Reference Scenario Research Articles

Genomic selection strategies for the German Merino sheep breeding programme - A simulation study.

Genomic selection is widely implemented in livestock breeding programmes across species. Its potential is also evident for sheep breeding; however, it has several limitations, particularly because of the high genetic diversity across and within sheep breeds. In Germany, the predominant sheep breed is the Merino sheep. Until now, there has been no use of genomic selection in the German Merino sheep breeding programme. In this simulation study, different genomic selection strategies were compared with a reference scenario with a breeding value estimation based on pedigree BLUP. A simplified version of the German Merino sheep breeding programme, including a health and a production trait in the breeding goal, was simulated via the R package Modular Breeding Program Simulator (MoBPS). Real genotype data were used to create a population specific simulation. The reference scenario was compared with several alternative scenarios in which selection was based on single-step GBLUP (ssGBLUP) breeding value estimation with varying genotyping strategies. In addition to scenarios in which all male and all male plus all female lambs were genotyped, scenarios with a preselection of lambs, that is only a certain proportion (top 25%, top 50%) genotyped, were simulated. The results revealed that genetic gain increased with increasing numbers of available genotypes. However, marginal gains decreased with increasing numbers of genotypes. Compared with the reference scenario, genotyping the top 25% of male lambs increased the genetic gain for the breeding ram population by 13% for both traits whereas genotyping the top 50% of male lambs or all male lambs led to increases of 18% (17%) or 26% (21%) for the health (production) trait, respectively. The potential of genotyping females in addition to male lambs was less evident on the male side with no significant differences between the scenarios with different proportions of genotyped females. The results have shown that genomic selection can be a valuable tool to increase genetic gain in the German Merino sheep population and that the genotyping of a certain proportion of animals might lead to substantial improvement over pedigree-based breeding value estimation. Nevertheless, further studies, especially economic evaluations, are needed before practical implementation.

Study of The Energy, Economic, Environmental, and Thermal Comfort Impact of The Integration of Hemp Concrete and Hemp Plaster in a Residential Building Envelope in Morocco

In the building sector, the majority of efforts are aimed at achieving greater energy efficiency, a low carbon footprint, and optimum thermal comfort to make buildings more efficient, more sustainable, and more pleasant to live in. In this context, this paper aims to assess the impact of integrating environmentally friendly and green materials (lime-hemp plaster and hemp concrete) into the envelope of an existing residential building. A numerical simulation study was carried out using TRNSYS 18, in four Moroccan climates: Mediterranean, cold semi-arid, hot semi-arid, and hot and dry desert, to study the energy, economic, and environmental impact, as well as that of the thermal comfort. The proposed construction scenarios are compared with the reference scenario in terms of heating and cooling requirements, electricity bills, carbon footprint, and percentage of annual thermal discomfort. The results show that energy savings are highest in the cold semi-arid climate (Oujda) at around 24%. Hemp concrete construction is more effective in reducing heating requirements, with a reduction of up to 39.4%. For cooling, the reduction is only 15.5%. The economic and environmental study shows that using materials such as hemp concrete in an optimal construction and climatic context can reduce electricity bills by 25% and CO2 emissions by around 23.7%. However, the reduction in terms of hours of discomfort is not yet significant enough. Hence the need to combine this technique with other strategies based on bioclimatic design. The use of hemp plaster and concrete for renovating existing buildings or constructing new ones represents a very promising alternative from several points of view: energy, economic, and environmental.

Negative triangularity scenarios: from TCV and AUG experiments to DTT predictions

Abstract Experiments, gyrokinetic simulations and transport predictions were performed to investigate if a negative triangularity (NT) L-mode option for the Divertor Tokamak Test (DTT) full-power scenario would perform similarly to the positive triangularity (PT) H-mode reference scenario, avoiding the harmful edge localized modes (ELMs). The simulations show that a beneficial effect of NT coming from the edge/scrape-off layer (SOL) region ρ tor > 0.9 is needed to allow the actual NT L-mode option to perform like the PT H-mode. Dedicated experiments at TCV and AUG, with DTT-like shapes, show an optimistic picture. In TCV, experiments indicate that even with the relatively small triangularity of the DTT NT scenario, a large beneficial effect of NT comes from the plasma edge and SOL, allowing NT L-modes to outperform PT L-modes with the same power input, reaching the same central pressures as PT H-modes with twice as much applied heating power. For AUG, NT plasmas go into H-mode more easily than for TCV, but always present much smaller pedestals compared with PT plasmas with the same input power, showing a much weaker or absent ELM activity. However, NT has a smaller beneficial effect for AUG than for TCV, with NT pulses outperforming PT pulses with the same input power only for an ECRH-only case with relatively low input power. For the considered AUG cases, PT pulses perform better than NT ones at higher ECRH power or with mixed NBI and ECRH power. Based on this analysis, the NT option is a viable alternative for the DTT full power scenario, providing high performance plasmas with reduced or absent ELMs.

