We perform a rare-event study on a simulated power system in which grid-scale batteries provide both regulation and emergency frequency control ancillary services. Using a model of random power disturbances at each bus, we employ the skipping sampler, a Markov Chain Monte Carlo algorithm for rare-event sampling, to build conditional distributions of the power disturbances leading to two kinds of instability: frequency excursions outside the normal operating band, and load shedding. Potential saturation in the benefits, and competition between the two services, are explored as the battery maximum power output increases. This article is part of the theme issue 'The mathematics of energy systems'.
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http://dx.doi.org/10.1098/rsta.2019.0433 | DOI Listing |
Nano Lett
January 2025
Department of Mechanical Engineering & Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
The development of accurate methods for determining how alloy surfaces spontaneously restructure under reactive and corrosive environments is a key, long-standing, grand challenge in materials science. Using machine learning-accelerated density functional theory and rare-event methods, in conjunction with environmental transmission electron microscopy (ETEM), we examine the interplay between surface reconstructions and preferential segregation tendencies of CuNi(100) surfaces under oxidation conditions. Our modeling approach predicts that oxygen-induced Ni segregation in CuNi alloys favors Cu(100)-O c(2 × 2) reconstruction and destabilizes the Cu(100)-O (2√2 × √2)45° missing row reconstruction (MRR).
View Article and Find Full Text PDFJ Consult Clin Psychol
January 2025
Department of Clinical Psychology, Faculty of Social and Behavioural Sciences, Utrecht University.
Objective: Sudden gains describe large and stable reductions in symptoms between two consecutive treatment sessions and have not yet been investigated in prolonged grief disorder (PGD), a new disorder in the 11th edition of the and text revision of the fifth edition of the characterized by separation distress and accompanying symptoms beyond 6 months of bereavement. The study aimed to examine the occurrence of sudden gains and their relation to treatment outcome and content during cognitive behavioral therapy (CBT) and supportive counseling for children and adolescents with PGD symptoms.
Method: We used data from 118 patients (50% female; age: = 12.
J Eval Clin Pract
February 2025
Department of Epidemiology and Biostatistics, University of Arizona, Tucson, Arizona, USA.
Rationale: Zero-event counts are common in clinical studies, particularly when assessing rare adverse events. These occurrences can result from low event rates, short follow-up periods, and small sample sizes. When both intervention and control groups report zero events in a clinical trial, the study is referred to as a double-zero-event study, which presents methodological challenges for evidence synthesis.
View Article and Find Full Text PDFJ Clin Med
December 2024
Department of Biomedical and Clinical Sciences, University of Milan, 20122 Milan, Italy.
: ST-segment elevation myocardial infarction (STEMI) remains a leading cause of mortality worldwide, primarily caused by acute thrombosis over atherosclerotic plaques. Simultaneous acute thrombosis in two coronary arteries is an exceptionally rare event. This report highlights a unique case of STEMI associated with cardiogenic shock due to dual coronary artery thrombosis and provides insights from a literature review on this rare condition.
View Article and Find Full Text PDFCancer Diagn Progn
January 2025
AntiCancer Inc., San Diego, CA, U.S.A.
Background/aim: Chronic lymphocytic leukemia (CLL) is currently incurable. CLL is characterized by disordered DNA methylation. The aim of the present study was to target methylation with methionine restriction in a patient with progressive CLL.
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