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Identifies and describes the problems students have with the concept of neutralization. Analysis of over 7,500 students' answers to test questions over neutralization showed that many students understand the concept in its original meaning. Students assumed that in any neutralization reaction a neutral solution is formed, even if a weak acid or base takes part in the reaction. (Author/KR)

Victor Meyer (1848-1897) was one of the most outstanding chemist of the second half of the 19th century. He is known for his numerous papers in the field of organic chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Meyer. In addition, his research activities is briefly described, and especially the chemical reaction named after him. [ABSTRACT FROM AUTHOR]

Hans Landolt (1831-1910) was one of the important chemists of the second half of the XIX century and the first decade of the XX century. The purpose of this paper is to familiarize readers with the important events in the life of Landolt and his writing activities, in particular with his chemistry books. In addition, his research activities is briefly described, and especially the chemical reaction named after him. [ABSTRACT FROM AUTHOR]

Victor von Richter (1841-1891) was one of the important chemists of the second half of the 19th century. The purpose of this paper is to familiarize readers with the important events in the life of Richter and his writing activities, in particular with his chemistry textbooks for higher education, well-known in different countries. In addition, his research activities is briefly described, and especially the chemical reactions named after him. [ABSTRACT FROM AUTHOR]

The term "chemical reactor" appears for the first time in open literature at the end of First World War, while in Germany the term "reaction technology" was coined in the 1950s, although chemical reactions and processes have been known for thousands of years. In the early days, reactors were furnaces and pots, which specialized further over the centuries. With the Industrial Revolution many reactor types were already known, and industrialization brought an enormous innovation thrust in the field of products as well as technologies. The diversity of reactors today is almost uncomprehensive and so efforts to standardize apparatus are understandable. [ABSTRACT FROM AUTHOR]

The emergence of physical organic chemistry, which focuses on the mechanisms and structures of organic reactions and molecules using the tools of physical chemistry, was a major development in twentieth-century chemistry. It first flourished in the interwar period, in the UK and then in the US. Germany, by contrast, did not embrace the field until almost a half century later. The great success of classical organic chemistry, especially in synthesis, encouraged indifference to the new field among German chemists, as did their inductivist research philosophy, as enunciated by Walter Hückel’s ground-breaking textbook (1931). This author also resisted new concepts and representations, especially those of the American theoretician, Linus Pauling. The arrival of the Nazi regime reinforced such resistance. Postwar conditions initiated a reaction against this conservative, nationalistic attitude, especially in the American Occupation Zone. Exposure to American textbooks and visiting lecturers influenced attitudes of younger chemists. The accompanying shift towards a more explanatory, less hierarchical mode of pedagogy was consonant with larger social and political developments. [ABSTRACT FROM AUTHOR]

The emergence of physical organic chemistry, which focuses on the mechanisms and structures of organic reactions and molecules using the tools of physical chemistry, was a major development in twentieth-century chemistry. It first flourished in the interwar period, in the UK and then in the US. Germany, by contrast, did not embrace the field until almost a half century later. The great success of classical organic chemistry, especially in synthesis, encouraged indifference to the new field among German chemists, as did their inductivist research philosophy, as enunciated by Walter Hückel’s ground-breaking textbook (1931). This author also resisted new concepts and representations, especially those of the American theoretician, Linus Pauling. The arrival of the Nazi regime reinforced such resistance. Postwar conditions initiated a reaction against this conservative, nationalistic attitude, especially in the American Occupation Zone. Exposure to American textbooks and visiting lecturers influenced attitudes of younger chemists. The accompanying shift towards a more explanatory, less hierarchical mode of pedagogy was consonant with larger social and political developments. [ABSTRACT FROM AUTHOR]

