The biological and chemical properties of functionally active proteins are dependent upon their three-dimensional molecular structures. Insight into the role of the gene-determined primary sequence of a protein molecule in providing a thermodynamically stable tertiary structure with biological activity was obtained through the classical experiments of White, Anfinsen, and their colleagues on the renaturation of reductively denatured ribonuclease A (1–3). In these and subsequent investigations, it has been demonstrated that the acquisition of functional tertiary structures in relatively simple, single-chained protein molecules can occur spontaneously as a result of the inherent thermodynamics of the system; i.e., interactions among the linear array of amino acid residues and the molecular environment.

Using the Sommerfeld method we find the Green's function of a mixed boundary-value problem for the Laplace equation in a half-space with circular boundary conditions. A wide class of stationary problems in heat conduction, electrostatics, and elasticity theory reduce to the solution of this problem.

Through the analysis of the magneto-reflectance of the 1s excitons arising from the Γ₆-Γ₈ band pair, the effect of the $$ \overrightarrow K $$ -linear term on the exciton states with exchange splitting between the J=1 and J=2 states has been clearly demonstrated. The existence of the electron hole exchange splitting is also shown in the case of (D^oX) bound exciton complex through the analysis of the magneto-luminescence spectrum including the two-electron transitions.

Since investigations into materials handling and layout situations are usually concerned with industrial processes or movement of materials in connection therewith, and since work study is a widely accepted set of tools for analysing industrial problems, it will come as no surprise to find that it forms the basis of methodical investigations in these areas.

Security control is one of the emerging concepts of recent years in power systems monitoring and operation. This paper presents a method based on pattern recognition techniques, where all the on-line calculations are replaced by the only evaluation of the sign of a separating function depending on measurements directly obtained from the power system. A large number of off-line network studies are to be run to compute this separating function.

Experimental spectra for Ge obtained using synchrotron radiation (hν ≤ 23 eV) are compared with predictions of a direct-transition theory which includes anisotropic transmission through the (111) cleaved surface. The direct transition-determined structure plot for Ge (peak binding energies as a function of photon energy), as well as other spectral features, are fit well up to hν ≳ 23 eV using a d-nonlocal pseudopotential model. We demonstrate that this model provides a proper description of conduction band topology far (~ 1 Ryd) above the gap. Our ability to obtain these results shows that features predicted by an anisotropic, direct opticaltransition model can determine one-electron energy bands over a wide energy range even in the presence of short escape depths and surface-associated emission.

Zusammenfassung

Wie BREDSDORFF, IDORN, KJAER, PLUM und POULSEN (1962)in einem zusammenfassenden Symposiumsbericht aufzeigten, wurden Untersuchungen über die Alkali-Kieselsäurereaktion in vielen Ländern durchgeführt. Besonders eingehend befaßten sich amerikanische, dänische, englische und australische Autoren mit diesem Problem der Betontechnologie.

In an industrial power station for the chemical industry DDC has been used for the first time in Germany in power plants.

The processing of the control circuits is based on the processing of analog and digital measured values organized in lists. These lists are completed by means of the keyboard of a data display. In the same way, the control circuits are structured by means of the data display and control parameters given to the control algorithms.

A three-term control algorithm has been selected as it ensures optimum control results under consideration of the storage size and the computer time required.

High flexibility is reached due to the fact that analog and digital values which are obtained by means of freely programmable functions in the computer can be processed like analog and digital values of the hardware. Thus, the sequential control can act on the reference value control and the control circuit structure. In addition, the controller parameters may depend on selectable process variables by means of software analog functions.

26 out of the 38 control circuits of the steam generator are working unter DDC. 45 control functions including cascade control and feed-forward control with time behaviour are operating under DDC. In addition, 21 control circuits have been equipped with simple analog back-up controllers.

The conditions for changing-over from “DDC” to “back-up” and “hand” have been determined in co-operation with the user under consideration of safety and economical aspects.

The DDC-position-algorithm consists of the three-term control algorithm and the balancing algorithm. The latter is used for the control circuits operating under “back up” or “hand” to facilitate the smooth transition to the control algorithm at any time.

Finally, the experience gained during the commissioning of direct digital control circuits and the operational results obtained up to now are described.