TY - JOUR A1 - Lorenz, S. A1 - Kannengießer, Thomas A1 - Posch, G. T1 - Suitability of high-alloyed flux-cored wire electrodes for laser-GMA hybrid welding N2 - The object of this research project related to investigations into the qualification of flux-cored wire electrodes for the laser-GMA hybrid welding of high-alloyed steels. Because of its annular metal shell and the powdery filling, this type of wire electrode permits stable, low-spatter metal transfer comparable with that in the spray arc, particularly in the upper range of the attainable deposition rates. In contrast with this, controlled metal transfer during the deposition of solid wire electrodes is achieved using pulsed arc technology. When these filler materials are welded, the properties specific to the material and to the process have a significant influence on the weld metallurgy as well as on the process stability. Tests were carried out on the AISI 403L (X2CrNi1911) high-alloyed base material in order to investigate the transferability of the attainable material properties from GMA welding to laser-GMA hybrid welding. Four wire electrodes were used according to DIN EN 12072 and DIN EN ISO 17633: a T 19 9 L P M 1 rutile fluxcored wire designed specifically for welding in position, a T 19 9 L R M (C) 3 rutile flux-cored wire suitable for welding in the flat position, a T 19 9 L M M 1 metal-powder flux-cored wire as well as a G 19 9 L Si solid wire. KW - Welding KW - Laser GMA hybrid welding PY - 2012 SN - 1612-3433 VL - 11 IS - 3 SP - 181 EP - 187 PB - DVS - German Welding Society CY - Düsseldorf AN - OPUS4-26298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lerena, P. A1 - Auerkari, Pertti A1 - Knaust, Christian A1 - Vela-Wallenschus, Iris A1 - Krause, U. T1 - Approaches towards a generic methodology for storage of hazardous energy carriers and waste products N2 - Energy carriers – either conventional or 'new' ones – have to be provided in large amounts to meet the requirements of permanent availability and reliable supply of electricity. Depending on their state of aggregation, energy carriers are either stored in large masses (if solid or liquid) or at elevated pressures (if gaseous). Both impose the hazard of large-scale fire, in the latter case additionally the danger of explosion or unintended release. Very similar hazards occur for wastes. Solid wastes are present in large masses and only a small part is recycled. Most of the solid wastes are used in energy conversion. The main gaseous waste is CO2. During capturing also the hazard of unintended release exists. In this article, existing approaches for safe storage and fire prevention are discussed and a generic methodology is outlined. This methodology consists of the following steps: - gaining knowledge about the behaviour of the material stored (reactivity, thermal stability, etc.), - assessing the environmental conditions for the storage site (neighbourhood, safety distances, etc.), - assessment of prospective consequences of an incident and - development of individual loss prevention conceptions. All steps require both experimental testing and theoretical considerations about accident scenarios as integral parts of the methodology. KW - Storage KW - Hazardous materials KW - Energy carriers PY - 2013 DO - https://doi.org/10.1080/13669877.2012.729524 SN - 1366-9877 SN - 1466-4461 N1 - Geburtsname von Vela-Wallenschus, Iris: Vela, I. - Birth name of Vela-Wallenschus, Iris: Vela, I. VL - 16 IS - 3-4 SP - 433 EP - 445 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-26882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kloß, Heinz A1 - Österle, Werner T1 - Charakterisierung des mechanischen Reibungs- und Verschleißverhaltens von Werkstoffen mittels Simulationsrechnungen (Methode der beweglichen zellularen Automaten) und analytischer Modelle N2 - Der mechanische Verschleiß ist ein Deformationsprozeß bei dem Verschleißteilchen durch Bruchvorgänge erzeugt werden. Hierbei verursachen Normal- und Tangentialkräfte elastische und plastische Deformationen, die zur Erzeugen von Rissen und zur Bildung loser Verschleißteilchen durch Brüche führen. In Abhängigkeit von den Beanspruchungsbedingungen, den mechanischen und thermischen Eigenschaften der Werkstoffe und der Kontaktgeometrie wird das Reibungs- und Verschleißverhalten wesentlich durch die sich bildende mechanische Mischschicht als dritter Körper zwischen den sich berührenden Werkstoffoberflächen bestimmt. Am Beispiel von Simulationsrechnungen mit der Methode der beweglichen zellularen Automaten (bzA) werden das Bildungs- und Transportverhalten von Verschleißteilchen dargestellt und Zusammenhänge zum zeitlichen Verschleißverlauf (Inkubationsphase, Einlaufverschleiß, stationärer Verschleiß) aufgezeigt. N2 - Mechanical wear “is a deformation process producing wear particles by some mechanism of fracture mechanics”. In the process normal and tangential (shearing) forces cause elastic and plastic deformations, generate cracks and form loose wear particles by fracture. Depending on the working conditions, the material properties and the real contact Situation (topography), a third body is formed as a mechanically mixed layer, which determines a different running-in and steady-state wear behaviour. For the approach represented here, 2D MCA Simulation results will be described by empirical equations, which are related to the incubation time (period without wear) and the following running-in and steady-state wear rates. T2 - 53. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß CY - Göttingen, Germany DA - 24.09.2012 PY - 2012 SN - 978-3-00-039201-6 VL - II SP - 4/1 EP - 4/11 CY - Aachen AN - OPUS4-26733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Komann, Steffen A1 - Droste, Bernhard A1 - Gröke, Carsten T1 - Verpackungen Bestandsaufnahme - Pflichten und Vorschriften bei schwach radioaktiven Stoffen N2 - Transportverpackungen für schwach radioaktive Stoffe benötigen keine behördliche Bauartprüfung oder Zulassung. Aber sowohl Hersteller als auch Absender und Verwender müssen etliche Pflichten erfüllen. PY - 2012 SN - 0944-6117 IS - 6 SP - 20 EP - 25 PB - Vogel CY - München AN - OPUS4-26362 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang ED - Boller, C. T1 - Advances in developing standards for fibre-optic sensors N2 - Fibre optic sensors provide a great potential in different industrial as well as research fields. They are always then increasingly used if special requirements avoid the application of conventional electrical sensors. The scientific background for optical fibre sensors is well developed; however, not all users are already convinced that fibre optic sensors enable long-term stable function under harsh environmental conditions. There are still some restrictions with respect to long-term reliable use: first, some sensor products available on the market are sometimes not appropriately characterized and described. Second, application procedures are not always well validated due to a lack of understanding the mechanical, physical or chemical issues in the interface zone between sensor and measuring object. Industrial users therefore need standardized description of the sensor system performance, recommendations what aspects have to be considered for reliable application and operation of sensors, and finally how to handle the application of sensors under possibly harsh environmental conditions. Technical rules must be provided. First guidelines for the appropriate specification and use of fibre optic sensors have been developed and published. Several European and international activities have been launched to push the development of further standards for special applications. The paper informs about successful standardization activities. Worldwide running relevant guideline activities are presented. An outlook on important research activities to come to substantiated statements in standards is given. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 KW - Standardization KW - Fibre-optic sensors KW - Validation KW - Reliability KW - Calibration PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-274953 SN - 978-3-940283-41-2 IS - Tu.4.C.2 SP - 1 EP - 9 CY - Berlin AN - OPUS4-27495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knaust, Christian A1 - Rogge, Andreas ED - Lönnermark, A. ED - Ingason, H. T1 - Prediction of the temperature evolution in a tunnel construction in case of fire, by coupling the temperature-dependent heat transfer mechanisms inside the structural components and at their surface N2 - The thermal and mechanical behavior of structural components exposed to fire depends essentially on the time evolution of component temperature, the characteristic course of the fire incident and the duration of exposure to fire. The design of the components is usually based on standardized or projectbased temperature-time curves. Based on experience, analysis and experimental investigations, numerous temperature-time curves have been developed nationally and internationally for the Simulation of fires. Currently, there are no uniform standardized fire curves available for the design of tunnel components, The different assumptions made for the temperature-time curve in each country lead inevitably to different designs of components. Only at a national level, if any, it is regulated which temperature-time curves are to be applied for the different fire incidents and tunnel types (e.g. in Switzerland). For special projects that are not covered by national Standards, it is a difficult task for the projectdesigners to develop a suitable fire curve that enables the dimensioning of components ensuring both security and economic feasibility. Since at the moment there are no common European regulations in this respect, it can be even more problematic for the project designers if a tunnel project involves the security interests of different countries. Based on Computational Fluid Dynamics (CFD) methods, now it is possible for scientists and researchers to develop appropriate fire curves and to make them available for the project planners. Numerical and experimental methods can be used for investigations in fluid mechanics and structural analysis to predict the component behavior under fire exposure (fire resistance, spalling etc.). Current technology allows the coupling of the heat transfer mechanisms in case of fire within the structural components and at their surface by means of CFD. For a given fire scenario (e.g. fire load, smoke exhaust Systems, Ventilation conditions) and tunnel design, not only safety parameters such as smoke layer height and visibility but also the influences of heat storage in the component layers of the tunnel structure can be predicted taking into account the temperature dependent material properties in the course of time. As a result, it is possible to provide the structural project designers with useful information about the temperature-time characteristics of the structure. T2 - 5th International Symposium on tunnel safety and security CY - New York, USA DA - 14.03.2012 KW - Fire KW - High tmeperature fire loads KW - Component temperatures KW - Wall temperatures KW - Concrete KW - High temperature behavior KW - Thermal properties KW - Computational Fluid Dynamics KW - CFD PY - 2012 SN - 978-91-87017-26-1 SN - 0284-5172 VL - 2 SP - 753 EP - 756 AN - OPUS4-28067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - On the early-age behavior of zero-slump concrete N2 - This paper presents experimental investigations and analyses on the early-age-behavior of zero-slump concrete, such as compaction behavior and green-strength. First, the influence of the granulometric properties of the fines is discussed in detail. For this purpose, the early-age behavior of two different fines (quartz flour and fly ash) is investigated by means of the intensive compaction test (IC-test). The tests on the influence of the fines focus on effects caused by differences in the particle shape and the use of a plasticizing admixture. The conducted tests on the compaction behavior of the fines and their corresponding green-strength are extended to continuously graded granular mixes. Here, the influence of optimized particle packing on the early-age behavior is presented and a comparison on the basis of the aforementioned quartz flour and fly ash is made. In this consideration, experimental investigations on the early-age behavior of a zero-slump concrete mix and possible effects on the hardened concrete properties are included. KW - Zero-slump concrete (A) KW - Green-strength (C) KW - Compaction behavior (A) KW - Intensive compaction test (C) PY - 2012 DO - https://doi.org/10.1016/j.cemconres.2011.11.007 SN - 0008-8846 SN - 1873-3948 VL - 42 IS - 3 SP - 501 EP - 510 PB - Pergamon Press CY - New York, NY AN - OPUS4-26078 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinze, Christoph A1 - Schwenk, Christopher A1 - Rethmeier, Michael T1 - Numerical calculation of residual stress development of multi-pass gas metal arc welding N2 - In various applications, welding-induced residual stresses have a substantial impact on the integrity of welded constructions. Tensile residual stress can promote stress-corrosion cracking, brittle fracture, and reduces the fatigue life in service, as well as influences component design due to critical stress concentrations within the component. In the present paper, a six bead multi-pass gas metal arc weld of 20 mm thick structural steel S355J2+N is experimentally and numerically investigated. The studies include transient 2D and 3D numerical calculations which consider temperature-dependent material properties, phase transformations, 'thermal' tempering, transformation plasticity, volume change due to phase transformation, an elastic–plastic material model, and isotropic strain hardening. The experimentally determined and calculated residual stresses are in a good agreement. Furthermore, the influence of the preheat and interpass temperature on welding-induced residual stresses is shown in the present investigation. KW - Welding simulation KW - Gas metal arc welding KW - Welding-induced residual stress KW - Multi-pass welding KW - Sensitivity analysis PY - 2012 DO - https://doi.org/10.1016/j.jcsr.2011.08.011 SN - 0143-974x VL - 72 SP - 12 EP - 19 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-25629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tuaev, X. A1 - Paraknowitsch, J.P. A1 - Illgen, René A1 - Thomas, A. A1 - Strasser, P. T1 - Nitrogen-doped coatings on carbon nanotubes and their stabilizing effect on Pt nanoparticles N2 - A homogeneous coating of nitrogen-doped carbon on carbon nanotubes is performed using ionic liquids. The N-doped material is employed as a support