Halbsandwichkomplex des Chroms mit dem Trifluormethylisocyanid-Liganden

Halfsandwich Complexes of Chromium with the Trifluoromethyl Isocyanide Ligand The synthesis and properties of the halfsandwich complexes [η⁶-1,3,5-C₆H₃(CH₃)₃]Cr(CO)₂(CNCF₃), [η⁶-1,3,5-C₆H₃(CH₃)₃]Cr(CO)(CNCH₃)(CNCF₃) und [η⁶-1,3,5-C₆H₃(CH₃)₃]Cr(CNCF₃)₃ is reported. The vibrational spectroscopic data proof the strong π accepting character of the trifluoromethyl isocyanide ligand.     

Funktionalkalküle für abgeschlossene lineare Operatoren in Banachräumen

The theory of A-scalar and generalized scalar operators of Colojoara and Foias [7] is generalized to unbounded closed operators. A spectral mapping theorem is proved for the (local) spectrum. Generalized scalar operators admit a calculus for, the C-functions on the C-manifold. B(C), the C-functions onC, which are bounded with all derivatives, is an other admissible algebra. If (T) is contained in a generalized circle, characterisations as in [7] and explicit expressions for the C^m(K)- and the B^m(R)-calculus are obtained.     

Inactivation of Vaccinia Virus by Natural Sunlight and by Artificial UVB Radiation

This study determined the sensitivity of vaccinia virus, an orthopox virus commonly used as a surrogate for variola virus (etiological agent of smallpox), exposed to UVB radiation emitted by a solar simulator, or to direct natural sunlight. The data obtained indicate that: (1) the virucidal effect of natural sunlight can be mimicked adequately by an artificial light source with similar spectral characteristics in the UVB, (2) viral sensitivity to UVB or to solar radiation can be correlated with experimental data previously obtained with UVC, (3) the correlation factor between virus inactivation by solar radiation (measured at 300 ± 5 nm) and by UVC (254 nm) is between 33 and 60, and (4) the sensitivity of viruses either dry on glass surfaces or in liquid suspension is similar when in the presence of similar amounts of cellular debris and growth media. The findings reported in this study should assist in estimating the threat posed by the persistence of virus during epidemics or after an accidental or intentional release.     

Berechnung des Temperaturverlaufes in einer transpirationsgekühlten Rohrwand

Zusammenfassung Die Innenwandtemperatur eines transpirationsgekühlten Rohres, das einen Plasmabogen umgibt, kann experimentell nur mit sehr großen Schwierigkeiten bestimmt werden. Sie läßt sich jedoch aus auf einfache Weise zu messenden physikalischen Größen berechnen. Das Rechenverfahren wird erläutert und Rechenergebnisse werden diskutiert.

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Calculation of temperature distribution in a transpiration cooled tube wall

Experimental determination of the inner wall temperature of a transpiration cooled tube surrounding a plasma arc is very difficult. This temperature, however, can be calculated from simply measurable physical quantities. The method is explained and results are discussed.

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Bezeichnungen A =m-Bc _pG/2(1–p) _w - A _s Strahlungszahl - B =4P/mc _pG r _p - c _pG spez. Wärme des Gases - C =B(1+A) - C _s Strahlungszahl des schwarzen Körpers - f(r) =(B _r+1/r) - g(r) =(C–1/r ²) - m-B Massenstrom des Gases bezogen auf 1 cm Rohrlänge - P Porosität - q-A _L Wärmemenge, die pro cm Rohrlänge durch Leitung durch die Rohrwand hindurch transportiert wird - r Rohrradius - r _i Innenradius - r _a Außenradius - r _e Rohrradius, an dem alle Temperaturen bekannt sind - r _p Porenradius - t Gastemperatur - t _a Gastemperatur außerhalb des Rohres - T Rohrwandtemperatur - T _a Rohrwandtemperatur an der Außenfläche - T _i Rohrwandtemperatur an der Innenfläche - Wärmeübergangszahl - _w Wärmeleitzahl der Wand - _G Wärmeleitzahl des Gases Herrn Professor E. R. G.Eckert zur Vollendung seines 65. Lebensjahres gewidmet.     

