4,243 research outputs found
Resource Theory of Non-Revivals with Applications to Quantum Many-Body Scars
The study of state revivals has a long history in dynamical systems. We
introduce a resource theory to understand the use of state revivals in quantum
physics, especially in quantum many-body scarred systems. In this theory, a
state is said to contain no amount of resource if it experiences perfect
revivals under some unitary evolution. All other states are said to be
resourceful. We show that this resource bounds information scrambling.
Furthermore, we show that quantum many-body scarred dynamics can produce
revivals in the Hayden-Preskill decoding protocol and can also be used to
recover damaged quantum information. Our theory establishes a framework to
study information retrieval and its applications in quantum many-body physics.Comment: 7+19 page
Corrosion Behaviour of a Highly Alloyed Austenitic Alloy UB6 in Contaminated Phosphoric Acid
The influence of temperature (20-80°C) on the electrochemical behaviour of passive films anodically formed on UB6 stainless steel in phosphoric acid solution (5.5 M H3PO4) has been examined by using potentiodynamic curves, electrochemical impedance spectroscopy, and Mott-Schottky analysis. UB6 stainless steel in contaminated phosphoric acid is characterised by high interfacial impedance, thereby, illustrating its high corrosion resistance. The obtained results show that the films behave as n-type and p-type semiconductors in the potential range above and below the flat band potential, respectively. This behaviour is assumed to be the consequence of the semiconducting properties of the iron oxide and chromium oxide regions which compose the passive film
Envisioning carbon-smart and just urban green infrastructure
To address the inter-connected climate and biodiversity crises, it is crucial to understand how multifunctional urban green infrastructure (UGI) is perceived to contribute to carbon neutrality, biodiversity, human well-being, and justice outcomes in cities. We explore how urban residents, including youth, associate carbon-related meanings with multifunctional UGI and how these meanings relate to co-benefits to biodiversity, well-being, and broader sustainability outcomes. Our findings are based on a survey distributed among urban residents of Helsinki, Finland (n = 487) and reveal how carbon-related meanings of UGI manifest at different levels of abstraction, agency, and scale, and incorporate community values and concerns attributed to the planning, features, functions, and transformational dimensions of UGI. Core carbon-related meanings of UGI emphasize either actions towards sustainability, carbon neutrality, biodiversity, or unfamiliarity towards such meanings. Perceived justice concerns and the socio-demographic contexts of the respondents covaried with carbon-related meanings associated with UGI. The results illustrate community perceptions of how it is not only possible, but rather expected, that multifunctional UGI is harnessed to tackle climate change, human well-being, and biodiversity loss in cities. Challenges for implementing the carbon-related benefits of UGI include navigating the different expectations placed on UGI and including residents with diverse socio-economic backgrounds during the process. Our findings contribute to a holistic understanding of how multifunctional UGI can help bridge policy agendas related to carbon neutrality, biodiversity protection, and human well-being that cities can implement when aiming for sustainable, just, and socially acceptable transitions towards a good Anthropocene
Patient Perspective on the Management of Cancer Pain in Spain
Pain in cancer is often underdiagnosed and undertreated. Breakthrough pain, in particular, severely impacts the quality of life of patients. In this study, we evaluated management and care of pain in Spain from the patient perspective by assessing the experience of 275 patients who had suffered breakthrough pain. Although most patients had suffered moderate-to-severe pain in the last 24 hours, pain relief was achieved in the majority of cases. The body areas with a higher pain intensity was felt varied based on primary cancer. Adherence to treatment was subpar, and patients were moderately concerned about addiction to treatment and adverse events. Doctors did not assess pain in every visit and there is room for improvement in its classification. Education strategies directed toward patients and health care personnel are needed to improve pain assessment, follow-up, and compliance. These could guide shared decision-making and improve communication about cancer pain to improve its care
Association between anxiety and vascular dementia risk: new evidence and an updated meta-analysis
The association between anxiety and vascular dementia (VaD) is unclear. We aimed to reliably estimate the association between anxiety and VaD risk using meta-analysis to pool new results from a large community-based cohort (Zaragoza Dementia and Depression (ZARADEMP) study) and results from previous studies. ZARADEMP participants (n = 4057) free of dementia were followed up on for up to 12 years. Cases and subcases of anxiety were determined at baseline. A panel of four psychiatrists diagnosed incident cases of VaD by consensus. We searched for similar studies published up to October 2019 using PubMed and Web of Science. Observational studies reporting associations between anxiety and VaD risk, and adjusting at least for age, were selected. Odds ratios (ORs) from each study were combined using fixed-effects models. In the ZARADEMP study, the risk of VaD was 1.41 times higher among individuals with anxiety (95% CI: 0.75-2.68) compared with non-cases (p = 0.288). Pooling this result with results from two previous studies yielded an OR of 1.65 (95% CI: 1.07-2.53; p = 0.022). These findings indicate that anxiety is associated with an increased risk of VaD. Taking into account that anxiety is commonly observed in the elderly, treating and preventing it might reduce the prevalence and incidence of VaD. However, whether anxiety is a cause of a prodrome of VaD is still unknown, and future research is needed to clarify this
Activation and decay heat analysis of the European DEMO blanket concepts
Demonstrating tritium self-sufficiency is an important goal of the European tokamak demonstration fusion reactor. Currently four breeder blanket concepts are being considered: the Helium Cooled Pebble Bed (HCPB), Helium Cooled Lithium-Lead (HCLL), Dual Cooled Lithium-Lead (DCLL) and Water Cooled Lithium-Lead (WCLL). Differences in materials and construction of the four breeder blanket concepts lead to differing nuclear responses. As well as affecting tritium breeding this is also of particular importance in safety analyses, such as the modelling of loss of coolant accidents, as it affects the blanket\u27s decay heat and nuclide inventory.
This paper presents and discusses analysis performed for each of the 2014 designs of the blanket concepts to ascertain the decay heat and nuclide inventory for the entire reactor. It was found that the total decay heat at short decay times for the HCLL concept (17.5 MW at 1 s) was between 17% and 22% lower than the HCPB, WCLL and DCLL. At longer decay times (∼100 years) it was found that the DCLL and WCLL blankets had decay heats in the region of 2–3 orders of magnitude above the HCPB and HCLL blankets. The differences noted between the blanket concepts are discussed in terms of neutron spectrum and material compositio
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