Intergenerational justice starts now: Recognizing future generations in nuclear waste management

Intergenerational justice is an inherent component of nuclear waste management. By looking at challenges of intergenerational justice at various stages of the repository siting process, the following thesis is discussed: Current generations can anticipate notions of intergenerational justice by applying high procedural standards to enable equitable distribution between generations and thus adequately recognize the needs of future generations. Applying high standards in this context means a constantly critical, reflexive, and open process, without bias or selfishness. This requires representative bodies such as the German Council of the Young Generation ('Rat der jungen Generation') that act as a bridge to future generations.Intergenerationale Gerechtigkeit ist ein wesentlicher Bestandteil der nuklearen Abfallentsorgung. Anhand von Herausforderungen der intergenerationalen Gerechtigkeit während verschiedener Phasen des Standortauswahlverfahrens und der Endlagerung wird die folgende These diskutiert: Heutige Generationen können Vorstellungen von intergenerationaler Gerechtigkeit durch die Anwendung hoher Verfahrensstandards antizipieren, um eine gerechte Verteilung zwischen den Generationen zu ermöglichen und damit Bedürfnisse künftiger Generationen angemessen zu berücksichtigen. Die Anwendung hoher Standards bedeutet dabei einen konstant kritischen, reflexiven und offenen Prozess, ohne Voreingenommenheit und Eigennutz. Dies erfordert, dass repräsentative Gremien wie der 'Rat der jungen Generation' als Brücke zu künftigen Generationen fungieren

Is It All about a Science-Informed Decision? A Quantitative Approach to Three Dimensions of Justice and Their Relation in the Nuclear Waste Repository Siting Process in Germany

Nuclear waste management is a contested challenge that lasts for decades. Especially in Germany, the history of the usage of nuclear energy is conflictive and notions of justice are therefore omnipresent in the ongoing site selection process for a nuclear waste repository. Against the background of injustices caused by the deployment of nuclear energy, such as the obligation for current generations to deal with nuclear waste, questions of how to justly deal with nuclear waste and to find a just repository site arise. By conducting a survey among people that participate in the site selection process as well as people living in or representing an area that is still considered suitable, the assessment of different aspects of justice was evaluated. The role of a science-informed site decision without any political bias is considered highly important for a just site selection. Distributional aspects, such as notions of utilitarianism, retribution, or the exemption of environmentally burdened regions are generally not approved but more detailed questions have shown that such notions cannot be dismissed at this early stage of the site selection process. The difference for general agreement can also be observed for intergenerational recognition, as the recognition of future generations is regarded as necessary, but concrete implications (retrievability or enclosure) are assessed ambiguously. Although some factors of justice are assessed more importantly than others, the analysis has shown that the interrelations between the different dimensions of justice are manifold and the argument that one dimension can be substituted for another one is too reductive

Energy efficiency of mmWave massive MIMO precoding with low-resolution DACs

With the congestion of the sub-6 GHz spectrum, the interest in massive multiple-input multiple-output (MIMO) systems operating on millimeter wave spectrum grows. In order to reduce the power consumption of such massive MIMO systems, hybrid analog/digital transceivers and application of low-resolution digital-to-analog/analog-to-digital converters have been recently proposed. In this work, we investigate the energy efficiency of quantized hybrid transmitters equipped with a fully/partially-connected phase-shifting network composed of active/passive phase-shifters and compare it to that of quantized digital precoders. We introduce a quantized single-user MIMO system model based on an additive quantization noise approximation considering realistic power consumption and loss models to evaluate the spectral and energy efficiencies of the transmit precoding methods. Simulation results show that partially-connected hybrid precoders can be more energy-efficient compared to digital precoders, while fully-connected hybrid precoders exhibit poor energy efficiency in general. Also, the topology of phase-shifting components offers an energy-spectral efficiency trade-off: active phase-shifters provide higher data rates, while passive phase-shifters maintain better energy efficiency.Comment: Published in IEEE Journal of Selected Topics in Signal Processin

Improving urban bicycle infrastructure - an exploratory study based on the effects from the COVID-19 Lockdown

