Morphological and Structural Evaluation of Hydration/Dehydration Stages of MgSO4 Filled Composite Silicone Foam for Thermal Energy Storage Applications

Salt hydrates, such as MgSO4·7H2O, are considered attractive materials for thermal energy storage, thanks to their high theoretical storage density. However, pure salt hydrates present some challenges in real application due to agglomeration, corrosion and swelling problems during hydration/dehydration cycles. In order to overcome these limitations, a composite material based on silicone vapor-permeable foam filled with the salt hydrate is here presented. For its characterization, a real-time in situ environmental scanning electron microscopy (ESEM) investigation was carried out in controlled temperature and humidity conditions. The specific set-up was proposed as an innovative method in order to evaluate the morphological evolution of the composite material during the hydrating and dehydrating stages of the salt. The results evidenced an effective micro-thermal stability of the material. Furthermore, dehydration thermogravimetric/differential scanning calorimetric (TG/DSC) analysis confirmed the improved reactivity of the realized composite foam compared to pure MgSO4·7H2O.This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31). This work was partially supported by ICREA under the ICREA Academia program

MgSO4·7H2O filled macro cellular foams: An innovative composite sorbent for thermo-chemical energy storage applications for solar buildings

For seasonal energy storage using solar energy in buildings heating and DHW, thermochemical technology represents the most promising alternative due to the virtually absence of heat losses during storage period. This work focuses on silicone foams, filled by MgSO4·7H2O, as innovative composite sorbents for sorption thermal energy storage applications. The necessity to enclose the salt hydrate in the polymeric foam arises for overcoming the issue of swelling, agglomeration, and/or deliquescence of the salt during its de/hydration process. Indeed, the foam with its flexible structure allows the safe volume expansion during the hydration phase of the salt. The foam samples presented in this paper were obtained by mixing the salt hydrate at various percentages (from 40 wt% up to 70 wt%) with a mixture of two water vapour permeable silicones. The foams were characterized by a complete physicochemical and morphological examination in order to evaluate their actual application in sorption energy storage systems. It was demonstrated that a good link seems to be established between the foam and the salt, and that the de/hydration capacity of the salt is not hindered by the foaming process, storage ability and storage density of the composites are expected to be in line with those of the pure material.The present work has been partially funded by PON “Ricerca e Competitività 2007-13” PON03PE_00206_2 S5 – Smart Small Scale Solar Systems and by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)). The authors from the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). Aran Solé would like to thank Ministerio de Economía y Competitividad de España for Grant Juan de la Cierva, FJCI-2015-25741

Novel implantable pressure and acceleration sensor for bladder monitoring

Objectives To test the hypothesis that an implantable sensing system containing accelerometers can detect small‐scale autonomous movements, also termed micromotions, which might be relevant to bladder physiology. Methods We developed a 6‐mm submucosal implant containing a pressure sensor (MS5637) and a triaxial accelerometer (BMA280). Sensor prototypes were tested by implantation in the bladders of Gottingen minipigs. Repeated awake voiding cystometry was carried out with air‐charged catheters in a standard urodynamic set‐up as comparators. We identified four phases of voiding similar to cystometry in other animal models based on submucosal pressure. Acceleration signals were separated by frequency characteristics to isolate linear acceleration from the baseline acceleration. The total linear acceleration was calculated by the root mean square of the three measurement axes. Acceleration activity during voiding was investigated to adjacent 1‐s windows and was compared with the registered pressure. Results We observed a total of 19 consecutive voids in five measurement sessions. A good correlation (r > 0.75) was observed between submucosal and catheter pressure in 14 of 19 premicturition traces. The peak‐to‐peak interval between maximum total linear acceleration was correlated with the interval between submucosal voiding pressure peaks (r = 0.760, P < 0.001). The total linear acceleration was higher during voiding compared with pre‐ and postmicturition periods (start of voiding/phase 1). Conclusions To the best of our knowledge, this is the first report of bladder wall acceleration, a novel metric that reflects bladder wall movement. Submucosal sensors containing accelerometers can measure bladder pressure and acceleration

