El Apagón en Buenos Aires 1999 Manejo de crisis en los sectores privados y públicos en la Argentina

In the City of Buenos Aires on the night to February 15, 1999, a cable fails in one of the Edesur substation tunnels, provoking a fire, which is followed by a power outage. Over 150.000 Edesur clients (approximately 600.000 individuals) in ten Buenos Aires quarters are affected in their homes, in offices, at banks, in the underground and in the street on the first day of the power outage. This would last for eleven days in Argentinean mid summer with temperatures over +30oC. What appeared to be a quickly solved technical problem soon developed into a social conflict and a political and economic crisis that would last for more than two months. This study analyses the social and political crisis that was produced in the wake of the power outage in Buenos Aires from a cognitive institutional perspective, in which decision making and communication are vital processes. Aspects such as problem framing, information processing, politicisation of crises and symbolic action are analysed within the Buenos Aires and Argentinean cultural, political and economic context. One central dimension of the analysis is the issue of privatisation of the public services; a particular feature of Argentinean political economy during the last decade. This is a case study on the Buenos Aires blackout but also a contribution to theoretical discussions on crisis management in the spheres of 'private' and 'public' of State and Market.privatisation of the public services; Corporate and Public Crisis; Management in Argentina

Exploring the role of granular activated carbon in drinking water production

Safe and clean drinking water is recognised as a human right by the United Nations, but water sources world-wide are affected by the widespread use of synthetic chemicals, creating a challenge that drinking water producers must address. Many of these synthetic chemicals, here referred to as organic micropollutants (OMPs), are not well removed by conventional drinking water treatment, and thus additional treatment steps are needed. Granular activated carbon (GAC) is a commonly used sorption material in water treatment processes. This thesis explores different roles of GAC filters in drinking water production: as a chemical barrier, as a biofilter, as a post-treatment step after ozonation and as a waste management step after nanofiltration. In two pilot-scale experimental set-ups, different kinds of raw and process water were treated in processes involving GAC filtration. Removal rates of a broad range of OMPs (including per- and polyfluoroalkyl substances; PFAS) were studied, along with microbial abundance and several parameters characterising natural organic matter (NOM) content. The results showed that GAC filters were more efficient with pre-ozonation, but the efficiency of OMP removal decreased over time. Inclusion of ozone treatment also introduced new challenges, as it was shown to increase bioavailability of NOM, which GAC filters were not fully able to remove. However, the GAC filters inevitably transitioned into biofilters over time, and these biofilters were able to remove more NOM when pre-ozonated. The in-depth information provided by this thesis on GAC filter performance over time under different conditions provides new insights into water treatment options to protect human health

Monitoring the low doping regime in graphene using Raman 2D peak-splits: Comparison of gated Raman and transport measurements

Avoiding charge density fluctuations and impurities in graphene is vital for high-quality graphene-based devices. Traditional characterization methods require device fabrication and electrical transport measurements, which are labor-intensive and time-consuming. Existing optical methods using Raman spectroscopy only work for doping levels higher than ~10^12 cm^-2. Here, we propose an optical method using Raman 2D peak-splitting (split between the Raman 2D1 and 2D2 peaks at low doping levels). Electrostatically gated Raman measurements combined with transport measurements were used to correlate the 2D peak-split with the charge density on graphene with high precision (2x10^10 cm^-2 per 2D peak-split wavenumber). We found that the Raman 2D peak-split has a strong correlation with the charge density at low doping levels, and that a lower charge density results in a larger 2D peak-split. Our work provides a simple and non-invasive optical method to quantify the doping level of graphene from 10^10 cm^-2 to 10^12 cm^-2, two orders of magnitude higher precision than previously reported optical methods. This method provides a platform for estimating the doping level and quality of graphene before fabricating graphene deviceshttps://arxiv.org/abs/1908.10961First author draf

High resolution image reconstruction with constrained, total-variation minimization

