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Relevant bibliographies by topics / Relativity (Physics)

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Academic literature on the topic 'Relativity (Physics)'

Author: Grafiati

Published: 4 June 2021

Last updated: 31 July 2024

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Journal articles on the topic "Relativity (Physics)"

1

Hammond, John L. "Relativity and relativism." American Journal of Physics 53, no. 9 (September 1985): 873–74. http://dx.doi.org/10.1119/1.14354.

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Galison, P. "PHYSICS: Astronomers' Relativity." Science 315, no. 5814 (February 16, 2007): 942–43. http://dx.doi.org/10.1126/science.1134451.

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Girelli, Florian, and Etera R. Livine. "Physics of deformed special relativity: relativity principle revisited." Brazilian Journal of Physics 35, no. 2b (June 2005): 432–38. http://dx.doi.org/10.1590/s0103-97332005000300011.

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Baylis, W. E. "Relativity in introductory physics." Canadian Journal of Physics 82, no. 11 (November 1, 2004): 853–73. http://dx.doi.org/10.1139/p04-058.

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A century after its formulation by Einstein, it is time to incorporate special relativity early in the physics curriculum. The approach advocated here employs a simple algebraic extension of vector formalism that generates Minkowski spacetime, displays covariant symmetries, and enables calculations of boosts and spatial rotations without matrices or tensors. The approach is part of a comprehensive geometric algebra with applications in many areas of physics, but only an intuitive subset is needed at the introductory level. The approach and some of its extensions are given here and illustrated with insights into the geometry of spacetime. PACS Nos.: 03.30.+p, 01.40.Gm, 03.50.De, 02.10.Hh

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ROSENBLUM, ARNOLD. "New Ideas in Relativity Physics." Annals of the New York Academy of Sciences 571, no. 1 Texas Symposi (December 1989): 276–87. http://dx.doi.org/10.1111/j.1749-6632.1989.tb50515.x.

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Mayants, Lazar. "Einstein's relativity and quantum physics." International Journal of Theoretical Physics 34, no. 8 (August 1995): 1575–85. http://dx.doi.org/10.1007/bf00676269.

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Griffin, David Ray. "Hartshorne, God, and Relativity Physics." Process Studies 21, no. 2 (1992): 85–112. http://dx.doi.org/10.5840/process199221230.

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Griffin, David Ray. "Hartshorne, God, and Relativity Physics." Process Studies 21, no. 2 (July 1, 1992): 85–112. http://dx.doi.org/10.2307/44798682.

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Cardall, Christian Y. "A Unified Perspective on Poincaré and Galilei Relativity: I. Special Relativity." Symmetry 16, no. 2 (February 10, 2024): 214. http://dx.doi.org/10.3390/sym16020214.

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A semantic adjustment to what physicists mean by the terms `special relativity’ and `general relativity’ is suggested, which prompts a conceptual shift to a more unified perspective on physics governed by the Poincaré group and physics governed by the Galilei group. After exploring the limits of a unified perspective available in the setting of 4-dimensional spacetime, a particular central extension of the Poincaré group—analogous to the Bargmann group that is a central extension of the Galilei group—is presented that deepens a unified perspective on Poincaré and Galilei physics in a 5-dimensional spacetime setting. The immediate focus of this paper is classical physics on affine 4-dimensional and 5-dimensional spacetimes (`special relativity’ as redefined here), including the electrodynamics that gave rise to Poincaré physics in the first place, but the results here may suggest the existence of a `Galilei general relativity’ more extensive than generally known, to be pursued in the sequel.

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Barbour, Julian, Brendan Z. Foster, and Niall $Oacute$ Murchadha. "Relativity without relativity." Classical and Quantum Gravity 19, no. 12 (May 31, 2002): 3217–48. http://dx.doi.org/10.1088/0264-9381/19/12/308.

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Dissertations / Theses on the topic "Relativity (Physics)"

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Starr, I. M. "Multidimensional relativity." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235269.

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Drake, S. P. "Axisymmetric spacetimes in relativity /." Title page, contents and introduction only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phd763.pdf.

