33,553 research outputs found
A novel framework for the use of workflow system in the integration of supply chain tiers
The global competition has imposed challenges to supply chain integration, mainly, during the process of obtain information to make demand management decisions. This paper proposes an integrated framework for data collection, analysis and results dissemination in the supply chain management (SCM), contributing to research and alternatives for \u201cThe Bullwhip Effect\u201d issue. In this sense, it is necessary to discuss the integration of supply chain management, Enterprise Resources Planning (ERP) functionality and others systems, to enlarge this scope to the total supply chain players. The ERP web-based tool and Workflow Systems (WS) can contribute to solve issues related to supply chain management. Starting from a detailed analysis of the research background regarding current SCM definitions and integration problems, Information Technology and Communication (ITC) development and WS in order to map and ensure flow fluency; the paper proposes a model to increase the overall integrations and an application in a case study for supporting the decisions that are aligned with the company\u2019s strategic objectives. This paper is divided in: research background; proposed model of the SC integration; case study, conclusions and future research
Magnetization profile for impurities in graphene nanoribbons
The magnetic properties of graphene-related materials and in particular the
spin-polarised edge states predicted for pristine graphene nanoribbons (GNRs)
with certain edge geometries have received much attention recently due to a
range of possible technological applications. However, the magnetic properties
of pristine GNRs are not predicted to be particularly robust in the presence of
edge disorder. In this work, we examine the magnetic properties of GNRs doped
with transition-metal atoms using a combination of mean-field Hubbard and
Density Functional Theory techniques. The effect of impurity location on the
magnetic moment of such dopants in GNRs is investigated for the two principal
GNR edge geometries - armchair and zigzag. Moment profiles are calculated
across the width of the ribbon for both substitutional and adsorbed impurities
and regular features are observed for zigzag-edged GNRs in particular. Unlike
the case of edge-state induced magnetisation, the moments of magnetic
impurities embedded in GNRs are found to be particularly stable in the presence
of edge disorder. Our results suggest that the magnetic properties of
transition-metal doped GNRs are far more robust than those with moments arising
intrinsically due to edge geometry.Comment: submitte
Continuous and discontinuous absorbing-state phase transitions on Voronoi-Delaunay random lattices
We study absorbing-state phase transitions in two-dimensional
Voronoi-Delaunay (VD) random lattices with quenched coordination disorder.
Quenched randomness usually changes the criticality and destroys discontinuous
transitions in low-dimensional nonequilibrium systems. We performed extensive
simulations of the Ziff-Gulari-Barshad (ZGB) model, and verified that the VD
disorder does not change the nature of its discontinuous transition. Our
results corroborate recent findings of Barghatti and Vojta [Phys. Rev. Lett.
{\bf 113}, 120602 (2014)] stating the irrelevance of topological disorder in a
class of random lattices that includes VD and raise the interesting possibility
that disorder in nonequilibrium APT may, under certain conditions, be
irrelevant for the phase coexistence. We also verify that the VD disorder is
irrelevant for the critical behavior of models belonging to the directed
percolation and Manna universality classes.Comment: 7 pages, 6 figure
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bitstream/item/142982/1/2018.pd
Impurity segregation in graphene nanoribbons
The electronic properties of low-dimensional materials can be engineered by
doping, but in the case of graphene nanoribbons (GNR) the proximity of two
symmetry-breaking edges introduces an additional dependence on the location of
an impurity across the width of the ribbon. This introduces energetically
favorable locations for impurities, leading to a degree of spatial segregation
in the impurity concentration. We develop a simple model to calculate the
change in energy of a GNR system with an arbitrary impurity as that impurity is
moved across the ribbon and validate its findings by comparison with ab initio
calculations. Although our results agree with previous works predicting the
dominance of edge disorder in GNR, we argue that the distribution of adsorbed
impurities across a ribbon may be controllable by external factors, namely an
applied electric field. We propose that this control over impurity segregation
may allow manipulation and fine-tuning of the magnetic and transport properties
of GNRs.Comment: 5 pages, 4 figures, submitte
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