نتایج جستجو برای: term conservation

تعداد نتایج: 676103  

2002
Scott A. Sarra

A Chebyshev super spectral viscosity method and operator splitting are used to solve a hyperbolic system of conservation laws with a source term modeling a fluidized bed. The fluidized bed displays a slugging behavior which corresponds to shocks in the solution. A modified Gegenbauer postprocessing procedure is used to obtain a solution which is free of oscillations caused by the Gibbs–Wilbraha...

Journal: :Math. Comput. 1999
Abdallah Chalabi

We focus in this study on the convergence of a class of relaxation numerical schemes for hyperbolic scalar conservation laws including stiff source terms. Following Jin and Xin, we use as approximation of the scalar conservation law, a semi-linear hyperbolic system with a second stiff source term. This allows us to avoid the use of a Riemann solver in the construction of the numerical schemes. ...

A model for heat-recirculating micro combustor is developed. It investigates the structure of laminar, one-dimensional and steady state flame propagation in uniformly premixed wood particles with considering the effects of heat recirculation caused by configuration of micro combustor. The flame structure is divided into three regions: a preheat-devolatilization zone where the rate of the gas-ph...

Journal: :Trends in ecology & evolution 2011
Curtis H Flather Gregory D Hayward Steven R Beissinger Philip A Stephens

Establishing species conservation priorities and recovery goals is often enhanced by extinction risk estimates. The need to set goals, even in data-deficient situations, has prompted researchers to ask whether general guidelines could replace individual estimates of extinction risk. To inform conservation policy, recent studies have revived the concept of the minimum viable population (MVP), th...

2015
Brenda D. Smith-Patten Eli S. Bridge Priscilla H. C. Crawford Daniel J. Hough Jeffrey F. Kelly Michael A. Patten

Mistrust of science has seeped into public perception of the most fundamental aspect of conservation-extinction. The term ought to be straightforward, and yet, there is a disconnect between scientific discussion and public views. This is not a mere semantic issue, rather one of communication. Within a population dynamics context, we say that a species went locally extinct, later to document its...

2017
Justin Kitzes Eric Berlow Erin Conlisk Karlheinz Erb Katsunori Iha Neo Martinez Erica A. Newman Christoph Plutzar Adam B. Smith John Harte

Although most conservation efforts address the direct, local causes of biodiversity loss, effective long-term conservation will require complementary efforts to reduce the upstream economic pressures, such as demands for food and forest products, which ultimately drive these downstream losses. Here, we present a wildlife footprint analysis that links global losses of wild birds to consumer purc...

2015
Sébastien Costedoat Esteve Corbera Driss Ezzine-de-Blas Jordi Honey-Rosés Kathy Baylis Miguel Angel Castillo-Santiago

We assess the additional forest cover protected by 13 rural communities located in the southern state of Chiapas, Mexico, as a result of the economic incentives received through the country's national program of payments for biodiversity conservation. We use spatially explicit data at the intra-community level to define a credible counterfactual of conservation outcomes. We use covariate-matchi...

Journal: :Genetics 1974
O H Frankel

The conservation of the crop varieties of traditional agriculture in the centers of genetic diversity is essential to provide genetic resources for plant improvement. These resources are acutely threatened by rapid agricultural development which is essential for the welfare of millions. Methodologies for genetic conservation have been worked out which are both effective and economical. Urgent a...

2013
Jouni Paavola Klaus Hubacek

ECOSYSTEM SERVICES, GOVERNANCE, AND STAKEHOLDER PARTICIPATION: AN INTRODUCTION The ecosystem services approach has gained popularity, and novel incentive-based ecosystem conservation strategies are increasingly being used. This calls for the reassessment and transformation of conceptual-theoretical, natural resource management, and governance approaches to conservation. In the past, conservatio...

2015
Hae-Joon Jung Marc A. Rosen

Traditional rural landscapes emerged from the long term interaction of the natural and anthropogenic environment. These landscapes are now threatened by drastic social-ecological changes. Recent international trends on sustaining cultural landscapes place great emphasis on understanding of multiple values, presented in the landscape, by considering various stakeholder perspectives. It is now re...

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