Novel implantable pressure and acceleration sensor for bladder monitoring

Abstract Objectives To test the hypothesis that an implantable sensing system containing accelerometers can detect small-scale autonomous movements, also termed micromotions, which might be relevant to bladder physiology. Methods We developed a 6-mm submucosal implant containing a pressure sensor (MS5637) and a triaxial accelerometer (BMA280). Sensor prototypes were tested by implantation in the bladders of Gottingen minipigs. Repeated awake voiding cystometry was carried out with air-charged catheters in a standard urodynamic set-up as comparators. We identified four phases of voiding similar to cystometry in other animal models based on submucosal pressure. Acceleration signals were separated by frequency characteristics to isolate linear acceleration from the baseline acceleration. The total linear acceleration was calculated by the root mean square of the three measurement axes. Acceleration activity during voiding was investigated to adjacent 1-s windows and was compared with the registered pressure. Results We observed a total of 19 consecutive voids in five measurement sessions. A good correlation (r > 0.75) was observed between submucosal and catheter pressure in 14 of 19 premicturition traces. The peak-to-peak interval between maximum total linear acceleration was correlated with the interval between submucosal voiding pressure peaks (r = 0.760, P < 0.001). The total linear acceleration was higher during voiding compared with pre- and postmicturition periods (start of voiding/phase 1). Conclusions To the best of our knowledge, this is the first report of bladder wall acceleration, a novel metric that reflects bladder wall movement. Submucosal sensors containing accelerometers can measure bladder pressure and acceleration

Multi-Layer embedded carbon fibers as highly compliant and stretchable interconnects

This paper describes a unique technique to manufacture highly stretchable and implantable interconnects. A possible application is presented, where the interconnects are intended to create a network of nodes sensing biological parameters in e.g. the bladder wall. The interconnects are fabricated by embedding nickel-plated carbon fibres bundles first in a thin polyurethane tube and then in a soft, elastic, polydimethylsiloxane matrix. The insulation barrier properties of the proposed packaging technique were verified by a leakage current measurement performed in body mimicking media. The use of multiple thin fibres increases the amount of bending cycles before mechanical failure occurs. Carbon fibres possess extraordinary fatigue resistance and can withstand more than 160,000 deformation cycles under normal operating conditions without failing and displaying minimal impedance change. Patterning the polymeric matrix in a meander shape, along with the conductors, allowed to fabricate extremely compliant interconnects that can achieve large deformations in response to low tensile stress. Due to the carbon fibres strength, the only factor limiting the device's ultimate elongation is the geometrical length of the meandering structure itself. Even when stretched to its maximum, beyond normal operating conditions, the completely assembled device survived 20,000 loading cycles before failure of the polymeric coating. The proposed interconnects can follow the extensive deformation of the biological structures they are attached to, without mechanically loading the biological tissue.status: publishe

I sistemi fortificati integrati tra Epiro, Sicilia e Magna Grecia in Età ellenistica. Alcune note preliminari

In the research on Greek fortifications, the traditional approach applied in the past has been addressed to mere polyorcetic considerations, neglecting their relevance in the management of the settlement systems within the territorial states of the Hellenistic Mediterranean. The application of a landscape approach to urban and rural fortifications analysis in chosen study area of central Mediterranean (Albania, southern Italy, Sicily) allows us to understand their multifaceted functions within the political, cultural and military system of Hellenistic kingdoms, and their relationship to the organization of rural production and viability

SVILUPPO URBANISTICO, FORTIFICAZIONI E VIABILITÀ NELL’EPIRO ELLENISTICO: IL CASO DELLA VALLE DEL FIUME VJOSA (ALBANIA MERIDIONALE)

The paper seeks to present some highlights on the landscape of Hellenistic Epirus on the basis of the re‐ search carried out in Byllis and in its surrounding area, i.e. the valley of the river Vjosa (southern Albania). The local settlement system is still closely linked to the rough orography engraved by the course of the Vjosa river: the environmental characteristics of this sector of Albania and its position between the Adriatic Sea and the northern Greece have significantly affected the development of the local landscape throughout antiquity. Indeed, thoughout the fourth‐third centuries BC, the region was embedded within the hellenistic kingdoms: the study of urban and rural fortifications and the contextual analysis of settlement system and roads allow to highlight the characteristics of the pervasive organization planned by the Hellenistic basileia, whose traces are still deeply impressed in the contemporary landscape