93 research outputs found
Exsolution-enhanced reverse water-gas shift chemical looping activity of Sr2FeMo0.6Ni0.4O6-δ double perovskite
This study investigates the structural evolution and redox characteristics of the double perovskite Sr2FeMo0.6Ni0.4O6-delta (SFMN) during hydrogen (H2) and carbon dioxide (CO2) redox cycles and explores the material performance in the Reverse Water-Gas Shift Chemical Looping (RWGS-CL) reaction. In-situ and ex-situ X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM) studies reveal that H2 reduction at temperatures above 800 degrees C leads to the exsolution of bimetallic Ni-Fe alloy particles and the formation of a Ruddlesden-Popper (RP) phase. A core-shell structure with Ni-Fe core and a perovskite oxide shell is formed with subsequent redox cycles, and the resulting material exhibits better performance and high stability in the RWGS-CL process. Thermogravimetric (TGA) and Temperature Programmed Reduction (TPR) and Oxidation (TPO) analyses show that the optimal reduction and oxidation temperatures for maximizing the CO yield are around 850 degrees C and 750 degrees C respectively, and that the cycled material is able to work steadily under isothermal conditions at 850 degrees C
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Addressing Challenges in Long-Term Strategic Energy Planning in LMICs: Learning Pathways in an Energy Planning Ecosystem
This paper presents an innovative approach to addressing critical global challenges in long-term energy planning for low- and middle-income countries (LMICs). The paper proposes and tests an international enabling environment, a delivery ecosystem, and a community of practice. These components are integrated into workflows that yield four self-sustaining capacity-development outcomes. Planning long-term energy strategies in LMICs is particularly challenging due to limited national agency and poor international coordination. While outsourcing energy planning to foreign experts may appear to be a viable solution, it can lead to a reduction in government agency (the ability of a government to make its own informed analysis and decisions). Additionally, studies commissioned by external experts may have conflicting terms of reference, and a lack of familiarity with local conditions can result in misrepresentations of on-the-ground realities. It is argued here that enhancing national agency and analytical capacity can improve coordination and lead to more robust planning across line ministries and technical assistance (TA) providers. Moreover, the prevailing consulting model hampers the release and accessibility of underlying analytics, making it difficult to retrieve, reuse, and reconstruct consultant outputs. The absence of interoperability among outputs from various consultants hinders the ability to combine and audit the insights they provide. To overcome these challenges, five strategic principles for energy planning in LMICs have been introduced and developed in collaboration with 21 international and research organizations, including the AfDB, IEA, IRENA, IAEA, UNDP, UNECA, the World Bank, and WRI. These principles prioritize national ownership, coherence and inclusivity, capacity, robustness, transparency and accessibility. In this enabling environment, a unique delivery ecosystem consisting of knowledge products and activities is established. The paper focuses on two key knowledge products as examples of this ecosystem: the open-source energy modeling system (OSeMOSYS) and the power system flexibility tool (IRENA FlexTool). These ecosystem elements are designed to meet user-friendliness, retrievability, reusability, reconstructability, repeatability, interoperability, and audibility (U4RIA) goals. To ensure the sustainability of this ecosystem, OpTIMUS is introduced—a community of practice dedicated to maintaining, supporting, expanding, and nurturing the elements within the ecosystem. Among other ecosystem elements, training and research initiatives are introduced, namely the Energy Modelling Platform for Africa, Latin America and the Caribbean, and Asia-Pacific as well as the ICTP Joint Summer School on Modelling Tools for Sustainable Development. Once deployed via workflows, the preliminary outcomes of these capacity-development learning pathways show promise. Further investigation is necessary to evaluate their long-term impacts, scalability, replication, and deployment costs
Towards evidence-based policymaking: energy modelling tools for sustainable development
Governments’ commitments to cope with climate change unpredictability, while ensuring an equal green transition, require clear plans to allocate resource better and estimate the impact of energy and social policies. Many energy models were developed to reach these goals. One of these is the Open Source Modelling System (OSeMOSYS), which uses the graphical Model Management Interface (MoManI). Feedback from MoManI users has shown unpleasant experiences and a steeper learning curve than desirable. In this study, the Simple And Nearly Done (CCG-SAND) Interface was developed to investigate whether an Excel-based tool could fasten and strengthen the process of evidence-based policymaking, reaching a wider audience of energy modelling practitioners. The potential improvements of CCG-SAND Interface compared to MoManI were tested and validated with an introductory Master course teaching exercise called Climate, Land, Energy and Water Systems for OSeMOSYS (CLEWS-O), four Master students from Imperial College London used CCG-SAND Interface for their energy
