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Advanced codicological studies of Cod. germ. 6 (Hamburg, Staats- und Universitätsbibliothek): Part 2
(2018)
The work presented here follows the article Combining Codicology and X-Ray Spectrometry to Unveil the History of Production of Codex germanicus 6 (Staats- und Universitätsbibliothek Hamburg), published in 2014.1 It confirms the main result of the previous article: the Artusnotiz, the fourth text in the bound manuscript, must have been introduced as the last one. This paper offers further details of the codex production, based on the composition of the black and red inks collected in four measurement campaigns. Furthermore, using imaging μ-XRF, we succeeded in understanding the strong variation of the composition of the red inks in the initials of all the texts except for Parzival and Jeanne d’Arc.
During the last decades the material composition of buildings has become increasingly diverse. However, largely sorted material flows are needed for generating high quality secondary building materials. The use of secondary building materials can meet the requirements of sustainability in several ways: the extended time availability of primary raw materials and, thereby, the preservation of natural resources as well as the conservation of landfill sites.
Recycling of gypsum (calcium sulfate) can be a good example for the environmental benefits of closed-loop recycling. The content of sulfates in other secondary building materials, in particular in recycled concrete aggregates, should be minimized for quality reasons. In contrast, separated gypsum can also be used in gypsum production if the high quality requirements for the recycled gypsum are met. Since almost all processing steps in the recycling process are associated with environmental impacts, an environmental evaluation of the use of recycled gypsum as a substitute in gypsum production has to be carefully conducted.
This paper focusses on the techniques for generating recycled gypsum from gypsum plasterboards, the related quality requirements and a comprehensive environmental evaluation of the complete process.
Die Präsentation erläutert die Hintergründe der nationalen Anforderungen für die Verwendung von Kunststoffdichtungbahnen in Deponieabdichtungen. Die Beständigkeit wird diskutiert. Anforderungen an das Qualitatsmanagement während der Produktion der Produkte und der Bauphase werden aufgezeigt und die Auswirkungen auf die langzeitige Funktionserfüllung werden beschrieben.
It is well documented that throughout Antiquity, ancient Egyptians used mostly carbon inks as a writing material. In Late Antiquity, some metals started to be added to carbon based inks. We have records of five manuscripts from the Dead Sea Scrolls collection whose carbon inks were found to contain copper Also, lead was recently found as an additive in carbon inks on a charred fragment from Herculaneum. Furthermore, the earliest evidence of iron-gall ink was found in the Book of Proverbs (Codex Ms. Berol. orient. oct. 987) dating to the third fourth centuries ce. It has been suggested that along with carbon and iron-gall inks, there is no reason to think that purely tannin inks were not also in use in Egypt. However, so far, we just have evidence of a copper-tannin ink identified in a number of documents from Egypt in the first third centuries bce. In an attempt to fill this gap in this extremely fragmented scenario during our studies of the socio-geographic history of inks, we arrived at the conclusion that the continuous production of Coptic manuscripts from Late Antiquity to the Middle Ages offers a unique opportunity for the historical study of inks across a large geographic area.
The mayor part of the Berlin collection `Manuscripta Americana´ consists of documents compiled by Alexander von Humboldt. The diversity of the written fragments and their shape presume few accordance concerning purpose, place or time of production. Even before the papers came to Berlin, manuscripts were copied, divided and collected by famous scholars also in Mexico. Back in Europe, Humboldt visited further collections and published the detected hieroglyphic writings altogether with cultural objects and landscapes in the book `Vues des Cordillères et Monuments des Peuples Indigènes de l`Amerique, voyage de Humboldt et Bonpland´, labelled corresponding to the cultural background.
By scientific and culture historical analyses, the Humboldt codices are revised and related to each other and others. In especial, the compilation of fragments shown on plate 36 in the book is looked at more closely. Whereas most of the plates represent only one sheet of painted amate paper, here segments with details of seven fragments are put together. It is tried to comprehend why these pieces are on one plate.
To find out a common feature of the documents, their content and represented form are compared. A correlation between some pieces is obvious and thus is also expected in the manufacture of the codices, in the kind of material used. For this the inks and colors are determined by scientific analysis including XRF-, Raman-, FTIR- and VIS- spectroscopy. Special material is detected and related to results of former analysis of codices written during the colonial period of America. Herewith a clear cultural assignment of the manuscripts is performed.
A relation of the fragments represented on plate 36 among each other and to other codices of the collection Manuscripta Americana in Berlin is discussed. Also, if the manuscripts are unique `originals´ or represent fragments of documents, whose corresponding pieces maybe found- in the best case- incorporated in other collections. We detected, that at least two of them can be put into relation to similar manuscripts deposited in Mexico. Further material analysis should clarify, if the corresponding pieces are identical- from one document, or if one of them is a copy. Herewith an approximation to authenticity features and history is issued.
Soil microbes are exposed to different environmental stressors originating from various sources. Biocides used as material preservatives can represent environmental stressors since they are in direct contact with the environment including soil. Microorganism in soils can adapt to stress by different mechanisms; for example, by the evolution of resistance by de novo mutations or acquisition of resistance genes via horizontal gene transfer (HGT). Here, we hypothesize that material preservatives could enhance the evolution of biocide resistance enabling the potential for cross-resistance to antibiotics. Furthermore, we hypothesize that material preservatives can cause increased frequencies of HGT (i.e. altered community permissiveness) facilitating microbial community adaptation to stress. We will culture soil microorganism with increasing concentrations of selected biocides followed by antibiotic susceptibility determination. Moreover, we will incubate soil mesocosms with selected biocides to investigate if these compounds promote HGT of plasmids that carry resistance genes in soil microbial communities. Together these results will elucidate the potential for the evolution of biocide resistance and cross-resistance to antibiotics as well as the effect of biocides on adaptation to environmental stressors in soil microbial communities.
Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants.
However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future.
Construction with geosynthetics has various advantages, but it has to be ensured that there is no negative environmental impact from the application of geosynthetics in hydraulic engineering.
It is expected that any effect will be visible only on the long-term. Therefore, accelerated testing is needed to derive requirements for geosynthetics in hydraulic engineering.
The challenge of the project ASHES is focused on the recycling of nutrients from residues of thermochemical processing of by-products of sugar cane industry (bagasse/straw) in Brazil to increase the energy efficiency of thermal conversion and to enable the recycling of process ashes as fertilisers. Dry lignocellulosic biomass (straw, bagasse) are combusted, gasified and subsequently combined with post-thermochemical treatment in the AshDec process to increase the plant availability of phosphorus. Different fertilizer formulations are granulated/pelletized and tested regarding their storage/handling characteristics.
