Статті в журналах: "Heterogenous conservation laws"

1

Dalibard, Anne-Laure. "Kinetic formulation for heterogeneous scalar conservation laws." Annales de l'Institut Henri Poincare (C) Non Linear Analysis 23, no. 4 (July 2006): 475–98. http://dx.doi.org/10.1016/j.anihpc.2005.05.005.

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2

Mitrović, Darko, and Andrej Novak. "Transport-collapse scheme for heterogeneous scalar conservation laws." Journal of Hyperbolic Differential Equations 15, no. 01 (March 2018): 119–32. http://dx.doi.org/10.1142/s0219891618500042.

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We extend Brenier’s transport collapse scheme on the Cauchy problem for heterogeneous scalar conservation laws i.e. for the conservation laws with spacetime-dependent coefficients. The method is based on averaging out the solution to the corresponding kinetic equation, and it necessarily converges toward the entropy admissible solution. We also provide numerical examples.

3

Lv, Guangying, and Jiang-Lun Wu. "Heterogeneous stochastic scalar conservation laws with non-homogeneous Dirichlet boundary conditions." Journal of Hyperbolic Differential Equations 15, no. 02 (June 2018): 291–328. http://dx.doi.org/10.1142/s021989161850011x.

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We introduce a notion of stochastic entropy solutions for heterogeneous scalar conservation laws with multiplicative noise on a bounded domain with non-homogeneous boundary condition. Using the concept of measure-valued solutions and Kruzhkov’s semi-entropy formulations, we show the existence and uniqueness of stochastic entropy solutions. Moreover, we establish an explicit estimate for the continuous dependence of stochastic entropy solutions on the flux function and the random source function.

4

ADIMURTHI, SIDDHARTHA MISHRA, and G. D. VEERAPPA GOWDA. "OPTIMAL ENTROPY SOLUTIONS FOR CONSERVATION LAWS WITH DISCONTINUOUS FLUX-FUNCTIONS." Journal of Hyperbolic Differential Equations 02, no. 04 (December 2005): 783–837. http://dx.doi.org/10.1142/s0219891605000622.

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We deal with a single conservation law in one space dimension whose flux function is discontinuous in the space variable and we introduce a proper framework of entropy solutions. We consider a large class of fluxes, namely, fluxes of the convex-convex type and of the concave-convex (mixed) type. The alternative entropy framework that is proposed here is based on a two step approach. In the first step, infinitely many classes of entropy solutions are defined, each associated with an interface connection. We show that each of these class of entropy solutions form a contractive semigroup in L1 and is hence unique. Godunov type schemes based on solutions of the Riemann problem are designed and shown to converge to each class of these entropy solutions. The second step is to choose one of these classes of solutions. This choice depends on the Physics of the problem being considered and we concentrate on the model of two-phase flows in a heterogeneous porous medium. We define an optimization problem on the set of admissible interface connections and show the existence of an unique optimal connection and its corresponding optimal entropy solution. The optimal entropy solution is consistent with the expected solutions for two-phase flows in heterogeneous porous media.

5

Ibragimov, N. H., and Raisa Khamitova. "Conservation Laws in Thomas's Model of Ion Exchange in a Heterogeneous Solution." Interdisciplinary journal of Discontinuity, Nonlinearity, and Complexity 2, no. 2 (June 2013): 147–58. http://dx.doi.org/10.5890/dnc.2013.04.004.

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6

Aleksić, Jelena. "Gauss kernel method for generalized solutions to conservation laws in heterogeneous media." Integral Transforms and Special Functions 22, no. 4-5 (May 2011): 247–54. http://dx.doi.org/10.1080/10652469.2010.541034.

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7

Sandrakov, Gennadiy. "Modeling of Heterogeneous Hydrodynamics Processes with Phase Transition." Modeling, Control and Information Technologies, no. 3 (November 6, 2019): 67–68. http://dx.doi.org/10.31713/mcit.2019.18.

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A new mathematical and numerical method of modeling for heterogeneous hydrodynamics processes with take of phase transitions like graphite-diamond will be presented. The method is based on an approximation of conservation laws for masses, momentums, and energies in integral and differential forms. The combination of Harlow's particle-in-cell method and Belotserkovskii's large particles method is used for computing by the modeling method simulation.

8

Aleksić, Jelena, Darko Mitrovic, and Stevan Pilipović. "Hyperbolic conservation laws with vanishing nonlinear diffusion and linear dispersion in heterogeneous media." Journal of Evolution Equations 9, no. 4 (August 26, 2009): 809–28. http://dx.doi.org/10.1007/s00028-009-0035-5.

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9

Sandrakov, Gennadiy. "A Modified Method for Modeling of Heterogeneous Hydrodynamics Processes." Modeling, Control and Information Technologies, no. 4 (October 22, 2020): 63–66. http://dx.doi.org/10.31713/mcit.2020.06.

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A modified method of numerical modeling for heterogeneous fluid dynamics processes with take of phase transitions will be presented. The method is based on the homogenization on cells and approximation of conservation laws for masses, momentums, and energies in integral and differential forms. The combination of Harlow's particle-in-cell method, Belotserkovskii's large particles method and Bakhvalov's homogenization method is used for computing by the modified method simulation for processes with phase transitions.

10

Torrisi, Mariano, and Rita Tracinà. "Symmetries and Conservation Laws for a Class of Fourth-Order Reaction–Diffusion–Advection Equations." Symmetry 15, no. 10 (October 19, 2023): 1936. http://dx.doi.org/10.3390/sym15101936.

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We have studied a class of (1+1)-dimensional equations that models phenomena with heterogeneous diffusion, advection, and reaction. We have analyzed these fourth-order partial differential equations within the framework of group methods. In this class, the diffusion coefficient is constant, while the coefficients of advection and the reaction term are assumed to depend on the unknown density u(t,x). We have identified the Lie symmetries extending the Principal Algebra along with all the conservation laws corresponding to the different forms of the coefficients, and have derived several brief applications.

11

Malkina, Anna, and Anton Pastukhov. "THE DOCTRINE OF STATE AND LAW IN THE IDEOLOGICAL AND POLITICAL DOCTRINE OF CLASSICAL CONSERVATISM." 43, no. 43 (June 30, 2023): 13–21. http://dx.doi.org/10.26565/2220-8089-2023-43-02.

