Definition of Energy Imparted: A New Formulation Adapted to Exact Solutions of the Absorbed Dose Equation under Nonequilibrium Conditions

1979 ◽  
Vol 77 (2) ◽  
pp. 209 ◽  
Author(s):  
Gudrun Alm Carlsson
Keyword(s):  
Exact Solutions ◽  
Absorbed Dose ◽  
Nonequilibrium Conditions ◽  
Definition Of ◽  
New Formulation

scholarly journals Large-Eddy Simulation Analyses of Heated Urban Canyon Facades

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3078
Author(s):  
Carlo Cintolesi ◽  
Francesco Barbano ◽  
Silvana Di Sabatino
Keyword(s):  
Urban Canopy ◽  
Pollutant Removal ◽  
Present Contribution ◽  
Convective Flows ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Isothermal Case ◽  
Definition Of ◽  
New Formulation ◽  
Heating Up

Thermal convective flows are common phenomena in real urban canyons and strongly affect the mechanisms of pollutant removal from the canyon. The present contribution aims at investigating the complex interaction between inertial and thermal forces within the canyon, including the impacts on turbulent features and pollutant removal mechanisms. Large-eddy simulations reproduce infinitely long square canyons having isothermal and differently heated facades. A scalar source on the street mimics the pollutant released by traffic. The presence of heated facades triggers convective flows which generate an interaction region around the canyon-ambient interface, characterised by highly energetic turbulent fluxes and an increase of momentum and mass exchange. The presence of this region of high mixing facilitates the pollutant removal across the interface and decreases the urban canopy drag. The heating-up of upwind facade determines favourable convection that strengthens the primary internal vortex and decreases the pollutant concentration of the whole canyon by 49% compare to the isothermal case. The heating-up of the downwind facade produces adverse convection counteracting the wind-induced motion. Consequently, the primary vortex is less energetic and confined in the upper-canyon area, while a region of almost zero velocity and high pollution concentration (40% more than the isothermal case) appears at the pedestrian level. Finally, numerical analyses allow a definition of a local Richardson number based on in-canyon quantities only and a new formulation is proposed to characterise the thermo-dynamics regimes.

scholarly journals Formulation of scale transformation in a stochastic data assimilation framework

2017 ◽  
Vol 24 (2) ◽  
pp. 279-291 ◽  
Author(s):  
Feng Liu ◽  
Xin Li
Keyword(s):  
Data Assimilation ◽  
Spatial Scale ◽  
Measure Theory ◽  
Stochastic Calculus ◽  
Scale Transformation ◽  
Earth Observations ◽  
Model Unit ◽  
Stochastic Data ◽  
Definition Of ◽  
New Formulation

Abstract. Understanding the errors caused by spatial-scale transformation in Earth observations and simulations requires a rigorous definition of scale. These errors are also an important component of representativeness errors in data assimilation. Several relevant studies have been conducted, but the theory of the scale associated with representativeness errors is still not well developed. We addressed these problems by reformulating the data assimilation framework using measure theory and stochastic calculus. First, measure theory is used to propose that the spatial scale is a Lebesgue measure with respect to the observation footprint or model unit, and the Lebesgue integration by substitution is used to describe the scale transformation. Second, a scale-dependent geophysical variable is defined to consider the heterogeneities and dynamic processes. Finally, the structures of the scale-dependent errors are studied in the Bayesian framework of data assimilation based on stochastic calculus. All the results were presented on the condition that the scale is one-dimensional, and the variations in these errors depend on the differences between scales. This new formulation provides a more general framework to understand the representativeness error in a non-linear and stochastic sense and is a promising way to address the spatial-scale issue.