Biofilm formation on materials leads to high costs in industrial processes, as well as in medical applications. This fact has stimulated interest in the development of new materials with improved surfaces to reduce bacterial adhesion.
We present a flow chamber system to test and quantify bacterial adhesion on materials that are part of antifouling concepts. The adhesion process is standardized and can be adapted to different bacteria in subaquatic of subaerial environments. It is combined with a standardized evaluation procedure based on statistical evidence.
Recent studies have shown that host-microbiota interactions can lead to dramatic changes in host phenotype especially behaviour. We investigate the causal drivers of microbe-associated shifts in host phenotype by examining how feeding behaviour is modulated by a bacterial infection in an omnivorous cockroach: Blatta orientalis. We conducted food-choice experiments after challenging hosts with the common entomopathogenic soil bacterium Pseudomonas entomophila to understand the impact of bacterial pathogens on host macronutrient preference. We find that immune challenge by this bacterium drives a sharp decline in carbohydrate intake and results in a relative increase in the ratio of protein to carbohydrate consumed. Additionally, infected cockroaches reduce their overall nutrient intake. We show for the first time that cockroach feeding behaviour is dynamically modulated by a pathogen. In contrast to studies on Spodoptera moths, this modulation does not impact any of the immune parameters we measured: it does not affect the abundance of immune related proteins in the hemolymph, hemolymph antimicrobial activity, or survival. This leads to the possibility that as long-lived omnivorous species B. orientalis may be better adapted to unpredictable variation in food availability and quality. An illness-induced anorexia-like response which is thought to assist hosts in limiting nutritional resources available to pathogens is therefore the most likely cause of the observed phenotype. Reduction of carbohydrate intake by sick individuals would be consistent with such an explanation.
In another cockroach species Blatella germanica we also investigate whether in addition to pathogens, host microbiota especially gut commensals are causally responsible for shifts in host behavioural phenotype and immune competence. To address this, we conduct food-choice and immunechallenge experiments in germ-free cockroaches and naïve cockroaches.
Zearalenone (ZEN) and its sulfate and glucoside conjugates have been detected in (a broad variety of) food and feed commodities1. Both conjugated derivatives are formed as part of fungal or plant secondary metabolism and thus, belong to the group of modified mycotoxins2. After consumption of contaminated foodstuff, the conjugates can be hydrolyzed by human intestinal microbiota leading to liberation of ZEN that implies an underestimation of the true ZEN exposure. In order to include ZEN conjugates in routine analysis, as well as for toxicological investigation reliable standards are needed.
The objective of the present study was to develop a simple and economic method for biosynthesis of ZEN conjugates. Preceding experiments on the biotransformation of ZEN by Rhizopus and Aspergillus species showed a mixed metabolite formation3. Therefore, these known ZEN conjugating fungal strains were screened for their potential to selectively synthesize the ZEN derivatives ZEN-14-sulfate (Z14S), ZEN-14-glucoside (Z14G) and ZEN-16-glucoside (Z16G). The screening was conducted by adding ZEN to liquid fungal cultures. Cultivation conditions and ZEN incubation time were varied. All media samples were analyzed for metabolite formation by HPLC-MS/MS. Z14S was exclusively formed by A. oryzae. Under optimized conditions a specific biosynthesis of Z14G by R. oryzae and Z16G by R. oligosporus was achieved. After liquid-liquid-extraction and preparative chromatographic cleanup 1H-NMR purities of ≥ 73% for Z14S, ≥ 82% for Z14G and ≥ 50% for Z16G were obtained. In addition, a consecutive biosynthesis was developed by first using Fusarium graminearum for ZEN biosynthesis on rice based liquid medium. After inactivation of Fusarium the subsequent conjugation reaction was conducted utilizing Aspergillus and Rhizopus species under the various optimized conditions.
In this study an easy and cost-efficient biosynthesis for Z14S, Z14G and Z16G was developed. The developed biosynthesis could be also used for other metabolites like ZEL conjugates. Our results of the in vitro screening indicate also the formation of a ZEL-glucoside and α ZEL-sulfate as major metabolites by R. oryzae. In sum, under optimized cultivation conditions fungi can be easily utilized for a targeted and stereospecific synthesis of ZEN conjugates.
The Cairo Geniza is an “archive” discovered in the 19th century in Ben Ezra Synagogue in Fustat, a district in Old Cairo (Egypt). The collection of mostly Jewish documents that vary in genres, languages and writing supports contains a large number of early medieval Hebrew manuscripts.
The Geniza provides sources for the literary, linguistic, historical studies of the various aspects Jewish life. As the documents attest, at least two Jewish communities co-existed in Fustat up to 11th century: a so-called Babylonian and Palestinian. These communities had different leaders, different traditions and lived independently. The differences seem to manifest themselves also in the paleographical, codicological and some material properties of the manuscripts produced by each community.
The aim of this project is to compare the inks used in the Jewish documents depending on different variables: support (paper, parchment), purpose of the manuscript (legal, private, religious), provenance of the scribe. For the determination of the inks type and composition we had to choose non-invasive, non-destructive and portable techniques to analyze the corpus directly on-situ.
The analyses were carried out with a micro-X-ray spectrometer ArtTAX® (Bruker GmbH) and a digital stereomicroscope features built-in LED illumination at 395 nm and 940nm, Dino Lite.
We would like to stress that though the methods of material analysis listed above have been successfully employed in the field of cultural heritage and conservation including ancient and medieval manuscripts they have not yet been used to study fragments from the Cairo Genizah. Therefore, we believe that this research project is a pioneering study that will provide new insights into the history of Hebrew writing materials, their production techniques and materials and, thus, contribute new data to the field of Hebrew paleography.
The Cairo Genizah is a well-known “archive” discovered in the 19th century in Ben Ezra Synagogue in Fustat, a district in Old Cairo (Egypt), located south of the center of modern Cairo. The giant collection of mostly Jewish documents that vary in genres, languages and writing supports contains a large number of early medieval Hebrew manuscripts, mostly in fragmentary form. The larger part of the Cairo Genizah is stored today in the Cambridge University Library, containing about 200,000 fragments.
The Genizah provides sources for the literary, linguistic, historical studies of the various aspects Jewish and non-Jewish life. As the documents attest, at least two Jewish communities co-existed in Fustat up to 11th century: a so-called Babylonian and Palestinian. These communities had different leaders, different traditions and lived independently. The differences manifest themselves also in the paleographical properties of the manuscripts produced by each community.
