Le bois comme composant d'écosystème

1991 ◽  
Vol 56 ◽  
Author(s):  
H. Beeckman ◽  
K. Vander Mijnsbrugge
Keyword(s):  
Large Scale ◽  
Ecological Study ◽  
Second Law Of Thermodynamics ◽  
Small Scale ◽  
Second Law ◽  
Heat Accumulation ◽  
Positive Effects ◽  
The Earth ◽  
Ecosystem Component

Wood as an ecosystem component - An  ecological study of wood as a material has to define two ecosystems of a  different level of integration.     The small-scale ecosystems are the dwelling houses, where a considerable  amount of wood is used for several purposes. Positive effects of wood on the  health of the inhabitants are reported. These effects establish the  significance of the typical association wood-mankind.     The large-scale ecosystem is the global ecosystem of the earth. Ecological  diagnostics on this level have to take into account the Second Law of  Thermodynamics. Forestry and intelligent use of wood are able to slow down  entropy and heat accumulation in the atmosphere.

Thermodynamic Modeling for Discrete-Time Large-Scale Dynamical Systems

2011 ◽  
Author(s):  
Wassim M. Haddad ◽  
Sergey G. Nersesov
Keyword(s):  
Dynamical System ◽  
Dynamical Systems ◽  
Thermodynamic Modeling ◽  
Discrete Time ◽  
Large Scale ◽  
Type Inequality ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Thermodynamic Models ◽  
Definition Of

This chapter describes the thermodynamic modeling of discrete-time large-scale dynamical systems. In particular, it develops nonlinear discrete-time compartmental models that are consistent with thermodynamic principles. Since thermodynamic models are concerned with energy flow among subsystems, the chapter constructs a nonlinear compartmental dynamical system model characterized by conservation of energy and the first law of thermodynamics. It then provides a deterministic definition of entropy for a large-scale dynamical system that is consistent with the classical thermodynamic definition of entropy and shows that it satisfies a Clausius-type inequality leading to the law of entropy nonconservation. The chapter also considers nonconservation of entropy and the second law of thermodynamics, nonconservation of ectropy, semistability of discrete-time thermodynamic models, entropy increase and the second law of thermodynamics, and thermodynamic models with linear energy exchange.

scholarly journals REPLY TO "COMMENT ON 'FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE EFFECTS WITHIN THE FRAME OF PHYSICS' BY JOSHUA B. HALPERN, CHRISTOPHER M. COLOSE, CHRIS HO-STUART, JOEL D. SHORE, ARTHUR P. SMITH, JÖRG ZIMMERMANN"

2010 ◽  
Vol 24 (10) ◽  
pp. 1333-1359 ◽  
Author(s):  
GERHARD GERLICH ◽  
RALF D. TSCHEUSCHNER
Keyword(s):  
Heat Transfer ◽  
Radiative Heat ◽  
Second Law Of Thermodynamics ◽  
Heat Transfer Process ◽  
Trace Gas ◽  
Second Law ◽  
Heat Flows ◽  
The Earth ◽  
Greenhouse Effects ◽  
Fundamental Physical

It is shown that the notorious claim by Halpern et al. recently repeated in their comment that the method, logic, and conclusions of our "Falsification Of The CO2 Greenhouse Effects Within The Frame Of Physics" would be in error has no foundation. Since Halpern et al. communicate our arguments incorrectly, their comment is scientifically vacuous. In particular, it is not true that we are "trying to apply the Clausius statement of the Second Law of Thermodynamics to only one side of a heat transfer process rather than the entire process" and that we are "systematically ignoring most non-radiative heat flows applicable to Earth's surface and atmosphere". Rather, our falsification paper discusses the violation of fundamental physical and mathematical principles in 14 examples of common pseudo-derivations of fictitious greenhouse effects that are all based on simplistic pictures of radiative transfer and their obscure relation to thermodynamics, including but not limited to those descriptions (a) that define a "Perpetuum Mobile Of The 2nd Kind", (b) that rely on incorrectly calculated averages of global temperatures, (c) that refer to incorrectly normalized spectra of electromagnetic radiation. Halpern et al. completely missed an exceptional chance to formulate a scientifically well-founded antithesis. They do not even define a greenhouse effect that they wish to defend. We take the opportunity to clarify some misunderstandings, which are communicated in the current discussion on the non-measurable, i.e., physically non-existing influence of the trace gas CO2 on the climates of the Earth.

