in the area of biosensors. This review will cover different nanomaterials that employed in electrochemical, optical, and instrumental biosensors for infectious disease diagnosis and how these contributed to enhancing the sensitivity and rapidity of the various sensing platforms. Examples of nanomaterial synthesis methods as well as a comprehensive description of their properties are explained. Moreover, when available, comparative data, in the presence and absence of the nanomaterials, have been reported to further highlight how the usage of nanomaterials enhances the performances of the sensor.
The floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of methyl cellulose (MC) and separation of plastics mixtures were investigated in this paper. It was found that the seven plastics can be separated into three groups by using the wetting agent MC. Group one includes POM and PVC. They are depressed at very low MC concentrations. Group two, including PET, PMMA and PC, has an intermediate floatability. Group three (ABS and PS) has a high floatability. They are almost not depressed within the given MC concentration range. In order to understand the mechanism of selective flotation of plastics and the chemical conditioning process, surface chemical factors, such as wettability of plastics and surface tension of flotation medium, and gravity factors, such as particle density and shape, were studied. It was found that the depressing effect of MC on plastics is ascribed mainly to its adsorption on the plastics surfaces. The MC molecules absorbed on plastics expose some of their polar groups oriented towards the aqueous phase, hence making the plastics surfaces hydrophilic. In addition, flotation selectivity for the plastics is dominated not only by wettability of plastics, but also by particle size, density and shape
This paper summerizes the importance of plastic waste recycling and plastic waste separation. Based on an analysis of the physical and chemical characteristics of plastics and plastic waste, the potentials and limitations of several technological processes are discussed. In addition, a review of the surface chemical aspects of plastic flotation is presented. It can be concluded that the flotation of plasics is a fairly flexible technique and could prove to be a useful process for the separation of mixtures of several different types of plastics. however, more research and development effort is required before this technology can be introduced to industry.
In this paper, the floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of alkyl ethoxylated nonionic surfactant (15-S-7) was investigated. It was found that the floatability of all the plastics decreases with the addition of the surfactant; but they are different in floatability and follow the order POM
In this paper, the characteristics of plastics particles in the cutting products and flotation behaviours of plastics were studied. On this basis, the relation of floatability of plastics with surface chemical related factor and gravity factors was derived and discussed. From the results, it was shown that plastics flotation is dominated not only by surface chemical factors, but also significantly by gravity factors. It is suggested that plastics flotation is a combination of froth flotation and gravity separation. According to this relation, the idea of particle control was first applied for the separation of plastics mixture. From the separation results, it can be seen that this method can greatly increase the separation efficiency for flotation separation of plastics mixture
Most lighting is only designed to meet the visual needs in most public library environments in Sweden. Although lighting-related impacts are relevant to six Unite Nations sustainability goals, some important lighting considerations, such as circadian phase disruption, mode and productivity impact, and energy-efficient operation, are missing in current lighting operating practices. Moreover, most of the current lighting asset management practice in public buildings remains "fix it if only it breaks". With respect to people-centric health factors, visual index, and lighting asset energy-efficient operation, this study sublimates lighting into a new perspective. Finally, the suggested comprehensive lighting operating strategies integrating digital twins can help designers and operators in defining the optimal design/control strategy in public-built environments, like public library. Digital twin-based decision-making is expected to be applied to lighting design and control in public spaces that improves visual acuity and comfort, positively impact mood and productivity, and provides recommendations on engagement principles under Environment Social Governance (ESG) framework to asset manager/operators.
We present a machine learning approach that uses a custom Convolutional Neural Network (CNN) for estimating the depth of water pools from multispectral drone imagery. Using drones to obtain this information offers a cheaper, timely, and more accurate solution compared to alternative methods, such as manual inspection. This information, in turn, represents an asset to identify potential breeding sites of mosquito larvae, which grow only in shallow water pools. As a significant part of the world’s population is affected by mosquito-borne viral infections, including Dengue and Zika, identifying mosquito breeding sites is key to control their spread. Experiments with 5-band drone imagery show that our CNN-based approach is able to measure shallow water depths accurately up to a root mean square error of less than 0.5 cm, outperforming state-of-the-art Random Forest methods and empirical approaches.
The fractography of a new grade of zirconia ceramics, known as self-glazed zirconia, was investigated. The as-sintered intact top surface was made with superior smoothness that mimicked the optical appearances of the natural teeth enamel. The beneath surface opposite to this was made hierarchically rough with microscopic pits of the size up to 60. μm together with grain-level roughness of about 2. μm. The three-point bending test of the samples made with the hierarchically rough surface being tensile one demonstrated an average bending strength of 1120. ±. 70. MPa and a Weibull modulus of as high as 18 ascribed to the improved structural homogeneity. Surface topography was found the main origins of crack initiation leading to fracture. The observed unusually predominant transgranular fracture mode of submicron-sized grains disclosed a possible toughening mechanism of disassembling of mesocrystalline grains that differs significantly from the commonly quoted phase transformation toughening of this category of ceramics.
A transient two-fluid model is applied to simulate fluid flow and heat transfer in a nonisothermal water model of continuous casting (CC) tundish. The original liquid in the bath is defined as the first fluid, and the inlet stream, with the temperature variation, is defined as the second fluid. The flow patterns and heat transfer are predicted by solving the three-dimensional (3-D) transient transport equations for each fluid. The results predicted by the two-fluid model make the effect of natural convection more clear compared with the generally used single fluid model k-ε turbulence model.