Although Genizah manuscripts have attracted a great deal of scholarly attention, the material aspects of these documents seem to have been largely neglected. The current study aims to obtain information on the composition of the writing supports and the inks used, in order to obtain insights on trade, local production techniques and social structures.
Can we extend the differences detected by the paleographical analysis to differences in composition of the writing materials ? Can we relate the differences in the composition to a community, to the manuscript type (legal, private...), or to another criterion?
X-ray fluorescence analysis, due to its non-destructive nature and ist suitability to work with historic objects in situ, quickly became one of the most important methods for the evaluation of iron-gall ink. The main advantage of this qualitative and semi-quantitative method is that it makes it easy to differentiate between inks, based on the assumption that the differences result from the manufacture of the ink.
This work explores the question whether the ink ‘fingerprint’ results strictly from the elemental composition of the basic ink ingredients even if it is stored in vessels made of metals or metal alloys. In addition, we tested and compared the performance of three different XRF spectrometers.
We prepared various lab-grade inks according to historical ink recipes and measured the metal content of the ink deposited on sized cotton Linters paper with three types of XRF spectrometers: a simple hand-held device with an interaction spot of 4 mm and two devices equipped with poly-capillary Xray optics for line scanning and imaging. Since the exact elemental mass composition of the non-aged ink samples was known, we were able to evaluate the accuracy of the research procedure. Lab-grade inks were then aged in the metal jars imitating inkwells. The aging of the inks in the metal containers resulted in the significant change of the primary inks fingerprint as opposed to that of the control inks stored in glass containers. This effect was independently confirmed by the measurements conducted with every instrument we used. We will present a brief comparison of the results 43 achieved when using different spectrometers and a possible hypothesis explaining the processes that occurred.
Without precaution, insects may cause serious damage to Museum collections. Quarantine of potentially infested objects can be logistically challenging. Anoxia under controlled nitrogen atmosphere is a most compatible but also time-consuming method to eradicate insect pests in all kinds of different materials. Treatment results are usually effected by duration, temperature, humidity and residual oxygen content. During a two-year research project, 34 relevant pest insect species of all developmental stages were tested in several different materials (wood, paper, wool) to monitor treatment success and to determine optimum treatment parameters. Duration of Treatment ranged from one to three weeks at temperatures of 20 - 27 °C.
As expected, results showed significant differences in mortality among tested species. Highest tolerance of hypoxic conditions was found in older larvae of Hylotrupes bajulus. However, this species is an unlikely museum pest. Anobiids and other wood boring beetles are more often an issue related to cultural heritage. Tested imbedding materials in general had no mortality lowering influence. A combination of three weeks exposure time at up to 0.5 % residual oxygen and at 24 °C and 50 % RH is recommended for infested artefacts.
A wide range of methods are used to estimate the plant-availability of soil phosphorus (P). Published research has shown that the diffusive gradients in thin films (DGT) technique has a superior correlation to plant-available P in soils compared to standard chemical extraction tests. In order to identify the plant-available soil P species, we combined DGT with infrared and P K- and L-edge X-ray adsorption near-edge structure (XANES) spectroscopy. This was achieved by spectroscopically investigating the dried binding layer of DGT devices after soil deployment. All three spectroscopic methods were able to distinguish between different kinds of phosphates (poly-, trimeta-, pyro- and orthophosphate) on the DGT binding layer. However, infrared spectroscopy was most sensitive to distinguish between different types of adsorbed inorganic and organic phosphates. Additionally, also intermediates of the time-resolved hydrolysis of trimetaphosphate in soil could be analyzed. Furthermore, infrared and XANES microspectroscopy make it also possible to analyze P compounds on the binding layer with a lateral resolution down to 1 µm2. Therefore, P species of a spatial soil segment (e.g. rhizosphere) can be mapped and analyzed.
Comparison of Formaldehyde Concentrations in Emission Test Chambers Using EN 717-1 and EN 16516
(2018)
For many years EN 717-1 (Wood-based panels - Determination of formaldehyde release - Part 1: Formaldehyde emission by the chamber method) is the standard for formaldehyde emission testing of wooden boards. In 2017 EN 16516 (Construction products - Assessment of release of dangerous substances - Determination of emissions into indoor air) was published as a new harmonised standard for the emission testing of construction products. Because test chamber conditions are different, both standards give different concentrations for formaldehyde. For the determination of a conversion factor four test series were set up with different wooden boards.
Comparison of Formaldehyde Concentrations in Emission Test Chambers Using EN 717-1 and EN 16516
(2018)
For more than 25 years EN 717-1 (Wood-based panels - Determination of formaldehyde re-lease - Part 1: Formaldehyde emission by the chamber method) is the standard for formalde-hyde emission testing of wooden boards. In 2017 EN 16516 (Construction products - Assess-ment of release of dangerous substances - Determination of emissions into indoor air) was published as a new harmonised standard for the emission testing of construction products. Because test chamber conditions are different, both standards give different concentrations for formaldehyde. To determine a conversion factor four test series were set up with different wooden boards. For a loading of 1 m²/m³ the conversion factor is 1.6. This means that the formaldehyde concentration measured under the conditions of EN 16516 is a factor of 1.6 higher compared to EN 717-1.
The Cairo Geniza is an “archive” discovered in the 19th century in Ben Ezra Synagogue in Fustat, a district in Old Cairo (Egypt), located south of the center of modern Cairo. The giant collection of mostly Jewish documents that vary in genres, languages and writing supports contains a large number of early medieval Hebrew manuscripts, mostly in fragmentary form. The larger part of the Cairo Geniza is stored today in the Cambridge University Library (CUL).
The Geniza provides sources for the literary, linguistic, historical studies of the various aspects Jewish life. As the documents attest, at least two Jewish communities co-existed in Fustat up to 11th century: a so-called Babylonian and Palestinian. These communities had different leaders, different traditions and lived independently. The differences seem to manifest themselves also in the paleographical, codicological and some material properties of the manuscripts produced by each community.
The aim of this project is to compare the inks used in the Jewish documents depending on different variables: support (paper, parchment), purpose of the manuscript (legal, private, religious), provenance of the scribe. For the determination of the inks type and composition we had to choose non-invasive, non-destructive and portable techniques to analyse the corpus directly in the CUL.
