641 research outputs found
A Comparative Study of Conditional Moment Closure Modelling for Ignition of iso-octane and n-heptane in Thermally Stratified Mixtures
No full textThis paper presents a comparative study of the premixed conditional moment closure (CMC) model for modelling ignition of thermally stratified mixtures under homogeneous charge compression ignition (HCCI) conditions. For this purpose, the CMC model is applied to two sets of direct numerical simulations (DNSs) modelling ignition of lean n-heptane/air and iso-octane/air mixtures with various levels of thermal stratification. The results show excellent agreement for all n-heptane cases with thermal stratification of 15-60 K. However, an advanced ignition is predicted by the CMC model for the iso-octane case with thermal stratification of 60 K in comparison with the DNS data. Inspection of homogeneous ignition delay demonstrates that the ignition delay time fluctuations are much higher in the iso-octane cases compared with the n-heptane cases having same level of temperature inhomogeneities. This is because of the differing ignition responses to temperature between these two fuels. The observed discrepancies in the iso-octane case with (Formula presented.) K are due to the dominance of deflagration mode of combustion resulting in large conditional fluctuations, which occurs in the iso-octane case and not the n-heptane case because the temperature dependence of ignition delay is stronger for iso-octane. To further investigate the reasons for the observed discrepancies, a transport equation for the conditional variance is derived for premixed combustion. Assessment of the conditional variance equation using the DNS data shows that correlations between dissipation and conditional fluctuation and correlations between reaction and conditional fluctuations are the dominant sources of conditional fluctuations.close0
A Conditional Moment Closure Study of Chemical Reaction Source Terms in SCCI Combustion
No full textThe objective of this study is to evaluate conditional moment closure (CMC) approaches to model chemical reaction rates in compositionally stratified, autoigniting mixtures, in thermochemical conditions relevant to stratified charge compression ignition (SCCI) engines. First-order closure, second-order closure and double conditioning are evaluated and contrasted as options in comparison to a series of direct numerical simulations (DNSs). The two-dimensional (2D) DNS cases simulate ignitions in SCCI-like thermochemical conditions with compositionally stratified n-heptane/air mixtures in a constant volume. The cases feature two different levels of stratification with three mean temperatures in the negative-temperature coefficient (NTC) regime of ignition delay times. The first-order closure approach for reaction rates is first assessed using hybrid DNS-CMC a posteriori tests when implemented in an open source computational fluid dynamics (CFD) package known as OpenFOAMR. The hybrid DNS-CMC a posteriori tests are not a full CMC but a DNS-CMC hybrid in that they compute the scalar and velocity fields at the DNS resolution, thus isolating the first-order reaction rate closure model as the main source of modelling error (as opposed to turbulence model, scalar probability density function model, and scalar dissipation rate model). The hybrid DNS-CMC a posteriori test reveals an excellent agreement between the model and DNS for the cases with low levels of stratification, whereas deviations from the DNS are observed in cases which exhibit high level of stratifications. The a priori analysis reveals that the reason for disagreement is failure of the first-order closure hypothesis in the model due to the high level of conditional fluctuations. Second-order and double conditioning approaches are then evaluated in a priori tests to determine the most promising path forwards in addressing higher levels of stratification. The a priori tests use the DNS data to compute the model terms, thus directly evaluating the model assumptions. It is shown that in the cases with a high level of stratification, even the second-order estimation of the reaction rate source term cannot provide a reasonably accurate closure. Double conditioning using mixture-fraction and sensible enthalpy, however, provides an accurate first-order closure to the reaction rate source term
On the example of Mohsen Makhmalbaf's method
