The electronic structure of organometallic complexes of the f elements XXVIII: Interpretation of the optical and magnetochemical data of a cyclohexylisocyanide adduct derived from Tris(η-cyclopentadienyl)samarium(III)

The absorption spectrum of Cp₃Sm·CNC₆H₁₁ has been measured at room temperature and at low temperatures in a hydrocarbon glass and in a KBr pellet. Electron paramagnetic resonance and magnetic susceptibility measurements are also reported in this paper. The observed optical bands were assigned on the basis of calculations which assumed that the crystal field parameters of the samarium complex were the same as for the previously analyzed Cp₃Pr·CNC₆H₁₃. The parameters of an empirical Hamiltonian were fitted to the energies of 39 levels to give an r.m.s. deviation of 21 cm⁻. On the basis of the wavefunctions of the crystal field ground state obtained from the fit, the ground state g values and the temperature-dependent magnetic susceptibility were calculated and compared with the experimental values.     

Korrosionsverhalten von Plasma- Heißdraht-Auftrag-Schweißungen. Teil I: Beständigkeit von auftraggeschweißten Nickelbasislegierungen gegen Loch- und interkristalline Korrosion

The corrosion properties of Plasma-Hot-Wire-Surfacing Part one: resistance of Nickel-base-alloy claddings against pitting and intergranular attack This paper describes measurements at claddings of nickel-based-alloys C 276, C 4 and C 22 on the St 52-3 steel substrat produced by Plasma-Hot-Wire-Surfacing (PHS). The correct heat control during the welding process is a crucial factor for the preparation of nearly precipitate-free claddings. For this reason it was necessary to optimize all the process data. The claddings itself as well as the rolled reference material (both of nearly the same chemical composition) were examined by means of metallografical and microanalytical techniques. Corrosion measurements show, that the composite materials exhibit high resistance both against pitting and intergranular corrosion and comparable to the properties of the rolled reference material. This was shown by determination of the critical pitting temperature in quinary salt solution, by electrochemical techniques in acidic chloride solution and by investigation in iron-(III)-sulfate-sulphuric acid solution.     

Electrochemical properties of anodic gold oxide layers—I: Potentiostatic oxide growth and double layer capacity

The potentiostatic growth of gold oxide layers was investigated at pH = 0, 2, and 6.2 in the potential range 1.4 V ? ? ? 2.3 V (vs hess) and for polarization times between 10^?4 and 10³ s. At ? < 2.0 V the growth of monomolecular oxide layers (oxide 1) with a thickness up to 10 Å was observed. This process takes place according to a high field mechanism. In this range, the double layer capacity decreases with increasing thickness d. With increasing ? there is a continuous change of oxide growth.At ? > 2.0 V a potential dependent linear growth law is observed with the formation of thick layers (oxide 2) up to 600 Å or more. In this range, further peaks arise in the cathodic charging curves, and the double layer capacity becomes independent of d.It follows that on the monomolecular boundary layer (oxide 1) the bulk oxide 2 is formed, which has a good ionic and electronic conductivity. Hence, the potential drop is small in oxide 2, but large in oxide 1. Even at high potentials the rate-determining step is the field dependent ionic migration in oxide 1.     

Expression profiles of effector proteins SopB, SopD1, SopE1, and AvrA differ with systemic, enteric, and epidemic strains of Salmonella enterica