The analyses were carried out with a mobile energy dispersive micro-X-ray spectrometer ArtTAX® (Bruker GmbH, Berlin, Germany), which consists of an air-cooled, low-power molybdenum tube, polycapillary X-ray optics (measuring spot size 70 µm in diameter), an electrothermally cooled Xflash detector, and a CCD camera for sample positioning (Bronk et al 2001, Hahn et al. 2010). All measurements are executed using a 30 W low-power Mo tube, 50 kV, 600 µA Mo tube, and with an acquisition time of 15 s (live time) to minimize the risk of damage (Fig. 1, 2).
Fig. 1: XRF spectrometer probe above a manuscript fragment
Fig. 2: Typical element profile of a XRF linescan
The Dino Lite digital stereomicroscope (Fig. 3) features built-in LED illumination at 395 nm and 940 nm and a customized external white light source. During use, the microscope is fastened to a small tripod or mounted on a Plexiglas ring holder that incorporates a white light source.
Fig. 3: Dino Lite digital stereomicroscope
Fig. 4: Details of one fragment (T-S 16.124) observed with the Dino microscope (x20). On the left, when illuminated with NIR (Near-Infrared, 940 nm) light, the ink fades, indicating iron-gall ink. On the right, the image under NIR light does not change. It is carbon ink.
On example of these studies is the manuscript T-S 16.124 (Cambridge University Library, Fig. 5) whom belongs to the third corpus. It is a deed, written in Hebrew, dated from 1328 (= 1017 CE) and witnessed by a very high number of people (6) comparing to the standard of similar documents (between 2 and 3), from at least two different Jewish communities in Fustat (trans congregational). The verso is written in Arabic (Bareket 1999).
Fig. 5: Manuscript T-S 16.124 (Cambridge University Library)
To compare the inks, we used the fingerprint model. This method relies on the determination of characteristic elemental compositions and represents the amount of a minor constituent relative to the main component, iron in iron gall ink (Malzer et al. 2004, Hahn et al. 2004, Rabin et al 2014). However, a calculation of a fingerprint based on XRF measurements is not possible in the case of carbon ink since carbon, its main component, cannot be detected with this technique.
Fig. 6: Ink fingerprint T-S 16-124 (recto) normalized to iron (Fe)
Conclusion
We show that using reflectography and XRF analysis it is possible to sort the inks according to their type. In the case of the iron-gall inks, use of the ink fingerprint, i.e. amount of the vitriol components normalized to iron we can make direct comparisons of the ink composition.
We would like also to stress that though the methods of material analysis listed above have been successfully employed in the field of cultural heritage and conservation including ancient and medieval manuscripts they have not yet been used to study fragments from the Cairo Genizah. Therefore, we believe that this research project is a pioneering study that will provide new insights into the history of Hebrew writing materials, their production techniques and materials and, thus, contribute new data to the field of Hebrew paleography.
While studying the socio-geographic history of inks, division 4.5 of the BAM (Bundesanstalt für Materialforschung und Prüfung) together with the Centre for the Study of Manuscript Cultures in Hamburg has developed a protocol for ink analysis. It consists of a primary screening to determine the type of the ink, and a subsequent in-depth analysis using several spectroscopic techniques. The XRF elemental analysis aims primarily at understanding the fingerprints of inks containing metals, making it possible to distinguish among different inks.
Our own research aims primarily at recreating a socio-geographic history of inks, parchment, and papyrus and includes the comparative analysis of the writing materials of the Dead Sea Scrolls, ink and papyrus in Ancient and Hellenistic Egypt, and inks in documents from various contemporary medieval communities in Fustat (first nucleus of Cairo). During many years of study, we concluded that the continuous production of Coptic manuscripts from late Antiquity to the Middle Ages offers a unique opportunity for historical study of the ink in a large geographic area. Thanks to the collaboration with the ERC project “PAThs” (www.paths.uniroma1.it), based at the University of Rome La Sapienza, and within the activities of a PhD research dedicated to this topic, we therefore created a new branch of our project focused entirely on the analysis of Coptic inks, pigments, and dyes. This pioneering systematic study of writing materials coming from a specific area and time frame (5th-10th century) aims not only at a better understanding of the complex Coptic multicultural and plurilingual society, but also and mainly at clarifying the links among the Coptic and other societies between the ancient and medieval eras. Finally, it will cast light on the history of the technological development of inks in the eastern world, from Antiquity to the middle ages.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
The presentation gives an overview about the use of ecotoxicity testing in assessment of waste. Especially in cases with unknown composition this kind of test are useful. Recently, the assessment of the hazard property HP 14 "ecotoxicity" for the labelling of waste was published. The labelling procedure is explained in detail.
Synchrotron XPS in the soft-X-ray regime is suitable for the detection of light elements commonly found in biological samples. Various model systems of biofilms have been developed and characterised at synchrotron- and lab-based facilities. By obtaining the chemical composition at various information depths, the vertical distribution of iodine in an artificial biofilm have been determined.
Development of a methodical approach for in-situ analysis of modern reverse paintings on glass
(2018)
The technique of painting on the reverse side of glass was rediscovered by artists in the early 20th century and gained great popularity, especially in Germany. In contrast to other paint techniques (e.g. panel and mural painting), the paint layers are applied in reverse succession starting with the foremost paint layer and ending with the primer (backmost layer). The paintings are viewed in reflected light, thus revealing an impressive gloss, luminosity and depth of colour.
Scientific investigation of the material provides important information for appropriate conservation concepts. Transport of the precious and fragile objects to the lab is often not feasible. Therefore, in-situ, non-invasive analysis is necessary to analyse colorants and binders. However, some analytical problems need to be considered: due to the reverse paint stratigraphy in reverse paintings on glass, the measured layer is always the backmost one. The analytical possibilities are extremely reduced, when the back is covered by a metal foil (or by paper, carton etc.). However, measurements through the glass (using Raman and VIS) can still yield information on the colourants of the front layer.
When the paint layer is accessible, we start our procedure using X-ray fluorescence (Tracer III-SD, Bruker AXS Microanalysis GmbH, 40 kV, 15 μA) and VIS reflectance spectroscopy (SPM 100, Gretag-Imaging AG). Both techniques provide first information on the inorganic colourants. Raman measurements (i-Raman®Plus, Bwtek inc., 785 nm, 50× objective, resolution 4 cm-1) are then carried out to clarify uncertain XRF measurements and to identify synthetic organic pigments (SOP). Diffuse Reflection-Infrared-Fourier-Transform Spectroscopy (DRIFTS; ExoScan, Agilent GmbH, 4000–650 cm-1, 500 scans, spectral resolution 4 cm-1) is used for the classification of the binders. Moreover, it may help to identify SOP, when fluorescence dominates the Raman signal. This analytical sequence yields the best results, when time is the limiting factor.