Public understanding of science and the perception of nanotechnology: the roles of interest in science,methodological knowledge,epistemological beliefs,and beliefs about science

In this article, we report data from an online questionnaire study with 587 respondents, representative for the adult U.S. population in terms of age, gender, and level of education. The aim of this study was to assess how interest in science and knowledge as well as beliefs about science are associated with risk and benefit perceptions of nanotechnology. The findings suggest that the U.S. public is still rather unfamiliar with nanotechnology. Those who have some knowledge mainly have gotten it from TV and the Internet. The content of current media reports is perceived as fairly positive. Knowledge of scientific methods is unrelated to benefit and risk perceptions, at least when other predictors are controlled. In contrast, positive beliefs about science (e.g., its impact on economy or health) and more sophisticated epistemological beliefs about the nature of scientific knowledge are moderately linked to more positive perceptions of nanotechnology. The only exception is the perception of scientific uncertainty: This is associated with less positive evaluations. Finally, higher engagement with science is associated with higher risk perceptions. These findings show that laypersons who are engaged with science and who are aware of the inherent uncertainty of scientific evidence might perceive nanotechnology in a somewhat more differentiated way, contrary to how it is portrayed in the media today.     

On condensation mass transfer in the presence of noncondensables

An analysis is made for the influence of the moving condensate film on the mass transfer rate from the gas-vapor mixture to the condensate. The governing energy and mass conservation equations are solved using the Crank-Nicholson method. The results show that the moving condensate film may have a considerable effect on condensation mass transfer.     

Zum Einfluß der Schalenstruktur der Kerne auf die Spektren der μ-Mesonenatome

In two earlier investigations it has been shown that the discrepancy between some new measurements^{1, 2} of the spectrum of theμ-mesic Bi-atom and the calculations ofFord andWills as well as the discrepancy found by fitting the electron-scattering data from Bi to a density function of “Fermi”-type⁴, may be explained if one takes into account explicitly the charge density of the 83-rd proton in the shell-model^{5, 6}. The present paper deals with the Tl nucleus where a similar “shell structure effect” seems to occur.     

Light-Driven Catalyst-Free Access to Phthalazines: Entry to Antiviral Model Drugs by Merging Domino Reactions**

We report the development of a metal-free four-step one-pot synthetic strategy to access high-value functionalized phthalazines using o-methyl benzophenones as starting compounds. Combining a light-mediated enolization of o-methyl benzophenones/Diels-Alder reaction domino process with a subsequent deprotection/aromatization domino reaction in one-pot leads to sustainable and efficient organic synthesis. The tangible advantages, i. e., absence of catalysts or additives, utilization of commercially available and/or easily accessible substrates, mild reaction conditions, simplicity, and single work-up procedure, make this combined process highly appealing for the direct construction of various 1-aryl-phthalazines. Importantly, in vitro bioactivity evaluation of these newly prepared heterocyclic compounds demonstrated a strong antiviral efficacy against major human pathogens like HCMV and SARS-CoV-2.     

Modeling of Gas Migration Through Low-Permeability Clay Rock Using Information on Pressure and Deformation from Fast Air Injection Tests

The characterization of gas migration through low-permeability clay formations has been a focus of R&D programs for radioactive waste disposal, which is also of great importance for shale gas exploration, cap-rock behavior of hydrocarbon reservoirs, and \(\hbox {CO}_{2}\) sequestration. Laboratory tests have been performed on Opalinus Clay, a Mesozoic claystone that is being investigated in Switzerland as a potential host rock for the storage of nuclear waste. The laboratory program included specific water and air injections tests, as well as oedometer and isotropic compression tests. Undisturbed core samples have been retrieved from a shallow borehole in the Mont Terri Underground Research Laboratory (URL) and from a deep borehole in northern Switzerland. For the shallow cores from Mont Terri URL, largely linear-elastic deformations associated with the gas injection test could be inferred and the change in void ratio was accounted for by the pore compressibility. The corresponding change in permeability was obtained from the results of the water tests, indicating a log-linear relation between permeability and porosity. The derived porosity change and the corresponding change in permeability were implemented in the standard TOUGH2 code, which reproduced the measured gas test results using fitted water retention data derived from laboratory measurements. Similar air injection tests performed on Opalinus Clay cores from the borehole at greater depth showed overall similar behavior, but at lower porosities, lower permeability values, and lower compressibility. These cases indicated nonlinear behavior which was implemented using an effective stress-dependent porosity change and the associated change in permeability. In addition, the anisotropy associated with the bedding planes of the clay formation was considered by assuming different properties for “soft” and “hard” layers to account for storage capacity for the injected gas prior to gas breakthrough. The computed change in the overall porosity could be compared to the measured axial deformation during the gas injection test and was used for calibration of the parameters describing the relationship between the effective stress and porosity, as well as the corresponding change in permeability and capillary pressure.