Nitrogenase is the only enzyme that can convert N2 to NH3. Crystallographic structures have indicated that one of the sulfide ligands of the active-site FeMo cluster, S2B, can be replaced by an inhibitor, like CO and OH−, and it has been suggested that it may be displaced also during the normal reaction. We have investigated possible proton transfer pathways within the FeMo cluster during the

In this paper, the most important results are presented and discussed from a multiyear interdisciplinary study directed toward the identification of the most suitable glass/polymer composite systems with the highest resistance to brittle fracture for high voltage composite insulator applications. Several unidirectional glass/polymer composite systems, commonly used in composite insulators, based e

It was postulated in [1], based on experimental evidence, that brittle fracture failures of composite (non-ceramic) HV insulators could be caused by water and mechanical stresses. It was also claimed therein that the brittle fracture process was more likely to happen with water than acids. This postulation could be of major importance as its ramifications might affect the entire composite insulato

This paper describes water diffusion into and electrical testing of unidirectional glass reinforced polymer (GRP) composite rods used as load bearing components in high voltage composite (non-ceramic) insulators. The tests were performed following ANSI standard C29.11 Section 7.4.2 that can be used to evaluate electrical properties of composites. The unidirectional composite rod materials based on

The mechanical response of a woven eight-harness satin graphite/polyimide composite has been investigated by performing ± 45° tensile and Iosipescu shear tests at room temperature. Nonlinear finite element simulations of the tests have been conducted to determine internal stress distributions in the ±45° tensile and Iosipescu fabric specimens as a function of load. In the experimental part of this

The purpose of this research is to determine the resistance to stress-corrosion cracking (SCC) of three unidirectional (pultruded) E-glass/polymer composites based on modified polyester, epoxy and vinyl ester resins. The composites have been subjected to a nitric acid solution of pH 1.2 in a newly designed four-point bend fixture. The stress-corrosion process was initiated on the as-supplied surfa

• The Arctic is continuing to warm faster than any other region on Earth, but key uncertainties remain in our knowledge of the Arctic carbon cycle. • We review the most current knowledge pertaining to estimates of arctic greenhouse gas components and discuss uncertainties associated with these measurements and models. • While the Arctic Ocean is consistently estimated as a carbon sink, we have yet

Being integral to the fossil-based energy order and as a key driver of multiple and intersecting ecological crises, the petrochemical industry faces increasing pressures to transform. This paper examines how major petrochemical companies navigate these pressures. Drawing from literatures on discursive power, narratives, and neo-Gramscian political economy, we introduce the concept of narrative rea

Individuals who sleep poorly report spending more time mind wandering during the day. However, past research has relied on self-report measures of sleep or measured mind wandering during laboratory tasks, which prevents generalization to everyday contexts. We used ambulatory assessments to examine the relations between several features of sleep (duration, fragmentation, and disturbances) and mind

Importance: National Institute on Aging-Alzheimer's Association (NIA-AA) workgroups have proposed biological research criteria intended to identify individuals with preclinical Alzheimer disease (AD). Objective: To assess the clinical value of these biological criteria to identify older individuals without cognitive impairment who are at near-term risk of developing symptomatic AD. Design, Setting

Values play an important role in how we understand, make sense of, and tackle crises. They influence how we frame the problems that crisis management is supposed to address, and how we choose the instruments for that. The EGE points to the importance of human dignity and solidarity being at the core of crisis management, with processes of deliberation that make values explicit. It shows how public

The chemical environment responsible for the brittle fracture failure of composite (non-ceramic) insulators is determined. Also previously reported observations by the authors are verified. Five non-ceramic composite suspension insulators and one composite guide were subjected to FTIR analysis. Out of the six field failed units, five insulators showed significant levels of nitrate on their brittle

Water is an urgent topic of research in cultural and feminist geographies. Geographers study water through interdisciplinary approaches including critical resource geography, political ecology, and feminist theory. An emerging area of research within cultural and feminist geography considers the affective, emotional qualities of water as part of water’s social and political ramifications. Methodol

There is a need for consensus on the recommendations for follow-up of children and adolescents with celiac disease. Objectives: To gather the current evidence and to offer recommendations for follow-up and management. Methods: The Special Interest Group on Celiac Diseases of the European Society of Paediatric Gastroenterology Hepatology and Nutrition formulated ten questions considered to be essen

Objective: Aberrant activity of androgen receptor (AR) is the primary cause underlying development and progression of prostate cancer (PCa) and castration-resistant PCa (CRPC). Androgen signaling regulates gene transcription and lipid metabolism, facilitating tumor growth and therapy resistance in early and advanced PCa. Although direct AR signaling inhibitors exist, AR expression and function can

Vaccination to prevent influenza virus infection and to lessen its severity is recommended among healthcare workers (HCWs). Health professionals have a higher risk of exposure to viruses and could transmit the influenza virus to vulnerable patients who are prone to severe disease and mortality. The aim of the current study was to evaluate the levels of influenza vaccine acceptance and uptake as we

Organic waste forms a big share of municipal solid waste, especially in developing countries. Its management is however faced with many challenges ranging from limited financial and technical capacity to lack of, or weak policy enforcement. This causes poor management of the waste leading to open dumping and disposal in un-engineered landfills. Such practices have adverse effects on both the envir

The current reality is that cities are losing green spaces rather than creating more of them, leading to many urban challenges. Urban nature-based solutions (NbS), through renaturing urban landscapes, are seen as a promising solution to help cities deal with climate change and build a better future for communities worldwide. In Europe, specifically, NbS is also seen as a way of boosting green innov