No full textTato odborná práce si klade za cíl představit na příkladu metody renomovaného filmaře Mohsena Makhmalbafa různé přístupy ke vzdělávání v oblasti filmového umění. Práce rovněž nastíní další alternativní přístupy ke vzdělávání v dané oblasti, jak v zahraničí, tak v ČR. Autorka se ve své práci zamýšlí nad tím, jaké vzdělání je pro budoucího filmaře důležité a jakou roli v rámci všech dostupných možností dnes ještě hrají klasické filmové univerzity. Jedná se o odbornou esej, která jako primární zdroj využívá autorčiny rozhovory s Mohsenem Makhmalbafem a jedním z jeho studentů. Na základě dalších rešerší, svých vlastních zkušeností a rovněž pomocí komparace předkládá autorka vlastní odborný názor na danou problematiku.This M.A. thesis aims to introduce alternative ways of education in the field of film art on the methods of a renowned filmmaker Mohsen Makhmalbaf. The thesis also outlines other alternative ways of education in the Czech Republic and other countries. The author reflects the importance of the education for the upcoming filmmakers and what role the traditional film schools have in the spectrum of available possibilities. The prime sources of this essay are two author's interviews; with Mohsen Makhmalbaf and one of his students. Based on other researches, her own experience and also comparation the author expresses her own opinion on the researched problematics
Yukawa textures from singular spectral data
No full text© 2021, The Author(s).The Yukawa textures of effective heterotic models are studied by using singular spectral data. One advantage of this approach is that it is possible to dissect the cohomologies of the bundles into smaller parts and identify the pieces that contain the zero modes, which can potentially have non-zero Yukawa couplings. Another advantage is the manifest relationship between the Yukawa textures in heterotic models and local F-theory models in terms of fields living in bulk or localized inside the 7-branes. We only work with Weierstrass elliptically fibered Calabi-Yau manifolds here. The idea for generalizing this approach to every elliptically fibered Calabi-Yau with rational sections is given at the end of this paper.11Nsciescopu
FIGURES 14–20 in A new species of Macrosiphoniella and redescription of Coloradoa heinzei (Hemiptera: Sternorrhyncha: Aphididae) as a new record in Iran
No full textFIGURES 14–20. Coloradoa heinzei, Apterous viviparous female: 14, dorsal and ventral surface of head; 15, siphunculus (SIPH); 16, cauda; 17, ultimate rostral segment (URS); 18, antenna; 19, dorsal abdominal hairs; 20, hind tarsi. Scale bars, 0.1 mm. Scale bars A for Figs. 14 & 18 and B for Figs. 15–17, 19 & 20. (Drawn by senior author).Published as part of Mehrparvar, Mohsen & Rezwani, Ali, 2007, A new species of Macrosiphoniella and redescription of Coloradoa heinzei (Hemiptera: Sternorrhyncha: Aphididae) as a new record in Iran, pp. 61-68 in Zootaxa 1634 on page 66, DOI: 10.5281/zenodo.17947
Methodology of Research Syntheses in CALL
No full text[EN] The authors of this paper have shared insights from their recent publications in two prestigious journals to draw attention to the need for good practices in conducting syntheses in CALL. The first author discusses 148 high-visibility journal articles on data-driven learning and looks at how such papers can be analyzed as a corpus to complement and refine themes detected from traditional coding (Boulton & Vyatkina, 2024). Keywords/n-grams and distributions in the past five years have evolved over time, especially regarding methodology. The second author investigates high-impact papers published in four major CALL journals to trace the evolution of the field (Choubsaz et al., 2024). The focus is on how Google Scholar citation metrics are adopted to assess the impact of papers and thus assist the authors in narrowing down a large corpus to a manageable dataset. The third author discusses two major synthetic studies (Gillespie, 2020; the second in preparation), which are seen as significant in detecting key historical trends of research development in CALL and in revealing areas that are under-researched. Finally, the fourth author reports on a scientometric analysis of 4,631 CALL articles published across 63 journals (Mohsen et al., 2024). The research identifies the most prevalent research themes using reference co-citation analysis and investigates the most influential publication sources through source co-citation analysis.Choubsaz, Y.;Boulton, A.;Gillespie, J.;Mohsen, MA. (2024). Methodology of Research Syntheses in CALL. Editorial Universitat Politècnica de València. https://doi.org/10.4995/EuroCALL2024.2024.19070OC
Qualitative Evidence Synthesis of Juiciness Components in Educational Game Design: A Thematic Meta-Synthesis Using the MDA Framework
No full textProtocol Title
Qualitative Evidence Synthesis of Juiciness Components in Educational Game Design:
A Thematic Meta-Synthesis Using the MDA Framework
Authors
Mohsen Rahimbeigi¹, Yousef Mahdavinasab¹, Masoumeh Sadat Abtahi¹, Mahdi Ashoori¹
¹ Department of Educational Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Retrospective Registration Date
5 December 2025
Registration Platform
Open Science Framework (OSF)
Review Questions
RQ1: What are the primary components of juiciness in educational games?
RQ2: How do these components distribute across the Mechanics, Dynamics, and Aesthetics layers of the MDA framework?
RQ3: What empirical evidence exists regarding the impact of juiciness components on learner engagement, motivation, and educational outcomes?
