scholarly journals On the Definition of Energy Flux in One-Dimensional Chains of Particles

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1036
Author(s):  
Paolo De Gregorio
Keyword(s):  
Energy Density ◽  
Integral Operator ◽  
Energy Flux ◽  
Ad Hoc ◽  
The Other ◽  
Energy Density Distribution ◽  
One Dimensional ◽  
Integral Quantity ◽  
Definition Of ◽  
Local Quantity

We review two well-known definitions present in the literature, which are used to define the heat or energy flux in one dimensional chains. One definition equates the energy variation per particle to a discretized flux difference, which we here show it also corresponds to the flux of energy in the zero wavenumber limit in Fourier space, concurrently providing a general formula valid for all wavelengths. The other relies somewhat elaborately on a definition of the flux, which is a function of every coordinate in the line. We try to shed further light on their significance by introducing a novel integral operator, acting over movable boundaries represented by the neighboring particles’ positions, or some combinations thereof. By specializing to the case of chains with the particles’ order conserved, we show that the first definition corresponds to applying the differential continuity-equation operator after the application of the integral operator. Conversely, the second definition corresponds to applying the introduced integral operator to the energy flux. It is, therefore, an integral quantity and not a local quantity. More worryingly, it does not satisfy in any obvious way an equation of continuity. We show that in stationary states, the first definition is resilient to several formally legitimate modifications of the (models of) energy density distribution, while the second is not. On the other hand, it seems peculiar that this integral definition appears to capture a transport contribution, which may be called of convective nature, which is altogether missed by the former definition. In an attempt to connect the dots, we propose that the locally integrated flux divided by the inter-particle distance is a good measure of the energy flux. We show that the proposition can be explicitly constructed analytically by an ad hoc modification of the chosen model for the energy density.

Myth and Poetry in Macondo

2021 ◽  
pp. 322-340
Author(s):  
Mercedes López-Baralt
Keyword(s):  
Nobel Prize ◽  
Historical Perspective ◽  
Tree Of Life ◽  
The Other ◽  
The Novel ◽  
Absolute Truth ◽  
One Dimensional ◽  
Cyclical Time ◽  
Definition Of ◽  
Acceptance Speech

One Hundred Years of Solitude has frequently been approached from a historical perspective, focusing on the colonial imprint in Latin America’s destiny. Yet in his Nobel Prize acceptance speech, García Márquez made it clear that he wished to be remembered for the poetry that permeates his writing. This article is inspired by this assertion, as well as by a quote from Ernesto Sabato, who claims that for philosophers and artists, myth and poetry are keys to access the Absolute: truth, beauty, and perfection. Taking into account the few previous attempts to pursue these motifs in the novel, the article undertakes a search of the traces of both myth and poetry in García Márquez’s opera magna. The faces of myth are many: Oedipus, prophecies, magic, utopia, the mandala of the tree of life, cyclical time, alchemy, one-dimensional characters (actants), genesis, and apocalypse. On the other hand, poems and metaphors are ever present in the novel. This search led to a new reading of One Hundred Years of Solitude, discovering García Márquez’ celebration of ambiguity. For the novel’s conclusion moves the reader to two opposing interpretations: apocalypse (the destruction of Macondo and the solitary Buendía dynasty) and hope (solidarity in a new mankind). The possibility of clashing readings confirms Italo Calvino’s definition of a classic as a book that never finishes saying what it has to say.

Energy Counterexamples in Two Weight Calderón–Zygmund Theory

2019 ◽  
Author(s):  
Eric T Sawyer ◽  
Chun-Yen Shen ◽  
Ignacio Uriarte-Tuero
Keyword(s):  
Integral Operator ◽  
Singular Integral Operator ◽  
Singular Integral ◽  
Hilbert Transform ◽  
The Other ◽  
Energy Conditions ◽  
Convolution Kernel ◽  
One Dimensional ◽  
T1 Theorem ◽  
The Hilbert Transform

Abstract We show that the energy conditions are not necessary for boundedness of Riesz transforms in dimension $n\geq 2$. In dimension $n=1$, we construct an elliptic singular integral operator $H_{\flat } $ for which the energy conditions are not necessary for boundedness of $H_{\flat }$. The convolution kernel $K_{\flat }\left ( x\right ) $ of the operator $H_{\flat }$ is a smooth flattened version of the Hilbert transform kernel $K\left ( x\right ) =\frac{1}{x}$ that satisfies ellipticity $ \vert K_{\flat }\left ( x\right ) \vert \gtrsim \frac{1}{\left \vert x\right \vert }$, but not gradient ellipticity $ \vert K_{\flat }^{\prime }\left ( x\right ) \vert \gtrsim \frac{1}{ \vert x \vert ^{2}}$. Indeed the kernel has flat spots where $K_{\flat }^{\prime }\left ( x\right ) =0$ on a family of intervals, but $K_{\flat }^{\prime }\left ( x\right ) $ is otherwise negative on $\mathbb{R}\setminus \left \{ 0\right \} $. On the other hand, if a one-dimensional kernel $K\left ( x,y\right ) $ is both elliptic and gradient elliptic, then the energy conditions are necessary, and so by our theorem in [30], the $T1$ theorem holds for such kernels on the line. This paper includes results from arXiv:16079.06071v3 and arXiv:1801.03706v2.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

scholarly journals Language Family Engineering with Product Lines of Multi-level Models

2021 ◽  
Author(s):  
Juan de Lara ◽  
Esther Guerra
Keyword(s):  
Software Engineering ◽  
Arbitrary Number ◽  
Formal Theory ◽  
The Other ◽  
Language Family ◽  
Top Down ◽  
Product Lines ◽  
Modelling Languages ◽  
Multi Level ◽  
Definition Of