models of Laos, Kenya, Nigeria, and Vietnam. To ensure a standardized collection and manipulation of data, replicable energy systems formats were created, respectively, for simple and more detailed analysis (Tier 1 and Tier 2 Models). Moreover, a case study on Uganda was analysed, including the validation of national energy policies which aim at diversifying the energy mix and reducing indoor pollution from the cooking applications of inefficient stoves. Analysis of the results obtained for the Ugandan case study showed massive enhancements of the quality of life if Improved Biomass and Electric Stoves are used. The results also indicated that the proposed electricity generation policy is not cost-effective. A revision of this plan could aim at reducing the dependency from nuclear energy. On these bases, CCG-SAND Interface proved to be a valuable and user-friendly tool for long-term energy policy modelling. Future work could aim at automatizing some processes of CCG-SAND Interface and reduce the computational time. Finally, CCG-SAND Interface has the potential to replace MoManI in
universities Master programmes
Early Cervical Cancer and Recurrence after Minimally Invasive Surgery without Uterine Manipulator
Objective: Worldwide cervical cancer is the fourth most common cancer and is also the fourth leading cause of death among women, after breast cancer, colorectal cancer, and lung cancer. The aim of this study is to investigate the long-term oncological safety of laparoscopic treatment without the use of a uterine manipulator for patients with early stage cervical cancer. Materials and methods: A single-center retrospective study was conducted at the Department of Obstetrics and Gynecology of ARNAS Garibaldi Nesima on patients surgically treated for early cervical cancer from 2014 to 2017. Inclusion criteria included squamous or adenosquamous histotype, FIGO stage from Ia1 to Ib2, cancer size Results: Seventy patients were identified, but only thirty-one met the inclusion criteria and were enrolled. All patients underwent surgery: three patients with the uterine manipulator, twenty-eight without. Among the thirty-one patients enrolled, twelve women had cancer in situ (IA1), nineteen had an early stage cervical cancer, in particular two cases of cervical cancer stage IA2, ten cases of cervical cancer stage IB1, and seven cases of cervical cancer stage IB2, according to the FIGO classification. At follow-up, three cases of recurrence occurred, but the uterine manipulator was not used. Conclusion: After five years of follow-up, recurrence rates in patients treated with minimally invasive surgery are about 10%, but the use of a uterine manipulator is not related to a higher level of recurrence rates
Early Cervical Cancer and Recurrence after Minimally Invasive Surgery without Uterine Manipulator
Objective: Worldwide cervical cancer is the fourth most common cancer and is also the fourth leading cause of death among women, after breast cancer, colorectal cancer, and lung cancer. The aim of this study is to investigate the long-term oncological safety of laparoscopic treatment without the use of a uterine manipulator for patients with early stage cervical cancer. Materials and methods: A single-center retrospective study was conducted at the Department of Obstetrics and Gynecology of ARNAS Garibaldi Nesima on patients surgically treated for early cervical cancer from 2014 to 2017. Inclusion criteria included squamous or adenosquamous histotype, FIGO stage from Ia1 to Ib2, cancer size < 4 cm, ECOG status 0–1, and negative serum beta-HCG. The patients were divided into two groups: treatment with and without an intra-uterine manipulator. Results: Seventy patients were identified, but only thirty-one met the inclusion criteria and were enrolled. All patients underwent surgery: three patients with the uterine manipulator, twenty-eight without. Among the thirty-one patients enrolled, twelve women had cancer in situ (IA1), nineteen had an early stage cervical cancer, in particular two cases of cervical cancer stage IA2, ten cases of cervical cancer stage IB1, and seven cases of cervical cancer stage IB2, according to the FIGO classification. At follow-up, three cases of recurrence occurred, but the uterine manipulator was not used. Conclusion: After five years of follow-up, recurrence rates in patients treated with minimally invasive surgery are about 10%, but the use of a uterine manipulator is not related to a higher level of recurrence rates
Meningioma in the third trimester of pregnancy: A case report
