Profiled membranes (also known as corrugated membranes, micro-structured membranes, patterned membranes, membranes with designed topography or notched membranes) are gaining increasing academic and ...industrial attention and recognition as a viable alternative to flat membranes. So far, profiled ion exchange membranes have shown to significantly improve the performance of reverse electrodialysis (RED), and particularly, electrodialysis (ED) by eliminating the spacer shadow effect and by inducing hydrodynamic changes, leading to ion transport rate enhancement. The beneficial effects of profiled ion exchange membranes are strongly dependent on the shape of their profiles (corrugations/patterns) as well as on the flow rate and salts' concentration in the feed streams. The enormous degree of freedom to create new profile geometries offers an exciting opportunity to improve even more their performance. Additionally, the advent of new manufacturing methods in the membrane field, such as 3D printing, is anticipated to allow a faster and an easier way to create profiled membranes with different and complex geometries.
This article updates the Heart Failure Association of the European Society of Cardiology (ESC) 2007 classification of advanced heart failure and describes new diagnostic and treatment options for ...these patients. Recognizing the patient with advanced heart failure is critical to facilitate timely referral to advanced heart failure centres. Unplanned visits for heart failure decompensation, malignant arrhythmias, co‐morbidities, and the 2016 ESC guidelines criteria for the diagnosis of heart failure with preserved ejection fraction are included in this updated definition. Standard treatment is, by definition, insufficient in these patients. Inotropic therapy may be used as a bridge strategy, but it is only a palliative measure when used on its own, because of the lack of outcomes data. Major progress has occurred with short‐term mechanical circulatory support devices for immediate management of cardiogenic shock and long‐term mechanical circulatory support for either a bridge to transplantation or as destination therapy. Heart transplantation remains the treatment of choice for patients without contraindications. Some patients will not be candidates for advanced heart failure therapies. For these patients, who are often elderly with multiple co‐morbidities, management of advanced heart failure to reduce symptoms and improve quality of life should be emphasized. Robust evidence from prospective studies is lacking for most therapies for advanced heart failure. There is an urgent need to develop evidence‐based treatment algorithms to prolong life when possible and in accordance with patient preferences, increase life quality, and reduce the burden of hospitalization in this vulnerable patient population.
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•Development of a sustainable process to maximise the potential of Dunaliella salina.•Recovery and fractionation of large diversity of compounds from Dunaliella salina.•Integrated ...approach involving REACH solvents and organic solvent nanofiltration.•Recovery of 94% of polar lipids, 85% of carotenoids and 86% of glycerol.•Economic evaluation provided an appealing ROI of 440% and an IRR of 53%
Dunaliella salina is well-known for its high content in carotenoids and glycerol. Nevertheless, Dunaliella salina has also a high content in lipids, including polar lipids, which are suitable for nutraceutical/cosmeceutical applications. This work proposes a sustainable process to maximise the potential of Dunaliella salina for the production of distinct fractions of carotenoids, glycerol, polar lipids and proteins, which may contribute to improve the revenues of the microalgae industry. In this work, extraction with non-hazardous solvents and organic solvent nanofiltration are integrated, in order to obtain added-value products and glycerol. Also, aiming to separate carotenoids from glycerides, a saponification process is proposed. High overall recoveries were obtained for carotenoids (85%), glycerol (86%), polar lipids (94%) and proteins (95%). In order to evaluate the profitability of the proposed biorefinery, an economic assessment was accomplished. Both CAPEX and OPEX (Capital and Operating expenditure) were calculated, likewise the Return of Investment (ROI).