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This research paper explicates the basic doctrines of the State and law of classical conservatism, as well as the peculiarities of understanding and existence of the idea of the State, which follows from the conservative definition of the State. The characteristic components of this political institution are the categories of law, legal consciousness, political integrity, etc. The perception of understanding the conservative theory of the origin of the state, based on the social contract theory, as a logical continuation of the organic association of people to maintain social order and political stability, is crystallising. The latter principles are also the fundamental axiological determinants of the conservative ideological and political doctrine, whose manifestor and defender is the state. The author characterises the concepts of law and law, the conceptual basis of which is reduced to the moral sphere of existence. The main objective of the existence of laws is to protect rights and freedoms, as well as their institutional representation. At the same time, the author defines the peculiarities of understanding legal consciousness and political consciousness as fundamental elements of state-building processes. In turn, their fundamental features are historical and geographical locality, identity and conceptual authenticity, which are the basis for the constitution of heterogeneous forms of political systems. The tasks and structural elements of the theory of state in the ideological and political doctrine of conservatism are analysed. The author also identifies the institutional elements of social limitation of state power in the context of conservative doctrine, which include the church and civil society.

12

Laevsky, Yu, and T. Nosova. "Multidimensional computational models of gas combustion in heterogeneous porous medium." Journal of Physics: Conference Series 2099, no. 1 (November 1, 2021): 012010. http://dx.doi.org/10.1088/1742-6596/2099/1/012010.

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Abstract The processes of filtration gas combustion in heterogeneous porous medium is studying. The presence of two opposite modes of front propagation made it possible to stabilize the combustion front in a composite porous medium with piecewise constant porosity. A feature of this study is the presentation of the original model not in the traditional form of a system of parabolic equations, but in the form of integral conservation laws in terms of the temperature of the porous medium, the total gas enthalpy, and the mass of gas mixture, and the fluxes corresponding to these functions.

13

KESSLER, DAVID A., ELAINE S. ORAN, and CAROLYN R. KAPLAN. "Towards the development of a multiscale, multiphysics method for the simulation of rarefied gas flows." Journal of Fluid Mechanics 661 (August 2, 2010): 262–93. http://dx.doi.org/10.1017/s0022112010002934.

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We introduce a coupled multiscale, multiphysics method (CM3) for solving for the behaviour of rarefied gas flows. The approach is to solve the kinetic equation for rarefied gases (the Boltzmann equation) over a very short interval of time in order to obtain accurate estimates of the components of the stress tensor and heat-flux vector. These estimates are used to close the conservation laws for mass, momentum and energy, which are subsequently used to advance continuum-level flow variables forward in time. After a finite time interval, the Boltzmann equation is solved again for the new continuum field, and the cycle is repeated. The target applications for this type of method are transition-regime gas flows for which standard continuum models (e.g. Navier–Stokes equations) cannot be used, but solution of Boltzmann's equation is prohibitively expensive. The use of molecular-level data to close the conservation laws significantly extends the range of applicability of the continuum conservation laws. In this study, the CM3 is used to perform two proof-of-principle calculations: a low-speed Rayleigh flow and a thermal Fourier flow. Velocity, temperature, shear-stress and heat-flux profiles compare well with direct-simulation Monte Carlo solutions for various Knudsen numbers ranging from the near-continuum regime to the transition regime. We discuss algorithmic problems and the solutions necessary to implement the CM3, building upon the conceptual framework of the heterogeneous multiscale methods.

14

Delgoshaie, Amir H., Peter W. Glynn, Patrick Jenny, and Hamdi A. Tchelepi. "The stochastic counterpart of conservation laws with heterogeneous conductivity fields: Application to deterministic problems and uncertainty quantification." Journal of Computational Physics: X 2 (March 2019): 100005. http://dx.doi.org/10.1016/j.jcpx.2019.100005.

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15

Sarychev, Vladimir D., Sergey A. Nevskii, Elena V. Cheremushkina, Victor E. Gromov, and Elias C. Aifantis. "Filtration model of plastic flow." Journal of the Mechanical Behavior of Materials 23, no. 5-6 (December 1, 2014): 177–80. http://dx.doi.org/10.1515/jmbm-2014-0019.

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AbstractA filtration model for plastic flow based on the idea of a deformed material considered as a two-phase heterogeneous medium has been suggested. In this approach, the wave displacement is regarded as a shock transition in the medium. One of the phases (the excited one) is responsible for system restructuring, and the other phase (the normal one) is unrelated to structural transformations. The plastic wave is the result of the interaction of these two phases. The governing equations for the filtration model are obtained. They include the laws of momentum and mass conservation, as well as the filtration ratio of the phases.

16

Bai, Yi Long, Guang Wen Ma, Sheng Wang Hao, Meng Fen Xia, and Fu Jiu Ke. "What Happens beyond Drucker’s Proposition in Heterogeneous Media." Key Engineering Materials 535-536 (January 2013): 3–7. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.3.

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This paper briefly reviews our recent analytical and experimental results on 3 interrelated features beyond the peak load in heterogeneous media: continuous bifurcation, damage localization and catastrophic rupture (CR). Firstly, an Elastic Statistically-Brittle model (ESB) was introduced to formulate the basic features of a kind of heterogeneous media, like rocks and cements. The global mean field approximation (GMF) shows that the measure of heterogeneity, like the Weibull modulus m in the distribution of meso-strength plays a key role to distinguish CR from gradual failure. Then, with the ESB model and corresponding experimental results, continuous bifurcation and damage localization are discussed. In accord with these, regional mean field approximation (RMF) is adopted and it shows that any scale of damage localization can satisfy the conservation laws in continuum mechanics. This implies that catastrophic rupture could appear at any state beyond the peak load, depending on the unknown evolution of damage localization zone. Hence, catastrophic rupture seems to occur stochastically at macroscopic level. On the other hand, both experimental and analytic studies demonstrate that a robust power law singularity (-1/2) appears ahead of CR. Preliminary applications of these ideas are briefly described.

17

Sarychev, Vladimir D., Sergey A. Nevskii, Alexander P. Semin, and Victor E. Gromov. "Biphase Model of Plastic Deformation in Electric Fields." Journal of Metastable and Nanocrystalline Materials 30 (January 2018): 17–21. http://dx.doi.org/10.4028/www.scientific.net/jmnm.30.17.

