•Sabatier-based CO2 methanation plant modelling and simulation.•Plant optimization through Pinch Analysis.•Sabatier conversion yield improvement.•Thermoeconomic analysis and identification of ...critical plant components.•Sensitivity analysis of electricity cost, CO2 emission trades and CO2 sequestration costs on methane cost.
The present global energy scenario has to face the technical and economic challenges of the global CO2 emissions mitigation. The two main technological paths followed are on one hand the increase of renewable share and on the other the implementation of carbon capturing and storage solutions. While the main drawback of the first one is the need to include an energy storage to compensate for the fluctuations of the sources, the one of the latter is related to the high CO2 sequestration costs. Sabatier based power-to-gas systems are potential answers for both the above described issues. Object of this paper is the modelling, process design and simulation of a CO2 methanation plant based on the Sabatier reaction. Since the main issue of power-to-methane storage technology is its low overall conversion efficiency, the pinch analysis approach has been applied to enhance the energy recovery that represents a key factor in the increase of the plant global efficiency. An exergy and thermoeconomic analysis of the proposed plant was performed in order to evaluate the main sources of irreversibility and to calculate the CH4 production costs as a function of the main plant parameters. A Sabatier conversion yield of 93.48% has been obtained producing 0.42 kg of CH4 per each kg of captured CO2 with an improved cost of 53 €/MWh. The results of the study have shown the great potentials of this solution as an “energy storage” and CO2 capture facility.
Optimization of the operating conditions of district heating networks is usually performed limiting the analysis to the primary energy related with heat production. An additional aspect that should ...be considered is the role played by the pumping system. Pumping may contribute to about 10% of the total primary energy consumption, especially in large networks or when small temperature levels are applied. Furthermore, the increasing share of waste heat or renewable energy sources from distributed producers requires a flexible and efficient pumping system. A further aspect which pumping strategy should face is system operation when malfunctions in the plants, pumps or pipes occur.
Optimization of the pumping system requires the use of detailed simulation tools, which may need significant computational resources, especially in the case of large networks. A reduced model, based on Proper Orthogonal Decomposition combined with Radial basis functions (POD-RBF model) is proposed in this paper. This approach allows maintaining high level of accuracy despite reductions of more than 80% in the computational time. This make the approach effective tool for control strategy operations. An application to a large district heating network shows that reductions of about 20% in the pumping request and effective management of failures are possible.
Display omitted
•A reduced fluid dynamic model of District Heating Networks based on POD-RBF is proposed.•The reduced model is successfully applied to pumping cost minimization.•The best pumping settings are obtained for normal and malfunctioning operation.•The optimal strategy allows 20% reduction in the pumping power with respect to the current strategy.
Human organoids could facilitate research of complex and currently incurable neuropathologies, such as age-related macular degeneration (AMD) which causes blindness. Here, we establish a human ...retinal organoid system reproducing several parameters of the human retina, including some within the macula, to model a complex combination of photoreceptor and glial pathologies. We show that combined application of TNF and HBEGF, factors associated with neuropathologies, is sufficient to induce photoreceptor degeneration, glial pathologies, dyslamination, and scar formation: These develop simultaneously and progressively as one complex phenotype. Histologic, transcriptome, live-imaging, and mechanistic studies reveal a previously unknown pathomechanism: Photoreceptor neurodegeneration via cell extrusion. This could be relevant for aging, AMD, and some inherited diseases. Pharmacological inhibitors of the mechanosensor PIEZO1, MAPK, and actomyosin each avert pathogenesis; a PIEZO1 activator induces photoreceptor extrusion. Our model offers mechanistic insights, hypotheses for neuropathologies, and it could be used to develop therapies to prevent vision loss or to regenerate the retina in patients suffering from AMD and other diseases.
Petroleum products account for the 32.3% of worldwide primary energy. There are more than 100 oil refineries in Europe that directly employ 119,000 people with a turnover of EUR 600 billion and ...around 1.2% to the total value added in manufacturing. Therefore, the petroleum refining sector is very important in the European economy, and its decarbonization is crucial in the energy transition. Refineries present a high degree of complexity and integration, and the continuous increase of their energy efficiency is a key topic for the sector. In this work an analysis of the energy efficiency in ten Italian refineries based on mandatory energy audits and public data is presented. The primary (0.0963 ± 0.0341 toe/t), thermal (3421.71 ± 1316.84 MJ/t), and electrical (68.20 ± 19.34 kWh/t) specific energy consumptions have been evaluated. Some insights about the impact of refined products mix (mainly driven by production of diesel fuel) and Nelson Complexity Index in energy consumption are presented. Lastly, an overview of energy performance improvement actions (EPIAs) information extracted from energy audits is presented. This work presents a first step for the benchmark of Italian refineries that should be subsequently improved.
