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Mayr Hayastan Im Hairenik: Memory and the Politics of Construction of the Armenian Homeland
No full textEstablishment of the independent Republic of Armenia in 1991 has been a turning point in the Armenian history; except for the existence of an independent Armenian republic between 1918 and 1920, by the dissolution of the USSR, Armenians gained an independent state after more than six hundred years. The transition of the Soviet Armenia to an independent republic stimulated not only the radical dislocation of the established economic, political and socio-cultural structures in Armenia, but also transformed the routine in the Armenian diaspora communities. In this process, aiding the frail and infant independent Armenian republic became a paramount ethno-national cause among the diaspora communities and, by extension, one of the principal ethno-national binders, as well as a chief cause of controversies. Overall, the post-1991 era has witnessed the re-territorialization of the de-territorialized Armenian political imagination in the diaspora. This facilitated the post-1991 trans-state Armenian ethno-national re-construction along the Armenia-diaspora nexus. A parallel process to that has been the construction of the social reality of the post-1991 Armenia. This dissertation examines the construction of the Armenian ethno-national social reality of the post-1991 Armenia through the discursive social practices of the Armenian state, new generation diaspora organizations and the diasporic individuals within the communicative space formed along the Armenia-diaspora nexus. The examination demonstrates that concerns over the physical and cultural survival of the Armenian ethno-nation expressed in different ways are the main considerations that eventually result in the construction of the post-1991 Armenia as the guardian and the soil of the Armenianness. From an abstract point of view, the actual agent of discourses that speaks through the Armenian state, new generation diaspora organizations and the diasporic individuals is the “anxious Armenian” who searches stability and security, reclaims her ethno-national identity, and is concerned about the cultural survival of the Armenian ethno-nation. Besides all, she is the one who “remembers” the genocide. This “anxious Armenian”, instead, is the person that the social memory of the genocide speaks itself through. As such, genocide is not only the “defining and founding moment” of the contemporary Armenian identity, but also the “defining and founding moment” of the post-1991 Armenia
Materials Development for the Fabrication of Metal-Supported Solid Oxide Fuel Cells by Co-sintering
No full textSolid Oxide Fuel Cell (SOFC) is an upcoming technology seen with great expectations for the production of electrical energy with good efficiency and minimal environmental impact. Successful commercialization of SOFCs has however been hindered despite the optimistic promises made by some developers. This slackened commercialization of SOFCs technology is mainly due to the high cost associated with SOFC production and its limited long term stability. The long term stability of conventional Anode Supported-Solid Oxide Fuel Cell (AS-SOFC) with Ni based anode is tested by its limited tolerance towards redox cycling and rapid thermal cycling.
The introduction of new generation SOFC, the so called Metal Supported- Solid Oxide Fuel Cell (MS-SOFC) has shown to overcome the drawbacks associated with the conventional AS-SOFC. Thus, MS-SOFC is looked upon as the potential candidate for the rapid commercialization of SOFC technology. In MS-SOFC design, the cell is supported on a porous metal substrate instead of expensive and non-reliable anode as in AS-SOFC. In this design the thickness of the functional layers (anode, cathode and electrolyte) is kept thin as possible (in the order of 10-50m) just necessary for electrochemical activities while the support being provided by the metal substrate.
Although MS-SOFC can be fabricated by different routes, co-sintering of metal/anode/electrolyte multilayers in non-oxidizing atmosphere at high temperatures (1300 to 1400oC) is the most promising as far cost efficiency and industrial scale up is concerned. The cathode is usually applied after high temperature processes and sintered in situ during operation in this route. This fabrication approach however has some drawbacks associated with it. This work is basically on the development of materials and optimization of the multilayer design for the production of MS-SOFC by cost-effective co-sintering approach. YSZ (Y2O3 stabilized ZrO2), Ni-YSZ cermet, and ferritic stainless steel are considered for the electrolyte, anode and the support respectively. The anode and electrolyte were modified with the help of suitable dopants and the multilayer design was also altered in order to facilitate the co-sintering, preventing or reducing the generally encountered issues in this fabrication route.
