Релятивистское приближение для определения положений минимумов дифференциальных сечений и точек полной спиновой поляризации процесса упругого рассеяния электронов на тяжелых атомах

Пропонується метод оптичного потенціалу для описання процесу потенціального пружного розсіювання електронів багатоелектронними атомами з релятивістською поправкою до обмінної взаємодії. Ця поправка також використовується при самоузгоджених розрахунках атомних характеристик та величини дипольної статичної поляризовності атома-мішені. Підхід базується на наближенні локальної густини теорії функціонала густини та застосовується для розрахунку енергій та кутів особливостей у диференціальних перерізах і функціях спінової поляризації — відповідно критичних мінімумів та точок повної (100%) поляризації — при розсіюванні електронів на атомах ртуті в широкій, 10–1500 еВ, області енергій зіткнень.The optical potential approach has been suggested to describe the process of potential elastic electron scattering by a multielectron atom with the relativistic correction to the exchange interaction. This correction is also used for the self-consistent calculation of atomic characteristics and the target atom dipole static polarizability. The above approach is based on the local density approximation of the density functional theory. It is applied to calculate the energies and angles of the features in the differential cross sections and spin polarization functions, i.e. the critical minima and the points of total (100%) polarization of the electron scattering by Hg atoms in the wide (10–1500 eV) impact energy range

Public expectations about the impact of COVID-19 on climate action by citizens and government

Since the onset of the COVID-19 crisis many have opinionated on how it may affect society’s response to climate change. Two key questions here are how COVID-19 is expected to influence climate action by citizens and by the government. We answer these by applying topic modelling to textual responses from a survey of Spanish citizens. The identified topics tend to be more negative than positive, and more optimistic concerning future climate action by citizens. Positive views involve increasing pro-environmental behavior and are more common among younger, higher educated and male respondents as well as among those who perceive climate change as a serious threat or positively assessed COVID-19 confinement. Negative topics express concern that financial resources for climate action will be limited due to a focus on healthcare and economic recovery. In addition, they mention government mismanagement and waste due to use of protective measures like masks and gloves as impediments to effective climate action. Copyright: © 2022 Savin et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Unraveling the Nexus: Exploring the Pathways to Combined Resource Use

In response to the unprecedented decline in global natural resource endowments, the so-called nexus framework is gaining increasing influence on resource management practices. In this research, we approach the resource nexus through the concept of nexus pathways. Nexus pathways are configurations that resource flows follow along supply chains leading to the combined use of two or more resources. Three general types of pathways are identified: direct (on-site use), dependent (one-way supply chains), and interdependent (supply-chain feedbacks). We quantify and compare each pathway by means of multiregional input-output analysis and structural path analysis, and apply this approach to a comparative case study on the water-energy nexus (WEN) in the United States and China. Interdependencies or feedbacks are generally thought to be relevant for the WEN, especially between water and energy sectors. Our economy-wide analysis for both countries indicates, however, that feedbacks neither play an important role in the WEN nor substantially take place between water and energy sectors. The most important feedbacks contribute to less than 1% of total resource use, and these take place mostly between manufacturing sectors. Overall, the studied WEN is mostly driven by dependent pathways and, to a lesser degree, direct resource use. Comparative differences between the two countries are largely explained by differences in economic structure, technology, and resource endowments. Our findings call into question current research and policy focus and suggest greater attention to less complex, but more determining, pathways leading to absolute resource use

A systems perspective on water markets: barriers, bright spots, and building blocks for the next generation

Unidad de excelencia María de Maeztu CEX2019-000940-

Managing the cascading risks of droughts: institutional adaptation in transboundary rivers

Transboundary river basins experience complex coordination challenges during droughts. The multi‐scale nature of drought creates potential for spillovers when upstream adaptation decisions have cascading impacts on downstream regions. This paper extends the institutional analysis and development (IAD) framework to examine drought adaptation decision‐making in a multi‐jurisdictional context. We integrate concepts of risk management into the IAD framework to characterise drought across its natural and human dimensions. A global map identifies regions where severe droughts combine with institutional fragmentation to require coordinated adaptation. We apply the risk‐based IAD framework to examine drought adaptation in the Rio Bravo/Grande – an archetypical transboundary river shared by the US and Mexico and by multiple states within each country. The analysis draws on primary data and a questionnaire with fifty water managers in four distinct, yet inter‐linked, ‘institutional catchments’, which vary in terms of their drought characteristics, socio‐economic attributes and governance arrangements. The results highlight the heterogeneity of droughts and uneven distribution of their impacts due to the interplay of drought hazards and institutional complexity. Transboundary water sharing agreements influence the types and sequence of interactions between upstream and downstream jurisdictions, which we describe as spillovers that involve both conflict and cooperation. Interdependent jurisdictions often draw on informal decision‐making venues (e.g. data sharing, operational decisions) due to the higher transaction costs and uncertainty associated with courts and planning processes, yet existing coordination and conflict resolution venues have proven insufficient for severe, sustained droughts. Observatories will be needed to measure and manage the cascading risks of drought

Comprendre l'action collective dans la gestion de l'eau en agriculture en Europe

International audienceThe paper addresses the interactions between state intervention and collective action for water quality/quantity management by resource users in European rural areas. Using game theory, we model the incentive structure of different action situations underlying water management issues (social dilemmas, zero-sum games) to specify how the state may intervene to promote collective action. This analytical framework is then applied to five empirical cases across the EU covering diverse action situations. These cases differ in terms of collective action purpose (water management operation; decision-making on projects) and spatial scale (local; regional level) so as to capture diversity in settings. The analysis provides for first insights on the channels used by the state to promote local collective action for water management and a research agenda on the topic

Comprendre l'action collective pour la gestion de l'eau en Europe

International audienceThe paper addresses the interactions between state intervention and collective action for water quality/quantity management by resource users in European rural areas. Using game theory, we model the incentive structure of different action situations underlying water management issues (social dilemmas, zero-sum games) to specify how the state may intervene to promote collective action. This analytical framework is then applied to five empirical cases across the EU covering diverse action situations. These cases differ in terms of collective action purpose (water management operation; decision-making on projects) and spatial scale (local; regional level) so as to capture diversity in settings. The analysis provides for first insights on the channels used by the state to promote local collective action for water management and a research agenda on the topic

Action collective et intervention publique dans la gestion agricole de l'eau en Europe

International audienceThe paper addresses the interactions between state intervention and collective action for water quality/quantity management by resource users in European rural areas. Using game theory, we model the incentive structure of different action situations underlying water management issues (social dilemmas, zero-sum games) to specify how the state may intervene to promote collective action. This analytical framework is then applied to five empirical cases across the EU covering diverse action situations. These cases differ in terms of collective action purpose (water management operation; decision-making on projects) and spatial scale (local; regional level) so as to capture diversity in settings. The analysis provides for first insights on the channels used by the state to promote local collective action for water management and a research agenda on the topic