Ubiquitous Internet in an integrated satellite-terrestrial environment: The SUITED solution

yesThe current Internet architecture appears to not be particularly suited to addressing the emerging needs of new classes of users who wish to gain access to multimedia services made available by ISPs, regardless of their location, while in motion and with a guaranteed level of quality. One of the main objectives of so-called nextgeneration systems is to overcome the limitations of today¿s available Internet by adopting an approach based on the integration of different mobile and fixed networks. The SUITED project moves in this direction since it aims at contributing to the design and deployment of the global mobile broadband system (GMBS), a unique satellite/terrestrial infrastructure ensuring nomadic users access to Internet services with a negotiated QoS. A description of the main features of the GMBS architecture, characterized by the integration of a multisegment access network with a federated ISP network is given in this article. The GMBS multimode terminal is schematically described, and an overview of the so-called QoS-aware mobility management scheme, devised for such a heterogeneous scenario,is provided

Thermodynamic and technical criteria for the optimal selection of the working fluid in a mini-ORC

Waste energy recovery (WER) is a suitable solution to improve the fuel utilization of Internal Combustion Engines (ICEs) by producing an eco-friendly electrical power from an energy source currently wasted. Organic Rankine Cycle (ORC) technology has been developed in the past few years to generate electric power from medium temperature (500 K – 800 K) ICE wasted thermal sources. Working fluid selection represents the first step in the design of an ORC. At the state of the art, authors where not able to select a single optimal organic fluid. This is mainly because of the different thermodynamic conditions of the heat sources which offer wasted thermal energy. This paper proposes a procedure for the ORC system preliminary working fluid selection, which takes into consideration thermodynamics and design parameters of the system components. The study is applied to WER systems specifically designed as bottoming cycles to ICE for transport applications. However, the method is quite general and makes the model easily adaptable to different heat sources. A steady state thermodynamic model of the system is developed via the software MATLAB. A wide variety of organic fluids (OF), such as R245fa, Solkatherm (SES36) and hexane have been investigated to identify the candidate which offers the best recovery opportunity. Regeneration is also included in this work. Results show that recover thermal energy in the regenerator is an essential method to improve power recovery when applying ORC to WER systems. The effect of superheating on the system power output has been investigated as well. It is capable to increase the cycle power output only when coupled with regeneration. The paper shows that the addition of a bottoming ORC to the ICE is convenient both in terms of recovered electric power (up to 14% of the engine nameplate power) and heat source utilization rate (up to 11 % heat source conversion into electricity). In addition, it is shown that water offers lower performance with respect to organic fluids when considering single stage radial expanders

A prova di bomba. Ingegneri, architetti e teorie sulle volte in un cantiere militare di metà Settecento

The article deals with an episode in the construction of the new Citadel in Alessandria, since the 1730s. This essay considers the complex debate that developed on the best form to assign to “bombproof” vaults of the buildings inside the fortified perimeter. In 1756, engineers, architects and State administrators met in a “congress” to discuss whether semi-circular or elliptical designs were to be preferred: while this meeting highlighted a situation of crisis, on the other hand it became a favourable occasion of improvement, and promotion of a truly scientific approach to construction. The need to counteract the effects of the concentrated force due to the bomb impact on the vault extrados introduced a new and never before considered factor, in a debate on vault design which was by then widespread. In respect to the theories (notably Philippe De La Hire’s) then considered as “state of the art”, the problem was approached by considering the newest theoretical developments in balistics. The problem is analyzed by a close reading of the expertises, leading to more general observations on the relationship between science, technology and the architectural professions in the 18th Centur

Pulsed Current Effect on the Hard Anodizing of an AlSi10Mg Aluminum Alloy Obtained via Additive Manufacturing

The hard anodizing treatments of cast Al-Si alloys are notoriously difficult. Indeed, their microstructural features hinder the growth of a uniform, compact, and defect-free anodic oxide. In this paper, AlSi10Mg samples, produced via Gravity Casting (GC) and Additive Manufacturing, i.e., Laser Powder Bed Fusion (L-PBF), were hard anodized in a sulfuric acid bath, in order to verify how the particular microstructure obtained via L-PBF affects the thickness, hardness, compactness, and defectiveness of the anodic oxide. Moreover, for the first time, Pulsed Direct Current (PDC) procedures were used to perform the hard anodizing treatments on additively manufactured AlSi10Mg alloy. Several combinations of temperature and electrical parameters, i.e., current density, frequency, and Duty Cycle, were tested. The anodized samples were characterized through optical microscopy analysis, Scanning Electron Microscopy (SEM) analysis, and accelerated corrosion tests, i.e., Potentiodynamic Polarization (POL) and Electrochemical Impedance Spectroscopy (EIS) measurements. The PDC procedures allowed improvement of the compromise between evenness, compactness, and defectiveness. Among the attempted PDC procedures, a specific combination of electrical parameters and temperature allowed the best results to be obtained, i.e., the highest hardness and the lowest volumetric expansion values without compromising the oxide quality rating and the corrosion resistance behavior. However, none of the attempted PCD strategies allowed the hardness values obtained on samples produced via GC to be reached

