275 research outputs found
Dislocation Kinks in Copper: Widths, Barriers, Effective Masses, and Quantum Tunneling
We calculate the widths, migration barriers, effective masses, and quantum
tunneling rates of kinks and jogs in extended screw dislocations in copper,
using an effective medium theory interatomic potential. The energy barriers and
effective masses for moving a unit jog one lattice constant are close to
typical atomic energies and masses: tunneling will be rare. The energy barriers
and effective masses for the motion of kinks are unexpectedly small due to the
spreading of the kinks over a large number of atoms. The effective masses of
the kinks are so small that quantum fluctuations will be important. We discuss
implications for quantum creep, kink--based tunneling centers, and Kondo
resonances
An agent based decentralized matching macroeconomic model
In this paper we present a macroeconomic microfounded framework with heterogeneous agents-individuals, firms, banks-which interact through a decentralized matching process presenting common features across four markets-goods, labor, credit and deposit. We study the dynamics of the model by means of computer simulation. Some macroeconomic properties emerge such as endogenous business cycles, nominal GDP growth, unemployment rate fluctuations, the Phillips curve, leverage cycles and credit constraints, bank defaults and financial instability, and the importance of government as an acyclical sector which stabilize the economy. The model highlights that even extended crises can endogenously emerge. In these cases, the system may remain trapped in a large unemployment status, without the possibility to quickly recover unless an exogenous intervention takes place
Bank Lending, Financing Constraints and SME Investment
SME investment opportunities depend on the level of financing constraints that firms face. Earlier research has mainly focused on the controversial argument that cash flow-investment correlations increase with the level of these constraints. We focus on bank loans rather than cash flow. Our results show that investment is sensitive to bank loans for unconstrained firms but not for constrained firms, and trade credit predicts investment, but only for constrained firms. We also find that unconstrained firms use bank loans to finance trade credit provided to other firms. Our results illustrate alternative mechanisms that firms employ both as borrowers and lenders (100 words)
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