[en] The authors consider experimental signatures of models with composite W/sup +-/, Z/sup 0/ and composite quarks and leptons. Properties of the composite Z/sup 0/ are discussed in detail. In addition to the W/sup +-/ and Z/sup 0/, many new composite bosons are expected to appear as distinct, narrow resonances in pp, p-bar p, ep and e-bar e interactions. It is possible that the bosons responsible for the weak interactions are composite. In this report the authors consider the experimental signatures of models of this type. Much of the analysis is model independent, however when a specific model is considered they will use the realistic example. In this model the known fermions are correctly described in terms of light bound states, and the weak interactions are the result of residual strong interactions between their constituents. (The gluons and the photon are elementary particles.) The low-energy (E << G/sub F//sup -1/2/) properties of this composite model agree with those of the standard model, but at higher energies new and different phenomena are predicted. The authors discuss how the predictions of the standard model are modified in models with composite W's and Z and analyze the new physics which can be investigated at present and future accelerators. There are three main topics: modification of mass, and production and decay properties for a composite Z/sup 0/; deviations from the standard model in e/sup +/e/sup -/ collisions below the Z mass; and predictions of a rich spectrum of new heavy particles

[en] This paper gives a presentation of the High Energy Physics research activities in which the experimental group of the National Technical University in Athens is involved. The research activities of the group are concentrated mainly on two experiments: The photoproduction experiment NA14 at the SPS accelerator and the DELPHI experiment at LEP

[en] The purpose of this paper is to describe a method for identifying such stable excited quarks via their time of flight. If these states are heavier than 50 GeV or so then it is only at hadron-hadron colliders that they could be produced in the near future. The authors believe that the search described in this paper would be sensitive to stable decouplet quarks with masses up to 200 GeV or so. Of course, the search would also be sensitive to any other kind of charged, massive, stable particle, as long as the production cross section is comparable to those shown in a figure. The main experimental challenge is to make the time of flight counters attain a reasonably good time resolution in the high rate environment implied by the luminosities envisioned here

[en] The development of high pressure technology which has allowed the synthesis of diamond and cubic boron nitride has also resulted in the production of a new and exciting range of ultra hard ceramic-type materials. These materials, polycrystalline diamond and cubic boron nitride composites, offer distinct advantages over their single crystal counterparts and hold the promise of a fascinating future in all areas connected with material removal and other specialist usages

[en] The primary event in the action of cholera toxin on the isolated chick intestinal epithelial cell is its interaction with the cell membrane. This involves a large number (17 million per cell) of high affinity binding sites which belong to a single class. Binding of biologically active ¹²⁵I-labeled toxin is rapid, temperature-dependent, reversible, and saturable over a wide range of concentrations and includes only a small contribution from nonspecific sites. A characteristic lag phase of 10 min occurs following the complete binding of toxin before any increase in cellular cAMP levels can be detected in the isolated cells. The response (elevation of cellular cAMP) of the enterocytes to cholera toxin is linear with time for 40-50 min and causes a six- to eight-fold increase over control levels at steady stae. cAMP and agents that increase cAMP production inhibit Cl^--independent Na⁺ influx into the isolated enterocytes whereas chlorporomazine (CPZ) which completely abolishes toxin-induced elevation of cAMP both reverses and prevents the cAMP-mediated inhibition of Na⁺ entry. Correlation between cellular cAMP levels and the magnitude of Na⁺ influx into the enterocytes provides evidence for a cAMP-mediated control of intestinal Na⁺ uptake, which may represent the mechanistic basis for the antiabsorptive effect of CT and Na⁺ during induction of intestinal secretion. The effect of cAMP on Na⁺ but no Cl^- influx in our villus cell preparation can be partially explained in terms of a cAMP-regulated Na⁺/H⁺ neutral exchange system

[en] The repair stopper is used to seal off heat exchanger pipes, which have been damaged in operation. A force and cleaning stopper part forms one unit. The two operations of remote cleaning and forcing the stopper in can be combined in one operation. The cleaning stopper part does the cleaning at the pressure weld position when the repair stopper is inserted. Directly after cleaning, the pressure welding of the forced stopper part to the steam raising unit heating pipe is done. (DG)

[en] In this review it is briefly described what has been done so far on electronic transitions taking place during an atom-diatom exchange collision, applying quantum mechanical techniques. The field is relatively new - it was started only around 1975 - and this is clearly perceived while considering the various achievements in the field. One should expect much future activity in this field. However, since the simultaneous treatment of the two processes involved - exchange and electronic transitions - is rather complicated, it is anticipated that they will be treated using simplified models only. These might include the Distorted Wave Born approximation or the Infinite Order Sudden Aproximation which were found to be quite useful in the studies of single surface problems. (orig.)

[en] The informative ability of the laterally quantified lung perfusion scintigraph for the clarification of the operability of a histologically proven bronchial carcinoma was tested in a retrospective study on 148 patients with the following results: 1. Perfusion scintigraphs and tumor stage, respectively tumor size, correlate very well with one another in determining that a lymph node infection cannot be preoperatively clarified. 2. The scintigraph gives indications of the extent of resectioning to be expected. 3. Technical and prognostic inoperability can be predicted exactly, however, not the operability, because the method of choice for the detection of organ and lymph node metastases is now as before mediastinoscopy. (TRV)

[en] The hypophyseal hormone TSH is a sensitive as well as specific screening parameter for the early recognition of connate primary hypothyroidism, since because of the autonomy of the fetal thyroid regulation system it indicates itself already in newborns by a clearly increased serum level. The methodical development of a radioimmunological determination of TSH in whole blood by means of commercial reagents as a screening method is described and compared to other procedures. The best time for the carrying out of the screening (here the 5th day of life) is discussed. From all together 3204 examinations on newborns in this program a hypothyroidal metabolic condition could be diagnosed in 5 children. (TRV)

[en] The most complex physico-chemical process 'mineral formation in multicomponent system' is discussed in the sense of limiting cases. The following elementary processes are briefly treated: nucleation and formation of new phases, matter transport in one phase multicomponent system, heterogeneous reaction in multicomponent system. In many cases zero, one and two dimensional crystalline defects play an important role for the morphological and kinetical development of minerals. The role of point defect thermodynamics for the transport coefficient and transport theory of crystalline multicomponent systems is pointed out in some detail. (orig.)