Secondary Production Processes Research Articles

Assessing the Global Sustainability Impact of Improving the Secondary Steel Production: Lessons Learned from an Italian Steel Plant

This study presents a comprehensive sustainability assessment of a series of technical interventions aimed at improving a secondary steel production process using the Electric Arc Furnace (EAF) technology in a steel plant located in northern Italy. The assessment covers the environmental, social, and economic dimensions of sustainability by considering three sets of indicators and employing a multi-criteria decision-making approach. The results show that the considered interventions can lead to significant improvements in the sustainability performance of the EAF process. The study also highlights the trade-offs and synergies among the sustainability dimensions and provides recommendations for decision-makers to promote sustainable practices in the steel industry. Overall, this study underscores the importance of addressing the sustainability challenges faced by energy-intensive industries such as steel production.

Secondary particle predictions in quasifree proton scattering reactions in the 100–250 MeV energy range

Results for observables related to the secondary particle production process in proton-nucleus spallation reactions at low beam incident energy (100--250 MeV) are shown. The energy and angular distributions of the residual nucleus are determined in the context of our multicollisional Monte Carlo intranuclear cascade model. The mechanism of proton-nucleus reactions is conventionally described as a sequence of two stages: the rapid intranuclear cascade phase and the slow particle evaporation step. In this work we focus on the rapid phase considering the nucleon effective mass as an effect of the many-body nuclear interactions and the intranuclear mean field. This procedure represents a more realistic scenario to obtain the particles' multiplicity generated in spallation reactions with light-mass target nuclei in a low-energy range. We focused our attention on target nuclei of macro elements, such as carbon, oxygen, phosphorus, sulfur, sodium, potassium, chlorine, and calcium, and trace elements such as iron, copper, zinc, bromine and selenium, which are the most frequent compounds of the organic material. The choice of these target nuclei is due to our expectancy that our results can work as a preliminary insight for further theoretical approaches, specially taking into account nuclear effects due to the interaction of the particles of the beam with the organic tissue.

Life cycle assessment of post-demolition autoclaved aerated concrete (AAC) recycling options

Autoclaved aerated concrete (AAC) is a widely used building material for masonry units, prefabricated reinforced components, and lightweight mineral insulation boards. Its low thermal conductivity and good fire resistance increase its popularity in residential buildings. Thus, post-demolition wastes are expected to increase in the future. However, post-demolition AAC (pd-AAC) is mainly disposed in landfills while landfill capacities decrease and legal framework conditions in Europe are tightening. This study performed life cycle assessments (LCA) of different pd-AAC recycling options and compared them to each other and to current landfilling to identify the best end-of-life handling of pd-AAC from an ecological perspective. The functional unit was 1 kg pd-AAC, and the system boundaries included pd-AAC at the demolition site, transports, pd-AAC treatment, and secondary production processes. Final products of the recycling process gained environmental credits/rewards for avoiding primary production using system expansion. Providing primary resources, primary production, and use phase were not in the scope of this study. Results show that especially closed-loop recycling of pd-AAC in AAC production has a high potential of improving environmental impacts. In the best recycling option (high substitution in AAC-0.35), potential savings per kg pd-AAC compared to landfilling reach up to 0.5 kg CO2-Eq, 7 MJ fossil resources, 0.005 mol H+-Eq (acidification), 0.17 CTU (freshwater ecotoxicity), 0.2 g P-Eq (freshwater eutrophication), 5.2 × 10-9 CTUh (carcinogenic effects), 4.4 × 10-8 CTUh (non-carcinogenic effects), 2.5 × 10-5 g CFC-11-Eq (ozone layer depletion), and 1.6 g NMVOC-Eq (photochemical ozone creation). Despite data uncertainties, recycling of pd-AAC is advantageous for several recycling options, including the production of AAC, light mortar, lightweight aggregate concrete, and shuttering blocks made from concrete without fine fractions (no-fines concrete). In Germany, up to 280,000 t CO2-Eq could have been saved in 2022 by pd-AAC recycling using different recycling options instead of landfilling.