We present two in-situ studies of the paintings “Kreuzabnahme” (1914-15) by Carlo Mense and “Stadt am Morgen” (1921) by Walter Dexel. The painting “Kreuzabnahme” is an outstanding piece in Mense’s ɶuvre, because the glass plate was painted on both sides (Fig. 1). The results of the back-side show mainly inorganic pigments: basic lead white, talc, red and brown ochre, cinnabar, chrome yellow, viridian, ultramarine blue, Prussian blue and bone black. The classification of binding media using DRIFTS yields positive results for drying oil. Acrylic resin could be identified in two areas, resulting from a previous restauration treatment. For the front side painting, Mense used basic lead white, cinnabar, chrome yellow and umbra as pigments and oil as binder.
Measurements of the abstract painting “Stadt am Morgen” by Walter Dexel show zinc white, basic lead white, chalk, cinnabar, red lead, strontium yellow, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, brown ochre and bone black as pigments. Moreover, synthetic alizarin (PR83) was identified as dark red colorant. The results of DRIFTS classify oil as binding media.
We conclude that, the use of complementary spectroscopic methods yields the best results for in-situ analysis of reverse paintings on glass.
Today glass is broadly used in modern architecture. For applications indoor it is possible to produce decor glass by using enamel colors and glass painting techniques without any problems. However, this is more limited for applications outdoor. Humidity and environmental pollution attack the surface of the coating and damage it strongly. There are only few colors on the market which are resistant towards acids and bases until now. Additionally, most of those colors are opaque. In order to extend the color palette, chemically resistant colored glasses are being developed which are transparent, relatively low melting and intensively toned even in thin coat thickness. To achieve such ambitious aim, many parameters have to match which act in complex manner. Metal oxides were used to color the glasses. A lead-free glass composition was developed to avoid an exposition of heavy metals to the environment. The glasses were characterized, in particular in terms of their thermal properties, their crystallization and corrosion behavior as well as their chemical and environmental durability. Different practical applications will be shown.
Fluorometric sensing is a versatile approach for trace analysis outside of the laboratory, requiring suitable sensor materials and their integration into sensing devices. The versatility of fluorophores as probes, especially in terms of the possibility to tailor their optical as well as their recognition properties by synthetic modifications in a wide range, renders them as superior active component for the preparation of optical sensing devices. Recent works at BAM in this field include, for example, the detection of nerve gas agents, illustrating impressively the aforementioned benefits of fluorophores in optical sensing applications.
In the interdisciplinary project presented here, we target hazardous gases such as ammonia, benzene, and hydrogen sulfide, next to others, which pose a major threat to human health and environmental safety and for which the availability of a sensitive and reliable detection method is highly desirable. The dyes presented follow a “turn-on” fluorescence schematic, which allows for the selective and sensitive detection of the respective gaseous analyte. The immobilization of the probe in polymeric matrices is then the next step toward the fabrication of a prototype device for molecular sensing. Further steps in the project include the assembly of instruments for test-atmosphere generation, the referencing of the sensor system, development and implementation of an optical setup, and the testing of the prototype device under laboratory conditions and in the field.
In this presentation, we give an overview over the recent developments on this topic in our groups. Highlights are hydrogen sulfide sensitive, BODIPY based transition metal complexes, which allow for a sensitive as well as selective detection of the toxic gas. In addition, we present a novel class of highly substituted BODIPY derivatives – pocket-BODIPYs – which are of a synthetically high versatility and can readily be modified to create pockets in the periphery of the molecule of defined geometries. This is illustrated on the successful encapsulation of benzene by a pocket-BODIPY derivative, confirmed by X-ray crystallographic analysis as well as by further spectroscopic and analytical methods.
The technique of painting on the reverse side of a glass panel was rediscovered by German artists at the beginning of the 20th century. They appreciated the impressive gloss, luminosity, and depth of colours in this genre. Compared to stained glass, the distinctive properties of this technique are: (1) the paint is applied “cold”, hence, it doesn’t involve a firing step, (2) reverse paintings on glass are framed and always viewed in reflected light and (3) the reverse paint stratigraphy is different from canvas paintings, starting with the front most layer and ending with the backing layer. In 1908 several artists, including Gabriele Münter, Wassily Kandinsky, Heinrich Campendonk, August Macke and Franz Marc of the “Der Blaue Reiter” (the Blue Rider) collective took an interest in this technique and started to share their interest with other colleagues in Europe. Our pioneering project is tracing this transfer of knowledge by a multidisciplinary approach in terms of art history, paint technology and material science. More than 100 artists and >1000 reverse paintings on glass were identified during the project. This high number of objects clearly points out that this technique was by far more important for modern art than previously assumed. In-situ, non-invasive measurements (XRF, Raman, VIS, DRIFTS) on a well-considered selection of 67 paintings reveal the broad palette of colorants ranging from traditional to experimental. Special attention is paid to the impact of synthetic organic pigments (SOP) in artists palette. Demonstrative examples by W. Kandinsky, L. G. Buchheim and F. Jespers are used to discuss analytical challenges and highlights.
Direct and indirect effects (DIERec) of the recovery of secondary resources are in the range of 500 million tonnes per year in Germany; energy savings are 1.4 million TJ. These savings are between 10 and 20% of the total. The effects of materials recovery exceed those of energy recovery by far with the exception of secondary plastic material where DIERec from energy recovery is higher by factor of 2.7. Untapped potential for the recovery of secondary resources exist in the fine fraction of bottom ash from municipal solid waste incineration, mainly Cu and precious metals and in urban mining.
The characteristics of different molecules chosen as representatives for specific functionalities in conditioning layers play an important role on attachment behavior and later biofilm formation of bacteria. The chemical composition is a major component influencing the attachment but there is a conglomerate of influences.
Technical advances in the study of molecular evolution have crystallized the fundamental insight that many bee pathogens evolve and adapt over timescales that overlap with host ecology. At the same time, the role played by bee host community ecology is increasingly being appreciated in host-parasite interactions. Here, we focus on Deformed wing virus (DWV) and present recent studies exploring the link between virulence, DWV genetic diversity and changes to host ecology - namely the arrival of an invasive ectoparasite, the Varroa destructor mite, which vectors viruses between honeybees. Specifically, we show how V. destructor may have created conditions for the emergence of more virulent strains of DWV in the western honeybee, Apis mellifera. We present a molecule-to-ecology framework to help interpret findings and to guide future hypotheses, emphasizing the role of molecular interactions between viruses and host immunity as drivers of change at the bee population level.