Reverse electrodialysis (RED) is a sustainable technology for salinity gradient energy harvesting. In order to make the process economically competitive, it is desirable to operate it at the highest ...possible net power density, which depends on the RED stack geometry and on the pressure drop along its pathways and, thus, on the energy spent for solutions pumping. The fluid flow in RED stacks generally occurs in rectangular compartment channels, equipped with spacers. The effects of spacers design and properties have been studied extensively in recent years. However, the other possible causes for a RED stack and their relative impact on the process performance have not yet been systematically studied. In this study the partial pressure drops in (1) distribution ducts, (2) branches, (3) beams, (4) due to sudden section expansion between the beam and the compartment channel and (5) in the compartment channel were taken into consideration. A model for the total pressure drop inside a RED stack, with a parallel fluid flow distribution through the compartments, is proposed and experimentally validated for lab-scale RED stacks with sheet flow spacers and compared with an open channel (spacer-free) design. The importance of each partial pressure drop was then evaluated quantitatively through model simulations for industrial-scale stacks with an increasing number of cell pairs. It was found that the net power density decreases when the cell-pair number increases, since the partial pressure drop in the branches becomes dominant. Moreover, the possible reasons for a non-uniform fluid flow distribution are discussed, thus making the proposed model useful for planning and/or optimization of RED stacks design.
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•A mathematical model for pressure drop simulation inside RED stacks is proposed.•Guidelines for planning and/or optimization of RED stacks are derived.•For large-scale stacks, the partial pressure drop in the branches becomes dominant.•At identical hydrodynamic conditions, net power density depends on cell-pair number.
Power generation by reverse electrodialysis (RED) depends on ionic mass transfer through alternately arranged cation- and anion-exchange membranes. Chronopotentiometric measurements were carried out ...in an EDR-Z Mini stack (MEGA a.s.), equipped with Ralex heterogeneous membranes, separated by either sheet flow spacers or mesh-free gaskets. Various concentrations of model NaCl solutions were used to study the ohmic and non-ohmic resistances in the stack under different hydrodynamic conditions. In order to eliminate the uncertainties associated with a non-uniform distribution of the applied current over the membrane surface, the relaxation zone of the obtained chronopotentiograms was used to estimate the diffusion boundary layer thickness. It was found that this approach provide more accurate data under RED operating conditions, which are strongly influenced by entrance effects on mass transfer, especially for a spacer-free channel configuration. For shorter flow channels, since the salt concentration profile across the diffusion boundary layer is not yet fully developed, more power can be obtained than in the case of longer channels. The presence of spacers was found to reduce the boundary layer thickness, but also increased the ohmic resistance, due to their shadow effect over the membrane surface. The description of the impact of flow entrance effects on mass transfer, and therefore on diffusion boundary layer thickness, can be useful for characterization and further design and/or optimization of RED stacks performance.
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•The diffusion boundary layer (DBL) thickness has been accessed under RED operating conditions.•Diffusion relaxation zone of chronopotentiogram allows for accurate estimation of DBL thickness.•In a RED stack with spacer-free channels, the Leveque equation adjusted well to experimental data.•Flow entrance effects on mass transfer could strongly favor power generation in RED stacks.
Implementation of reverse electrodialysis (RED) is economically limited by the relatively high ion-exchange membranes price. Additionally, the shadow effect of non-conductive spacers reduces the ...membrane area available for counter-ion transport and increases the stack electric resistance. A promising alternative could be utilization of profiled membranes, since the reliefs formed on their surface keeps the membranes separated and provides channels for solutions flow. Herein, we have simulated, through computational fluid dynamics (CFD) tools, fluid behavior in channels formed by various profiled membranes. The highest net power density values were obtained for corrugations shape and arrangement in a form of chevrons due to the increase of the available membrane area and an excellent balance between enhancement of mass transfer and the increase of the pressure drop in the channel. When properly designed, corrugated membranes may offer a better performance even compared to the case of conductive spacers. The proposed membrane corrugation design in not limited to the RED application, and could be also extended to other electromembrane processes, such as electrodialysis and Donnan dialysis, in which high ionic mass transport rates are desirable at as low as possible energy costs.
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•The obtainable net power density in RED has been modeled using CFD tools.•Corrugations perpendicular to the fluid flow are not effective to improve the RED performance.•Chevron structures are found to be the most promising corrugation geometry.•Profiled membranes perform better than conductive spacers.
