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Green Enterprise Workersâ Participation in Social Change induced by Climate Discourses: Institutionalization of the global policy clubsâ green discourses at the local level
No full textThis dissertation explores the development of a human capital concept that is here referred to as "Âgreen footprint competence" among workers and members of organizations that position themselves as "Âgreen"ÂÂ, "Âorganic"ÂÂ, or "Âenvironmental solutions providers"ÂÂ. The research contributes to the studies of social and environmental change by analysing three aspects of this change: a) the institutionalisation of the global green and low-carbon discourses as values, norms, and discursive practices within organizations in Kyrgyzstan and China; b) the emergence of the green organizational identity; c) and the development of the new competences for the climate change adaptation and mitigation along with the "Âgreen identity" of workers and members of greening organizations. The key argument formed as a result of this research is that the development of standards for measuring and reporting of the Personal and Organizational consumption of Earth Resources (i.e.,. personal and organizational carbon and/or ecological footprints), requires a more democratic and inherently more participative approach through developing green competences of organizations workers
On-chip photonic label-free biosensors
No full textThe development of a highly integrated optical biosensor
is expected to significantly impact on the performances and on the throughput of biochemical assays, with applications in the field of pharmaceutical research, point-of-care diagnostic, food-borne pathogens screening and safety.
This dissertation studies the development of a label-free
on-chip biosensor for the selective detection of Aflatoxin-M1 from milk content. We detail the design and the realization of two types of multiplexed sensors. They are based on the silicon photonics technology and operates in liquid ambient at wavelengths in the near-visible and near-infrared spectra. Most of this work is focused on the first type of sensor,which is based on a whispering-gallery-mode resonator. In particular, we analyze microdisk, microring and wedge resonator structures, studying the sensitivity and the quality factor of each. The appeal of these structure is given by the low detection limit that can be achieved in a footprint of few tens of microns per side.
The second sensor type is based on a spectrally resolved
asymmetric Mach-Zehnder interferometer. In this case, the
high level of folding permitted by the use of high refractive-index-contrast materials enables the fabrication of sensitive interferometers in a reasonable footprint.
The experimental characterization of the bulk refractometric sensing of the devices is performed in continuous flow, using a dedicated microfluidic flow-cell in PDMS. This characterization assesses the high resolution of both device types, which are able to resolve variations in the refractive index of the liquids with a limit of detection down to 10^-6 refractive index units (RIU).
The selective superficial sensing is also evaluated, implementing a biorecognition functional layer with DNA-aptamers. The assay of buffered solutions containing Aflatoxin-M1 molecules confirms that the devices under test are suitable biosensors, with specific detection limits down to about 100 pg/ml for the Mach-Zehnder interferometer, and slightly larger for the microring resonator.
A procedure for the regeneration of the sensor has been
optimized, enabling reproducible sensing up to nine times. The detection of the receptor-ligand binding in real-time enabled the study of the kinetics of the binding reaction, and we measured for the first time the kinetic rate constants of the antiaflatoxin aptamers of our sensors
Multi-target tracking in unevenly illuminated scenes
No full textVisual tracking under non-uniform illumination is challenging as the appearance of a target may change across the scene, while it is being tracked. To account for this, a built-in color correction can be used to transform local
tracking observations into a globally normalized color space, hereby compensating for the uneven illumination affecting the tracking. In a static environment a parametric model of such correction can be calibrated to the scene illumination off-line, by using a color chart, but in practical applications this may not be feasible. In this research we present methods to obtain such correction without requiring a calibration pattern be placed in the environment, instead, we use observations of people moving around in the scene as illumination probes naturally collected with a detector. The learning is always carried out in an unsupervised manner with different methods, and
in the final part of the of this research we proposed a data association step to group detections into tracklets, and the color correction parameters are then found by optimizing appearance similarity within tracklets. Reported
experiments for each method show that our methods are able to effectively learn the color correction with multiple people to achieve robust tracking in unevenly illuminated scene
The World Is Broken: The Social Construction of a Global Corruption Problem
Get PDFThis thesis examines the social construction of a global corruption problem by introducing a methodological framework from the field of sociology and adapting it to International Relations (IR). It provides an alternative explanation for the adoption of anti-corruption instruments in the period 1994-1997 and the international institutionalization of anti-corruption reforms. It challenges conventional views that point to the rise of non-state actors, such as Transparency International, and the end of the Cold War. By tracing the trajectory of the corruption problem, it shows that the dynamics of the 1990s can only be fully understood within the legacy of the 1970s and, in particular, the failed talks at the United Nations. The institutionalization of the global corruption problem in the 1990s was a product largely of historical contingency and state intentionality. While it appeared that a new issue has taken international organizations by storm, it was largely key state agents that were creating