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The object of the research is creep deformation proceeding in the conditions of electrostatic field effect. The purpose of the research is to develop the mathematical model of creep under the electrostatic field effect from the positions of representations about the wave nature of plastic deformation process. The theoretical studies of electrostatic field effect being characterized by small (up to ± 1V) potentials on the basis of mass, momentum and energy conservation in two-dimensional formulation were carried out in the process of research. The material being deformed was represented as two phase heterogeneous medium. The first component is excited and being responsible for structure transformation, the second one is unexcited and disconnected with them. For each of the components the laws of mass and momentum conservation were written. For electric fields the Maxwell equations were written. For the first time the two phase filtration model of creep was developed as a result of the research. The model takes into account the inhomogeneity of plastic deformation under electrostatic field effect. The dispersion relation for the waves of plasticity is obtained.

18

Correa, M. R., and M. R. Borges. "A semi-discrete central scheme for scalar hyperbolic conservation laws with heterogeneous storage coefficient and its application to porous media flow." International Journal for Numerical Methods in Fluids 73, no. 3 (April 15, 2013): 205–24. http://dx.doi.org/10.1002/fld.3794.

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19

FAN, Peifeng, Hong QIN, and Jianyuan XIAO. "Discovering exact, gauge-invariant, local energy–momentum conservation laws for the electromagnetic gyrokinetic system by high-order field theory on heterogeneous manifolds." Plasma Science and Technology 23, no. 10 (August 27, 2021): 105103. http://dx.doi.org/10.1088/2058-6272/ac18ba.

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20

Brent, Daniel A., Corey Lott, Michael Taylor, Joseph Cook, Kimberly Rollins, and Shawn Stoddard. "What Causes Heterogeneous Responses to Social Comparison Messages for Water Conservation?" Environmental and Resource Economics 77, no. 3 (September 4, 2020): 503–37. http://dx.doi.org/10.1007/s10640-020-00506-0.

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21

Galtsev, Oleg V., Oksana A. Galtseva, Vladimir A. Belenko, Alexander V. Mamatov, Alexander N. Nemtsev, and Vadim V. Mishunin. "Numerical Solution of Rare Metal Leaching Problem." International Journal of Engineering & Technology 7, no. 4.36 (December 1, 2018): 5. http://dx.doi.org/10.14419/ijet.v7i4.36.22703.

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It is well known that a lot of chemical and physical processes take place on the surfaces of interaction between solid and liquid substances. These processes include a very important technological process of uranium, nickel, copper, precious metal and other solid compound extraction - in-situ leaching. In this article we will rely on the mathematical description of these complex systems proposed by A.M. Meirmanov, where the main idea is the presence of new conditions on a free (unknown) boundary between liquid and solid phases (“pore space - solid skeleton”). These conditions express the usual laws of mass conservation of mass and the development of the mathematical model describing the processes at the macroscopic level. The method proposed in the book allows us to study numerically the dependence ways of free boundary dynamics on a heterogeneous solution distribution velocity and external parameters (reagent temperature, pressure and concentration).

22

Zhong, Zhong, Wei Lu, Shuai Song, and Yaocun Zhang. "A New Scheme for Effective Roughness Length and Effective Zero-Plane Displacement in Land Surface Models." Journal of Hydrometeorology 12, no. 6 (December 1, 2011): 1610–20. http://dx.doi.org/10.1175/2011jhm1375.1.

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Abstract Based on the similarity theory of the atmospheric surface layer and the flux conservation and mass conservation laws, a new scheme for determining the effective roughness length (ERL) and the effective zero-plane displacement (EZPD) for a heterogeneous terrain is proposed. The test for a two-category system case shows that the ERL (EZPD) is larger (smaller) than the area-weighted logarithmic (linear) averaged one, whereas differences between the new ERL/EZPD and their average values are increased with roughness ratio and rough-portion zero-plane displacement (RZPD) in the grid square. Though the ERL and EZPD show some dependence on atmospheric stability, they can be treated as constants in the land surface models unless the seasonal variation must be taken into account. This is due to the fact that the error percentage of the effective drag coefficients, which are dependent on the ERL and EZPD, is less than 2% under all stability conditions. Moreover, the dynamical effects of the underlying surface can be represented jointly by the ERL and the EZPD, either for a heterogeneous terrain or for a homogeneous terrain with high obstacles. The enhancement effect of the roughness ratio on ERL and EZPD is magnified by the RZPD. However, the ratio of rough area over smooth area, where the maximum ratio of ERL over the area-weighted mean as well as the maximum difference between EZPD and area-weighted mean occurs, is dependent on the roughness ratio but independent of the RZPD. The ERLs computed by this new model are also compared with other schemes and large-eddy simulation, where the effect of RZPD is not considered.

23

BERNACKI, MARC, STEPHANE LANTERI, and SERGE PIPERNO. "TIME-DOMAIN PARALLEL SIMULATION OF HETEROGENEOUS WAVE PROPAGATION ON UNSTRUCTURED GRIDS USING EXPLICIT, NONDIFFUSIVE, DISCONTINUOUS GALERKIN METHODS." Journal of Computational Acoustics 14, no. 01 (March 2006): 57–81. http://dx.doi.org/10.1142/s0218396x06002937.

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A general Discontinuous Galerkin framework is introduced for symmetric systems of conservations laws. It is applied to the three-dimensional electromagnetic wave propagation in heterogeneous media, and to the propagation of aeroacoustic perturbations of either uniform or nonuniform, steady solutions of the three-dimensional Euler equations. In all these linear contexts, the time evolution of some quadratic wave energy is given in a balance equation, with a volumic source term for aeroacoustics in a nonuniform flow. An explicit leap-frog time scheme along with centered numerical fluxes are used in the proposed Discontinuous Galerkin Time Domain (DGTD) method, in order to achieve a discrete equivalent of the balance equation for the wave energy. The scheme introduced is genuinely nondissipative. Numerical first-order boundary conditions are developed to bound the domain and stability is proved on arbitrary unstructured meshes and discontinuous finite elements, under some CFL-like stability condition on the time step. Numerical results obtained with a parallel implementation of the method based on mesh partitioning and message passing are presented to show the potential of the method.

24

Berdyshev, Abdumauvlen, Kholmatzhon Imomnazarov, Jian-Gang Tang, and Aleksander Mikhailov. "The Laguerre spectral method as applied to numerical solution of a two−dimensional linear dynamic seismic problem for porous media." Open Computer Science 6, no. 1 (December 30, 2016): 208–12. http://dx.doi.org/10.1515/comp-2016-0018.

