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The building climatization and its influence on energy consumption have consequences on the environment due to the emission of greenhouse gases. Improving the efficiency of this sector is essential to reduce the effect on climate change. In recent years, the interest in porous materials in applications such as heat pumps has increased because of their promising potential. To assess the performance of adsorption heat pumps and cooling systems, here we discuss a multistep approach based on the processing of adsorption data combined with a thermodynamic model. The process provides properties of interest, such as the coefficient of performance, the working capacity, the specific heat or cooling effect, or the released heat upon adsorption and desorption cycles, and it also has the advantage of identifying the optimal conditions for each adsorbent–fluid pair. To test this method, we select several metal-organic frameworks that differ in topology, chemical composition, and pore size, which we validate with available experiments. Adsorption equilibrium curves were calculated using molecular simulations to describe the adsorption mechanisms of methanol and ethanol as working fluids in the selected adsorbents. Then, using a thermodynamic model we calculate the energetic properties combined with iterative algorithms that simultaneously vary all the required working conditions. We discuss the strong influence of operating temperatures on the performance of heat pump devices. Our findings point to the highly hydrophobic metal azolate framework MAF-6 as a very good candidate for heating and cooling applications for its high working capacity and excellent energy efficiency. [ABSTRACT FROM AUTHOR]

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Separation of volatile organic compounds is one of the most studied processes in industry. TAMOF-1 is a homochiral metal-organic framework with a crystalline network of interconnected ≈1 nm channels and has high thermal and chemical stability. Thanks to these features, it can resolve racemic mixtures of chiral drugs as a chiral stationary phase in chromatography. Interestingly, the particular shape and size of its channels, along with the presence of metallic centers and functional groups, allow establishing weak but significant interactions with guest molecules. This opens interesting possibilities not only to resolve racemates but also to separate other organic mixtures, such as saturated/unsaturated and/or linear/branched molecules. In search of these applications, we have studied the separation of volatile organic compounds in TAMOF-1. Monte Carlo simulations in the grand-canonical ensemble have been carried out to evaluate the separation of the selected molecules. Our results predict that TAMOF-1 is able to separate xylene isomers, hexane isomers, and benzene-cyclohexane mixtures. Experimental breakthrough analysis in the gas phase and also in the liquid phase confirms these predictions. Beds of TAMOF-1 are able to recognize the substitution in xylenes and the branching in hexanes, yielding excellent separation and reproducibility, thanks to the chemical and mechanical features of this material.

The stability of metal-organic frameworks is a key factor in many applications in some fields that require working under harsh conditions. It is known that a large number of MOFs are vulnerable to humid air. It means that when they are exposed to water, a structural collapse of the crystal happens. In this work, Molecular Dynamics simulations using a reactive force field have been performed to study the stability of MOF-74 against the adsorption of catechol, resorcinol and hydroquinone in the presence of water. We reproduced the water instability of Zn-MOF-74 and we studied the resistance of the structure. Our simulations showed that the three isomers generate a volume change in the framework but the structural collapse does not happen. In contrast, for water-isomer mixtures, there is structural collapse. Not only do catechol, resorcinol and hydroquinone not behave as stabilizing agents but they do enhance the hydration effect on the structure.

Objective: understand the everyday and the imaginary of Nursing students in their knowledge socialization process through the Problem-Based Learning (PBL) strategy., Method: Action Research, involving 86 students from the second year of an undergraduate Nursing program in Spain. A Critical Incident Questionnaire and Group interview were used. Thematic/categorical analysis, triangulation of researchers, subjects and techniques., Results: the students signal the need to have a view from within, reinforcing the criticism against the schematic dualism; PBL allows one to learn how to be with the other, with his mechanical and organic solidarity; the feeling together, with its emphasis on learning to work in group and wanting to be close to the person taking care., Conclusions: The great contradictions the protagonists of the process, that is, the students experience seem to express that group learning is not a form of gaining knowledge, as it makes them lose time to study. The daily, the execution time and the imaginary of how learning should be do not seem to have an intersection point in the use of Problem-Based Learning. The importance of focusing on the daily and the imaginary should be reinforced when we consider nursing education.

Infectious diseases, as tuberculosis, and metastatic cancers are the main causes of multiple pulmonary micronodules on chest radiographs. Many cancers can produce this anomaly, but the most common are thyroid, melanoma and gastrointestinal (colon and pancreas). Hepatocellular carcinoma can produce lung metastasis, but seldom makes bilateral pulmonary micronodules. Here we present the case of a woman with a hepatocarcinoma that appeared as a bilateral micronodular disease on the chest radiograph.