this change by building coalitions and maneuvering between venues. The thesis employs methods of discourse and practice analysis from sociological research for the empirical study of claims. The analysis makes use of archival data to open up the pre-negotiation talks on illicit/corrupt payments at the OECD and the UN and study the process of claims-making, as well as document discursive strategies such as controversy management and feasibility. By taking a step back from the study of norms to look at the social construction of problems, the thesis introduces new methodological tools into constructivist IR. It also provides for the integration of state agency in constructivist approaches by showing how state actors engage in ontological warfare over the definition and institutionalization of new problems. Studying the social construction of problems through the process of claims-making elucidates the power relations that inform the established definitions and the spectrum of legitimate solutions; it helps us better understand the makings of international reality
Measuring directed functional connectivity in mouse fMRI networks using Granger Causality
No full textResting-state functional magnetic resonance imaging (rsfMRI) of the mouse brain has revealed the presence of robust functional connectivity networks, including an antero-posterior system reminiscent of the human default network (DMN) and correlations between anterior insular and cingulate cortices recapitulating features of the human “salience network”. However, rsfMRI networks are typically identified using symmetric measurements of correlation that do not provide a description of directional information flow within individual network nodes. Recent progress has allowed the measure of directed maps of functional connectivity in the human brain, providing a novel interpretative dimension that could advance our understanding of the brains’ functional organization. Here, we used Granger Causality (GC), a measure of directed causation, to investigate the direction of information flow within mouse rsfMRI networks characterized by unidirectional (i.e. frontal-hippocampal) as well as reciprocal (e.g. DMN) underlying connectional architecture. We observed robust hippocampal-prefrontal dominant connectivity along the direction of projecting ventro-subicular neurons both at single subject and population level. Analysis of key DMN nodes revealed the presence of directed functional connectivity from temporal associative cortical regions to prefrontal and retrosplenial cortex, reminiscent of directional connectivity patterns described for the human DMN. We also found robust directional connectivity from insular to prefrontal areas. In a separate study, we reproduced the same directional connectivity fingerprints and showed that mice recapitulating a mutation associated to autism spectrum disorder exhibited reduced or altered directional connectivity.
Collectively, our results document converging directional connectivity towards retrosplenial and prefrontal cortical areas consistent with higher integrative functions subserved by these regions, and provide a first description of directional topology in resting-state connectivity networks that complements ongoing research in the macroscale organization of the mouse brain
Broadband Radio Interfaces Design for "4G and Beyond" Cellular Systems in smart urban Environments
No full textBroadband, ubiquitous and energy-efficient wireless networking is one of the pillars in the definition of a really smart urban environment. The latest developments in such a field concern with the forthcoming LTE-A standard, which will also involve small cell deployment for broadband coverage yielding increased quality of experience and reduced power consumption. Some open issues related to small cell LTE-A networking for smart city applications are discussed, together with feasible solutions that are investigated in terms of robust PHY-layer configurations, and fully-wireless backhaul (point-to-point transmission,
point-to-multipoint etc.). One such issue is related to power-constrained uplink transmission, where cooperative multipoint (CoMP) in small cell network is considered assuring better quality of service and energy efficiency for user terminal. Moreover, a novel MIMO detection is conceived for LTE-A application based on MCBEP criterion that is suited for size-constrained small base station and guaranteeing near-optimum performance. A door open to upcoming mobile standards by proposing constant envelope techniques in the uplink providing flexible tradeoff between spectral and power efficiency for 5th generation applications. A complete wireless backhaul based on millimeter wave (mmWave), for network of small cells, is considered due to its cost effectiveness and flexible operations. A robust PHY-layer waveform based on space-time MIMO techniques have proven to be the right choice for non-line of sight operations whereas TH-IR UWB techniques are providing significant data rates in line-of-sight case. SDR-Implementation of advanced wireless strategies is important in order to realize network reconfigurability in future cellular networks where network functionalities can be changed on the fly
Seismic Behaviour and Ductility Evaluation of multi-storey Light timber-frame Buildings by Means of analytical Formulations and numerical Modelling
No full textThe research activity is focused on the study of both the linear and nonlinear behaviour of light timber-frame shear-walls buildings (called Platform Frame); in the first part the analysis of the linear-elastic behaviour is presented, whereas in the second part the non-linear behaviour is considered. After a short introduction on the state of the art of timber buildings both from the constructive and from the legislative point of view, the linear-elastic behaviour of single timber shear-wall is presented. The analysis of a single timber shear-wall allows to develop an analytical equation and simplified numerical macro-model (called UniTn-Model) which are able to represent the behaviour of a wall both in terms of displacement capacity and, much more important, in terms of stiffness. In fact, the evaluation of the correct walls stiffness constitutes a fundamental step in the seismic analysis of the timber buildings.