Techno-Economic and CO2 Emissions Analysis of the Molten Carbonate Fuel Cell Integration in a DRI Production Plant for the Decarbonization of the Steel Industry

Developing low-carbon systems for the steel industry is increasingly considered necessary for contributing to the targets of CO2 emission reduction requested by modern environmental policies. This work focuses on a process for decarbonizing primary steel production by integrating an MCFC system in a DRI production plant based on the Energiron ZR process configuration. An MCFC system can be used to remove CO2 from the flue gases while producing electricity and reducing the net electric consumption of the DRI plant. The reference scenario, the carbon capture case, and an additional hydrogen-based H-DRI system using high temperature electrolysis are simulated using Aspen Plus to evaluate and compare their energy and environmental performance. The results show that even considering the additional power consumption of the complete carbon capture and separation system, the overall electrical consumption of the carbon capture case is decreased by 78 % and the direct CO2 emissions by up to 95 %. Furthermore, reduced electricity consumption reduces scope 2 emissions, increasing the sustainability of the process in the steel industry. On the other hand, the H-DRI case decreases primary energy consumption by 24 % but significantly increase electricity requirement; thus, it represents a better future solution when cheap low-CO2 electricity is available. The plant configurations are compared economically by retrieving investment and operational costs from the open literature to estimate the levelized cost of DRI and the cost of CO2 avoided. The results show that installing the MCFC and the anode purification system increases the investment costs by 38 % compared to a conventional plant. However, the lower electricity consumption and carbon tax expenditure lead to a comparable final DRI product cost. Contrarily, due to the electrolyzer high investment and operational costs, the additional marginal DRI cost of the H-DRI case is 31 % higher. Finally, the sensitivity analysis on the main variable costs shows that, independently from the electricity and natural gas price, the carbon capture case is economically competitive to the reference scenario, considering a carbon tax of 60 €/tCO2 or higher. At the same time, the H-DRI solution requires low electricity prices to be competitive. In conclusion, even if, in the long term, the objective is to completely replace the use of fossil fuels with renewable energy, in the short term, the implementation of MCFC in the DRI plant can significantly reduce the environmental impact of primary steel production without significant economic penalization.

Pathways for the US food processing sector under economy-wide net zero in a multisector dynamic framework

The food processing sector is a large, energy-consuming and CO2-emitting industrial sector. The sector was estimated to account for 6 % of US industrial CO2 emissions in 2020. The sector uses significant amounts of fossil fuels, biomass, and electricity to perform a range of operations such as baking, drying, and refrigeration. Additionally, the sector is tightly linked to the agriculture and land use sectors. In this analysis, we use the Global Change Analysis Model (GCAM), a coupled, energy-economy-agriculture-land-use-water-climate systems model, to examine the role of the food processing sector in the EMF37 2050 US net-zero CO2 scenario. We explore the implications for technology and fuel choice and go beyond to examine US food consumption, food prices, and land-use change. To better understand the sensitivity of our results to alternative developments, we assess multiple sensitivity scenarios for the US and other world regions, with a focus on varied food processing energy intensity pathways.We find that along the EMF37 US net-zero path, the food processing sector electrifies the majority of its process heat. We also find that the industry phases-down natural gas use and completely phases-out coal. Additionally, we observe a marginal decrease in US food consumption per capita relative to our reference scenario. This primarily occurs due to the increase in consumer food prices resulting from increased demand for purpose-grown biomass crops, which compete with food crops for land resources. Finally, cumulative energy savings of 4.2 EJ are achieved from 2020 to 2050 in a scenario in which the US reduces its food processing intensity to EU-15 levels.

