TY - JOUR A1 - Cervino, C. A1 - Knopp, D. A1 - Weller, Michael G. A1 - Niessner, R. T1 - Novel Aflatoxin derivatives and protein conjugates N2 - Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities. KW - Aflatoxin KW - Mycotoxin KW - Hapten KW - Protein conjugation KW - Immunogen KW - Antigen KW - Antibody PY - 2007 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-147572 UR - http://www.mdpi.org/molecules/papers/12030641.pdf UR - http://www.mdpi.org/molecules/papers/12030641sm.pdf DO - https://doi.org/10.3390/12030641 SN - 1420-3049 VL - 12 IS - 3 SP - 641 EP - 653 PB - MDPI CY - Basel AN - OPUS4-14757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ruibal, C. A1 - Gueidan, C. A1 - Selbmann, L. A1 - Gorbushina, Anna A1 - Crous, P.W. A1 - Groenewald, J.Z. A1 - Muggia, L. A1 - Grube, M. A1 - Isola, D. A1 - Schoch, C.L. A1 - Staley, J.T. A1 - Lutzoni, F. A1 - De Hoog, G.S. T1 - Phylogeny of rock-inhabiting fungi related to Dothideomycetes N2 - The class Dothideomycetes (along with Eurotiomycetes) includes numerous rock-inhabiting fungi (RIF), a group of ascomycetes that tolerates surprisingly well harsh conditions prevailing on rock surfaces. Despite their convergent morphology and physiology, RIF are phylogenetically highly diverse in Dothideomycetes. However, the positions of main groups of RIF in this class remain unclear due to the lack of a strong phylogenetic framework. Moreover, connections between rock-dwelling habit and other lifestyles found in Dothideomycetes such as plant pathogens, saprobes and lichen-forming fungi are still unexplored. Based on multigene phylogenetic analyses, we report that RIF belong to Capnodiales (particularly to the family Teratosphaeriaceae s.l.), Dothideales, Pleosporales, and Myriangiales, as well as some uncharacterised groups with affinities to Dothideomycetes. Moreover, one lineage consisting exclusively of RIF proved to be closely related to Arthoniomycetes, the sister class of Dothideomycetes. The broad phylogenetic amplitude of RIF in Dothideomycetes suggests that total species richness in this class remains underestimated. Composition of some RIF-rich lineages suggests that rock surfaces are reservoirs for plant-associated fungi or saprobes, although other data also agree with rocks as a primary substrate for ancient fungal lineages. According to the current sampling, long distance dispersal seems to be common for RIF. Dothideomycetes lineages comprising lichens also include RIF, suggesting a possible link between rock-dwelling habit and lichenisation. KW - Arthoniomycetes KW - Capnodiales KW - Dothideomycetes KW - Evolution KW - Extremotolerance KW - Multigene phylogeny KW - Rock-inhabiting fungi PY - 2009 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-219821 DO - https://doi.org/10.3114/sim.2009.64.06 SN - 0166-0616 VL - 64 IS - 1 SP - 123 EP - 133 PB - Centraalbureau voor Schimmelcultures CY - Utrecht, The Netherlands AN - OPUS4-21982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaebler, A. A1 - Moessinger, A. A1 - Goelden, F. A1 - Manabe, A. A1 - Goebel, M. A1 - Follmann, R. A1 - Koether, D. A1 - Modes, C. A1 - Kipka, A. A1 - Deckelmann, M. A1 - Rabe, Torsten A1 - Schulz, Bärbel A1 - Kuchenbecker, Petra A1 - Lapanik, A. A1 - Mueller, S. A1 - Haase, W. A1 - Jakoby, R. T1 - Liquid crystal-reconfigurable antenna concepts for space applications at microwave and millimeter waves N2 - Novel approaches of tunable devices for millimeter wave applications based on liquid crystal (LC) are presented. In the first part of the paper, a novel concept of a tunable LC phase shifter realized in Low Temperature Cofired Ceramics technology is shown while the second part of the paper deals with a tunable high-gain antenna based on an LC tunable reflectarray. The reflectarray features continuously beam scanning in between ±25°. Also first investigations on radiation hardness of LCs are carried out, indicating that LCs might be suitable for space applications. KW - Tunable antenna KW - Phase shifter KW - Liquid crystal KW - LTCC PY - 2009 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-194273 DO - https://doi.org/10.1155/2009/876989 SN - 1687-5877 VL - 2009 IS - Article ID 876989 SP - 1 EP - 7 PB - Hindawi Publishing Corporation CY - New York, NY, USA AN - OPUS4-19427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kannengießer, Thomas A1 - Kromm, Arne T1 - Formation of welding residual stresses in low transformation temperature (LTT) materials N2 - For the safety and cost efficiency of welded high-strength steel structures, precise knowledge of the level and distribution of welding- and cooling-specific stresses and residual stresses is essential, since they exert a decisive influence on strength, crack resistance, and finally on the bearable service load. This