Coarsening of Ni in Ni-YSZ anode cermet and over-sintering of anode during high temperature co-sintering is a well-known issue. Ni coarsening reduces the number of triple phase boundaries (TPB) thereby affecting electrochemical performance. The electrical conductivity of the anode also degrades due to Ni coarsening. In current work, the effect of Al doping on Ni-YSZ anode sintering in Metal Supported-Solid Oxide Fuel Cell (MS-SOFC) was studied. It was found that, the addition of Al into the anode accounts for a finer microstructure if compared to undoped Ni-YSZ anode material. The electrical conductivity of the Al-doped anode was also found to increase considerabely and such result may be attributed to the fine microstructure caused by the segragation of Al2O3 formed during the course of sintering on the grain boundaries of both Ni and YSZ, thus inhibiting the sintering. 5wt% Al-doped NiO used for Ni-YSZ anode material gave the finest microstucture and the highest electrical conductivity at room temperature although it showed the lowest bulk density. Overall, Al-doped Ni-YSZ anode material was found to be a suitable material for the anode in MS-SOFC produced by co-sintering.
The modification of the reduction kinetic of NiO and the interaction between the anode and steel during the fabrication of Metal Supported Solid Oxide Fuel Cells (MS-SOFC) is also studied in the present work. With the aim to limit NiO reduction under inert atmosphere at high temperature, doping elements such as Al and Ce were considered for NiO powders modification and anode production. In order to simulate the reactions at the metal/anode interface, NiO/YSZ/steel composites were prepared with pure and Al-doped NiO. A sudden volume expansion above 10000C followed by substantial shrinkage above 12000C was observed for the composites when sintered in Ar at 14000C. Such volume expansion can be related to the oxidation of steel due to the RedOx reaction between NiO and steel. Moreover, it was found that the volume expansion, i.e. the steel oxidation, can be minimized to a good extent when Al-doped NiO is used. Hence it is proposed that Al-doped NiO is a promising candidate material to be used for anodes in high temperature sintering of MS-SOFC.
Other problems encountered during co-sintering of multilayers for MS-SOFC include delamination, cracking, bending, and interdiffusion of Fe,Cr and Ni between anode and the substrate. In another section of work, green multilayers were produced by tape-casting for the fabrication of MS-SOFC half-cell by co-sintering. The binder loss step during co-sintering was optimized so as to prevent the cracking of the multilayers due to the binder loss events. Intermediate layers (layer between metal support and rest of the layers) composed of metal-ceramic powder composite were also investigated to prevent delamination and to inhibit interdiffusion of the elements.CeO2-steel, YSZ-steel, and LDC(La doped Ceria)-steel powder composites were considered for investigation to use as intermediate layer. Out of the different multilayer design considered for investigation, YSZ/(Al-NiO)-YSZ/LDC-steel/steel multilayer design was found to be a good compromise so as to give a half-cell, with good bonding between the layers, which is camber free, and with moderate interdiffusion of elements between the substrate and the anode. It was however found in all the designs that complete densification of YSZ electrolyte could not be obtained.
