368 research outputs found
Temporalities of migration. Time, data infrastructures and intervention
The dissertation explores the intersections between the temporalities of migration management and border-crossers’ temporalities. Scholarship has widely discussed both the temporalities shaping migration infrastructures and the temporalities of the migration journey. On the one hand, the quest for acceleration (smart borders, time politics of asylum) and pre-emptive governance (databases, mapping-monitoring devices) emerged as the main temporal goals and temporal strategies through which regulating - and hampering - migrants’ mobility. On the other hand, migrants’ temporal experiences have been analyzed in terms of waiting, acceleration and deceleration, cyclicity and repetition. Less attention has been paid to enquire the mutual, constitutive interrelationships and frictions between these two sets of temporalities. To articulate these issues, the dissertation is divided in three main parts. First, I analyze the relation between acceleration and (non)knowledge production by focusing on the “accelerated procedures” for asylum. These procedures are applied to people whose asylum applications are deemed as suspicious and likely to be rejected. I argue that the shortened timeframes shaping these procedures are a tool for hindering asylum seekers’ possibilities to collect and produce evidence supporting their cases, eventually facilitating and speeding up their removal for Member States’ territory. Second, I analyze the encounters between migration management and border-crossers during the identification practices carried out the Hotspots and during the asylum process in terms of “temporal collisions”. I develop the notion of “hijacked knowledge” to illustrate how these “temporal collisions” negatively affect border-crossers’ possibilities of action, by producing a significant lack of knowledge and awareness about the procedures to which they are subjected and their temporal implications. With the concept of “reactive calibration”, on the other hand, I suggest that once migrants become aware of the temporalities of control, they try to appropriate them by aligning their bodies, narrations and identities to those temporalities. The third part of the dissertation describes the situated intervention developed as part of my ethnographic activity. Drawing on participatory design, design justice and STS making and doing, I designed a role-playing game - My documents, check them out - seeking to involve border-crossers in the re-design of the categories usually deployed in migration management. The game was perceived by border-crossers as a learning activity and as a reflexive tool. However, the game proved to be a productive ethnographic device even when played by other actors (scholars, students, activists), as it allowed to reveal their knowledge and familiarity with the dynamics of migration management that are simulated by the game
The Ambivalence of Platforms: Between Surveillance and Resistance in the Management of Vulnerable Populations
This contribution aims to summarize and highlight the main themes emerged during the panel “Surveillance infrastructures or open platforms? Aid and control of vulnerable populations through digital data” that took place at the 8th STS Italia Conference. The panel invited to re-flect upon the ambivalence and ambiguity of digital platforms and data infra-structures for population management as well as on the highly diversified functions and users they support and attract. More precisely, presenters were encouraged to enquire how platforms and data infrastructures affect vulnerable populations and reconfigure the boundaries between the private and public domains: how do they allow empowering and innovative communication and resistance strategies? How, on the contrary, do they produce novel or exacerbate already existing vulnerabilities? How is the modern distinction between government, business, and civil society de facto reshuffled as a consequence? Although panel’s presentations discussed remarkably different types of platforms – from online maps and social net-works to public health databases and migration technologies – they overall emphasized that only a careful, situated analysis of the multiple socio-technical factors shaping users’ engagement might help to understand how – and why – those technologies become tools for control and surveillance or empowerment resources
Methodologies for the design of Positive Energy Districts: A scoping literature review and a proposal for a new approach (PlanPED)
Cities can substantially contribute to European Green Deal targets by accelerating their transition towards smarter, more efficient, and renewable-based energy models. In that context, European cities need to increase their self-sufficiency and the resilience of their energy system especially through the promotion of district and neighbourhood scale energy projects such as positive energy districts (PEDs). Despite the increasing interest for PEDs experienced in the last years, their deployment is currently hindered by the absence of an energy planning culture and the lack of adequately skilled personnel in cities. Indeed, there is a strong need for practical tools and guidelines that support practitioners in the design and implementation of PEDs. In that context, the present paper introduces PlanPED, a framework for the conception of methodologies for PED planning, design, and implementation, to support municipalities in their energy transition. PlanPED aims at providing a multiple perspective approach based on the most important elements from existing methodologies. In that sense, the paper begins with an overview of the state of the art, leading to the identification of trends, gaps, and good practices of current research. Then, based on this analysis, the novel framework PlanPED is introduced. It consists of three interconnected workflows that, if followed, enables to know which steps and resources need to be put in practice to initiate the transition towards PED, while recognizing the variability of contexts and necessities. By doing so, PlanPED seeks to facilitate the elaboration of tailored and practical roadmaps for the deployment of PEDs in cities
Integral energy performance characterization of semi-transparent photovoltaic elements for building integration under real operation conditions
In this paper, a methodology for the integral energy performance characterization (thermal, daylighting and electrical behavior) of semi-transparent photovoltaic modules (STPV) under real operation conditions is presented. An outdoor testing facility to analyze simultaneously thermal, luminous and electrical performance of the devices has been designed, constructed and validated. The system, composed of three independent measurement subsystems, has been operated in Madrid with four prototypes of a-Si STPV modules, each one corresponding to a specific degree of transparency. The extensive experimental campaign, continued for a whole year rotating the modules under test, has validated the reliability of the testing facility under varying environmental conditions.