paper presents innovative filler materials, of which the phase transformation temperature was deliberately adjusted via the chemical composition. The transformation behaviour of these martensitic Low Transformation Temperature (LTT-) filler materials shows direct effects on the local residual stresses in the weld and the HAZ. These effects can purposefully be exploited to counteract the thermally induced shrinkage of the material and to produce significant compressive residual stresses in the weld. Comparative welding experiments were carried out on 690 MPa high-strength base materials using various LTT-filler materials. High energy synchrotron radiation was used for residual stress measurement. Particularly the use of high energy synchrotron radiation makes it possible to detect the residual stress condition fast without destruction of material. Thereby, residual stress depth gradients can be determined simultaneously without removing material. In steel, gradients of up to 150 µm can be resolved in such a way. Furthermore, the application of high energy radiation permits determination of residual stresses of any available residual austenite contents. Results show significant dependence of transformation temperatures on the resulting residual stress level and distribution. KW - Phase specific residual stresses KW - Phase transformation KW - Low transformation temperature filler wire KW - Energy dispersive diffraction KW - High strength steel PY - 2009 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-205909 DO - https://doi.org/10.1590/S0104-92242009000100009 SN - 0104-9224 SN - 1980-6973 VL - 14 IS - 1 SP - 74 EP - 81 PB - Associação Brasileira de Soldagem, ABS CY - Rio de Janeiro AN - OPUS4-20590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - In-situ-phase analysis using synchrotron radiation of low transformation temperature (LTT) welding material N2 - Cold cracking resistance is a relevant evaluation criterion for welded joints and affected by residual stresses which result from the welding procedure. Compressive residual stresses can thereby have a positive influence on preventing cracking. A unique possibility of generating compressive residual stresses already during the welding procedure is offered by the so-called Low Transformation Temperature (LTT) filler wires. Compared to conventional wires, these materials show decreased phase transformation temperatures which can work against the cooling-specific contraction. In consequence, distinct compressive residual stresses can be observed within the weld and adjacent areas. The strength of these fillers makes them potentially applicable to high-strength steel welding. Investigations were carried out to determine the phase transformation behaviour of different LTT-filler materials. Transformation temperatures were identified using Single Sensor Differential Thermal Analysis (SS-DTA). Additionally Synchrotron radiation was used to measure the transformation kinetics of all involved crystalline phases during heating and cooling of a simulated weld thermal cycle. KW - In-situ phase analysis KW - Energy dispersive diffraction KW - Phase transformation KW - Low Transformation Temperature filler wire PY - 2009 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-205922 DO - https://doi.org/10.1590/S0104-92242009000100010 SN - 0104-9224 SN - 1980-6973 VL - 14 IS - 1 SP - 82 EP - 88 PB - Associação Brasileira de Soldagem, ABS CY - Rio de Janeiro AN - OPUS4-20592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moreira, E.V. A1 - Rabello, J.M.B. A1 - Pereira, M.d.S. A1 - Lopes, R.T. A1 - Zscherpel, Uwe T1 - Digital radiography using digital detector arrays fulfills critical applications for offshore pipelines N2 - Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array) is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines. KW - Zerstörungsfreie Prüfung von Schweißnähten KW - Durchstrahlungsprüfung KW - Digitale Radiologie PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-225319 DO - https://doi.org/10.1155/2010/894643 SN - 1687-6172 VL - 2010 IS - Article ID 894643 SP - 1 EP - 7 PB - Hindawi Publ. CY - New York, NY, USA AN - OPUS4-22531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shokouhi, Parisa A1 - Zoëga, Andreas A1 - Wiggenhauser, Herbert T1 - Nondestructive investigation of stress-induced damage in concrete N2 - The changes in the sonic surface wave velocity of concrete under stress were investigated in this paper. Surface wave velocities at sonic frequency range were measured on a prismatic concrete specimen undergoing several cycles of uniaxial compression. The loading was applied (or removed) gradually in predefined small steps (stress-controlled). The surface wave velocity was measured at every load step during both loading and unloading