This work is concerned with applying iterative image reconstruction, based on constrained total-variation minimization, to low-intensity X-ray CT systems that have a high sampling rate. Such systems pose a challenge for iterative image reconstruction, because a very fine image grid is needed to realize the resolution inherent in such scanners. These image arrays lead to under-determined imaging models whose inversion is unstable and can result in undesirable artifacts and noise patterns. There are many possibilities to stabilize the imaging model, and this work proposes a method which may have an advantage in terms of algorithm efficiency. The proposed method introduces additional constraints in the optimization problem; these constraints set to zero high spatial frequency components which are beyond the sensing capability of the detector. The method is demonstrated with an actual CT data set and compared with another method based on projection up-sampling.Comment: This manuscript appears in the proceedings of the 2010 IEEE medical imaging conferenc

The Need for a Global Patent Market

If developed and developing countries’ national patent systems were integrated in the trade system, the result would be greater specialization among inventors and, with it, faster technological invention and productivity growth. Yet under current arrangements, World Trade Organization member states do not honor foreign inventors’ claims to their own inventions. More than ever, the world needs a new framework of trade rules to facilitate the exchange of human ideas across borders

Målstyrningen av den svenska skolan : blev det någon skillnad?

I mitten av 1990-talet ersattes den svenska skolans direktiv om hur undervisningen skulle gå till med en beskrivning av vilka resultat och mål som skulle uppnås. Syftet med denna uppsats var att öka förståelsen för hur några lärare upplevde hur skolarbetet hade påverkats av att den svenska barn- och ungdomsskolan övergått från att vara regelstyrd till att vara målstyrd. Sex lärare med lång erfarenhet intervjuades. De timslånga intervjuerna spelades in på band och transkriberades sedan. Resultaten från dessa intervjuer analyseras sedan hermeneutiskt utifrån Webers rationalitetsteori och Foucaults maktbegrepp regementalitet. Lärarna tyckte inte att målstyrningen hade lett till en effektivare skola där eleverna lär sig mer. Lärarna trodde inte heller att lärandet hade blivit mer lustfyllt, att skolarbetet blivit roligare för eleverna. De intervjuade lärarna uppgav att både de och eleverna kände sig mer stressade. De som hade förlorat mest på skolans övergång till målstyrning var de svaga eleverna, som av någon anledning hade svårt att nå målen för att bli godkända. Deras problem hade därigenom förtydligats på ett för dem negativt sätt

A simple KPFM-based approach for electrostatic-free topographic measurements: the case of MoS2_2 on SiO2_2

A simple implementation of Kelvin probe force microscopy is reported that enables recording topographic images in the absence of any component of the electrostatic force. Our approach is based on a close loop z-spectroscopy operated in data cube mode. Curves of the tip-sample distance as a function of time are recorded onto a 2D grid. A dedicated circuit holds the KPFM compensation bias and subsequently cut off the modulation voltage during well-defined time-windows within the spectroscopic acquisition. Topographic images are recalculated from the matrix of spectroscopic curves. This approach is applied to the case of transition metal dichalcogenides (TMD) monolayers grown by chemical vapour deposition on silicon oxide substrates. In addition, we check to what extent a proper stacking height estimation can also be performed by recording series of images for decreasing values of the bias modulation amplitude. The outputs of both approaches are shown to be fully consistent. The results exemplify how in the operating conditions of non-contact AFM under ultra-high vacuum, the stacking height values can dramatically be overestimated due to variations in the tip-surface capacitive gradient, even though the KPFM controller nullifies the potential difference. We show that the number of atomic layers of a TMD can be safely assessed, only if the KPFM measurement is performed with a modulated bias amplitude reduced at its strict minimum or, even better, without any modulated bias. Last, the spectroscopic data reveal that defects at the TMD/oxide interface can have a counterintuitive impact on the electrostatic landscape, resulting in an apparent decrease of the measured stacking height by conventional nc-AFM/KPFM compared to non-defective sample areas. Hence, electrostatic free z-imaging proves to be a promising tool to assess the existence of defects in atomically thin TMD layers grown on oxide