Eligibility Criteria – Inclusion
- Peer-reviewed empirical studies (quantitative, qualitative, mixed-methods)
- Explicitly examine or implement juiciness-related elements in educational/serious games
- Published in English, 2004–2024
- Full-text accessible
Eligibility Criteria – Exclusion
- Entertainment-only games
- Purely theoretical/conceptual papers without primary data
- Narrative reviews, editorials, position papers
- Quantitative/mixed-methods studies with n < 10
- Invalid or unreported measurement tools
- Inaccessible full texts
Information Sources
Scopus, ScienceDirect, Emerald Insight (searched up to 31 December 2024)
Search Strategy
("educational game*" OR "serious game*" OR "game-based learning") AND
("juiciness" OR "game feel" OR "excessive positive feedback" OR "sensory polish" OR "juicy design" OR "engagement" OR "immersion" OR "flow")
Study Selection & Data Extraction
Two-stage screening (title/abstract → full-text) by at least two independent reviewers
Synthesis Method
Seven-step qualitative meta-synthesis (Sandelowski & Barroso, 2007) with thematic analysis and mapping onto the MDA framework (Hunicke et al., 2004)
Quality Appraisal
Design-specific Joanna Briggs Institute (JBI) critical appraisal checklists; only studies scoring ≥70% retained
Reporting Guideline
PRISMA 2020 (Page et al., 2021)
Corresponding Author
Mohsen Rahimbeigi
Email: [email protected]
FIGURES 1–13 in A new species of Macrosiphoniella and redescription of Coloradoa heinzei (Hemiptera: Sternorrhyncha: Aphididae) as a new record in Iran
No full textFIGURES 1–13. Macrosiphoniella kermanensis sp. nov., 1–8 & 12, Apterous viviparous female: 1, dorsal and ventral surface of head; 2, ultimate rostral segment (URS); 3, hind tarsi; 4, cauda; 5, antennal segment III (ANTIII); 6, antennal segment IV (ANTIV); 7, antennal segment V (ANTV); 8, antennal segment VI (ANTVI); 12, siphunculus (SIPH). 9–11 & 13, Alate viviparous female: 9, antennal segment III (ANTIII); 10, antennal segment IV (ANTIV); 11, antennal segment V (ANTV); 13, siphunculus (SIPH). Scale bars, 0.1 mm for Figs. 2&3 and 0.3 mm for Figs. 1 & 4–13. (Drawn by senior author).Published as part of Mehrparvar, Mohsen & Rezwani, Ali, 2007, A new species of Macrosiphoniella and redescription of Coloradoa heinzei (Hemiptera: Sternorrhyncha: Aphididae) as a new record in Iran, pp. 61-68 in Zootaxa 1634 on page 63, DOI: 10.5281/zenodo.17947
Redistribution of garbage codes to underlying causes of death: a systematic analysis on Italy and a comparison with most populous Western European countries based on the Global Burden of Disease Study 2019 (Jan, 10.1093/eurpub/ckab194, 2022)
No full textIn the originally published version of this manuscript, an author was erroneously omitted from the list of authors. The list should read:
“Lorenzo Monasta, Gianfranco Alicandro, Maja Pasovic, Matthew Cunningham, Benedetta Armocida, Christopher J L Murray, Luca
Ronfani, Mohsen Naghavi, GBD 2019 Italy Causes of Death Collaborators” instead of “Lorenzo Monasta, Gianfranco Alicandro, Maja
Pasovic, Matthew Cunningham, Benedetta Armocida, Luca Ronfani, Mohsen Naghavi, GBD 2019 Italy Causes of Death Collaborators”. This
error has been corrected online
Degrees of Kalman varieties of tensors
No full textFunding Information: The idea of this project was conceived during Shahidi's postdoc at Università di Firenze. We thank Giorgio Ottaviani for very useful discussions and encouragement. We thank Jan Draisma for explaining to us a way of deriving the equations in Example 41 . The first author thanks Dr. Alireza Firoozfar and Dr. Mohsen Afsharchi for their support. The second author is partially supported by the Academy of Finland Grant 323416 . During most of the preparation of the manuscript, the third author was a postdoc at Universität Bern, supported by Vici Grant 639.033.514 of Jan Draisma from the Netherlands Organisation for Scientific Research . We thank two anonymous referees for their useful comments and questions that also helped to improve the presentation. Publisher Copyright: © 2022 The Author(s)Kalman varieties of tensors are algebraic varieties consisting of tensors whose singular vector k-tuples lay on prescribed subvarieties. They were first studied by Ottaviani and Sturmfels in the context of matrices. We extend recent results of Ottaviani and the first author to the partially symmetric setting. We describe a generating function whose coefficients are the degrees of these varieties and we analyze its asymptotics, providing analytic results à la Zeilberger and Pantone. We emphasize the special role of isotropic vectors in the spectral theory of tensors and describe the totally isotropic Kalman variety as a dual variety.Peer reviewe
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