phases. Acoustic Emission (AE) test was conducted simultaneously to monitor the microcracking activities at different levels of loading. It was found that the sonic surface wave velocity is highly stress dependent and the velocity-stress relationship follows a particular trend. The observed trend could be explained by a combination of acoustoelasticity and microcracking theories, each valid over a certain range of applied stresses. Having measured the velocities while unloading, when the material suffers no further damage, the effect of stress and damage could be differentiated. The slope of the velocity-stress curves over the elastic region was calculated for different load cycles. This quantity was normalized to yield a dimensionless nonlinear parameter. This parameter generally increases with the level of induced damage in concrete. KW - Nondestructive testing (NDT) KW - Surface wave velocity KW - Concrete KW - Acoustoelasticity KW - Microcracking PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-215943 UR - http://downloads.hindawi.com/journals/ace/2010/740189.pdf DO - https://doi.org/10.1155/2010/740189 SN - 1687-8094 SN - 1687-8086 VL - 2010 IS - Article ID 740189 SP - 1 EP - 9 PB - Hindawi Publ. Corp. CY - New York, NY, USA AN - OPUS4-21594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lück, S. A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Schmidt, V. T1 - Statistical analysis of tomographic reconstruction algorithms by morphological image characteristics N2 - We suggest a procedure for quantitative quality control of tomographic reconstruction algorithms. Our task-oriented evaluation focuses on the correct reproduction of phase boundary length and has thus a clear implication for morphological image analysis of tomographic data. Indirectly the method monitors accurate reproduction of a variety of locally defined critical image features within tomograms such as interface positions and microstructures, debonding, cracks and pores. Tomographic errors of such local nature are neglected if only global integral characteristics such as mean squared deviation are considered for the evaluation of an algorithm. The significance of differences in reconstruction quality between algorithms is assessed using a sample of independent random scenes to be reconstructed. These are generated by a Boolean model and thus exhibit a substantial stochastic variability with respect to image morphology. It is demonstrated that phase boundaries in standard reconstructions by filtered backprojection exhibit substantial errors. In the setting of our simulations, these could be significantly reduced by the use of the innovative reconstruction algorithm DIRECTT. KW - Tomography KW - Computed tomography KW - Reconstruction algorithm KW - Morphological image analysis KW - Phase boundary KW - Metrology KW - Non-destructive testing PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-210710 DO - https://doi.org/10.5566/ias.v29.p61-77 SN - 1580-3139 SN - 1854-5165 VL - 29 SP - 61 EP - 77 CY - Ljubljana, Slovenia AN - OPUS4-21071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lai Wai-Lok, Wallace A1 - Kind, Thomas A1 - Wiggenhauser, Herbert T1 - A study of concrete hydration and dielectric relaxation mechanism using ground penetrating radar and short-time fourier transform N2 - Ground penetrating radar (GPR) was used to characterize the frequency-dependent dielectric relaxation phenomena in ordinary Portland cement (OPC) hydration in concrete changing from fresh to hardened state. The study was experimented by measuring the changes of GPR A-scan waveforms over a period of 90 days, and processed the waveforms with short-time Fourier transform (STFT) in joint time-frequency analysis (JTFA) domain rather than a conventional time or frequency domain alone. The signals of the direct wave traveled at the concrete surface and the reflected wave from an embedded steel bar were transformed with STFT, in which the changes of peak frequency over ages were tracked. The peak frequencies were found to increase with ages and the patterns were found to match closely with primarily the well-known OPC hydration process and secondarily, the evaporation effect. The close match is contributed to the simultaneous effects converting free to bound water over time, on both conventional OPC hydration and dielectric relaxation mechanisms. KW - Soil water content KW - Wet soil KW - Microwave KW - Moisture KW - GPR KW - Dispersion PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-239723 DO - https://doi.org/10.1155/2010/317216 SN - 1687-6172 IS - Article ID 317216 SP - 1 EP - 14 PB - Hindawi Publ. CY - New York, NY, USA AN - OPUS4-23972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten T1 - Review on the functional determinants and durability of