Abstract

2014 ◽  
Vol 14 (2) ◽  
pp. 5-5
Keyword(s):  
Three Dimensional ◽  
Absorbed Dose ◽  
Target Volume ◽  
High Dose ◽  
Stereotactic Radiation ◽  
Small Field Dosimetry ◽  
Radiation Delivery ◽  
Target Volumes ◽  
Definition Of ◽  
Three Dimensional Coordinate

Rapid developments in imaging and radiation-delivery technology have fueled the application of small photon beams in stereotactic radiation therapy (SRT). Historically, stereotaxy referred to the use of a three-dimensional coordinate system to localize intracranial targets and has been more recently extensively developed in extracranial clinical situations. SRT involves stereotactic localization techniques combined with the delivery of multiple small photon fields in a few high-dose fractions. In SRT, the therapeutic ratio is optimized through delivery of highly conformal absorbed dose distributions with steep dose fall-off ensuring optimal absorbed dose in the target volume combined with minimal normal-tissue irradiation. Consistent with previous ICRU Reports 50 (ICRU, 1993), 62, (ICRU, 1999), and 83, (ICRU, 2010), this Report recommends a strict definition of target volumes (GTV, CTV) by reviewing imaging modalities used in clinical practice. This Report covers fundamentals of small-field dosimetry, treatment-planning algorithms, commissioning, and quality assurance for the existing delivery systems, as well as the role of image guidance during delivery. Finally, it recommends a framework for prescribing, recording, and reporting stereotactic radiotherapy, and covers most of the pathologies eligible for stereotactic delivery (malignant and non-malignant).

scholarly journals On the relativistic micro-canonical ensemble and relativistic kinetic theory for N relativistic particles in inertial and non-inertial rest frames

2015 ◽  
Vol 12 (04) ◽  
pp. 1550049 ◽  
Author(s):  
David Alba ◽  
Horace W. Crater ◽  
Luca Lusanna
Keyword(s):  
Kinetic Theory ◽  
Canonical Ensemble ◽  
Particle System ◽  
Classical Mechanics ◽  
Canonical Partition Function ◽  
Relativistic Limit ◽  
Relativistic Kinetic Theory ◽  
Definition Of ◽  
New Formulation ◽  
Relativistic Particles

A new formulation of relativistic classical mechanics allows a reconsideration of old unsolved problems in relativistic kinetic theory and in relativistic statistical mechanics. In particular a definition of the relativistic micro-canonical partition function is given strictly in terms of the Poincaré generators of an interacting N-particle system both in the inertial and non-inertial rest frames. The non-relativistic limit allows a definition of both the inertial and non-inertial micro-canonical ensemble in terms of the Galilei generators.

The Zone Method: A New Explicit Matrix Relation to Calculate the Total Exchange Areas in Anisotropically Scattering Medium Bounded by Anisotropically Reflecting Walls

2002 ◽  
Vol 124 (4) ◽  
pp. 696-703 ◽  
Author(s):  
J. M. Goyhe´ne`che ◽  
J. F. Sacadura
Keyword(s):  
Complex Geometry ◽  
Anisotropic Scattering ◽  
Radiative Properties ◽  
Scattering Medium ◽  
Zone Method ◽  
Indirect Exchange ◽  
Matrix Relation ◽  
Definition Of ◽  
New Formulation ◽  
Total Exchange

A new explicit matrix relation for the calculation of the total exchange areas (TEA) in emitting, absorbing and anisotropically scattering semi-transparent medium bounded by emitting, absorbing and anisotropically reflecting walls has been established. It has been used to directly determine the TEA as a function of radiative properties and geometry of the medium and its boundaries. Computation calls for direct exchange areas (DEA) and indirect exchange areas (IEA). A new definition of these exchange areas reduces their integration order and provides practical energy balance relations for their computation in the case of complex geometry elements. The new formulation is applied in the case of an emitting, absorbing and linearly anisotropic scattering semi-transparent slab bounded by black surfaces. This method is also applicable to nongray medium using the weighted sum of gray gases model.

scholarly journals Tytuł profesora w postępowaniu przed Radą Doskonałości Naukowej

2021 ◽  
pp. 9-63
Author(s):  
Krystyna Wojtczak
Keyword(s):  
Higher Education ◽  
Legal Protection ◽  
Scientific Excellence ◽  
Scientific Disciplines ◽  
The Republic ◽  
Definition Of ◽  
New Formulation ◽  
The Right ◽  
Selection Of

