Die digitale Gesellschaft – Netzpolitik, Bürgerrechte und die Machtfrage: 17. Februar 2013

Als politischer Netzaktivist gehört Markus Beckedahl zu den führenden Vertretern einer Bewegung, die die Einflüsse neuer Medien auf die Gesellschaft kritisch begleitet und kommentiert. Ein Hauptaugenmerk gilt dabei dem Einfluss der Politik auf das Internet und seine politischen Gestaltungsmöglichkeiten. Er ist als Berater vielfach gefragt und Vorsitzender der „Digitalen Gesellschaft“

A novel multi-scale numerical model for prediction of texture-related impacts on fuel consumption

It is estimated that to overcome rolling resistance (RR) a typical vehicle, on average, consumes 4152 MJ/119 L of fuel annually, depending not only on vehicle-related factors but also on pavement-related factors. A slight improvement in surface properties may thus decrease fuel consumption, bringing substantial long-term socioeconomic benefits per capita per country. This aligns with ever-tighter limits on CO2 in the European Union (95 g/km until 2021), fostering sustainable construction and exploitation of tires and pavements. This paper outlines a newly developed multiscale three-dimensional numerical methodology to quantify texture-dependent RR due to indentation of aggregates into viscoelastic tread compound. It consists of a microscale tread block single-aggregate model and a macroscale car tire finite element model, rolling in a steady-state mode over a rigid smooth surface. Microscale interaction rates are deduced from the macroscale model. Tread compound is simulated by application of a time-dependent, linear, viscoelastic model. The microscale simulations enabled quantification of RR induced by an arrangement of surface aggregates. The outlined texture-dependent RR estimates are based on contact force moment around the contact patch center. The computed contact force results show a significant peak of normal force due to viscoelastic and inertia effects at the onset of the tire–surface contact phase, followed by a gradually decreasing/relaxing stress region with a sudden release at the end of the interaction. The contact forces seem to be of a reasonable distribution and magnitude. The proposed approach allows prediction of RR losses due to compressive forces at the microscale. Macro-distortional RR (which is not the subject of this paper) would then have to be added to find the total tire-related RR

Stakes are High: Essays on Brazil and the Future of the Global Internet

This workbook seeks to provide some background to the Global Meeting on the Future of Internet Governance (NETmundial) scheduled for April 23rd and 24th 2014 in São Paulo, Brazil. It is designed to help outline the internet policy issues that are at stake and will be discussed at NETmundial, as well as background on internet policy in Brazil. The workbook includes essays on the history of the NETmundial meeting and the Marco Civil process in Brazil; some background on the environment in Germany—with particular attention to the link between the meeting and the Snowden case; questions of legitimacy surrounding open processes for lawmaking; and comments on the material presented to the organizing committee by official and unofficial commenters. This workbook was produced as a part of the Internet Policy Observatory, a program at the Center for Global Communication Studies, the Annenberg School for Communication at the University of Pennsylvania. It was edited and curated by a steering committee including Ellery Roberts Biddle of Global Voices, Ronaldo Lemos of the Rio Institute for Technology and Society, and Monroe Price of the Annenberg School for Communication. They were assisted by Alexandra Esenler, Laura Schwartz-Henderson, and Briar Smith

A Review Of Road‒Related Soil Erosion: An Assessment Of Causes, Evaluation Techniques And Available Control Measures

Road construction has increased significantly worldwide in the last decades to meet the demands of the increasing human population and this has led to serious soil erosion problems, the bulk of which is unaccounted for, especially in the developing world. For comprehensive land management decisions and monitoring strategies, a review of work that has been done to assess soil erosion due to roads is critical. This article, therefore, reviews the causes of road‒related soil erosion, assessment methods and available control measures. Specifically, work provides an overview of (i) the linkages between roads and soil erosion; (ii) measurement and prediction of road‒related erosion; and (iii) erosion control and rehabilitation techniques. Literature shows that road construction results in hill-slope profile modification; removal of vegetation cover; as well as the formation of steep slopes that are prone to severe erosion. Furthermore, there is a variety of erosion control measures for controlling road‒related erosion although no study has demonstrated the method that is cost efficient and operational across different landscapes. We are of the view that this study provides guidance in future research on road‒related soil erosion across the developing world were sophisticated monitoring techniques are limited due to resource scarcity for assessing large areas. ResumenLa construcción de carreteras se ha incrementado ampliamente en todo el mundo durante las últimas décadas para cumplir con las demandas de la creciente población humana, lo que ha llevado a serios problemas de erosión de suelos, muchos de los cuales no se previeron, especialmente, en los países en desarrollo. Sobre las decisiones y supervisión de estrategias de un manejo completo del terreno se realizó una revisión al crítico trabajo que se ha hecho para medir la erosión en suelos causados por las carreteras. Por esta razón, este artículo revisa las causas de la erosion relacionada con la construcción de rutas y evalúa los métodos y medidas de control disponibles. Específicamente, este trabajo ofrece una revisión de (a) las relaciones entre las carreteras y la erosión de los suelos; (b) la medida y la predicción de la erosión vinculada a las carreteras, y (c) las técnicas de control de erosión y rehabilitación. La literature muestra que la construcción de carreteras produce modificaciones en el perfil inclinación, remueve la vegetación superficial y aumenta la inclinación en pendientes propensas a erosión severa. Además, existen varias medidas para controlar la erosión causada por la construcción de carreteras, a pesar de que ningún estudio ha demostrado el método que sea más eficiente y operacional para diferentes paisajes. Este estudio guía futuras investigaciones en la erosion causada por la construcción de caminos en los países en desarrollo donde las técnicas de supervisión sofísticas para la evaluación de grandes áreas son limitadas debido a la escasez de recursos

