A Review of Computational Approaches to the Microstructure-Informed Mechanical Modelling of Metals Produced by Powder Bed Fusion Additive Manufacturing

In the rapidly evolving field of additive manufacturing (AM), the predictability of part properties is still challenging due to the inherent multiphysics complexity of the technology. This results in time-consuming and costly experimental guess-and-check approaches for manufacturing each individual design. Through synthesising advancements in the field, this review argues that numerical modelling is instrumental in mitigating these challenges by working in tandem with experimental studies. Unique hierarchical microstructures induced by extreme AM process conditions– including melt pool patterns, grains, cellular–dendritic substructures, and precipitates—affect the final part properties. Therefore, the development of microstructure-informed mechanical models becomes vital. Our review of numerical studies explores various modelling approaches that consider the microstructural features explicitly and offers insights into multiscale stress–strain analysis across diverse materials fabricated by powder bed fusion AM. The literature indicates a growing consensus on the key role of multiscale integrated process–structure–property–performance (PSPP) modelling in capturing the complexity of AM-produced materials. Current models, though increasingly sophisticated, still tend to relate only two elements of the PSPP chain while often focusing on a single scale. This emphasises the need for integrated PSPP approaches validated by a solid experimental base. The PSPP paradigm for AM, while promising as a concept, is still in its infantry, confronting multifaceted challenges that require in-depth, multidisciplinary expertise. These challenges range from accounting for multiphysics phenomena (e.g., advanced laser–material interaction) and their interplay (thermo-mechanical and microstructural evolution for simulating Type II residual stresses), accurately defined assumptions (e.g., flat molten surface during AM or purely epitaxial solidification), and correctly estimated boundary conditions for each element of the PSPP chain up to the need to balance the model’s complexity and detalisation in terms of both multiphysics and discretisation with efficient multitrack and multilayer simulations. Efforts in bridging these gaps would not only improve predictability but also expedite the development and certification of new AM materials

Mixed-symmetry massive fields in AdS(5)

Free mixed-symmetry arbitrary spin massive bosonic and fermionic fields propagating in AdS(5) are investigated. Using the light-cone formulation of relativistic dynamics we study bosonic and fermionic fields on an equal footing. Light-cone gauge actions for such fields are constructed. Various limits of the actions are discussed.Comment: v3: 24 pages, LaTeX-2e; typos corrected, footnote 7 and 2 references added, published in Class. Quantum Gra

An Encyclopaedic dictionary of the history of the merchant class and trade in Siberia: recovered names and discovered destinies

The article was submitted on 28.03.2015.The article is a description of a research project that has been developed for several years now and is devoted to the study of Russian entrepreneurship history. One of the stages of the project was the creation of An Encyclopaedic Dictionary of the History of the Merchant Class and Trade in Siberia (Novosibirsk, Izdatel'stvo «GEO», 2012–2013). This is an unparalleled publication, the first dictionary of this kind in Russian historiography and it is worthy of attention because of the amount of information included and its structure (it contains videos, an academic bibliography, and the choice of authors is remarkable). The project is discussed by Vasiliy Pavlovich Zinoviev, professor of history (Tomsk State University), an eminent specialist in the economic history of Siberia; Evgeniya Vladislavovna Komleva, leading research fellow of the Department of the 2nd Half of the16th – Early 20th Century History of the Institute of History (Russian Academy of Sciences, Siberian Branch), executive editor of the Dictionary; Olga Dmitrievna Zhuravel’, dean of the faculty of Journalism, Novosibirsk State University. The article describes the problems that underlie the realization of this unique large-scale project, the informational potential of the Dictionary that makes it possible to substantiate not only the economic but also cultural paradigm, as well as entrepreneurship as a mode of living of Siberian merchants.Обсуждение научного проекта, длившегося несколько лет и продолжающегося сейчас, по изучению истории российского предпринимательства. Одним из этапов стало создание коллективом авторов двухтомного «Энциклопедического словаря по истории купечества и коммерции Сибири» (Новосибирск: Академическое издательство «Гео», 2012–2013). Уникальное издание, фактически первое такого рода в российской историографии, привлекает внимание объемом информации и продуманной системой оформления (видеоряд, научная библиография, подбор авторов). В обсуждении данного проекта принимают участие Василий Павлович Зиновьев, доктор исторических наук, профессор Томского государственного университета, известный специалист по экономической истории Сибири; Евгения Владиславовна Комлева, старший научный сотрудник сектора истории второй половины XVI – начала XX в. Института истории СО РАН, ответственный секретарь издания; Ольга Дмитриевна Журавель, доктор филологических наук, декан факультета журналистики Новосибирского государственного университета. Речь пойдет о сложности реализации этого уникального широкомасштабного проекта, об информационных возможностях словаря для раскрытия не только экономической, но и культурной парадигмы, о предпринимательстве как образе жизни сибирских купцов