In order to address the issue of limited densification of YSZ electrolyte during co-sintering, Fe was considered for doping YSZ. A comparative study was done on Fe doped YSZ samples for sintering in air and argon atmosphere, with the aim to analyze the effect of Fe as sintering aid under MS-SOFC fabrication by co-sintering conditions. Samples showed enhanced densification with increasing Fe concentration in both the sintering atmospheres thus concluding that Fe can be used as a sintering aid for YSZ even in argon. The samples sintered in argon atmosphere were however characterized by larger lattice parameter, density and grain size. The increase in lattice parameter can be attributed to the oxygen vacancies generated under low p(O2) in argon atmosphere. The microstructural analysis of the samples showed the presence of small amount of secondary phase, and the concentration of such phase was seen to be higher in the argon sintered samples. Comparison of colors of argon and air sintered samples indicates the reduction and/or precipitation of Fe dopant in samples sintered in argon. Gas tight dense electrolyte could be obtained for MS-SOFC fabricated by co-sintering when Fe doped YSZ is employed for electrolyte, although the performance of the cell was quite poor
Age-Diversity and Inclusion at the Workplace: Implicit and Explicit Attitudes, Personality and Fit
No full textThe world’s population is changing rapidly. At the same time older workers are encouraged to continue being professionally active and younger workers face postponed and precarious entry to the world of work. Moreover, there is a growing problem of generational division (e.g., Shore, 2008) and skills shortage (Hertel, van der Heijden, de Lange, & Deller, 2013). Therefore, contemporary policy makers, companies and workers are facing a challenge of building a long-term productive and engaged age-diverse workforce. One way of adressing this issue is studying factors that contribute to age-neutral vs. age-biased evaluations in selection (paper 1) and job performance evaluations (paper 2) or studying the joint effects of age and working environment on work engagement (paper 3). Specifically, paper 1 investigated effects of rater overt-explicit age bias and covert-implicit age bias towards both older to younger workers on resume evaluations of applicants in different age. Paper 2, examined effects of rater conscientiousness on the performance evaluations of younger and older “typical” worker (Study 1) and an actual coworker (Study 2). Third paper, tested the effects of age on the relation between person-environment fit and work engagement
Bio-morphodynamics of evolving river meander bends from remote sensing, field observations and mathematical modelling
No full textInteractions between fluvial processes and vegetation along the natural channel margins have been shown to be fundamental in determining meandering rivers development. By colonizing exposed sediments, riparian trees increase erosion resistance and stabilize fluvial sediment transport
through their root systems, while during a flood event the above-ground biomass interacts with the water flow inducing sediment deposition and altering scour patterns. In turn river dynamics and hydrology influence vegetative biomass growth, affecting the spatial distribution of vegetation. These bio-morphological dynamics have been observed to direct control accretion and degradation rates of the meander bend. In particular, vegetation encroachments within the point bar (i.e. colonizing species and strand wood), initiate pioneeristic landforms that, when evolving, determine the lateral shifting of the margin that separates active channel from river floodplain and thus inner bank aggradation (bar push). This diminishes the portion of the morphologically active channel cross-section, influencing the erosion of the cutting bank and promoting channel widen-
ing (bank pull ). As a result of the cyclical occurrence of these erosional and depositional processes, meandering rivers floodplain show a typical ridge and swale pattern characterized by the presence of complex morphological structures, namely, benches, scrolls and chutes within the new-created floodplain. Moreover, difference in migration rate between the two banks have been observed to induce local temporal variations in channel width that affect river channel morphodynamics and its overall planform through their influence on the local flow field and channel bed morphology. Despite enormous advances in field and laboratory techniques and modelling development of the last decades, little is known about the relation between floodplain patterns and their controlling bio-morphological
interactions that determine the bank accretion process. This knowledge gap has so far limited the development of physically-based models for the evolution of meandering rivers able to describe the lateral migration of banklines separately. Most existing meander migration models are indeed based on the hypothesis of constant channel width.
Starting from this knowledge gap, the present doctoral research has aimed to provide more insight in the mutual interactions among flow, sediment transport and riparian vegetation dynamics in advancing banks of meandering rivers. In order to achieve its aims, the research has been
