Timelapse ultrasonic tomography for measuring damage localization in geomechanics laboratory tests.

Variation of mechanical properties in materials can be detected non-destructively using ultrasonic measurements. In particular, changes in elastic wave velocity can occur due to damage, i.e., micro-cracking and particles debonding. Here the challenge of characterizing damage in geomaterials, i.e., rocks and soils, is addressed. Geomaterials are naturally heterogeneous media in which the deformation can localize, so that few measurements of acoustic velocity across the sample are not sufficient to capture the heterogeneities. Therefore, an ultrasonic tomography procedure has been implemented to map the spatial and temporal variations in propagation velocity, which provides information on the damage process. Moreover, double beamforming has been successfully applied to identify and isolate multiple arrivals that are caused by strong heterogeneities (natural or induced by the deformation process). The applicability of the developed experimental technique to laboratory geomechanics testing is illustrated using data acquired on a sample of natural rock before and after being deformed under triaxial compression. The approach is then validated and extended to time-lapse monitoring using data acquired during plane strain compression of a sample including a well defined layer with different mechanical properties than the matrix

Effetto della suzione e tensione di confinamento sulla resistenza a taglio di una miscela sabbio-limosa costipata

La presente nota illustra sinteticamente le fasi di esecuzione e le modalità interpretative di prove triassiali consolidate drenate (TXCD) condotte su una miscela di sabbia e limo argilloso costipata in condizioni di parziale saturazione. I test a controllo di suzione sono stati eseguiti mediante un’apparecchiatura triassiale a doppia parete, il cui piedistallo è stato equipaggiato con una pietra porosa a elevato valore di ingresso d’aria, al fine di prevenire il fenomeno di cavitazione all’interno delle linee di drenaggio. Nel corso delle prove la suzione target è stata imposta attraverso la tecnica della traslazione degli assi e la variazione di volume dei provini stimata mediante un dispositivo cilindrico a doppia camera, in grado di correlare tali modificazioni alle letture di un sensore di spostamento induttivo (LVDT). I risultati della campagna di indagine, comparati ai corrispettivi ottenuti da prove effettuate in condizioni sature, evidenziano che la suzione contribuisca in maniera significativa alla resistenza a taglio dei terreni e che il suo effetto vari in maniera non lineare in funzione del grado di saturazione e della tensione di confinamento

Centrifuge modelling of the behaviour of pile groups under vertical eccentric load

Annular shaped pile groups are a very common foundation layout for onshore wind turbines and other slender structures. In this study, their performance under vertical loads of moderate to high eccentricity, including moment rotation response and bearing capacity, was investigated by centrifuge testing on small scale physical models embedded in kaolin clay. To identify experimentally the capacity of the examined pile groups under different load paths, the model foundations were loaded monotonically until a clear collapse mechanism was achieved. The testing procedure and the proposed interpretation methodology can be easily adapted to load paths or pile layouts other than those considered in the current study. The experimental data can be adopted as a useful benchmark for mathematical models aimed at predicting the response of pile groups to complex load paths. The results of this testing program can also be used to assess the degree of conservatism of current methods adopted by industry for the design of piled foundations subjected to eccentric loads

Exploring concepts of health with male prisoners in three category-C English prisons

Lay understandings of health and illness have a well established track record and a plethora of research now exists which has examined these issues. However, there is a dearth of research which has examined the perspectives of those who are imprisoned. This paper attempts to address this research gap. The paper is timely given that calls have been made to examine lay perspectives in different geographical locations and a need to re-examine health promotion approaches in prison settings. Qualitative data from thirty-six male sentenced prisoners from three prisons in England were collected. The data was analysed in accordance with Attride-Stirling's (2001) thematic network approach. Although the men's perceptions of health were broadly similar to the general population, some interesting findings emerged which were directly related to prison life and its associated structures. These included access to the outdoors and time out of their prison cell, as well as maintaining relationships with family members through visits. The paper proposes that prisoners' lay views should be given higher priority given that prison health has traditionally been associated with medical treatment and the bio-medical paradigm more generally. It also suggests that in order to fulfil the World Health Organization's (WHO) vision of viewing prisons as health promoting settings, lay views should be recognised to shape future health promotion policy and practice

Metabolic characterization of Palatinate German white wines according to sensory attributes, varieties, and vintages using NMR spectroscopy and multivariate data analyses

1H NMR (nuclear magnetic resonance spectroscopy) has been used for metabolomic analysis of ‘Riesling’ and ‘Mueller-Thurgau’ white wines from the German Palatinate region. Diverse two-dimensional NMR techniques have been applied for the identification of metabolites, including phenolics. It is shown that sensory analysis correlates with NMR-based metabolic profiles of wine. 1H NMR data in combination with multivariate data analysis methods, like principal component analysis (PCA), partial least squares projections to latent structures (PLS), and bidirectional orthogonal projections to latent structures (O2PLS) analysis, were employed in an attempt to identify the metabolites responsible for the taste of wine, using a non-targeted approach. The high quality wines were characterized by elevated levels of compounds like proline, 2,3-butanediol, malate, quercetin, and catechin. Characterization of wine based on type and vintage was also done using orthogonal projections to latent structures (OPLS) analysis. ‘Riesling’ wines were characterized by higher levels of catechin, caftarate, valine, proline, malate, and citrate whereas compounds like quercetin, resveratrol, gallate, leucine, threonine, succinate, and lactate, were found discriminating for ‘Mueller-Thurgau’. The wines from 2006 vintage were dominated by leucine, phenylalanine, citrate, malate, and phenolics, while valine, proline, alanine, and succinate were predominantly present in the 2007 vintage. Based on these results, it can be postulated the NMR-based metabolomics offers an easy and comprehensive analysis of wine and in combination with multivariate data analyses can be used to investigate the source of the wines and to predict certain sensory aspects of wine

Moving prison health promotion along: Towards an integrative framework for action to develop health promotion and tackle the social determinants of health

The majority of prisoners are drawn from deprived circumstances with a range of health and social needs. The current focus within ‘prison health’ does not, and cannot, given its predominant medical model, adequately address the current health and well-being needs of offenders. Adopting a social model of health is more likely to address the wide range of health issues faced by offenders and thus lead to better rehabilitation outcomes. At the same time, broader action at governmental level is required to address the social determinants of health (poverty, unemployment and educational attainment) that marginalise populations and increase the likelihood of criminal activities. Within prison, there is more that can be done to promote prisoners’ health if a move away from a solely curative, medical model is facilitated, towards a preventive perspective designed to promote positive health. Here, we use the Ottawa Charter for health promotion to frame public health and health promotion within prisons and to set out a challenging agenda that would make health a priority for everyone, not just ‘health’ staff, within the prison setting. A series of outcomes under each of the five action areas of the Charter offers a plan of action, showing how each can improve health. We also go further than the Ottawa Charter, to comment on how the values of emancipatory health promotion need to permeate prison health discourse, along with the concept of salutogenesis

Northern Ireland’s 1968 at 50: agonism and protestant perspectives on civil rights

2018 marked the fiftieth anniversary of the seminal events of Northern Ireland’s 1968: a milestone offering up an opportunity to reassess a pivotal moment in the province’s recent past. This article will argue that the civil rights period has fitted into a common model of the past being used to perpetuate the divisions at the heart of Northern Irish society. It will go on to demonstrate how an innovative methodological and theoretical approach, based on oral history, education and – most crucially – agonism, has facilitated the unearthing and integration of complex and hitherto marginalised Ulster Protestant perspectives