scholarly journals Fluid Dynamics in Curvilinear Coordinates without Fictitious Forces

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 366
Author(s):  
Christian Y. Cardall
Keyword(s):  
Fluid Dynamics ◽  
Geometric Approach ◽  
Three Dimensions ◽  
Curvilinear Coordinates ◽  
Conservative Form ◽  
Insight Into

The use of curvilinear coordinates is sometimes indicated by the inherent geometry of a fluid dynamics problem, but this introduces fictitious forces into the momentum equations that spoil the strict conservative form. If one is willing to work in three dimensions, these fictitious forces can be eliminated by solving for rectangular (Cartesian) momentum components on a curvilinear mesh. A thoroughly geometric approach to fluid dynamics on spacetime demonstrates this transparently, while also giving insight into a greater unity of the relativistic and nonrelativistic cases than is usually appreciated.

Solution of Navier’s Equation in Cylindrical Curvilinear Coordinates

1978 ◽  
Vol 45 (4) ◽  
pp. 812-816 ◽  
Author(s):  
B. S. Berger ◽  
B. Alabi
Keyword(s):  
Fourier Transform ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Half Space ◽  
Coordinate Transformation ◽  
Numerical Results ◽  
Three Dimensions ◽  
Curvilinear Coordinates ◽  
Rectangular Region

A solution has been derived for the Navier equations in orthogonal cylindrical curvilinear coordinates in which the axial variable, X3, is suppressed through a Fourier transform. The necessary coordinate transformation may be found either analytically or numerically for given geometries. The finite-difference forms of the mapped Navier equations and boundary conditions are solved in a rectangular region in the curvilinear coordinaties. Numerical results are given for the half space with various surface shapes and boundary conditions in two and three dimensions.

scholarly journals On numerical solver selection and related uncertainty terminology

2009 ◽  
Vol 12 (3) ◽  
pp. 241-250 ◽  
Author(s):  
Petra Claeys ◽  
Ann van Griensven ◽  
Lorenzo Benedetti ◽  
Bernard De Baets ◽  
Peter A. Vanrolleghem
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Models ◽  
Process Design ◽  
Uncertainty Assessment ◽  
Environmental Modelling ◽  
Chemical Systems ◽  
The Past ◽  
Numerical Solver ◽  
Physical And Chemical ◽  
Insight Into

Mathematical models provide insight into numerous biological, physical and chemical systems. They can be used in process design, optimisation, control and decision support, as acknowledged in many different fields of scientific research. Mathematical models do not always yield reliable results and uncertainty should be taken into account. At present, it is possible to identify some factors contributing to uncertainty, and the awareness of the necessity of uncertainty assessment is rising. In the fields of Environmental Modelling and Computational Fluid Dynamics, for instance, terminology related to uncertainty exists and is generally accepted. However, the uncertainty due to the choice of the numerical solver and its settings used to compute the solution of the models did not receive much attention in the past. A motivating example on the existence and effect of numerical uncertainty is provided and clearly shows that we can no longer ignore it. This paper introduces a new terminology to support communication about uncertainty caused by numerical solvers, so that scientists become perceptive to it.

scholarly journals Vulnerability among European Youth: A Proposal for a Multidimensional Approach (2013–2017)

2021 ◽  
Vol 13 (16) ◽  
pp. 9252
Author(s):  
Álvaro Moro ◽  
Concepción Maiztegui-Oñate ◽  
Josu Solabarrieta
Keyword(s):  
Inclusive Education ◽  
Secondary Analysis ◽  
Cultural Dimensions ◽  
Multidimensional Analysis ◽  
Three Dimensions ◽  
Vulnerable Groups ◽  
Multidimensional Approach ◽  
Policy Debates ◽  
European Youth ◽  
Insight Into