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Farr, Will M. (Will Meierjurgen). "Numerical relativity from a gauge theory perspective." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62871.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2010.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 121-123).
I present a new method for numerical simulations of general relativistic systems that eliminates constraint violating modes without the need for constraint damping or the introduction of extra dynamical fields. The method is a type of variational integrator. It is based on a discretization of an action for gravity (the Plebański action) on an unstructured mesh that preserves the local Lorentz transformation and diffeomorphism symmetries of the continuous action. Applying Hamilton's principle of stationary action gives discrete field equations on the mesh. For each gauge degree of freedom there is a corresponding discrete constraint; the remaining discrete evolution equations exactly preserve these constraints under time-evolution. I validate the method using simulations of several analytically solvable spacetimes: a weak gravitational wave spacetime, the Schwarzschild spacetime, and the Kerr spacetime.
by Will M. Farr.
Ph.D.

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Sjödin, Robert. "Cosmic strings in general relativity." Thesis, University of Southampton, 2001. https://eprints.soton.ac.uk/50619/.

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In this thesis we examine the properties of Cosmic Strings in the theory of General Relativity. We begin by considering static Cosmic Strings in flat space-time. We derive the field equations for the Cosmic String and show that the solution depends upon a single scaling parameter a which is constructed from the physical constants. Using this result we construct 1-parameter families of solutions which depend on an auxiliary parameter e and which describe the thin-string limit of a Cosmic String. By interpreting these solutions as elements of the simplified Colombeau algebra we may interpret the relativistic energy density Too of the thin string as an element of the Colombeau algebra with delta-function mass-per-unit-length. Furthermore, for a critically coupled Cosmic String the energymomentum tensor in the thin-string limit may be given a distributional interpretation. We also solve the string equations numerically for various values of a. This is done by compactifying the space-time to include infinity as part of the numerical grid and then using a relaxation method to suppress exponentially growing un-physical solutions. In curved space-time we derive the equations for the scalar and vector fields which are now coupled to the geometric variables through Einstein's equations. We again examine the thin-string limit in the Colombeau algebra by considering a 1-parameter family of solutions. W'e derive an expression for the deficit angle in terms of the distributional energy-momentum tensor of the thin string. We use this result to investigate the gravitational lensing properties of the string and relate this to the deficit angle. In the special case of a cone we find the scattering angle is equal to the deficit angle. We also solve the coupled equations numerically using techniques similar to those used in flat space-time. The second part of the thesis involves the dynamics of Cosmic Strings. Einstein's equations then lead to wave equations for both the matter and metric variables. However, the space-time is not asymptotically flat and this leads to problems in applying the appropriate boundary conditions. By using a Geroch transformation it is possible to reformulate the equations in terms of geometrical variables defined on an asymptotically flat (2+l)-dimensional space-time. Three exact vacuum solutions describing gravitational radiation due to Weber-Wheeler, Xanthopoulos and Piran et al. are used to excite the string which is found to oscillate with frequencies which are proportional to the masses of the scalar and vector fields of the string. This is in agreement with the exact results obtained using the linearised equations of the thin dynamic string. The behaviour of the dynamic string is studied by solving the equations numerically using an implicit fully characteristic scheme. The use of the Geroch transformation allows us to compactify the space-time and include null infinity as part of the numerical grid. This enables us to use the correct boundary conditions at infinity and hence suppress un-physical divergent solutions. The code is tested by comparing the results with exact solutions, by checking that it agrees with the static code and by undertaking a time dependent convergence test. The code is found to be accurate, stable and exhibit clear second order convergence.

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O'Donnell, N. "Electromagnetic radiation reaction in general relativity." Thesis, Bucks New University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384632.

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Kotze, Jacques. "An introduction to general relativity and entropy bounds." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/17375.

