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Proton exchange membrane water electrolysis is a promising technology to produce green hydrogen from renewables, as it can efficiently achieve high current densities. Lowering iridium amount in oxygen evolution reaction electrocatalysts is critical for achieving cost-effective production of green hydrogen. In this work, we develop catalysts from Ir double perovskites. Sr 2 CaIrO 6 achieves 10 mA cm −2 at only 1.48 V. The surface of the perovskite reconstructs when immersed in an acidic electrolyte and during the first catalytic cycles, resulting in a stable surface conformed by short-range order edge-sharing IrO 6 octahedra arranged in an open structure responsible for the high performance. A proton exchange membrane water electrolysis cell is developed with Sr 2 CaIrO 6 as anode and low Ir loading (0.4 mg Ir cm −2 ). The cell achieves 2.40 V at 6 A cm −2 (overload) and no loss in performance at a constant 2 A cm −2 (nominal load). Thus, reducing Ir use without compromising efficiency and lifetime. While water splitting offers a renewable means to produce H 2 fuel, most electrolyzers rely on scarce elements to function. Here, authors study low-content Iridium catalysts derived from mixed oxides for proton exchange membrane water electrolysis anodes without compromising activity and durability.

\"The global economic crisis of 2008-2009 exposed systemic failings at the core of economic policy making worldwide. The crisis came on top of several other crises, including skyrocketing and highly volatile world food and energy prices and climate change. This book argues that new policy approaches are needed to address such devastating global development challenges and to avoid the potentially catastrophic consequences to livelihoods worldwide that are likely to result from present approaches. The contributors to the book are independent development experts, brought together by the UN Commiittee for Development Policy, an advisory body of the Economic and Social Council, to identify a development strategy capable of promoting a broad-based economic recovery and at the same time guaranteeing social equity and environmental sustainability both within countries and internationally. This new development approach seeks to promote the reforms needed to improve global governance, providing a more equitable distribution of global public goods. The contributors offer a critical evaluation of past development experiences and report on their creative search for new and well-thought out answers for the future. They suggest that economic progress, fairer societies and environmental sustainability can be compatible objectives, but only when pursued simultaneously by all.\"--Page 4 of cover.

Signature-based Intrusion Detection Systems (SIDS) play a crucial role within the arsenal of security components of most organizations. They can find traces of known attacks in the network traffic or host events for which patterns or signatures have been pre-established. SIDS include standard packages of detection rulesets, but only those rules suited to the operational environment should be activated for optimal performance. However, some organizations might skip this tuning process and instead activate default off-the-shelf rulesets without understanding its implications and trade-offs. In this work, we help gain insight into the consequences of using predefined rulesets in the performance of SIDS. We experimentally explore the performance of three SIDS in the context of web attacks. In particular, we gauge the detection rate obtained with predefined subsets of rules for Snort, ModSecurity and Nemesida using seven attack datasets. We also determine the precision and rate of alert generated by each detector in a real-life case using a large trace from a public webserver. Results show that the maximum detection rate achieved by the SIDS under test is insufficient to protect systems effectively and is lower than expected for known attacks. Our results also indicate that the choice of predefined settings activated on each detector strongly influences its detection capability and false alarm rate. Snort and ModSecurity scored either a very poor detection rate (activating the less-sensitive predefined ruleset) or a very poor precision (activating the full ruleset). We also found that using various SIDS for a cooperative decision can improve the precision or the detection rate, but not both. Consequently, it is necessary to reflect upon the role of these open-source SIDS with default configurations as core elements for protection in the context of web attacks. Finally, we provide an efficient method for systematically determining which rules deactivate from a ruleset to significantly reduce the false alarm rate for a target operational environment. We tested our approach using Snort’s ruleset in our real-life trace, increasing the precision from 0.015 to 1 in less than 16 h of work.