scholarly journals The up-scaling of ecosystem functions in a heterogeneous world

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Andrew M. Lohrer ◽  
Simon F. Thrush ◽  
Judi E. Hewitt ◽  
Casper Kraan
Keyword(s):  
Primary Productivity ◽  
Ecosystem Functioning ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Marine Ecosystem ◽  
Ecosystem Functions ◽  
Small Scale ◽  
Biodiversity Crisis ◽  
Positive Effects ◽  
Marine Habitats

Abstract Earth is in the midst of a biodiversity crisis that is impacting the functioning of ecosystems and the delivery of valued goods and services. However, the implications of large scale species losses are often inferred from small scale ecosystem functioning experiments with little knowledge of how the dominant drivers of functioning shift across scales. Here, by integrating observational and manipulative experimental field data, we reveal scale-dependent influences on primary productivity in shallow marine habitats, thus demonstrating the scalability of complex ecological relationships contributing to coastal marine ecosystem functioning. Positive effects of key consumers (burrowing urchins, Echinocardium cordatum) on seafloor net primary productivity (NPP) elucidated by short-term, single-site experiments persisted across multiple sites and years. Additional experimentation illustrated how these effects amplified over time, resulting in greater primary producer biomass (sediment chlorophyll a content) in the longer term, depending on climatic context and habitat factors affecting the strengths of mutually reinforcing feedbacks. The remarkable coherence of results from small and large scales is evidence of real-world ecosystem function scalability and ecological self-organisation. This discovery provides greater insights into the range of responses to broad-scale anthropogenic stressors in naturally heterogeneous environmental settings.

2-D random media with ellipsoidal autocorrelation functions

Geophysics ◽  
1993 ◽  
Vol 58 (9) ◽  
pp. 1359-1372 ◽  
Author(s):  
L. T. Ikelle ◽  
S. K. Yung ◽  
F. Daube
Keyword(s):  
Aspect Ratio ◽  
Seismic Data ◽  
Random Media ◽  
Large Scale ◽  
Seismic Waves ◽  
Homogeneous Medium ◽  
Small Scale ◽  
Arrival Times ◽  
The Earth ◽  
Pulse Arrival

The integration of surface seismic data with borehole seismic data and well‐log data requires a model of the earth which can explain all these measurements. We have chosen a model that consists of large and small scale inhomogeneities: the large scale inhomogeneities are the mean characteristics of the earth while the small scale inhomogeneities are fluctuations from these mean values. In this paper, we consider a two‐dimensional (2-D) model where the large scale inhomogeneities are represented by a homogeneous medium and small scale inhomogeneities are randomly distributed inside the homogeneous medium. The random distribution is characterized by an ellipsoidal autocorrelation function in the medium properties. The ellipsoidal autocorrelation function allows the parameterization of small scale inhomogeneities by two independent autocorrelation lengths a and b in the horizontal and the vertical Cartesian directions, respectively. Thus we can describe media in which the inhomogeneities are isotropic (a = b), or elongated in a direction parallel to either of the two Cartesian directions (a > b, a < b), or even taken to infinite extent in either dimension (e.g., a = infinity, b = finite: a 1-D medium) by the appropriate choice of the autocorrelation lengths. We also examine the response of seismic waves to this form of inhomogeneity. To do this in an accurate way, we used the finite‐difference technique to simulate seismic waves. Special care is taken to minimize errors due to grid dispersion and grid anisotropy. The source‐receiver configuration consists of receivers distributed along a quarter of a circle centered at the source point, so that the angle between the source‐receiver direction and the vertical Cartesian direction varies from 0 to 90 degrees. Pulse broadening, coda, and anisotropy (transverse isotropy) due to small scale inhomogeneities are clearly apparent in the synthetic seismograms. These properties can be recast as functions of the aspect ratio [Formula: see text] of the medium, especially the anisotropy and coda. For media with zero aspect ratio (1-D media), the coda energy is dominant at large angles. The coda energy gradually becomes uniformly distributed with respect to angle as the aspect ratio increases to unity. Our numerical results also suggest that, for small values of aspect ratio, the anisotropic behavior (i.e., the variations of pulse arrival times with angle) of the 2-D random media is similar to that of a 1-D random medium. The arrival times agree with the effective medium theory. As the aspect ratio increases to unity, the variations of pulse arrival times with angle gradually become isotropic. To retain the anisotropic behavior beyond the geometrical critical angle, we have used a low‐frequency pulse with a nonzero dc component.