Curriculum-assessment alignment is a well known foundation for good practice in educational assessment, for items' curricular validity purposes. Nowadays instruments are designed to measure pupils' competencies in one or more areas of competence. Sub-competence areas could be defined theoretically and statistical analysis of empirical data by using Rasch models could reveal if the sub-competence areas defined theoretically are belonging to the same empirical scale. As a result of unsatisfactory results of pupils to TIMSS in 2000, national educational standards were implemented in Germany and research in the area of competence assessment was started. Though, the compulsory, comprehensive content description of the material intended to be taught in class is depicted in curricula. As a result of federalism in Germany, each of the 16 federal states provides a curriculum. The aim of this exploratory study is the identification of the topics most frequent across the curricula of the 16 federal states. Consequently, curriculum analysis of the curricula for two type of schooling in Germany, for secondary level I, for each of the 16 federal states in proposed. [ABSTRACT FROM AUTHOR]

Abstract: Chemical components of fine particles (FPs; aerodynamic diameter, Dp < 2.5 μm) and ultrafine particles (UFPs; Dp < 0.1 μm) at Japanese and German roadsides were investigated during summer. The UFPs/FPs ratio for organic carbon (OC) concentrations on weekdays was 34.5% and 25.0% at Japanese and German roadsides, respectively, whereas 3.3% and 6.4% for elemental carbon (EC) concentrations, respectively. These results thus indicate a higher OC and a lower EC contribution from UFPs at the Japanese roadside than at the German roadside. In particle samples, OC2 and OC3 constituted a high proportion of UFPs, and pyrolyzed OC and EC1 were predominant among FPs of 0.1 μm < Dp < 2.5 μm. Our results showed roadside environment exist not only primary FPs and UFPs but also secondary FPs and UFPs from photochemical reactions or long-range transport. [Copyright &y& Elsevier]

The article presents a study which compares the mixing rations of N2O5 during NO3 Comp 2007 in the atmosphere simulation chamber SAPHIR in Jülich, Germany. It shows an excellent agreement between measurements using different techniques. It suggests that high aerosol loads can reduce the N2O5 inlet transmission efficiency.

Density differences are the key parameter for stratification stability. We used data from the iron-meromictic Waldsee, Germany, a lignite mine pit lake, to quantify the contribution of single solutes to water density and analyzed the density gradient. Iron meromictic lakes maintain their density gradient through chemical reactions. Hence, quantifying the contributions of separate solutes is essential for understanding the entire process. Based on solute concentrations and literature values of partial molal volumes, substance specific density contributions were quantitatively evaluated. Then, by direct measurements of the density of IHSS Waskish peat fulvic acid, we quantified the density contribution of dissolved organic carbon (DOC). While several solutes contributed to the density throughout the water column, only those substances that occurred at higher concentrations in the anoxic monimolimnion than in the oxic mixolimnion were crucial to sustaining the density difference between the two layers. In Waldsee, the density difference between monimolimnion and mixolimnion was attributed to dissolved Fe (0.23 g/L, resulting in a 45 % of the density difference due to solutes) and to the carbonate system (HCO, about 0.16 g/L and CO, 0.03 g/L) while Ca and DOC delivered only a small contribution. In summer, total density differences were dominated by temperature differences; during winter, solutes sustained meromixis. Finally, we present a complete list of specific density fractions for basically all of the density-relevant substances in fresh waters. [ABSTRACT FROM AUTHOR]

To investigate the energy, matter and reactive and non-reactive trace gas exchange between the atmosphere and a spruce forest in the German mountain region, two intensive measuring periods were conducted at the FLUXNET site DE-Bay (Waldstein-Weidenbrunnen) in September/October 2007 and June/July 2008. They were part of the project "ExchanGE processes in mountainous Regions" (EGER). Beyond a brief description of the experiment, the main focus of the paper concerns the coupling between the trunk space, the canopy and the above-canopy atmosphere. Therefore, relevant coherent structures were analyzed for different in and above canopy layers, coupling between layers was classified according to already published procedures, and gradients and fluxes of meteorological quantities as well as concentrations of non-reactive and reactive trace compounds have been sorted along the coupling classes. Only in the case of a fully coupled system, it could be shown, that fluxes measured above the canopy are related to gradients between the canopy and the above-canopy atmosphere. Temporal changes of concentration differences between top of canopy and the forest floor, particularly those of reactive trace gases (NO, NO2, O3, and HONO) could only be interpreted on the basis of the coupling stage. Consequently, only concurrent and vertically resolved measurements of micrometeorological (turbulence) quantities and fluxes (gradients) of trace compounds will lead to a better understanding of the forest-atmosphere interaction. [ABSTRACT FROM AUTHOR]

