Torsional magnetic reconnection: The effects of localizing the non-ideal (ηJ) term

2011 ◽  
Vol 77 (6) ◽  
pp. 843-855 ◽  
Author(s):  
PETER F. WYPER ◽  
REKHA JAIN
Keyword(s):  
Magnetic Reconnection ◽  
Natural Extension ◽  
Flow Characteristics ◽  
Two Dimensions ◽  
Point Of View ◽  
Three Dimensions ◽  
Current Profile ◽  
Change In Practice ◽  
Kinematic Models

AbstractMagnetic reconnection in three dimensions (3D) is a natural extension from X-point reconnection in two dimensions. Of central importance in the 3D process is a localized non-ideal region within which the plasma and magnetic field decouple allowing for field line connectivity change. In practice, localized current structures provide this localization; however, mathematically a similar effect can be achieved with the localization of plasma resistivity instead. Physically though, such approaches are unrealistic, as anomalous resistivity requires very localized currents. Therefore, we wish to know how much information is lost in localizing η instead of current? In this work we develop kinematic models for torsional spine and fan reconnection using both localized η and localized current and compare the non-ideal flows predicted by each. We find that the flow characteristics are dictated almost exclusively by the form taken for the current profile with η acting only to scale the flow. We do, however, note that the reconnection mechanism is the same in each case. Therefore, from an understanding point of view, localized η models are still important first steps into exploring the role of non-ideal effects.

scholarly journals The Role of Scientific Research in Local Community Service from the Perspective of Faculty Members of some Palestinian Universities

2020 ◽  
Vol 13 (44) ◽  
pp. 1-27
Author(s):  
أ.د. زياد بركات
Keyword(s):  
Community Service ◽  
Applied Research ◽  
Local Community ◽  
Scientific Research ◽  
Two Dimensions ◽  
Faculty Members ◽  
Three Dimensions ◽  
Awareness Raising ◽  
Palestinian Universities

The present study aimed at investigating the role of scientific research in the development of the local community from the point of view of the faculty members in the Palestinian Universities. To achieve this objective, a convenient sample of (244) faculty members from the universities of northern Palestine: Al-Quds Open University (Tulkarm), An-Najah National (Nablus), Technical Palestine - Khadouri (Tulkarem), and Arab American (Jenin). The results of the study showed that the participants' assessment of the importance of the role of scientific research in community development was medium in the overall instrument and two dimensions: applied research and scientific consultancy, but their assessment of awareness-raising was high. On the other hand, the results showed that there were statistically significant differences in the level of the role of practical research in the development of the community attributed to the gender variable in favor of males on the overall instrument and three dimensions, while there were no statistically significant differences in the level of participants' assessment attributed to the variable of specialization. The differences were in favor of the disciplines of educational sciences and applied sciences. There were also statistically significant differences in the level of their assessment attributed to the qualification variable on the overall instrument and the three dimensions in favor of PhD holders.Keywords: scientific research, community service, awareness-raising, applied research, scientific consultancy.

scholarly journals 3D Magnetic Reconnection

2010 ◽  
Vol 6 (S271) ◽  
pp. 227-238 ◽  
Author(s):  
Clare E. Parnell ◽  
Rhona C. Maclean ◽  
Andrew L. Haynes ◽  
Klaus Galsgaard
Keyword(s):  
Magnetic Reconnection ◽  
Energy State ◽  
Single Point ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Wide Range ◽  
Field Lines ◽  
Magnetohydrodynamic Models ◽  
The Magnetic Field

AbstractMagnetic reconnection is an important process that is prevalent in a wide range of astrophysical bodies. It is the mechanism that permits magnetic fields to relax to a lower energy state through the global restructuring of the magnetic field and is thus associated with a range of dynamic phenomena such as solar flares and CMEs. The characteristics of three-dimensional reconnection are reviewed revealing how much more diverse it is than reconnection in two dimensions. For instance, three-dimensional reconnection can occur both in the vicinity of null points, as well as in the absence of them. It occurs continuously and continually throughout a diffusion volume, as opposed to at a single point, as it does in two dimensions. This means that in three-dimensions field lines do not reconnect in pairs of lines making the visualisation and interpretation of three-dimensional reconnection difficult.By considering particular numerical 3D magnetohydrodynamic models of reconnection, we consider how magnetic reconnection can lead to complex magnetic topologies and current sheet formation. Indeed, it has been found that even simple interactions, such as the emergence of a flux tube, can naturally give rise to ‘turbulent-like’ reconnection regions.