Aims
To identify differences in clinical epidemiology, in‐hospital management and 1‐year outcomes among patients hospitalized for acute heart failure (AHF) and enrolled in the European Society of ...Cardiology Heart Failure Long‐Term (ESC‐HF‐LT) Registry, stratified by clinical profile at admission.
Methods and results
The ESC‐HF‐LT Registry is a prospective, observational study collecting hospitalization and 1‐year follow‐up data from 6629 AHF patients. Among AHF patients enrolled in the registry, 13.2% presented with pulmonary oedema (PO), 2.9% with cardiogenic shock (CS), 61.1% with decompensated heart failure (DHF), 4.8% with hypertensive heart failure (HT‐HF), 3.5% with right heart failure (RHF) and 14.4% with AHF and associated acute coronary syndromes (ACS‐HF). The 1‐year mortality rate was 28.1% in PO, 54.0% in CS, 27.2% in DHF, 12.8% in HT‐HF, 34.0% in RHF and 20.6% in ACS‐HF patients. When patients were classified by systolic blood pressure (SBP) at initial presentation, 1‐year mortality was 34.8% in patients with SBP <85 mmHg, 29.0% in those with SBP 85–110 mmHg, 21.2% in patients with SBP 110–140 mmHg and 17.4% in those with SBP >140 mmHg. These differences tended to diminish in the months post‐discharge, and 1‐year mortality for the patients who survived at least 6 months post‐discharge did not vary significantly by either clinical profile or SBP classification.
Conclusion
Rates of adverse outcomes in AHF remain high, and substantial differences have been found when patients were stratified by clinical profile or SBP. However, patients who survived at least 6 months post‐discharge represent a more homogeneous group and their 1‐year outcome is less influenced by clinical profile or SBP at admission.
Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes ...contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.
Many separation processes in petrochemical and refining industries are applied to close boiling point compounds and/or azeotropic mixtures which make difficult the application of simple distillation, ...requiring alternative separation processes. Ionic liquids, with their unique and tunable properties, may constitute an advantageous alternative as extractive solvents in separation processes that involve hydrocarbon systems. In this work, a review on the experimental data available for ternary systems composed of ionic liquids and hydrocarbons is reported. The gathered information was shown to be essential in the understanding of the molecular interactions and of the effect of the various structural features of both the ionic liquids and the hydrocarbons on their phase behavior, allowing the development of guidelines for the choice of the most suitable ionic liquid for hydrocarbon separation. To be able to carry out the design and selection of new and improved ionic liquids, the development of predictive models and their validation is required, since the experimental screening of the huge number of potential ionic liquids is not feasible. In this context, the ability of COSMO-RS (COnductor-like Screening MOdel for Real Solvents) as a predictive tool to describe the liquid–liquid equilibria of ternary systems composed of ionic liquids and hydrocarbons, is evaluated. The results obtained with COSMO-RS testify its ability for the qualitative, and in some cases the quantitative, description of the phase behavior of the systems studied.
•Mercury removal from water achieved through the ion exchange membrane bioreactor.•Mercury removal to levels below the 1ppb drinking water limit were achieved.•>98% removal of Hg achieved, with >98% ...biologically reduced from Hg(II) to Hg(0).•Higher water throughputs (>5 times) achieved after membrane pre-treatment.•Minimal contaminated waste was produced=clean environmental technology.
Mercury is a highly toxic heavy metal that causes human health problems and environmental contamination. In this study, an ion exchange membrane bioreactor (IEMB) process was developed to achieve Hg(II) removal from drinking water and industrial effluents. Hg(II) transport through a cation exchange membrane was coupled with its bioreduction to Hg0 in order to achieve Hg removal from concentrated streams, with minimal production of contaminated by-products observed. This study involves (1) membrane selection, (2) demonstration of process effectiveness for removing Hg from drinking water to below the 1ppb recommended limit, and (3) process application for treatment of concentrated water streams, where >98% of the Hg was removed, and the throughput of contaminated water was optimised through membrane pre-treatment. The IEMB process represents a novel mercury treatment technology with minimal generation of contaminated waste, thereby reducing the overall environmental impact of the process.
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