Rapid urbanization is an important characteristic of African development and yet the structural transformation debate focuses on agriculture’s relative merits without also considering the benefits from urban agglomeration. As a result, African governments are often provided conflicting recommendations on the importance of rural agriculture or urban industry. We develop dynamic economy-wide mode...

Anodic particle coloumetry is used to size silver nanoparticles impacting a carbon microelectrode in a potassium chloride/citrate solution. Besides their size, their agglomeration state in solution is also investigated solely by electrochemical means and subsequent data analysis. Validation of this new approach to nanoparticle agglomeration studies is performed by comparison with the results of...

We propose a multilevel equivalent agglomeration (MEA) model in which all particles in an irregular cluster are treated as a new particle with equivalent volume, the liquid molecules wrapping the cluster and in the gaps are considered to assemble on the surface of new particle as mixing nanolayer (MNL), the thermal conductivity in MNL is assumed to satisfy exponential distribution. Theoretical ...

A preconditioned directional-implicit agglomeration algorithm is developed for solving twoand three-dimensional viscous flows on highly anisotropic unstructured meshes of mixed-element types. The multigrid smoother consists of a pre-conditioned pointor line-implicit solver which operates on lines constructed in the unstructured mesh using a weighted graph algorithm. Directional coarsening or ag...

Copper nanoparticles have been deposited on silicon surfaces by a simple galvanic displacement reaction, and rapid thermal annealing has been performed under various atmospheric conditions. In spite of the general tendency of the agglomeration of nanoparticles to lower the surface energy at elevated temperatures, our plan-view and cross-sectional transmission electron microscopy (TEM), energy d...

The purpose of this article is twofold. First, we present an alternative model of agglomeration and trade that displays the main features of the recent economic geography literature while allowing for the derivation of analytical results by means of simple algebra. Second, we show how this framework can be used to permit (i) a welfare analysis of the agglomeration process, (ii) a fullfledged fo...

This paper uses a micro data set on auxiliary establishments from 1977 to 1997 in order to investigate the determinants of headquarter agglomerations and the underlying economic base of many larger metro areas. The significance of headquarters in large urban settings is their ability to facilitate the spatial separation of their white collar activities from remote production plants. The results...

Agglomeration can be caused by asymmetric information and a locational signaling effect: The location choice of workers signals their productivity to potential employers. The cost of a signal is the cost of housing at a location. When workers’ marginal utility of housing is negatively correlated with their productivity, skill-biased technological change causes a core-periphery bifurcation where...