The presence and expression of sopB, sopD1, sopE1, and avrA genes encoding virulence associated effector proteins were studied comparatively in 405 Salmonella enterica strains. They belong to different serovars and clonal types (genotypes, phage types) and originated from different clinical (systemic infection, focal enteritis, enterocolitis) and epidemic sources (epidemics, sporadic cases). The sopB and sopD1 determinants were commonly prevalent, but sopE1 and avrA genes only in 55% and 80%, respectively. A correlation of this pattern of absence and presence of the respective genes to the epidemic and clinical origin could not be detected. In contrast, the expression of the respective genes appeared differently: SopB and SopE1 proteins are well produced, but SopD1 and AvrA proteins only rarely under the applied standard culture conditions. However, using a range of different environmental signals (temperature, pH, cations, etc.) some of the S. enterica nonproducer strains (e. g., S. Agona, S. Bovismorbificans, S. Virchow, etc.) begin to produce AvrA and SopD1. They turned now into an expression profile which was found typically for the epidemic strains of S. Typhimurium and S. Enteritidis. Also S. enterica strains from systemic infections could be characterized by their strong SopB and SopE1 expression while SopD1 and AvrA proteins were missing. Although it is premature to outline generally a correlation of these expression profiles and the clinical and epidemiological potency of Salmonellae, the reported results allow a first understanding how a fine tuning of their virulence will take place.     

Form und Intensität des Termitenangriffes an Hölzern verschiedener Struktur und Rohdichte Erste Mitteilung: Prüfungen an getrenntem Früh und Spätholz

Zusammenfassung An getrenntem Frühholz und Sp?tholz der Holzarten Kiefer, Fichte und Stieleiche wurden Fra?zwangsversuche mit der BodentermiteReticulitermes lucifugus Rossi durchgeführt. Es wurde beobachtet, da? die Termiten beim Holzangriff vornehmlich Radialfl?chen bevorzungen und in tangentialer Richtung weiterfressen. Der Holzabbau von Frühholz und Sp?tholz nimmt mit ansteigender Rohdichte ab.

---

The way and intensity of termite attack on wood of different structure and density—Part I: Tests with separated spring: and summerwood

Summary Separated samples of springwood and summerwood of the species Scots pine, spruce and pedunculate oak were exposed to the attack of the soil-termite Reticulitermes lucifugus Rossi. When termites attack wood they mainly prefer radial sections and are going foreward in tangential direction. The portion of destroyed spring- and summerwood decreases when density increases.

     

Stabilizing and destabilizing effects of drug-excipient interactions in spray-dried,freeze-dried,and granulated Sennae fructus extracts

Abstract

The objective of this study was to compare spray-dried and freeze-dried extracts of Sennae fructus regarding the stability of the sennosides. Therefore, the influence of the addition of maltodextrin (MD) not only before the drying processes but also during fluidized bed granulation was investigated. Analysis of the hygroscopicities, the simultaneous TGA-DSC-MS data, and the influence of storage revealed that spray-dried extracts are more stable than freeze-dried extracts. The addition of MD led to an even better stability of the extracts. Lower amounts of MD are sufficient if applied onto the surface of the native extract during fluidized bed granulation.     

Tuning the colour of white polymer light emitting diodes

Colour tuning of white polymer light emitting diode (LED) light sources can be attained by various methods at various stages in the production process of the lamps and/or by the design of the active material incorporated in the LEDs. In this contribution we will describe the methods and discuss the physical background of colour tuning. Furthermore, the material design has led to polymers which are more stable during electrical stress, so that colour shift during lifetime can be excluded for white polymer LEDs.     

The European project trust—reconfigurable terminals and supporting networks

To date, research into reconfigurable mobile communications has predominantly focussed on the software radio concept, and specifically on the hardware technologies required to move physical layer processing into a programmable environment [1, 2, 3]. Although an interesting and necessary challenge, this only represents a fraction of the overall support and technology required to realise the potential of the concept. Other necessary developments include network/terminal cooperation for seamless inter-standard handoff, QoS management for software download and reconfiguration, a secure software download mechanism, terminal software and mobile radio network architecture supporting terminal reconfiguration, management for software downloads, configuration management, capability negotiation, radio resource management and spectrum allocation policies etc… This paper describes results from the EuropeanIst Trust (Transparently Reconfigurable UbiquitouS Terminal) [4] project concerning user and operator requirements, the proposed overall system environment, security issues, concerted radio resource management, and expected time frame for the development of reconfigurable terminals.