designed as an integration of remote sensing and in-situ field observations with a mathematical modelling approach to i) provide a quantitative description of vegetation and floodplain channel topography patterns in advancing meanders bend and to ii) explore the key control factors and their role in generating the observed patterns. The structure of the present PhD work is based on four main elements. First, two types of airborne historical data (air photographs and Lidar survey) have been investigated, in order to quantify the effects of spatial-temporal evolution of vegetation pattern on meander morphology and to provide evidence for the influence of vegetation within the topography of the present floodplain. Such remote sensing analysis has highlighted a strong correspondence between riparian canopy structure and geomorphological patterns within the floodplain area: this has clearly shown the need to interpret the final river morphology as the result of a two-way interaction between riparian vegetation dynamics and river processes. Second, field measurments have been conducted on a dynamic meander bend of the lower reach of the Tagliamento River, Italy, with the initial aim of checking the outcomes of the remote sensing analysis through ground data. The outcomes of the field measurements have further supported the results, providing ground evidence on the relations between vegetation and topographic patterns within the transition zone that is intermediate between the active channel bed and the vegetated portion of the accreting floodplain. The influence of vegetation on inner bank morphology has also been interpreted in the light of the expected time scales of inundation and geomorphic dynamics that characterize the advancing process of the inner bank. The combined analysis of both remotely sensed data and field measurements associated with the historical hydrological dataset have allowed to quantitatively characterize the biophysical characteristics of the buffer zone, close to the river edge, where the accretion processes take place. The third research element has foreseen the development of a biophysically-based, simplified bio-morphodynamic model for the lateral migration of a meander bend that took advantage of the empirical knowledge gained in the analysis of field data. The model links a minimalist approach that includes biophysically-based relationships to describe the interaction between riparian vegetation and river hydromorphodynamic processes, and employs a non linear mathematical model to describe the morphodynamics of meander channel bed. Model application has allowed to reproduce the spatial oscillations of vegetation biomass density and ground morphology observed in the previous analyses. Overall, the model allows to understand the role of the main controlling factors for the ground and vegetation patterns that characterize the advancing river bank and to investigate the temporal dynamics of the morphologically active channel width, providing insights into the bank pull and bar push phenomena. The fourth and concluding element of the present PhD research is a analytical investigation of the fundamental role of unsteadiness on the morphodynamic response of the river channel. Results obtained in the previous elements have clearly showed the tendency of a meander bend to develop temporal oscillations of the active channel width during its evolution, but no predictive analytical tool was previously available to investigate the channel bed response to such non-stationary planform dynamics. A non linear model has therefore been proposed to investigate the effect of active channel width unsteadiness on channel bed morphology. The basic case of free bar instability in a straight channel has been used in this first investigation, which has shown the tendency of channel widening to increase river bed instability compared to the steady case, in qualitative agreement with experimental observations. Overall, the research conducted within the present Doctoral Thesis represents a step forward in understanding the bio-morphodynamics of meandering rivers that can help the development of a complete bio-morphodynamic model for meandering rivers evolution, able to provide support for sustainable river management
La teoresi in Nicolás Gómez Dávila. Prolegomeni allo studio di un classico
No full textUno studio teoretico che, sviluppandosi attraverso la lettura puntuale dell'opera gomezdaviliana, consente di mostrare l'appropriata collocazione dell'autore nel firmamento della più alta filosofia di tutti i tempi
Mathematical modelling and simulation of the human circulation with emphasis on the venous system: application to the CCSVI condition
No full textRecent advances in medical science regarding the role of the venous system in the development of neurological conditions has renewed the attention of researchers in this district of the cardiovascular system. The main goal of this thesis is to perform a theoretical study of Chronic CerebroSpinal Venous Insufficiency (CCSVI), a venous pathology that has been associated to Multiple Sclerosis. CCSVI is a condition in which main cerebral venous drainage
pathways are obstructed. Its impact in cerebral hemodynamics and its connection to Multiple Sclerosis is subject of current debate in the medical community. In order to perform a credible study of the haemodynamical aspects of CCSVI, a sufficiently accurate mathematical model
of the problem under investigation must be used. The venous system has not received the same attention as the arterial counterpart by the medical community. As a consequence, the
mathematical modeling and numerical simulation of the venous system lies far behind that of the arterial system. The venous system is a low-pressure system, formed by very thin-walled vessels, if compared to arteries, that are likely to collapse under the action of gravitational
or external forces. These properties set special requirements on the mathematical models and
numerical schemes to be used. In this thesis we present a closed-loop multi-scale mathematical model of the cardiovascular system, where medium to large arteries and veins are represented as one-dimensional (1D) vessels, whereas the heart, the pulmonary circulation, capillary beds
and intracranial pressure are modeled as lumped parameter models. A characteristic feature of our closed-loop model is the detailed description of head and neck veins. Due to the large inter-subject variability of the venous system, we perform a patient-specific characterization of
