Willem A. Smit

Civilian–military co-operation strategies in developing new technologies

Dual use technology has been advocated as the solution for the twin problem of maintaining a high tech defence technology base and improving economic competitiveness. The concept of dual use technology turns out to be rather imprecise representing a multitude of different meanings. This paper focuses on one important aspect, notably the co-operation between civilian and military actors in developing a new technology, by analysing the evolution of a socio-technical network related to the development of an advanced battery in The Netherlands. n nThe analytical framework used for interpreting the empirical case builds on theories of socio-technical networks and on two previous and complementary analyses in Research Policy on dual use technology. Our analysis of the dynamics underlying the evolution of the ‘battery network’ shows how the emerging notion of the battery’s duality became a window of opportunity for a co-operation strategy of either joint or concurrent development of the battery for both civilian and military applications. The interactions within the evolving network are steered by the search for expertise and funding. n nIn view of the difficulties of realising civilian–military integrated joint development projects, the establishment of ‘dual capacity networks’ is suggested as part of a possible strategy towards an integrated civilian–military technology and industrial base.

The battle between standards: TCP/IP Vs OSI victory through path dependency or by quality?

Between the end of the 1970s and 1994 a fierce competition existed between two possible standards, TCP/IP and OSI, to solve the problem of interoperability of computer networks. Around 1994 it became evident that TCP/IP and not OSI had become the dominant standard. We specifically deal with the question whether the current dominance of the TCP/IP standard is the result of third degree path dependency or of choices based on assessments of it being technical-economically superior to the OSI standard and protocols.

The Knight shift in liquid alkali alloys

Abstract The Knight shifts of the 39 K, 87 Rb and 133 Cs nuclei in binary alkali alloys are determined as a function of the composition of the alloys. A linear relation between the Knight shift and the atomic concentration of either of the components has been found. A survey of the results obtained by different authors is given. No reasonable explanation has been found for the linear concentration dependence of the Knight shift. Qualitatively the results can be explained in terms of ionization potentials. A quantitative discussion has been given on the basis of scattering theory using phase shifts according to Blatt and to Alfred and Van Ostenburg. It provides no more than order of magnitude agreement with the experiments.

COEXISTENCE OF FERROMAGNETISM AND SUPERCONDUCTIVITY IN A SUPERCONDUCTING ALLOY

Abstract A model for a superconducting alloy doped with magnetic impurities is solved exactly. The model consists of a combination of the BCS model and the Zener s-d exchange-interaction model. Its behaviour appears to be strongly dependent on the impurity concentration and the coupling parameters belonging to the BCS model and the s-d exchange-interaction model. At very low temperatures the system is always a ferromagnet or a superconductor. Coexistence of superconductivity and ferromagnetism is only possible at finite temperatures for certain values of the coupling parameters and the concentration of magnetic impurities. The transitions from the mixed state to the superconducting and to the magnetic state do not need to be continuous, i.e., second order.

EXACT SOLUTION OF ZENERS S-D EXCHANGE INTERACTION MODEL

Abstract The exact solution for the Zener s-d exchange-interaction model is presented. The system exhibits a second-order phase transition. It appears that the critical temperature T c is independent of the sign of the s-d exchange interaction. Under the assumption that the conduction band has a constant density of states, an explicit expression for T c is derived in terms of the conduction-band width D , the concentration c of the magnetic impurity spins and the strength J of the s-d exchange coupling. For the case of an antiferromagnetic exchange coupling it is found that the directions of the magnetization of the conduction electrons and of the impurity spins depend on the magnetic field strength.

Structural investigation of hydrogen bonds in deuterated pentaerythritol by nuclear magnetic resonance

A single-crystal of pentaerythritol with deuterium substituted on the hydroxylic hydrogen positions was investigated by means of nuclear magnetic resonance. The quadrupole splittings of the deuterium magnetic resonance lines were measured as a function of the orientation of the external field with respect to the crystal axes. The electric field gradient tensors at the positions of the deuterium nuclei were evaluated and compared with the results obtained by Chiba in other hydrogen-bonded systems. The results provide evidence for a configuration obtained by taking the oxygen and carbon parameters from Shiono, Cruickshank & Cox (Acta Cryst. (1958), 11, 389) and the hydrogen parameters from Hvoslef (Acta Cryst. (1958), 11, 383).

A framework for a sociology of assessing and intervening in technology development

New Technology may have unintended and even negative impacts. This article explores some new approaches in policy analysis of socio-technical networks aimed at improving foresight for technological advances.

The anisotropic i-d interaction ferromagnet in equivalent neighbour version

Abstract A model consisting of the anisotropic i-d interaction ferromagnet in equivalent neighbour version and the anisotropic Heisenberg magnet in equivalent neighbour version is solved exactly in the thermodynamic limit.

COEXISTENCE OF SUPERCONDUCTIVITY AND MAGNETISM

Abstract A model consisting of the B.C.S.-Hamiltonian and Zeners s-d exchange interaction is solved rigorously in the thermodynamic limit. Coexistence of superconductivity and magnetism is only possible for an impurity spin concentration smaller than a half at T ≠ 0.

Numerical results in the Kondo problem

Abstract A numerically solvable Kondo model is formulated. It is shown that for certain cases the limit T → 0 does not yield the correct ground state.