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Thesis (MSc)--University of Stellenbosch, 2006.
ENGLISH ABSTRACT: Entropy bounds arise from Black hole thermodynamics and are a significant departure from the conventional understanding of the information in a given region. This shift in paradigm is a consequence of the the fact that there is an unexpected relationship between the area and the entropy of a given region of spacetime. Entropy bounds are simplified formulations which are ultimately attempting to be developed into the complete and broad conjecture of the Holographic Principle. This hasn’t been achieved successfully as yet. In this thesis the aim is to introduce how the notion of an entropy bound was first suggested and it’s subsequent development into more robust formulations. The shortcomings of these conjectures are highlighted along with their strengths. A foundational introduction of the mathematical requirements for General Relativity is addressed along with an overview of Einstein’s theory of gravity. This is illustrated by showing the curvature of relative geodesics as being a consequence of gravity. This is contrasted with Newtonian theory where gravity is also shown to manifests as the curvature of relative geodesics. The working background is concluded with a discussion of Einstein’s field equations along with simple and common solutions often used and required.
AFRIKAANSE OPSOMMING: Swartgat Termodinamika impliseer grense op die entropie, en dus inligting, in ’n gegewe ruimtetyd volume, wat ’n drastiese afwyking van die tradisionele denkwyse oor inligting impliseer. Hierdie paradigma skuif het sy oorsprong in ’n onverwagte verband tussen die oppervlakte van, en entropie bevat, in ’n gegewe ruimte tyd volume. Entropie grense is eenvoudige formulerings van hierdie verwantskap wat uiteindelik beslag moet kry in die vollediger en wyer holografiese beginsel. Hierdie doelwit is nog nie bereik nie. Die doel van hierdie tesis is om die oorsprong en verdere formalisering van entropie grense te verduidelik. Beide die sterk en swak punte van die formulerings word bespreek. Algemene relatiwiteits teorie as ’n teorie van gravitasie, sowel as die wiskundige onderbou daarvan, word oorsigtelik bespreek. Die geometries onderbou van gravitasie word geillustreer aan die hand van die buiging van relatiewe geodete. Dit word met Newton se gravitasie teorie vergelyk wat ook in die buiging van relatiewe geodete gemanifesteer word. Hierdie oorsigtelike agtergrond word afgesluit met ’n oorsig van Einstein se vergelykings, asook eenvoudige en algemene oplossings wat dikwels nodig is en gebruik word.

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Sixaba, Vuyile. "Geometry of deformed special relativity." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/59478.

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We undertake a study of the classical regime in which Planck's constant and Newton's gravitational constant are negligible, but not their ratio, the Planck mass, in hopes that this could possibly lead to testable quantum gravity (QG) effects in a classical regime. In this quest for QG phenomenology we consider modifications of the standard dispersion relation of a free particle known as deformed special relativity (DSR). We try to geometrize DSR to find the geometric origin of the spacetime and momentum space. In particular, we adopt the framework of Hamilton geometry which is set up on phase space, as the cotangent bundle of configuration space in order to derive a purely phase space formulation of DSR. This is necessary when one wants to understand potential links of DSR with modifications of quantum mechanics such as Generalised Uncertainty Principles. It is subsequently observed that space-time and momentum space emerge naturally as curved and intertwined spaces. In conclusion we mention examples and applications of this framework as well as potential future developments.

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Roy, Ian M. "Projective and Ricci collineations in general relativity." Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU099861.

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The thesis considers various problems in general relativity concerning projective and Ricci collineations. A result due to Yano in the maximum dimension of the projective algebra on a non-flat space-time is improved using a pointwise classification scheme. The converse of a result, relating Weyl projective vector fields and curvature collineations under certain well defined circumstances, is given. A result is presented showing that, under specified conditions a space-time admitting a proper special projective vector field admits a proper special conformal vector field and vice versa. The work done on Ricci/Matter collineations gives a general mathematical treatment of these vector fields where particular emphasis is placed on decomposable space-times. Problems of differentiability, extendibility, etc are described.

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Walter, Scott. "Henri Poincaré, theoretical Physics, and Relativity Theory in Paris." Wissenschaftlicher Verlag Harri Deutsch, 2011. https://slub.qucosa.de/id/qucosa%3A16256.

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Sylvester, Alex J. "Testing General Relativity with Spherical Resonant Mass Detectors." Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002423.

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Gravitational waves in f(R) gravity excite monopole and m = 0±2 quadrupole resonance modes of a spherical detector. This document reviews the basic ideas of general relativity and gravitational waves, and then applies those concepts to an f( R) gravitational wave. The acoustic response of a GW incident with a spherical detector is reviewed in detail, and the absorption cross section for an f(R) GW impinging on the spherical detector is calculated. Minimum detectable scalar wave amplitudes are explored for the Mario Schenberg detector. The mass of the scalar mode affects its detectability.