Abstract: Soil water repellency (SWR) is widely thought to be influenced by soil pH, however, few studies have systematically investigated the relationship between these variables. Specifically the hypothesis that the pH may control repellency via changes in the variable surface charge of soil material has not yet been tested. In previous work, methods for changing soil pH have also involved changes in soil moisture, but it has been argued that the potential influence of soil moisture changes needs to be eliminated before the actual relationship between pH and SWR can be isolated. The paper addresses this research gap using a new method, which enables adjustment of the pH of soils with low moisture content via the gas phase and thus involves minimal change in moisture content, allowing the response of SWR to pH changes to be evaluated. The method was applied to 14 soil samples from Germany, The Netherlands, the UK, and Australia, using the water drop penetration time (WDPT) as the indicator of SWR. Additionally, sessile drop contact angles (Θ sess ) were measured on the four samples from Germany and the titratable surface charge of these four soils was measured at selected pH values using a particle charge detector (PCD). Changes in SWR with soil pH were found to be influenced by the density and type of sites able to interact with protons at the available surfaces of organic and mineral materials in soil. The maximum SWR occurred for soil at natural pH and where the charge density was minimal. As pH increased, negative surface charge increased due to deprotonation of sites and WDPT decreased. Two types of behaviour were observed: i) a decrease in repellency with decreasing pH, probably because of a sufficient number of proton accepting surface sites with a significant amount of positive surface charge, ii) no decrease in repellency with decreasing pH in soils with insufficient proton accepting surface sites to develop significant positive surface charge. The data suggest that the availability and relative abundance of proton active sites at mineral surfaces, and those at organic functional groups influence the response of the soil samples to changes in pH. The variety of geographic origins and histories of the soils examined provides a distinction between site specific and more widely applicable soil characteristics of pH dependent SWR. [Copyright &y& Elsevier]

Abstract: Ion dynamics in arable soils are strongly affected by the chemical and biological transformations triggered by fertilizer input. Hydrogeochemical models may improve our understanding of underlying processes. Our objective was to test the ability of the hydrogeochemical model PHREEQC2 in combination with the parameter optimization program PEST to describe and predict chemical and biological processes in silty soils triggered by fertilizer application or acidification and to investigate the usefulness of different parameterization approaches. Three different experiments were carried out using undisturbed columns of two topsoils (0–25cm) from Germany (Göttingen, GO) and from the Oman (Qasha'', QA). The columns were irrigated at 10°C with 3mmday−1 for one year using 1mM HCl (HCl experiment) and two fertilizer solutions with low (0.1 to 0.9mmolL−1) and high concentrations (1.3 to 14.7mmolL−1) of N (as NH4NO3), K, Ca and Mg. In the fertilization experiments (Fert1, Fert2), the columns were alternately irrigated with the two different solutions for variable time periods. One-dimensional transport and homogenous and heterogenous reactions were calculated using PHREEQC2. The Fert1 experiment was used for calibration. The models were validated using the Fert2 and HCl experiments. The models tested were model variant m1 with no adjustable parameters, model variant m2 in which nitrate concentrations in input solutions and cation exchange capacity were optimized for Fert1, and m3 in which additionally all cation exchange coefficients and ion concentrations in the initial solution were optimized. Model variant m1 failed to predict the concentrations of several cations for both soils (modelling efficiencies (EF)≤0), since N dynamics were not considered adequately. Model variants m2 and m3 described (Fert1 treatment) and predicted (Fert2 and HCl treatment) pH, cation and NO3 − concentrations generally more accurately for both soils. For nutrient cations, EF values for prediction for GO ranged from 0.44 (K) to 0.99 (Ca), for QA from 0.21 (K) to 0.96 (Ca). After optimization, PHREEQC2 was able to predict NO3 − concentrations in both soils (EF≥0.57). Model variant m3 indicated that between 54 (QA) and 72% (GO) of the exchange sites were involved in cation exchange reactions. Our results show the importance of the inclusion of nitrogen species when modelling cation dynamics in arable soils from different climate regions. The hydrogeochemical model PHREEQC2 in combination with PEST was useful to describe and predict ion dynamics in silty soils under unsaturated conditions. [Copyright &y& Elsevier]

