Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

Knowing the ability of water and bile salts to promote the reverse wormlike micelle growth in lecithin/water or lecithin/bile salt mixtures in oil, this work was aimed at elucidating the association properties of the three solutes lecithin, water and the bile salt (BS) sodium deoxycholate in cyclohexane. By systematically changing the fraction of the two additives (i.e.: water and BS) we could identify a region at low additive/lecithin molar ratios where stable wormlike micelle dispersions were formed. Small angle X-ray scattering and oscillatory rheology measurements demonstrated that the ability of bile salt and water to transform the originally spherical lecithin reverse micelles into wormlike micelles and thereby impart to the sample viscoelastic properties is preserved in the three-solute mixture. The results suggest that reverse micelle including both bile salt and water are formed in this system. Reasonably the two primers interact with the same region of the lecithin headgroups and are complementary in altering the packing parameter of the amphiphile to values suitable for the formation of cylindrical aggregates

Estabilidad estructural y P en fracciones de agregados en la cuenca del Aº El Divisorio (Coronel Pringles, BA)

En los últimos años la calidad del agua en el embalse Paso de las Piedras se ha visto afectada por la eutrofización, perjudicando la provisión para la población de Bahía Blanca y alrededores. Se ha señalado a la actividad agropecuaria como originaria del aumento de la concentración de fósforo (P) en el arroyo El Divisorio, que desemboca en el embalse. El objetivo de este estudio fue cuantificar las relaciones entre algunas propiedades relacionadas con el potencial de contaminación de estos suelos: la estabilidad estructural, la distribución de tamaños de agregados y las concentraciones de las formas de P en los diferentes agregados. Se seleccionaron 16 transectas en lotes de productores a lo largo del curso del arroyo. Se tomaron muestras de suelo (0-5 cm) en las posiciones loma (L), media loma (M) y bajo (B). Se determinaron los diámetros medios ponderado en seco (DMPs) y en húmedo (DMPh), calculándose el cambio en el diámetro medio ponderado (CDMP). Se determinaron los contenidos de P orgánico (Po) e inorgánico (Pi) en cada una de las posiciones y tamaños de agregados. Si bien los suelos de la cuenca mostraron buenos valores de estabilidad estructural, las fuerzas físicas provenientes de la actividad agrícola favorecieron la destrucción de los agregados menos estables encontrándose gran cantidad de material fino (<1mm). Esta fracción presentó una importante concentración de P, representando cerca del 30% del total en el suelo. La concentración del Pi fue semejante en todos los tamaños de agregados en las posiciones L y M (200-240 mg kg-1), mientras que fue significativamente superior (360-400 mg kg-1) en los bajos. Estas diferencias podrían estar originadas en texturas distintas y la menor estabilidad de los agregados en los bajos. En cuanto al Po las diferencias fueron menos marcadas, aunque evidenciaron valores más altos en la mayoría de los tamaños de agregados en la posición B. De acuerdo con estos resultados, las pérdidas podrían ser importantes aún con tormentas de poca capacidad erosiva que arrastren materiales menores, ya que estos contribuyen con sustanciales cantidades de P. El mayor cuidado deberá tenerse en los bajos, ya que tienen mayor contenido de P en todas las fracciones y menor estabilidad de los agregados.In the last years, water quality in the Paso de las Piedras reservoir has been affected by eutrophication, leading to problems in the provision of potable water to the population of Bahía Blanca city and surrounding areas. Agricultural activity has been pointed out as the possible non-point source of P contaminating the El Divisorio stream, which flows directly into the reservoir. The objective of this work was to assess some selected edaphic properties associated with the contamination potential of soils such as structural stability, aggregate distribution and concentration of organic (Po) and inorganic (Pi) P in the aggregates. Sixteen locations were selected along the stream in farmers’ fields. Soil samples from the surface 5 cm-layer were collected in the upper, intermediate and lower positions (L, M and B respectively) on each location. Structural stability was determined by the difference between dry and wet mean weight diameters. Soil Po and Pi were measured in each wet aggregate fraction. The values of structural stability were high; however, a great amount of fine material (&lt;1 mm) was present, probably as a consequence of the destruction of less stable aggregates due to agricultural mechanic forces. A large concentration of P was present in this fraction, representing around 30% of total soil P. Pi concentration was similar among all fractions in L and M (200-240 mg P kg-1) while it was significantly higher in B (360-400 mg P kg-1). These differences may be attributed to finer texture and weaker stability in the B positions. Differences among landscape positions were less evident for Po, although greater concentrations were encountered in B in most aggregate fractions. According to these results, P losses could be of significant magnitudes even at low storm intensities, because the small soil particles that are carried in runoff water contribute with great amounts of P. Management practices tending to reduce the impact of agricultural P on water quality should be aimed to reduce the risk related to B positions due to their higher P content and lower structural stability

Variación de las fracciones orgánicas resistentes en suelos de la Región Pampeana

