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Mit der Einfuhrung des Eurocodes 3 und der DIN EN 1090-2 ist es in Deutschland unter anderem in Bezug auf die Ausfuhrung von geschraubten Verbindungen in Stahltragwerken zu grosen Verwirrungen gekommen. Diese beruhen im Wesentlichen – aber nicht nur – auf der Frage: Welches Vorspannkraftniveau darf bei welchem Verbindungstyp mit welchem Anziehverfahren angesetzt werden? Wo die Frage nach dem richtigen Anziehverfahren relativ schnell geklart ist, da dieses uber den Nationalen Anhang zur Bemessungsnorm fur Stahlbauanschlusse, der DIN EN 1993-1-8/NA, eindeutig an die Hohe des Vorspannkraftniveaus gekoppelt ist, fuhrt die Frage nach dem “richtigen” Vorspannkraftniveau sowohl beim Tragwerksplaner als auch bei der ausfuhrenden Stahlbaufirma immer wieder zu grosen Diskussionen, dass das in DIN EN 1090-2 angebotene Mindestvorspannkraftniveau Fp,C in Deutschland nur mit dem in der nationalen Praxis zwar durchaus bekannten, aber absolut unublichen Kombinierten Vorspannverfahren aufgebracht werden darf. Alternativ dazu wurde in DIN EN 1993-1-8/NA das niedrigere “alte” deutsche Regelvorspannkraftniveau Fp,C* mit Ausfuhrungsregeln zum Anziehen mittels des modifizierten Drehmoment-Vorspannverfahrens wieder definiert. Weitere praxisrelevante Fragestellungen betreffen exemplarisch das Anziehen von nicht vorgespannten Schraubverbindungen und den Einsatz von nicht CE-gekennzeichneten Komponenten einer CE-gekennzeichneten Schraubengarnitur. Im Rahmen des vorliegenden Beitrags werden diese und weitere Fragestellungen zum Anziehen von geschraubten Verbindungen im Stahlbau zusammenfassend beantwortet. Tightening of bolted connections according to Eurocode 3 and DIN EN 1090-2. With the introduction of Eurocode 3 and DIN EN 1090-2, great confusions arise in Germany regarding the execution of bolted connections in steel structures. This is based essentially – but not exclusively – on the question: which preload level may be applied in which connection type with which tightening procedure? Where the question of the “correct” tightening procedure is resolved relatively quickly, since this is clearly linked via DIN EN 1993-1-8 / NA at the height of the applied preload level, yields the question of the “correct” preload level for both the structural engineer and the executive steel construction company to major discussions since DIN EN 1090-2 offers the minimum preloading force Fp,C which is allowed to be applied in Germany only by the – although known, but absolutely unusual – combined method. Alternatively, the lower “old” German preloading force Fp,C* is defined in DIN EN 1993-1-8 / NA with execution rules for the modified torque method. Other practical questions relate to the tightening of non-preloaded bolts and the use of non CE-marked components of a CE-marked bolt assembly. As part of this paper, these and other issues for the tightening of bolted connections in steel structures are answered.

This article critically examines institutional versions of cosmopolitan democracy and institutional ideas of global federalism. Assuming global institutions to be as they are designed in conceptions of cosmopolitan democracy, the paper addresses a feasibility question: (To what degree) would such global democratic structures meet normative standards of democratic accountability. As there is no global democracy existing, the argumentation makes a detour, first investigating the experiences of the most advanced project of cosmopolitan democracy – the European Union – and then, second extrapolating from persistent, structural democratic deficits in the EU to the feasibility of global democracy. Compared to national arenas, the EU faces a gradual deficit in democratic capacities and the global reality of cosmopolitan democracy would be –even compared to the EU – a downgraded democracy as well. The main findings are: Vertical accountability is either more ineffective or more inegalitarian or both. Neither unitary nor federal systems should be seen as a plausible solution for the threat of ‘Verselbstandigung’ caused by multilevel politics. And nationally segmented public spheres will not promote a similar type of politicised discourses around ‘common’ global issues.

In the previous decade, the European Commission has promoted direct citizen involvement in European Union (EU) affairs via institutions such as deliberative polls, citizen conferences, online consultations or citizens' initiatives. Do these instruments foster EU democratisation? In this article, the Commission's participatory turn is re-constructed. Against the yardstick of a democracy theoretical framework, two participatory instruments (European Citizens' Consultations and the Commission's online consultations) are assessed. Both instruments are seriously flawed: the ECC cannot resolve the trade-off between demanding and egalitarian participation, and remains almost unrecognised outside the forum (bridging problem). Online consultations suffer both from a lack of active participation and of the symbolic accountability of the Commission to the contributions of ordinary citizens.