The notion of vulnerability has acquired an important role in social policy debates. Therefore, the identification of vulnerable groups and their conditions is particularly important for the orientation of public policies and risk reduction. This article aims to offer a broad vision of the situation of European youth (15–29) using three dimensions of vulnerability (personal, economic and socio-cultural dimensions). To do so, we developed a multidimensional approach combining a system of indicators (N = 33) to contrast the evolution of the aforementioned dimensions among the European countries. Based on secondary analysis of quantitative data on European member states, we compared the evolution during two moments in time. The first period examined was 2012–2014, after the global financial crises but prior to the implementation of Youth Guarantee, whereas the second was the period which allowed for an examination of the latest updated data available (2017). Our results confirm territorial imbalances that affect the lives of European youth and their future opportunities. Northern countries led this scenario combining an inclusive education system with supportive labor market policies offering more opportunities to overcome risks. Although this multidimensional analysis is exploratory, its findings provide preliminary insight into the configuration of the dimensions of vulnerability in European youth.

scholarly journals The House of Marie Shannon

2021 ◽  
Author(s):  
◽  
Sally Margaret Apthorp
Keyword(s):  
Three Dimensional ◽  
Two Dimensions ◽  
Domestic Architecture ◽  
Three Dimensions ◽  
Camera Obscura ◽  
Architectural Space ◽  
Domestic Lives ◽  
Architectural Tradition ◽  
Light And Shadow ◽  
Insight Into

<p>This thesis creatively explores the architectural implications present in the photographs by New Zealand photographer Marie Shannon. The result of this exploration is a house for Shannon. The focus is seven of Shannon's interior panoramas from 1985-1987 in which architectural space is presented as a domestic stage. In these photograph's furniture and objects are the props and Shannon is an actress. This performance, with Shannon both behind and in front of her camera, creates a double insight into her world; architecture as a stage to domestic life, and a photographers view of domestic architecture. Shannon's view on the world enables a greater understanding to our ordinary, domestic lives. Photography is a revealing process that teaches us to see more richly in terms of detail, shading, texture, light and shadow. Through an engagement with photographs and understanding architectural space through a photographer's eye, the hidden, secret or unnoticed aspects to Shannon's reality will be revealed. This insight into another's reality may in turn enable a deeper understanding of our own. The methodology was a revealing process that involved experimenting with Shannon's panoramic photographs. Models and drawing, through photographic techniques, lead to insights both formally in three dimensions and at surface level in two dimensions. These techniques and insights were applied to the site through the framework of a camera obscura. Shannon's new home is created by looking at her photographs with an architect's 'eye'. Externally the home acts as a closed vessel, a camera obscura. But internally rich and intriguing forms, surfaces, textures and shadings are created. Just as the camera obscura projects an exterior scene onto the interior, so does the home. Shannon will inhabit this projection of the shadows which oppose 30 O'Neill Street, Ponsonby, Auckland; her past home and site of her photographs. Photographers, and in particular Shannon, look at the architectural world with fresh eyes, free from an architectural tradition. Photography and the camera enable an improved power of sight. More is revealed to the camera. Beauty is seen in the ordinary, with detail, tone, texture, light and dark fully revealed. As a suspended moment, a deeper understanding and opportunity is created to observe and appreciate this beauty. Through designing with a photographer's eye greater insight is gained into Shannon's 'reality'. This 'revealing' process acts as a means of teaching us how to see pictorial beauty that is inherent in our ordinary lives. This is the beauty that is often hidden in secret, due to our unseeing eyes. This project converts the photographs beauty back into three dimensional architecture.</p>

scholarly journals Intestinal organoids for modelling intestinal development and disease

2018 ◽  
Vol 373 (1750) ◽  
pp. 20170217 ◽  
Author(s):  
Kathryn L. Fair ◽  
Jennifer Colquhoun ◽  
Nicholas R. F. Hannan
Keyword(s):  
Gastrointestinal Disease ◽  
Gastrointestinal Diseases ◽  
Developed Countries ◽  
Three Dimensions ◽  
Intestinal Development ◽  
Culture Techniques ◽  
Intestinal Organoids ◽  
Insight Into ◽  
Human Specific

