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With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb$^{-1}$ of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeV. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The efficiency in the cores of jets with transverse momenta between 200 GeV and 1600 GeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx, to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is $0.061 \pm 0.006 \textrm{(stat.)} \pm 0.014 \textrm{(syst.)}$ and $0.093 \pm 0.017 \textrm{(stat.)}\pm 0.021 \textrm{(syst.)}$ for jet transverse momenta of 200-400 GeV and 1400-1600 GeV, respectively. The European physical journal / C 77(10), 673 (2017). doi:10.1140/epjc/s10052-017-5225-7 Published by Springer, Berlin

This study employs an electricity system capacity panning model with detailed economic dispatch and unit commitment decisions/constraints to quantitatively answer two key questions: How does the enactment of the federal Inflation Reduction Act of 2022 impact the cost of electricity, greenhouse gas emissions, and investment in electricity capacity in the PJM Interconnection over the 2023-2035 period? Given new and expanded federal subsidies for clean electricity resources in the Inflation Reduction Act, what additional capacity investments and resource deployment would be required and at what cost for the PJM region to reduce greenhouse gas emissions 80-90% by 2035 while maintaining an affordable and reliable electricity supply? Executive summary: In August 2022, Congress passed and President Biden signed the Inflation Reduction Act (IRA), which enacts a comprehensive set of financial incentives (tax credits, grants, rebates, loans) that support all sources of carbon-free electricity, promote vehicle and building electrification and efficiency, and subsidize carbon capture and storage (CCS). The implementation of IRA means that the full financial weight of the federal government is now behind the clean energy transition. This will have transformative effects on the economics of decarbonization in the PJM Interconnection (and across the United States). IRA will spark a new, sustained period of growth in PJM electricity consumption, which could rise ~19% from 2021 to 2030. The law also subsidizes the cost of deploying new renewable energy capacity and maintaining the region’s existing nuclear fleet. As a result, this study finds that clean electricity could supply 60% [58-66% across sensitivities] of PJM demand in 2030, up from 48% [43-61%] without enactment of IRA. However, realizing this potential will require a dramatic acceleration in the pace of wind and solar interconnection and transmission expansion in the PJM Interconnection. The growth of lower-cost, carbon-free electricity under IRA will significantly reduce CO2 emissions from PJM power generation, which could fall 37% [3-66%] from 2019/2021 levels. In contrast, PJM emissions would increase 12% [0-15%] from 2021 levels without IRA. However, PJM emissions may rebound after 2032 when a production tax credit for existing nuclear reactors established by IRA is set to expire. Unless equivalent policy support is extended beyond 2032, our modeling finds 12 GW [0-33 GW] of the PJM nuclear fleet is likely to retire by 2035, with new natural gas capacity and generation increasing to fill the resulting gap and meet growing demand, reversing some of the emissions progress achieved through 2030. In addition to driving down greenhouse gas emissions, IRA also lowers the cost of electricity supply in the PJM region. We find the average cost of bulk electricity supply for PJM load serving entities (LSEs), including transmission expansion and state policy requirements, will be about $42/MWh [~$40-45/MWh] in 2030, about 5-10% lower than without IRA, and well below costs paid in 2019 ($50.2/MWh) and 2021 (~$61/MWh). The primary sources of cost savings are reduced wholesale energy prices, lower costs to meet state clean energy policy goals (due to federal subsidies), and growing demand (which spreads fixed costs over more MWh). While IRA puts the PJM region on a path to lower-cost electricity and lower greenhouse gas emissions, the new federal policy is not sufficient to drive deep decarbonization of the PJM interconnection on its own. Fortunately, by subsidizing the cost of all new carbon-free electricity resources, IRA also makes it cheaper and easier for PJM states to reduce emissions further while preserving affordability. Part 2 of this study presents a cost-optimized blueprint of the additional capacity investments and resource deployment required for the PJM region to deeply decarbonize over the 2023-2035 period. Specifically, we apply two stylized policy constraints and model the evolution of the PJM capacity mix and operations to meet those constraints: A clean electricity standard (CES) requiring increased shares of carbon-free electricity generation in the region (55% clean share by 2025, 70% by 2030, 85% by 2035), and; A CO2 emissions cap and trading scheme (cap & trade) requiring decreasing region-wide emissions (58% below 2005 emissions by 2025, 80% by 2030, 95% by 2035) This study finds that, due to passage of IRA, the PJM region could cut CO2 emissions from power generation by 80-90% by 2035 while keeping average bulk electricity supply costs for LSE’s comparable to or lower than levels experienced in recent years (2019 & 2021). However, deep decarbonization in the PJM region will require much more rapid expansion of low-carbon electricity resources and supportive transmission expansion above and beyond the rates of deployment made economical by IRA. By 2035, the region will also likely deploy more advanced ‘clean firm’ resources like gas power plants with carbon capture and storage (CCS) or long-duration electricity storage technologies (LDS), to replace coal- and gas-fired power capacity. We also identify and map several affordable resource portfolios and spatial patterns for clean electricity resource siting across the PJM region, demonstrating that the region has some flexibility to address local priorities and concerns.