Meningiomas are rare benign tumors during pregnancy. They can put both the mother and the fetus at risk because rapid changes in size may occur. The study reports a case of olfactory groove meningioma in a 34-year-old pregnant woman with visual impairment, anosmia, and dysgeusia that increased in severity during the 29th week of gestation. Magnetic resonance imaging showed an olfactory groove meningioma. The patient underwent a preterm cesarean section to avoid the worsening of the clinical condition due to intracranial compression phenomena. A computed tomography scan of the brain supported the diagnosis. The surgical intervention occurred on the third day after delivery. The clinical course was uneventful and the chiasmal syndrome improved in the following 2Â months. Meningiomas in pregnancy may present unique challenges and have a wide array of clinical presentations. Management of maternal meningiomas can be complex and requires a multidisciplinary approach. The treatment decision largely depends on the size and location of the tumor, the presence of symptoms, gestational age, and fetal well-being. Further research is needed to enhance the understanding of the underlying mechanisms and improve management approaches for this rare condition
Evidence-based policymaking: Insights and recommendations for the implementation of clean energy transition pathways for Kenya’s power sector
With ambitious targets to drastically increase economic activity over the next decade, Kenya’s future is undoubtedly energy-intensive. Current power capacity expansion plans will see Kenya considerably ramp up fossil fuel generation, significantly increasing emissions. Therefore, Kenya is at a crucial stage of its national development, with critical decisions to make regarding its future power expansion and production. OSeMOSYS modelling software (clicSAND version v1.1) is employed to produce a series of possible clean energy transition pathways to increase renewable power production under rapidly intensifying demand. This study integrates existing national priorities and policies into six modelled scenarios to provide insights into their generation, total production, and costs, which can assist future policymaking and capacity-building efforts. The high-level insights gained in this research were employed to suggest key recommendations for Kenya’s power sector. Most notably, policy alignment, increased wind power production, energy-efficiency penetration, finance and investment securement, the development of storage technologies, power transmission, and distribution improvements should be prioritised.</p
Techno-economic dataset and assumptions for long-term energy systems modelling in the Dominican Republic (2024–2050)
The land transport sector, impacting fossil fuel consumption, has been selected as one of the sectors to apply decarbonization strategies. Energy systems modelling is an applied tool to evaluate scenarios and strategies that can be implemented in the transport sector to achieve energy transitions. These energy modelling tools need a dataset that allows the simulation of alternative scenarios of the systems. For this purpose, a collection and processing of technical-economic data is needed to ensure a quality input for simulation tools. This article presents a set of open data to create a model of the energy system of the Dominican Republic to assess alternative scenarios and develop strategies to achieve the energy transition in the land transport sector. This exercise is performed to support the energy planning policies of the country. Although the dataset is presented for the conditions of the Dominican Republic, the insight regarding data gathering and processing can be applied to other island countries. The data obtained are an open-access database of energy regulators, generation agents, and representatives of the generation, transmission, and distribution sector, as well as websites, databases of international organizations, scientific journals, and standards. Therefore, the data presented can be updated as the technical-economic information becomes public
Designing a zero-order energy transition model: How to create a new Starter Data Kit
The Paris Agreement was signed by 192 Parties, who committed to reducing emissions. Reaching such commitments by developing national decarbonisation strategies requires significant analyses and investment. Analyses for such strategies are often delayed due to a lack of accurate and up-to-date data for creating energy transition models. The Starter Data Kits address this issue by providing open-source, zero-level country datasets to accelerate the energy planning process. There is a strong demand for replicating the process of creating Starter Data Kits because they are currently only available for 69 countries in Africa, Asia, and South America. Using an African country as an example, this paper presents the methodology to create a Starter Data Kit made of tool-agnostic data repositories and OSeMOSYS-specific data files. The paper illustrates the steps involved, provides additional information for conducting similar work in Asia and South America, and highlights the limitations of the current version of the Starter Data Kits. Future development is proposed to expand the datasets, including new and more accurate data and new energy sectors. Therefore, this document provides instructions on the steps and materials required to develop a Starter Data Kit. • The methodology presented here is intended to encourage practitioners to apply it to new countries and expand the current Starter Data Kits library. • It is a novel process that creates data pipelines that feed into a single Data Collection and Manipulation Tool (DaCoMaTool). • It allows for tool-agnostic data creation in a consistent format ready for a modelling analysis using one of the available tools
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