Broccoli Myrosinase cDNA Expression in Escherichia coli and Saccharomyces cerevisiae.

Myrosinases (EC 3.2.1.147) are enzymes known for the generation of hydrolysis products that have a potential beneficial effect on human health. Their reaction mechanisms are widely studied, in order to improve and optimize secondary metabolite production processes. In this work, kinetic and biochemical properties of the broccoli myrosinase enzyme produced from its cDNA cloned in Escherichia coli and Saccharomyces cerevisiae were investigated. The results revealed that the thermal stability of the enzyme produced in S. cerevisiae was slightly higher (30 to 60 °C) than that of myrosinase produced in E. coli (20 to 50 °C). The effect of pH on the enzymatic activity was similar in both enzymes, with pH 3 being the optimum value under the reaction conditions used. The kinetic behavior of both enzymes was adjusted to the Michaelis–Menten model. The catalytic efficiency was up to 4 times higher in myrosinase produced in S. cerevisiae, compared to myrosinase produced in E. coli. The glycosylations present in the enzyme would be related to the formation of a dimeric quaternary structure and would not play an essential role in enzymatic activity, since both enzymes were biologically active. These results will probably allow the development of strategies for the production of bioactive metabolites of medical interest.

Antarctic Special Protected Area 161 as a Reference to Assess the Effects of Anthropogenic and Natural Impacts on Meiobenthic Assemblages

The Antarctic region is usually considered a pristine area. Nevertheless, regional warming effects and increasing human activities, including the presence of several research stations, are inducing considerable environmental changes that may affect the ecosystem’s functions. Therefore, during the XXXIII Antarctic expedition, we carried out an investigation in Terra Nova bay (Ross Sea), close to the Antarctic Specially Protected Area (ASPA) n.161. In particular, we compared the effects of two different types of impacts on the meiobenthic assemblages: anthropogenic impact (AI), associated with the activity of Mario Zucchelli Research Station (MZS), and natural impact (NI) attributable to a large colony of Adélie penguins (Pygoscelis adeliae) in Adelie Cove. For each impacted site, a respective control site and two sampling depths (20 and 50 m) were selected. Several environmental variables (pH, dissolved oxygen, major and minor ions, heavy metals, organic load, and sediment grain size) were measured and analysed, to allow a comprehensive characterization of the sampling areas. According to the criteria defined by Unites States Environmental Protection Agency (US EPA 2009), heavy metal concentrations did not reveal critical conditions. However, both the MZS (AI20) and penguin colony (NI20) sites showed higher heavy metal concentrations, the former due to human activities related to the Italian research station, with the latter caused by the penguins excrements. Meiobenthic richness and abundance values suggested that the worst ecological condition was consistently related to the Adélie penguins colony. Furthermore, the higher contribution of r-strategists corroborates the hypothesis that the chronic impact of the penguin colonies may have stronger effects on the meiobenthos than the human activities at the MZS. Food is not limited in shallow Antarctic bottoms, and microscale differences in primary and secondary production processes can likely explain the greater spatial heterogeneity, highlighted both by the univariate and multivariate attributes of meiobenthic assemblage (i.e., richness, diversity, abundance, whole structure assemblage, and rare taxa) at the deeper stations. As reported in other geographical regions, the assemblage structure of rare meiobenthic taxa is confirmed to be more susceptible to environmental variations, rather than the whole assemblage structure.