The thermal analyses show that both the solar protection and insulating properties of the laminated prototypes are lower than those achieved by a reference glazing whose characteristics are in accordance with the Spanish Technical Building Code. Daylighting analysis shows that STPV elements have an important lighting energy saving potential that could be exploited through their integration with strategies focused to reduce illuminance values in sunny conditions. Finally, the electrical tests show that the degree of transparency is not the most determining factor that affects the conversion efficiency
Design, development and construction of an outdoor testing facility for semi-transparent photovoltaic modules
Building-integrated Photovoltaics (BIPV) is one of the most promising technologies enabling buildings to generate on-site part of their electricity needs while performing architectural functionalities. A clear example of BIPV products consists of semi-transparent photovoltaic modules (STPV), designed to replace the conventional glazing solutions in building façades. Accordingly, the active building envelope is required to perform multiple requirements such as provide solar shading to avoid overheating, supply solar gains and thermal insulation to reduce heat loads and improve daylight utilization. To date, various studies into STPV systems have focused on their energy performance based on existing simulation programs, or on the modelling, normally validated by limited experimental data, of the STPV modules thermal behaviour. Taking into account that very limited experimental research has been conducted on the energy performance of STPV elements and that the characterization in real operation conditions is necessary to promote an energetically efficient integration of this technology in the building envelope, an outdoor testing facility has been designed, developed and built at the Solar Energy Institute of the Technical University of Madrid. In this work, the methodology used in the definition of the testing facility, its capability and limitations are presented and discussed
Experimental characterization and implementation of an integrated autoregressive model to predict the thermal performance of vegetal façades
Experimental characterization and implementation of an integrated autoregressive model to predict the thermal performance of vegetal façade
Integral energy behaviour of photovoltaic semi-transparent glazing elements for building integration
La hipĂłtesis general que esta tesis quiere demostrar es que la integraciĂłn arquitectĂłnica de sistemas fotovoltaicos semitransparentes (STPV) puede contribuir a mejorar la eficiencia energĂ©tica de los edificios. Por lo tanto, la investigaciĂłn se centra en el desarrollo de una metodologĂa capaz de cuantificar la reducciĂłn de la demanda energĂ©tica del edificio proporcionada por estas novedosas soluciones constructivas. Al mismo tiempo, los parámetros de diseño de las soluciones STPV se han analizado para establecer cuales presentan el mayor impacto sobre el balance energĂ©tico global del edificio y por lo tanto tienen que ser cuidadosamente definidos a la hora de optimizar el comportamiento energĂ©tico del mismo. A la luz de estos objetivos, la metodologĂa de estudio se ha centrado en tres puntos principales: Caracterizar el comportamiento energĂ©tico global de sistemas STPV en condiciones de operaciĂłn realistas, similares a las que se darĂan en un sistema real; Caracterizar el comportamiento energĂ©tico global de sistemas STPV en condiciones controladas, con el objetivo de estudiar la variaciĂłn del comportamiento del los elementos en funciĂłn de parámetro de diseño y operaciĂłn; Evaluar el potencial de ahorro energĂ©tico global de los sistemas STPV en comparaciĂłn con soluciones acristaladas convencionales al variar de las condiciones de contorno constituidas por los parámetros de diseño (como el grado de transparencia), las caracterĂsticas arquitectĂłnicas (como el ratio entre superficie acristalada y superficie opaca en la fachada del edificio) y las condiciones climáticas (cubriendo en particular la climatologĂa europea). En sĂntesis, este trabajo intenta contribuir a comprender la interacciĂłn que existe entre los sistemas STPV y el edificio, proporcionando tanto a los fabricantes de los componentes como a los profesionales de la construcciĂłn informaciĂłn valiosa sobre el potencial de ahorro energĂ©tico asociado a estos nuevos sistemas constructivos. Asimismo el estudio define los parámetros de diseño adecuados para lograr soluciones eficientes tanto en proyectos nuevos como de rehabilitaciĂłn. ABSTRACT The general hypothesis this work seeks to demonstrate is that the architectural integration of Semi-Transparent Photovoltaic (STPV) systems can contribute to improving the energy efficiency of buildings. Accordingly, the research has focused on developing a methodology able to quantify the building energy demand reduction provided by these novel constructive solutions. At the same time, the design parameters of the STPV solution have been analysed to establish which of them have the greatest impact on the global energy balance of the building, and therefore which have to be carefully defined in order to optimize the building operation. In the light of these goals, the study methodology has focused on three main points: To characterise the global energy behaviour of STPV systems in realistic operating conditions, similar to those in which a real system will operate; To characterise the global energy behaviour of STPV systems in controlled conditions in order to study how the performance varies depending on the design and operating parameters; To assess the global energy saving potential of STPV systems in comparison with conventional glazing solutions by varying the boundary conditions, including design parameters (such as the degree of transparency), architectural characteristics (such as the Window to Wall Ratio) and climatic conditions (covering the European climatic conditions). In summary, this work has sought to contribute to the understanding of the interaction between STPV systems and the building, providing both components manufacturers and construction technicians, valuable information on the energy savings potential of these new construction systems and defining the appropriate design parameters to achieve efficient solutions in both new and retrofitting projects
