Thirty years after Harrison and Saeed: Does the medium make the message?

In 1977, Harrison and Saeed published what became the classic study of personal advertisements. They found that women tended to offer youth and attractiveness, while seeking financial security or wealth. Men, in turn, sought youth and attractiveness, while offering financial security. The purpose of the current study was to determine if changes in the medium used for personal ads (Internet versus print) has had an impact on stated preferences in mate selection. Our results duplicated the Harrison and Saeed (1977) findings, suggesting that neither the medium, nor the societal changes of the last 30 years, have had any effect on mate selection. In a supplementary analysis of women in the 50–69 age group, however, we found that these women were less willing to date older men, preferring younger partners.     

Die neue DAfStb‐Richtlinie “Vorbeugende Maßnahmen gegen schädigende Alkalireaktion im Beton”

The new DAfStb‐Guideline “Preventive Measures against detrimental Alkali‐Reaction in Concrete (Alkali‐Guideline)” In 2002 the German Committee for Structural Concrete decided to revise the Alkali‐Guideline. The motivation for the revision may be summarised as follows: – further developments in the german concrete technology – damage cases in concrete pavements – development of new rapid test methods – further specification of alkali reactive aggregates The contribution gives a detailed overview of the main amendments in the new Guideline and illustrates the background behind the key regulations.     

Ein orthotropes Werkstoffgesetz für Folien

An orthotropic material law for foils. Foils are characterized by an orthotropic load carrying behaviour, which results from the manufacturing process. Normally this orthotropic behaviour is not considered in structural analysis. In the following a theory is described, which allows the determination of any plain stress situation and the test is shown to verify the theory. This is a necessary assumption for a more precise prediction to the load carrying behaviour in membrane structures made of foils.     

Quantitative X-ray microanalysis of hydrogen peroxide within plant cells

Using quantitative X-ray microanalysis in combination with CeCl3-based cytochemical staining of hydrogen peroxide (H2O2) we have developed a new solution for quantification of H2O2 at the subcellular level. Quantitative X-ray microanalysis of plastic-embedded leaves of Populus euphratica Oliv. showed that the obtained cerium precipitates by CeCl3 staining were the mixture of cerium perhydroxides and cerium phosphate, in which the fractions of CePO4 were: (1) 52-74% in cell walls of fresh leaf segments, and (2) 34-70% in the cytoplasm in 10 mM H2O2-treated leaf segments that were previously freeze-dried. Taking the concentration of cerium phosphate as staining background, we reached the cellular concentration of cerium perhydroxides and the corresponding concentration of H2O2. Results showed that H2O2 was present in the cytoplasm of rehydrated leaf segments (29-58 mM), but in fresh leaves, H2O2 was observed in the walls of all measured cell types (17-74 mM).     

Polyaluminum chloride with high Al30 content as removal agent for arsenic-contaminated well water

Polyaluminum chloride (PACl) is a well-established coagulant in water treatment with high removal efficiency for arsenic. A high content of Al₃₀ nanoclusters in PACl improves the removal efficiency over broader dosage and pH range. In this study we tested PACl with 75% Al₃₀ nanoclusters (PACl_Al30) for the treatment of arsenic-contaminated well water by laboratory batch experiments and field application in the geothermal area of Chalkidiki, Greece, and in the Pannonian Basin, Romania. The treatment efficiency was studied as a function of dosage and the nanoclusters’ protonation degree. Acid-base titration revealed increasing deprotonation of PACl_Al30 from pH 4.7 to the point of zero charge at pH 6.7. The most efficient removal of As(III) and As(V) coincided with optimal aggregation of the Al nanoclusters at pH 7-8, a common pH range for groundwater. The application of PACl_Al30 with an Al_tot concentration of 1-5 mM in laboratory batch experiments successfully lowered dissolved As(V) concentrations from 20 to 230 μg/L to less than 5 μg/L. Field tests confirmed laboratory results, and showed that the WHO threshold value of 10 μg/L was only slightly exceeded (10.8 μg/L) at initial concentrations as high as 2300 μg/L As(V). However, As(III) removal was less efficient (<40%), therefore oxidation will be crucial before coagulation with PACl_Al30. The presence of silica in the well water improved As(III) removal by typically 10%. This study revealed that the Al₃₀ nanoclusters are most efficient for the removal of As(V) from water resources at near-neutral pH.