Estudio técnico-económico de una planta desaladora de agua de mar por ósmosis inversa

En el següent escrit: Estudi técnic-económic d’una planta desaladora d’aigua de mar per osmosis inversa, es pretén donar al lector una idea del procés d’Osmosis Inversa; el qual, ja el podríem ubicar dins dels processos de separació per membranes. Es pretén que aquesta idea sigui el més pràctica possible, sense deixar de banda els aspectes teòrics corresponents, però descartant aquells que, encara tenir relativa importància, l’únic que se aconseguiria amb el seu estudi, seria ampliar el contingut de l’anomenat projecte sense aportarnos això cap benefici relacionat amb l’essència del tema, com es la desalació d’aigua de mar per osmosis inversa. Es per aquest motiu que l’estudi que segueix, es divideix en cinc volums. El primer recull tots els aspectes teórico-práctics, on el lector pot trobar els diferents processos de separació per membranes, les consideracions sobre l’aigua i tot el relacionat amb el fonament fisico-químic que ens pertoca, o sia, la ósmosis inversa: definicions, conceptes bàsics, procés, membranes, etc. L’aspecte pràctic al que ens referim ve reflexat en petits sub-apartats, tals com: neteja eficaç de les membranes, o en seccions posteriors, en petits apartats on es donen recomanacions pràctiques, de instal•lació i inclòs de fabricació d’aparells per postratament. El volum segon és una descripció detalla de l’instal•lació, on s’estudia des de la presa d’aigua de mar fins l’obtenció d’aigua producte, nomenant-se tots els equips, vàlvules, bombes, filtres, etc., que l’aigua travessa en el seu procés. Els tres volums restants corresponen al aspecte més tècnic, on es mostren, por ordre: càlculs, plànols i pressupost o memòria econòmica

Impact of the surface roughness on the electrical capacitance

A new hybrid approach consists to use the advantages of both systems namely the high geometric aspects of the electrodes of the ultracapacitor and the high dielectric strength of polymer materials used in dielectric capacitors. The surface roughness of the electrodes of the ultracapacitor is manufactured with nano-porous materials; activated carbon and carbon nanotubes (CNTs). Many compositions of both carbonaceous materials are tested with different insulating materials (liquid and solid) to constitute the hybrid capacitor. It appears that the capacitance increases with the carbonaceous composition: An increasing from 15 to 40% is observed as compared to a plane capacitor, it can be twice with a 100 wt% of CNTs content. But, the impregnation of the insulating material in the surface roughness remains the key point of the realization of the hybrid capacitor. The roughness accessibility is a major property to optimize in order to improve the impregnation of the insulating material to increase the electrical capacitance

A STUDY OF TECHNIQUES AND THE DEVELOPMENT OF EQUIPMENT FOR DECANNING EBR-II FUEL ELEMENTS

Remotely operated, semi-automatic machines, designed to effect the mechanical disassembly (i.e., decanning) of spent fuel elements from the Experimental Breeder Reactor-II, were developed. The machines described are laboratory models which successfully decanned simulated fuel elements. They are electrically or pneumatically operated and are capable of decanning three fuel elements per minute without the routine use of manipulators. Each machine is made up of functional units which are sequentially placed to eliminate handling between steps of the decanning operation and which are easily removable for replacement or maintenance. In the first of the two machines described, pneumatically operated devices prepare the fuel element for a rotary shearing operation which cuts the tubing jacket along a helical circumferential path as it is being removed. The alternate machine removes the jacket by means of a series of shearing rolls. Both machines are served by auxiliary mechanisms, such as inspection jigs, fuel and scrap choppers, and transfer magazines. (auth

A survey on surgeons' perceived quality of the informed consent process in a Swiss paediatric surgery unit.

AIM: To evaluate the levels of satisfaction and opinions on the usefulness of the informed consent form currently in use in our Paediatric Surgery Department. Qualitative study carried out via interviews of senior paediatric surgeons, based on a questionnaire built up from reference criteria in the literature and public health law. RESULTS: Physicians with between 2 and 35 years experience of paediatric surgery, with a participation rate of 92 %, agreed on the definition of an informed consent form, were satisfied with the form in use and did not wish to modify its structure. The study revealed that signing the form was viewed as mandatory, but meant different things to different participants, who diverged over whom that signature protected. Finally, all respondents were in agreement over what information was necessary for parents of children requiring surgery. CONCLUSION: Paediatric surgeons seemed to be satisfied with the informed consent form in use. Most of them did not identify that the first aim of the informed consent form is to give the patient adequate information to allow him to base his consent, which is a legal obligation, the protection of physicians by the formalisation and proof of the informed consent being secondary. Few surgeons brought up the fact that the foremost stakeholder in paediatric surgery are the children themselves and that their opinions are not always sought. In the future, moving from informed consent process to shared decision-making, a more active bidirectional exchange may be strongly considered. Involving children in such vital decisions should become the norm while keeping in mind their level of maturity

Capacité d’absorption : revue de littérature, opérationnalisation et exploration

La notion de capacité d’absorption a été étudiée d’un point de vue théorique mais n’a pas fait l’objet d’une opérationnalisation qui permette de l’appréhender. En particulier, les quatre dimensions mises en avant par Zahra et George (2002) : acquisition, assimilation, transformation et exploitation ouvrent une voie intéressante. La recherche conduite est de nature exploratoire, c’est pourquoi les cas de 10 entreprises innovantes sont ici étudiés. Dans une première partie de ce papier, nous resituerons les capacités d’absorption comme part des capacités dynamiques et proposerons une revue de la littérature. Dans la seconde partie, nous chercherons à opérationnaliser la notion de capacité d’absorption afin de tendre vers la construction d’un outil de mesure puis nous intéresserons aux liens entre la stratégie de l’entreprise et sa capacité d’absorption. Enfin, nous mettons en évidence 2 dimensions de la capacité d’absorption ignorées par la littérature

Symmetry of bound and antibound states in the semiclassical limit

We consider one dimensional scattering and show how the presence of a mild positive barrier separating the interaction region from infinity implies that the bound and antibound states are symmetric modulo exponentially small errors in 1/h. This simple result was inspired by a numerical experiment and we describe the numerical scheme for an efficient computation of resonances in one dimension