shape memory polymers N2 - Shape memory polymers (SMP) belong to the class of stimuli-responsive materials and have generated significant research interest. Their capability to retain an imposed, temporary shape and to recover the initial, permanent shape upon exposure to an external stimulus depends on the "functional determinants", which in simplistic terms, can be divided into structural/morphological and processing/environmental factors. The primary aim of the first part of this review is to reflect the knowledge about these fundamental relationships. In a next step, recent advances in shape memory polymer composites are summarized. In contrast to earlier reviews, studies on the impairment of shape memory properties through various factors, such as aging, compression and hibernation, lubricants, UV light and thermo-mechanical cycling, are extensively reviewed. Apart from summarizing the state-of-the-art in SMP research, recent progress is commented. KW - Shape memory polymer KW - Active polymer KW - Shape memory polymer composite KW - Shape memory properties KW - Functionality KW - Degradation KW - Aging KW - Functional determinants KW - Thermo-mechanical testing KW - Durability PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-217390 UR - http://www.mdpi.com/2073-4360/2/3/120/pdf DO - https://doi.org/10.3390/polym2030120 SN - 2073-4360 VL - 2 IS - 3 SP - 120 EP - 158 PB - MDPI CY - Basel AN - OPUS4-21739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard T1 - Phosphorus-based flame retardancy mechanisms - Old hat or a starting point for future development? N2 - Different kinds of additive and reactive flame retardants containing phosphorus are increasingly successful as halogen-free alternatives for various polymeric materials and applications. Phosphorus can act in the condensed phase by enhancing charring, yielding intumescence, or through inorganic glass formation; and in the gas phase through flame inhibition. Occurrence and efficiency depend, not only on the flame retardant itself, but also on its interaction with pyrolysing polymeric material and additives. Flame retardancy is sensitive to modification of the flame retardant, the use of synergists/adjuvants, and changes to the polymeric material. A detailed understanding facilitates the launch of tailored and targeted development. KW - Fire retardancy KW - Red phosphorus KW - Phosphate KW - Phosphonate KW - Phosphinate KW - Phosphine oxide KW - Flame inhibition KW - Charring KW - Intumescence PY - 2010 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-220368 DO - https://doi.org/10.3390/ma3104710 SN - 1996-1944 VL - 3 IS - 10 SP - 4710 EP - 4745 PB - MDPI CY - Basel AN - OPUS4-22036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasper, J. A1 - Hermanns, M. A1 - Bantz, C. A1 - Maskos, Michael A1 - Stauber, R. A1 - Pohl, C. A1 - Unger, R. E. A1 - Kirkpatrick, J.C. T1 - Inflammatory and cytotoxic responses of an alveolar-capillary coculture model to silica nanoparticles: comparison with conventional monocultures N2 - To date silica nanoparticles (SNPs) play an important role in modern technology and nanomedicine. SNPs are present in various materials (tyres, electrical and thermal insulation material, photovoltaic facilities). They are also used in products that are directly exposed to humans such as cosmetics or toothpaste. For that reason it is of great concern to evaluate the possible hazards of these engineered particles for human health. Attention should primarily be focussed on SNP effects on biological barriers. Accidentally released SNP could, for example, encounter the alveolar-capillary barrier by inhalation. In this study we examined the inflammatory and cytotoxic responses of monodisperse amorphous silica nanoparticles (aSNPs) of 30 nm in size on an in vitro coculture model mimicking the alveolar-capillary barrier and compared these to conventional monocultures. Methods Thus, the epithelial cell line, H441, and the endothelial cell line, ISO-HAS-1, were used in monoculture and in coculture on opposite sides of a filter membrane. Cytotoxicity was evaluated by the MTS assay, detection of membrane integrity (LDH release), and TER (Transepithelial Electrical Resistance) measurement. Additionally, parameters of inflammation (sICAM-1, IL-6 and IL-8 release) and apoptosis markers were investigated. Results Regarding toxic effects (viability, membrane integrity, TER) the coculture model was less sensitive to apical aSNP exposure than the conventional monocultures of the appropriate cells. On the other hand, the in vitro coculture model responded with the release of inflammatory markers in a much more sensitive fashion than the conventional monoculture. At concentrations that were 10-100fold less than the toxic concentrations the apically exposed