Numerical and experimental predictions of texture-related influences on rolling resistance

To overcome rolling resistance (RR) a typical vehicle on average consumes 4152 MJ/119 L of fuel annually as a result of bothvehicle and pavement factors. A slight improvement in surface texture arrangement may therefore decrease fuel consumptionbringing substantial long-term socio-economic benefits. This aligns with ever-tighter limits on CO2 in the USA (163 g/km until 2025) fostering sustainable construction/exploitation of tires/pavements. This paper describes a multi-scale 3-D numerical methodology to calculate micro-distortional RR and contact indentations of surface aggregates into visco-elastic tread compound accounting for loading, velocity, temperature, and compound properties. It consists of a micro-scale tread block single aggregate model and a macro-scale car tire finite element model, rolling in steady-state mode over a rigid smooth surface. The surface texture is idealized in terms of hemispherical indenters. The micro-distortional RR estimates are based on contact force and energy lost per single stone. The computed contact/normal forces peak significantly due to visco-elastic effects at the beginning of the tire–surface contact phase, followed by a gradually relaxing stress region with a sudden release at the end of the interaction. The contact forces appear to be of a reasonable distribution and magnitude. It is found that microdistortional RR is higher on a rougher and sparsely packed surface compared with a smoother and more tightly packed case. To determine the total tire-related RR, macro-distortional RR can then be added. The predictions were qualitatively confirmed and adjusted against real bituminous mixes by experimental testing, showing a reasonable agreement

Innovative Uses for Conventional Radiation Detectors via Pulse Shape Analysis

In this report we have discussed two applications for digital pulse shape analysis in Ge detectors: Compton suppression and {gamma}-ray imaging. The Compton suppression aspect has been thoroughly studied during the past few years, and a real-time, laboratory-prototype system has been fielded. A summary of results from that set up have been discussed here. The {gamma}-ray imaging aspect, while not yet developed experimentally, looks very promising theoretically as the simulations presented here have shown. Experimental work currently underway at Berkeley (as discussed in section 4.3) should help further guide us towards the proper developmental path

Spatial resolution attainable in germanium detectors by pulse shape analysis

There are several applications for which it is desirable to calculate the locations and energies of individual gamma-ray interactions within a high purity germanium (HPGe) detector. These include gamma-ray imaging and Compton suppression. With a segmented detector this can be accomplished by analyzing the pulse shapes of the signals from the various segments. We examine the fundamental limits to the spatial resolution attainable with this approach. The primary source of error is the series noise of the field effect transistors (FETs) at the inputs of the charge amplifiers. We show how to calculate the noise spectral density at the output of the charge amplifiers due to an optimally selected FET. This calculation is based only on the detector capacitance and a noise constant for the FET technology. We show how to use this spectral density to calculate the uncertainties in parameters, such as interaction locations and energies, that are derived from pulse shape analysis using maximum likelihood estimation (MLE) applied to filtered and digitized recordings of the charge signals. Example calculations are given to illustrate our approach. Experimental results are given that demonstrate that one can construct complete systems, from detector through data analysis, that come near the theoretical limits

Accidental wetlands - a southern African case study from the Kgaswane Mountain Reserve, Rustenburg

Wetlands form part of a diverse range of habitats and play an important role in the ecology and hydrological cycle but are amongst the most threatened ecological systems. It is therefore critical to understand the hydrology of wetlands, and their contributing water sources in particular, to ensure appropriate management of these systems. Land use activities not only alter the runoff characteristics of catchments, but also often result in modified flow regimes in watercourses. Wetlands often develop accidentally in anthropogenic landscapes and are not uncommon. However, these wetlands are poorly documented and researched. An accidental wetland formed in the Kgaswane Mountain Reserve, Rustenburg, due to leaking water infrastructure. The aim of this project was to categorise the wetland and confirm its origin, focussing on the role of the leakage. Methods included hydrogeomorphic classification, water ion composition analysis, as well as infield temperature and electrical conductivity measurements. Historical satellite imagery was used to study the evolution of the wetland over time. The electrical conductivity and ionic composition results suggest an unnatural water source, providing support that a leaking pipe caused the wetland to form. Management of accidental wetlands is discussed and the potential for future, related research is contemplated.https://www.tandfonline.com/loi/rsag20hj2022Geography, Geoinformatics and Meteorolog

Gamma-Ray Imaging With Coaxial HPGe Detector

We report on the first experimental demonstration of Compton imaging of gamma rays with a single coaxial high-purity germanium (HPGe) detector. This imaging capability is realized by two-dimensional segmentation of the outside contact in combination with digital pulse-shape analysis, which enables to image gamma rays in 4{pi} without employing a collimator. We are able to demonstrate the ability to image the 662keV gamma ray from a {sup 137}Cs source with preliminary event selection with an angular accuracy of 5 degree with an relative efficiency of 0.2%. In addition to the 4{pi} imaging capability, such a system is characterized by its excellent energy resolution and can be implemented in any size possible for Ge detectors to achieve high efficiency