This volume examines the theoretical and empirical landscape of social entrepreneurship in both non-profit and profit sectors. It extends the traditional view of social entrepreneurship to include the environmental and institutional factors that affect the emergence of social entrepreneurship activities, such as formal laws, regulations, procedures and informal institutions. The editors aim to provide evidence and increased understanding of this growing phenomenon. Social Entrepreneurship is gaining recognition as a key element of economic and social development. It embraces a wide set of situations with a broad scope of activities in for-profit and non-profit organizations interested in social performance and/or in economically profitable performance, with an emphasis on achieving social aim. In the strict sense, social entrepreneurship corresponds to entrepreneurs whose main concern is to achieve social objectives rather than to obtain personal financial profits. However, there is still much to be learned about the dynamics and processes of social entrepreneurship. The current literature in the field has tended to focus on psychological experiences and personal characteristics, or on organizational perspectives such as resources, capabilities and leadership. This book intends to provide theoretical frameworks and empirical studies to this very new and broad field. Specifically, this book provides a collection of contemporary research in the following topics: How to create opportunity through social innovation How to detect entrepreneurial opportunity to meet social needs How to develop social entrepreneurship, while still seeking profits How to discover opportunities for different forms of social entrepreneurship Featuring contributions from around the world, this book is a valuable source for students, academics, researchers, policy makers, and professionals in the area of social entrepreneurship.

The production of green hydrogen in water electrolyzers is limited by the oxygen evolution reaction (OER). State-of-the-art electrocatalysts are based on Ir. Ru electrocatalysts are a suitable alternative provided their performance is improved. Here we show that low-Ru-content pyrochlores (R 2 MnRuO 7 , R = Y, Tb and Dy) display high activity and durability for the OER in acidic media. Y 2 MnRuO 7 is the most stable catalyst, displaying 1.5 V at 10 mA cm −2 for 40 h, or 5000 cycles up to 1.7 V. Computational and experimental results show that the high performance is owed to Ru sites embedded in RuMnO x surface layers. A water electrolyser with Y 2 MnRuO 7 (with only 0.2 mg Ru cm −2 ) reaches 1 A cm −2 at 1.75 V, remaining stable at 200 mA cm −2 for more than 24 h. These results encourage further investigation on Ru catalysts in which a partial replacement of Ru by inexpensive cations can enhance the OER performance. Ru-pyrochlores find their way as alternative anodes of PEM water electrolyzers, and their high performance is owing to Ru sites embedded in RuMnO x surface layers. Here, a water electrolyser with Y 2 MnRuO 7 and only 0.2 mgRu cm −2 has been tested with significant durability.

Habitat loss is one of the most important threats to biodiversity; it alters the habitat connectivity of species and is among the main causes of the global amphibian extinction crisis. Identifying the potential areas of distribution and connectivity of species is of the utmost importance so that informed decisions can be made for the conservation of vulnerable amphibian populations. In this study, we performed species distribution models and used circuit theory to model omnidirectional connectivity for two plethodontid salamanders of conservation concern distributed in the forests of Chiapas, Mexico, and Guatemala (Bolitoglossa franklini and Bolitoglossa lincolni). Potential distribution maps show an affinity for well-preserved montane forests for both species. Likewise, we found that the niches of the species are not similar. The connectivity models show that the main areas of connectivity are in the Meseta Central de Chiapas, Sierra Madre de Chiapas, and the Cordillera Volcánica Guatemalense, in this last range, important areas of connectivity were located, as well as least-cost paths and barriers to the movement of both species. We identified that important areas of climatic suitability and connectivity are not within the protected natural areas and may be threatened by the increasing influence of anthropogenic activities. The results of our study show the importance of preserving the regional forests to ensure the persistence of species with arboreal habits and high sensitivity to habitat transformation, as well as to recognize and prioritize potential areas for management and protection in both southern Mexico and Guatemala.