Budget impact analysis of introducing fruquintinib for metastatic colorectal cancer previously treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy and biologics in the United States from the payer perspective

Aims Fruquintinib is a selective small molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR)-1, -2, and -3 recently approved in the United States (US) for the treatment of adult patients with metastatic colorectal cancer (CRC) who have previously been treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild-type and medically appropriate, anti-epidermal growth factor receptor therapy. This study aimed to estimate the 5-year budget impact of fruquintinib from a US payer perspective (commercial and Medicare). Materials and methods A budget impact model was developed to compare two scenarios: a reference scenario in which patients received regorafenib, trifluridine/tipiracil, or trifluridine/tipiracil with bevacizumab and an alternative scenario in which patients received reference scenario treatments or fruquintinib. Market shares were evenly divided across available options. A 5-year time horizon and a hypothetical health plan of 1 million members was assumed. The model included epidemiological inputs to estimate the eligible population; clinical inputs for treatment duration, progression-free survival, overall survival, and adverse event (AE) frequency; and cost inputs for treatment, AEs, disease management, subsequent therapy, and terminal care costs. Budget impact was reported as total, per member per year (PMPY), and per member per month (PMPM). Results The model estimated an eligible population of 194 patients (39 per year) over 5 years. In the base case, the estimated 5-year budget impact of fruquintinib was $4,077,073 ($0.82 PMPY and 0.07 PMPM) for a commercial health plan. During the first year, the estimated budget impact was $627,570 ($0.63 PMPY and 0.05 PMPM). Results were robust across sensitivity analyses. PMPM costs from the Medicare perspective were greater than the base-case (commercial) ($0.17 vs. $0.07) due to higher incidence of CRC in that population. Conclusions Fruquintinib is associated with a low budget impact for payers based on proposed thresholds in the US.

Optimising the Energy and Resources of Hotel Buildings in Cameroon from a Zero-Carbon Perspective

This article explores the potential for Cameroonian hotel buildings to achieve optimal energy and resource use, contributing to a zero-carbon future. It examines the opportunities that lie in high-performing hotels to achieve the country's ambitious environmental objectives such as reducing its greenhouse gas emissions by 32% by 2035 compared with the reference scenario under the Paris Agreement. Then, the article delves into the existing landscape of green building labels and certifications while focusing on those related on hotels specifically like the Green Key. It acknowledges the various hotels categories present in the country and how their specific characteristics influence resource demands. Additionally, it presents the regulations governing the construction and conversion of hotel establishments. Furthermore, the article discusses strategies for optimising the performance of building resources within the tropical context. These involve improving the insulation of the building envelope, the efficiency of systems and the use of renewable energy sources. The article highlights the importance of the prescriptive approach for assessing and the energy performance approach for optimising building performance, using the accessible EDGE energy simulation software. Those approaches are defined in the Ivorian Inter-ministerial Order No. 134/MPEER/MCLU of 18 November 2020, given that Cameroon and Côte d'Ivoire have some similar climate zones. To achieve the EDGE Zero Carbon level, it is essential to demonstrate minimum savings of 40% of energy, 20% of water and 20% of grey energy in materials, and 100% of energy- related emissions neutralised either by renewable energies or by carbon offsets. Finally, the concept of green financing is introduced, examining its potential to facilitate

Modelling the impacts of climate change on agrochemical fate and transport by water on a catchment scale

The export of agrochemicals and their transformation products (TPs) following their application in the agricultural fields poses a threat to water quality. Future changes in climatic conditions (e.g. extreme weather events such as heavy rainfall or extended dry periods) could alter the degradation and mobility of agrochemicals. In this research, we use an integrated modelling framework to understand the impact of extreme climate events on the fate and transport of the agrochemical S-Metolachlor and two of its TPs (M-OXA, Metolachlor Oxanilic Acid and M-ESA, Metolachlor Ethyl Sulfonic Acid). This is done by coupling climate model outputs to the Zin-AgriTra agrochemical reactive transport model in four simulation scenarios. 1) Reference (2015–2018), 2) Very dry (2038–2041), 3) Very wet (2054–2057) and 4) High temperature (2096–2099) conditions of a selected RCP8.5 based regional climate scenario. The modelling framework is tested on an agricultural catchment, Wulka, in Burgenland, Austria. The model results indicate that 13–14 % of applied S-Metolachlor is retained in the soil, and around 85 % is degraded into TPs in the different scenarios. In very dry and high-temperature scenarios, degradation is higher, and hence, there is less S-Metolachlor in the soil. However, a large share of formed M-OXA and M-ESA are retained in the soil, which is transported via overland and groundwater flow, leading to a build-up effect in M-OXA and M-ESA river concentrations over the years. Though a small share of S-Metolachlor and TPs are transported to rivers, their river export is affected by the intensity and amount of rainfall. The very wet and high-temperature scenarios show higher S-Metolachlor and TP concentrations at the catchment outlet due to higher river discharge. The reference scenario shows higher river peak concentrations associated with higher overland flow caused by measured hourly rainfall compared to disaggregated daily precipitation data in the other scenarios.