Stereotyping Older Workers and Retirement: The Managers' Point of View

2005 ◽  
Vol 24 (4) ◽  
pp. 353-366 ◽  
Author(s):  
Kène Henkens
Keyword(s):  
Older Workers ◽  
Organizational Factors ◽  
Two Dimensions ◽  
Point Of View ◽  
The Other ◽  
Three Dimensions ◽  
Older Employees ◽  
Psychological Mechanisms ◽  
Frequent Contact ◽  
Components Analysis

ABSTRACTThis article presents the results of a study into stereotyping by managers of their older workers and the influence of these stereotypes on the inclination of managers to keep their older workers in employment. The data for the study were gathered among 796 managers. Through principal components analysis, 15 opinions about older workers were reduced to three dimensions of stereotypes. The first dimension deals with the productivity of older staff; the other two dimensions have to do with their reliability and their adaptability. These stereotypical ideas about older workers influence managers' attitudes toward the retirement of their employees. The analyses show that, besides organizational factors, psychological mechanisms also explain why people view older workers through stereotypes. Managers who are older and in more frequent contact with older employees tend to hold more positive views.

scholarly journals Open innovation in specialized SMEs: the case of supercars

2017 ◽  
Vol 23 (6) ◽  
pp. 1167-1195 ◽  
Author(s):  
Andres Ramirez-Portilla ◽  
Enrico Cagno ◽  
Terrence E. Brown
Keyword(s):  
Open Innovation ◽  
Structural Equation ◽  
Social Performance ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Equation Modeling ◽  
Content Type ◽  
Firm Innovativeness ◽  
And Performance

Purpose The purpose of this paper is to explore the influence that adopting open innovation (OI) has on the innovativeness and performance of specialized small and medium-sized enterprises (SMEs). This paper also examines the adoption of OI within a firm’s practices and models, and within the three dimensions of firm sustainability. Design/methodology/approach Survey data from 48 specialized SMEs manufacturing supercars were analyzed using partial least squares structural equation modeling. SmartPLS software was used to conduct a path analysis and test the proposed framework. Findings The findings suggest that high adoption of OI models tends to increase firm innovativeness. Similarly, the adoption of OI practices has a positive effect on innovativeness but to a lesser extent than OI models. The moderation results of innovativeness further show that OI models and practices can benefit the performance of SMEs. Specifically, two dimensions of performance – environmental and social performance – were found to be greatly influenced by OI. Research limitations/implications Due to parsimony in the investigated model, this study only focuses on OI adoption as practices and models without considering its drivers or other contingency factors. Practical implications This paper could help practitioners in SMEs better understand the benefits of adopting OI to be more innovative but also more sustainable. Originality/value This study contributes to the literature on the role of OI practices and models regarding the dimensions of firm sustainability performance by being the first paper to investigate this relationship in the context of small and medium manufacturers of supercars.

scholarly journals CONFORMAL MODELS OF MAGNETOHYDRODYNAMIC TURBULENCE

1996 ◽  
Vol 11 (29) ◽  
pp. 5261-5277 ◽  
Author(s):  
OMDUTH COCEAL ◽  
STEVEN THOMAS
Keyword(s):  
Three Dimensional ◽  
Approximate Solutions ◽  
Velocity Fields ◽  
Point Of View ◽  
Three Dimensions ◽  
Finite Conductivity ◽  
Magnetohydrodynamic Turbulence ◽  
Infinite Conductivity ◽  
Conformal Models

Following the previous work of Ferretti and Yang on the role of magnetic fields in the theory of conformal turbulence, we show that nonunitary minimal model solutions to two-dimensional magnetohydrodynamics (MHD) obtained by dimensional reduction from three dimensions exist under different (and more restrictive) conditions. From a three-dimensional point of view, these conditions are equivalent to perpendicular flow, in which the magnetic and velocity fields are orthogonal. We extend the analysis to the finite conductivity case and present some approximate solutions, whose connection with the exact ones of the infinite conductivity case is also discussed.

On Misoriented Letters

Perception ◽  
1984 ◽  
Vol 13 (6) ◽  
pp. 687-694 ◽  
Author(s):  
Paola Bressan ◽  
Giovanni B Vicario
Keyword(s):  
Simple Model ◽  
Vertical Axis ◽  
Picture Plane ◽  
Two Dimensions ◽  
Point Of View ◽  
Horizontal Axis ◽  
Three Dimensions

An experiment is reported in which subjects were presented with misoriented letters and asked to identify the transformations to which normal letters had been subjected to produce the misorientation. When two or more transformations were equally justifiable from the geometrical point of view, they did not have necessarily the same relevance from the perceptual standpoint. For instance, it was easier for the subjects to see an upside-down letter R as the outcome of two reflections (one about the horizontal axis and one about the vertical axis) rather than of a 180° rotation in the picture plane. Contrary to expectation, for the same final result a reflection—a movement in three dimensions—was preferred to a rotation—a movement in two dimensions—and two reflections were preferred to a single rotation. To explain the distribution of the responses, a hypothesis on the ‘mode of appearance’ of equivocally oriented objects is presented. This postulates that the directional axes assigned to the objects tend to remain in correspondence with those of the environment. Moreover, the polarization of the up–down axis tends to be preserved, while that of the left-right axis does not. Implications of this simple model for the perception of misorientations are discussed.