major veins of the head and neck using MRI data collected in collaboration with the Magnetic Resonance Research Facility of the Wayne State University, Detroit (USA). Computational results are carefully validated using published data for the arterial system and most regions of the venous system. For head and neck veins validation is carried out through a detailed comparison of simulation results against patient-specific Phase-Contrast MRI flow quantification data. Regarding the development of novel numerical schemes, we construct high-order accurate, robust
and efficient numerical schemes for 1D blood flow in elastic and viscoelastic vessels, as well as a solver for vessel networks. The solver is validated in the context of an in vitro network of vessels for which experimental and numerical results are available. After validation of both, the mathematical model and the numerical methodology, we use our theoretical tool to study the influence of different CCSVI patterns on cerebral hemodynamics. CCSVI patterns are defined by the medical literature as combinations of venous obstructions at different locations. Here we used two strategies. First, we take a venous configuration corresponding to a healthy control
and explore the effect of different CCSVI patterns by modifying this network. Then, we characterize our venous network with the geometry of a real CCSVI patient and compare results with the ones obtained for the healthy control. The presented model provides a powerful tool to study still unresolved aspects of cerebral blood flow physiology, as well as several venous pathologies. Furthermore, it constitutes an ideal platform for improving currently used algorithms and for integrating fundamental physiological processes, such as detailed hemodynamics,
regulatory mechanisms and transport of substances
Micro-analytical methodologies for the characterization of airborne inorganic pollutants collected on unconventional substrates
No full textThe present work regards the development of a methodology for the study of atmospheric particulate matter (PM) which is alternative to instrumental measurements. The methodology developed exploits the surfaces already present in the field as samplers of PM. In particular, conifer needles and building facades are employed to investigate different temporal ranges: conifer needles potentially retain particles circulating in the atmosphere from the recent past up to now, while building facades could retain particles from an older period up to know.
The field of application of the approach developed are the situations in which a wide territory must be monitored, eventually including remote locations, or information on past pollution scenario must be reconstructed in the absence of monitoring stations. For instance, the evaluation of the improved efficiency of off-gas abatement systems of industrial plants is a typical case of application. These pollution sources affect large areas and might have been active before regulation on air quality required constant monitoring of their emissions. Typically in such a case the methodology could assist in evaluating how large was in the past and it is nowadays the area of impact of the plant. In general, such an approach could be valuable whenever relying on instrumental measurements is cost and time consuming in terms of installing a large network of monitoring stations to study the dispersion of pollutants from a single or few sources.
To have a detailed description of the spatial distribution of pollutant particles, they are studied individually with subsequent higher magnification. Where no traces of a source are detected by scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDXS), the samples are analyzed with the higher resolution of transmission electron microscopy coupled with energy dispersive x-ray spectroscopy (TEM-EDXS) and selected area electron diffraction (SAED) in order to make sure that no smaller particles, able to travel farther from their source, are present at a certain site.
All data provided by electron microscopy analysis of particles collected by conifer needles are placed in the context of elemental concentrations measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), which is a bulk analytical technique. The same is not possible for the data on single particles present on building facades given the inorganic matrix of the substrate, especially in the case of metal oxide paints, which does not allow the bulk measurement.
Both the preparation of the samples for bulk analytical techniques and single particle analysis by electron microscopy were optimized.
For method development and evaluation, the analytical protocol was applied to estimate spatial and temporal trends of accumulation of inorganic pollutants that can be related with changes in the emissions of atmospheric pollutants by an electric arc furnace (EAF) steelmaking plant located in a test site. The benefits of combining the single particle and bulk analytical techniques emerged especially for the discrimination of the emissions from different sources
Engineering & characterization of a gfp-based biosensor for ph and chloride intracellular measurements
No full textClopHensor, a new fluorescent ratiometric GFP-based biosensor, is a powerful tool for non-invasive pH and chloride quantification in cells.
ClopHensor is a chimeric construct, with the pH- and chloride-sensing E2GFP linked to the reference red protein DsRed-monomer, whose fluorescence is used as reference signal. E2GFP dissociation constant of about 50 mM (at pH=7.3) makes it ideal for quantifying physiological chloride concentration. However, chloride affinity of E2GFP strongly depends on pH value in solution: precise chloride measurement requires also a pH measurement. By ratio-imaging technique, three different excitation wavelengths are necessary for a pH and chloride concentration estimation.