On the prevention of gastrointestinal bleeding in burned patients treated with omeprazole

Background: The incidence of gastrointestinal bleeding in patients with severe burns can reach up to 10%.Objective: Evaluation of the risk factors for gastrointestinal bleeding and of the effectiveness of stress ulcer prophylaxis in patients with severe burns receiving proton pump inhibitors.Material and methods: The study included the results of treatment of 270 patients with burns more than 10% of total body surface area (TBSA), in whom 13 potential risk factors for gastrointestinal bleeding were studied. All patients received omeprazole therapy with 40 mg № 1 intravenous or 20 mg № 2 orally. The data obtained were processed in Microsoft Office Excel 2007 and IBM SPSS 20.0.Results: Significant risk factors for gastrointestinal bleeding were hypotension requiring treatment with vasopressors (dopamine ≥ 10 μg/kg/min or norepinephrine ≥ 0.5 μg/kg/min) for 2 or more days (χ2 = 5.126; p = 0.024) and full thickness burns with more than 50% of total body surface area (χ2 = 7.031; p = 0.008). The incidence of gastrointestinal bleeding was 4%. These bleedings were hemodynamically insignificant; in all cases, acute ulcers were the cause for them. There were no recurrences of bleeding and no repeated endoscopy or surgical treatment was required. The developed bleeding did not have a significant effect on mortality.Conclusion: Using proton pump inhibitors minimizes the frequency and intensity of gastrointestinal bleeding and also prevents lifethreatening complications during their development. More complex prevention of stress ulceration is necessary for patients with full thickness burns more than 50% of TBSA which develop hypotension requiring long‑term vasopressor therapy

BRST approach to Lagrangian formulation of bosonic totally antisymmeric tensor fields in curved space

We apply the BRST approach, previously developed for higher spin field theories, to gauge invariant Lagrangian construction for antisymmetric massive and massless bosonic fields in arbitrary d-dimensional curved space. The obtained theories are reducible gauge models both in massless and massive cases and the order of reducibility grows with the value of the rank of the antisymmetric field. In both the cases the Lagrangians contain the sets of auxiliary fields and possess more rich gauge symmetry in comparison with standard Lagrangian formulation for the antisymmetric fields. This serves additional demonstration of universality of the BRST approach for Lagrangian constructions in various field models.Comment: 12 page

Cooperative Recombination of a Quantized High-Density Electron-Hole Plasma

We investigate photoluminescence from a high-density electron-hole plasma in semiconductor quantum wells created via intense femtosecond excitation in a strong perpendicular magnetic field, a fully-quantized and tunable system. At a critical magnetic field strength and excitation fluence, we observe a clear transition in the band-edge photoluminescence from omnidirectional output to a randomly directed but highly collimated beam. In addition, changes in the linewidth, carrier density, and magnetic field scaling of the PL spectral features correlate precisely with the onset of random directionality, indicative of cooperative recombination from a high density population of free carriers in a semiconductor environment

Peculiarities of phonon spectra and lattice heat capacity in Ir and Rh

A simple pseudopotential model is proposed, which allows the phonon spectra and temperature dependence of the lattice heat capacity of Ir and Rh be described with a high enough accuracy. A careful comparison of the calculated and experimental values of the lattice heat capacity is carried out, with the procedure of the identification of the phonon contribution to the heat capacity and determination of the characteristics (momenta) of the phonon density of states from the experimental values of the total heat capacity of metal at a constant pressure being described in detail. The results of the theoretical calculations explain, in particular, such peculiar feature of Ir and Rh, unusual for cubic metals, as a sharp (more than by a factor of 1.5) decrease in the effective Debye temperature with increasing termperature. The temperature dependence of the mean square amplitude of atomic displacements in Ir and Rh has been calculated. Basing on the band calculations the manifestation of the Kohn singularities in the phonon spectra of Ir are discussed.Comment: 15 pages, LaTeX2e, 12 figures in postscrip