Removal of Copper, Nickel, and Iron from Lead–Tin Composite by Segregation of Intermetallic Silicon Phases

In the reduction stage of the secondary copper production process, copper, nickel, lead, and tin are collected in a “black copper”, while zinc is volatilized and precipitated as ZnO in the flue dust. The slag coming from this reduction stage is low in valuable metals and is disposed. In the conversion stage, lead and tin are oxidized and incorporated in the slag phase; in accordance with the oxygen potential, this “converter slag” also contains higher contents of copper and nickel. This slag is then reduced in two stages. From the first stage, a copper–nickel metal is returned to the converter stage, and in the second stage, a crude PbSn composite with copper contents of around 10% and nickel contents of around 2.5%, as well as a further usable slag, is obtained from the “secondary” slag. Iron is used as a reducing agent, so that the metal obtained can contain iron of up to over 10%, depending on the reduction duration. The motivation of this investigation is to provide a method for the subsequent refining of the raw PbSn composite, with the aim of obtain a saleable PbSn composite as well as returning the copper and nickel contents quantitatively to the main copper route or to sell them as an alloy. Therefore, the present work aims to investigate the refining of the raw PbSn composite by the separation of the copper, nickel, and iron via the segregation of intermetallic phases. For that, a series of experiments were performed on the formation and subsequent segregation of intermetallic phases, by introduction of an additional element to the system. The results indicated sharper separation of PbSn composite and copper, nickel, and iron due to the higher thermodynamic stability of these phases (selectivity).

Variations in Spectral Signals of Heavy Metal Contamination in Mine Soils Controlled by Mineral Assemblages

This paper illustrates a spectroscopic analysis of heavy metal concentration in mine soils with the consideration of mineral assemblages originated by weathering and mineralization processes. The mine soils were classified into two groups based on the mineral composition: silicate clay mineral group (Group A) and silicate–carbonate–skarn–clay mineral group (Group B). Both soil groups are contaminated with Cu, Zn, As, and Pb, while the contamination level was higher for Group A. The two groups exhibit different geochemical behaviors with different heavy metal contamination. The spectral variation associated with heavy metal was highly correlated with absorption features of clay and iron oxide minerals for Group A, and the absorption features of skarn minerals, iron oxides, and clay minerals for Group B. It indicates that the geochemical adsorption of heavy metal elements mainly occurs with clay minerals and iron oxides from weathering, and of skarn minerals, iron oxides, and clay minerals from mineralization. Therefore, soils from different secondary mineral production processes should be analyzed with different spectral models. We constructed spectral models for predicting Cu, Zn, As, and Pb in soil group A and Zn and Pb in soil group B using corresponding absorptions. Both models were statistically significant with sufficient accuracy.

Food safety practices in catering during the coronavirus COVID-19 pandemic

On January 30, 2020, the Director-General of the World Health Organization declared the outbreak of COVID-19 a Public Health Emergency of International Concern. There is hardly a country in the world that is not currently facing this problem. The number of cases is constantly growing, patients and carriers being the main mode of transmission. The economies of all countries are at stake. However, people need essential goods and food, regardless of the situation. In this respect, agriculture, food industry, food market, and catering have become priority industries. A continuous operation of food service enterprises (FSE) is crucial for the uninterrupted food supply in the period of preventive measures. The paper describes how pathogen makes its way into FSEs, spreads, and infects people. This information makes it possible to assess the probability of coronavirus infection and to reduce its spread, thus ensuring the safe operation of the enterprise. There are three transmission routes the coronavirus can take at a FSE: (1) aerial transmission by droplets and aerosols during the main and secondary technological production processes, (2) person-to-person transmission from clients to staff or from employee to employee via direct or indirect contact, (3) transmission via contaminated surfaces, e.g. packaging, furniture, equipment, etc. FSEs have to follow the recommendations published by the federal and/or local authorities, which may vary depending on the COVID-19 incidence rate in the area. These recommendations are based on the probability of the public health risk associated with person-to-person transmission, rather than on food safety.

