Promoting competition in the fertilizer industry in Africa: A global and local approach

2018 ◽  
Author(s):  
International Food Policy Research Institute (IFPRI)
Keyword(s):  
Local Approach ◽  
Fertilizer Industry ◽  
Global And Local

Finite and infinite structures of rational matrices: a local approach

2015 ◽  
Vol 30 ◽  
Author(s):  
A. Amparan ◽  
S. Marcaida ◽  
Ion Zaballa
Keyword(s):  
Local Structure ◽  
Complete System ◽  
Irreducible Polynomial ◽  
Rational Functions ◽  
Rational Matrix ◽  
Local Approach ◽  
Elementary Divisors ◽  
Ring Of Polynomials ◽  
Principal Ideal Domains ◽  
Global And Local

The structure of a rational matrix is given by its Smith-McMillan invariants. Some properties of the Smith-McMillan invariants of rational matrices with elements in different principal ideal domains are presented: In the ring of polynomials in one indeterminate (global structure), in the local ring at an irreducible polynomial (local structure), and in the ring of proper rational functions (infinite structure). Furthermore, the change of the finite (global and local) and infinite structures is studied when performing a Mobius transformation on a rational matrix. The results are applied to define an equivalence relation in the set of polynomial matrices, with no restriction on size, for which a complete system of invariants are the finite and infinite elementary divisors.

Construction of the Design Space of Single-Loop Change-Point Mechanisms

2004 ◽  
Author(s):  
Craig P. Lusk ◽  
Larry L. Howell
Keyword(s):  
Change Point ◽  
Design Space ◽  
Local Approach ◽  
Single Loop ◽  
Inversion Operator ◽  
Global And Local ◽  
Insight Into

Change-point mechanisms are shown to be significant in the design of surface micromachined MEMS. The design space of change-point mechanisms is derived for an arbitrary single loop change-point mechanism using a global and local approach. A function on the design space, the mechanism’s length, is constructed for fourbars. An inversion operator, a mapping from the design space to the design space, is also constructed for fourbars. The method for constructing the function and the operator is shown to be capable of extension to single loop change-point mechanisms with five or more links. The results give insight into design possibilities and limitations of change-point mechanisms.

scholarly journals Global and local aspects of entrainment in temporal plumes

2016 ◽  
Vol 812 ◽  
pp. 222-250 ◽  
Author(s):  
Dominik Krug ◽  
Daniel Chung ◽  
Jimmy Philip ◽  
Ivan Marusic
Keyword(s):  
Numerical Simulation ◽  
Numerical Data ◽  
Small Scale ◽  
Local Approach ◽  
Local Propagation ◽  
Entrainment Coefficient ◽  
Baroclinic Torque ◽  
Entrainment Process ◽  
Set Up ◽  
Global And Local

To date, the understanding of the role buoyancy plays in the entrainment process in unstable configurations such as turbulent plumes remains incomplete. Towards addressing this question, we set up a flow in which a plume evolves in time instead of space. We demonstrate that the temporal problem is equivalent to a spatial plume in a strong coflow and address in detail how the temporal plume can be realized via direct numerical simulation. Using numerical data of plume simulations up to $Re_{\unicode[STIX]{x1D706}}\approx 100$, we show that the entrainment coefficient can be determined consistently using a global entrainment analysis in an integral framework as well as via a local approach. The latter is based on a study of the local propagation of the turbulent/non-turbulent interface relative to the fluid. Locally, this process is dominated by small-scale diffusion which is amplified by interface convolutions such that the total entrained flux is independent of viscosity. Further, we identify a direct buoyancy contribution to entrainment by baroclinic torque, which accounts for 8 %–12 % of the entrained flux locally, comparable to the 15 % buoyancy contribution at the integral level. It appears that the baroclinic torque is a mechanism that might explain higher values of the entrainment coefficient in spatial plumes compared with jets.

scholarly journals Testing the Validity of the ‘Local’ and ‘Global’ GKLS Master Equations on an Exactly Solvable Model

2017 ◽  
Vol 24 (04) ◽  
pp. 1740010 ◽  
Author(s):  
J. Onam González ◽  
Luis A. Correa ◽  
Giorgio Nocerino ◽  
José P. Palao ◽  
Daniel Alonso ◽  
...  
Keyword(s):  
Master Equation ◽  
Open Quantum Systems ◽  
Solvable Model ◽  
Exact Result ◽  
Quantum Systems ◽  
Local Approach ◽  
Weakly Coupled ◽  
Exactly Solvable ◽  
Global And Local ◽  
Secular Approximation