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Books on the topic "Relativity (Physics)"

1

Einstein, Albert. The meaning of relativity. 5th ed. Princeton: Princeton University Press, 1988.

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Hoffmann, Banesh. Relativity and its roots. Mineola, N.Y: Dover Publications, 1999.

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Mook, Delo E. Inside relativity. Princeton, N.J: Princeton University Press, 1987.

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Russell, Bertrand. ABC of relativity. 5th ed. London: Routledge, 1997.

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Russell, Bertrand. ABC of relativity. 4th ed. London: Unwin Paperbacks, 1985.

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Stannard, Russell. Relativity. New York, NY: Sterling Pub., 2010.

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Stannard, Russell. Relativity. New York: Sterling Pub., 2011.

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Brewster, Hilary D. Relativity. Jaipur, India: Oxford Book Co., 2009.

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Mould, Richard A. Basic relativity. 3rd ed. New York: Springer-Verlag, 1996.

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Mould, Richard A. Basic relativity. New York: Springer-Verlag, 2002.

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Book chapters on the topic "Relativity (Physics)"

1

Wellner, Marcel. "Relativity." In Elements of Physics, 577–94. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3860-8_25.

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Tsamparlis, Michael. "Newtonian Physics." In Special Relativity, 67–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03837-2_3.

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Tsamparlis, Michael. "Newtonian Physics." In Special Relativity, 71–90. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-27347-7_3.

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Finkelstein, David Ritz. "Non-Objective Physics." In Quantum Relativity, 153–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-60936-7_5.

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Keeton, Charles. "Relativity." In Undergraduate Lecture Notes in Physics, 177–219. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4614-9236-8_10.

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Barrett, Ross, Pier Paolo Delsanto, and Angelo Tartaglia. "Relativity." In Undergraduate Lecture Notes in Physics, 77–99. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-31691-8_7.

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Liebscher, Dierck-Ekkehard. "Relativity." In Springer Tracts in Modern Physics, 25–51. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/978-3-540-31502-5_2.

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Russell, Bertrand. "Pre-Relativity Physics." In The Analysis of Matter, 13–22. London: Routledge, 2022. http://dx.doi.org/10.4324/9781003308898-3.

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Hacyan, Shahen. "Modern Physics: Relativity." In The Frontiers Collection, 39–51. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-21254-3_4.

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Cini, Michele. "Special Relativity." In UNITEXT for Physics, 97–122. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-71330-4_6.

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Conference papers on the topic "Relativity (Physics)"

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Allen, Roland E. "Relativity, Particle Physics and Cosmology." In Richard Arnowitt Fest. WORLD SCIENTIFIC, 1999. http://dx.doi.org/10.1142/9789814527620.

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Bassan, M., V. Ferrari, M. Francaviglia, F. Fucito, and I. Modena. "General Relativity and Gravitational Physics." In 12th Italian Conference. WORLD SCIENTIFIC, 1996. http://dx.doi.org/10.1142/9789814529693.

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Carfora, M., M. Cavaglià, M. Francaviglia, P. Fré, G. Pizzella, C. Reina, and A. Treves. "General Relativity and Gravitational Physics." In Proceedings of the 11th Italian Conference. WORLD SCIENTIFIC, 1996. http://dx.doi.org/10.1142/9789814530613.

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Cerdonio, M., R. D'Auria, M. Francaviglia, and G. Magnano. "General Relativity & Gravitational Physics." In 10th Italian Conference. WORLD SCIENTIFIC, 1994. http://dx.doi.org/10.1142/9789814534475.

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Cerdonio, M., R. Cianci, M. Francaviglia, and M. Toller. "GENERAL RELATIVITY AND GRAVITATIONAL PHYSICS." In 8th Italian Conference on General Relativity and Gravitational Physics. WORLD SCIENTIFIC, 1989. http://dx.doi.org/10.1142/9789814541404.

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Cianci, R., R. de Ritis, M. Francaviglia, G. Marmo, C. Rubano, and P. Scudellaro. "GENERAL RELATIVITY AND GRAVITATIONAL PHYSICS." In 9th Italian Conference. WORLD SCIENTIFIC, 1991. http://dx.doi.org/10.1142/9789814538473.