All the magnetoelectric properties of scheelite-type DyCrO 4 are characterized by temperature- and field-dependent magnetization, specific heat, permittivity, electric polarization, and neutron diffraction measurements. Upon application of a magnetic field within ±3 T, the nonpolar collinear antiferromagnetic structure leads to a large linear magnetoelectric effect with a considerable coupling coefficient. An applied electric field can induce the converse linear magnetoelectric effect, realizing magnetic field control of ferroelectricity and electric field control of magnetism. Furthermore, a higher magnetic field (>3 T) can cause a metamagnetic transition from the initially collinear antiferromagnetic structure to a canted structure, generating a large ferromagnetic magnetization up to 7.0 μ B  f.u. −1 . Moreover, the new spin structure can break the space inversion symmetry, yielding ferroelectric polarization, which leads to coupling of ferromagnetism and ferroelectricity with a large ferromagnetic component. Magnetoelectric effect: Rare structure offers options for device control Researchers have isolated a material with remarkable electrical and magnetic properties that could simplify data manipulation in devices such as high-density memory platforms. Youwen Long from the Institute of Physics, Chinese Academy of Sciences in Beijing and colleagues report that synthesizing dysprosium chromate (DyCrO 4 ) under high pressure conditions produces a crystal with internal dipoles that respond to both magnetic and electric fields. Experiments demonstrated that magnetic field ordering of dipoles caused the material to emit a new electric output. Conversely, electric field alignment generated a large magnetic response over a wide temperature range. This magnetic output could be boosted even further by tweaking the initial dipole alignment with strong magnets. The team attributed the unusual magnetic and electric field control mechanisms to electronic interactions between dysprosium and chromium ions. The scheelite-type DyCrO 4 shows a large linear magnetoelectric effect (magnetic field induced electric polarization) as well as the converse effect (electric field induced magnetization) within ± 3 T. A higher magnetic field induces a metamagnetic transition from the initially collinear antiferromagnetic structure to a canted one, generating a giant ferromagnetic component by about 7 μB f.u. −1 . The new spin structure can break the spatial inversion symmetry and yield spontaneous ferroelectric polarization, giving rise to the coupling of ferromagnetism and ferroelectricity in a single-phase material.

Caffeic acid (CA) is a phenolic compound widely found in coffee beans with known beneficial effects in vivo. Many studies showed that CA has anti-inflammatory, anti-mutagenic, antibacterial and anti-carcinogenic properties, which could be linked to its antioxidant activity. Taking in consideration the reported in vitro antioxidant mechanism of other polyphenols, our working hypothesis was that the CA antioxidant activity could be related to its metal-chelating property. With that in mind, we sought to investigate the chemical antioxidant mechanism of CA against in vitro iron-induced oxidative damage under different assay conditions. CA was able to prevent hydroxyl radical formation promoted by the classical Fenton reaction, as determined by 2-deoxyribose (2-DR) oxidative degradation and DMPO hydroxylation. In addition to its ability to prevent hydroxyl radical formation, CA had a great inhibition of membrane lipid peroxidation. In the lipid peroxidation assays CA acted as both metal-chelator and as hydrogen donor, preventing the deleterious action promoted by lipid-derived peroxyl and alkoxyl radicals. Our results indicate that the observed antioxidant effects were mostly due to the formation of iron-CA complexes, which are able to prevent 2-DR oxidation and DMPO hydroxylation. Noteworthy, the formation of iron-CA complexes and prevention of oxidative damage was directly related to the pH of the medium, showing better antioxidant activity at higher pH values. Moreover, in the presence of lipid membranes the antioxidant potency of CA was much higher, indicating its enhanced effectiveness in a hydrophobic environment. Overall, our results show that CA acts as an antioxidant through an iron chelating mechanism, preventing the formation of free hydroxyl radicals and, therefore, inhibiting Fenton-induced oxidative damage. The chemical properties of CA described here--in association with its reported signaling effects--could be an explanation to its beneficial effects observed in vivo.

Metallum Fire-Resistant paint, denoted as MFR henceforth, represents a cutting-edge insulating material with dual functionality as a fireproof solution, presenting substantial advantages in the realm of construction applications. This exposition derives its primary insights from the scholarly contributions documented in publications. The focal point of these investigations includes the assessment of fire hazards associated with polyethylene materials in building structures and the enhancement of mortars in high-temperature environments in tunnels. The purpose of this study is to evaluate the effectiveness of a modified cork-based coating (MFR) compared to traditional coatings in terms of corrosion protection, fire resistance, and thermal insulation properties in construction applications. This evaluation focuses on quantifying the efficacy of MFR by examining key properties, such as adhesion, the reduced thickness required for fire protection, thermal conductivity reduction, and corrosion resistance under extreme environmental conditions. MFR is highly effective in fire prevention for buildings and tunnels, withstanding temperatures over 1000 °C while maintaining structural integrity. A unique aspect of MFR is its use of cork shavings, a typically underutilized byproduct from wine-bottle-stopper production. This innovative not only amplifies MFR’s fire-resistant attributes, but also introduces sustainability and judicious resource utilization into its manufacturing processes.