The temperature sensitive mutant strain E. coli C600 T44 and its parental strain E. coli C600 were lysogenized with λ+ and different λCI phage mutants and induced for vegetative phage development by different inducing agents such as heat, UV irradiation, nutritional shift up, and supplementation of the culture medium with adenine. The effectivity of inducing agents expressed by two measured parameters (induction effect and latent period) is discussed in terms of comparison between the bacterial and phage mutants used. Following conclusions can be drawn: Both the inducible fraction and the efficiency of UV irradiation and nutritional shift up as inducing agents are enhanced in T44 in comparison with the parent strain C600. The repressers coded for by the very UV sensitive λCI prophages λt U37 and λinds exhibit an enhanced affinity with respect to λ+ repressors to the effector molecules accumulated after inducing treatment with UV light, heat, nutritional shift up, and adenine supplementation. The experimental data reported suggest that there is a regulatory circuit controlling the concentration of the effector molecules. The T44 mutation seems to affect the properties of this regulatory circuit resulting in alteration of both the accumulation kinetics and the maximal concentration of effector molecules. Furthermore, the T44 mutation renders the feedback loop of this control circuit temperature sensitive. From the experimental results it is concluded that more than one kind of stereospecific effector molecules are able to influence the repressor activity. The ratio of the concentrations of these molecules and their accumulation kinetics depend on the kind of inducing agent. Heating yields a fast accumulation kinetics while UV irradiation and adenine supplementation result in a slow one. Therefore, adenine does not interact directly with phage repressor molecules but with some elements of the regulatory circuit altered by the T44 mutation.

Der Deutsche Ausschus fur Stahlbau (DASt) veranstaltet regelmasig ein Kolloquium zu aktuellen Forschungsthemen aus dem Bereich des Stahlbaus. Die Veranstaltung ist vergleichbar mit einem PhD-Symposium, im Rahmen dessen jungen Nachwuchswissenschaftlern die Moglichkeit geboten wird, ihre laufenden Forschungsaktivitaten und Ergebnisse zu prasentieren und zur Diskussion zu stellen. Das Kolloquium richtet sich hauptsachlich an Ingenieure aus der Praxis, Personen aus den Verwaltungen und andere junge Ingenieure aus der Forschung mit dem Ziel, uber den gegenwartigen Stand der Stahlbauforschung in Deutschland zu informieren. Das 15. DASt-Forschungskolloquium fand am 1. und 2. April 2004 an der Universitat Stuttgart statt. Im Rahmen des Kolloquiums war es erstmals moglich, drei der 20 Vortragenden mit Preisen fur die besten Prasentationen auszuzeichnen. Dieser Beitrag schliest, neben einem allgemeinen Uberblick uber das 15. DASt-Forschungskolloquium, eine kurze Zusammenfassung der drei ausgezeichneten Prasentationen ein. 15. DASt-research-colloquium steel construction. The German association of steel construction (DASt) regularly holds a colloquium on actual research topics in the field of steel construction. This event is a kind of a PhD symposium where young researchers have the possibility to present and discuss their actual research activities and results. The colloquium mainly addresses to practical engineers, people of administrations and other young research engineers with the aim to inform about the current stage of steel research in Germany. The 15. DASt-research-colloquium was held at the University of Stuttgart on 1. and 2. April. Within this colloquium it was the first time possible to award three of the 20 speakers with prices for their best presentations. This contribution thus includes, beside an general overwiew on the 15. DASt-research-colloquium a short summary of each of the three awarded presentations.

Am Meeresgrund und vereinzelt in Dauerfrostböden liegt eine schier unerschöpfliche Energiequelle verborgen: Methanhydrat — eine Einschlussverbindung aus Wasser und Methan, in der das Methangas in Eiskäfigen eingeschlossen wird. Makroskopisch nimmt Methanhydrat eine eisähnliche Gestalt an. In reiner Form ist es schneeweiß und zersetzt sich bei Raumtemperatur und Atmosphärendruck. Dabei wird Methangas frei, dessen Menge ausreicht, um eine dauerhafte Flamme bis zur vollständigen Zersetzung eines Gashydratbrockens zu erzeugen — daher rührt auch der Name „Brennendes Eis”. Die mikroskopische Struktur und Dynamik von Methanhydrat waren bislang noch weitgehend unerforscht. Neutronenstreuexperimente ergaben jetzt erste Einsichten.