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Abdullin, Albert. "ON SPECIAL RELATIVITY TEACHING." In Modern problems of physics education. Baskir State University, 2021. http://dx.doi.org/10.33184/mppe-2021-11-10.8.

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Jafari, Nosratollah. "Doubly Special Relativity: A New Relativity or Not." In A CENTURY OF RELATIVITY PHYSICS: ERE 2005; XXVIII Spanish Relativity Meeting. AIP, 2006. http://dx.doi.org/10.1063/1.2218214.

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Moreno Gonzalez, Claudia. "Gravitational Perturbations in General Relativity." In ADVANCED SUMMER SCHOOL IN PHYSICS 2006: Frontiers in Contemporary Physics: EAV06. AIP, 2007. http://dx.doi.org/10.1063/1.2563175.

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Aldrovandi, R., J. P. Beltrán Almeida, C. S. O. Mayor, J. G. Pereira, Guillaume Adenier, Andrei Yu Khrennikov, Pekka Lahti, Vladimir I. Man'ko, and Theo M. Nieuwenhuizen. "de Sitter Relativity and Quantum Physics." In Quantum Theory. AIP, 2007. http://dx.doi.org/10.1063/1.2827302.

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Reports on the topic "Relativity (Physics)"

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Saptsin, V., Володимир Миколайович Соловйов, and I. Stratychuk. Quantum econophysics – problems and new conceptions. КНУТД, 2012. http://dx.doi.org/10.31812/0564/1185.

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This article is dedicated to the econophysical analysis of conceptual fundamentals and mathematical apparatus of classical physics, relativity theory, non-relativistic and relativistic quantum mechanics. The historical and methodological aspects as well as the modern state of the problem of the socio-economic modeling are considered.

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Saptsin, Vladimir, and Володимир Миколайович Соловйов. Relativistic quantum econophysics – new paradigms in complex systems modelling. [б.в.], July 2009. http://dx.doi.org/10.31812/0564/1134.

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This work deals with the new, relativistic direction in quantum econophysics, within the bounds of which a change of the classical paradigms in mathematical modelling of socio-economic system is oﬀered. Classical physics proceeds from the hypothesis that immediate values of all the physical quantities, characterizing system’s state, exist and can be accurately measured in principle. Non-relativistic quantum mechanics does not reject the existence of the immediate values of the classical physical quantities, nevertheless not each of them can be simultaneously measured (the uncertainty principle). Relativistic quantum mechanics rejects the existence of the immediate values of any physical quantity in principle, and consequently the notion of the system state, including the notion of the wave function, which becomes rigorously nondeﬁnable. The task of this work consists in econophysical analysis of the conceptual fundamentals and mathematical apparatus of the classical physics, relativity theory, non-relativistic and relativistic quantum mechanics, subject to the historical, psychological and philosophical aspects and modern state of the socio-economic modeling problem. We have shown that actually and, virtually, a long time ago, new paradigms of modeling were accepted in the quantum theory, within the bounds of which the notion of the physical quantity operator becomes the primary fundamental conception(operator is a mathematical image of the procedure, the action), description of the system dynamics becomes discrete and approximate in its essence, prediction of the future, even in the rough, is actually impossible when setting aside the aftereﬀect i.e. the memory. In consideration of the analysis conducted in the work we suggest new paradigms of the economical-mathematical modeling.

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Clausen, Jay, Christopher Felt, Michael Musty, Vuong Truong, Susan Frankenstein, Anna Wagner, Rosa Affleck, Steven Peckham, and Christopher Williams. Modernizing environmental signature physics for target detection—Phase 3. Engineer Research and Development Center (U.S.), March 2022. http://dx.doi.org/10.21079/11681/43442.

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The present effort (Phase 3) builds on our previously published prior efforts (Phases 1 and 2), which examined methods of determining the probability of detection and false alarm rates using thermal infrared for buried object detection. Environmental phenomenological effects are often represented in weather forecasts in a relatively coarse, hourly resolution, which introduces concerns such as exclusion or misrepresentation of ephemera or lags in timing when using this data as an input for the Army’s Tactical Assault Kit software system. Additionally, the direct application of observed temperature data with weather model data may not be the best approach because metadata associated with the observations are not included. As a result, there is a need to explore mathematical methods such as Bayesian statistics to incorporate observations into models. To better address this concern, the initial analysis in Phase 2 data is expanded in this report to include (1) multivariate analyses for detecting objects in soil, (2) a moving box analysis of object visibility with alternative methods for converting FLIR radiance values to thermal temperature values, (3) a calibrated thermal model of soil temperature using thermal IR imagery, and (4) a simple classifier method for automating buried object detection.

