scholarly journals Definition of Alloy Substitute Thermal Capacity Using the Simple Macrosegregation Models

2012 ◽  
Vol 12 (4) ◽  
pp. 113-116 ◽  
Author(s):  
B. Mochnacki
Keyword(s):  
Solid State ◽  
Mathematical Description ◽  
Energy Equation ◽  
Analytical Form ◽  
Thermal Capacity ◽  
Thermal Processes ◽  
Volumetric Fraction ◽  
Macro Scale ◽  
The One ◽  
Definition Of

Abstract Mathematical description of alloys solidification in a macro scale can be formulated using the one domain method (fixed domain approach). The energy equation corresponding to this model contains the parameter called a substitute thermal capacity (STC). The analytical form of STC results from the assumption concerning the course of the function fS = fS (T) describing the changes of solid state volumetric fraction and the temperature at the point considered. Between border temperatures TS , TL the function fS changes from 1 to 0. In this paper the volumetric fraction fS (more precisely fL = 1- fS ) is found using the simple models of macrosegregation (the lever arm rule, the Scheil model). In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy.

Numerical Modeling of Solidification Substitute – Thermal Capacity of Binary Alloy

2014 ◽  
Vol 354 ◽  
pp. 33-40
Author(s):  
Bohdan Mochnacki ◽  
R. Szopa
Keyword(s):  
Numerical Modeling ◽  
Solid State ◽  
Mathematical Description ◽  
Energy Equation ◽  
Analytical Form ◽  
Thermal Capacity ◽  
Thermal Processes ◽  
Volumetric Fraction ◽  
Macro Scale ◽  
The One

Mathematical description of alloys solidification on the macro scale can be formulated using the one domain method (fixed domain approach). The energy equation corresponding to this model contains the parameter called the substitute thermal capacity (STC). The analytical form of STC results from the assumption concerning the course of the functionfS=fS(T) describing the changes of solid state volumetric fraction and the temperature at the point considered. Between border temperaturesTS,TLthe functionfSchanges from 1 to 0. In this paper the volumetric fractionfS(more preciselyfL= 1-fS) is found using the simple models of macrosegregation (the lever arm rule, the Scheil model). In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy.

Numerical Modeling of Casting Solidification Using Generalized Finite Difference Method

2010 ◽  
Vol 638-642 ◽  
pp. 2676-2681 ◽  
Author(s):  
Bohdan Mochnacki ◽  
Ewa Majchrzak
Keyword(s):  
Finite Difference ◽  
Finite Difference Method ◽  
Difference Method ◽  
Energy Equation ◽  
Solidification Process ◽  
Temperature Gradients ◽  
Thermal Processes ◽  
Heating Rates ◽  
Collocation Points ◽  
The One

The system casting-mould is considered. The thermal processes proceeding in a casting sub-domain are described using the one domain approach. The model of solidification process is supplemented by the energy equation concerning the mould sub-domain, the continuity conditions given on the contact surface between casting and mould, boundary conditions on the outer surface of the system and the initial ones. To solve the problem the generalized variant of finite difference method (GFDM) is used. Temporary and local values of temperature can be found at the optional set of collocation points from the domain considered. This essential advantage of GFDM allows to locate and thicken nodes at the regions for which the temperature gradients and cooling (heating) rates are considerable. In the final part of the paper, the example of numerical simulation is shown.

scholarly journals Numerical Model Of Binary Alloys Solidification Basing On The One Domain Approach And The Simple Macrosegregation Models

2015 ◽  
Vol 60 (3) ◽  
pp. 2431-2435 ◽  
Author(s):  
E. Majchrzak ◽  
B. Mochnacki ◽  
J. Mendakiewicz
Keyword(s):  
Mathematical Model ◽  
Numerical Model ◽  
Finite Difference Method ◽  
Numerical Solutions ◽  
Thermal Capacity ◽  
Thermal Processes ◽  
Domain Method ◽  
The Finite Difference Method ◽  
The One ◽  
The Mathematical Model

AbstractIn the paper the thermal processes proceeding in the domain of solidifying binary alloy are considered. The mathematical model of solidification and cooling processes bases on the one domain method (or fixed domain method). In such a model the parameter called a substitute thermal capacity (STC) appears. At the stage of STC construction the macrosegregation process described by the lever arm rule or the Scheil model is taken into account. In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy. In the final part the examples of numerical solutions basing on the finite difference method are presented.