Three approaches towards ion track-based biosensors appear to be feasible. The development of the first one began a decade ago [Siwy, Z.; Trofin, L.; Kohl, P.; Baker, L.A.; Martin, C.R.; Trautmann, C. J. Am. Chem. Soc. 2005, 127, 5000-5001; Siwy, Z.S.; Harrell, C.C.; Heins, E.; Martin, C.R.; Schiedt, B.; Trautmann, C.; Trofin, L.; Polman, A. Presented at the 6th International Conference on Swift Heavy Ions in Matter, Aschaffenburg, Germany, May 28-31, 2005] and makes use of the concept that the presence of certain biomolecules within liquids can block the passage through narrow pores if being captured there, thus switching off the pore's electrical conductivity. The second, having been successfully tested half a year ago [Fink, D.; Klinkovich, I.; Bukelman, O.; Marks, R.S.; Fahrner, W.; Kiv, A.; Fuks, D.; Alfonta, L. Biosens. Bioelectron. 2009, 24, 2702-2706], is based on the accumulation of enzymatic reaction products within the confined volume of narrow etched ion tracks which modifies the pore's electrical conductivity. The third and most elegant, at present under development, will exploit the charge transfer from enzymes to semiconductors embedded within etched tracks, enabling the enzymes undergoing specific reactions with the biomolecules to be detected. These strategies can be realized either within carrier-free nanoporous polymeric membranes embedded in the corresponding bioliquids, or within contacted nanoporous insulating layers on semiconducting substrates, the so-called TEMPOS structures [Fink, D.; Petrov, A.; Hoppe, H.; Fahrner, W.R.; Papaleo, R.M.; Berdinsky, A.; Chandra, A.; Biswas, A.; Chadderton, L.T. Nucl. Instrum. Methods B 2004, 218, 355-361]. The latter have the advantage of exhibiting a number of peculiar electronic properties, such as the ability for logic and/or combination of input signals, tunable polarity, negative differential resistances, tunability by external parameters such as light, magnetic fields, etc. and self-pulsations, which should enable one to design intelligent autonomous biosensors. It also appears possible to let the enzymatic reactions take place on the surface of carbon nanotubes embedded within such TEMPOS structures. The advantages and disadvantages of all these approaches will be compared with each other, in respect to detection selectivity, sensitivity and accuracy, as well as sensor reproducibility, reusability and stability. [ABSTRACT FROM AUTHOR]

Abstract: After massive epidemics of bluetongue disease in 2006 and 2007, Germany has started a compulsory vaccination program against bluetongue virus serotype 8 (BTV-8). Since the available vaccines had not yet been registered and only limited data were available on their performance, a safety study was conducted with three different inactivated monovalent vaccines under consideration for use in Germany. A total of 1007 sheep and 893 cattle were vaccinated and subsequently compared with 638 control animals (324 sheep and 314 cattle). During the study, all animals remained in good health condition. After the initial immunisation, only local swellings were observed in a small number of animals. Following revaccination, several sheep developed more distinct local reactions and a temporary rise in body temperature. Severe systemic reactions were not detected in any of the study groups. Among cattle, neither fever, nor a decrease in milk production and only temporary low-grade local reactions were observed. Overall, our results demonstrate a high level of safety of all vaccines tested. [Copyright &y& Elsevier]

