Adsorption of carbon dioxide, methane, and nitrogen on zn(Dcpa) metal-organic framework

Norma Transitória DL 57/2016 ELAC2014/BEE0367Adsorption-based processes using metal-organic frameworks (MOFs) are a promising option for carbon dioxide (CO2 ) capture from flue gases and biogas upgrading to biomethane. Here, the adsorption of CO2, methane (CH4 ), and nitrogen (N2 ) on Zn(dcpa) MOF (dcpa (2,6-dichloro-phenylacetate)) is reported. The characterization of the MOF by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and N2 physisorption at 77 K shows that it is stable up to 650 K, and confirms previous observations suggesting framework flexibility upon exposure to guest molecules. The adsorption equilibrium isotherms of the pure components (CO2, CH4, and N2 ), measured at 273–323 K, and up to 35 bar, are Langmuirian, except for that of CO2 at 273 K, which exhibits a stepwise shape with hysteresis. The latter is accurately interpreted in terms of the osmotic thermodynamic theory, with further refinement by assuming that the free energy difference between the two metastable structures of Zn(dcpa) is a normally distributed variable due to the existence of different crystal sizes and defects in a real sample. The ideal selectivities of the equimolar mixtures of CO2 /N2 and CO2 /CH4 at 1 bar and 303 K are 12.8 and 2.9, respectively, which are large enough for Zn(dcpa) to be usable in pressure swing adsorption.publishersversionpublishe

Two-column relay simulated moving-bed for gas-phase separations

A new two-column, relay, simulated moving bed process (2-column R-SMB) for gas-phase separations has been designed and implemented experimentally in this work. R-SMB differs from classical SMB processes by avoiding the partial withdrawal of products, since the outlet streams are handled in a relay mode. The outlet streams are either fully collected as product/waste or completely recycled to another column. In this work, the relay concept is applied for the first time in 2-column SMB processes and gas-phase separations. The process is designed and optimized through model-based computational simulation and the results obtained are validated experimentally. For the purpose, a new experimental lab-scale unit was designed and assembled. Please click Additional Files below to see the full abstract

A ubiquitous learning approach on robotics

Ubiquitous learning refers to the integration of learning processes with everyday environments and activities using technology. By leveraging ubiquitous learning principles in the field of robotics, we can foster an immersive and interactive learning environment that promotes continuous learning and knowledge acquisition. This paper presents an in-depth exploration of a ubiquitous learning approach for robotics with the aim to enhance the educational experiences and capabilities of robotic systems. Furthermore, it explores the potential benefits and challenges of ubiquitous learning in the field of robotics, such as increased adaptability, personalized learning experiences, and the development of lifelong learning skills. The results indicate that a ubiquitous learning approach can significantly enhance the learning capabilities of students.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio

Sorption of fluorinated greenhouse gases in silica-supported fluorinated ionic liquids

the contracts of Individual Call to Scientific Employment Stimulus 2020.00835.CEECIND (J.M.M.A.) / 2021.01432.CEECIND (A.B.P.), the Norma Transitória DL 57/2016. Publisher Copyright: © 2022 The Authors.The Kigali Amendment to the Montreal Protocol limits the global use of fluorinated greenhouse gases (F-gases) and encourages the development of a new generation of refrigerants with lower global warming potential. Therefore, there is a need to develop efficient and sustainable technologies to selectively capture and recycle the F-gases as new environmentally sustainable refrigerants. Here, ionic liquids (ILs) with high F-gas uptake capacity and selectivity were supported on silica and their potential as media for selective F-gas sorption was studied. For this purpose single-component sorption equilibria of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a) were measured at 303.15 K by gravimetry. The sorption data were successfully correlated using classical models of sorption thermodynamics. The results show that the IL supported in the porous volume and on the external surface of the porous silica controls the F-gas uptake in the composites and that changing the IL's cations and anions allows fine-tuning the selectivity of the sorption process. This work brings crucial knowledge for the development of new materials based on ILs for the selective sorption of F-gases.publishersversionpublishe

Absorption of Fluorinated Greenhouse Gases Using Fluorinated Ionic Liquids

funding of the KET4F-Gas project, SOE2/P1/P0823, co -funded by the Interreg Sudoe Programme through the European Regional Development Fund (ERDF). FCT/MCTES for financial support through IF/00190/2014 , IF/00210/2014 financial support through the Norma TransitOria DL 57/2016 Program Contract (FCT/MCTES). FCT/MCTES (UID/QUI/50006/2019).The increasing awareness of the environmental impact of fluorinated gases (F-gases) used in refrigeration is instigating the development of technologies to recover and recycle them. With this goal in mind, single-component absorption equilibrium isotherms at 303.15 K of F-gases in different ionic liquids (ILs) were determined using a gravimetric method. The selected F-gases are the most used in domestic refrigeration (R-32: difluoromethane, R-125: pentafluoroethane, and R-134a: 1,1,1,2-tetrafluoroethane). The results show that ILs containing a fluorinated alkyl side chain with four carbon atoms, that is, fluorinated ILs (FILs), have higher gas absorption capacity than conventional fluoro-containing ILs. All studied ILs showed ideal selectivity toward R-134a. Conventional fluoro-containing ILs showed better selectivities for the separation of the binary mixtures R-134a/R-125 and R-32/R-125, and FILs showed better selectivities for the R-134a/R-32 mixture. These results provide fundamental knowledge of the behavior of these new alternative solvents and key information for their application in the separation of F-gas mixtures of commercial refrigerants.authorsversionpublishe

Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways

Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70-1143, and it describes the initial molecular events that may trigger the increased drought tolerance in the host plant

