3,188 research outputs found
'Seeing Shit': Assessing the Visibility of Dung Tempering in Ancient Pottery Using an Experimental Approach
Widespread ethnographic evidence exists for the addition of animal dung to clay during the process of ceramic production. However, conclusive evidence of dung tempering in archaeological ceramics is relatively rare. The aim of this study is to ascertain whether, and under which conditions, dung tempering of pottery is identifiable. To answer these questions, we assessed whether a combination of micro-particle analysis in loose sediment and thin-section petrography can reveal the addition of dung to the clay paste by focusing on faecal spherulites, ash pseudomorphs, phytoliths and coprophilous fungal spores. We analysed several series of experimentally produced ceramic briquettes tempered with different types of dung and dung ash, which were fired at a range of increasing temperatures. Our study shows that the identification of dung tempering represents a challenge, and it depends on a number of different factors, among others the original presence of dung markers in the dung used, the manufacturing process, the firing temperatures and the firing atmosphere. Overall, through a multidisciplinary approach, our work clarifies a variety of issues connected to the identification of dung in ancient pottery, highlighting the role of faecal spherulites as the most promising proxy
Black Holes and Random Matrices
We argue that the late time behavior of horizon fluctuations in large anti-de
Sitter (AdS) black holes is governed by the random matrix dynamics
characteristic of quantum chaotic systems. Our main tool is the
Sachdev-Ye-Kitaev (SYK) model, which we use as a simple model of a black hole.
We use an analytically continued partition function as well
as correlation functions as diagnostics. Using numerical techniques we
establish random matrix behavior at late times. We determine the early time
behavior exactly in a double scaling limit, giving us a plausible estimate for
the crossover time to random matrix behavior. We use these ideas to formulate a
conjecture about general large AdS black holes, like those dual to 4D
super-Yang-Mills theory, giving a provisional estimate of the crossover time.
We make some preliminary comments about challenges to understanding the late
time dynamics from a bulk point of view.Comment: 73 pages, 15 figures, minor errors correcte
Harnessing the benefits of sanctuary scholarship: opportunities for community enhancement, widening participation and internationalisation at home
The paper focuses on the importance of Internationalisation at Home, access and support mechanisms which are provided and co-created by students and university departments to encourage sanctuary scholarship. The paper gives particular attention to activities that encourage meaningful interaction with local communities and widen international participation of marginalised groups, such as students from the global south and asylum seeker communities. The paper presents two case studies. The first case study focuses on a student-led project developed by the students and staff of Canterbury Christ Church University. The second case study projects students’ voices from the global south and refugee communities at The University of Kent and University College London (UCL). The experiences of these students highlight the importance of welcoming and supporting students from marginalised backgrounds. They also demonstrate the need for both curriculum-based and co-curricular activity and student services which provided tailored support and encouragement
Renormalization group approach to vibrational energy transfer in protein
Renormalization group method is applied to the study of vibrational energy
transfer in protein molecule. An effective Lagrangian and associated equations
of motion to describe the resonant energy transfer are analyzed in terms of the
first-order perturbative renormalization group theory that has been developed
as a unified tool for global asymptotic analysis. After the elimination of
singular terms associated with the Fermi resonance, amplitude equations to
describe the slow dynamics of vibrational energy transfer are derived, which
recover the result obtained by a technique developed in nonlinear optics [S.J.
Lade, Y.S. Kivshar, Phys. Lett. A 372 (2008) 1077].Comment: 11 page
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