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In comparison to the adsorption of hydrocarbons, the adsorption of mercury on activated carbons reveals many unexpected results. Both physisorptive and chemisorptive mechanisms play a role even in the adsorption on nonimpregnated activated carbons. In this work, the adsorption of Hg0 from a N2 carrier gas stream is studied on three commercial adsorbents. Single and cumulative breakthrough curves are measured in a fixed bed at temperatures of 25–100 °C and mercury concentrations of 50–1000 μg m–3. Isosteric heats of adsorption are calculated from the measured adsorption isotherms. Here, adsorption enthalpies in the range of 50% of the vaporization enthalpy are determined. In addition, desorption experiments are conducted to distinguish the contributions of physisorption and chemisorption. A dynamic simulation of experimental breakthrough curves yields diffusion coefficients, which are discussed with respect to the concentration and temperature dependence of diffusion mechanisms in mercury physisorption.

The UV spectroscopic properties of the principal inorganic ionic species in natural waters were investigated at 25 °C in the wavelength range 195 to 280 nm. All absorbing species were identified and the corresponding molar absorptivities were determined experimentally. No cations were found to influence the UV spectrum. Relatively high molar absorptivities were observed for iodide, bromide and nitrate. The UV spectra of natural waters were calculated using the molar absorptivities and compared with observed signals from synthetic samples. This enabled the dominant components to be determined. Both bromide and nitrate have significant influence on the UV spectrum of natural waters. The study results can be used to predict the UV spectra of ionic solutions and thus evaluate the suitability of UV spectroscopy for given measurement projects.

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Für die Modellierung der Versuche mit reaktiven Mischungen wurde aufgrund dieser Ergebnisse die Modellvariante offene Verdampfung gewählt.Abb. 8 zeigt ein typisches Ergebnis einer Modellvorhersage, die mit dem oben beschriebenen Stufenmodell für die partielle reaktive Verdampfung einer Formaldehyd/ Wasser-Mischung erzielt wurde. Die Übereinstimmung zwischen den Messwerten und den Modellvorhersagen ist nicht nur für die pauschalen Zusammensetzungen des Kopf-und Sumpfprodukts gut, sondern auch für die besonders wichtige Speziesverteilung im Sumpfprodukt.

Although the transversus abdominis plane (TAP) block has an established role in providing postoperative analgesia following caesarean section, the technique is not widely used by obstetric anaesthetists. The conventional TAP block is associated with significant technical difficulties and risk of peritoneal, hollow viscus and organ perforation. We report a much simpler technique in which the obstetric surgeon, during open surgery, is able to introduce the TAP block via an intra-abdominal approach, which is technically easier and also obviates the risks associated with the conventional TAP procedure. We believe our technique may be easier, safer and equally effective.Keywords Caesarean section, local anaesthetic, postoperative analgesia, rescue analgesia, transversus abdominis plane block.

This paper presents adsorption isotherms and desorption data of halogenated ethers (desflurane, isoflurane, and sevoflurane), which are used as inhalation anesthetics, and aliphatic ethers (diethyl ether and methyl propyl ether) from a nitrogen carrier gas stream. The isotherms were measured at 25 °C and 1 bar. Desorption was analyzed at temperatures between 25 and 250 °C. Zeolites with different structure and aluminum content as well as activated carbons with different pore size distributions were used as adsorbents. The analysis of the adsorption isotherms and the desorption data focuses on the interactions between adsorptive molecules and adsorbents' surfaces. We discuss the specific influence of the molecular structure and polarity of the adsorptives as well as of the pore structure and surface chemistry of the adsorbents.