The Act of 20 July 2018 on Higher Education and Science is the eighth Polish normative act of statutory rank since 1920 to deal with matters concerning the title of professor, not counting separate acts and their amendments. It is also the first act based on the regulations in force before 1965 to regulate in a single act matters of higher education and science. Despite their new formulation, not all of the solutions implemented by this Act imply a full withdrawal from the regulations adopted in previous years. What is absolutely new in it, however, is the simplification of the procedure and conditions of the proceedings for conferring the title of professor through: (1) a new definition of fields of science (arts) and scientific disciplines (artistic disciplines) based, following the OECD classification, on the two-tier qualification of sciences (with some exceptions); (2) the constitution of the Council for Scientific Excellence, as a new institution, as of 1 January 2021 exclusively endowed with the right to initiate proceedings for the conferment of the title of professor (including refusal) and the subsequent process, ending with a positive or negative decision of that Council. Other solutions of this law have been subject to broader or narrower changes or have been retained in their current wording. Those of such a nature constitute answers to the following questions: (1) On whom may the title of professor be conferred, and in relation to whom, despite meeting the requirements for it, is this unacceptable, for other statutory reasons?; (2) What requirements does the legislator expect from a candidate for this academic title, and to what extent do the expectations placed on them – outstanding scientific (artistic) achievements – go beyond the framework of the previously binding standards in this regard?; (3) What determines the selection of candidates for reviewers in this procedure, and what is the procedure for selecting them?; (4) What are the conditions for a candidate’s legal protection against negative decisions by the Council for Scientific Excellence, taking into account (5) the conditions for the President of the Republic of Poland’s participation in this procedure, which have remained unchanged since 1990?

scholarly journals Modelo de política óptima de dividendos

2017 ◽  
Vol 10 (20) ◽  
Author(s):  
Jorge Núñez Pérez ◽  
Juan Rositas Martínez ◽  
Manuel Medina Elizondo
Keyword(s):  
Information Content ◽  
Agency Costs ◽  
Dividend Policy ◽  
Binary Logistic Regression ◽  
Building Blocks ◽  
Agency Cost ◽  
General Context ◽  
Binary Logistic Regression Analysis ◽  
Definition Of ◽  
New Formulation

Keywords: agency costs, clienteles of dividends, information content of dividends, irrelevance of dividend policy, transaction costsAbstract. This research addresses one of the fundamental decisions of corporate finance: the dividend policy. It is formulated a model whose building blocks are the theory of irrelevance of the dividends of Modigliani and Miller (as a general context), the signaling model of John Lintner, and the model of Michael S. Rozzef of minimization of agency cost and transaction costs. The construction of the theoretical model of optimal dividend policy proposed here highlights the advantages of the axiomatic definition of the theory of Modigliani and Miller, by its logical contribution, and intends to propose a new formulation with respect to the determination of level of payment of dividends in the corporations. Therefore we relax the assumptions specified by Modigliani and Miller related to liquidity indifference, absence of uncertainty, agency costs and transaction cost, also we explore the possibility of presence of asymmetric information. In such circumstances, for the model exposed here and by means of a binary logistic regression analysis is tested the influence of profits, the information content of dividends, the clientele effect and agency costs to define policy dividends of the corporations in Mexico.Palabras clave: clientelas de dividendos, contenido informativo de los dividendos, costos de agencia, costos de transacción, irrelevancia de la política de dividendosResumen. Esta investigación aborda una de las decisiones fundamentales de las finanzas corporativas: la política de dividendos. Se formula un modelo cuyos bloques de construcción son la teoría de irrelevancia de los dividendos de Modigliani y Miller (como contexto general), el modelo de señalización de John Lintner, y el modelo de Michael S. Rozzef de minimización de costos de agencia y de costos de transacción. La construcción del modelo teórico de política óptima de dividendos aquí propuesto pone de relieve las ventajas de la definición axiomática de la teoría de Modigliani y Miller, en cuanto a contribución lógica, con la intención de acercarnos a una nueva formulación respecto de la determinación del nivel de pago de dividendos en las corporaciones. Para ello se relajan las suposiciones especificadas por Modigliani y Miller en relación a la indiferencia por liquidez, ausencia de incertidumbre, costos de agencia y costos de transacción, también se explora la posibilidad de presencia de información asimétrica. En dichas circunstancias, para el modelo aquí expuesto y mediante un análisis de regresión logística binaria se prueba la influencia de las utilidades, el contenido informativo de los dividendos, el efecto clientela y los costos de agencia para definir la política de dividendos de las corporaciones en México.