Opportunities to integrate Ecosystem Services into Life Cycle Assessment (LCA): a case study of milk production in Brazil

World dairy production is growing rapidly having increased by 339 million tons over the last twenty years. However, it remains unclear how anthropic activities in the milk sector can impact the Ecosystem Services (ES) supply to society. The aim of this study was to propose and determine the Net Environmental Performance (NEP) of different milk production systems. For this purpose, a case study on a confined compost barn farm, located in southeastern Brazil was selected as reference scenario and compared with three other systems. The mapping of ES benefits was carried out using the Common International Classification of Ecosystem Services, while environmental impacts were calculated using Life Cycle Assessment (LCA). The LCA results and ecosystem benefits were combined and converted into monetary units to calculate the NEP per 1 kg of milk. The results indicated that semi-confined systems had the worst environmental performance (90 % more impacts) compared to the compost barn milk system. On the other hand, confined systems generate few ES benefits, but their environmental impacts were lower for most LCA impact categories (up to 87 % minimized impacts) compared to semi-confined systems. Finally, we concluded the confined systems in SP and PR showed the best NEP (1.07 and 1.48) aiming for both environmental impacts and ES benefits to fit the win–win situation.

Exploring the Feasibility of Quantum-Based Secure Communications for Nuclear Applications

Recent advancements in reactor designs could offer new revolutionary capabilities, including remote monitoring, increased flexibility, and reduced operation and maintenance costs. Embracing new digital technologies would allow for operational concepts such as semiautonomous or near-autonomous control, and two-way communications for real-time integration with the upcoming smart electric grid. However, such continuous data transmission from and toward a reactor site could potentially introduce new challenges and vulnerabilities, necessitating the prioritization of cybersecurity. Conventional information technology–based encryption schemes, which rely mostly on computational complexity, have been shown to be vulnerable to cyberattacks. With the advent of quantum computing, practically any asymmetric encryption could be potentially compromised. For example, it has been shown that a RSA-2048 bit key could be broken in 8 h. To address this challenge, we explore the feasibility of quantum key distribution (QKD) to secure communications. QKD is a physical layer security scheme relying on the laws of quantum mechanics instead of mathematical complexity. QKD promises not only unconditional security but also detection of potential intrusion, as it allows the communication parties to become aware of eavesdropping. To test the proposed hypothesis, a novel simulation tool (NuQKD) was developed to allow for real-time simulation of the BB84 QKD protocol between two remote terminals. A reference scenario is proposed, generic enough to cover various internal and external communication links to a reactor site. Using NuQKD, the internal and external data links were modeled, and receiver operating characteristic curves were calculated for various QKD configurations. A performance analysis was conducted, demonstrating that QKD can provide adequate secret key rates with low false alarms and has the potential of addressing the nuclear industry’s high standards of confidentiality for distance lengths up to 75 km of fiberoptics. Using a conservative estimation, QKD can provide up to 21.5 kbps of secret key rate for a distance of 1 km and 14.4 kbps at 10 km. The target secret key rates for the corresponding links were estimated at 16 kbps and 80 bps, respectively, based on the analysis of real data from a PUR-1 fully digital reactor. Consequently, QKD is shown to be compatible with existing and future point-to-point reactor communication architectures. These results motivate further study of quantum communications for nuclear reactors.