Kleine Molekule, Seitengruppen oder polyatomare Ionen konnen im Kristall rotieren. Bei hochsymmetrischen Gruppen wie z. B. CH3, CH4, NH3 und NH 4 + werden bei der Rotation von einer Gleichgewichtslage in eine andere identische Teilchen miteinander vertauscht. Der Name Rotation ist schlecht gewahlt, weil im Laufe dieses Austauschs das Molekul durchaus deformiert werden darf und weil auserdem in der Anfangs- und Endlage das Molekul nicht unbedingt in der hochsymmetrischen Konfiguration eines gleichseitigen Dreiecks oder regularen Tetraeders vorliegen mus. Es ware viel besser, fur das Ergebnis dieser Bewegung das Wort Permutation, nicht aber Rotation zu wahlen. Die durch Permutation von identischen Teilchen auseinander hervorgehenden Gleichgewichtslagen sind vollstandig aquivalent. Dies zeigt die Abb. 1 am Beispiel einer Methylgruppe.

A newly developed macro flow planktometer is described for measuring plankton organisms with a size of 100-2,000 microns by the flow principle in time-saving and noncontact fashion. Based on the method of changes in electric resistance (Coulter principle), the device allows determination of the body volume of living organisms in their natural medium (fresh or seawater) at a measuring rate of up to 50 organisms per second. Simultaneous, laser-excited fluorescence measurement permits quantitative detection of fluorescent substances within the organisms. Controlled by the multiparametric measurement, video images of organisms of particular interest can be taken in the flow chamber using a stroboscopic imaging system. Valuable morphological information on the material under test is thus available in addition to the analytical measurement. Data acquisition and imaging, the total system control, and the fast data evaluation are performed with an IBM-AT compatible computer using an extensive software package. The easy-to-handle desktop unit can be used both in land laboratories and on ships. The modular structure of the system permits any desired combination of individual components to adapt it to various requirements. The operability of this new measuring system is demonstrated by several applications.

A series of hydrodynamic simulations is presented, related to laser compression of matter. In particular, low entropy compression of hydrogen is studied in order to reach the metallic phase transition. Anomalous hydrodynamic phenomena like shock splitting and rarefaction shocks occuring in the neighbourhood of the phase transition are investigated for a special configuration.

17 alpha-Methyltestosterone and the corresponding 1(2)-dehydrocompound (Dianabol) are efficient inducers of the 4-en-3-oxosteroid: (acceptor)-1-en-oxidoreductase from Nocardia opaca. After a lag period of 4 hours the enzyme activity increases rapidly. During the induction the steroids are completely metabolized causing a drastical drop of specific enzyme activity. Using a fixed induction time the optimal steroid concentration and the temperature characteristic were found out. The influence of the concentration of the steroid water suspension on the induction effect is discussed to be dependent on the velocity of the dissolving of the steroid particles. Chloramphenicol and streptomycin are powerful inhibitors of the induction process.

Unvernetzte PVC-g-Styren-co-Methylmethacrylat-Polymere lassen sich in Dimethylformamid mit 90% Propfausbeute in Gegenwart eines Chrom(II)-acetat/Morpholinocyclohexen-Initiatorsystems synthetisieren. Es werden Propfgrad und Propfausbeute in Abhangigkeit von der Temperatur sowie der Monomer- und Initiatorkonzentration untersucht. Uncrosslinked PVC-g-styrene-co-methyl methacrylate is synthesized in dimethylformamide with 90 per cent graft efficiency by initiation the grafting with a chromous acetate/1-morpholinocyclohexene system. Grafting and graft efficiency are studied as a function of temperature and of the concentration of initiator and grafting monomers.

Besides the established T-cell property of producing gamma interferon (IFN-gamma), murine T cells additionally possess the ability to produce IFN-alpha and IFN-beta when appropriate inducers such as 10-carboxymethyl-9-acridanone (CMA) or Newcastle disease virus (NDV) are used. Interleukin 2 (IL-2)-dependent murine T-cell lines, but not purified resting splenic T cells, responded to CMA and NDV with production of IFN-alpha, beta. The IFN production by these T cells was not restricted to a special subset, since T cells expressing the Lyt 1+2- and the Lyt 1-2+ phenotype responded to these inducers with IFN production. After prolonged passaging of the T-cell lines in IL-2-containing medium, the ability to respond to CMA with production of antiviral activity was sustained longer than the ability for concanavalin A-induced IFN-gamma production. Whereas the NDV-induced T-cell supernates contained both IFN-alpha and IFN-beta, the induction with CMA resulted exclusively in the synthesis of IFN-beta by the T-cell lines.