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AbstractThe initial boundary value problem of the dynamics of fluid saturated porous media, described by three elastic parameters in the reversible hydrodynamic approximation, is numerically solved. A linear two-dimensional problem as dynamic equations of porous media for components of velocities, stresses and pore pressure is considered. The equations of motion are based on conservation laws and are consistent with thermodynamic conditions. In this case, a medium is considered to be ideally isotropic (in the absence of energy dissipation) and twodimensional heterogeneous with respect to space. For a numerical solution of the dynamic problem of poroelasticity we use the Laguerre transform with respect to time and the finite difference technique with respect to spatial coordinates on the staggered grids with fourth order of accuracy. The description of numerical implementation of the algorithm offered is presented, and its characteristics are analyzed. Numerical results of the simulation of seismic wave fields for the test layered models have been obtained on the multiprocessor computer.

25

Sandrakov, Gennadiy. "Computational Fluid Mechanics with Phase Transitions by Particle Methods." Modeling Control and Information Technologies, no. 6 (November 22, 2023): 90–91. http://dx.doi.org/10.31713/mcit.2023.025.

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A computational method of simulations for processes of heterogeneous hydrodynamics with take of phase transitions will be discussed. The method is based on relevant approximation of conservation laws for mass, momentum, and energy in integral and differential forms. The time and spatial approximation is natural and numerical simulations are realized as direct computer experiments. It is supposed that the fluids are compressible and non-viscous. Heterogeneities of the fluids are considered as small drops or particles of one fluid within other fluid. Total number of the drops may be large enough and the drops may have phase transitions. Therefore, simulations of the main fluid with small transited drops dynamics are considered. The particle dynamics will be modelled as in the particle-in-cell method, and in the main fluid as in the large particle method. This approach makes it possible to simulate phase transitions under certain assumptions about heterogeneous fluids. The calculation algorithm of this method is implemented as a computer simulation of the dynamics of a multiphase carrier fluid containing particles that can undergo, for example, graphite-diamond phase transitions. Such transitions are modelled on the basis of the theory of phase transformations and the laws of thermodynamics. In fact, the method is a combination of the Harlow's particle-in-cell method, Belotserkovskii's large particles method and Bakhvalov's homogenization method. A modification of this method has also been developed to take into account the effects of viscosity when simulating the dynamics of a multiphase fluid in porous media. A model of the motion of such a liquid in a porous medium is obtained by freezing the motion of particles of the corresponding size in the presented method. The method will certainly be promising for numerical simulations of absorption and diffusion processes in complex fluids with phase transitions.

26

Li, Li, Atsushi Tsunekawa, Yangshangyu Zuo, and Atsushi Koike. "Conservation Payments and Technical Efficiency of farm Households Participating in the Grain for Green Program on the Loess Plateau of China." Sustainability 11, no. 16 (August 16, 2019): 4426. http://dx.doi.org/10.3390/su11164426.

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This study provides an empirical analysis of household technical efficiency and its determinant factors (especially conservation payments) in the context of the Grain for Green program. On the basis of a sample of 225 farm households on the Loess Plateau in 2007, we estimate household technical efficiency using the data envelopment analysis method. In addition to a traditional ordinary least square (OLS) analysis, quantile regression (QR) analysis is also deployed to explore the possible heterogeneous effects of conservation payments and other variables on the technical efficiency across the quantiles. The results suggest that when off-farm activities are taken into account, households have considerable potential for improving their technical efficiency; OLS analysis shows that conservation payments decrease household efficiency, and the QR analysis suggests that the negative impact is significant only for higher performance households; The presence of children, access of households to leased land markets, credit markets, and extension services all show heterogeneous impacts on household efficiency. On the basis of the findings of the study, policies suggestions to improve the program’s effectiveness are provided.

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Mari, László, Zsófia Tábori, Ivan Šulc, Petra Radeljak Kaufmann, Ranko Milanović, Alena Gessert, Zoltán Imecs, Anetta Baricz, and Tamás Telbisz. "The system and spatial distribution of protected areas in Hungary, Slovakia, Romania, Serbia and Croatia." Hungarian Geographical Bulletin 71, no. 2 (June 30, 2022): 99–115. http://dx.doi.org/10.15201/hungeobull.71.2.1.

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Protected areas play a key role in nature conservation but are also crucial for tourism. There are international recommendations in nature conservation (IUCN), and several international conservation conventions exist. Nevertheless, the protection categories are different in each country, and the proportion of protected areas also varies. Here we compare the nature conservation systems of some countries (Hungary, Slovakia, Romania, Serbia and Croatia) taking into consideration their nature protection laws. The selection of countries is based on an international project dealing with “Karst and National Parks”. For the comparison, national data sources and an international database (WDPA) are used. Our results show that the protection categories of the studied countries are largely similar, but there are unique characteristics as well (such as “forest park”, “monument of park architecture” in Croatia; “nature conservation area” in Hungary or “protected landscape element” in Slovakia, etc.). On the other hand, the internal proportions of protection categories are more heterogeneous, like, for example, the proportion of national parks within all protected areas which is 57.0 percent in Hungary but 11 percent in Croatia. International protection categories (Natura 2000, Ramsar, UNESCO World Heritage natural sites, UNESCO MAB reserves) are more or less similarly present in the countries studied (except Serbia, where there are no Natura 2000 areas yet). If national categories and Natura 2000 sites are all taken into consideration (and the overlapping areas are counted only once), then Croatia has the highest proportion of protected areas (39.1%), Slovakia is in second place with 37.5 percent, while Romania (23.5%) and Hungary (22.0%) show a similar proportion, and with the lack of Natura 2000, Serbia has 9.1 percent at present. As for the reliability of the WDPA, we found that this varies from country to country, with significant deficiencies for certain countries (e.g. Serbia) and very good reliability for others (e.g. Hungary, Slovakia). However, the availability of WDPA is in many cases better than that of national data, and since it also provides GIS data, it can be considered a useful tool for examining international trends and mapping protected areas.

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Abdallah, Adel M., and David E. Rosenberg. "Heterogeneous Residential Water and Energy Linkages and Implications for Conservation and Management." Journal of Water Resources Planning and Management 140, no. 3 (March 2014): 288–97. http://dx.doi.org/10.1061/(asce)wr.1943-5452.0000340.

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29

Hoteit, Hussein, and Abbas Firoozabadi. "Compositional Modeling by the Combined Discontinuous Galerkin and Mixed Methods." SPE Journal 11, no. 01 (March 1, 2006): 19–34. http://dx.doi.org/10.2118/90276-pa.