Development and characterization of a standardized docking system for small spacecraft
Since the first mating manoeuvre in space, performed in 1966, many different docking mechanisms were developed, mainly for large manned spacecraft. The few systems recently conceived for small satellites have never been verified in space nor scaled to CubeSat size. In the near future, small spacecraft docking procedures could acquire great importance due to the need to share resources between clusters of low-weight and low-cost vehicles: in fact, small spacecraft market is rapidly growing, focusing on commercial low risk application, low budget scientific and educational missions. In this context, this document presents a novel docking mechanism to provide small spacecraft with the ability to join and separate in space, to realize multi-body platforms able to rearrange, be repaired or updated, thus overcoming the actual on board limitations of single small-scale satellites. As for now, the few proposed docking ports present (1) simple probe-drogue interfaces, unable to dock with same-gender ports, or (2) androgynous geometries, that can overcome that problem, but usually employing complex and non-axis-symmetric latches to perform the docking manoeuvre, that would demand robust and stringent navigation and control systems. The proposed solution overcomes the aforementioned drawbacks, using a semi-androgynous shape-shifting mechanism that actuating one interface changes the port into a “drogue" configuration, letting the other port penetrate it and closing around to create a solid joint. The mechanism design through the requirement definition and a trade-off between different concepts is presented, followed by the analysis of the dynamic behaviour of the selected solution, with particular attention to two aspects, i.e. the loads transmitted between the mating ports and the alignment tolerances requested to perform successful docking manoeuvres. Such analysis led to the definition of an instrumented prototype to verify the solution through simple validation tests, which demonstrated the mechanism operations and defined the alignment ranges, that lie in the range of +- 15 mm and up to 6 degrees. Last, a comparison with SPHERES UDP is presented, as part of the activities performed during a visit period at MIT Space Systems Laboratory
Comparative analysis of the thermal insulation performance of a façade enclosure integrated by vegetation under simultaneous windy and rainy climatic conditions
The literature offers some studies on the capacity of the greenery apparatus to decrease wind speed and regulate temperatures with the combination of the moisture retained by the plants and the air passing through them, but there is little on the maintenance of performance under particular weather conditions. The aim of this contri- bution is to verify the effectiveness of a vegetal façade in particularly windy conditions combined with rainy and/or high-irradiation events. The subject of the study is the enclosure of the Technology Innovation Centre for Development (itdUPM), on the Polytechnic University of Madrid, where a green wall prototype has been installed. For the purposes of the analysis, the environmental variables are examined and the monitoring data received from sensors positioned at the walls and skin of the insulated envelope are compared with the green face and without, comparing the differences in surface temperatures. These analyses are further examined by considering the correlation with different weather conditions. Experimentation shows a maintenance of per- formance, retaining an insulating capacity in all seasons, in both wind and rain, with results more evident in daylight hours. This contribute want to analyse the subtle variance between the performance of south and west facades. The strongest effect came forward during the summer season because the wall is affected by continuous irradiation on the south that is, also increased by hot weather
Temporalities of migration: time, data infrastructures and intervention
The dissertation explores the intersections between the temporalities of migration management and border-crossers’ temporalities. First, I analyze the relation between acceleration and (non)knowledge production by focusing on the “accelerated procedures” for asylum. These procedures are applied to people whose asylum applications are deemed as suspicious and likely to be rejected. I argue that the shortened timeframes shaping these procedures are a tool for hindering asylum seekers’ possibilities to collect and produce evidence supporting their cases, eventually facilitating and speeding up their removal for Member States’ territory. Second, I analyze the encounters between migration management and border-crossers during the identification practices carried out the Hotspots and during the asylum process in terms of “temporal collisions”. I develop the notion of “hijacked knowledge” to illustrate how these “temporal collisions” negatively affect border-crossers’ possibilities of action, by producing a significant lack of knowledge and awareness about the procedures to which they are subjected and their temporal implications. With the concept of “reactive calibration”, on the other hand, I suggest that once migrants become aware of the temporalities of control, they try to appropriate them by aligning their bodies, narrations and identities to those temporalities. The third part of the dissertation describes the situated intervention developed as part of my ethnographic activity. Drawing on participatory design, design justice and STS making and doing, I designed a role-playing game - My documents, check them out - seeking to involve border-crossers in the re-design of the categories usually deployed in migration management
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