When deriving a master equation for a multipartite weakly-interacting open quantum systems, dissipation is often addressed locally on each component, i.e. ignoring the coherent couplings, which are later added ‘by hand’. Although simple, the resulting local master equation (LME) is known to be thermodynamically inconsistent. Otherwise, one may always obtain a consistent global master equation (GME) by working on the energy basis of the full interacting Hamiltonian. Here, we consider a two-node ‘quantum wire’ connected to two heat baths. The stationary solution of the LME and GME are obtained and benchmarked against the exact result. Importantly, in our model, the validity of the GME is constrained by the underlying secular approximation. Whenever this breaks down (for resonant weakly-coupled nodes), we observe that the LME, in spite of being thermodynamically flawed: (a) predicts the correct steady state, (b) yields with the exact asymptotic heat currents, and (c) reliably reflects the correlations between the nodes. In contrast, the GME fails at all three tasks. Nonetheless, as the inter-node coupling grows, the LME breaks down whilst the GME becomes correct. Hence, the global and local approach may be viewed as complementary tools, best suited to different parameter regimes.

scholarly journals A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parSPartition Assembly

Biochemistry ◽  
2011 ◽  
Vol 50 (11) ◽  
pp. 1799-1807 ◽  
Author(s):  
Barnali N. Chaudhuri ◽  
Sayan Gupta ◽  
Volker S. Urban ◽  
Mark R. Chance ◽  
Rhijuta D’Mello ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Local Approach ◽  
Global And Local

A Global-Local Strategy for the Elastoplastic Analysis of Complex Metallic Structures via Component-Wise Approach

2018 ◽  
Author(s):  
Erasmo Carrera ◽  
Ibrahim Kaleel ◽  
Manish Nagaraj ◽  
Marco Petrolo
Keyword(s):  
Finite Element ◽  
Global Analysis ◽  
Local Analysis ◽  
Local Approach ◽  
Element Analysis ◽  
Lagrange Polynomials ◽  
Finite Element Software ◽  
Carrera Unified Formulation ◽  
Von Mises ◽  
Global And Local

A global-local approach has been developed for the elasto-plastic analysis of thin-walled metal structures, which interfaces between commercial finite element software and advanced structural theories based on the Carrera Unified Formulation (CUF). The structure is modeled in CUF using the Component-Wise approach where Lagrange polynomials enhance the cross-section kinematics of the beam element. The von Mises constitutive model with isotropic work hardening is used to describe the material nonlinearity. Two types of the global-local approach have been discussed: (1) elastoplasticity is considered in both global and local analyses, and (2) a linear global analysis is followed by a nonlinear local analysis. It is shown that the second version maintains the accuracy of the solution for cases where the plastic zone is localized within the structure. The described approach results in a significant reduction in the computational size of the problem, compared to standard 3D finite element analysis.

Comparison of Global and Local Approaches to Predicting Warm Pre-Stress Effect on Cleavage Fracture of Ferritic Steels

2004 ◽  
Vol 261-263 ◽  
pp. 69-74 ◽  
Author(s):  
Saeid Hadidi-Moud ◽  
A. Mirzaee-Sisan ◽  
Christopher E. Truman ◽  
David John Smith
Keyword(s):  
Fracture Toughness ◽  
Cleavage Fracture ◽  
Type Model ◽  
Ferritic Steels ◽  
Stress Effect ◽  
Loading History ◽  
Global Approach ◽  
Local Approach ◽  
Global And Local ◽  
Weibull Stress

Potentially both global and local approaches may be used to predicting the effect of loading history on cleavage fracture toughness distribution of ferritic steels. In this paper the dramatic increase in the apparent lower shelf fracture toughness of A533B steel following warm pre-stressing (WPS) has been predicted using these approaches. Extensive experimental evidence suggesting significant enhancement in fracture toughness of ferritic steels within the lower shelf temperatures following WPS are used to verify and compare the applicability and the extent of validity of the models. The global approach is based on the distribution of toughness data described by Wallin statistical model in conjunction with the Chell model for WPS effect. The local approach on the other hand is a Beremin type model that uses the Weibull stress to predict the WPS effect. Weibull stresses would essentially reflect the WPS effect on redistribution of stress-state around the crack tip. Predictions for apparent toughness using the two approaches are discussed in the light of the suggestion that residual stresses are the main cause of the enhancement, at least for the material and geometry used in this study.

Sunspot Groups as Tracers of Sub-Surface Processes

2000 ◽  
Vol 179 ◽  
pp. 155-160
Author(s):  
M. H. Gokhale
Keyword(s):  
Magnetic Flux ◽  
Indian Institute ◽  
Surface Processes ◽  
The Sun ◽  
Global And Local ◽  
Sunspot Groups

AbstractData on sunspot groups have been quite useful for obtaining clues to several processes on global and local scales within the sun which lead to emergence of toroidal magnetic flux above the sun’s surface. I present here a report on such studies carried out at Indian Institute of Astrophysics during the last decade or so.

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