Comparison of pure and mixed gas permeation of the highly fluorinated polymer of intrinsic microporosity PIM-2 under dry and humid conditions: Experiment and modelling

This manuscript describes the gas separation performance of PIM-2, a partially fluorinated linear copolymer synthesized from 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethylspirobisindane (TTSBI) and decafluorobiphenyl (DFBP). As one of the early members of the family of polymers of intrinsic microporosity, it had never been tested as a gas separation membrane because of insufficient mechanical resistance. This has been solved only recently, allowing the preparation of robust self-standing films. Molecular modelling studies demonstrated a high fractional free volume (34%) and an elevated surface area (642 m2 g-1), and the latter is in good agreement with experimental BET results. Pure gas permeabilities measured on a fixed-volume time-lag instrument at 1 bar compare well with the results of mixed separation tests on a variable volume setup from 1-6 bar(a). Molecular modelling and independent sorption measurements on a gravimetric sorption balance both show strong dual-mode sorption behaviour, especially for CO2 and to a lesser extent for CH4. Temperature-dependent pure gas permeation measurements show typical Arrhenius behaviour, with a clear increase in the activation energy for diffusion with the increasing molecular size of the gas, indicating high size-selectivity. This is in agreement with the highly rigid PIM structure, determined by AFM force spectroscopy measurements. The dual-mode behaviour results in a moderate pressure dependence of the CO2 permeability and the CO2/N2 and CO2/CH4 selectivity, all slightly decreasing with increasing pressure. The presence of humidity in the gas stream has a remarkable small effect on the membrane performance, which is probably due to the high fluorine content and the consequently low water vapour solubility in the polymer, as confirmed by gravimetric sorption measurements. The manuscript describes an extensive study on the structure-property relationships in PIM-2. © 2019 Elsevier B.V.European Commission, EC Grantová Agentura Ceské Republiky, GA Ä?R: 18-05484S --Research on biogas upgrading presented in this work was supported by EU structural funding in the frame of Operational Programme Research, Development and Education, project No. CZ.02.1.01./0.0/0.0/17_049/0008419 “COOPERATION”. This work was further supported by the CNR-CAS bilateral agreement 2016–2018 “Innovative polymeric membranes for pervaporation and advanced gas and vapour separations” and by the Czech Science Foundation (grant no. 18-05484S ). Appendix A -

18 meses de virtualidad forzada

Los recursos multimediales hacen más atractiva la enseñanza y mediante ellos, se instruye e informa de acuerdo a objetivos previamente planteados. Durante los últimos años se aprecia un crecimiento en la utilización de los espacios virtuales de aprendizaje, en una primera instancia como biblioteca de lectura, donde los docentes pueden hacerles llegar a los alumnos textos o artículos donde leer sobre el tema en cuestión. De a poco se fueron transformando hasta convertirse en herramientas para que los docentes puedan interactuar con los alumnos y enseñarles no solo la materia que están dictando, sino conferir algunas competencias necesarias al alumno para su desarrollo como profesional. Por lo tanto, la educación virtual es una manera de extender el aula y permitirles a los alumnos adquirir competencias, entre ellas: ● Habilidad en el manejo de la plataforma, permitiéndoles una mejor disponibilidad de la información, contenidos y recursos de apoyo. ● Autonomía en el proceso de aprendizaje, los alumnos pueden estudiar a su ritmo cada tema, sin tener la presión de las horas establecidas para dicha tarea. ● Ayuda a una mejor comunicación entre los estudiantes debido a que se pueden hacer trabajos en grupo y entre estudiantes y docentes, ellos saben que fuera del horario de clase pueden hacer una pregunta y esta ser contestada. Información que también puede ser utilizada por otros alumnos a los cuales quizá no se le había planteado esa duda. ● Mediante el trabajo en equipo pueden construir un texto colaborativamente y aprender a seleccionar cuales son las situaciones relevantes y cuales no deben tomar en consideración. Para aprender y para comprender, los estudiantes necesitan criterios, retroalimentación y oportunidades para reflexionar desde el inicio y a lo largo de cualquier secuencia de instrucción. A este proceso David Perkins y Tina Blythe lo llamaron Valoración Continua (Perkins y Blythe, 1994). Al declararse el aislamiento con motivo de la pandemia por Cov-19 debimos rápidamente adecuarnos para realizar el traslado de la enseñanza a las pantallas. Esto nos obligó a tener en cuenta varios aspectos, según las recomendaciones de Fardoun, referentes a: las herramientas de comunicación, contenidos y materiales, herramientas de seguimiento y control, mecanismo de evaluaciones (Fardoun et.al., 2020). Los autores del siguiente escrito desarrollan su tarea docente desde hace más de 30 años en la Química de primer año para las carreras de Ingeniería; y en el desarrollo que sigue se hace referencia exclusivamente a su experiencia en la materia antes mencionada (todo lo expresado a continuación no es opinión de la cátedra, como tampoco pretende representar la experiencia de todos sus docentes).Investigación en Metodologías Alternativas para la Enseñanza de las Ciencia