The objective of this work is the energy characterisation and evaluation of the energy efficiency potential of the rubber manufacturing industry in Italy, exploiting the detailed data included in ...energy audits by large and energy-intensive companies. This sector is divided into two sub-activities: the manufacture of rubber products and the production of tyres. Existing studies are focused mainly on tyre production, and there is a lack of quantitative evaluation of energy indicators that can provide guidance for improving process efficiency. In this work, updated global and specific energy performance indicators (EnPIs) related to the production process and to the auxiliary and general services are defined and evaluated. At the same time, targeted actions and interventions to improve the energy efficiency of the sector are analysed, showing the role of different intervention areas and their cost-effectiveness. The analysis is based on 100 Italian mandatory energy audits of the sector collected according to Art.8 EU Directive 27/2012. The applied methodology made it possible to calculate specific energy performance indicators by considering the overall and sub-process energy consumption of different production sites. Based on a detailed database containing real data from recent energy audits, this study provides an up-to-date and reliable benchmark for the rubber industry sector. In addition, the analysis of energy audits allows the identification of the most effective energy efficiency interventions for the rubber industry in terms of cost-effectiveness and payback time.
Childhood and adolescence are the life stages where eating habits related to the development of cardiovascular risk factors are usually established.BACKGROUNDChildhood and adolescence are the life ...stages where eating habits related to the development of cardiovascular risk factors are usually established.To classify cardiovascular risk in school adolescents from Villavicencio (Colombia) and, additionally, to estimate its association with food intake frequency according to food kind.OBJECTIVETo classify cardiovascular risk in school adolescents from Villavicencio (Colombia) and, additionally, to estimate its association with food intake frequency according to food kind.This is an analytical cross-sectional study developed in 1,504 adolescents of 13 to 17 years of age schooling in Villavicencio. We evaluated the cardiovascular risk according to the model proposed by Rodríguez-Soriano and Sanjurjo, and the food intake frequency with a structured survey. We used a binomial regression model to estimate the relationship between cardiovascular risk and food intake frequency.METHODOLOGYThis is an analytical cross-sectional study developed in 1,504 adolescents of 13 to 17 years of age schooling in Villavicencio. We evaluated the cardiovascular risk according to the model proposed by Rodríguez-Soriano and Sanjurjo, and the food intake frequency with a structured survey. We used a binomial regression model to estimate the relationship between cardiovascular risk and food intake frequency.The mean age of the participants was 14.9 ± 0,07 years; 61.9% were women, and 80.6% came from schools located in urban areas. According to the cardiovascular risk classification, 34.5% of adolescents had a high cardiovascular risk, while 25.4% had intermediate risk. Men and those who consume more than two sugary drinks per day are those who presented a higher percentage of high cardiovascular risk (48.6% and 36.9%, respectively). Regression models showed that consumption of more than one sugary drink per day was associated with high levels of cardiovascular risk in adolescents (OR 1.27 95%CI 1.04-1.55).RESULTSThe mean age of the participants was 14.9 ± 0,07 years; 61.9% were women, and 80.6% came from schools located in urban areas. According to the cardiovascular risk classification, 34.5% of adolescents had a high cardiovascular risk, while 25.4% had intermediate risk. Men and those who consume more than two sugary drinks per day are those who presented a higher percentage of high cardiovascular risk (48.6% and 36.9%, respectively). Regression models showed that consumption of more than one sugary drink per day was associated with high levels of cardiovascular risk in adolescents (OR 1.27 95%CI 1.04-1.55).A high proportion of adolescents have medium and high cardiovascular risk; additionally, the consumption ofsugary drinks showed its association with cardiovascular risk.CONCLUSIONA high proportion of adolescents have medium and high cardiovascular risk; additionally, the consumption ofsugary drinks showed its association with cardiovascular risk.
In this work, a novel methodology to assess energy performance indicators of productive and economic sectors trough the analysis of the Italian mandatory energy audits database is presented. The ...updating of sectoral reference energy performance indicators is fundamental for both companies and policy makers—for the formers to evaluate and compare their energy performance with competitors in order to achieve improvements and for the latter to effectively monitor the impact of energy policies. This methodology could be potentially applied to all production sectors, providing key information needed to characterize various production processes from an energy point of view. Awareness of energy efficiency and sectorial benchmarking represent the first necessary steps for companies moving towards energy transition. This paper provides details of the statistical method developed and its application to the NACE 23 division “Manufacturing of other non-metallic mineral products”, with a focus on the cement industry. For this sector, results are presented in terms of specific indicators based on energy source. General results, methodological insights, and validation of the proposed case study are discussed.
Objective To determine whether very low birth weight infants (VLBWIs), initially supported with continuous positive airway pressure (CPAP) and then selectively treated with the INSURE (intubation, ...surfactant, and extubation to CPAP; CPAP/INSURE) protocol, need less mechanical ventilation than those supported with supplemental oxygen, surfactant, and mechanical ventilation if required (Oxygen/mechanical ventilation MV). Study design In a multicenter randomized controlled trial, spontaneously breathing VLBWIs weighing 800-1500 g were allocated to receive either therapy. In the CPAP/INSURE group, if respiratory distress syndrome (RDS) did not occur, CPAP was discontinued after 3-6 hours. If RDS developed and the fraction of inspired oxygen (FiO2 ) was >0.35, the INSURE protocol was indicated. Failure criteria included FiO2 >0.60, severe apnea or respiratory acidosis, and receipt of more than 2 doses of surfactant. In the Oxygen/MV group, in the presence of RDS, supplemental oxygen without CPAP was given, and if FiO2 was >0.35, surfactant and mechanical ventilation were provided. Results A total of 256 patients were randomized to either the CPAP/INSURE group (n = 131) or the Oxygen/MV group (n = 125). The need for mechanical ventilation was lower in the CPAP/INSURE group (29.8% vs 50.4%; P = .001), as was the use of surfactant (27.5% vs 46.4%; P = .002). There were no differences in death, pneumothorax, bronchopulmonary dysplasia, and other complications of prematurity between the 2 groups. Conclusion CPAP and early selective INSURE reduced the need for mechanical ventilation and surfactant in VLBWIs without increasing morbidity and death. These results may be particularly relevant for resource-limited regions.
Pediatric cancer survivors are at increased risk of cardiac dysfunction and heart failure. Reduced peak oxygen consumption (peak VO
) is associated with impaired cardiac reserve (defined as the ...increase in cardiac function from rest to peak exercise) and heart failure risk, but it is unclear whether this relationship exists in pediatric cancer survivors. This study sought to investigate the presence of reduced peak VO
in pediatric cancer survivors with increased risk of heart failure, and to assess its relationship with resting cardiac function and cardiac haemodynamics and systolic function during exercise.
Twenty pediatric cancer survivors (8-24 years; 10 male) treated with anthracycline chemotherapy ± radiation underwent cardiopulmonary exercise testing to quantify peak VO
, with a value < 85% of predicted defined as impaired peak VO
. Resting cardiac function was assessed using 2- and 3-dimensional echocardiography, with cardiac reserve quantified from resting and peak exercise heart rate, stroke volume index (SVI) and cardiac index (CI) using exercise cardiovascular magnetic resonance (CMR).
Twelve of 20 survivors (60%) had reduced peak VO
(70 ± 16% vs. 97 ± 14% of age and gender predicted). There were no differences in echocardiographic or CMR measurements of resting cardiac function between survivors with normal or impaired peak VO
. However, those with reduced peak VO
had diminished cardiac reserve, with a lesser increase in CI and SVI during exercise (Interaction P < 0.01 for both), whilst the heart rate response was similar (P = 0.71).
Whilst exercise intolerance is common among pediatric cancer survivors, it is poorly explained by resting measures of cardiac function. In contrast, impaired exercise capacity is associated with impaired haemodynamics and systolic functional reserve measured during exercise. Consequently, measures of cardiopulmonary fitness and cardiac reserve may aid in early identification of survivors with heightened risk of long-term heart failure.
Nucleic acids have clear clinical potential for gene therapy. Plasmid DNA (pDNA) was the first nucleic acid to be pursued as a therapeutic molecule. Recently, mRNA came into play as it offers ...improved safety and affordability. In this study, we investigated the uptake mechanisms and efficiencies of genetic material by cells. We focused on three main variables (1) the nucleic acid (pDNA, or chemically modified mRNA), (2) the delivery vector (Lipofectamine 3000 or 3DFect), and (3) human primary cells (mesenchymal stem cells, dermal fibroblasts, and osteoblasts). In addition, transfections were studied in a 3D environment using electrospun scaffolds. Cellular internalization and intracellular trafficking were assessed by using enhancers or inhibitors of endocytosis and endosomal escape. The polymeric vector TransIT-X2 was included for comparison purposes. While lipoplexes utilized several entry routes, uptake via caveolae served as the main route for gene delivery. pDNA yielded higher expression levels in fast-dividing fibroblasts, whereas, in slow-dividing osteoblasts, cmRNA was responsible for high protein production. In the case of mesenchymal stem cells, which presented an intermediate doubling time, the combination vector/nucleic acid seemed more relevant than the nucleic acid per se. In all cases, protein expression was higher when the cells were seeded on 3D scaffolds.
Display omitted
Balmayor and colleagues demonstrate that cellular uptake via caveolae-mediated endocytosis is the most productive route for delivery of mRNA and pDNA complexes. In slow-dividing cells, cmRNA yielded higher levels of expression compared with pDNA. This study provides insights into the choice of nucleic acid used in gene delivery for different cell types and culture scenarios.
PDF
