101 research outputs found
CFD modeling of natural gas engine combustion with a flame area evolution model
No full textA detailed description of the combustion process is fundamental in modern spark-ignition (SI) engines to guarantee control of pollutants formation and to meet future emission standards. Within this context, computational fluid dynamics (CFD) simulations represent an efficient and powerful tool to understand the different involved phenomena as mixture ignition, combustion development and pollutant formation. Object of this work is to find a CFD methodology to model premixed natural gas light-duty SI engines. The ignition stage is modeled by means of a simplified Eulerian spherical kernel approach (deposition model). Then, turbulent flame propagation is reproduced by means of two variables (regress variable and flame wrinkling factor) as proposed by Weller. Laminar to turbulent flame transition is taken into account using Herweg and Maly formulation and a zero-dimensional flame kernel radius evolution. Tabulated kinetics is used to estimate chemical composition of burned gases and to speed up the simulation since no chemical equilibrium calculations are necessary. The proposed CFD methodology was validated with experimental data of in-cylinder pressure, heat release rate and gross indicated work at different loads and speeds
CFD modeling of combustion of a natural gas Light-Duty Engine
No full textA CFD methodology to model natural gas Light-Duty SI (Spark-Ignition) engines is here proposed. The ignition stage is modeled by means of a simplified Eulerian spherical kernel approach (deposition model). Then, the fully turbulent flame propagation is reproduced by the Coherent Flamelet Model (CFM), where turbulence effects are taken into account by considering the flame surface density evolution. The laminar to turbulent flame transition is managed by the CFM model and it is assumed to occur when the flame radius reaches a fraction of the integral length scale. This methodology was validated with experimental data of in-cylinder pressure and heat release rate at different loads and speeds
Assessment of insurance risks in the compulsory crop insurance
No full textThis article is an analysis of the issue insurance risks from the point of view of the subjective scope, and of the mandatory crop insurance in the Polish legal system. The issues raised as an element of introduced within the framework of the Common Agricultural Policy for the years 2014-2020 of the system of risk management in agriculture determine the direction of the development of crop insurance as a tool for securing not only the interests of agricultural producers, but also entities in any way dependent on the economic situation of agriculture as a sector of economy. At the same time, the author points to the issues specific to individual insurance risks, as well as to questions of interpretation arising under these regulations. The author also draws attention to the achievements of home insurance legislation in the matter, reaching the beginning of the reborn Polish State, as well as the development trends in the market of compulsory insurance of agricultural crops in Poland, from the perspective of its functioning after Poland’s accession to the European Union.Uniwersytet ŚląskiFendler Z., Prywatne prawo ubezpieczeniowe wraz z komentarzem i orzecznictwem sądów polskich, Kraków 1934.Fuchs D., Zakres obowiązku prewencji w prawie ubezpieczeń gospodarczych. Uwagi na tle art. 826 k.c., „Prawo Asekuracyjne” 2004, nr 2.Kamiński T., Likwidacja szkód w uprawach, [w:] Ubezpieczenia produkcji roślinnej w Polsce, M. Kaczała, K. Rojewski (red.), Warszawa 2015.Kowalewski E., Prawo ubezpieczeń gospodarczych, Bydgoszcz – Toruń 2002.Łyskawa K., Rojewski K., Kategorie zagrożeń i ryzyko w działalności rolniczej – szczególnie w produkcji rolnej, [w:] Ubezpieczenia produkcji roślinnej w Polsce, M. Kaczała, K. Rojewski (red.), Warszawa 2015.Nawracała J., [w:] Prawo ubezpieczeń gospodarczych, Komentarz tom I, Z. Brodecki, M. Serwach, M. Glicz (red.), Warszawa 2010.Orlicki M., Ubezpieczenia Obowiązkowe, Warszawa 2011.Serwach M., [w:] Ryzyko ubezpieczeniowe, Wybrane zagadnienia teorii i praktyki, M. Serwach (red.), Łódź 2013.Wąsiewicz A., Umowa ubezpieczenia, [w:] A. Wąsiewicz (red.), Ubezpieczenia w gospodarce rynkowej t. 3, Bydgoszcz 1997.373-3881437338
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Uncovering the truth behind Vygotsky's cognitive apprenticeship: engaging reflective practitioners in the 'master-apprentice' relationship