El uso del suelo y la intensidad del manejo influyen en la estabilidad del carbono. En un suelo con labranza continua de la regi&oacute;n semi&aacute;rida pampeana y en otros cuatro con pr&aacute;cticas contrastantes de la regi&oacute;n semi&aacute;rida a h&uacute;meda pampeana, los objetivos fueron: evaluar los cambios de las fracciones org&aacute;nicas con distinto grado de recalcitrancia (carbono org&aacute;nico asociado a la fracci&oacute;n mineral, COM y recalcitrante, COR) y medir el &Iacute;ndice de Recalcitrancia (IR= COM/COR). En el primer caso se us&oacute; un suelo con 23 a&ntilde;os de labranza y uno de referencia, de la EEA Bordenave-INTA. En el segundo los suelos se ubicaron en Bengolea, Monte Buey, Pergamino y Viale, con diferente manejo agr&iacute;cola (Buenas Pr&aacute;cticas y Malas Pr&aacute;cticas) y un Ambiente Natural. La hidr&oacute;lisis &aacute;cida separ&oacute; las fracciones l&aacute;biles y recalcitrantes (COM y COR) y se calcul&oacute; el IR. En el primer caso, el monocultivo de trigo produjo p&eacute;rdida de materiales org&aacute;nicos y aumento de las fracciones resistentes. La labranza no alter&oacute; las fracciones recalcitrantes, a diferencia de la fertilizaci&oacute;n. El IR cambi&oacute; entre a&ntilde;os. El carbono org&aacute;nico total no fue el mejor indicador de los cambios del uso del suelo y las labranzas contribuyeron al descenso del COM. En el segundo caso, las pr&aacute;cticas agr&iacute;colas disminuyeron el carbono respecto al ambiente natural. El carbono total fue m&aacute;s elevado en Viale que en Bengolea. Las mayores p&eacute;rdidas se produjeron en Monte Buey y Pergamino, con menores diferencias entre Buenas y Malas Pr&aacute;cticas. En los 4 sitios, el carbono total y el COM, difirieron entre manejos, pero el COR no se alter&oacute;. El IR mostr&oacute; los menores valores para el suelo natural y los mayores para las rotaciones con mayor proporci&oacute;n de soja. La fracci&oacute;n obtenida por hidr&oacute;lisis &aacute;cida fue lo suficientemente recalcitrante como para no cambiar frente a la mayor&iacute;a de los manejos contrastantes estudiados

Profili di inutilizzabilit&#224; delle intercettazioni anche alla luce della nuova disciplina

Il testo analizza i profili invalidanti le operazioni intercettative comparando la giurisprudenza precedente sui punti modificati dalla legge di riforma

The exposition of religious and cultural symbols according to the political European system. The case Lautsi versus Italy at the European Court of Human Rights

On 3rd November 2009 the European Court of Human Rights in Strasburg ruled that Italy had to remove crucifi xes from school classrooms, thereby supporting the application submitted by Soile Lautsi Albertin, an Italian citizen of Finnish origin, “in the name of the principle of state secularism.” The above decision sparked an uproar and criticism which reverberated throughout entire Europe. On 30th June 2010, an appeal against this ruling, inspired by an ideological vision of religious freedom, had been discussed by Italian government lawyers before the Grand Chambre of the Court of Justice in Strasbourg. The Appeal judgment cancelled the first verdict and recognized the Italian Government’s reasons and rights to display crucifixes in public schools. It was concluded that the first judgment didn’t take into consideration the social and public role of religion, especially the Christian one, in the process of building a civil society and a public law system and promoted religious indifferentism which stands in contradiction with the entire history, culture and rights of the Italian people and the peoples of Europe