Hourly measurements of organic molecular markers in urban Shanghai, China: Observation of enhanced formation of secondary organic aerosol during particulate matter episodic periods

Abstract Field campaigns rarely measure individual polar organic compounds online, leaving unexplored their potential in tracking the formation dynamics of secondary organic aerosol (SOA). In a three-week-long field campaign in urban Shanghai, we deployed a commercial Thermal desorption Aerosol Gas chromatograph system (TAG) that integrates sampling, in-situ derivatization, and thermal desorption gas chromatography-mass spectrometric analysis, producing hourly measurement of polar organics including a set of biogenic and anthropogenic SOA tracers. The abundance and variations of these SOA tracers were examined in relation to five PM2.5 episodes, varying from 4 to 64 h in duration, during the field campaign from 9 November to 3 December 2018. The episodes were associated with stagnant air parcels. In comparison with the non-episodic hours, the episodic hours showed distinct chemical characteristics of a large mass increment of nitrate (an average of 4.7 fold) and secondary organic compounds (~3–6.4 fold), exceeding those of primary pollutants (1.6–1.9 fold). These results clearly indicate the significant contributions of secondary inorganic and organic production processes to forming PM2.5 episodes. The SOA concentration estimated by the set of TAG-measured SOA tracers reached an average concentration of 2.6 μg/m3, accounting for a significant portion of OA in view of that the total organic matter (OM) in PM1 measured by an Aerosol Mass Spectrometer was 7.9 μg/m3. Among them the SOA attributed to monoaromatic compounds (e.g., toluene) accounted for a noticeable portion of the total OM, implying that control strategies targeting local anthropogenic emissions would be effective in reducing the severity of episodic PM pollution. Examining the ratio of two monoterpene-derived SOA products, we found evidence of less-aged SOA in urban Shanghai, and this result was collaborated by the O/C value (0.4) of bulk OA. This work demonstrates hourly SOA tracer measurements by TAG are uniquely specific on identification of major SOA precursors for episodic events and observing the evolution of SOA.

Abiotic and Biological Degradation of Atmospheric Proteinaceous Matter Can Contribute Significantly to Dissolved Amino Acids in Wet Deposition.

Atmospheric proteinaceous matter is characterized by ubiquity and potential bioavailability. However, little is known about the origins, secondary production processes, and biogeochemical role of proteinaceous matter in wet deposition. Precipitation samples were collected in suburban Guiyang (southwestern China) over a 1 year period to investigate their chemical components, mainly including dissolved combined amino acids (DCAAs), dissolved free AAs (DFAAs), and nonleachable particulate AAs (PAAs). Glycine was most abundant in the DFAAs, while the dominant species in DCAAs and PAAs was glutamic acid (including deaminated glutamine). The total DCAA, DFAA, and PAA concentrations peaked on average in spring (min. in summer). On average, the contribution of DCAA-nitrogen (median of 3.44%) to dissolved organic nitrogen was 5-fold higher than that of DFAA-nitrogen (median of 0.60%). Correlation analyses of AAs with ozone, nitrogen dioxide, and the quantitative degradation index suggest that DC(/F)AAs are linked with both abiotic and biological degradation of proteinaceous matter. Moreover, the high FAA scavenging ratios indicate the presence of postdepositional degradation of atmospheric proteinaceous matter. Further, the positive matrix factorization results suggest that the degradation of atmospheric proteinaceous matter markedly contributes to DCAAs and DFAAs in precipitation. Overall, the results suggest that the secondary processes involved in the degradation of atmospheric proteinaceous matter significantly promote direct bioavailability of AA-nitrogen.

Use of plant hormones to activate silent polyketide biosynthetic pathways in Arthrinium sacchari, a fungus isolated from a spider.

Plant hormones were evaluated for their ability to activate fungal secondary metabolite production. Three synthetic cytokinins, kinetin, 6-benzylaminopurine, and forchlorfenuron, showed remarkable enhancement of the production of aromatic polyketides derived from emodin in a fungus, Arthrinium sacchari, and allowed us to isolate a new polyketide. Furthermore, we firstly demonstrated the potential of plant hormones to activate a wide range of fungal secondary metabolite production processes.