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Summary In this work, we present a numerical procedure that combines the mixed finite-element (MFE) and the discontinuous Galerkin (DG) methods. This numerical scheme is used to solve the highly nonlinear coupled equations that describe the flow processes in homogeneous and heterogeneous media with mass transfer between the phases. The MFE method is used to approximate the phase velocity based on the pressure (more precisely average pressure) at the interface between the nodes. This approach conserves the mass locally at the element level and guarantees the continuity of the total flux across the interfaces. The DG method is used to solve the mass-balance equations, which are generally convection-dominated. The DG method associated with suitable slope limiters can capture sharp gradients in the solution without creating spurious oscillations. We present several numerical examples in homogeneous and heterogeneous media that demonstrate the superiority of our method to the finite-difference (FD) approach. Our proposed MFE-DG method becomes orders of magnitude faster than the FD method for a desired accuracy in 2D. Introduction There has been gradual progress in the development of algorithms for the compositional simulation of hydrocarbon reservoirs in the last 15 years. Before that, there were several major advances in the numerical solution of the combined flow equations and the thermodynamic equilibrium with the equations of state. Despite the advances of the last 25 to 30 years and the enormous progress in the speed of computers in the same period, we cannot yet perform field-scale compositional modeling satisfactorily in heterogeneous reservoirs. The main problem is the continued use of the FD discretization scheme and its inherent limitations. Most of the current compositional simulators use the upstream weighted FD method to approximate the flow equations. Because of the fact that the flow processes are usually convection-dominated, FD methods may produce significant numerical diffusion (Coats 1980). The excessive numerical diffusion requires unrealistic gridding, especially with heterogeneities. Recently, the DG methods have been successfully implemented to approximate various physical problems, notably hyperbolic systems of conservative laws. One property of these methods is that they conserve mass at the element level in a finite-element framework. Consequently, they enhance the flexibility of finite elements in describing flow in complicated geometries. Furthermore, the choice of the spatial approximation without the continuity across inter-element boundaries allows a simple treatment of combined finite-element cells with different geometries as well as different degrees of approximating polynomials. These methods associated with suitable slope limiters can capture discontinuities or sharp gradients in the solution. The DG method was first implemented for nonlinear scalar conservative laws by Chavent and Salzano (1982). However, these authors noted that a very restrictive timestep should be used to keep stability of the scheme.

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Bondarenko, A., M. Savin, O. Supotnitskaya, and L. Yantseva. "ON COMBINED BURNING RATE OF LIQUID SODIUM STREAM AND POOL." PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. SERIES: NUCLEAR AND REACTOR CONSTANTS 2019, no. 1 (March 26, 2019): 224–29. http://dx.doi.org/10.55176/2414-1038-2019-1-224-229.

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Sodium fires with heat and fume release often happen at coolant circuit rupture of sodium fast reactor. At nuclear power plant with the sodium fast reactor the more probable scenario of sodium fire is considered burning of falling from damaged pipeline liquid sodium stream and the pool formed under it. The simple models for sodium fire which contains minimum of phenomenological parameters and gives the opportunity to get the upper limits of heat generation and amount of aerosol generated at sodium fire are more preferable. The physical and mathematical model for estimation a combined burning rate of the freely falling liquid sodium stream and the pool formed under it is proposed. The model is based on the laws of energy and mass conservation, the empiric correlations for burning rate of stream and pool sodium and assumption that pool depth cannot be less than equilibrium. The equilibrium pool depth depends on surface tension of liquid sodium. The probable heat transfer techniques for steam-phase and heterogeneous burning of metal are discussed. The experimental data of the Monju's sodium fire imitation are used for verification of the model presented. Good agreement between experimental and calculated data is observed.

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Chesterton, Chris. "Determining suitable grazing levels on heterogeneous vegetation." International Journal of Biodiversity Science & Management 2, no. 3 (September 2006): 245–46. http://dx.doi.org/10.1080/17451590609618135.

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Shen, Hongcheng, and Yi Liu. "Can Circular Economy Legislation Promote Pollution Reduction? Evidence from Urban Mining Pilot Cities in China." Sustainability 14, no. 22 (November 8, 2022): 14700. http://dx.doi.org/10.3390/su142214700.

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Major economies, such as the United States, European Union (EU), Japan, and China have enacted Circular Economy Promotion Laws (CEPLs) to promote the development of the recycling industry. The Urban Mining Pilot Policy (UMPP) is an essential provision of the CEPL in China, which promotes a circular economy and environmentally friendly industries and society. In China, the Urban Mining Pilot City (UMPC) program facilitates the addressing of the negative environmental impacts of industrial and urban waste, and conservation of scarce primary resources, which are necessary for sustainable industrialization and urban sustainability in developing countries. In the present study, a time-varying difference-in-difference analysis of city-level panel data was conducted to investigate the impact of the UMPC program on pollution reduction in China. The results indicated that the UMPC program has improved municipal waste management efficiency and environmental quality significantly, with robust results across various models and datasets. Additionally, the mediation test showed the positive impacts of the UMPC program are mainly associated with the economy-of-scale effects. Finally, the UMPP had geographical and social-economic heterogeneous effects. To the best of our knowledge, this is the first study to quantify the impact of the UMPC program on recyclable solid waste management and pollution reduction in urban China, with potential contributions to resource and environmental economics.

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Yu, Ziao, Tianjiao Guo, Xiaoqian Song, Lifan Zhang, Linmei Cai, Xi Zhang, and Aiwen Zhao. "Green Transition Assessment, Spatial Correlation, and Obstacles Identification: Evidence from Urban Governance Data of 288 Cities in China." Land 13, no. 3 (March 7, 2024): 341. http://dx.doi.org/10.3390/land13030341.

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The green transition of China’s cities is crucial for ecology civilization realization. Based on the driver–pressure–state–impact–response (DPSIR) framework, an integrated technique for order preference by similarity to ideal solution (TOPSIS) model with entropy weight, this study achieved the comprehensive assessment of the green transition of 288 province-level municipalities and prefecture-level cities in China over 18 years from 2002 to 2019, in addition to the spatial correlations and obstacles analysis. The results indicate that major cities in China have a more significant green transition value, and the eastern region is developing fast, while the northeast region is relatively slow. There was heterogeneous spatial distribution for green transition, because of the disequilibrium sustainable development of 288 cities. Green transition has a significantly positive spatial autocorrelation in the cities of China, the high–high significant clusters greatly increased, and the main locations changed from the northeast to southeast of China. Frequent obstacles were also found, including road infrastructure construction, water resources, and the green coverage of urban built-up areas. Based on these results, several policy implications were put forward, including the optimization of environmental laws and regulations, the development of green transportation infrastructure, resource conservation and the circular economy, the establishment of a green financial system, and increasing the linkage for the green transition of different cities.