Indomethacin was tested for its ability to augment the cytotoxic capacity of cultured bone marrow-derived macrophages (M phi) against P815 and YAC-1 tumor cells. M phi were obtained from the bone marrow of C57BL/6 mice precultured for 10-14 days and were virtually 100 percent pure. By addition of indomethacin these cells were activated to kill tumor cells in a 4-h and 18-h Cr-release assay. Since indomethacin is a potent inhibitor of the cyclooxygenase system, M phi were treated with prostaglandin E2. This treatment partially reversed indomethacin-induced cytotoxicity. Addition of other cyclooxygenase inhibitors such as acetyl-salicylic-acid, diclofenac or carprofen also induced cytotoxicity in bone marrow-derived M phi. In all experiments we failed to detect any production of interferon. Addition of anti-interferon did not alter the cytolytic capacities demonstrating that endogenously induced interferon was not relevant in this mechanism. Our data show that cyclooxygenase inhibitors induce cytolytic activity of murine M phi not only against a M phi target but also against YAC-1 cells usually considered to be targets for natural killer cells.

The transformation of cholesterol to cholest-4-ene-3-one has been investigated in the presence of toluene and carbontetrachloride using cells of Nocardia erythropolis (IMET 7185) immobilized by different methods. The adsorption on DEAE-cellulose has been observed to be the most effective method. The stability of immobilized cells relating to cholesteroloxydase activity, transformation capacity, and the influence of water have been investigated.

The kinetics of plasma and breath elimination of aminopyrine after 14C-aminopyrine given orally were studied using an open one-compartment model and first order rates of elimination. The study comprises eight healthy volunteers and two groups with histologically verified chronic liver diseases (cirrhosis, n= 12, and chronic aggressive hepatitis, n= 12). Elimination rates from plasma and breath were significantly reduced in the group with cirrhosis, but only so in chronic aggressive hepatitis when they were expressed relative to each other. Monomethylaminopyrine was eliminated more rapidly compared to aminopyrine, and the rate of formaldehyde formation was positively correlated to the excretion rate of CO2 (r= 0.53, P

The degradation of cholesterol side chain was studied by immobilized cells of Nocardia erythropolis in the presence of an inhibitor of the microbial steroid-skeleton-degradation. Different immobilized preparations such as DEAE-cellulose adsorbates, ionic cross-linked polymer gels, i.e., Al/Coalginates and polyacrylates, respectively, and polyethylene maleic acid anhydride supports have shown a high transformation activity yielding the C22- and C19-degradation products. No side chain degradation activity could be observed after immobilization of the cells in polyacrylamide gel under usual conditions caused by the toxic effect of the acrylamide monomer on the Nocardia cells.

The current–voltage behaviour of ion implanted silicon electrodes in HF electrolyte is investigated. The electrolytic reverse current, i.e. the reaction rate of the minority carrier limited reactions is found to increase. The current increase depends on the implanted dose and layer stripping. Reason for the increased reverse current can be referred to radiation damage acting as generation centres for minority carriers. Measurement of the electrolytic reverse current can be used for determination of damage profiles. Layer stripping is carried out by anodic dissolution in the same electrolyte. The sensitivity of this new method for characterizing ion implanted silicon layers lies at 1011 to 1012 atoms cm−2. Das Stromdichte–Potential-Verhalten ionenimplantierter Siliziumelektroden im HF-Elektrolyten wird untersucht. Es wird eine Erhohung des elektrolytischen Sperrstromes festgestellt, d. h. die Geschwindigkeit der durch die Minoritatsladungstragerkonzentration bestimmten Reaktionen ist vergrosert. Die Stromerhohung ist abhangig von der implantierten Dosis und der abgetragenen Schichtdicke. Als Ursache der Stromerhohung werden Strahlenschaden festgestellt, die als Generationszentren fur Minoritatsladungstrager wirken. Die Messung des elektrolytischen Sperrstromes kann zur Bestimmung von Strahlenschadenprofilen verwendet werden. Die Schichtabtragung erfolgt dabei durch anodische Auflosung im gleichen Elektrolyten. Die Empfindlichkeit dieser neuen Methode zur Charakterisierung ionenimplantierten Siliziums liegt bei 1011 bis 1012 cm−2.

The induction of the 4-ene-3-oxosteroid: (acceptor)-1-ene-oxidoreductase in Nocardia opaca has been shown to be dependent on both hydrophilic and hydrophobic structural features of the steroid molecule, i.g. the nature of the oxygen function in positions 11 and 20 and the presence of the methyl group in position 10 influence the induction of the enzyme drastically. In this connection the metabolism of the steroid inductors being degradated during the induction process has been considered.

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