Gastrointestinal diseases are becoming increasingly prevalent in developed countries. Immortalized cells and animal models have delivered important but limited insight into the mechanisms that initiate and propagate these diseases. Human-specific models of intestinal development and disease are desperately needed that can recapitulate structure and function of the gut in vitro . Advances in pluripotent stem cells and primary tissue culture techniques have made it possible to culture intestinal epithelial cells in three dimensions that self-assemble to form ‘intestinal organoids'. These organoids allow for new, human-specific models that can be used to gain insight into gastrointestinal disease and potentially deliver new therapies to treat them. Here we review current in vitro models of intestinal development and disease, considering where improvements could be made and potential future applications in the fields of developmental modelling, drug/toxicity testing and therapeutic uses. This article is part of the theme issue ‘Designer human tissue: coming to a lab near you'.

scholarly journals The financialisation of urban infrastructure: A framework of analysis

Urban Studies ◽  
2018 ◽  
Vol 56 (7) ◽  
pp. 1304-1325 ◽  
Author(s):  
Phillip O’Neill
Keyword(s):  
New York ◽  
Capital Structure ◽  
Balance Sheet ◽  
Urban Infrastructure ◽  
Three Dimensions ◽  
Financial Asset ◽  
Organisational Structure ◽  
Regulatory Structure ◽  
Infrastructure Investments ◽  
Insight Into

The literature on the financialisation of urban infrastructure typically traces how an infrastructure asset’s balance sheet is (re)engineered to create a financial asset. What the literature neglects are the processes by which an asset generates urban flows. Attention to these processes, we argue, not only gives better insight into the processes of financialisation of infrastructure but also exposes how the act of financing affects the operations of cities through its influence on the performance of infrastructure assets. The argument presented in the article is informed by case studies of infrastructure investments revealed in interviews conducted in New York, London and Sydney. This material is drawn on to generate a framework for understanding the relationships between infrastructure investing and the infrastructure-enabled flows of a city. This framework has three dimensions through which the financialisation process is seen to be mediated. These are capital structure, organisational structure and regulatory structure. The article argues that these mezzanine-level conceptualisations enable us to explore the to-and-fro between financing and operating cities. A key proposition is that the physical flows of a city are basic not only to the design and enactment of an investment instrument but also to its financial viability. The realisation of this relationship has changed the way investors approach infrastructure assets as investment products. Implications for urban management are drawn.

scholarly journals Mesoscopic 3D imaging of pancreatic cancer and Langerhans islets based on tissue autofluorescence

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Max Hahn ◽  
Christoffer Nord ◽  
Oskar Franklin ◽  
Tomas Alanentalo ◽  
Martin Isaksson Mettävainio ◽  
...  
Keyword(s):  
Light Sheet ◽  
Pancreatic Tissue ◽  
Three Dimensions ◽  
Ductal Adenocarcinoma ◽  
Resection Margins ◽  
Histopathological Analysis ◽  
Islet Mass ◽  
Optical Projection ◽  
3D Microenvironment ◽  
Insight Into

Abstract The possibility to assess pancreatic anatomy with microscopic resolution in three dimensions (3D) would significantly add to pathological analyses of disease processes. Pancreatic ductal adenocarcinoma (PDAC) has a bleak prognosis with over 90% of the patients dying within 5 years after diagnosis. Cure can be achieved by surgical resection, but the efficiency remains drearily low. Here we demonstrate a method that without prior immunohistochemical labelling provides insight into the 3D microenvironment and spread of PDAC and premalignant cysts in intact surgical biopsies. The method is based solely on the autofluorescent properties of the investigated tissues using optical projection tomography and/or light-sheet fluorescence microscopy. It does not interfere with subsequent histopathological analysis and may facilitate identification of tumor-free resection margins within hours. We further demonstrate how the developed approach can be used to assess individual volumes and numbers of the islets of Langerhans in unprecedently large biopsies of human pancreatic tissue, thus providing a new means by which remaining islet mass may be assessed in settings of diabetes. Generally, the method may provide a fast approach to provide new anatomical insight into pancreatic pathophysiology.