Environmental sustainability and –stability of Materials concerning the Migration of pollutants
(2018)
MaUS is an acronym for ”Material und Umweltsimulationen“. Plastics are in the focus of environmental politics due to their long-term behaviour and therefore to their persistence. Not only that they appear as visible contaminants in the sea and on the beach, but their unknown behaviour concerning their additives as well as the related transformation products are anxious. Therefore, we wish to establish a certified reference method to provide a method for testing plastics.
Aim of this project is the development of fast motion standard reference methods for testing plastics regarding to their environmental compatibility. To establish these testing methods, we use polystyrene (PS) and polypropylene (PP) with environmental relevant brominated flame retardants, known for their persistent bioaccumulative and toxic (PBT) properties. In case of PS the material contains 1 wt% of 1,2,5,6,9,10-hexabromocyclododecan (HBCD) and in case of PP 0.1 wt% bromodiphenylether (BDE-209), which is known as a substance of very high concern (SVHC). Furthermore, we use polycarbonate (PC), which is still used as material in baby flasks and releases Bisphenol A (BPA), an estrogenic active substance.
As an additional material PTFE is used for its importance as a source for two ubiquitous environmental substances (PFOS and PFOA), whose toxicological effects are still incompletely known.
The focus in this current work is set on the transfer of potential pollutants out of applied materials mentioned above into environmental compartments like water or soil. Here an accelerated aging concept should be developed to shortened time consuming natural processes. For these resulting simulations we use a programmable weathering chamber with dry and wet periods and with high and low temperatures. These programmes run for several weeks and according to a defined sampling schedule we take water samples, run a clean-up procedure by SPE (Molecular imprinted polymers (MiPs) resp. polymer-based cartridges (Waters Oasis HLB)) and analyse them by HPLC-UV resp. LC-MS/MS. Of most interest in case of flame retardants are photocatalytic transformation products. Therefore, we conduct a non-target-screening resp. a suspected target-screening by LC-MS/MS and HRMS.
The halophilic bacterium Halomonas elongata can tolerate salt concentrations above 10% NaCl and uses the accumulation of the compatible solute ectoine as a major osmoregulatory mechanism. Ectoine can be accumalted inside the cell through import from the medium or de novo synthesis and establishes an osmotic equilibrium with the surrounding1. Ectoine also protects proteins from the effects of freezing, drying and high temperatures4 and DNA from ionizing radiation2. These features make ectoine a valuable compound for cosmetics and medical devices.
H. elongata was originally isolated from a solar salt facility, where it thrives under high salt concentrations. It was found that marine prokaryotes, which are exposed to high oxidative stress in their environment, vary glycolytic strategies5. A variation in the use of the glucose metabolic pathways is also assumed for H. elongata.
Bee populations have declined significantly in recent years and this is thought to be attributable at least in part to the (re-)emergence of viruses. These viruses are predominantly positive single stranded (+ss) RNA viruses belonging to the Picornavirales. Managed honeybees are often infested with the invasive mite, Varroa destructor, which vectors RNA viruses including Deformed wing virus (DWV, family Iflaviridae): a leading culprit of colony losses. Many bee viruses have been sequenced and structural features are now available for viruses such as DWV. DWV consists of at least 3 distinct genotypes, two of which have been shown to be differentially virulent in honeybees. Molecular studies have demonstrated that DWV has a mean evolutionary rate of 1.35 x 10-3 per site per year. For such viruses – in contrast to their eukaryotic hosts – ecological and evolutionary timescales significantly overlap. This rapid evolution allows RNA viruses to adapt quickly to novel host environments with recombination representing an additional key source of genetic variation. Interestingly, recombination between genotypes of DWV has recently been shown to be a common occurrence in honeybees. A challenge has been to develop bioinformatics tools that can accurately reconstruct viral haplotypes – including recombinants – from heterogenous high-throughput sequence data.
The impact of blood-to-blood Varroa destructor transmission on virus evolution represents an important question in bee virus research. Due to the nature of the V. destructor life cycle, predictions can be made about the potential impact of the mite on virus virulence evolution. Specifically, the developing honeybee host pupa should remain alive until close to the completion of metamorphosis to provide sufficient time for successful mite reproduction, including offspring mating. For optimal transmission, any virus found in a mature and mated daughter mite will hold a significant selective advantage over a virus found in an immature or unmated daughter mite – placing a cost on virus virulence that impacts honeybee pupae before mites can mate. On the other side, viruses replicating too slowly and with delayed virulence effects will hold a selective handicap because fewer transmission units will be found in mated mites. I have hypothesized that the evolution of virus virulence shifted following the arrival of V. destructor, with viruses, including recombinants and/or specific viral genotypes being selected for a level of virulence in pupae (and likely also in adults) that maximises R0, which represents the basic reproductive number of the virus in the host population. R0 is defined by the number of subsequent infections caused by a single infection and it must be greater than 1 for an infection to spread in a population. It is enhanced by maximising the number of transmission units passed to uninfected susceptible vectors, and ultimately hosts (Figure 1).
Honeybee viruses are also shared with sympatric wild bees and viral prevalence and sequence data indicate frequent virus transmission between managed and wild bee species. In addition to infecting the western honeybee (Apis mellifera), DWV can infect other Asian honeybee species such as Apis ceranae. Outside of honeybees, DWV has been found widely in bumblebees, including solitary bees and wasps and there is evidence that it can actively replicate in several Bombus and solitary bee species. Whether the arrival of the V. destructor mite in A. mellifera has driven viral emergence in non-Apis bees is a target of ongoing research.
Infections with multi-resistant Gram negative pathogens are a major threat to our health system. In order to serve the needs in antibiotics development we selected untapped bioresources and implemented high throughput approaches suitable for the discovery of strains producing antibiotics with anti-Gram negative activity.
Our approaches rely on the hypothesis that Termite associated bacteria are likely to produce potent antibiotics to defend their hosts against entomopathogenic microorganisms. Termite nests and guts harbor suitable, highly diverse microbiomes in which bacterial taxa are present known to potentially produce natural compounds. In
a first step the diversity of Coptotermes species nest microbiomes was assessed carefully by using 16S rDNA amplicon sequencing on the Illumina MiSeq platform and nest material was selected to retrieve viable cells by using Nycodenz density gradient centrifugation. In order to analyze the diversity of the culturable termite nest microbiome, bacterial cells were either distributed in 384-well plates
(approach 1) or encapsulated in small spheric agarose beads by an high throughput microfluidics technique (approach 2). Cultures obtained from approach 1 were scaled-up in 96-well Duetz-systems for characterization of diversity and for rapid supernatant screening using the bioluminescence-labeled E. coli pFU166. The generated
droplets of approach 2 simultaneously received a small population of GFP-tagged Gram negative screening cells and were sorted for low fluorescence using FACS. After elimination of redundancy we performed a fast scale-up of active strains.