scholarly journals Geodynamic modeling of the process of formation and evolution of lithospheric structures: experience of Schmidt institute of physics of the earth RAS

2019 ◽  
pp. 122-133
Author(s):  
V. O. Mikhailov ◽  
E. P. Timoshkina
Keyword(s):  
Large Scale ◽  
Sedimentary Basins ◽  
Geophysical Data ◽  
Small Scale ◽  
Tectonic Structures ◽  
The Earth ◽  
Basin Formation ◽  
Formation And Evolution ◽  
Geodynamic Models

Key results of numerical geodynamic modeling of the structures of the lithosphere at the Institute of Physics of the Earth of the Russian Academy of Sciences are presented. Even in the very first models, the aim of these studies was to describe the time evolution of the boundaries of the layers composing the geological structures which is required for correlating the modeling results to the geological and geophysical data. In 1983, the equation of motion for the upper boundary of the model was complemented by the allowance of sedimentation and erosion. This equation provided the basis for building the geodynamic models of the formation of various types of sedimentary basins and made it possible to mathematically analyze the problem of estimating the rates of paleotectonic movements from thickness, age, and facies composition of sedimentary layers. New data on the formation and evolution processes of large-scale tectonic structures are obtained in the model of a rheologically stratified Earth’s boundary layer, asymptotically linked to mantle convection model. In particular, the role of the small-scale convection in the formation of lithospheric structures in the tectonic settings of extension and compression has been explored. The numerical results clearly demonstrate the key role of the small-scale asthenospheric convection in sedimentary basin formation (post-rift, on passive continental margins, in foredeep basins). The constructed models served as the basis for interpretation of heterogeneous geological and geophysical data in the context of geodynamic models. The examples of statement of inverse problems are presented and the relevant bibliography is provided.

The Second Law

2021 ◽  
pp. 49-84
Author(s):  
Daniel V. Schroeder
Keyword(s):  
Simple Model ◽  
Large Scale ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
The Other ◽  
Model Systems ◽  
Second Law ◽  
Magnetic Dipoles ◽  
Einstein Model ◽  
Identical Quantum

Why are so many large-scale processes irreversible, happening in one direction but not the other as time passes? This chapter answers that question using three simple model systems: a collection of two-state particles such as flipped coins or elementary magnetic dipoles; the Einstein model of a solid as a collection of identical quantum oscillators; and a monatomic ideal gas such as helium or argon. For each system we learn to calculate the multiplicity: the number of possible microscopic arrangements. Taking the logarithm of the multiplicity gives the entropy. And the laws of probability then imply the second law of thermodynamics: Entropy tends to increase.

scholarly journals Stage Classification and Characteristics Analysis of Commercial Gentrification in Seoul

2018 ◽  
Vol 10 (7) ◽  
pp. 2440 ◽  
Author(s):  
Yoonchae Yoon ◽  
Jina Park
Keyword(s):  
Large Scale ◽  
Small Scale ◽  
Residential Areas ◽  
Korean Society ◽  
Chain Stores ◽  
Positive Effects ◽  
Mixed Use ◽  
Food And Beverage ◽  
Characteristics Analysis ◽  
District Management

Recently, local shops and small houses in Seoul have been converted to cafes, western style restaurants, and large chain stores. These changes, recognized as commercial gentrification in residential areas, are now a big issue in Korean society. This phenomenon has some positive effects, such as the emergence of new consumption spaces and improved neighborhood images. However, this study concentrated on changes in regional characteristics, landscape, and industry homogenization. This study demonstrates the presence of a cyclical environmental change process commonly identified in areas of gentrification and identifies characteristics of individual stages of the gentrification process. The results indicate that medium-scale local stores in Stage 1 changed to small-scale food and beverage businesses in Stage 2. Then, in Stage 3, they changed to large-scale clothing retailers. In particular, the process of change from Stage 2 to Stage 3 revealed that, as the diversity of business types decreases, their uses change and the proportion of chain stores increases. In other words, although Stage 2 has the highest level of mixed use and density, indicating the greatest level of vitality, commercial gentrification to Stage 3 results in decreases in use, the number of aged buildings, and density. Thus, Stage 3 can be identified as the stage in which streets lose their vitality, as suggested by Jacobs. To maintain street vitality, it is suggested that commercial district management occurs during the transformation from Stage 2 to Stage 3 of commercial gentrification.