Optimizing air quality and health Co-benefits of mitigation technologies in China: An integrated assessment

Carbon mitigation technologies lead to air quality improvement and health co-benefits, while the practical effects of the technologies are dependent on the energy composition, technological advancements, and economic development. In China, mitigation technologies such as end-of-pipe treatment, renewable energy adoption, carbon capture and storage (CCS), and sector electrification demonstrate significant promise in meeting carbon reduction targets. However, the optimization of these technologies for maximum co-benefits remains unclear. Here, we employ an integrated assessment model (AIM/enduse, CAM-chem, IMED|HEL) to analyze air quality shifts and their corresponding health and economic impacts at the provincial level in China within the two-degree target. Our findings reveal that a combination of end-of-pipe technology, renewable energy utilization, and electrification yields the most promising results in air quality improvement, with a reduction of fine particulate matter (PM2.5) by −34.6 μg m−3 and ozone by −18.3 ppb in 2050 compared to the reference scenario. In contrast, CCS technology demonstrates comparatively modest improvements in air quality (−9.4 μg m−3 for PM2.5 and −2.4 ppb for ozone) and cumulative premature deaths reduction (−3.4 million from 2010 to 2050) compared to the end-of-pipe scenario. Notably, densely populated regions such as Henan, Hebei, Shandong, and Sichuan experience the most health and economic benefits. This study aims to project effective future mitigation technologies and climate policies on air quality improvement and carbon mitigation. Furthermore, it seeks to delineate detailed provincial-level air pollution control strategies, offering valuable guidance for policymakers and stakeholders in pursuing sustainable and health-conscious environmental management.

Investigation on cellular LTE C-V2X network serving vehicular data traffic in realistic urban scenarios

The need for reliable vehicular communication is an essential precondition of future Cooperative Intelligent Transportation Systems (C-ITS). The C-ITS applications and their diverse requirements necessitate a hybrid approach that combines ad hoc and cellular networks to support seamless and robust connectivity. While the research showed tremendous potential, the successful adaptation of the hybrid approach depends on the optimal understanding of its impact on network and protocol performance in an actual reference scenario. This work, which has practical implications for the field, focuses on creating a realistic representation of the dual-link-enabled Hybrid Vehicular Network (HVN) in the simulator. Several enhancements were implemented into a network simulator, including multiple Radio Access Technologies (multi-RAT) support, models for path loss predictions, static subscribers, background interference, and SINR throughput mapping within a multi-cell environment. We then presented a parameterized data traffic steering algorithm that enables switching between Dedicated Short-Range Communication (DSRC) and Long Term Evolution (LTE) RAT based on channel congestion and cell load conditions. The simulation result shows the high potential of a dual-link-enabled hybrid approach and its implications on both networks under realistic vehicular networking conditions. The investigations reveal that an intelligent decision to steer traffic can target balanced connectivity and highly reliable vehicular communication at a reduced network load.

Integrated CO2 capture and conversion into methanol units: Assessing techno-economic and environmental aspects compared to CO2 into SNG alternative

Using carbon dioxide (CO2) as a raw-material to produce value-added chemicals has a strategic role to play in the decarbonization of energy resources and the transition to a climate-neutral economy. E-methanol, Synthetic Natural Gas (SNG) and e-kerosene are one of the most promising pathways to convert CO2. In this context, the aim of this work is to propose an optimized and integrated CO2 to methanol process and then to compare it to the CO2 to SNG process from economic and environmental points of views. An optimized reactor configuration in the CO2 to methanol conversion unit has been successfully implemented in Aspen Plus® and leads to a thermal energy self-sufficiency of this unit. A heat integration with an advanced capture unit has been performed where 5 % of the heat requirement could be provided from the conversion unit while 95 % come from external steam source. Techno-economic assessment of the optimized process showed that methanol is more profitable when it is used as a raw material to synthetize other chemicals. As an energy carrier, SNG is more interesting. Compared to the reference scenario, a net CO2 emission reduction of 70 % in the CO2 to SNG route and of 60 % in the CO2 to methanol route were obtained. Concerning the fossil depletion impact, in both cases, a reduction of more than 60 % was noticed (ca. 75 % in CO2 to SNG route and 61 % in CO2 to methanol case).