Implementation of this pipeline allows us to prioritize antibiotics producing strains in a ultra-high throughput fashion and by cultivation of broad diversity in our approches.
Our understanding of RNA viruses from edible insects is minimal at best, with studies largely focusing on model insect species and those associated with obvious signs of disease. This represents a considerable gap in understanding, given the growing role of insects as a source of food and feed, as well as the more general relevance of insects in agriculture and health. Illness due to entomophagy is rare but well documented, including fatal cases following the consumption of termites. Termites are eaten commonly in tropical Asia, Africa and South America, and are among the insects with the highest recorded fat content. There are many species of termites, with a wide range of diets and habitats centering around the consumption of wood and soil substrates. In this study, we report the results from a survey of more than 30 cockroach and termite transcriptomes, with the aim of understanding the diversity and evolution of RNA viruses as well as other potentially pathogenic organisms that are associated with this relevant but somewhat overlooked group of insects. We discuss our results in the context of the possible zoonotic risk posed by insects, as well as in the context of emerging viral and other disease threats that may face insects being reared at industrial scales.
Near-ambient pressure XPS makes it possible to characterise samples not compatible to ultra-high vacuum, and enables the study of liquid-solid, gas-liquid and gas-solid interfaces. NAP-XPS meas-urements of biofilms, suspended nanoparticles and metal-organic frameworks were performed with EnviroESCA developed by SPECS.
An interesting application is surface characterisation of biofilms, which are bacterial communities embedded in a self-produced polysaccharide matrix. Various model systems ranging from pure polysaccharides of alginate to biofilms harvested directly from the growth medium have been char-acterised in humid conditions[1].
NAP-XPS also makes it possible to characterise nanoparticles in solution. Silver nanoparticles in aqueous solution were characterised and the Ag 3d-spectrum compared to spectra obtained of dried nanoparticles in UHV-conditions[2]. The binding energy of the Ag 3d-core level peak was shifted by 0,6 eV towards higher binding energy for suspended nanoparticles compared to the dried sample measured in UHV. This can be assigned to a change in surface potential at the water-nanoparticle interface.
Metal-organic frameworks (MOFs) are suitable materials for gas storage of small molecules due to their nanoporous, crystalline structure. However, instability in humidity remains an issue for many types of MOFs. XPS-measurements of the MOF-structure HKUST-1 were performed in various NAP-conditions to assess the stability of the sample and its interaction with the gas molecules as water, methanol and pyridine.
The technique of painting on the reverse side of glass was rediscovered by artists in the early 20th century. The artist group “Der Blaue Reiter” around Wassily Kandinsky and Franz Marc got in touch with this technique in 1908 and 1909. In the following years it gained great popularity, especially in Germany. Nevertheless, the technique has not received its due appreciation in art history. It was considered as stained glass. However, the paint layers are applied cold, hence this artistic technique doesn’t involve a firing step.
Our multidisciplinary project investigates the art historic backgrounds, the painting techniques and materials of modern reverse paintings on glass. More than 1000 paintings from ~100 artists were discovered in the framework of our project. A selection of 60 paintings could be analyzed using non-invasive, in-situ methods such as Raman and VIS spectroscopy, Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS) and X-ray fluorescence (XRF). In this paper we want to point out the key role of Raman spectroscopy for our research. It offers the unique opportunity to measure paint layers from both sides. (front = through the glass; reverse = directly on the paint layer).
The technique of painting on the reverse side of a glass panel was rediscovered by German artists at the beginning of the 20th century. In contrast to other paint techniques (e.g. panel and mural painting), the paint layers are applied in reverse succession starting with the foremost paint layer and ending with the primer (backmost layer). The paintings are viewed in reflected light, thus revealing an impressive gloss, luminosity and depth of colour. The artist group “Der Blaue Reiter” (the Blue Rider) around W. Kandinsky and F. Marc got in touch with this technique in the summers of 1908 and 1909 and spread their knowledge in different regions. Our pioneering project is tracing this transfer of knowledge by a multidisciplinary approach in terms of art history, painting technology and material science. More than 100 artists and >1000 reverse paintings on glass (1905-1955) were identified during the project. This numbers clearly point out that this technique was by far more important for modern art than previously assumed. In-situ, non-invasive measurements (XRF, Raman, VIS, DRIFTS) on a well-considered selection of 67 paintings reveal the broad palette of colorants ranging from traditional to experimental materials. Special attention is paid on artists who are strongly connected to Berlin. Demonstrative examples by W. Dexel, G. Muche and L. Hildebrandt are used to discuss analytical challenges and highlights.
The first documentation of fuel biodeterioration dates back to the late 19th century. However, extensive studies concerning the microbial fuel contamination started in 1980’s. Polymeric fuel storage tanks containing diesel and biodiesel provide environmental conditions for microbial growth. Several studies demonstrated that bacteria, which were found in contaminated fuel systems, can use fuels as macronutrient; but such bacteria can also cause microbiologically influenced corrosion and fouling.
The aim of this study is to investigate the initial attachment behavior of bacteria, isolated from a diesel contamination, on neat and photooxidized high-density polyethylene (PE-HD). Two common PE-HD’s, less- and biodiesel-stabilized, were radiated to UV light representing a tank exposed to sunlight. The effect of photooxidiation on PE-HD’s surface were characterized chemically by Fourier-transform infrared spectroscopy (FTIR). The attached bacteria Pseudomonas aeruginosa and Bacillus subtilis on the polymer surface were evaluated by fluorescence microscopy and colony-forming unit tests (CFU).
Microbiologically influenced corrosion (MIC) is the deterioration of metals due to the metabolic activities of microorganisms. Microorganisms can take electrons directly from the metal surface (EMIC) thereby causing corrosion. Well known culprits of EMIC are: sulfate-reducing bacteria (SRB), acetogens and methanogens.
Microbiologically influenced corrosion (MIC) is the deterioration of metals due to the metabolic activities of microorganisms. Microorganisms can take electrons directly from the metal surface (EMIC) thereby causing corrosion. Well known culprits of EMIC are: sulfate-reducing bacteria (SRB), acetogens and methanogens.
