Optimal Design of a Hybrid Membrane System Combining Reverse and Forward Osmosis for Seawater Desalination

In this work we study Forward Osmosis (FO) as an emerging desalination technology, and its capability to replace totally or partially Reverse Osmosis (RO) in order to reduce the great amount of energy required in the current desalination plants. For this purpose, we propose a superstructure that includes both membrane based desalination technologies, allowing the selection of only one of the technologies or a combination of both of them seeking for the optimal configuration of the network. The optimization problem is solved for a seawater desalination plant with a given fresh water production. The results obtained show that the optimal solution combines both desalination technologies to reduce not only the energy consumption but also the total cost of the desalination process in comparison with the same plant but operating only with RO.

Characterisation of montmorillonites simultaneously modified with an organic dye and an ammonium salt at different dye/salt ratios. Properties of these modified montmorillonites EVA nanocomposites

In this work, a sodium montmorillonite (Na+-Mt) was modified with two molecules simultaneously, an organic dye, methylene blue (MB), and ethyl hexadecyl dimethyl ammonium (EHDDMA). The synthesised organo-montmorillonites (OMt) combining different proportions of the two molecules were thoroughly characterised and mixed with ethylene vinyl acetate copolymer (EVA) in order to check the ability of these OMt as pigments and reinforcing additives. The synthesised OMt combining both surfactants, MB and EHDDMA, present higher interlayer distances than those with only MB, which were employed in previous works as nanopigments. When these OMt were incorporated in the EVA matrix, the obtained clay polymer nanocomposites (CPN) showed a high exfoliation degree of the OMt in the polymer, in such a way that at 80% of the cationic exchange capacity (CEC) of the Mt exchanged with EHDDMA, most of the OMt was exfoliated. Moreover, all the obtained CPN showed an increase in the Young's Moduli compared to the EVA reference, and especially those containing higher amounts of MB. The thermal stability of the CPN also increases with the MB content, compared to other CPN including conventional surfactants. The hiding power and colouring power achieved in the CPN are higher even with a much lower load of MB when EHDDMA is exchanged in the Mt.

Gasification and Pyrolysis of Posidonia oceanica in the Presence of Dolomite

Resumen del póster presentado en Symposium on Renewable Energy and Products from Biomass and Waste, CIUDEN (Cubillos de Sil, León, Spain), 12-13 May 2015

Electrochemical reactions of catechol, methylcatechol and dopamine at tetrahedral amorphous carbon (ta-C) thin film electrodes

The electrochemical reactions of dopamine, catechol and methylcatechol were investigated at tetrahedral amorphous carbon (ta-C) thin film electrodes. In order to better understand the reaction mechanisms of these molecules, cyclic voltammetry with varying scan rates was carried out at different pH values in H2SO4 and PBS solutions. The results were compared to the same redox reactions taking place at glassy carbon (GC) electrodes. All three catechols exhibited quasi-reversible behavior with sluggish electron transfer kinetics at the ta-C electrode. At neutral and alkaline pH, rapid coupled homogeneous reactions followed the oxidation of the catechols to the corresponding o-quinones and led to significant deterioration of the electrode response. At acidic pH, the extent of deterioration was considerably lower. All the redox reactions showed significantly faster electron transfer kinetics at the GC electrode and it was less susceptible toward surface passivation. An EC mechanism was observed for the oxidation of dopamine at both ta-C and GC electrodes and the formation of polydopamine was suspected to cause the passivation of the electrodes.

Simulated magnetic field expulsion in neutron star cores

The study of long-term evolution of neutron star (NS) magnetic fields is key to understanding the rich diversity of NS observations, and to unifying their nature despite the different emission mechanisms and observed properties. Such studies in principle permit a deeper understanding of the most important parameters driving their apparent variety, e.g. radio pulsars, magnetars, X-ray dim isolated NSs, gamma-ray pulsars. We describe, for the first time, the results from self-consistent magnetothermal simulations considering not only the effects of the Hall-driven field dissipation in the crust, but also adding a complete set of proposed driving forces in a superconducting core. We emphasize how each of these core-field processes drive magnetic evolution and affect observables, and show that when all forces are considered together in vectorial form, the net expulsion of core magnetic flux is negligible, and will have no observable effect in the crust (consequently in the observed surface emission) on megayear time-scales. Our new simulations suggest that strong magnetic fields in NS cores (and the signatures on the NS surface) will persist long after the crustal magnetic field has evolved and decayed, due to the weak combined effects of dissipation and expulsion in the stellar core.