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Sapienza, Francis, Michael Parker, Mark Bodie, and Sally Shoop. Vehicle modeling in Unreal Engine 4. Engineer Research and Development Center (U.S.), November 2023. http://dx.doi.org/10.21079/11681/47923.

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Vehicle modeling software has presented considerable challenges in properly representing vehicle mobility in extreme conditions. We have recently been developing new vehicle models and scenes in Unreal Engine. Unreal Engine is best known as a video game creation platform focused on graphics and has relatively few options for real world accurate physics modeling. UE4 allows for lots of customization internally or via supplemental C++ code, so this can be mitigated by the addition of various functions to account for different situations a vehicle might be in. We have successfully implemented the following: accurately functioning wheeled vehicles, tracked vehicles, and created simulated and real world environments, downloaded through Geowatch heightmaps. Each environment can have various terrain conditions including soil, rock, snow, and sand applied across its surface. Modeling snow in these environments is of particular interest and recent motion resistance and sinkage models have been integrated into the software to affect graphics and vehicle performance. This new model for vehicle mobility offers an opportunity to improve the physics and graphics of differing terrains especially for winter conditions. The new model also allows for features to be updated and added with ease in the future.

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Waganet, R. J., John Duxbury, Uri Mingelgrin, John Hutson, and Zev Gerstl. Consequences of Nonequilibrium Pesticide Fate Processes on Probability of Leaching from Agricultural Lands. United States Department of Agriculture, January 1994. http://dx.doi.org/10.32747/1994.7568769.bard.

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Pesticide leaching in heterogeneous field soils is relatively unstudied and is the focus of this project. A wide variety of heterogeneous soils exist, characterized by processes that result from the presence of structural cracks, worm holes, and other preferred pathways within which the majority of transport can occur (called physical non-equilibrium processes), along with the presence of sorption processes that are both equilibrium and kinetic (chemical non-equilibrium processes). Previous studies of pesticide leaching have focused primarily on relatively homogeneous soils, which are less widely distributed in nature, but more studied due to the relative ease with which quantitative theory can be applied to interpret experimental results. The objectives of the proposed project were: first, to gain greater insight into the basic physical and chemical processes that characterize non-equilibrium systems, second, to improve our ability to predict pesticide leaching in heterogeneous field soils, and third, to estimate the consequences of non-equilibrium processes at the field scale by conducting an analysis of the probability of pesticide leaching when non-equilibrium processes prevail. The laboratory, theoretical and modelling aspects of the project were successful; the field aspects less so. We gained greater insight into basic processes in heterogeneous field soils, and we improved and tested tools (simulation models) and the methodology of using such tools for assessing the probability of pesticide leaching as a contribution to broader risk analysis efforts.

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Song, Frank, and Narasi Sridhar. DTRS56-04-T-0002 Determining Reassessment Intervals Through Corrosion. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2006. http://dx.doi.org/10.55274/r0011958.

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The objectives of this program are to develop methods based on sound fundamental principles to estimate: (1) external corrosion rates, especially in CP shielded areas, and (2) internal corrosion rates by considering pipeline-relevant factors for gas and liquid lines. Mathematical models will be developed to achieve the above goal. The models will be compared with field and laboratory data for validity and the models will be simplified to a format that is applicable to pipeline operators to estimate pipeline external or/and internal corrosion rate. It is recognized that the development of fundamental, physics-based models to predict corrosion rates for each of these areas is a daunting task. Therefore, this project aims to develop models that can be used to predict the pipeline corrosion rate in some scenarios that are relatively conservative and are expected to occur more commonly in the field. The goals were (1) external corrosion rate calculation, (2) internal corrosion rate calculation, (3) validation of the external corrosion rate calculation, (4) field validation of the internal corrosion rate calculation, and (5) reporting and recommendations.