Un año de pandemia vs uno presencial : Una experiencia personal en química para ingeniería

La realización de una cátedra en función de las TIC`s (tecnologías de información y comunicación) no es meramente un traslado de lo presencial a lo virtual. La realización de una cátedra en función de las TIC`s (tecnologías de información y comunicación) no es meramente un traslado de lo presencial a lo virtual. En el desarrollo que sigue se hace referencia exclusivamente a la experiencia de los autores del presente trabajo en su tarea docente llevada a cabo en una materia de primer año de la facultad de Ingeniería de UNLP; sobre una población de 200 estudiantes por año siendo la totalidad de alumnos de la cátedra de aproximadamente 1500 en el año.Facultad de Ingenierí

Molecular Dynamics Simulation of Solvent-Polymer Interdiffusion. I. Fickian diffusion

The interdiffusion of a solvent into a polymer melt has been studied using large scale molecular dynamics and Monte Carlo simulation techniques. The solvent concentration profile and weight gain by the polymer have been measured as a function of time. The weight gain is found to scale as t^{1/2}, which is expected for Fickian type of diffusion. The concentration profiles are fit very well assuming Fick's second law with a constant diffusivity. The diffusivity found from fitting Fick's second law is found to be independent of time and equal to the self diffusion constant in the dilute solvent limit. We separately calculated the diffusivity as a function of concentration using the Darken equation and found that the diffusivity is essentially constant for the concentration range relevant for interdiffusion.Comment: 17 pages and 7 figure

The European Union, borders and conflict transformation: the case of Cyprus

Much of the existing literature on the European Union (EU), conflict transformation and border dynamics has been premised on the assumption that the nature of the border determines EU intervention and the consequences that flow from this in terms of EU impact. The article aims to transcend this literature through assessing how domestic interpretations influence EU border transformation in conflict situations, taking Cyprus as a case study. Moreover, the objective is to fuse the literature on EU bordering impact and perceptions of the EU’s normative projection in conflict resolution. Pursuing this line of inquiry is an attempt to depart from the notion of borders being constructed solely by unidirectional EU logics of engagement or bordering practices to a conceptualization of the border as co-constituted space, where the interpretations of the EU’s normative projections by conflict parties, and the strategies that they pursue, can determine the relative openness of the EU border

Drug resistance and minimal residual disease in multiple myeloma

Great progress has been made in improving survival in multiple myeloma (MM) patients over the last 30 years. New drugs have been introduced and complete responses are frequently seen. However, the majority of MM patients do experience a relapse at a variable time after treatment, and ultimately the disease becomes drug-resistant following therapies. Recently, minimal residual disease (MRD) detection has been introduced in clinical trials utilizing novel therapeutic agents to measure the depth of response. MRD can be considered as a surrogate for both progression-free and overall survival. In this perspective, the persistence of a residual therapy-resistant myeloma plasma cell clone can be associated with inferior survivals. The present review gives an overview of drug resistance in MM, i.e., mutation of β5 subunit of the proteasome; upregulation of pumps of efflux; heat shock protein induction for proteasome inhibitors; downregulation of CRBN expression; deregulation of IRF4 expression; mutation of CRBN, IKZF1, and IKZF3 for immunomodulatory drugs and decreased target expression; complement protein increase; sBCMA increase; and BCMA down expression for monoclonal antibodies. Multicolor flow cytometry, or next-generation flow, and next-generation sequencing are currently the techniques available to measure MRD with sensitivity at 10-5. Sustained MRD negativity is related to prolonged survival, and it is evaluated in all recent clinical trials as a surrogate of drug efficacy