Time-optimal control of hyperbolic systems with deviating arguments

In this paper the time-optimal control problem for distributed hyperbolic systems in which time delays appear in the integral form both in the state equations and in the boundary conditions is considered. The particular properties of the optimal control are discussed.     

Prediction of the Mechanical Properties of P91 Steel by Means of Magneto-acoustic Emission and Acoustic Birefringence

The paper describes an application of non-destructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic deformation in order to achieve the material with an increasing strain level up to 10%. Subsequently, non-destructive and destructive tests were performed. Magnetic methods based on measurements of magnetoacoustic emission and magnetic hysteresis loop changes as well as the ultrasonic method based on acoustic birefringence measurements, were applied. Finally, the static tensile tests were carried out in order to evaluate the mechanical parameters. It is shown that some relationships between the selected parameters coming from the non-destructive and destructive tests may be formulated.     

PMS—A program to make learning Pascal easier

One of the essential tasks in the teaching of a programming language is the introduction of the main constructs of the language—the syntax and semantics of statements, control, procedures, file handling, and so on. Most teachers present this topic by simulating the operation of the computer on the chalkboard by manual tracing of the execution of sample demonstration programs. Upon closer inspection it becomes clear that this task could be performed by the computer itself. A program implementing this idea would help the teacher in the class and the student (who could use the computer to repeat the instructor's performance at any time and on any problem of his choice) both in the class and in study. This article describes a collection of programs called PMS that performs exactly this function for the teaching of Pascal.PMS is organized as a collection of “mimlanguages” each of which demonstrates, and allows the user to experiment with, a certain category of Pascal features using a particular screen representation. Each of the subsystems contains a syntax-driven, screen-oriented translator associated with an interpreter that controls execution and the appropriate screen representation. This modular structure of PMS reflects the fact that programming is always taught by presenting certain essentially disjoint language features individually. In addition to their logical independence, these disjoint concepts also require different graphical approaches for their visual representation and this reinforces the need for modularization of the package.PMS is written in Pascal and runs on several computers including the IBM PC.     

Serum lipids during parenteral nutrition with a 10% lipid emulsion with reduced phopholipid emulsifier content in premature infants

Whether dithiocarbamate-Fe(II) complexes used in the electron spin resonance (ESR) studies are specific for the detection of NO was investigated. It was found that the typical ESR signals of dithiocarbamate-Fe(II)-NO spin adducts appeared in the interaction of N-methyl-D-glucaminedithiocarbamate (MGD)-, bis(hydroxyethyl) dithiocarbamate (HED)- and diethyldithiocarbamate (DED)-Fe(II) complexes with the NO-derived nitrogen oxides, nitrogen dioxide (NO2) and nitrite ion (NO2-) in a prolonged incubation. Under the conditions of prolonged incubation, appearance of the ESR signals of the dithiocarbamate-Fe(II)-NO spin adducts may indicate the presence of not only NO but NO2 and NO2-.     

Immunogold localization of the 97-kD antigen of linear IgA bullous dermatosis (LABD) detected with patients'' sera

The classification of linear IgA bullous dermatosis in the group of subepidermal blistering diseases is still a matter of controversy. This situation is due partly to the considerable clinical heterogeneity of the disease but also results from the difficulties in characterization and localization of the specific basement membrane zone antigen(s) recognized by immunoglobulin (Ig)A antibodies. In the present study, we have combined the Western blot detection of circulating autoantibodies with an ultrastructural immunogold labeling of human skin antigens using the same patients' sera. Our results, obtained with a short series of sera showing exclusive IgA class reactivity with the epidermal portion of salt-split skin, indicate that the antibodies recognizing the 97-kD antigen on immunoblot bind to the hemidesmosomal plaques of basal keratinocytes and the adjacent lamina lucida. These homogeneous laboratory results remain in striking contrast to the heterogeneity of clinical pictures in the patients studied, suggesting a participation of complementary, possibly not humoral, phenomena in the pathogenesis of linear IgA bullous dermatosis.     

The effect of aminophylline on pentagastrin-induced secretion and motor activity of totally isolated canine stomach perfused extracorporeally

Totally isolated canine stomachs, perfused extracorporeally with homologous blood of living oxygenerator-dogs, were used for the study of gastric secretion. Aminophylline and pentagastrin were infused into the gastric arterial system separately or combined. Aminophylline, infused alone, did not stimulate gastric secretion. However when aminophylline was administered during the infusion of pentagastrin, it significantly augmented the action of this peptide on gastric acid secretion. Aminophylline did not alter myoelectrical and mechanical response to pentagastrin nor did it affect the myoelectrical activity of the nonstimulated stomach. Gastric arterial perfusion pressure and gastric peripheral resistance were reduced during infusion of aminophylline alone or in combination with pentagastrin.