scholarly journals Diffusive Bejan number and second law of thermodynamics toward a new dimensionless formulation of fluid dynamics laws

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4005-4022 ◽  
Author(s):  
Michele Trancossi ◽  
Jose Pascoa
Keyword(s):  
Fluid Dynamics ◽  
Entropy Generation ◽  
Fluid Dynamic ◽  
Second Law Of Thermodynamics ◽  
Integral Form ◽  
Second Law ◽  
Bejan Number ◽  
Definition Of ◽  
New Formulation ◽  
Dimensionless Formulation

In a recent paper, Liversage and Trancossi have defined a new formulation of drag as a function of the dimensionless Bejan and Reynolds numbers. Further analysis of this hypothesis has permitted to obtain a new dimensionless formulation of the fundamental equations of fluid dynamics in their integral form. The resulting equations have been deeply discussed for the thermodynamic definition of Bejan number evidencing that the proposed formulation allows solving fluid dynamic problems in terms of entropy generation, allowing an effective optimization of design in terms of the Second law of thermodynamics. Some samples are discussed evidencing how the new formulation can support the generation of an optimized configuration of fluidic devices and that the optimized configurations allow minimizing the entropy generation.

scholarly journals Empirical, Dimensional and Inspectional Analysis in the Design of Bottom Intake Racks

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1035 ◽  
Author(s):  
Juan García ◽  
Luis Castillo ◽  
José Carrillo ◽  
Patricia Haro
Keyword(s):  
Discharge Coefficient ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Design Parameters ◽  
Incoming Flow ◽  
Viscous Forces ◽  
The Mean ◽  
Definition Of ◽  
New Formulation ◽  
Bottom Intake

Flow over bottom racks is highly turbulent, three-dimensional and spatially varied. The design of bottom intake systems has mainly been studied in the laboratory. The comparison of existing experimental studies shows large deviations in the definition of design parameters such as wetted rack length. Each experimental study is limited to a single bar type or to a low range of void ratios, which makes it difficult to generalize the observed data. A combination of empirical, dimensional and inspectional analysis is presented as a useful tool to reduce the number of variables with influence in the design parameters, such as the wetted rack length or the mean discharge coefficient. This work includes a broad experimental campaign in which wetted rack length and mean discharge coefficient are characterized using five different bottom racks with different void ratios (area between bars divided by total area). T-shaped flat and circular bars are considered as well as five different longitudinal slopes. Empirical and inspectional analyses have allowed us to verify, in two different ways, the relation between wetted rack length and incoming flow through potential functions. The influence of the viscous forces has been studied as a function of the incoming flow. Similar results may be obtained when analysing the Froude number at the beginning of the rack, depending on the wetted rack length. A new formulation for calculating the mean discharge coefficient and wetted rack length is proposed.

How Big Is a Lock Number?

2021 ◽  
Vol 66 (1) ◽  
pp. 1-3
Author(s):  
Cory Seidel ◽  
David A. Peters
Keyword(s):  
Main Rotor ◽  
Basic Definition ◽  
Design Variables ◽  
Physical Insight ◽  
Definition Of ◽  
New Formulation ◽  
Insight Into

The traditional Lock number for lifting rotors is recast in terms of a different set of parameters. This new formulation, while not changing the basic definition of the Lock number, gives additional physical insight into the design variables that influence this number. The new formulation enables one to better understand why Lock numbers fall into the range they do. The fundamental basis of the Lock number is studied for 33 rotors, ranging in size from the main rotor of the CH-53E (with seven blades and a diameter of 79 ft) down to the tail rotor of the Robinson R22 Beta (with two blades and a diameter of 3.5 ft).

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