No full textIn recent years theories of situated cognition sharing the idea that learning and doing are inseparable as part of a process of enculturation, largely based upon the work of Vygotsky in developing a model of ‘cognitive apprenticeship’, have received much attention in education (Vygotsky, 1978) as an insightful model underpinning forms of learning and teaching. The master-apprentice relationship using techniques of apprenticeship such as modelling, scaffolding and reflection has since been used as a base for considerable research helping researchers and practitioners to understand teacher-student action across a range of different teaching situations (Collins et al., 1989; Hennessy, 1993; Jarvela, 1995; Rojewski et al., 1994). The focus of much of this research has explored the efficacy of the model when set against the question of how to improve forms of learning and teaching in particular settings
Mershon Center Research Digest 2004-05
No full textThe University Archives has determined that this item is of continuing value to OSU's history.Mershon Center Research Digest describing Mershon research projects in 2004-05Mershon Center for International Security StudiesBruce A. Weinberg, Alexander Thompson, Alexander Stephan, Allan Silverman, Clarissa Hayward, Michael Neblo, John Parrish, Jennifer Siegel, Cathy Rakowski, Pamela Paxton, Geoffrey Parker, Mineharu Nakayama, Allan R. Millett, Harwood K. McClerking, R. William Liddle, Mitchell B. Lerner, Peter L. Hahn, Marcus J. Kurtz, Sally Kitch, Margaret Mills, John Kagel, J. Craig Jenkins, Fred J. Hitzhusen, Stephen J. Scanlan, Amy Horowitz, Tamar Rudavsky, Holger H. Herwig, Richard F. Hamilton, Richard Gunther, José Ramó Montero, Mark Grimsley, Timothy B. Frye, Eric Fisher, Carole K. Fink, Carter V. Findley, Robert C. Davis, Kevin R. Co
Pressure-Induced Excitations in the Out-of-Plane Optical Response of the Nodal-Line Semimetal ZrSiS
No full textThe anisotropic optical response of the layered, nodal-line semimetal ZrSiS at ambient and high pressure is investigated by frequency-dependent reflectivity measurements for the polarization along and perpendicular to the layers. The highly anisotropic optical conductivity is in very good agreement with results from density-functional theory calculations and confirms the anisotropic character of ZrSiS. Whereas the in-plane optical conductivity shows only modest pressure-induced changes, we found strong effects on the out-of-plane optical conductivity spectrum of ZrSiS, with the appearance of two prominent excitations. These pronounced pressure-induced effects can neither be attributed to a structural phase transition according to our single-crystal x-ray diffraction measurements, nor can they be explained by electronic correlation and electron-hole pairing effects, as revealed by theoretical calculations. Our findings are discussed in the context of the recently proposed excitonic insulator phase in ZrSiS
Osteoarthritic Milieu Affects Adipose-Derived Mesenchymal Stromal Cells
No full textThe objective of this study was to define the effects of osteoarthritic (OA) milieu on good manufactured practice-adipose-derived mesenchymal stromal cells (GMP-ASC) that are commonly utilized in cell therapies. Two different OA milieu: OA synovial fluid (SF) and OA-conditioned medium (CM) from synoviocytes were used to treat GMP-ASC both in normoxia or hypoxia. GMP-ASC were tested for cell migration, proliferation, cytokine receptors expression (CXCR1, CXCR2, CXCR3, CXCR4, CXCR7, CCR1, CCR2, CCR3, CCR5, IL6R), and cytokines (CXCL8/IL8, CXCL10/IP10, CXCL12/SDF-1, CCL2/MCP1, CCL3/MIP1α, CCL4/MIP1β, CCL5/RANTES, IL6) release. Healthy SF was used as controls. We demonstrated that GMP-ASC show an increase in proliferation, migration, and modulation of CXCR1, CXCR3, CCR1, and CCR5 receptors in hypoxic condition. Moreover, GMP-ASC migration increased 15-fold when treated either with OA-SF or OA-CM compared with healthy SF both in normoxia and hypoxia. GMP-ASC treated in both OA milieu showed an increase in CXCR3, CCR3, and IL6R and a decrease in CCR1 and CCR2 receptors. In OA-SF, we detected higher amount of CXCL10/IP10 than in OA-CM, while CCL2/MCP1 and CCL4/MIP1β were higher in OA-CM compared with OA-SF. CXCL10/IP10 was the only chemokine of the OA milieu, which was down-modulated after treatment with GMP-ASC. In conclusion, we demonstrated specific effects of OA milieu on both GMP-ASC proliferation, migration, and cytokine receptor expression that were strictly dependent on the inflammatory and hypoxic environment. The use of characterized OA milieu is crucial to define the therapeutic effect of GMP-ASC and indicates that CXCL10/IP10–CXCR3 axis is partially involved in the GMP-ASC effect on synovial macrophages. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:336-347, 2020
The Role of Computerisation in the Development of an Efficient Judiciary and Administration on the Example of the National Court Register and Land and Mortgage Registers