Understanding functional illiteracy from a policy, adult education, and cognition point of view: Towards a joint referent framework

2019 ◽  
Vol 30 (2) ◽  
pp. 109-122
Author(s):  
Aleksandar Bulajić ◽  
Miomir Despotović ◽  
Thomas Lachmann
Keyword(s):  
Adult Education ◽  
Operational Definition ◽  
Literacy Skills ◽  
Point Of View ◽  
Industrialized Countries ◽  
Functional Illiteracy ◽  
Scale Levels ◽  
Components Of Reading ◽  
The One ◽  
Definition Of

Abstract. The article discusses the emergence of a functional literacy construct and the rediscovery of illiteracy in industrialized countries during the second half of the 20th century. It offers a short explanation of how the construct evolved over time. In addition, it explores how functional (il)literacy is conceived differently by research discourses of cognitive and neural studies, on the one hand, and by prescriptive and normative international policy documents and adult education, on the other hand. Furthermore, it analyses how literacy skills surveys such as the Level One Study (leo.) or the PIAAC may help to bridge the gap between cognitive and more practical and educational approaches to literacy, the goal being to place the functional illiteracy (FI) construct within its existing scale levels. It also sheds more light on the way in which FI can be perceived in terms of different cognitive processes and underlying components of reading. By building on the previous work of other authors and previous definitions, the article brings together different views of FI and offers a perspective for a needed operational definition of the concept, which would be an appropriate reference point for future educational, political, and scientific utilization.

About definition of the local entropy rate of production in experiment of pulse electric heating

2020 ◽  
pp. 29-34
Author(s):  
Alexandr V. Kostanovskiy ◽  
Margarita E. Kostanovskaya
Keyword(s):  
Thermal Diffusivity ◽  
Electric Heating ◽  
Thermal Capacity ◽  
Entropy Rate ◽  
Initial Time ◽  
Local Entropy ◽  
Linear Mode ◽  
Electric Capacity ◽  
Definition Of ◽  
Pulse Electric

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.

Democracy and Political Culture

2019 ◽  
Author(s):  
Ross McKibbin
Keyword(s):  
Political Culture ◽  
Case Studies ◽  
Social System ◽  
Political System ◽  
Democratic Politics ◽  
Social Structures ◽  
The Political ◽  
The Subject ◽  
The One ◽  
Definition Of

This book is an examination of Britain as a democratic society; what it means to describe it as such; and how we can attempt such an examination. The book does this via a number of ‘case-studies’ which approach the subject in different ways: J.M. Keynes and his analysis of British social structures; the political career of Harold Nicolson and his understanding of democratic politics; the novels of A.J. Cronin, especially The Citadel, and what they tell us about the definition of democracy in the interwar years. The book also investigates the evolution of the British party political system until the present day and attempts to suggest why it has become so apparently unstable. There are also two chapters on sport as representative of the British social system as a whole as well as the ways in which the British influenced the sporting systems of other countries. The book has a marked comparative theme, including one chapter which compares British and Australian political cultures and which shows British democracy in a somewhat different light from the one usually shone on it. The concluding chapter brings together the overall argument.

An LQ Approach to Active Control of Vibrations in Helicopters

1996 ◽  
Vol 118 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Sergio Bittanti ◽  
Fabrizio Lorito ◽  
Silvia Strada
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Linear Quadratic ◽  
Control Effort ◽  
Vibration Effect ◽  
Suitable Definition ◽  
Lq Optimal Control ◽  
The One ◽  
Definition Of ◽  
And Control

In this paper, Linear Quadratic (LQ) optimal control concepts are applied for the active control of vibrations in helicopters. The study is based on an identified dynamic model of the rotor. The vibration effect is captured by suitably augmenting the state vector of the rotor model. Then, Kalman filtering concepts can be used to obtain a real-time estimate of the vibration, which is then fed back to form a suitable compensation signal. This design rationale is derived here starting from a rigorous problem position in an optimal control context. Among other things, this calls for a suitable definition of the performance index, of nonstandard type. The application of these ideas to a test helicopter, by means of computer simulations, shows good performances both in terms of disturbance rejection effectiveness and control effort limitation. The performance of the obtained controller is compared with the one achievable by the so called Higher Harmonic Control (HHC) approach, well known within the helicopter community.

scholarly journals Beyond Classical Definition: The Non-definition of Gamification

