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Showing papers by "Wolfgang Wagner published in 1994"


Journal ArticleDOI
TL;DR: In this paper, the phase boundary between the solid phase (ice) and the fluid phase (liquid and gas) of ordinary (light) water substance in pressure-temperature coordinates is defined.
Abstract: In order to define the phase boundary between the solid phase (ice) and the fluid phase (liquid and gas) of ordinary (light) water substance in pressure‐temperature coordinates, correlation equations for the pressure along the melting curve of the various modifications of ice as well as for the pressure along the sublimation curve are presented. The five equations for the melting pressure of the ice phases, ice I, ice III, ice V, ice VI, and ice VII, which only contain one to three fitted coefficients, cover the pressure range from the ‘‘normal’’ triple point to 20000 MPa. In this entire range the equations represent the selected measurements of the melting pressure within their experimental uncertainty. The 2‐coefficient equation for the sublimation pressure covers the temperature range from 190 K to the triple point (273.16 K). The equations correspond to the new International Temperature Scale of 1990 (ITS‐90). All these equations form the basis of the revised release on the pressure along the melting and sublimation curves of ordinary water substance. A verbatium copy of this release is presented in the Appendix of this paper. §

283 citations



Journal ArticleDOI
TL;DR: In this paper, it is argued that the structure of investigations often follows a causally explanatory design despite explicit statements to the contrary by the researchers, and that the tendency to introduce a causal relationship between representation and behaviour is due to misplacing folk-beliefs.
Abstract: This paper argues that social representations cannot be used as independent variables in causal explanations of social behaviour. It is shown that the structure of investigations often follows a causally explanatory design despite explicit statements to the contrary by the researchers. This fact is analyzed with three investigations. It is argued that verbal data used to assess the contents of a representation as independent variable are logically equivalent to data obtained from the “dependent” overt behaviour. Therefore these two kinds of data must be seen as two illustrations of the same representational contents. The researchers’preference for using verbal data to assess the independent variable and the tendency to introduce a causal relationship between representation and behaviour is shown to result from misplacing folk-beliefs. Folk-beliefs about intentional causality, it is shown, pertain to the same level as other beliefs about the world on the part of the subjects. Hence they are part of the folk-representation itself and must be treated as such; their use in scientific accounts of the belief-action relationship is not implied by data on rational belief systems. It is suggested to conceptualize social representations as integral units of beliefs and action which may be used to explain causally subsequent contingent social events. The function of folk-beliefs in intentional causality for the self-concept of rational people and for social accountability is discussed.

42 citations


Journal ArticleDOI
TL;DR: It is concluded that the proposed SEP recording technique allows independent assessment of spinal cord and brain stem activity and is superior to the conventional neck-scalp derivation technique, in which important information may be concealed or even lost due to the overlap of the brain stem P14 and spinal cord N13 potentials.
Abstract: The results of intraoperative monitoring of median nerve somatosensory evoked potentials (SEP's) were evaluated in 75 neurosurgical patients in order to assess the role of differential derivation of brain stem (P14) and spinal cord (N13) wave activity. These components were compared with the conventionally recorded neck potential ("N13") that reflects overlap of P14 and N13. The spinal cord N13 wave was recorded from the posterior to anterior lower aspect of the neck and the brain stem P14 wave from the midfrontal scalp to the nasopharynx; both derivations enabled isolated low-artifact recording of these components. In 18.7% of patients, moderate to major latency and/or amplitude shifts of N13 or P14 were found that were masked in conventional neck-scalp recordings of "N13". There was a 6.7% false-negative rate in this series. Using a neck-scalp derivation alone, a 14.7% false-negative rate would have resulted and an isolated worsening of the P14 component (with stable neck potential) in six cases would have been overlooked. It is concluded that the proposed SEP recording technique allows independent assessment of spinal cord and brain stem activity. It is, therefore, superior to the conventional neck-scalp derivation technique, in which important information may be concealed or even lost due to the overlap of the brain stem P14 and spinal cord N13 potentials.

27 citations



Journal ArticleDOI
TL;DR: In this paper, a class of stochastic systems of particles with variable weights is studied and the corresponding empirical measures are shown to converge to the solution of the spatially homogeneous Boltzmann equation.
Abstract: A class of stochastic systems of particles with variable weights is studied.The corresponding empirical measures are shown to converge to the solution of the spatially homogeneous Boltzmann equation. In a certain sense, this class of stochastic processes generalizes the “Kac master process”

6 citations


Journal ArticleDOI
TL;DR: In this article, the class of random discrete velocity models is extended and an approximation procedure for sequences of random measures is studied such that momentum and energy are preserved, and the theorem concerning convergence to an approximate Boltzmann equation is generalized to the extended class of models.
Abstract: The class of random discrete velocity models is extended. An approximation procedure for sequences of random measures is studied such that momentum and energy are preserved. The theorem concerning convergence to an approximate Boltzmann equation is generalized to the extended class of models.

3 citations


Journal ArticleDOI
TL;DR: In this article, the structure of these thin films were investigated by scanning electron microscopy (SEM) and X-ray diffractometry (XRD) and the effects of crystallinity, morphology and Si-concentration of the deposits were examinated in some detail.
Abstract: Silicon Carbide (SiC) and Silicon Carbide with free Silicon [SiC(Si)] thin films were prepared by chemical vapor deposition (CVD) using an CH3SiCl3-H2-Ar gas mixture at temperatures of 1173 to 1323 K. The structure of these films were investigated by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The effects of crystallinity, morphology and Si-concentration of the deposits were examinated in some detail.

3 citations


Journal Article
TL;DR: In this paper, the authors used low-dose radiotherapy in the treatment of hyperplastic callus formation in osteogenesis imperfecta type IV (Lobstein) under megavoltage conditions.
Abstract: PURPOSE Osteogenesis imperfecta is a rare hereditary disease of connective tissue with a genetic defect in collagen synthesis. In osteogenesis imperfecta hyperplastic heterotopic ossification can be induced by hyperplastic callus formation caused by trauma or operation. Heterotopic ossifications can be found in numerous benign diseases. The successful use of low dose radiotherapy in the treatment of heterotopic ossifications is well-known from the literature. PATIENTS AND METHODS We treated two children (a 13-year-old girl and a ten-year-old boy) with heterotopic ossifications of the lower extremities in osteogenesis imperfecta type IV (Lobstein) with a low dose irradiation (10 x 1 Gy, respectively 6 x 1 Gy) under megavoltage conditions. RESULTS After radiotherapy the children were painfree and the hyperplastic callus was considerably reduced. The previously immobilized patients could partly be mobilized. Thereby it could be contributed to the rehabilitation of the patients. New hyperplastic callus formation was not observed in the irradiated areas so far. CONCLUSION Analogous to the successful radiation of heterotopic ossifications in other benign diseases radiation therapy seems to be a successful treatment of hyperplastic callus formation in osteogenesis imperfecta. Despite the late risks of radiotherapy radiation treatment of benign diseases in children might be indicated.

2 citations