Military education. A look from security and defense

The education, in the military environment, has different looks for its analysis. Among the possible focuses, they are the aspects of security and defense, being these the spine of the military forces. Starting from an analysis regarding the security and defense in the field of the military education, and applied to the Colombian national context, the present study had as objective to meditate on the formation of the military one, taking as reference scenario the military teaching in the aerospace formation, in a specific way: the Military School of Aviation (EMAVI) and the School of Posgraduate of the Colombian Aerospace Force (EPFAC). In that way, together to the analysis of bibliographical sources on the thematic one, the article presents general considerations on the topic of the security and the defense, followed by a look to the national internal conflict and the experience in the aviator's formation at the present time.

Climate change impacts on the within-country income distributions

This paper investigates the relationship between climate change and income inequality, recognizing that the economic impacts of climate change are not uniform across different levels of income within and across countries. Using methods from the existing literature on climate and economic growth, we analyze the economic impact of rising temperatures by within-country income decile. Our findings suggest that climate change disproportionately affects the poorer segments of the population within countries, even after accounting for a country’s ability to adapt to climate impacts, while richer households suffer lower damages. In the reference scenario without additional climate action (3.6°C warming), we estimate that climate impacts could lead to an increase in the Gini index by up to six percentage points, notably in Sub-Saharan Africa. We project impacts to 2100 through the RICE50+ model and estimate the income elasticity of impacts within countries. Our estimates indicate that climate change damages are regressive, with an income elasticity of damages of 0.6 under our preferred specification. On the other hand, climate benefits are approximately distribution-neutral or slightly progressive.

Modelling policy scenarios: refocussing the model-policy logic for the case of German passenger transport

BackgroundNational energy and climate scenarios are typically simulated or optimised using sectoral or energy system models, which include a large number of model settings and scenario assumptions. However, their realisation is contingent upon framework conditions and policy settings, which are often included in accompanying narrative scenarios. This paper therefore proposes refocussing the model-policy logic towards directly modelling policy effects. Applying this approach to the case of German passenger transport, I focus on demand-side policies and use open-source databases and models to develop a module for the translation of policies into model parameters.ResultsSeparate model runs were used to test a ceteris paribus policy reference scenario for 2035, the marginal impacts of modelled single policy effects, and a joint policy package scenario. Relative to the reference, demand-side policies show significant impacts: an annual reduction of 355 bn person-kilometres (30%) and a reduction of car-owning households from 95 to 90% in rural areas and from 76 to 64% in urban areas. The resulting mode shift decreases car-driven kilometres by 400 bn and increases public transport by 45 bn per year. This may reduce GHG emissions by an additional 30 Mt (or 33%) relative to the reference in 2035.ConclusionsTransport demand policies can significantly mitigate GHG, calling for a stronger policy focus beyond the much-studied shift to electric vehicles. While further research and model development are needed, the feasibility of policy scenario modelling increases its utility for policy-making.

Large differences between observed and expected Ecuadorian deforestation from 2001 to 2009: a counterfactual simulation approach

Ensuring the integrity of the world’s forests is indispensable for mitigating climate change, combatting biodiversity loss, and protecting the livelihoods of rural communities. While many strategies have been developed to address deforestation across different geographic scales, measuring their impact against a fluctuating background of market-driven forest loss is notoriously challenging. In this article, we (1) asses deforestation in Ecuador using a dynamic, counterfactual baseline that excludes non-market factors, (2) identify periods of reduced and excess deforestation, and (3) assess the economic consequences of associated CO2 emissions using the social cost of carbon metric. We construct a counterfactual market-forces-only reference scenario by simulating heterogeneous profit-seeking agents making satisficing land-use allocation decisions under uncertainty. The model simulates a reference scenario for 2001–2022, a period encompassing dollarization, the beginning of a constitution granting inalienable rights to nature, and the launch of the largest payments for ecosystem services program in Ecuador’s history. On this period, total deforestation was approximately 20% lower than expected in a market-forces-only scenario (9540 vs.12,000 km2). The largest deviation occurred in 2001–2009, when observed deforestation was 43.6% lower than expected (3720 vs 6590 km2). From 2010 onwards, deforestation appears to be market-driven. We assess the economic value of avoided CO2 emissions at US $5.7 billion if the reduction is permanent, or US $3.1 billion considering a 1% risk of loss from 2022 onwards. We discuss contributing factors that likely shaped periods of reduced and excess deforestation and stress the need to use realistic baselines.

