Simulating the Effects of Substrate Pre-Heating on the Final Structure of Steel Parts Built by Laser Powder Deposition

Tool steel parts built by laser powder deposition often present a heterogeneous distribution of properties caused by the complex structural transformations that occur during the deposition process. A model describing these transformations has been developed. It couples finite element heat transfer calculations with transformation kinetic theory to predict the final microstructure and properties of the material and their variation across a laser powder deposited part. Pre-heating is often used to reduce the residual stresses and the risk of thermal distortion and cracking. However, this changes the heat transfer conditions and affects the final microstructure and properties. In this work the proposed model was used to evaluate the effects of substrate preheating on the final hardness distribution. The results show that the final hardness depends considerably on the initial temperature of the substrate.Mechanical Engineerin

Targeting of anionic membrane species by lanthanide(III) complexes: towards improved MRI contrast agents for apoptosis

No abstract available

Building analytical three-field cosmological models

A difficult task to deal with is the analytical treatment of models composed by three real scalar fields, once their equations of motion are in general coupled and hard to be integrated. In order to overcome this problem we introduce a methodology to construct three-field models based on the so-called "extension method". The fundamental idea of the procedure is to combine three one-field systems in a non-trivial way, to construct an effective three scalar field model. An interesting scenario where the method can be implemented is within inflationary models, where the Einstein-Hilbert Lagrangian is coupled with the scalar field Lagrangian. We exemplify how a new model constructed from our method can lead to non-trivial behaviors for cosmological parameters.Comment: 11 pages, and 3 figures, updated version published in EPJ

Desempenho econômico das unidades familiares de produção com abundância de terra e trabalho em Capitão Poço, Pará.

bitstream/item/63045/1/Oriental-Doc40.pd

Dinâmica do investimento em trabalho nas unidades agrícolas familiares com restrição de terra e abundância de trabalho, em Capitão Poço, Pará.

bitstream/item/63214/1/Oriental-Doc47.pd

O investimento como fundamento de maximização da eficiência reprodutiva das unidades familiares com restrição de terra e trabalho, em Capitão Poço, Pará.

bitstream/item/57391/1/CPATU-Doc137.pd

Eficiência econômica das unidades agrícolas familiares com restrição de terra e abundância de trabalho em Capitão Poço, Pará.

bitstream/item/63213/1/Oriental-Doc46.pd

Reprodutibilidade das unidades agrícolas familiares com abundância de terra e restrição de trabalho em Capitão Poço, Pará.

bitstream/item/63063/1/Oriental-Doc42.pd