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Oniki, Shunji, Haftu Etsay, Melaku Berhe, and Teklay Negash. "Improving Cooperation among Farmers for Communal Land Conservation in Ethiopia: A Public Goods Experiment." Sustainability 12, no. 21 (November 9, 2020): 9290. http://dx.doi.org/10.3390/su12219290.

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Farmers in developing countries depend on communal natural resources, yet countries in Sub-Saharan Africa are facing the severe degradation of communal lands due to the so-called “tragedy of the commons”. For the sustainable management of common resources, policy interventions, such as farmer seminars, are necessary to ensure high-level cooperation among farmers for land conservation. However, the effects of this type of information provision are not well known. The purpose of this study is to examine the effects of the dissemination of conservation information on collaborative communal forest management using an economic field experiment with 936 farmers selected by random sampling from 11 villages in the northern Ethiopian Highlands. We conducted a public goods game experiment using a framework of voluntary contribution to communal land conservation with an intervention to remind participants about the consequence of their behaviors. The results show that the volunteer contribution increased after the intervention, and thereafter the decay of the contribution was slow. The results indicate that providing information about the consequences leads to a higher contribution. The effects of information provision are heterogeneous in terms of social condition, such as access to an urban area and social capital, and individual characteristics, such as wealth. These findings imply that information provision effectively improves farmer collaboration toward natural resource conservation in developing countries.

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Davi, H., F. Baret, R. Huc, and E. Dufrêne. "Effect of thinning on LAI variance in heterogeneous forests." Forest Ecology and Management 256, no. 5 (August 2008): 890–99. http://dx.doi.org/10.1016/j.foreco.2008.05.047.

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Morris, Douglas W. "How can we apply theories of habitat selection to wildlife conservation and management?" Wildlife Research 30, no. 4 (2003): 303. http://dx.doi.org/10.1071/wr02028.

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Habitat-selection theory can be applied to solve numerous problems in the conservation and management of wildlife. Many of the solutions involve the use of habitat isodars, graphs of densities in pairs of habitats such that expected fitness is the same in both. For single species, isodars reflect differences in habitat quality, and specify the conditions when population density will, or will not, match the abundance of resources. When two or more species co-occur, isodars can be used to assess not only whether the species compete with one another, but also differences in habitat, in habitat selection, and in the functional form of density-dependent competition. Isodars have been applied to measure scales of habitat selection, the presence or absence of edge effects, as well as the number of habitats that species recognise in heterogeneous landscapes. Merged with foraging behaviour, isodars reveal the relative roles of habitat selection, spatial structure, and environmental stochasticity on local populations. Habitat-selection models can be linked similarly with theories of patch use to assess the underlying cause of source–sink dynamics. Isodars can detect and measure Allee effects, describe human habitat selection, and use human occupation of habitat as a leading indicator of threatened biodiversity. Even so, we have only begun to reveal the potential of habitat selection, and other optimal behaviours, to solve pressing problems in conservation and management.

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Nehiba, Cody. "Correcting Heterogeneous Externalities: Evidence from Local Fuel Taxes." Journal of the Association of Environmental and Resource Economists 9, no. 3 (May 1, 2022): 495–529. http://dx.doi.org/10.1086/717418.

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Mangewa, Lazaro J., Patrick A. Ndakidemi, and Linus K. Munishi. "Integrating UAV Technology in an Ecological Monitoring System for Community Wildlife Management Areas in Tanzania." Sustainability 11, no. 21 (November 3, 2019): 6116. http://dx.doi.org/10.3390/su11216116.

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Unmanned aerial vehicles (UAV) have recently emerged as a new remote sensing aerial platform, and they are seemingly advancing real-time data generation. Nonetheless, considerable uncertainties remain in the extent to which wildlife managers can integrate UAVs into ecological monitoring systems for wildlife and their habitats. In this review, we discuss the recent progress and gaps in UAV use in wildlife conservation and management. The review notes that there is scanty information on UAV use in ecological monitoring of medium-to-large mammals found in groups in heterogeneous habitats. We also explore the need and extent to which the technology can be integrated into ecological monitoring systems for mammals in heterogeneous habitats and in topographically-challenging community wildlife-management areas, as a complementary platform to the traditional techniques. Based on its ability to provide high-resolution images in real-time, further experiments on its wider use in the ecological monitoring of wildlife on a spatiotemporal scale are important. The experimentation outputs will make the UAV a very reliable remote sensing platform that addresses the challenges facing conventional techniques.

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Puerta-Piñero, Carolina, José M. Gómez, and Fernando Valladares. "Irradiance and oak seedling survival and growth in a heterogeneous environment." Forest Ecology and Management 242, no. 2-3 (April 2007): 462–69. http://dx.doi.org/10.1016/j.foreco.2007.01.079.

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Niskanen, Olli, Annika Tienhaara, Emmi Haltia, and Eija Pouta. "Farmers’ heterogeneous preferences towards results-based environmental policies." Land Use Policy 102 (March 2021): 105227. http://dx.doi.org/10.1016/j.landusepol.2020.105227.

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Lines, Robin, Dimitrios Bormpoudakis, Panteleimon Xofis, and Joseph Tzanopoulos. "Modelling Multi-Species Connectivity at the Kafue-Zambezi Interface: Implications for Transboundary Carnivore Conservation." Sustainability 13, no. 22 (November 21, 2021): 12886. http://dx.doi.org/10.3390/su132212886.