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Mario S. Staller ◽  
Swen Koerner
Keyword(s):  
Empirical Investigation ◽  
Working Life ◽  
Pedagogical Practice ◽  
Police Recruits ◽  
Design Elements ◽  
The Subject ◽  
Anchor Points ◽  
The One ◽  
Definition Of ◽  
Game Elements

AbstractGamification is regularly defined as the use of game elements in non-gaming contexts. However, discussions in the context of the pedagogical value of gamification suggest controversies on various levels. While on the one hand, the potential is seen in the design of joyful learning environments, critics point out the pedagogical dangers or the problems related to optimizing working life. It becomes apparent that the assumptions guiding action on the subject matter of gamification in educational contexts differ, which leads to different derivations for pedagogical practice—but also allows for different perspectives on initially controversial positions. Being aware of these assumptions is the claim of a reflexive pedagogy. With regard to the pedagogical use of gamifying elements and their empirical investigation, there are three main anchor points to consider from a reflexive stance: (a) the high context-specificity of the teaching undertaken and (b) the (non-)visibility of the design elements and (c) the (non-)acceptance of the gamified elements by the students. We start by providing a discussion of the definitional discourse on what is understood as gamification leading to our argument for a non-definition of gamification. We describe the potential of this non-definition of gamification and exemplify its use in a gamified concept of teaching police recruits professional reflexivity. The concept features the narrative of a potential crime that has been undertaken and that students decide for themselves if they want to engage with it.

scholarly journals The contribution of resident physicians to hospital productivity

2021 ◽  
Author(s):  
Maria J. Perez-Villadóniga ◽  
Ana Rodriguez-Alvarez ◽  
David Roibas
Keyword(s):  
Production Functions ◽  
Weighted Sum ◽  
Main Hypothesis ◽  
Resident Physicians ◽  
Suitable Parameter ◽  
Functional Forms ◽  
The One ◽  
Definition Of ◽  
Hospital Productivity ◽  
Natural Hypothesis

AbstractResident physicians play a double role in hospital activity. They participate in medical practices and thus, on the one hand, they should be considered as an input. Also, they are medical staff in training and, on the other hand, must be considered as an output. The net effect on hospital activities should therefore be empirically determined. Additionally, when considering their role as active physicians, a natural hypothesis is that resident physicians are not more productive than senior ones. This is a property that standard logarithmic production functions (including Cobb–Douglas and Translog functional forms) cannot verify for the whole technology set. Our main contribution is the development of a Translog modification, which implies the definition of the input “doctors” as a weighted sum of senior and resident physicians, where the weights are estimated from the empirical application. This modification of the standard Translog is able, under suitable parameter restrictions, to verify our main hypothesis across the whole technology set while determining if the net effect of resident physicians in hospitals’ production should be associated to an output or to an input. We estimate the resulting output distance function frontier with a sample of Spanish hospitals. Our findings show that the overall contribution of resident physicians to hospitals’ production allows considering them as an input in most cases. In particular, their average productivity is around 37% of that corresponding to senior physicians.

Ex Meritis Praevisis: Predestination, Grace, and Free Will in intra-Jesuit Controversies (1587-1613)

2020 ◽  
Vol 7 (1) ◽  
pp. 111-150
Author(s):  
Eleonora Rai
Keyword(s):  
Free Will ◽  
Society Of Jesus ◽  
Modern Age ◽  
Sovereign Authority ◽  
Theological Debate ◽  
The One ◽  
Definition Of ◽  
The Relationship ◽  
God’S Foreknowledge ◽  
Catholic Theological

AbstractThis article retraces the intra-Jesuit theological debates on the theology of salvation, including the relationship between the elements of predestination, God’s foreknowledge, Grace, and free will, in the delicate passage between the sixteenth and the seventeenth centuries, and within the debates on Augustine’s theological legacy. Specifically, it explores the Flemish Jesuit Leonard Lessius’ theology and the discussions raised by it within the Society of Jesus, in order to show how soteriology has been central in the process of self-definition of the Jesuit identity in the Early Modern Age. This is particularly clear from the internal debates developed between Lessius, on the one hand, and General Claudio Acquaviva and curial theologian Roberto Bellarmino, on the other hand. Not only does the article investigate little known aspects of intra-Catholic theological debate in the post Tridentine period, but it also shows how deep pastoral and moral concerns strongly contributed to the rise of Lessius’ open-minded theology of salvation, which seemed to deprive God’s sovereign authority in favour of humankind’s free will, and human agency in the process of salvation.

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