Electrophysiological and behavioral characterization of parent-of-origin effects in mice

Caratterizzazione comportamentale ed elettrofisiologica dell'effetto parentale nei top

What the water says as it runs

During the last two years, I have been examining the importance of vulnerability, memory and empowerment within my work as it relates to archival silence. The archive is presumed to be an objective record but what is chosen and discarded is an inherently political act. When there is archival silence, what then becomes missing from our collective histories? My exploration has spread across many forms of media, including sound, video, textiles, sculpture and writing . I have sought to understand the ways that these different mediums embody sentiment and concept, while establishing an open-ended record within which others can explore their own personal context. Archival silence is often perpetuated by discrimination and untold traumatic narratives. What then happens when we create records of these excluded or unspoken narratives, when we express vulnerability? Might we reach a point of collective empowerment? Through this work, I have found that negotiating between different mediums has allowed me to create a context for myself and explore deeply personal subjects, while simultaneously creating work and records that will resonate with those who pay close enough attention. I have done this by using video and sound recordings of places that are the architectures of my memory, building an installation that replicates a location very formative to me and my memory, and – perhaps most importantly – writing that presents my memory fragments as they are retrieved. These architectures are intentionally abstracted through a spectrum of mediums, creating a container into which the audience is enabled to project their own memories and identities. My personal record reaches towards justice by presenting vulnerable stories with which others may be able to identify. If this work does anything, I hope that it prompts my viewers to reflect on their own experiences, and to orient themselves to a future in which they don’t feel as though sharing a difficult experience is impossible. Through that process, I believe that we can move our record keeping towards justice

Evaluation of porosity and degree of saturation from seismic and electrical data

The characterisation of unsaturated intermediate and coarse-grained soils faces some practical difficulties because undisturbed sampling is not easy. Geophysical methods provide useful information as they can be applied on site for testing geo-materials in their natural state. Moreover their repeated application over time is effective and efficient for monitoring purposes. A procedure for evaluating porosity and degree of saturation on the basis of electrical resistivity and wave velocities measurements is proposed. The approach is based on an electro-seismic model that utilises Archie's law to describe the electrical behaviour of soils and a recent formulation of elastic wave propagation in unsaturated soils. The proposed procedure is applied to laboratory data, and shows promising result

An efficient composite membrane to improve the performance of PEM reversible fuel cells

The aim of this study is to develop composite Nafion/GO membranes, varying GO loading, to be used in a Unitized reversible fuel cell comparing its performance with the baseline Nafion. Water uptake, ion exchange capacity (IEC), tensile strength, and SEM (scanning electron microscope) analysis are discussed. The SEM analysis revealed how the GO is homogeneously disposed into the Nafion matrix. The addition of GO improves the membrane tensile strength while reducing the elongation ratio. Water uptake, IEC enhance with the increasing of GO content. Regarding fuel cell mode, the performance is analysed using a polarization curve on a MEA with an effective area of 9 cm2. The composite membrane demonstrated higher mechanical strength, enhanced water uptake so higher performance in fuel cell mode. Despite the power absorbed from the electrolysis is higher when using a composite membrane, the beneficial effect in FC mode resulted in a slightly higher round trip efficiency. The GO-Nafion membrane was not able to maintain its performance with increasing the operating time, so potentially leading to a lower lifetime than the Nafion bare

Effects of 2012 Earthquake on the behavior of Ghirlandina tower in Modena

Collapse events, that occurred in the past (such as the Venice Bell Tower in 1902 and the Civic Tower in Pavia in 1989) claimed for the need to assess the long-term behavior of such monuments. A significant effort has been therefore devoted to clarify the reasons for these collapses after many centuries from the construction date. In addition, recent earthquakes in Italy have once again put into evidence the seismic vulnerability of the cultural heritage. To assess this aspect, in many cases the soil-structure interaction cannot be neglected. In this context, a simple but consistent framework for soil-structure interaction analysis is here presented with reference to a case history. It is discussed how the difference in the fundamental frequency observed during seismic events can be associated to non-linearity in soil response, leading to a rotational stiffness of the soil-foundation system consistent with the shear strain level derived from the seismic ground response analysis. Thereafter, the validated soil-structure interaction model has been used to define an equivalent SDOF model of the structure that explains the differential settlements suffered by the Ghirlandina tower in Modena during the 2012 seismic events as well as its behavior since those events

Experimental evidence and prediction of soil-structure interaction effects for a masonry tower

Remedial actions on historical buildings have to be planned carefully in order to preserve not only the shape and appearance of the monument but also its historical and material integrity. This requires a deep knowledge of the behaviour of the structure, based on long term observations, and quite often the interaction with soil plays a relevant role. In particular, this interaction cannot be neglected when dealing when assessing both seismic vulnerability and long-term behaviour. Although advanced numerical tools are increasingly available, simple approaches still play a fundamental role for the understanding of the actual behaviour of complex structural systems in the engineering practice. In this work a rational framework for soil-structure interaction analysis is proposed and validated by using experimental data from a permanent monitoring system installed on a masonry tower in Italy

Assessment of the structural representativeness of sample data sets for the mechanical characterization of deep formations.

Accurate characterization of the mechanical behavior of geomaterials at depth is a fundamental need for geologic and engineering purposes. Laboratory tests on samples from well cores provide the material characterization in terms of mechanical response and other relevant properties. Representativeness of a sample data set with respect to the in situ conditions at depth is a key issue, which needs to be addressed to extrapolate the laboratory response to the whole rock mass. We have developed a procedure aimed at quantitatively evaluating the representativeness of laboratory samples. The methodology is based on joint processing of laboratory ultrasonic tests and wellbore sonic logs. A structural index is used to quantify the difference between the average structure of the laboratory sample and the structure of the formation at the wellbore scale. This index could be used to identify different causes of discrepancies between the behavior of the cored samples and the behavior of the rock formation as documented by well logs. Then, it could also be used to integrate laboratory data for the construction of a reliable geomechanical model with reference to the real in situ state. The methodology was applied to three different experimental data sets, showing the effectiveness of the method

Preliminary investigation on the water retention behaviour of cement bentonite mixtures

Cement bentonite mixtures are often used to build slurry walls for the containment of both aqueous and non aqueous pollutants, due to their quite low hydraulic conductivity and relatively high ductility and strength. Although their hydro-mechanical behaviour in saturated conditions has been studied in the past, a part of the slurry wall is expected to rest above the groundwater level. The hydraulic characterization in unsaturated conditions is then particularly relevant to evaluate the performance of the barrier, especially when it is aimed at containing non aqueous pollutant liquids which are lighter than water (LNAPL). These non wetting fluids rest above the water table and their penetration is possible just if the barrier is unsaturated. This paper presents some preliminary results of a laboratory characterization of the water retention behaviour of three different cement bentonite mixtures. The mixtures, prepared at cement - bentonite mass ratios ranging from 4:1 to 6:1, were immersed in water and cured for 28 days. Their water retention behaviour was then determined along drying and wetting paths through different techniques, namely axis translation, filter paper and vapour equilibrium. In the high suction range, the water content - suction relationship was found to be independent of cement-bentonite ratio. In the low suction range, the water content at a given suction was found to decrease for increasing cement bentonite ratios