Systematic review and meta-analysis of the use of prokinetics in gastroesophageal reflux and in gastroesophageal reflux disease in Pediatrics

OBJECTIVE: To evaluate, by systematic review and meta-analysis, randomized studies comparing the prokinetics (domperidone, bromopride, metoclopramide and bethanechol) to placebo in the treatment of gastroesophagic reflux (GER) and gastroesophagic reflux disease (GERD) in children. METHODS: Bibliographic search for randomized clinical trials (Medline, EMBASE, Biological Abstracts, ISI/Web of Science, CINAHL, Lilacs e Cochrane). The primary outcome was the modification of reflux symptoms. Other outcomes were: GER-related complications, alterations in control exams, life quality, adverse events and abandon of treatment. RESULTS: The metanalysis included four studies on domperidone, two on metoclopramide, and one on bethanechol. No study of bromopride was retrieved. The risk of non-response to the treatment was significantly smaller in children that received prokinetics in comparison to placebo (RR 0.35, 95%CI 0.14-0.88). Individual therapeutic advantage regarding placebo was related to domperidone (n=126; RR 0.27; 95%CI 0.14-0.52, NNT 3; I2 0%) and bethanechol (n=44; RR 0.19; 95%CI 0.05-0.55; NNT 2), but not to metoclopramide (n=71; RR 0.63; 95%CI 0.07-5.71; I2 92.2%). CONCLUSIONS: The evidence for prokinetic use in GER and GERD in children is limited because the few studies report preliminary trials that evaluate short-term responses and show methodological limitations.OBJETIVO: Avaliar, por meio de revisão sistemática e metanálise, estudos randomizados que comparam os procinéticos domperidona, bromoprida, metoclopramida e betanecol ao placebo no tratamento do refluxo gastroesofágico (RGE) e da doença do refluxo gastroesofágico (DRGE) em crianças. MÉTODOS: BUsca bibliográfica de ensaios clínicos randomizados (Medline, EMBASE, Biological Abstracts, ISI/Web of Science, CINAHL, Lilacs e Cochrane). O desfecho primário foi eficácia na modificação dos sintomas de refluxo, conforme definição de autores das fontes primárias. Outras variáveis de interesse foram: complicações relacionadas ao RGE, alterações nos exames laboratoriais de controle, qualidade de vida, eventos adversos e abandono do tratamento. RESULTADOS: Foram incluídos quatro estudos com domperidona, dois com metoclopramida, um com betanecol. Nenhum estudo com bromoprida foi localizado. O risco de não resposta ao tratamento foi significativamente menor para os procinéticos quando comparados ao placebo (RR 0,35; IC95% 0,14-0,88). A vantagem terapêutica individual em relação ao placebo se manteve para a domperidona (n=126; RR 0,27; IC95% 0,14-0,52; NNT 3; I2 0%) e betanecol (n=44, RR 0,19, IC95% 0,05-0,55, NNT 2), mas não para metoclopramida (n=71; RR 0,63; IC95% 0,07-5,71, I2 92,2%). CONCLUSÕES: A evidência para o uso de procinéticos no RGE e na DRGE em crianças é limitada, pois os poucos estudos são ensaios preliminares de resposta em curto prazo e com limitações metodológicas.UFPel Centro de Medicina Baseada em EvidênciasHospital de Clínicas de Porto Alegre Instituto Nacional de Ciência e Tecnologia Translacional em MedicinaUFRJ Instituto de PsiquiatriaUNIFESP Departamento de PsiquiatriaUNIFESP, Depto. de PsiquiatriaSciEL

Exploring the Potential of Metal–Organic Frameworks for the Separation of Blends of Fluorinated Gases with High Global Warming Potential

Funding Information: The authors acknowledge the financial support from the LIFE‐4‐Fgases project, LIFE20 CCM/ES/001748, funded by EU LIFE Programme. This work was also financed by national funds from FCT/MCTES (Portugal) through Associate Laboratory for Green Chemistry–LAQV (UIDB/50006/2020 | UIDP/50006/2020), the contracts of Individual Call to Scientific Employment Stimulus 2020.00835.CEECIND (J.M.M.A.)/2021.01432.CEECIND (A.B.P.), and the Norma Transitória DL 57/2016 Program Contract (R.P.P.L.R.). Publisher Copyright: © 2022 The Authors. Global Challenges published by Wiley-VCH GmbH.The research on porous materials for the selective capture of fluorinated gases (F-gases) is key to reduce their emissions. Here, the adsorption of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a) is studied in four metal–organic frameworks (MOFs: Cu-benzene-1,3,5-tricarboxylate, zeolitic imidazolate framework-8, MOF-177, and MIL-53(Al)) and in one zeolite (ZSM-5) with the aim to develop technologies for the efficient capture and separation of high global warming potential blends containing these gases. Single-component sorption equilibria of the pure gases are measured at three temperatures (283.15, 303.15, and 323.15 K) by gravimetry and correlated using the Tóth and Virial adsorption models, and selectivities toward R-410A and R-407F are determined by ideal adsorption solution theory. While at lower pressures, R-125 and R-134a are preferentially adsorbed in all materials, at higher pressures there is no selectivity, or it is shifted toward the adsorption R-32. Furthermore, at high pressures, MOF-177 shows the highest adsorption capacity for the three F-gases. The results presented here show that the utilization of MOFs, as tailored made materials, is promising for the development of new approaches for the selective capture of F-gases and for the separation of blends of these gases, which are used in commercial refrigeration.publishersversionepub_ahead_of_prin