coculture showed a release of IL-6 and IL-8 to the basolateral side. This may mimic the early inflammatory events that take place in the pulmonary alveoli after aSNP inhalation. Furthermore, a number of apoptosis markers belonging to the intrinsic pathway were upregulated in the coculture following aSNP treatment. Analysis of the individual markers indicated that the cells suffered from DNA damage, hypoxia and ER-stress. Conclusion We present evidence that our in vitro coculture model of the alveolar-capillary barrier is clearly advantageous compared to conventional monocultures in evaluating the extent of damage caused by hazardous material encountering the principle biological barrier in the lower respiratory tract. KW - Silica nanoparticles KW - Alveolar-capillary coculture model KW - Cytotoxicity PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-254217 DO - https://doi.org/10.1186/1743-8977-8-6 SN - 1743-8977 VL - 8 IS - 6 SP - 1 EP - 16(?) PB - BioMed Central CY - London AN - OPUS4-25421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tölle, Florian A1 - Gumenyuk, Andrey A1 - Gebhardt, Moritz Oliver A1 - Rethmeier, Michael T1 - Post-weld residual stress mitigation by scanning of a defocused laser beam N2 - High welding residual stresses can cause service life reducing consequences. Even though many processes have been developed to reduce these stresses, they are only applicable for wider welds and simple component geometries or are cost-intensive, respectively. The presented method uses a defocused beam after welding for heating the material regions on both sides of the weld. In this way, the welding stresses are decreased without contacting the surfaces using the available equipment. Different process parameters could be used depending on the component geometry and the laser power. The mechanism and the influence of the process parameters were investigated by FEM-simulation and experiments on S355J2+N steel and showed a stress reduction of about 73%. T2 - Lasers in Manufacturing 2011 - Proceedings of the Sixth International WLT Conference on Lasers in Manufacturing CY - Munich, Germany DA - 23.05.2011 KW - Residual stresses KW - Stress reduction KW - High energy beam welding KW - Post-weld heat treatment KW - Laser scanner optics PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-238482 DO - https://doi.org/10.1016/j.phpro.2011.03.052 SN - 1875-3892 VL - 12 IS - 1 SP - 410 EP - 418 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-23848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhlich, Paul A1 - Emmerling, Franziska A1 - Piechotta, Christian A1 - Nehls, Irene T1 - Methyl 3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydronaphthalene-2-carboxylate (AHTN-COOMe) N2 - Crystals of the title compound, C18H26O2, were grown from ethyl acetate. Due to the racemic precursor, the title compound is also obtained as a racemate. Disorder was observed during structure refinement, originating from two possible half-chair conformations of the non-aromatic ring. The disorder was refined by introducing split positions in the cyclo-hexane ring regarding the two possible R and S-enantiomers at the chiral CH group [ratio 0.744 (3):0.256 (3)]. The crystal structure features pairs of inversion-related molecules connected by pairs of non-classical C–H···O hydrogen bonds. KW - AHTN KW - Tonalide KW - Cyclic musk KW - AHTN-COOMe KW - Disinfection by-product KW - Esterification PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-232769 DO - https://doi.org/10.1107/S1600536811002601 SN - 1600-5368 VL - E67 IS - 2 SP - o485, sup-1 EP - sup-11 PB - Munksgaard CY - Copenhagen AN - OPUS4-23276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Walter, Astrid A1 - Panne, Ulrich A1 - Weller, Michael G. T1 - A novel immunoreagent for the specific and sensitive detection of the explosive triacetone triperoxide (TATP) N2 - Triacetone triperoxide (TATP) is a primary explosive, which was used in various terrorist attacks in the past. For the development of biosensors, immunochemical µ-TAS, electronic noses, immunological test kits, or test strips, the availability of antibodies of high quality is crucial. Recently, we presented the successful immunization of mice, based on the design, synthesis, and conjugation of a novel TATP derivative. Here, the long-term immunization of rabbits is shown, which resulted in antibodies of extreme selectivity and more than 1,000 times better affinity in relation to the antibodies from mice. Detection limits below 10 ng L-1 (water) were achieved. The working range covers more than four decades, calculated from a precision profile. The cross-reactivity tests revealed an extraordinary selectivity of the antibodies—not a single compound could be identified as a relevant cross-reactant. The