The later section is based on what stated about the single-wall and it deals firstly with the elastic behaviour of systems composed by single-storey coupled walls and then it analyses systems of multi-storey single-walls. Theses analyses highlighted the influence of the vertical loads on the external force distribution within the shear walls, as well as the changing of the system stiffness caused by the hold-downs state variation. Both these aspects allow to develop some analytical formulations through which the stiffness matrix of full-scale buildings can be determined. Three iterative methods for the application of the Modal Response Spectrum Analysis are also presented; the differences between the methods, from the computational point of view as well as from the analytical one, are emphasized by means of a case study. The second part illustrates the non-linear analysis of a single shear-wall in order to identify the influence of the base components features on the wall ductility, both from the qualitative and the quantitative point of view; the UniTn-Model is hence extended to the non-linear field. It is also determined that the contribution of the nail deformation is not dependent on the nails spacing but it is only dependent on the geometry ratio of the sheathing-panels themselves. This property, analytically determined, is demonstrated on the basis of numerical and experimental analyses, by means of some non-linear F.E.M. analysis and some ad-hoc laboratory tests respectively. In the following section, using what developed for the single shear-wall, the non-linear analysis of single and multi-storey full-scale buildings is performed. The analyses are performed in order to assess the ductility level achievable by the buildings varying the ductility of the base components as well as the failure mechanism. In order to get generalized results and provide reliable values of ductility for the constructive system analysed, a large set of non-linear analysis has been performed through the use of a Matlab code specifically developed. This allowed to determine the ductility level that light timber-frame buildings can reach and to propose a new set of values for the behaviour factor q to be used in the seismic design.
In the last section the study of the applicability of the capacity design to the light timber-frame buildings is presented. This study assesses the conditions that make the capacity design physically feasible and economically viable in comparison to the elastic design. The analyses have been conducted by varying both the geometry of the buildings that the seismic force level
Quantum Transport of Electronic Excitations through Macromolecules
Get PDFThe investigation of real-time dynamics of charged and neutral quantum excitation propagating
through macromolecular systems is receiving growing attention due to its potentially countless
applications in nano-scale (opto-)electronics and in biophysics.
Several key issues have not been fully clarified yet, including the role played by molecular thermal fluctuations and the possible correlations between the degree of quantum coherence and the efficiency of the transport process. In order to gain some insight, we developed a rigorous and systematic framework describing quantum transport, based on a field-theoretic formalism
Modelling of Grazing Incidence X-Ray Fluorescence (GIXRF) for surface layer characterisation.
No full textGIXRF (Grazing incidence X-Ray Fluorescence) is an analytical technique with high potential in the study of depth profiles and in the characterization of thin layered structures. To extract information from a GIXRF
measurement and determine the layer composition it is necessary to compare the experimental data with simulation. However at the moment this thesis has been written, there is no software widely recognized from the scientific community as the reference software for the analysis. For this
reason this work of thesis deals with the development of an analytical software and its application to several case studies. A program called GIMPy is presented. The program is capable to perform simulations of the expected GIXRF signal from a given model, but also of the expected fluorescence signal at high angle of incidence and the reflectivity (XRR). The use of a programming language like Python makes
the library extremely portable, easily extendible and flexible thanks to its object oriented syntax and scripting capabilities. GIMPy bases the modelling of the electric field propagation inside the sample and the expected
fluorescence from the theoretical description found in literature. Moreover a series of methods were developed to account for the effect of the instrumental set-up geometry, the detector response, indirect excitation and primary beam shape and energy composition. A round-robin related
to GIXRF comparison with several institutes developing an analytical software has been organised. The comparison showed a good agreement between the results obtained with GIMPy and the other programs. GIXRF has then been applied to the characterisation of several systems. A combined XRR and GIXRF analysis of multi-layered transparent and
conductive oxide films (TCO) of technological interest resulted in a nondestructive and precise characterization of their structures. Measurements were performed at the ESRF synchrotron facility and in the laboratory using a Cu tube as source. Combining the measurements performed with dif-
ferent instrumental set-ups the effectiveness of the combined XRR-GIXRFapproach, that has proved already effective in the past, has been further shown. It has been possible to evidence the existence of a thin inter dif-
fusion profile induced by annealing the samples, showing a sensitivity to structural changes in the depth of 0.5-1 nm.