Our aims
- Develop a novel flow system to study MIC by methanogens to mimic industrial Environments
- Investigate the inhibitory concentrations of biocides targeting SRB on corrosive methanogenic strains
- Investigate the inhibitory effects of corrosion inhibitors on methanogens
- Compare the inhibitory concentrations to SRB
Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea can also cause MIC by directly withdrawing electrons from the iron surface for methanogenesis. However, the mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite, a by-product of methanogenesis, (4Fe + 5HCO3 + 5H+ 4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes.
Aim of study: In this study, natural durability of some domestic and foreign wood species against Hylotrupes bajulus and Anobium punctatum larvae were tested on laboratory scale
Area of study: This study was conducted at Department of Forest Products Engineering in Duzce University, Turkey and Federal Institute for Materials Research and Testing (BAM), Germany.
Material and Methods: Scotch pine (Pinus sylvestris), fir (Abies nordmanniana), spruce (Picea orientalis), cedar (Cedrus libani), poplar (Populus tremula) and beech (Fagus orientalis) woods were used to test H. bajulus larvae (EN 46-1). Alder (Alnus glutinosa), oak (Quercus cerris), poplar (Populus tremula), beech (Fagus orientalis), maple (Acer carpinifolium), ash (Fraxinus angustifolia), teak (Tectona grandis), ayous (Triplochiton scleroxylon), movingui (Distemonanthus benthamianus), dahoma (Piptadeniastrum africanum), iroko (Chlorophora excelsa), bubinga (Guibourtia tessmannii) and sapele (Entandrophragma cylindiricum) woods were used for A. punctatum larvae (EN 49-1). At the end of the experiment, the mortality rates of the larvae were determined and the size and weights of the surviving larvae were measured.
Main results: F. orientalis and C. libani were found to be the most resistant wood species against H. bajulus larvae while A. nordmanniana was the least resistant. All tropical wood species and oak and maple from domestic wood species showed 100% mortality rate therefore found to be the most resistant against A. punctatum larvae. The most vulnerable wood species was found to be alder with a 35% mortality.
Research highlights: while F. orientalis, C. libani, and P. tremula were found the most resistance wood species against H. bajulus, P. sylvestris and A. nordmanniana were determined as most vulnerable. All tropical wood species and two domestic species (Q. cerris and A. carpinifolium) showed the highest mortality rate as 100%. The least durable domestic wood was determined as alder.
X-ray photoelectron spectroscopy (XPS) provides elemental and chemical information from the outermost ~10 nm of the sample surface. This is in the same order of magnitude as the thickness of the outer bacterial membrane of gram-negative bacteria, as well as outer membrane molecules as exopolysaccharides and lipopolysaccharides, commonly attached to the cell surface. With the development of near-ambient pressure (NAP)-XPS, bacteria can be analysed with minimal sample preparation.
EnviroESCA is a laboratory based NAP-XPS instrument, equipped with a monochromated Al Kα radiation source and a differentially pumped energy analyser connected to an exchangeable sample environment. It allows for measurements in various gas-atmospheres, including water vapor, which makes it possible to characterise bacteria and other biological samples close to their natural, hydrated state. Artificial model-biofilms of exopolysaccharides, planktonic Pseudomonas Fluorescens and biofilms of Escherichia Coli have been characterised in hydrated and dried state.
High-resolution XPS-spectra from carbon, oxygen, nitrogen and phosphorous can be assigned to carbohydrates, lipids and proteins in general agreement with literature. Especially the carbon 1s peak is of interest. A series of measurements of an E. coli biofilm from 11 mbar in humid environment to 1 mbar air reveal changes in the C1s peak, which suggests that the bacterial surface undergo substantial Change.
There is a need for an assessment of the emission properties of volatile organic compounds (VOCs) from consumer products. A method comparison was carried out to evaluate adapted and cost-effective procedures for such items. Smaller and automated emission chambers depicted similar kinetics compared to a 203 L standard chamber. Toy samples made of PVC (Polyvinyl chloride) emitted more VOCs compared to other tested polymeric products. The emissions from 2 selected samples were studied to allow an evaluation of the resulting room concentration and external exposure of a child. Obtained concentrations were not of concern.
There is a need for an assessment of the emission properties of volatile organic compounds (VOCs) from consumer products. A method comparison was carried out to evaluate adapted and cost-effective procedures for such items. Smaller and automated emission chambers de-picted similar kinetics compared to a 203 L standard chamber. Toy samples made of PVC (Polyvinyl chloride) emitted more VOCs compared to other tested polymeric products. The emissions from 2 selected samples were studied to allow an evaluation of the resulting room concentration and external exposure of a child. Obtained concentrations were not of concern.
We demonstrate a 2D platform based on high contrast wetting patterns suitable for miniaturized microbiological assays.
In principal, superhydrophilic spots are surrounded by a superhydrophobic surface area. The special structure of the superhydrophilic functional surface ensures that liquids, e.g. bacterial suspensions or biocide solutions, spread immediately and evenly on this surface without passing the wetting boundary. This feature allows a homogenous distribution of bacteria or chemical substances on well defined lateral dimensions. The superhydrophilic spots may also serve as substrate for bacterial biofilms. Due to the high wetting contrast and the fabrication process, it is possible to minimize the test areas as well as their distance to each other.
We demonstrate the fabrication process of the high wetting contrast platform and also present a microbiological assay as an application example. Advantages of this platform are the use of low volumes and its potential of automated analysis.
Leachiing tests - a useful tool for the environmental impact assessment of construction products?
(2018)
Construction products and waste materials used for construction can be in contact with the environment and may release potential harmful compounds. Information on the total content of these substances in the product is not sufficient to assess its envrionmental impact since it does not consider realistic exposure conditions.The impact of these compounds is often assessed by using the total content in the product. This estimation lacks realistic exposure conditions.
Concerning the pathway to soil and groundwater by contact with rain or seepage water leaching tests, which were developed and standardized by the European Committee for Standardization, are available. While for secondary construction products and waste this investigation of the leaching behaviour is standard procedure and is already part of regulation in Germany (draft ordinance on reuse of mineral waste) and within Europe (landfill directive) the release from primary construction products got in the focus more recently. Several monitoring studies found unexpected high concentrations of substances used as herbicides and fungicides in surface water and stormwater originating from urban areas. As some of these compounds are even banned for the use in agricultural applications in Europe alternative sources as roof materials and façade coatings exposed to rain were suggested. Further field and laboratory tests confirmed construction products as sources of these substances in water.
The aim of this presentation is to show exemplary results of existing leaching methods and underline the strength and weaknesses of the test system with selected examples from our work. We especially draw the attention to the research which is still needed to close the gap between the results of leaching experiments and the subsequent risk assessment of the products.