presented immunoreagent might be a major step for the development of highly sensitive and selective TATP detectors particularly for security applications. KW - Organic peroxides KW - Terrorism KW - Biosensor development PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-240291 UR - http://www.mdpi.com/2079-6374/1/3/93 DO - https://doi.org/10.3390/bios1030093 SN - 2079-6374 VL - 1 IS - 3 SP - 93 EP - 106 PB - MDPI CY - Basel AN - OPUS4-24029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pelkner, Matthias A1 - Neubauer, Andreas A1 - Reimund, Verena A1 - Kreutzbruck, Marc T1 - Routes for GMR-sensor design in non-destructive testing N2 - GMR sensors are widely used in many industrial segments such as information technology, automotive, automation and production, and safety applications. Each area requires an adaption of the sensor arrangement in terms of size adaption and alignment with respect to the field source involved. This paper deals with an analysis of geometric sensor parameters and the arrangement of GMR sensors providing a design roadmap for non-destructive testing (NDT) applications. For this purpose we use an analytical model simulating the magnetic flux leakage (MFL) distribution of surface breaking defects and investigate the flux leakage signal as a function of various sensor parameters. Our calculations show both the influence of sensor length and height and that when detecting the magnetic flux leakage of µm sized defects a gradiometer base line of 250 µm leads to a signal strength loss of less than 10% in comparison with a magnetometer response. To validate the simulation results we finally performed measurements with a GMR magnetometer sensor on a test plate with artificial µm-range cracks. The differences between simulation and measurement are below 6%. We report on the routes for a GMR gradiometer design as a basis for the fabrication of NDT-adapted sensor arrays. The results are also helpful for the use of GMR in other application when it comes to measure positions, lengths, angles or electrical currents. KW - Giant magneto resistance KW - Non-destructive testing KW - Magnetic flux leakage KW - Sensor array PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-271325 DO - https://doi.org/10.3390/s120912169 SN - 1424-8220 VL - 12 IS - 9 SP - 12169 EP - 12183 PB - MDPI CY - Basel AN - OPUS4-27132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiegner, Katharina A1 - Hahn, Oliver A1 - Horn, Wolfgang A1 - Farke, M. A1 - Kalus, Sabine A1 - Nohr, Michael A1 - Jann, Oliver T1 - Determination of formic and acetic acid emissions in indoor air or from building products N2 - Several construction and building materials, including wood, glue and coatings, are possible sources of very volatile organic compounds (VVOCs) and volatile organic compounds (VOCs) like formic and acetic acid. Due to very high air tightness and very low air exchange rates in new buildings concentrations of these harmful substances can increase considerably. To minimize the risk, emissions from building products should be identified and quantified. With the common standard method, this means Tenax® sampling followed by thermal desorption and GC-MS analysis, these acids could not be detected sufficiently. The aim oft this study is the comparison of two different methods for the determination of acetic and formic acid. The sampling of method one, which is usually used for identification and quantification of VOCs, is done in accordance with ISO 16000-6 and ISO 16017-1 on Carbotrap® 202 multi-bed thermal desorption tube by subsequent identification and quantification with GC-MS. Method two is based on sampling on 2,4-dinitrophenylhydrazine (DNPH) cartridges, derivatisation, elution, identification and quantification of the derivatives with LC-MS/MS (liquid chromatography – mass spectrometry/mass spectrometry). N2 - Viele Konstruktions- und Baumaterialien, wie Holz, Kleber und Anstriche, sind mögliche Quellen für leicht flüchtige organische Verbindungen (VVOC) und flüchtige organische Verbindungen (VOC), wie Ameisen- und Essigsäure. Bedingt durch die hohe Dichtigkeit und den damit verbundenen niedrigen Luftwechsel in neuen Gebäuden können die Konzentrationen dieser gesundheitsgefährdenden Substanzen beträchtlich ansteigen. Um das Risiko zu minimieren, sollen Emissionen aus Bauprodukten identifiziert und quantifiziert werden. Mit der üblichen Standardmethode, die auf einer Luftprobenahme auf Tenax® und anschließender Analyse mittels GC-MS basiert, können diese Säuren nicht ausreichend detektiert werden. Ziel dieser Arbeit ist der Vergleich von zwei unterschiedlichen Methoden zur Bestimmung von Essig- und Ameisensäure. Die Luftprobenahme der ersten Methode, die üblicherweise zur Identifizierung und Quantifizierung von VOC genutzt wird, wurde