With the goal to reduce the number of excitation wavelengths required for ratio-imaging technique, in this thesis I present a detailed study of H148G-V224L-E2GFP, selected among several E2GFP-variants for its improved photophysic and spectroscopic characteristics.
H148G-V224L-E2GFP exhibits a chloride affinity and a pH sensitivity similar to ClopHensor. Its emission spectra interestingly display two distinct emission peaks at 480 nm and 520 nm after excitation at 415 nm. Importantly, fluorescence emission spectra collected at various pH values also display a clear isosbestic point at 495 nm. This property allows the innovative possibility of pH and chloride concentration determination using only two excitation wavelengths.
Moreover, while being chloride independent, the 520-to-495 (nm) ratio displays a pKa value of about 7.3, centered in the physiological pH range. These characteristics make it ideal for quantifying intracellular pH changes and chloride fluxes in physiological conditions.
Applications in living cells of this new biosensor demonstrated its usefulness for ratio-imaging analysis.
H148G-V224L-E2GFP+DsRed was successfully expressed in neuron-like cells, as proof-of-concept that ratio-imaging analysis can be performed also in neuron-like cells.
These results are very promising for H148G-V224L-E2GFP+DsRed future expression in brain neurons, where chloride plays a crucial role in neuronal activity.
Purified H148G-V224L-E2GFP was successfully uploaded in polymeric vaterite nanospheres to characterize their endocytosis pathways in cells
Professione e ordine. Per una storia dell'etica professionale
Get PDFScopo di questa ricerca è interrogarsi sulla storia del campo di problematizzazione dell'etica professionale e sulle condizioni di possibilità per il darsi di un tale campo, nella convinzione che ciò consenta di riflettere da una prospettiva critica meno usuale sulla rilevanza politica del lavoro, che funge indubbiamente - nella società occidentale contemporanea - da elemento essenziale di inclusione esplicandosi come funzione normata di produzione di identità politico-sociale. Dopo aver reso conto dell'attuale dibattito in materia di etica e deontologia professionale, dei suoi immediati antecedenti e della sua relazione di affinità rispetto al contesto socioeconomico in cui esso matura, l'attenzione si concentra pertanto su una ricostruzione storica del concetto di professione che – ragionando non tanto sul versante weberiano del Beruf quanto su quello latino della professio, con speciale riferimento alla professio census e alla tematizzazione de officiis – muove dal diritto romano e dal pensiero patristico risalendo fino all'esperienza medievale, alla trattatistica della Controriforma e al graduale emergere di un'etica professionale in senso stretto sul finire del Settecento, per provare a chiarire nei termini di “inclusione nell'ordine” quell'intreccio tra radice teologica, politica ed economica che aiuta a comprendere il rilievo che alla professione è stato via via riconosciuto sul piano etico e politico-sociale
Organizational transparency: Stakeholder relationships and internal dynamics
No full textThis study examines the notion of organizational transparency through the lenses of stakeholder theory and focuses on the interaction between management and internal stakeholders. A theory-driven measure of transparency is
developed and dened along three dimensions: informative, participative, and accountable. Based on a unique data set consisting of six Italian social enterprises operating in the social service sector, we use a mixed-method approach
in order to study both managerial policy and stakeholders' perceptions towards transparency. From qualitative, exploratory, and multi-case analysis, it emerges that the nature of the relationship between the organization and its stakeholders shapes transparency dimensions through organizational structure. There are common patterns in this context that distinguish large enterprises with vertical
decision-making from smaller rms with horizontal processes: in the rst group,transparency is developed along its informative dimension and it is structured on a unilateral
ow of information that is aimed at controlling internal stakeholders. Whereas in the second group, transparency is mainly participative, designed as a two-way exchange of information with an explicit objective to allow mean-
ing co-creation. Using structural equation modelling, we nd that stakeholders' perceptions about transparency are relatively high and positively linked to organizational commitment, where trust plays a signicant mediating role. Tenure in the organization, formal membership, and job security display varying and, in some cases, opposing behaviors. The main contribution of this thesis to the literature in this area is that it highlights the need for understanding the interplay between the transmitter and the receiver of transparency. It further considers the impact of stakeholder relations to enable alternatives for developing dierent typologies of transparency