La gestion des risques a réduit la vulnérabilité aux inondations et aux sécheresses dans le monde1,2, mais leurs impacts continuent d'augmenter3. Une meilleure compréhension des causes de l'évolution des impacts est donc nécessaire, mais a été entravée par un manque de données empiriques4,5. Sur la base d'un ensemble de données mondiales de 45 paires d'événements qui se sont produits dans la même zone, nous montrons que la gestion des risques réduit généralement les impacts des inondations et des sécheresses, mais fait face à des difficultés pour réduire les impacts d'événements sans précédent d'une ampleur jamais connue auparavant. Si le deuxième événement était beaucoup plus dangereux que le premier, son impact était presque toujours plus élevé. En effet, la gestion n'a pas été conçue pour faire face à de tels événements extrêmes : par exemple, ils ont dépassé les niveaux de conception des digues et des réservoirs. Dans deux cas de réussite, l'impact du deuxième événement, plus dangereux, a été plus faible, en raison de l'amélioration de la gouvernance de la gestion des risques et des investissements élevés dans la gestion intégrée. La difficulté observée à gérer des événements sans précédent est alarmante, étant donné que des événements hydrologiques plus extrêmes sont projetés en raison du changement climatique3. La gestión de riesgos ha reducido la vulnerabilidad a las inundaciones y sequías a nivel mundial1,2, pero sus impactos siguen aumentando3. Por lo tanto, se necesita una mejor comprensión de las causas de los impactos cambiantes, pero se ha visto obstaculizada por la falta de datos empíricos4,5. Sobre la base de un conjunto de datos global de 45 pares de eventos que ocurrieron dentro de la misma área, mostramos que la gestión de riesgos generalmente reduce los impactos de inundaciones y sequías, pero enfrenta dificultades para reducir los impactos de eventos sin precedentes de una magnitud no experimentada anteriormente. Si el segundo evento era mucho más peligroso que el primero, su impacto era casi siempre mayor. Esto se debe a que la gestión no fue diseñada para hacer frente a tales eventos extremos: por ejemplo, superaron los niveles de diseño de diques y embalses. En dos casos de éxito, el impacto del segundo evento, más peligroso, fue menor, como resultado de una mejor gobernanza de la gestión de riesgos y una alta inversión en la gestión integrada. La dificultad observada para gestionar eventos sin precedentes es alarmante, dado que se proyectan eventos hidrológicos más extremos debido al cambio climático3. Risk management has reduced vulnerability to floods and droughts globally1,2, yet their impacts are still increasing3. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data4,5. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change3. أدت إدارة المخاطر إلى تقليل التعرض للفيضانات والجفاف على مستوى العالم1,2، ومع ذلك لا تزال آثارها تتزايد3. لذلك هناك حاجة إلى فهم أفضل لأسباب تغير التأثيرات، ولكن أعيق ذلك بسبب نقص البيانات التجريبية4، 5. على أساس مجموعة بيانات عالمية مكونة من 45 زوجًا من الأحداث التي وقعت داخل نفس المنطقة، نظهر أن إدارة المخاطر تقلل عمومًا من آثار الفيضانات والجفاف ولكنها تواجه صعوبات في الحد من آثار الأحداث غير المسبوقة ذات الحجم الذي لم تشهده من قبل. إذا كان الحدث الثاني أكثر خطورة من الأول، فإن تأثيره كان دائمًا أعلى. وذلك لأن الإدارة لم تكن مصممة للتعامل مع مثل هذه الأحداث المتطرفة: على سبيل المثال، تجاوزت مستويات تصميم السدود والخزانات. في قصتي نجاح، كان تأثير الحدث الثاني، الأكثر خطورة، أقل، نتيجة لتحسين حوكمة إدارة المخاطر والاستثمار العالي في الإدارة المتكاملة. إن الصعوبة الملحوظة في إدارة الأحداث غير المسبوقة تنذر بالخطر، بالنظر إلى أنه من المتوقع حدوث المزيد من الأحداث الهيدرولوجية المتطرفة بسبب تغير المناخ3.