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Glasscott, Matthew. Classifying and benchmarking high-entropy alloys and associated materials for electrocatalysis : a brief review of best practices. Engineer Research and Development Center (U.S.), January 2024. http://dx.doi.org/10.21079/11681/48082.

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In light of the immense compositional diversity of high-entropy materials (HEMs) recently reported (e.g., high-entropy chalcogenides, perovskites, ceramics, etc.) and the relatively amorphous definition of High-Entropy, it is imperative that consistent material classification and benchmarking practices be employed to facilitate comparison between reported figures of merit. In this opinion, an updated form of the numerical high-entropy definition is reviewed, which renders a universal entropy metric applicable to high-entropy alloys and emerging HEMs alike. Analytical methods to verify the existence of a solid-solution microstructure, elucidate atomic valence states, and probe atomic disorder are discussed with literature examples to facilitate the physical classification of HEMs. Electrocatalytic benchmarking is discussed in the context of water-splitting reactions and best practices are reviewed for determining the electrocatalytically active surface area, reaction overpotential, and electrocatalyst stability.

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van der Mensbrugghe, Dominique. Using Python for Parallelization. GTAP Working Paper, April 2023. http://dx.doi.org/10.21642/gtap.wp93.

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This short note describes one way of taking advantage of the multiple cores on most desktop computers. It describes running one of the processes in the GTAP build procedure called ’FIT’. The input to ’FIT’ is a balanced input-output table (IOT), which is adjusted to a number of exogenous elements including aggregate domestic absorption and import and export vectors. It is run for each of the countries/regions in the build, but there is no interaction across countries/regions and thus can be run in parallel. The procedure uses a Python script to run the ’FIT’ procedure, either sequentially or in parallel. Most of the code is generic and thus it can be easily adapted to other programs that can take advantage of parallelism, for example Monte Carlo simulations. For the tested ’FIT’ procedure, it reduces the runtime from 75 minutes to 14 minutes on a relatively new desktop with a 12th Generation Intel Core I-9 CPU with 16 physical cores.

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Smit, Timo, Sofia Sacks Ferrari, and Jaïr van der Lijn. Trends in Multilateral Peace Operations, 2019. Stockholm International Peace Research Institute, May 2020. http://dx.doi.org/10.55163/ixjs4170.

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Despite evidence of their positive impacts, United Nations peacekeeping operations continue to face budget cuts, cynicism in the political arena and concern over personnel physical safety. This context underpins the global and regional trends in multilateral peace operations in 2019. This SIPRI Fact Sheet gives a snapshot of multilateral peace operations in 2019, with statistics on personnel, country contributions and fatalities for operations conducted by the UN, regional organizations or alliances, and ad hoc coalitions of states. Global and regional trends in 2019 follow developments from recent years, including the downward trends associated with the reductions and closures of many UN peace operations since 2015. Sub-Saharan Africa continues to host the majority of operations and personnel, although these numbers have decreased, while the Middle East and North Africa is drawing attention for increasing numbers of operations and personnel. Hostile death rates for 2019 are largely attributed to the UN Multidimensional Integrated Stabilization Mission in Mali, the deadliest operation since its establishment in 2013, with all other operations demonstrating relatively low numbers of fatalities.

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Iffat, Idris. Use of Online Space in Pakistan Targeting Women, Religious Minorities, Activists and Voices of Dissent. Institute of Development Studies, March 2022. http://dx.doi.org/10.19088/k4d.2022.071.

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There is ample evidence that online hate speech in Pakistan is directed against women, religious minorities, journalists, voices of dissent and activists. The targeting of many of these groups is an expansion online of the traditional hostility and abuse they face offline. However, the internet has made such abuse easier and online hate speech is growing as internet use rises in the country. Those responsible vary somewhat: women and religious minorities are typically targeted by religio-political parties and their followers, while journalists and activists are often targeted by government/the military. In all cases, online hate speech can have a serious offline impact, including physical violence, and restrictions on people’s freedom/ability to work/post online. This review, looking at online hate speech in Pakistan in relation to particular groups, draws largely on reports by think-tanks/NGOs as well as media articles and blogs. Relatively little academic literature was found on the subject, but grey literature was quite extensive, especially on certain religious minorities (Ahmadis) and women.

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