Electroactive Materials for Applications in the Field of Wearable Technologies

The objective of this PhD thesis is to present the most performing EAP-based materials, technologies and devices developed by our lab (Ch.4, 5 and 6) also in collaboration with other research groups (Ch.1 and 2) for sensing, actuating and energy harvesting, with reference to their already demonstrated or potential applicability to electronic textiles and wearable technologies in general. Over the last decade great strides have been made in the field of wearable technology: thanks to new discoveries in materials science and miniaturized electronics, tissues and "smart" devices for monitoring vital parameters, rehabilitation and tele-assistance were born. However, a complete and self-powered system, able to exchange information with the external environment, to generate power using the usual movements of the human body (walking, work, sport) and to drive wearable devices, is not yet available on the market and it would find a considerable number of applications (monitoring physiological parameters for athletes and special forces officers in emergency situations, etc.). After a first survey of the state of the art concerning the so-called "smart materials” and technologies currently available for " wearable " activities, the work has developed on three major directives consisting in: energy generation and storage, sensing and actuation. Energy generation and storage. An experimental study, conducted mainly during the first year of PhD, has identified possible candidate materials (piezoelectric PVDF, electret PP) for the energy harvesting and subsequent generation of power from movement and gestures by exploiting the piezoelectric properties of selected materials. These materials have been either found on the market or processed in laboratory. In collaboration with the University of Pavia, a circuit for the storage of electric charges generated was made. Both the commercial materials and those obtained in laboratory were electromechanically tested and the generation of electric charges has been used to develop a demonstrator generator-LED embedded in a shoe. Sensing. During the first and second year, different sensor configurations of "dry" piezoelectric PVDF sensors were tested for the monitoring of vital parameters (heart and breathing rate). Such sensors, prepared in collaboration with the University of Lodz (TUL, Poland), our partners in the PROETEX European project (6th FP 2006-2009), were woven into fabrics to be easily integrated into clothing, and their response was studied. Signal intensities comparable to those of common 3M medical electrodes have been observed. A further development of these materials should be turn to reduce noise, while a computational study might deal with the signal filtering and elimination of motion artifacts. Along with the study of piezoelectric sensors mentioned above, during the third PhD year the production and characterization of dielectric elastomers for sensing applications (artificial skin) was developed too, in collaboration with the Genoa DIST (Dipartimento di Informatica, Sistemistica e Telematica). Such elastomers, characterised by high dielectric constants and restrained compressive elastic moduli, were develop in order to act as dielectric medium in piezocapacitive sensing devices. The obtained materials will be used as artificial skin in robotic systems. Actuating. In parallel with the two lines described above, the activity was concentrated, throughout the period of PhD, on the development of new dielectric elastomer actuators, to be used as high dielectric constant, low elastic modulus and, especially, low electric driving fields devices so that they can be used once inserted inside the clothing (simplified prototype actuators able to change the porosity / texture of different textiles were developed during the first year of activity for the FLEXIFUNBAR European project (6th FP 2005-2008)). The "blend" approach has been privileged over the "composite" approach, previously studied in the master thesis, and has led to promising results both from the applicative point of view, with an increase in the electromechanical performance, and on a fundamental level, for the implications emerging from the interaction between different phases in the study of dielectric response of partially heterogeneous systems. Electromechanical encouraging results were then obtained during the second year of activity with the development of silicone/polyurethane (SI/PU) blends prepared by appropriate volume fractions. Further improvements have also been achieved during the third year of doctoral studies, when it was introduced in the same mixtures a third component, the conjugated polymer poly-(3-hexylthiophene-2,5-dyil) (P3HT), already used by our group for its high polarizability in order to increase the dielectric constant of silicon actuators. The obtained samples, dielectrically, mechanically and electromechanically tested, showed that the conjugated polymer leads to a further significant increase in the electromechanical response of the blend only when added at levels of 1 wt%. This polymer shows, in fact, a certain influence on the microscopic distribution of the SI and PU "phases" in the blend. This effect is maximized for the 1 wt% concentration at which the presence of interfaces is maximized and thus a larger surface polarization, combined with the characteristic high polarizability of P3HT, leads to dielectric constant and strain further implementations. Similar increases in performance, compared to pure components, were also found in mixtures prepared using other polyurethanes and silicones adopting, when necessary, appropriate steps to modify the kinetics of reaction (addition of solvents). The results obtained with this "blending" approach are supported by the Intephase Theory (IT), recently introduced to complete the well known Effective Medium Theory (EMT) which, although applicable to a variety of particle composite structures, is not suitable to describe the behaviour of systems where the presence of an interphase between filler and matrix is significant. The EFT demonstrates that border regions, showing dielectric characteristics different from those of the starting components, can strongly influence the system performance. Through theoretical and experimental evidence, in fact, it is known that, while the inner parts of the matrix polymer chains are able to adopt a configuration that minimizes spontaneous conformational energy, at the interface they are linked or otherwise conditioned in their movements, giving rise to a region where the electrical properties (in some cases also thermal and mechanical) are different from those of both the pure material composing the mixture. During the third year, the production and characterization of elastomeric foams with dielectric properties suitable for sensing (artificial skin) and actuating applications were also developed. The electromechanical performance of these polyurethane-based foams, after appropriate polarization under very high electric fields (Corona poling), were compared with those of two commercial products, which were also subjected to corona poling. Studies have been conducted also on the life of the induced polarization produced by poling in the foam and on the influence of electric field exposure time on the final response of the material. The slightly positive results obtained in terms of increased dielectric constants and strains have opened a new line of activity that represents an innovation in the field of dielectric elastomers, that is the preparation of elastomeric foams with electret properties

Il divieto di domande suggestive e nocive &#232; imposto anche al giudice

La disciplina dell'esame e controesame in sede di testimonianza prevede la inammissibilit\ue0 di alcune tipologie di domande. Lo scritto analizza i limiti dei divieti, in relazione alle parti e al giudice, sulla base della giurisprudenza di legittimit\ue0

La riassunzione della prova dichiarativa in appello : note a margine di Sezioni Unite Troise

Lo scritto riassume il percorso giurisprudenziale, interno ed europeo, sul piano della tutela del contraddittorio in sede di giudizio di appello definito con sentenza che converte la pronuncia di primo grado in senso favorevole o sfavorevole all'imputato. La pronuncia delle Sezioni Unite richiamata nel testo consente di trattare, in base ai principi di diritto sanciti, la compatibilit\ue0 della nuova disposizione introdotta di recente nel codice (art. 603 comma 3 bis c.p.p.) con le norme convenzionali e l'interpretazione che ne \ue8 fornita dalla Corte europea