Numerical Study on the Impact of Power Plants on Primary PM10 Concentrations in South Korea

To develop effective emission abatement strategies for eighteen coal-fired power plants located throughout Korea, power plant emission data and TAPM(The Air Pollution Model) were used to quantify the impact of emission reductions on primary PM10 concentrations. TAPM was validated for two separate time periods: a high PM10 concentration period from April 7 to 12, 2016, and a low PM10 concentration period from June 1 to June 6 2016. The validated model was then used to analyze the impacts of five applicable power plant shut-down scenarios. The results showed that shut-down of four power plants located within the Seoul metropolitan area (SMA) would result in up to 18.9% reduction in maximum PM10 concentrations, depending on synoptic conditions. A scenario for the shutdown of a single low stack height with highest-emission power plant located nearest to Seoul showed a small impact on averaged PM10 concentrations (~1%) and 4.4% (0.54 μg/m3) decrease in maximum concentration. The scenario for four shutdowns for power plants aged more than 30 years within SMA also showed a highest improvement of 6.4% (0.26 μg/m3 in April) in averaged PM10 concentrations, and of 18.9% (2.33 μg/m3 in June) in maximum concentration, showing almost linear relationship in and around SMA. Reducing gaseous air pollutant emissions was also found to be significant in controlling high PM10 concentrations, indicating the effectiveness of coreduction of power plant emissions together with diesel vehicle emissions in the SMA. In addition, this study is implying that secondary production process generating PM10 pollution may be a significant process throughout most regions in Korea, and therefore concurrent abatement of both gas and particle emissions will result in more pronounced improvements in air quality over the urban cities in South Korea.

Emission or atmospheric processes? An attempt to attribute the source of large bias of aerosols in eastern China simulated by global climate models

Abstract. Global climate models often underestimate aerosol loadings in China, and these biases can have significant implications for anthropogenic aerosol radiative forcing and climate effects. The biases may be caused by either the emission inventory or the treatment of aerosol processes in the models, or both, but so far no consensus has been reached. In this study, a relatively new emission inventory based on energy statistics and technology, Multi-resolution Emission Inventory for China (MEIC), is used to drive the Community Atmosphere Model version 5 (CAM5) to evaluate aerosol distribution and radiative effects against observations in China. The model results are compared with the model simulations with the widely used Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) emission inventory. We find that the new MEIC emission improves the aerosol optical depth (AOD) simulations in eastern China and explains 22–28 % of the AOD low bias simulated with the AR5 emission. However, AOD is still biased low in eastern China. Seasonal variation of the MEIC emission leads to a better agreement with the observed seasonal variation of primary aerosols than the AR5 emission, but the concentrations are still underestimated. This implies that the atmospheric loadings of primary aerosols are closely related to the emission, which may still be underestimated over eastern China. In contrast, the seasonal variations of secondary aerosols depend more on aerosol processes (e.g., gas- and aqueous-phase production from precursor gases) that are associated with meteorological conditions and to a lesser extent on the emission. It indicates that the emissions of precursor gases for the secondary aerosols alone cannot explain the low bias in the model. Aerosol secondary production processes in CAM5 should also be revisited. The simulation using MEIC estimates the annual-average aerosol direct radiative effects (ADREs) at the top of the atmosphere (TOA), at the surface, and in the atmosphere to be −5.02, −18.47, and 13.45 W m−2, respectively, over eastern China, which are enhanced by −0.91, −3.48, and 2.57 W m−2 compared with the AR5 emission. The differences of ADREs by using MEIC and AR5 emissions are larger than the decadal changes of the modeled ADREs, indicating the uncertainty of the emission inventories. This study highlights the importance of improving both the emission and aerosol secondary production processes in modeling the atmospheric aerosols and their radiative effects. Yet, if the estimations of MEIC emissions in trace gases do not suffer similar biases to those in the AOD, our findings will help affirm a fundamental error in the conversion from precursor gases to secondary aerosols as hinted in other recent studies following different approaches.

Electron transfer ferredoxins with unusual cluster binding motifs support secondary metabolism in many bacteria.