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Linking wildlife areas with corridors facilitating species dispersal between core habitats is a key intervention to reduce the deleterious effects of population isolation. Large heterogeneous networks of areas managed for wildlife protection present site- and species-scale complexity underpinning the scope and performance of proposed corridors. In Southern Africa, the Kavango-Zambezi Transfrontier Conservation Area seeks to link Kafue National Park to a cluster of wildlife areas centered in Namibia and Botswana. To assess and identify potential linkages on the Zambian side, we generated a high-resolution land cover map and combined empirical occurrence data for Lions (Panthera leo), Leopards (Panthera pardus) and Spotted Hyena (Crocuta crocuta) to build habitat suitability maps. We then developed four connectivity models to map potential single and multi-species corridors between Kafue and the Zambezi River border with Namibia. Single and multi-species connectivity models selected corridors follow broadly similar pathways narrowing significantly in central-southern areas of the Kafue-Zambezi interface, indicating a potential connectivity bottleneck. Capturing the full extent of human disturbance and barriers to connectivity remains challenging, suggesting increased risk to corridor integrity than modelled here. Notwithstanding model limitations, these data provide important results for land use planners at the Kafue-Zambezi Interface, removing much speculations from existing connectivity narratives. Failure to control human disturbance and secure corridors will leave Kafue National Park, Zambia’s majority component in the Kavango-Zambezi Transfrontier Conservation Area, isolated.

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Lozano, Julian E., Katarina Elofsson, and Yves Surry. "Heterogeneous impacts of large carnivores on hunting lease prices." Land Use Policy 101 (February 2021): 105215. http://dx.doi.org/10.1016/j.landusepol.2020.105215.

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Maltamo, M., P. Packalén, X. Yu, K. Eerikäinen, J. Hyyppä, and J. Pitkänen. "Identifying and quantifying structural characteristics of heterogeneous boreal forests using laser scanner data." Forest Ecology and Management 216, no. 1-3 (September 2005): 41–50. http://dx.doi.org/10.1016/j.foreco.2005.05.034.

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Chamberlain, Caden P., Gina R. Cova, C. Alina Cansler, Malcolm P. North, Marc D. Meyer, Sean M. A. Jeronimo, and Van R. Kane. "Consistently heterogeneous structures observed at multiple spatial scales across fire-intact reference sites." Forest Ecology and Management 550 (December 2023): 121478. http://dx.doi.org/10.1016/j.foreco.2023.121478.

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Kowalski, Julia, and Jim N. McElwaine. "Shallow two-component gravity-driven flows with vertical variation." Journal of Fluid Mechanics 714 (January 2, 2013): 434–62. http://dx.doi.org/10.1017/jfm.2012.489.

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AbstractGravity-driven geophysical mass flows often consist of a heterogeneous fluid–solid mixture. The complex interplay between the components leads to phenomena such as lateral levee formation in avalanches, or a granular front and an excess fluid pore pressure in debris flows. These effects are very important for predicting runout and the forces on structures, yet they are only partially represented in simplified shallow flow theories, since rearrangement of the mixture composition perpendicular to the main flow direction is neglected. In realistic flows, however, rheological properties and effective basal drag may depend strongly on the relative concentration of the components. We address this problem and present a depth-averaged model for shallow mixtures that explicitly allows for rearrangement in this direction. In particular we consider a fluid–solid mixture that experiences bulk horizontal motion, as well as internal sedimentation and resuspension of the particles, and therefore resembles the case of a debris flow. Starting from general mixture theory we derive bulk balance laws and an evolution equation for the particle concentration. Depth-integration yields a shallow mixture flow model in terms of bulk mass, depth-averaged particle concentration, the particle vertical centre of mass and the depth-averaged velocity. This new equation in this model for the particle vertical centre of mass is derived by taking the first moment, with respect to the vertical coordinate, of the particle mass conservation equation. Our approach does not make the Boussinesq approximation and results in additional terms coupling the momentum flux to the vertical centre of mass. The system is hyperbolic and reduces to the shallow-water equations in the homogeneous limit of a pure fluid or perfect mixing. We highlight the effects of sedimentation on resuspension and finally present a simple friction feedback which qualitatively resembles a large-scale experimental debris flow data set acquired at the Illgraben, Switzerland.

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Vanin, Viktor. "MATHEMATICAL MODELS, NUMERICAL METHODS AND RESULTS OF STUDY OF TRANSSONIC FLOW AROUND PROFILES OF BLADE SYSTEMS." Bulletin of the National Technical University "KhPI". Series: Mathematical modeling in engineering and technologies, no. 1 (August 1, 2023): 23–28. http://dx.doi.org/10.20998/2222-0631.2023.01.04.

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The aerodynamic characteristics of blade profiles in a transonic flow of an ideal gas are considered, which are obtained on the basis of the numerical solution of the system of gas dynamics equations (laws of conservation) in integral form. The solution is found by stabilizing over time, which avoids complications in the numerical method for a stationary system of variable-type equations with unknown lines of change from elliptic to hyperbolic and vice versa. The peculiarities of the position of the shock wave (jump) depending on the algorithm for calculating the parameter values on the faces of the cells of the difference grid in the finite-volume algorithm are pointed out. The calculation of numerical flows on the faces of the volume is based on the solution of the problem of the decay of an arbitrary discontinuity of parameters on them in a one-dimensional direction along the normal to the face. The choice of the working difference scheme is based on the indicators of accuracy (order of approximation) and complexity (explicit and implicit) of transition to the next time layer. The development of difference schemes of a higher order of approximation allows to obtain more detailed information about gas-dynamic flows on real grids, which was unattainable when using schemes of the first order of accuracy with high scheme (approximation) viscosity and inconsistency of the propagation of disturbances on a heterogeneous background of parameter values (dispersion calculation effects). The results of calculations using S.K. Godunov's scheme of a higher order of approximation, aerodynamic characteristics of the rigid profile and their comparison with experimental data are given. The characteristics of a profile that performs incoherent angular and vertical oscillations according to a given law are studied.

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Ji, Jiahui, and Tim Heath. "The Spatial Transformation of the Villages around Chang’an Cultural Heritage Site Based on Actor Network Theory." Sustainability 15, no. 14 (July 11, 2023): 10846. http://dx.doi.org/10.3390/su151410846.