Current ecological and social crises are fuelling the idea that societies have arrived at an impasse. The “old narrative” which prioritises the pursuit of economic growth does not provide meaningful solutions to the various challenges societies are currently facing. On the contrary, it seems to be a fundamental source of several of its predicaments. Criticisms of this old narrative have existed for decades, alongside the emergence of alternative visions of a good life for all within environmental limits. This report will show that the scientific literature in this field is converging towards a sound theoretical foundation for a new narrative based on the distinction between three dimensions: Wellbeing reflects the average wellbeing of the current generation. Inclusion relates to the distribution of wellbeing between regions and social groups. Sustainability refers to the wellbeing of future generations. In accordance with these dimensions, the main socio-political goal of the new narrative envisioned is therefore defined as sustainable and inclusive wellbeing. However, relative to the economic growth narrative, new narratives have only had a small impact on public policies of national governments or international governance, laws, and treaties. Why? This is one of the enduring questions in the “Beyond-Growth” debate this theoretical framework seeks to address. For this purpose, the theoretical framework develops a theory of institutional change conceptualising how narratives influence the policies, governance, and technical infrastructure (i.e. the metrics, accounts, and macroeconomic models) that shape our societies. The framework is applied to examine both the enduring dominance of the economic growth narrative and the reasons behind the limited success of new narratives thus far. Moreover, the theory of institutional change outlines how a shift from economic growth towards a new narrative may be orchestrated, thus tilting the scale towards sustainable and inclusive wellbeing. It is argued that the establishment of technical infrastructure presents a crucial lever to shape governance and policies, which may give rise to a virtuous circle supporting the institutionalisation of the sustainable and inclusive wellbeing narrative. Given the importance of the technical infrastructure to advance a new narrative within the political institutions, this report provides an interdisciplinary theoretical synthesis to guide the selection and development of metrics, accounting frameworks, and macroeconomic models in line with the sustainable and inclusive wellbeing narrative. The report concludes with eight practical recommendations on how various actors can support the tilting of the scale towards the sustainable and inclusive wellbeing narrative.

Half-wavelength AC transmission (HWACT) is an ultra-long distance AC transmission technology, whose electrical distance is close to half-wavelength at the system power frequency. It is very important for the construction and operation of HWACT to analyze its fault features and corresponding protection technology. In this paper, the steady-state voltage and current characteristics of the bus bar and fault point and the steady-state overvoltage distribution along the line will be analyzed when a three-phase symmetrical short-circuit fault occurs on an HWACT line. On this basis, the three-phase fault characteristics for longer transmission lines are also studied. Keywords: Half-wavelength AC transmission, Fault characteristics, Three-phase short-circuit, Fault distance, Overvoltage