An Accurate and Efficient Euler Solver for Three-Dimensional Turbomachinery Flows

1986 ◽  
Author(s):  
C. F. Shieh ◽  
R. A. Delaney
Keyword(s):  
Numerical Solution ◽  
Euler Equations ◽  
Numerical Scheme ◽  
Three Dimensional ◽  
Curvilinear Coordinates ◽  
Analysis Method ◽  
Surfaces Of Revolution ◽  
Conservative Form ◽  
Turbine Cascades ◽  
Euler Solver

Accurate and efficient Euler equation numerical solution techniques are presented for analysis of three-dimensional turbomachinery flows. These techniques include an efficient explicit hopscotch numerical scheme for solution of the 3-D time-dependent Euler equations and an O-type body-conforming grid system. The hopscotch scheme is applied to the conservative form of the Euler equations written in general curvilinear coordinates. The grid is constructed by stacking from hub to shroud 2-D O-type grids on equally spaced surfaces of revolution. Numerical solution results for two turbine cascades are presented and compared with experimental data to demonstrate the accuracy of the analysis method.

scholarly journals What national governance codes say about corporate culture

2020 ◽  
Vol 20 (5) ◽  
pp. 903-917
Author(s):  
Marie-Fleur Lobrij ◽  
Muel Kaptein ◽  
Mijntje Lückerath-Rovers
Keyword(s):  
Corporate Governance ◽  
Corporate Culture ◽  
Text Analysis ◽  
Design Methodology ◽  
Three Dimensions ◽  
Analysis Program ◽  
Content Type ◽  
Corporate Governance Codes ◽  
Computer Aided ◽  
Insight Into

Purpose This study aims to provide insight into the current incorporation of corporate culture in national corporate governance codes. The authors identify three levels of incorporation for each of the following three dimensions: layers of corporate culture (the “what”), the alignment of corporate culture in the organization (the “for whom”) and the board’s roles regarding corporate culture (the “how”). Design/methodology/approach To assess the extent to which national codes have incorporated corporate culture, the authors used a sample of 88 national corporate governance codes. The authors performed a content analysis of these codes using a computer-aided text analysis program. The first step involved the identification of dimensions of corporate culture per national code. These dimensions were then assessed based on three levels of incorporation. Finally, the authors ranked national codes with similar levels of incorporation per dimension and aggregated the dimensions. Findings The data show that five of the 88 national corporate governance codes that the authors analysed scored the highest level in all three dimensions of corporate culture. Originality/value This is the first study to provide an overview of what national corporate governance codes say about corporate culture. The authors address two gaps in the existing literature. First, the authors develop and use a richer conceptualization of how corporate culture can be addressed in national corporate governance codes. Second, the authors analyse these corporate governance codes worldwide.

scholarly journals Surface effects at the nanoscale based on Gurtin’s theory: a review

2014 ◽  
Vol 23 (5-6) ◽  
pp. 141-151 ◽  
Author(s):  
Jianlin Liu ◽  
Runni Wu ◽  
Re Xia
Keyword(s):  
Mechanical Response ◽  
Surface Elasticity ◽  
Surface Effects ◽  
Three Dimensions ◽  
Valuable Insight ◽  
Micro Electro Mechanical Systems ◽  
Nanoscale Solids ◽  
Simulation And Experiment ◽  
Elastic And Plastic Deformation ◽  
Insight Into

AbstractThe fields of nanotechnology and nanoscience are full of opportunities and challenges. The needed modification of classical continuum mechanics to account for the dramatically novel characteristics and phenomena determining the mechanical response of nanomaterials/structures remains an ambitious goal pursued by mechanics researchers. The theory of surface elasticity proposed by Gurtin and Murdoch has been shown to be an important tool in theoretical nanomechanics. In this paper, we present an overview of recent advances in application of surface elasticity theory at the nanoscale. In particular, we focus on the elastic and plastic deformation, vibration and buckling, fracture and contact behavior of nanoscale solids from one dimension to three dimensions. We hope that this contribution can provide a valuable insight into nanomechanics analysis methods by taking surface effects into account. The results may help to bridge the gap between conventional mechanics and findings from simulation and experiment, in such areas as multifunctional material and micro-electro-mechanical systems.

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