gemäß ISO 16000-6 and ISO 16017-1 auf Carbotrap® 202, ein mit mehreren Adsorbentien gepacktes Thermodesorptionsrohr, mit anschließender Identifikation und Quantifizierung mittels GC-MS durchgeführt. Die zweite Methode basiert auf einer Luftprobenahme mittels 2,4-Dinitrophenylhydrazin-(DNPH)-Kartuschen, Derivatisierung, Elution, Identifikation und Quantifizierung der Derivate mit LC-MS/MS (Flüssigkeitschromatographie – Massenspektometrie/Massenspektometrie). KW - Formic acid KW - Acetic acid KW - VVOCs KW - Air sampling KW - DNPH PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-255911 UR - http://www.gefahrstoffe.de/gest/article.php?data[article_id]=65887 SN - 0949-8036 SN - 0039-0771 SN - 1436-4891 VL - 72 IS - 3 SP - 84 EP - 88 PB - Springer-VDI-Verlag CY - Düsseldorf AN - OPUS4-25591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weller, Michael G. T1 - A unifying review of bioassay-guided fractionation, effect-directed analysis and related techniques N2 - The success of modern methods in analytical chemistry sometimes obscures the problem that the ever increasing amount of analytical data does not necessarily give more insight of practical relevance. As alternative approaches, toxicity- and bioactivity-based assays can deliver valuable information about biological effects of complex materials in humans, other species or even ecosystems. However, the observed effects often cannot be clearly assigned to specific chemical compounds. In these cases, the establishment of an unambiguous cause-effect relationship is not possible. Effect-directed analysis tries to interconnect instrumental analytical techniques with a biological/biochemical entity, which identifies or isolates substances of biological relevance. Successful application has been demonstrated in many fields, either as proof-of-principle studies or even for complex samples. This review discusses the different approaches, advantages and limitations and finally shows some practical examples. The broad emergence of effect-directed analytical concepts might lead to a true paradigm shift in analytical chemistry, away from ever growing lists of chemical compounds. The connection of biological effects with the identification and quantification of molecular entities leads to relevant answers to many real life questions. KW - Toxicity KW - Drug discovery KW - Natural products KW - Environmental analysis KW - Lead identification PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-262960 DO - https://doi.org/10.3390/s120709181 SN - 1424-8220 VL - 12 IS - 7 SP - 9181 EP - 9209 PB - MDPI CY - Basel AN - OPUS4-26296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhlich, Paul A1 - Emmerling, Franziska A1 - Kraus, Werner A1 - Nehls, Irene A1 - Piechotta, Christian T1 - 1-(4-bromo-3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)ethan-1-one: a precursor for phase-I metabolite of AHTN N2 - The title compound, C18H25BrO, crystallized as a racemate with four independent molecules in the asymmetric unit. In the crystal, three of these four molecules are linked via C-Br...Br-C halogen bonds [Br...Br = 3.662 (2) and 3.652 (2) Å], forming dimers. PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-279935 DO - https://doi.org/10.1107/S1600536813006934 SN - 1600-5368 VL - 69 IS - 4 SP - o545, sup-1 EP - sup-17 PB - Munksgaard CY - Copenhagen AN - OPUS4-27993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schukar, Vivien A1 - Kusche, Nadine A1 - Kalinka, Gerhard A1 - Habel, Wolfgang T1 - Field deployable fiber bragg grating strain patch for long-term stable health monitoring applications N2 - A fiber Bragg grating (FBG) strain patch specially adapted for long-term and high-strain applications has been developed and characterized. The design concept for the patch is based on a glass-fiber reinforced plastic (gfrp) carrier material. The developed concept for the FBG integration into the carrier material was derived from reliable integration procedure of FBG sensors into composite structures. The patches' temperature sensitivity, strain gauge factor, fiber–matrix interface adhesion and fatigue behavior were characterized. As a result, FBG strain patches with linear temperature and strain behavior, as well as excellent fatigue resistance, were developed and can be used as part of a monitoring system for advanced composite materials in aerospace structures or wind turbine power plants. KW - Fiber Bragg grating KW - Patch KW - Strain gauge factor KW - Temperature sensitivity KW - Push-out test KW - Validation KW - Fatigue behavior PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-276271 DO - https://doi.org/10.3390/app3010039 SN - 2076-3417 VL - 3 IS - 1 SP - 39 EP - 54 PB - MDPI CY - Basel AN - OPUS4-27627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -