Potential performance of environmental friendly application of ORC and Flash technology in geothermal power plants

The successful exploitation of geothermal energy for power production relies on to the availability of nearly zero emission and efficient technologies, able to provide flexible operation. It can be realized with the binary cycle technology. It consists of a closed power cycle coupled to a closed geothermal loop, whereby the closed power cycle is generally accomplished by means of an organic Rankine cycle (in a few cases the Kalina cycle has been adopted). The confinement of the geothermal fluid in a closed loop is an important advantage from the environmental point of view: possible pollutants contained in the geothermal fluid are not released into the ambient and are directly reinjected underground. Although a well-established technology in the frame of geothermal applications, the adoption of the binary cycle technology is at the moment typically confined to the exploitation of medium-low temperature liquid geothermal reservoirs, generally between 100-170°C. The important advantages of the binary cycle technology from the environmental point of view suggest nevertheless that it is worthwhile to investigate whether the application range could be extended to higher temperature reservoirs, and up to which extent. Moreover, the paper investigates the effect of an increasing CO2content in the geothermal fluid. The paper compares in a convenient high temperature range of the geothermal source the performance of a properly optimized geothermal ORC plant, with the performance of a modified flash plant, whereby the geothermal steam enters a turbine, and the CO2stream is separated, compressed and finally reinjected. An environmentally friendly working fluid, recently introduced in the market, is considered in the ORC optimization process. The performance comparison will involve the assessment of plant net power. As far as the calculations are concerned, the geothermal fluid is assumed to be a mixture of water and possibly CO2. The auxiliary power consumption is properly accounted for: beyond cooling auxiliaries, a submersible well pump for the ORC plant and a gas compressor for the reinjection of the non-condensable gases in the flash plant are considered

Zero Emission Geothermal Flash Power Plant

The successful exploitation of geothermal energy for power production relies on the availability of nearly zero emission and efficient technologies. Two zero emission flash plant layouts, with full reinjection of the geothermal fluid (non-condensable gas included), are considered. This paper focusses on the CO2issue, and therefore only the carbon dioxide is considered as non-condensable gas present in the geothermal fluid; the CO2 flow is separated, compressed, and reinjected with the geothermal fluid. Both the reservoir and the power plant are simulated. A first scheme of plant presents a conventional layout in which the CO2is separated and compressed after the condenser. The second scheme presents a plant layout that allows the separation of the CO2at higher pressure with respect to the conventional layout, thus reducing the requested power consumption. The conventional plant scheme performs always better at higher temperature and at lower concentration of CO2. The new layout results better for low temperature and higher gas content

Comparison of Enhanced Organic Rankine Cycles for Geothermal Power Units

Binary cycles have drawn the attention as a technical solution for the geothermal power production. This attention is mainly due to the huge potential of medium-low temperature geothermal sources, typically exploited by means of a binary cycle, and the relevance of the environmental concern, which can be conveniently dealt with by means of a closed cycle. The binary cycle has been therefore the object of an extended research activity, in order to attain higher plant performance. A crucial matter is the improvement of the heat introduction process. For a given geothermal fluid in liquid state, i.e. for a variable temperature heat source, in a conventional ORC the working fluid evaporation process is responsible for an important second law loss: removal of this loss allows greater power and possibly higher cycle efficiency to be attained. Aim of the present paper is to investigate and compare recently proposed technical solutions based on the current technology, which do not entail considerable operating risk or relevant investment; they can however lead to an improvement in plant performance and economics. The selected cycle options were dealt with in the open literature, and try to reduce the heat introduction second law loss: in the first one, the so called OFC, this loss is strongly reduced, because heat is introduced in the cycle when the working fluid is in liquid phase, but a dissipative flash process is then required. In the second one, the so called Pinch Point Smoother, this loss is reduced because the working fluid heating curve is smoothed by means of a flow split, which allows a fraction of the working fluid flow to evaporate at a pressure lower than the pressure of the main flow, but mechanical recompression is then required to inject the separated flow fraction into the turbine. The result of comparison may depend both on the temperature level of thermal sources involved and on the working fluid selected: the present paper will discuss several examples, representative of geothermal applications, and try to assess whether the adoption of these solutions can be convenient for geothermal exploitation

Procesos de colectivización de demandas: perspectiva de análisis

La presente ponencia analiza la importancia de los procesos de intervención profesional del trabajo social en los cuales la población usuaria de servicios sociales estatales logra colectivizar demandas en el tenso y contradictorio interjuego entre políticas sociales, instituciones y sujetos colectivos. De esta manera se ponen en tensión interpretaciones políticas que fragmentan e individualizan las expresiones de la cuestión social, para encontrar respuestas más abarcadoras y colectivizadoras.Mesa de trabajo 15: Territorios Eje temático 3: Procesos de producción y reproducción socialFacultad de Trabajo Socia

Microbiota-driven gut vascular barrier disruption is a prerequisite for non-alcoholic steatohepatitis development.

BACKGROUND & AIMS Fatty liver disease, including non-alcoholic fatty liver (NAFLD) and steatohepatitis (NASH), has been associated with increased intestinal barrier permeability and translocation of bacteria or bacterial products into the blood circulation. In this study, we aimed to unravel the role of both intestinal barrier integrity and microbiota in NAFLD/NASH development. METHODS C57BL/6J mice were fed with high-fat diet (HFD) or methionine-choline-deficient diet for 1 week or longer to recapitulate aspects of NASH (steatosis, inflammation, insulin resistance). Genetic and pharmacological strategies were then used to modulate intestinal barrier integrity. RESULTS We show that disruption of the intestinal epithelial barrier and gut vascular barrier (GVB) are early events in NASH pathogenesis. Mice fed HFD for only 1 week undergo a diet-induced dysbiosis that drives GVB damage and bacterial translocation into the liver. Fecal microbiota transplantation from HFD-fed mice into specific pathogen-free recipients induces GVB damage and epididymal adipose tissue enlargement. GVB disruption depends on interference with the WNT/β-catenin signaling pathway, as shown by genetic intervention driving β-catenin activation only in endothelial cells, preventing GVB disruption and NASH development. The bile acid analogue and farnesoid X receptor agonist obeticholic acid (OCA) drives β-catenin activation in endothelial cells. Accordingly, pharmacologic intervention with OCA protects against GVB disruption, both as a preventive and therapeutic agent. Importantly, we found upregulation of the GVB leakage marker in the colon of patients with NASH. CONCLUSIONS We have identified a new player in NASH development, the GVB, whose damage leads to bacteria or bacterial product translocation into the blood circulation. Treatment aimed at restoring β-catenin activation in endothelial cells, such as administration of OCA, protects against GVB damage and NASH development. LAY SUMMARY The incidence of fatty liver disease is reaching epidemic levels in the USA, with more than 30% of adults having NAFLD (non-alcoholic fatty liver disease), which can progress to more severe non-alcoholic steatohepatitis (NASH). Herein, we show that disruption of the intestinal epithelial barrier and gut vascular barrier are early events in the development of NASH. We show that the drug obeticholic acid protects against barrier disruption and thereby prevents the development of NASH, providing further evidence for its use in the prevention or treatment of NASH

Brain Abnormalities in Individuals with a Desire for a Healthy Limb Amputation: Somatosensory, Motoric or Both? A Task-Based fMRI Verdict

Body integrity dysphoria (BID), a long-lasting desire for the amputation of physically healthy limbs, is associated with reduced fMRI resting-state functional connectivity of somatosensory cortices. Here, we used fMRI to evaluate whether these findings could be replicated and expanded using a task-based paradigm. We measured brain activations during somatosensory stimulation and motor tasks for each of the four limbs in ten individuals with a life-long desire for the amputation of the left leg and fourteen controls. For the left leg, BID individuals had reduced brain activation in the right superior parietal lobule for somatosensory stimulation and in the right paracentral lobule for the motor task, areas where we previously found reduced resting-state functional connectivity. In addition, for somatosensory stimulation only, we found a robust reduction in activation of somatosensory areas SII bilaterally, mostly regardless of the stimulated body part. Areas SII were regions of convergent activations for signals from all four limbs in controls to a significantly greater extent than in subjects with BID. We conclude that BID is associated with altered integration of somatosensory and, to a lesser extent, motor signals, involving limb-specific cortical maps and brain regions where the first integration of body-related signals is achieved through convergence

Sarcopenic Dysphagia, Malnutrition, and Oral Frailty in Elderly: A Comprehensive Review.

Frailty is a highly prevalent condition in the elderly that has been increasingly considered as a crucial public health issue, due to the strict correlation with a higher risk of fragility fractures, hospitalization, and mortality. Among the age-related diseases, sarcopenia and dysphagia are two common pathological conditions in frail older people and could coexist leading to dehydration and malnutrition in these subjects. "Sarcopenic dysphagia" is a complex condition characterized by deglutition impairment due to the loss of mass and strength of swallowing muscles and might be also related to poor oral health status. Moreover, the aging process is strictly related to poor oral health status due to direct impairment of the immune system and wound healing and physical and cognitive impairment might indirectly influence older people's ability to carry out adequate oral hygiene. Therefore, poor oral health might affect nutrient intake, leading to malnutrition and, consequently, to frailty. In this scenario, sarcopenia, dysphagia, and oral health are closely linked sharing common pathophysiological pathways, disabling sequelae, and frailty. Thus, the aim of the present comprehensive review is to describe the correlation among sarcopenic dysphagia, malnutrition, and oral frailty, characterizing their phenotypically overlapping features, to propose a comprehensive and effective management of elderly frail subjects

A Geological Itinerary Through the Southern Apennine Thrust-Belt (Basilicata—Southern Italy)

Open access via Springer Compact AgreementPeer reviewedPublisher PD

On the model flexibility of the geographical distributed real-time co-simulation: The example of ENET-RT lab

The decarbonisation of the energy sector represents a challenge that requires new tools and approaches of analysis. This paper aims to demonstrate the fundamental role that geographical distributed real-time co-simulations (GD-RTDS) can play in this regard. To this end, three different case studies have been analysed with GD-RTDS, covering a wide range of applications for the energy sector decarbonization: a) implementation of Renewable Energy Communities for supporting the share increase of Renewable Energy Sources, b) the integration and management of Onshore Power Supply, and c) the integration of a forecasting tool for the management of the Electric Vehicle charging. The performed experiments included fully simulated components, together with (power) hardware-in-the-loop and software-in-the-loop elements. These components have been simulated in different laboratory facilities in Italy and Germany, all operating in a synchronised manner under the presented geographically-distributed setup. The results show that the proposed architecture is flexible enough to be used for modelling all the different case studies; moreover, they highlight the significant contribution that the GD-RTDS methodology can give in informing and driving energy transition policies and the fundamental role of power systems to spearhead the complete decarbonisation of the energy sector

Childhood-onset dystonia-causing KMT2B variants result in a distinctive genomic hypermethylation profile

Background: Dystonia is a clinically and genetically heterogeneous movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements and/or postures. Heterozygous variants in lysine methyltransferase 2B (KMT2B), encoding a histone H3 methyltransferase, have been associated with a childhood-onset, progressive and complex form of dystonia (dystonia 28, DYT28). Since 2016, more than one hundred rare KMT2B variants have been reported, including frameshift, nonsense, splice site, missense and other in-frame changes, many having an uncertain clinical impact. Results: We characterize the genome-wide peripheral blood DNA methylation profiles of a cohort of 18 patients with pathogenic and unclassified KMT2B variants. We resolve the “episignature” associated with KMT2B haploinsufficiency, proving that this approach is robust in diagnosing clinically unsolved cases, properly classifying them with respect to other partially overlapping dystonic phenotypes, other rare neurodevelopmental disorders and healthy controls. Notably, defective KMT2B function in DYT28 causes a non-random DNA hypermethylation across the genome, selectively involving promoters and other regulatory regions positively controlling gene expression. Conclusions: We demonstrate a distinctive DNA hypermethylation pattern associated with DYT28, provide an epigenetic signature for this disorder enabling accurate diagnosis and reclassification of ambiguous genetic findings and suggest potential therapeutic approaches