This contribution contains an overview on process analysis and process development in the field of fixed-bed processes for gas–gas and gas–solid reactions. The examples are mainly taken from the work performed during the last 20 years at the Institut für Chemische Verfahrenstechnik in Stuttgart. Its main intention is to show how process analysis and process intensification can benefit from the simplified representation of typical thermal reaction front patterns which evolve in such reactors. Favourable patterns should be used as natural building blocks for the robust design of integrated processes. The processes considered include heat integrated processes for exothermic and endothermic gas–gas reactions as well as exothermic gas–solid reactions, with a special view on automotive Diesel exhaust purification. [Copyright &y& Elsevier]

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Eighteen pre-extracted samples derived from a subaquatic riverine sediment core taken from the Teltow Canal, Berlin (Germany), were treated by off-line TMAH-thermochemolysis and subsequently analyzed by GC-MS to investigate release and thermodegradation of non- extractable anthropogenic organic compounds (bound residues). Furthermore, six selected samples from the lower core section were additionally treated by off-line pyrolysis. Due to former investigations of the extractable fraction of Teltow Canal sediments, high amounts of compounds structurally related to the pesticide DDT (1,1,1-trichloro-2,2- bis(4-chlorophenyl)ethane) were anticipated within the nonextractable fraction. It has been shown that DDT-related bound residues can be gathered by pyrolysis and TMAH-thermochemolysis. Among other compounds, the experiments revealed two DDT-related degradation products (DDPU (3,3-bis(4-chlorphenyl)-1-propene) and DDPS (1,1-bis(4-chlorophenyl)propane)) which were detected for the first time in the environment. The latter compounds may represent formerly unknown metabolites or hints for the existence of carbon-carbon incorporated DDT-metabolites. Both methods tend to produce artifacts which complicate the interpretation of the results. With more knowledge on mechanisms occurring during application of pyrolysis and thermochemolysis, both methods can serve as valuable tools for analyzing bound residues in sediments. [ABSTRACT FROM AUTHOR]

Abstract: Some of the several hundred Lusatian mining lakes originating from lignite mining will be among the largest and deepest lakes in Germany. A special problem of many of these lakes is severe acidification. According to the EC Water Framework Directive (WFD), artificial lakes larger than 0.5km2 have to be monitored and managed in order to establish or maintain a state of so-called good ecological water quality. Therefore the WFD demands the definition of type-specific reference conditions as those of the closest comparable surface water body type in nature, such as natural acidic volcanic crater lakes or oligo- to mesotrophic neutral hard water lakes. We propose a classification scheme for mining lakes applying acidity and planktonic colonization as criteria. Five types of lakes are distinguished ranging from extremely acidic to neutral hard water lakes. Phytoplankton and especially metazoan zooplankton are introduced as intriguing and simple indicators for different states of ecological quality in highly acidic mining lakes. We recommend that extremely and very acidic lakes should remain in the acidic state to protect these as valuable ecosystems, whereas moderately and weakly acidic lakes can be managed by external flooding, chemical or ecotechnological measures to achieve neutral water quality conditions necessary for recreation or fishery use. [Copyright &y& Elsevier]

Abstract: To retrieve insights into abuse/dependence of methylphenidate (MPH) in Germany, a query of a pharmacovigilance database was performed (observation interval: 1993 until 2012). From 1190 reports of any ADR related to MPH, n=23 (2%) cases of MPH abuse were identified (mean age 29 years; male sex 78%; mean daily MPH-dosage 111±126.6mg). As oral application was predominant (70%), the majority of reported cases of MPH abuse might be due to pharmacologic neuroenhancement. [Copyright &y& Elsevier]

Reports on the description of a room-temperature reaction that could be performed in water to convert a phosphine and an azide to a corresponding primary amine and phosphine oxide by Hermann Staudinger in 1919 in Germany. Exploration of new methods to tag sugar molecules on cell surfaces; Introduction of functional groups that neither interfere with endogenous cellular functions nor be inappropriately recognized by the host; Significance of azide and phosphine for Staudinger reaction to take place.