Perceptions and Experience of Employment Regulation in UK Small Firms

2009 ◽  
Vol 27 (2) ◽  
pp. 263-278 ◽  
Author(s):  
Sara Carter ◽  
Colin Mason ◽  
Stephen Tagg
Keyword(s):  
Small Firms ◽  
Large Scale ◽  
Empirical Support ◽  
Small Scale ◽  
Negative Effects ◽  
Positive Effects ◽  
Regulatory Impact ◽  
Regulatory Effects ◽  
Small Business Growth ◽  
Employment Legislation

The view that excessive regulation constrains small business growth has been a persistent theme within business and policy communities, although recent studies have demonstrated the actual effects of regulation to be relatively modest. A prior small-scale study proposed four reasons why employment legislation does “not damage” small firms. We attempt to assess the robustness of these propositions in a large-scale survey of 16 779 small firms. Results provide empirical support for three propositions. Firstly, perceived dissatisfaction masks actual effects. Secondly, competitive conditions mediate regulatory effects; however, even resource-constrained firms reported few negative effects. Thirdly, informality eases regulatory impact. Results failed to confirm that older laws are ‘routinised’. Length of time as a business owner was found to be more influential than age of regulation, with owners who have been in business for many years having a longer ‘window of exposure’ increasing their likelihood of experiencing negative and positive effects.

scholarly journals School Vouchers: A Survey of the Economics Literature

2017 ◽  
Vol 55 (2) ◽  
pp. 441-492 ◽  
Author(s):  
Dennis Epple ◽  
Richard E. Romano ◽  
Miguel Urquiola
Keyword(s):  
Public Schools ◽  
Empirical Research ◽  
Large Scale ◽  
Single Case ◽  
Theoretical Work ◽  
Small Scale ◽  
School Vouchers ◽  
Research Approach ◽  
Positive Effects ◽  
Student Sorting

We review the theoretical, computational, and empirical research on school vouchers, with a focus on the latter. Our assessment is that the evidence to date is not sufficient to warrant recommending that vouchers be adopted on a widespread basis; however, multiple positive findings support continued exploration. Specifically, the empirical research on small-scale programs does not suggest that awarding students a voucher is a systematically reliable way to improve educational outcomes, and some detrimental effects have been found. Nevertheless, in some settings, or for some subgroups or outcomes, vouchers can have a substantial positive effect on those who use them. Studies of large-scale voucher programs find student sorting as a result of their implementation, although of varying magnitude. Evidence on both small-scale and large-scale programs suggests that competition induced by vouchers leads public schools to improve. Moreover, research is making progress on understanding how vouchers may be designed to limit adverse effects from sorting, while preserving positive effects related to competition. Finally, our sense is that work originating in a single case (e.g., a given country) or in a single research approach (e.g., experimental designs) will not provide a full understanding of voucher effects; fairly wide-ranging empirical and theoretical work will be necessary to make progress. (JEL H52, H75, I21, I22, I28, O15)

scholarly journals Planimetric Features Generalization for the Production of Small-Scale Map by Using Base Maps and the Existing Algorithms

2014 ◽  
Vol XL-2/W3 ◽  
pp. 197-201
Author(s):  
M. Modiri ◽  
M. Mohebbi ◽  
M. Masoumi ◽  
H. Khanlu ◽  
A. Eftekhari
Keyword(s):  
Production Process ◽  
Data Model ◽  
Large Scale ◽  
Flat Surface ◽  
Small Scale ◽  
Map Generalization ◽  
Logical Connection ◽  
The Earth ◽  
Cartographic Generalization

Cartographic maps are representations of the Earth upon a flat surface in the smaller scale than it’s true. Large scale maps cover relatively small regions in great detail and small scale maps cover large regions such as nations, continents and the whole globe. Logical connection between the features and scale map must be maintained by changing the scale and it is important to recognize that even the most accurate maps sacrifice a certain amount of accuracy in scale to deliver a greater visual usefulness to its user. Cartographic generalization, or map generalization, is the method whereby information is selected and represented on a map in a way that adapts to the scale of the display medium of the map, not necessarily preserving all intricate geographical or other cartographic details. Due to the problems facing small-scale map production process and the need to spend time and money for surveying, today’s generalization is used as executive approach. The software is proposed in this paper that converted various data and information to certain Data Model. This software can produce generalization map according to base map using the existing algorithm. Planimetric generalization algorithms and roles are described in this article. Finally small-scale maps with 1:100,000, 1:250,000 and 1:500,000 scale are produced automatically and they are shown at the end.

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