INTRODUCTION: During the COVID-19 lockdown significant improvements in urban air quality were detected due to the absence of motorized vehicles. It is crucial to perpetuate such improvements to maintain and improve public health simultaneously. Therefore, this exploratory study approached bicycle infrastructure in the case of Munich (Germany) to find out which specific bicycle lanes meet the demands of its users, how such infrastructure looks like, and which characteristics are potentially important. METHODS: To identify patterns of bicycle infrastructure in Munich exploratory data is collected over the timespan of three consecutive weeks in August by a bicycle rider at different times of the day. We measure position, time, velocity, pulse, level of sound, temperature and humidity. In the next step, we qualitatively identified different segments and applied a cluster analysis to quantitatively describe those segments regarding the measured factors. The data allows us to identify which bicycle lanes have a particular set of measurements, indicating a favorable construction for bike riders. RESULTS: In the exploratory dataset, five relevant segment clusters are identified: viscous, slow, inconsistent, accelerating, and best-performance. The segments that are identified as best-performance enable bicycle riders to travel efficiently and safely at amenable distances in urban areas. They are characterized by their width, little to no interaction with motorized traffic as well as pedestrians, and effective traffic light control. DISCUSSION: We propose two levels of discussion: (1) revolves around what kind of bicycles lanes from the case study can help to increase bicycle usage in urban areas, while simultaneously improving public health and mitigating climate change challenges and (2) discussing the possibilities, limitations and necessary improvements of this kind of exploratory methodology

Improving urban bicycle infrastructure-an exploratory study based on the effects from the COVID-19 Lockdown

Introduction: During the COVID-19 lockdown significant improvements in urban air quality were detected due to the absence of motorized vehicles. It is crucial to perpetuate such improvements to maintain and improve public health simultaneously. Therefore, this exploratory study approached bicycle infrastructure in the case of Munich (Germany) to find out which specific bicycle lanes meet the demands of its users, how such infrastructure looks like, and which characteristics are potentially important. Methods: To identify patterns of bicycle infrastructure in Munich exploratory data is collected over the timespan of three consecutive weeks in August by a bicycle rider at different times of the day. We measure position, time, velocity, pulse, level of sound, temperature and humidity. In the next step, we qualitatively identified different segments and applied a cluster analysis to quantitatively describe those segments regarding the measured factors. The data allows us to identify which bicycle lanes have a particular set of measurements, indicating a favorable construction for bike riders. Results: In the exploratory dataset, five relevant segment clusters are identified: viscous, slow, inconsistent, accelerating, and best-performance. The segments that are identified as best-performance enable bicycle riders to travel efficiently and safely at amenable distances in urban areas. They are characterized by their width, little to no interaction with motorized traffic as well as pedestrians, and effective traffic light control. Discussion: We propose two levels of discussion: (1) revolves around what kind of bicycles lanes from the case study can help to increase bicycle usage in urban areas, while simultaneously improving public health and mitigating climate change challenges and (2) discussing the possibilities, limitations and necessary improvements of this kind of exploratory methodology

Field-induced Conductance Switching by Charge-state Alternation in Organometallic Single-Molecule Junctions

Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These molecular intrinsic properties are usually addressed by varying the molecules electrochemical and magnetic environment, a procedure that requires complex setups with multiple terminals. Here we show that oxidation and reduction of organometallic compounds containing either Fe, Ru or Mo centres can solely be triggered by the electric field applied to a two-terminal molecular junction. Whereas all compounds exhibit bias-dependent hysteresis, the Mo-containing compound additionally shows an abrupt voltage-induced conductance switching, yielding high to low current ratios exceeding 1000 at voltage stimuli of less than 1.0 V. DFT calculations identify a localized, redox active molecular orbital that is weakly coupled to the electrodes and closely aligned with the Fermi energy of the leads because of the spin-polarised ground state unique to the Mo centre. This situation opens an additional slow and incoherent hopping channel for transport, triggering a transient charging effect of the entire molecule and a strong hysteresis with unprecedented high low-to-high current ratios.Comment: 9 pages, 4 figure