The proteins responsible for controlling electron transfer in bacterial secondary metabolism are not always known or characterised. Here we demonstrate that many bacteria contain a set of unfamiliar ferredoxin encoding genes which are associated with those of cytochrome P450 (CYP) monooxygenases and as such are involved in anabolic and catabolic metabolism. The model organism Mycobacterium marinum M contains eleven of these genes which encode [3Fe-4S] or [4Fe-4S] single cluster containing ferredoxins but which have unusual iron-sulfur cluster binding motif sequences, CXX?XXC(X) n CP, where '?' indicates a variable amino acid residue. Rather than a cysteine residue, which is highly conserved in [4Fe-4S] clusters, or alanine or glycine residues, which are common in [3Fe-4S] ferredoxins, these genes encode at this position histidine, asparagine, tyrosine, serine, threonine or phenylalanine. We have purified, characterised and reconstituted the activity of several of these CYP/electron transfer partner systems and show that all those examined contain a [3Fe-4S] cluster. Furthermore, the ferredoxin used and the identity of the variable motif residue in these proteins affects the functionality of the monooxygenase system and has a significant influence on the redox properties of the ferredoxins. Similar ferredoxin encoding genes were identified across Mycobacterium species, including in the pathogenic M. tuberculosis and M. ulcerans, as well as in a wide range of other bacteria such as Rhodococcus and Streptomyces. In the majority of instances these are associated with CYP genes. These ferredoxin systems are important in controlling electron transfer across bacterial secondary metabolite production processes which include antibiotic and pigment formation among others.

High potential for temperate viruses to drive carbon cycling in chemoautotrophy-dominated shallow-water hydrothermal vents.

Viruses are the most abundant life forms in the world's oceans and they are key drivers of biogeochemical cycles, but their impact on the microbial assemblages inhabiting hydrothermal vent ecosystems is still largely unknown. Here, we analysed the viral life strategies and virus-host interactions in the sediments of a newly discovered shallow-water hydrothermal field of the Mediterranean Sea. Our study reveals that temperate viruses, once experimentally induced to replicate, can cause large mortality of vent microbes, significantly reducing the chemoautotrophic carbon production, while enhancing the metabolism of microbial heterotrophs and the re-cycling of the organic matter. These results provide new insights on the factors controlling primary and secondary production processes in hydrothermal vents, suggesting that the inducible provirus-host interactions occurring in these systems can profoundly influence the functioning of the microbial food web and the efficiency in the energy transfer to the higher trophic levels.

Artificial Neural Network Model for Alkali-Surfactant-Polymer Flooding in Viscous Oil Reservoirs: Generation and Application

Chemical flooding has been widely utilized to recover a large portion of the oil remaining in light and viscous oil reservoirs after the primary and secondary production processes. As core-flood tests and reservoir simulations take time to accurately estimate the recovery performances as well as analyzing the feasibility of an injection project, it is necessary to find a powerful tool to quickly predict the results with a level of acceptable accuracy. An approach involving the use of an artificial neural network to generate a representative model for estimating the alkali-surfactant-polymer flooding performance and evaluating the economic feasibility of viscous oil reservoirs from simulation is proposed in this study. A typical chemical flooding project was referenced for this numerical study. A number of simulations have been made for training on the basis of a base case from the design of 13 parameters. After training, the network scheme generated from a ratio data set of 50%-20%-30% corresponding to the number of samples used for training-validation-testing was selected for estimation with the total coefficient of determination of 0.986 and a root mean square error of 1.63%. In terms of model application, the chemical concentration and injection strategy were optimized to maximize the net present value (NPV) of the project at a specific oil price from the just created ANN model. To evaluate the feasibility of the project comprehensively in terms of market variations, a range of oil prices from 30 $/bbl to 60 $/bbl referenced from a real market situation was considered in conjunction with its probability following a statistical distribution on the NPV computation. Feasibility analysis of the optimal chemical injection scheme revealed a variation of profit from 0.42 $MM to 1.0 $MM, corresponding to the changes in oil price. In particular, at the highest possible oil prices, the project can earn approximately 0.61 $MM to 0.87 $MM for a quarter five-spot scale. Basically, the ANN model generated by this work can be flexibly applied in different economic conditions and extended to a larger reservoir scale for similar chemical flooding projects that demand a quick prediction rather than a simulation process.