AbstractModelling is an essential activity in software engineering. It typically involves two meta-levels: one includes meta-models that describe modelling languages, and the other contains models built by instantiating those meta-models. Multi-level modelling generalizes this approach by allowing models to span an arbitrary number of meta-levels. A scenario that profits from multi-level modelling is the definition of language families that can be specialized (e.g., for different domains) by successive refinements at subsequent meta-levels, hence promoting language reuse. This enables an open set of variability options given by all possible specializations of the language family. However, multi-level modelling lacks the ability to express closed variability regarding the availability of language primitives or the possibility to opt between alternative primitive realizations. This limits the reuse opportunities of a language family. To improve this situation, we propose a novel combination of product lines with multi-level modelling to cover both open and closed variability. Our proposal is backed by a formal theory that guarantees correctness, enables top-down and bottom-up language variability design, and is implemented atop the MetaDepth multi-level modelling tool.

scholarly journals Burnout in Professional Caregivers and Quality of Life in Institutionalized Center Residents

2013 ◽  
Vol 4 (1) ◽  
pp. 41-53
Author(s):  
Juan P. Martínez ◽  
Inmaculada Méndez ◽  
Esther Secanilla ◽  
Ana Benavente ◽  
Julia García Sevilla
Keyword(s):  
Quality Of Life ◽  
Ad Hoc ◽  
Maslach Burnout Inventory ◽  
The Other ◽  
People With Dementia ◽  
Professional Caregiver ◽  
The One ◽  
Shed Light ◽  
Professional Accomplishment

Starting from previous studies in professional caregivers of people with dementia and other diseases in institutionalized centers of different regions, the aim of this study was to compare burnout levels that workers present depending on the center, to create a caregiver profile with high professional accomplishment and to describe the quality of life that residents perceive Murcia and Barcelona. The instruments used were the Maslach Burnout Inventory (MBI), the Professional Caregiver Survey developed ad hoc and the Brief Questionnaire of Quality of Life (CUBRECAVI in Spanish) on residents. The results show, on the one hand, that levels of professional accomplishment may be paradoxically higher in the case of catastrophe and, on the other hand, the 98.2% of users are satisfied with the residence in which is located and 81.8% with the manner in which occupy the time. The conclusions that are extrapolated from the study shed light on the current situation of workers and residents and the influence that an earthquake can have on them.

Asymptotic derivation of a refined equation for an elastic beam resting on a Winkler foundation

2021 ◽  
pp. 108128652110238
Author(s):  
Barış Erbaş ◽  
Julius Kaplunov ◽  
Isaac Elishakoff
Keyword(s):  
Ad Hoc ◽  
Moving Load ◽  
Low Frequency ◽  
Elastic Beam ◽  
Winkler Foundation ◽  
One Dimensional ◽  
Beam Equations ◽  
Dimensional Equation ◽  
Phase And Group Velocities ◽  
Group Velocities

A two-dimensional mixed problem for a thin elastic strip resting on a Winkler foundation is considered within the framework of plane stress setup. The relative stiffness of the foundation is supposed to be small to ensure low-frequency vibrations. Asymptotic analysis at a higher order results in a one-dimensional equation of bending motion refining numerous ad hoc developments starting from Timoshenko-type beam equations. Two-term expansions through the foundation stiffness are presented for phase and group velocities, as well as for the critical velocity of a moving load. In addition, the formula for the longitudinal displacements of the beam due to its transverse compression is derived.

scholarly journals Assessing a Linear Nanosystem's Limiting Reliability from its Components

2008 ◽  
Vol 45 (03) ◽  
pp. 879-887 ◽  
Author(s):  
Nader Ebrahimi
Keyword(s):  
Present State ◽  
Size Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Present Moment ◽  
One Dimensional ◽  
The One ◽  
Fixed Moment ◽  
Nanosized Systems

Nanosystems are devices that are in the size range of a billionth of a meter (1 x 10-9) and therefore are built necessarily from individual atoms. The one-dimensional nanosystems or linear nanosystems cover all the nanosized systems which possess one dimension that exceeds the other two dimensions, i.e. extension over one dimension is predominant over the other two dimensions. Here only two of the dimensions have to be on the nanoscale (less than 100 nanometers). In this paper we consider the structural relationship between a linear nanosystem and its atoms acting as components of the nanosystem. Using such information, we then assess the nanosystem's limiting reliability which is, of course, probabilistic in nature. We consider the linear nanosystem at a fixed moment of time, say the present moment, and we assume that the present state of the linear nanosystem depends only on the present states of its atoms.

Identity, Community and Belonging in gcc States

2018 ◽  
Vol 6 (4) ◽  
pp. 401-428
Author(s):  
Miriam R. Lowi
Keyword(s):  
Religious Affiliation ◽  
Protective Role ◽  
The Other ◽  
National Project ◽  
Scholarly Literature ◽  
National Community ◽  
The Difference ◽  
Definition Of

Studies of identity and belonging in Gulf monarchies tend to privilege tribal or religious affiliation, if not the protective role of the ruler as paterfamilias. I focus instead on the ubiquitous foreigner and explore ways in which s/he contributes to the definition of national community in contemporary gcc states. Building upon and moving beyond the scholarly literature on imported labor in the Gulf, I suggest that the different ‘categories’ of foreigners impact identity and the consolidation of a community of privilege, in keeping with the national project of ruling families. Furthermore, I argue that the ‘European,’ the non-gcc Arab, and the predominantly Asian (and increasingly African) laborer play similar, but also distinct roles in the delineation of national community: while they are differentially incorporated in ways that protect the ‘nation’ and appease the citizen-subject, varying degrees of marginality reflect Gulf society’s perceptions or aspirations of the difference between itself and ‘the other(s).’

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