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The villages around a Cultural Heritage Site (CHS), despite being influenced by long-term restrictive conservation policies for protecting their heritage’s integrity, are often excluded from heritage recognition. They do, however, have opportunities to develop tourism and become places involving multiple stakeholders to alleviate the tension between cultural heritage conservation and the sustainable development of the village. As a result, the villages around a Cultural Heritage Site have been faced with much more complex situations than the sites themselves, as more stakeholders participate in and invoke the profound transformation of the space. To clarify this complex spatial transformation and bring about sustainable development, Lougetai village around the Chang’an Cultural Heritage Site, one of the heritage-led tourism villages, is taken as a case study to elucidate the spatial mechanism by applying Actor Network Theory. To achieve this, the multiple actors involved in the process of tourism projects and concomitant spatial transformation are investigated based on: (i) an archival study; (ii) participant observation; and (iii) semi-structured interviews. Our findings are as follows: (1) Lougetai village experienced profound spatial transformation into a heritage-led tourism destination, with residential, communication, and production spaces added, together with commercial space; (2) the process of constructing the heritage-led tourism destination included a heterogeneous actor network in which the Weiyang District Government played a vital role in enrolling other actors to participate, including the village committee, professionals, investors, tourists, and local people; (3) in the process of constructing the heritage-led tourism destination, the interests, intentions, and actions of heterogeneous actors can affect the village’s development. This complicated mechanism is identified from a detailed analysis of the implemented strategies and interests of diverse actors. These findings provide an understanding of the process of establishing heritage-led tourism and can be used to support future research in relation to the sustainable development of the villages around a Cultural Heritage Site.

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Li, Jirui, Junsheng Xiao, and Jie Yuan. "Two-Tier Cooperation Based High-Reliable and Lightweight Forwarding Strategy in Heterogeneous WBAN." Sustainability 15, no. 6 (March 22, 2023): 5588. http://dx.doi.org/10.3390/su15065588.

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Due to the limited and difficult access to sensor energy, energy conservation has always been an important issue in wireless body area network (WBAN). How to make full use of the limited energy of heterogeneous sensors in WBAN to achieve lightweight and high-reliable data transmission has also become key to the sustainable development of telemedicine services. This paper proposes a two-tier cooperation based high-reliable and lightweight forwarding (TTCF) mechanism via minimizing the amount of transmitted data and optimizing forwarding performance, so as to improve the efficiency and reliability of WBAN and reduce system energy consumption. In TTCF, an adaptive semi-tensor product compressed sensing evolution (STPCSE) model is first constructed to minimize the amount of data to be transmitted and extend the lifetime of sensors. Then, the important factors closely related to the energy consumption of human body sensors, including sampling frequency, residual energy and their importance in the network, are analyzed and redefined, and a high-reliable and lightweight forwarding model based on a multi-factor dynamic fusion is built. Finally, the performance and energy-saving effect of TTCF in a dynamic WBAN environment are compared and analyzed. Simulation results show that the system with our TTCF always performs the best in terms of data reconstruct accuracy, cumulative delivery rata, energy consumption and throughput. For example, its cumulative delivery rate is about 12% and 20.8% higher than that of UC-MPRP and CRPBA, and its residual energy and throughput are 1.22 times and 1.41 times, 1.35 times and 1.6 times of the latter two, respectively.

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Modak, Biplob Kumar, Subha Shankar Mukherjee, Susobhan Mondal, Mainak Sarkar, and Asif Hossain. "Diversity of wintering avifauna throughout the heterogeneous aquatic habitats of Bankura District, West Bengal, India." Journal of Threatened Taxa 15, no. 12 (December 26, 2023): 24321–30. http://dx.doi.org/10.11609/jott.7647.15.12.24321-24330.

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Birds play various crucial roles in the ecosystem including pollination, seed dispersal, and pest control. Assemblages of bird species in a particular landscape are useful predictors in various ecosystem services, this is evident from studies of forest bird assemblages, aquatic bodies and agro ecosystems. For developing conservation strategies, information on bird species assemblages in a particular geographical area is important. Diversity in aquatic ecosystem support a diversity of water bird species. In the present study, around 45 bird species were recorded in 21 aquatic bodies in Bankura, West Bengal, India, in which two species, namely, Leptoptilos javanicus and Aythya ferina declared ‘Vulnerable’ and three species such as Mareca falcata, Threskiornis melanocephalus, and Limosa limosa considered as ‘Near Threatened’ according to the IUCN Red list. Dendrocygna javanica and Nettapus coromandelianus were found to be the most abundant. In those 21 study areas, site6 has the highest species richness and site2 has the lowest. The dominance index was highest for site2 and lowest for site6. Pielou’s index of evenness was highest for site20. The rarefaction curve showed species abundance was highest for site1. Classical cluster analysis for species abundance showsthat site20, site21, site3, site8, site4, site19, site5, site14, site12, site15, site7, site 10 site11, and site13 are closely related. This paper is aimed to generate interest among people to conserve aquatic birds and their habitats and to document baseline information for further study.

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Taylor, Peter J., Sarah Downs, Ara Monadjem, Seth J. Eiseb, Loth S. Mulungu, Apia W. Massawe, Themb'a A. Mahlaba, et al. "Experimental treatment-control studies of ecologically based rodent management in Africa: balancing conservation and pest management." Wildlife Research 39, no. 1 (2012): 51. http://dx.doi.org/10.1071/wr11111.

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Context Rodent pests severely affect crop production, particularly in monocultures where one or two rodent pest species dominate. We predict higher species richness of native small mammal species in more heterogeneous mosaic (crop–fallow–bush) subsistence agro-ecosystems in Africa. Conservation and agro-ecological imperatives require that such diverse natural communities should be maintained and may benefit crop protection through limiting domination of pest species. Ecologically based rodent-management alternatives to rodenticides are urgently required and one such method (community trapping) is herein advocated. Aims To provide baseline information on rodent and shrew communities in agro-ecosystems in three African countries and to demonstrate efficacy of ecologically based rodent management (EBRM) in Africa (e.g. community household trapping). Methods Removal-trapping in a variety of agro-ecological habitats provided accurate small-mammal species lists. Intensive kill-trapping by rural agricultural communities was carried out experimentally where the efforts of communities were scientifically monitored by kill-trapping to measure impact on rodent numbers and the levels of post-harvest damage to stored grains. Key results Our study revealed a high diversity of endemic species in agricultural habitats in Tanzania and Namibia (but not Swaziland) and the existence of undescribed and possibly rare species, some of which may be at risk of extinction from unchecked habitat transformation for agriculture. Treatment-control studies showed that communities in three African countries could effectively reduce pest rodent populations and rodent damage by intensive trapping on a daily basis in and around the community. Conclusions Community trapping reduced pest rodent populations and damage to stored grains. Unlike the use of indiscriminate rodenticide, this practice is expected to have a negligible effect on beneficial non-target rodent and shrew species. Implications Ecologically based rodent management approaches such as community trapping will conserve beneficial non-pest rodent communities and ultimately improve crop protection.

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