Future role of wave power in Seychelles: A structured sensitivity analysis empowered by a novel EnergyPLAN-based optimisation tool

Mitigating climate change requires a variety of energy technologies and energy simulation approaches to evaluate the best possible system structures. Screening whether novel technologies are a viable solution for a particular country within a cost-optimised system setup is usually simulation- and time-intensive. This study introduces the novel add-on optimisation tool EP-ALISON-LUT for use in combination with EnergyPLAN applied to the test case of wave power in the case of Seychelles in 2030 and 2050 within a structured sensitivity analysis. The tool enables a high number of possible system setups and scenarios, including the import and domestic production of electricity-based fuels, to be modelled, allowing for an in-depth view of the system impacts of integrating wave power. The results indicate a limited role for wave power due to its relatively low yield, especially in 2030. However, in 2050, up to 500 MW of wave power capacity is possible with a lower or similar levelised cost of final energy compared to the reference scenario in 2019, which can benefit the diversification of the power generation portfolio. Thus, this novel tool is fast and effective in technology screening studies requiring a fast optimisation algorithm.

Uncovering secret neutrino interactions at tau neutrino experiments

We investigate the potential of future tau neutrino experiments for identifying the ντ appearance in probing secret neutrino interactions, which is very important in a variety of fields, such as neutrino physics, dark matter physics, grand unified theories, astrophysics, and cosmology. The reference experiments include the DUNE far detector utilizing the atmospheric data, which is for the first time probing secret interactions, the Forward Liquid Argon Experiment (FLArE100) detector at the Forward Physics Facility, and emulsion detector experiments such as SND@LHC, FASERν, AdvSND, FASERν2, and SND@SHiP. For concreteness, we consider a reference scenario in which the hidden interactions among the neutrinos are mediated by a single light gauge boson Z′ with a mass at most below the sub-GeV scale and an interaction strength gαβ between the active neutrinos να and νβ. We confirm that these experiments have the capability to significantly enhance the current sensitivities on gαβ for mZ′≲500 MeV due to the production of high-energy neutrinos and excellent ability to detect tau neutrinos. Our analysis highlights the crucial role of “downward-going” DUNE atmospheric data in the search for secret neutrino interactions because of the rejection of backgrounds dominated in the upward-going events. Specifically, ten years of DUNE atmospheric data can provide the best sensitivities on geτ and gμτ which are about 2 orders of magnitude improvement. In addition, the beam-based experiments such as FLArE100 and FASERν2 can improve the current constraint on geτ and gμτ by more than an order of magnitude after the full running of the high luminosity LHC with the integrated luminosity of 3 ab−1. For geμ and gee the SHiP experiment can play the most important role in the high-energy region of mZ′>few 100 MeV, and FLArE100 and FASERν2 can set the most stringent constraints for mZ′ less than few keV, in particular, if atmospheric flux uncertainty reduces DUNE sensitivity. Although our analysis is proceeded under our reference scenario of secret Z′, our analysis strategies can be readily applicable to other types of secret interactions such as Majoron models. Published by the American Physical Society 2024

A New Model for the Planetary Radiation Pressure Acceleration for Solar Sails

Solar sailing is a propulsion method that takes advantage of solar radiation pressure to generate thrust. Although most of near-future solar-sail missions will fly in low Earth orbit, where planetary radiation pressure can be as large as 20% of solar radiation pressure, studies on the accelerations produced by the Earth’s albedo and blackbody radiation have only been conducted to a very limited first-order extent. This paper therefore provides a novel, detailed analytical model for these perturbing accelerations, valid for perfectly reflecting solar sails. The full derivation of the model is described, and a thorough analysis of the blackbody and albedo radiation pressure accelerations is conducted for different orbital conditions. Then, to determine the model’s accuracy, a comparison with the state of the art (the finite-disk radiation source model and a high-fidelity numerical model) is provided. Ultimately, different analyses to quantify the effect of planetary radiation pressure acceleration on the solar-sail maneuvering capabilities are presented, using NASA’s upcoming ACS3 mission as reference scenario. The results highlight the nonnegligible effect of uncontrolled planetary radiation pressure acceleration, which can reduce the sailcraft’s achievable altitude and inclination gains to 76 and 80%, respectively, of the gains obtained when planetary radiation pressure is not accounted for.