Titania–Silica Materials for Enhanced Photocatalysis

Mesoporous titania–organosilica nanoparticles comprised of anatase nanocrystals crosslinked with organosilica moieties have been prepared by direct co-condensation of a titania precursor, tetrabuthylortotitanate (TBOT), with two organosilica precursors, 1,4-bis(triethoxysilyl) benzene (BTEB) and 1,2-bis(triethoxysilyl) ethane (BTEE), in mild conditions and in the absence of surfactant. These hybrid materials show both high surface areas (200–360 m2 g−1) and pore volumes (0.3 cm3 g−1) even after calcination, and excellent photoactivity in the degradation of rhodamine 6G and in the partial oxidation of propene under UV irradiation, especially after the calcination of the samples. During calcination, there is a change in the TiIV coordination and an increase in the content of Si[BOND]O[BOND]Ti moieties in comparison with the uncalcined materials, which seems to be responsible for the enhanced photocatalytic activity of hybrid titania–silica materials as compared to both uncalcined samples and the control TiO2.

A Sequential Algorithm for the Rigorous Design of Thermally Coupled Distillation Sequences

A sequential design method is presented for the design of thermally coupled distillation sequences. The algorithm starts by selecting a set of sequences in the space of basic configurations in which the internal structure of condensers and reboilers is explicitly taken into account and extended with the possibility of including divided wall columns (DWC). This first stage is based on separation tasks (except by the DWCs) and therefore it does not provide an actual sequence of columns. In the second stage the best arrangement in N-1 actual columns is performed taking into account operability and mechanical constraints. Finally, for a set of candidate sequences the algorithm try to reduce the number of total columns by considering Kaibel columns, elimination of transfer blocks or columns with vertical partitions. An example illustrate the different steps of the sequential algorithm.

Large scale optimization of a sour water stripping plant using surrogate models

In this work, we propose a new methodology for the large scale optimization and process integration of complex chemical processes that have been simulated using modular chemical process simulators. Units with significant numerical noise or large CPU times are substituted by surrogate models based on Kriging interpolation. Using a degree of freedom analysis, some of those units can be aggregated into a single unit to reduce the complexity of the resulting model. As a result, we solve a hybrid simulation-optimization model formed by units in the original flowsheet, Kriging models, and explicit equations. We present a case study of the optimization of a sour water stripping plant in which we simultaneously consider economics, heat integration and environmental impact using the ReCiPe indicator, which incorporates the recent advances made in Life Cycle Assessment (LCA). The optimization strategy guarantees the convergence to a local optimum inside the tolerance of the numerical noise.

Educación para el espírito empreendedor : informe de una experiencia en una Institución de Educación Superior

El concepto de espíritu emprendedor se entiende actualmente como una competencia transversal, fundamental para el desarrollo humano, social y económico. Sin embargo, tradicionalmente se há asociado solo a las áreas económicas y de negocios, a pesar de que venimos observando un cambio gradual en esta concepción. Así, en la última década, se ha producido un verdadero incremento en el papel de la educación para el desarrollo de las competencias relacionadas con el espíritu emprendedor, puesto que pueden y deben ser aprendidas y desarrolladas desde muy pronto. Este reconocimiento de la importancia de la educación en el desarrollo del espíritu emprendedor otorga una nueva responsabilidad a las instituciones educativas, en particular a la educación superior. Es precisamente sobre la educación del espíritu emprendedor en la educación superior que este artículo habla. El artículo presenta el ejemplo de dos centros (Centro de Aprendizaje y Desarrollo de la Infancia-CeADIn y el Centro de Ciencia, Tradición & Cultura-CT&C) de la misma institución de educación superior que, aunque con una estructura de organización, objetivos, estrategias y formas de trabajo diversas, tienen algunos puntos en común, como el hecho de que pretenden educar para el espíritu emprendedor tanto a niños, como a jóvenes y adultos, involucrando en este proceso a los alumnos de los cursos de formación del profesorado.

Address, 1789 May 21

Handwritten four-page draft of an address by Eliphalet Pearson. The address, made on behalf of the Harvard Corporation, relays the resolution of the Board of Overseers regarding the hours during which students should be in their chambers, restrictions on their ability to go into town, and emphasizing the College government's "fervent wish to see virtue & order prevalent among the students of this society." The introduction discusses the expectations of parents for their children to receive "a polite, virtuous, & religious education" instead of "sending him to a place, which is said to be noted for rudeness, vice, & irreligion."