Concentrated Force Near a Smooth Circular Inclusion

1966 ◽  
Vol 33 (4) ◽  
pp. 871-876 ◽  
Author(s):  
J. Dundurs ◽  
K. Fukui ◽  
T. Fukui
Keyword(s):  
Circular Inclusion ◽  
Two Dimensions ◽  
Point Of View ◽  
Three Dimensions ◽  
Infinite Matrix ◽  
Elementary Functions ◽  
Concentrated Force ◽  
Curved Boundary ◽  
Smooth Interface ◽  
Interesting Behavior

A concentrated force applied to an infinite matrix near a smooth circular inclusion is discussed. The smooth interface is defined as one that allows slip, but does not transmit shearing tractions. The solution is partially in terms of series, but for certain combinations of materials the series sum to elementary functions. The solution which is of significance for applications in micromechanics exhibits interesting behavior also from the point of view of classical elastostatics. When the force is allowed to approach the interface, the singularity for the force shows dependence on the curvature of the interface. In this respect the smooth interface between two materials in two dimensions resembles a curved boundary in three dimensions.

scholarly journals L’accompagnement selon une démarche réflexive sur-dans-pour la pratique tel que vécu par trois types d’acteurs

2021 ◽  
Vol 55 (2) ◽  
pp. 285-304
Author(s):  
Patricia Marie Anne Houde ◽  
Suzanne Guillemette
Keyword(s):  
Point Of View ◽  
Language Teachers ◽  
Three Dimensions ◽  
Research Approach ◽  
Doctoral Candidate ◽  
Action Research Approach ◽  
Second Language Teachers ◽  
Research Director ◽  
And Training

Collective accompaniment, as per the reflexivity approach on-in-for practice, requires the adoption of different postures, whether one is placed in the role of the accompanying or accompanied person. This article presents the lived experiences of an accompaniment process fostering research and training within an individual and collective reflexivity approach. Three types of actors are interrelated: an accompanying research director, an accompanied and accompanying doctoral candidate, and accompanied and accompanying English as a second language teachers. Advocating for an action-research approach using the first-person point of view (“I”), each actor was invited to reflect on their practice from an on-in-for perspective. The discussion presents three dimensions: the role of ethical rules, the art of questioning, and the interdependence between involved actors.

scholarly journals Three-dimensional magnetic reconnection in astrophysical plasmas

2021 ◽  
Vol 477 (2249) ◽  
Author(s):  
Ting Li ◽  
Eric Priest ◽  
Ruilong Guo
Keyword(s):  
Magnetic Reconnection ◽  
Solar Flares ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Particle Energy ◽  
Two Dimensions ◽  
Three Dimensions ◽  
New Paradigm ◽  
Astrophysical Plasmas ◽  
Fundamental Process

Magnetic reconnection is a fundamental process in laboratory, magnetospheric, solar and astrophysical plasmas, whereby magnetic energy is converted into heat, bulk kinetic energy and fast particle energy. Its nature in two dimensions is much better understood than that in three dimensions, where its character is completely different and has many diverse aspects that are currently being explored. Here, we focus on the magnetohydrodynamics of three-dimensional reconnection in the plasma environment of the Solar System, especially solar flares. The theory of reconnection at null points, separators and quasi-separators is described, together with accounts of numerical simulations and observations of these three types of reconnection. The distinction between separator and quasi-separator reconnection is a theoretical one that is unimportant for the observations of energy release. A new paradigm for solar flares, in which three-dimensional reconnection plays a central role, is proposed.

scholarly journals Multidimensional research on university engagement using a mixed method approach

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Helena Benito Mundet ◽  
Esther Llop Escorihuela ◽  
Marta Verdaguer Planas ◽  
Joaquim Comas Matas ◽  
Ariadna Lleonart Sitjar ◽  
...  
Keyword(s):  
Two Dimensions ◽  
Point Of View ◽  
Three Dimensions ◽  
Theoretical Point ◽  
Social Commitment ◽  
Cognition And Emotion ◽  
Nominal Groups ◽  
Valid Instrument ◽  
The One ◽  
Definition Of

The commitment or academic implication (engagement) of universitystudents has become a fundamental element for their welfare and academicperformance and, furthermore, it is also related to their professional futureand social commitment. For this reason, the definition of the concept and theprovision of assessment strategies and tools are essential to know the learningexperiences that lead to enhancing the academic involvement of the students.To develop our research, we have used a mixed quantitative and qualitativemethodology: exploratory and confirmatory factor analysis on the one hand,and discussion groups using the nominal groups technique on the other hand.We have set three different objectives: first, to delve into the multidimensionalmodel of the construct; second, to validate a questionnaire that allows forevaluation of the students’ perception of the learning methodologies used inthe classroom; and third, to check the manageability of the nominal groupsas a qualitative method of analysis. The results demonstrate that our newproposal provides a statistically valid instrument aimed at determining theperceptions of own engagement and an effective, efficient and motivatingqualitative method for students. However, regarding the multidimensionalityof the construct, contrary to the more accepted theoretical point of view thatconsiders three dimensions of engagement (behaviour, cognition and emotion),our results only reveal two dimensions (cognitive-emotional and behavioural).In the discussion and comments section we give possible explanations for thiscontradiction.

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