No full textAutor przedstawia znaczącą rolę informatyzacji w rozwoju sprawnego sądownictwa i administracji na przykładzie Krajowego Rejestru Sądowego i ksiąg wieczystych. W Polsce to jedno z największych osiągnięć wymiaru sprawiedliwości XXI wieku. Autor wskazuje zasady prowadzenia ksiąg wieczystych: zasadę jawności formalnej ksiąg wieczystych, zasadę domniemania zgodności ze stanem prawnym, zasadę przyrzeczenia wiary publicznej oraz zasadę pierwszeństwa praw. W związku z tym autor koncentruje się na księgach wieczystych w systemie informatycznym. Rozwiązanie to umożliwia bezpośredni dostęp do ksiąg wieczystych osobom zainteresowanym wydaniem odpisów. Co więcej, dostęp do ksiąg wieczystych jest możliwy za pośrednictwem Internetu (odpowiednia strona internetowa). Przedstawiono również funkcjonowanie Krajowego Rejestru Sądowego w systemie informatycznym.The author presents the significant role of computerisation in the development of an efficient judiciary and administration on the example of the National Court Register and land and mortgage registers. In Poland, it is one of the biggest achievements of justice in the XXI century. The author indicates the principles of land and mortgage registers: the principle of openness of the formal land and mortgage registers, the principle of presumption of conformity with the legal status, the principle of pledge of public faith and the principle of priority rule rights enshrined. Consequently, the author focuses on the land and mortgage registers in the computer system. This solution enables direct access to the land and mortgage registers for those interested in issuing copies. What is more, access to the land and mortgage registers is possible by using the Internet (proper website). There is also presented functioning of the National Court Register in the computer system.
“Quien será un gran pintor...” Análisis de las condicionantes y de las capacidades necesarias para ser artista según Durero
No full textResumen: La historiografía artística de la Edad Moderna, plasmada en tratados, paragonae, discursos y correspondencias entre humanistas, permite a los historiadores del arte reconstruir y analizar distintos aspectos de la producción artística italiana de esa época. En el caso de los territorios del Norte de Europa, la ausencia de esta documentación no permite precisar con claridad de detalle fenómenos análogos para los pintores flamencos o acerca de la llamada escuela alemana hasta las primeras décadas del siglo XVI. La poca documentación conservada imposibilita una definición profunda de los aspectos teóricos y estéticos ligados a la producción de los artistas. Además, la estructura gremial del Norte disuadía el proceso de individualización de los artistas. Alberto Durero, artista vinculado a la corte de Maximliano I y posteriormente a la corte de Carlos V, se considera el primer autor de tratados teóricos sobre la creación artística al Norte de los Alpes. Gracias a sus viajes a Italia, Durero entró en contacto con las corrientes de pensamiento acerca de la teoría del arte, que le llevaron a redactar varias publicaciones: Proyecto para el tratado sobre la pintura(1508-1513), Los cuatro libros sobre medidas. Instrucciones de medir con compás y regla(1525) y Cuatro libros sobre las proporciones humanas (1528). El objetivo de este estudio es analizar los tres tratados mencionados con una atención especial a las recomendaciones del autor respecto a la formación del artista. A partir del corpus dureriano, traducido por Bialostocki en 1954 ,este estudio permitirá revisar la difusión y aplicación de las sugerencias en el ámbito de los artistas durante las primeras décadas del siglo XVI.Abstract: The artistic historiography of the Modern Age, formed by theoretical treatises, paragonae, speeches and correspondence between humanists, permit the Historians of art to reconstruct and to analyse various aspects of Italian artistic production. In the case of Northern Europe, the absence of that kind of documentation does not allow to precise clear analogous phenomena for Flemish painters or for German school, until the early decades of the sixteenth century. Not much preserved documentation makes impossible to define well theoretical and aesthetic aspects relate to the artistic production. Besides, the guild structure on the Northern Europe dissuades the process of artists individualization. Albrecht Durer, connected to the court of Maximlian I and to the Charles V court artist, is considered as the first author of artistic theoretical treaties on the North of the Alps. Thanks for the trip to Italy, Dürer came into contact with modern art theory, which resulted in writing several treaties: Project for the Treatise on Painting (1508-1513), Four Books on Measurement. Instructions for Measuring with Compass and Ruler (1525) and Four Books on Human Proportion (1528). The aim of this study is to analyse the three mentioned treaties with special attention on the author's recommendations for appropriated formation of the artist. The base is the Durer´s corpus, translated by Bialostocki in 1954. This study will review the dissemination and implementation of Durer´s suggestions for artists during the first decades of the sixteenth century
A Novel 1D Co-Simulation Framework for the Prediction of Tailpipe Emissions under Different IC Engine Operating Conditions
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