GIXRF measurements performed on Sn implants in Ge provided information about the total dose retained by the sample after an implantation process. Synchrotron tunable excitation energy was extremely valuable for the fluorescence analysis.The two different modelling strategies used for data fitting, one using a SIMS profile as an input the other an analytical description of the depth profile, and returned values close to the one obtained with other techniques. A new technology based on the deposition of ALD coatings for the preservation of cultural heritage object has been characterised with XRR and GIXRF. The XRR measurements were effective in revealing the deterioration of the coatings after the effect of an accelerated ageing process. Moreover the analysis of GIXRF also revealed the formation of nano-particles at the top of the surface, and allowed the characterisation of their size and composition.
The last chapter shows some theoretical calculations investigating GIXRF potential in the size and chemical characterisation of nano-particles. It is shown how the experimental setup and the sample preparation can influ-
ence the outcome of the measurement. The theoretical calculations are also reinforced by the result obtained on some preliminary experiments on Gold nano-particles
Supercritical Technologies for the Valorization of Wine Industry By-Products
No full textThis study aim at the valorization of wine industry by products; particularly on the extraction and characterization of grape seeds oil using supercritical CO2 (SC-CO2) and polyphenols from grape skins and defatted grape seeds using subcritical water (SW) and then, modeling of the kinetics of extractions and process economic analysis. The overall objective of the work is to develop recovery strategies for wine-making wastes in order to reduce their environmental impact and to valorize them in order to provide wine-makers with the possibility of selling by-products at a profitable price. To address the objectives, the work is divided into seven Chapters. In Chapter 1, some general overview and the fundamental of SC-CO2 and SW technologies along with emerging areas of applications are presented. Special emphasis is given to the work in the field of valorization of agro-industrial by-products. Then, the Chapter ends by stating the general and specific objectives of the thesis. The second Chapter is devoted to the characterization of grape seeds oil. To make the result more holistic, grape seeds from six grape cultivars were extracted using SC-CO2 in two subsequent harvesting years and the resulting oils were characterized. Comparative extractions were also performed by utilizing conventional solvent extraction using n-hexane and by mechanical press. The results testify the potentiality of grape seed oil as a source of unsaturated fatty acids and tocols. Moreover, they offers a clear picture of the similarities and differences among oils from different grape cultivars and obtained through different extraction techniques. The third Chapter is dedicated to compare the effectiveness of the models used to evaluate the kinetic of SC-CO2 extraction curves. Particularly, three models, the broken and intact cells (BIC), the shrinking core (SC), and the bridge (combined BIC-SC) models are critically analyzed. The objective of the Chapter is to objectively choose the best model that can be used in the subsequent Chapters. In order to model the kinetics of SC-CO2 extraction, one of the very important parameter is the solute solubility. But solubility data (especially of grape seed oil) is very scares in the literature. The bulk majority of the scientific works estimate the value of solubility of solute in SC-CO2 from theoretical models. So, the fourth Chapter is devoted to experimental determination of solubility of grape seed oil in SC-CO2 over a range of pressure and temperature of practical importance and the data were modeled by different models to compare their effectiveness. The fifth Chapter is aimed to study the effect of the main process variables affecting the SC-CO2 extraction of oil from grape seeds, both experimentally and through modeling. The dependency of the extraction kinetics on the variables more tested in the literature (pressure, temperature, particle size and solvent flow rate) was confirmed, and original trends were obtained for the less investigated variables, such as the bed porosity (ε), the extractor diameter to length ratio (D/L), the extractor free volume and the type of cultivars.
In the sixth Chapter the attention is moved to the valorization of grape skins and defatted grape seeds by using SW. The results show that, both skins and defatted seeds contain significant concentration of polyphenols and SW is a potential green solvent for extracting valuable polyphenols from wine-making by-products. The extraction kinetics was also simulated by a simple model available in the literature. In the seventh and last Chapter, a preliminary economic feasibility study was investigated for the establishment of SC-CO2 extraction plant for the extraction of grape seeds oil. The result shows that, a SC-CO2 extraction plant is technically viable and economically feasible for the extraction of grape seed oil with estimated rate of return on investment at 8.5% and payback period of 5 year at current minimum retail selling price of grape seed oil in the market. The project has an attractive socio-economic and environmental benefit and generates substantial revenue for the local government in the form of tax and will allow wine-makers to sell wet grape marc at a price of up to US$ 10/ton