Shopping malls and neoliberal trends in Southern European cities: Post-metropolitan challenges for urban planning policy

Whilst shopping malls have been explored at length by critical urban studies, there has been little exploration of their role in restructuring the practice of urban and spatial planning. This article uses the shopping mall as an object of study in the light of the neoliberal trends and post-metropolisation in Southern Europe, with the aim of exploring challenges for urban governance and planning practice and with a focus on the role of the ongoing economic crisis. A threefold exploratory framework – the ‘lost-in-time scenario’, the ‘messianic mall model’ and the ‘(im)mature planning explanation’ – is used to make sense of the local versions of shopping mall development in Lisbon (Portugal) and Palermo (Southern Italy). According to findings, we highlight the clash between the multi-scalar nature of shopping malls and the dominance of the municipal scale in regulatory planning frameworks, and the risk that shopping mall development (at least in Southern Europe) may replicate uneven development patterns, reproducing the pre-conditions of the crisis without helping to overcome it.

Who reads Tocqueville today?

Esta comunicação irá ser publicada no próximo número da Newsletter do RC16 Sociological Theory da International Sociological Association, em Dezembro de 2016.

Extending working life in Belgium. CEPS Working Document No. 386, 22 November 2013

This report aims at understanding how persons aged 50 years and older are and can be integrated into the working society in Belgium. We are interested in how people in this age group can be induced to engage in various forms of employment and lifelong learning. Based on secondary literature, descriptive databases as well as interviews with experts and focus groups, we find that the discussion on active ageing in Belgium is well advanced with numerous contributions by academics, stakeholders, social partners, the public administration and interest groups. The wish to retire at 60 is widely shared, but at the same time the majority of Belgium’s elderly are able and would be willing to work under specific conditions. Therefore, we recommend that Belgium should invest in more flexible systems including a revision of the tax scheme, such as the part-time retirement system proposed by the insurance company Delta Lloyd. An equally relevant recommendation would be to ensure that public employment agencies, employers and agencies that provide training encourage all workers to work and learn regardless of their age.

Turkey after the start of negotiations with the European Union - foreign relations and the domestic situation, Part II. OSW Report, July 2008

The Centre for Eastern Studies has decided to embark on the project entitled 'Turkey after the start of negotiations with the European Union - foreign relations and the domestic situation' for two major reasons: the start of the accession negotiations between Ankara and the European Union in October 2005, and the significant part which Turkey plays in western Eurasia (the Caucasus, the countries in the basins of the Black and Caspian Seas, the Middle East and the Balkans) which We wish to present our readers our second report discussing Turkey's relations with Central Asia, the Caucasus and Russia, the aspect of Turkish foreign policy regarding the Black Sea, and the role of Turkey as a transit country for oil and gas from the Middle East and the Caspian regions. The evaluation of Turkey's standpoint and potential regarding the aforementioned issues is especially important, considering the tensions existing in Turkey's relations with the EU and the USA, as well as the West's increasing engagement in the Caucasus, Central Asia and Black Sea regions. In this process, Ankara may play the role of a significant ally for the West. However, it may just as readily play the role of its rival, who could co-operate with other countries and may seriously frustrate the implementation of the EU and US' goals. The Report was developed between autumn 2006 and autumn 2007, over which time the project participants searched for publicly available documents in Poland, Turkey, EU countries and the USA, and went on five research trips to Central Asia, Russia, Turkey and Caucasus, where they met local analysts, officials and researchers.

How returns from tertiary education differ by field of study. Implications for policy-makers and students. CEPS Working Document No. 411/July 2015

With the huge growth in enrolment in higher education, the key question facing young people today is not so much “what to study” as “whether to study”. Taking a methodologically innovative approach, this paper measures the net present value of university education and compares returns from studying a range of different subjects. We use data from 5 European countries (France, Italy, Hungary, Poland and Slovenia) and include (opportunity) costs in the computation. Results suggest that enrolling in science, technology, engineering and mathematics (STEM) courses is often not the best investment for students, especially female students. In choosing what to study, therefore, students are taking decisions that are consistent with their own private returns. This suggests that policymakers should consider changing the incentives offered if they wish to change students’ behaviour.