Resource recovery from residual household waste: An application of exergy flow analysis and exergetic life cycle assessment

Exergy is based on the Second Law of thermodynamics and can be used to express physical and chemical potential and provides a unified measure for resource accounting. In this study, exergy analysis was applied to four residual household waste management scenarios with focus on the achieved resource recovery efficiencies. The calculated exergy efficiencies were used to compare the scenarios and to evaluate the applicability of exergy-based measures for expressing resource quality and for optimizing resource recovery. Exergy efficiencies were determined based on two approaches: (i) exergy flow analysis of the waste treatment system under investigation and (ii) exergetic life cycle assessment (LCA) using the Cumulative Exergy Extraction from the Natural Environment (CEENE) as a method for resource accounting. Scenario efficiencies of around 17–27% were found based on the exergy flow analysis (higher efficiencies were associated with high levels of material recycling), while the scenario efficiencies based on the exergetic LCA lay in a narrow range around 14%. Metal recovery was beneficial in both types of analyses, but had more influence on the overall efficiency in the exergetic LCA approach, as avoided burdens associated with primary metal production were much more important than the exergy content of the recovered metals. On the other hand, plastic recovery was highly beneficial in the exergy flow analysis, but rather insignificant in exergetic LCA. The two approaches thereby offered different quantitative results as well as conclusions regarding material recovery. With respect to resource quality, the main challenge for the exergy flow analysis is the use of exergy content and exergy losses as a proxy for resource quality and resource losses, as exergy content is not per se correlated with the functionality of a material. In addition, the definition of appropriate waste system boundaries is critical for the exergy efficiencies derived from the flow analysis, as it is constrained by limited information available about the composition of flows in the system as well as about secondary production processes and their interaction with primary or traditional production chains. In the exergetic LCA, resource quality could be reflected by the savings achieved by product substitution and the consideration of the waste’s upstream burden allowed for an evaluation of the waste’s resource potential. For a comprehensive assessment of resource efficiency in waste LCA, the sensitivity of accounting for product substitution should be carefully analyzed and cumulative exergy consumption measures should be complimented by other impact categories.

The Silversmith's Workshop of Tira Del Lienzo (Totana, Murcia) In The Context of Iberian Bronze Age Metallurgy

The south‐east of the Iberian Peninsula saw deep social and political changes at the dawn of the second millennium bce. The emergence of important economic asymmetries inside communities was apparently based to a large extent on control of the secondary metallurgical production process; namely, forging. In this sense, the recently excavated architectural complex at the Argaric site of Tira del Lienzo constitutes an exceptional finding. At this site a series of macrolithic artefacts were recorded, which were related to the forging of metals and, more specifically, to the working of silver, according to morpho‐technological and functional studies (use‐wear and residue analysis).

Trophic Dynamics of Deep-Sea Megabenthos Are Mediated by Surface Productivity

Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ13C and δ15N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation.

Absorption of Λ(1520) hyperons in photon-nucleus collisions

In the framework of the nuclear spectral function approach for incoherent primary photon-nucleon and secondary pion-nucleon production processes we study the inclusive Λ(1520)-hyperon production in the interaction of 2-GeV photons with nuclei. In particular, the A and momentum dependences of the absolute and relative Λ(1520)-hyperon yields are investigated in two scenarios for its in-medium width. Our model calculations show that the pion-nucleon production channel contributes appreciably to the Λ(1520) creation at intermediate momenta both in light and heavy nuclei in the chosen kinematics and, hence, has to be taken into consideration on close examination of the dependences of the Λ(1520)-hyperon yields on the target mass number with the aim to get information on its width in the medium. They also demonstrate that the A and momentum dependences of the absolute and relative Λ(1520)-hyperon production cross sections at incident energy of interest are markedly sensitive to the Λ(1520) in-medium width, which means that these observables may be an important tool to determine the above width.