for nanoparticles. Electrochemical degradation behavior is monitored in situ and compared to an unmodified material. The strongly enhanced stability is explained on the basis of a Pt–nitrogen interaction. PY - 2012 DO - https://doi.org/10.1039/c2cp40760d SN - 1463-9076 SN - 1463-9084 VL - 14 IS - 18 SP - 6444 EP - 6447 PB - The Royal Soc. of Chemistry CY - Cambridge AN - OPUS4-25787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinze, Christoph A1 - Schwenk, Christopher A1 - Rethmeier, Michael T1 - The effect of tack welding on numerically calculated welding-induced distortion N2 - A single-layer pulsed gas metal arc weld of structural steel S355J2+N with a thickness of 5 mm is experimentally and numerically investigated. Two tack welds are considered in the numerical simulation into two different ways. First, the tack welds are represented by elements belonging to the initial material. This implies that the 'tack weld material' was not exposed to any thermal load or phase transformation before actual welding was performed. The weld seam is shortened and there is an influence on the stiffness of the whole structure affecting the calculation result. Secondly, the tack welds were simulated as conducted in the experimental welding procedure. The cases considering tack welding are compared to a simulation neglecting tack welding and to the experimental results. The influence of tack welds on the calculated welding-induced distortion is clarified and a contribution to an improved simulation-based prediction of welding-induced distortion is possible by modeling tack welding according to the realistic fabrication procedure. KW - Welding simulation KW - Welding-induced distortion KW - Gas metal arc welding KW - Tack welding PY - 2012 DO - https://doi.org/10.1016/j.jmatprotec.2011.09.016 SN - 0924-0136 SN - 1873-4774 VL - 212 IS - 1 SP - 308 EP - 314 PB - Elsevier CY - Amsterdam AN - OPUS4-24820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuka, K. A1 - Illerhaus, Bernhard A1 - Fritsch, G. A1 - Joschko, M. A1 - Rogasik, H. A1 - Paschen, M. A1 - Schulz, H. A1 - Seyfarth, M. T1 - Maschinelle Entnahme ungestörter Bodenprobensäulen für die Röntgen-Computertomographie N2 - Haben Sie sich schon einmal überlegt, was unter Ihren Füßen geschieht, wenn Sie über eine Wiese gehen? Könnten Sie beschreiben, wie es im Boden aussieht? Wie ist die Struktur des Bodens, wie breiten sich darin die Wurzeln der Pflanzen aus und wie ist die Wasserverteilung im Porenraum, welche die Umsatzprozesse im Boden bestimmt? Diese Fragen können Sie beantworten, wenn sie die Möglichkeit nutzen, den Boden mittels Computertomographie visuell darzustellen und quantitativ zu analysieren. Dazu müssen Sie aber zunächst nicht nur eine Probe, sondern statistisch relevant viele Proben aus dem Boden entnehmen. Eine Maschine zur zerstörungsfreien Bodenprobenahme ist notwendig. Wir beschreiben hier den Aufbau und den Einsatz eines solchen Gerätes und zeigen erste dadurch gewonnene Makro- & Mikro-Computertomographiebilder. KW - Zerstörungsfreie Bodenproben KW - Computertomographie PY - 2012 SN - 1616-069X SN - 0948-5112 VL - 129 SP - 42 EP - 46 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung CY - Berlin AN - OPUS4-25935 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witte, Julien A1 - Treutler, Kai A1 - Schroepfer, Dirk A1 - Kannengiesser, Thomas A1 - Wesling, Volker T1 - Influence of microstructure on the machinability and surface integrity of additively manufactured iron aluminides N2 - The increasing global focus on energy and resource efficiency has stimulated a growing interest in additive manufacturing. AM offers economic advantages and enables an efficient use of materials. However, AM components often require subsequent mechanical post-processing, such as machining (e.g., milling), to achieve the final contours or surfaces. This is a particular challenge due to the heterogeneous and anisotropic nature of AM structures, which affect machining and the resulting component properties. High-performance materials such as iron aluminide represent a promising alternative to conventional high-temperature materials with a significant economic advantage. However, the strength and hardness properties, which are advantageous for applications in highly stressed lightweight components, pose a challenge for economical machining in addition to the AM microstructure properties. The difficult-to-cut material causes accelerated tool wear and insufficient surface quality. This study shows that crack-free additive manufacturing of the three-component system of iron-nickel-aluminum is possible, and advantages in terms of machinability compared to FeAl-AM components are achieved. The more homogeneous microstructure leads to a reduction in cutting forces, with positive effects on the machinability and optimized surface integrity. Ultrasonic assisted milling (USAM) offers great potential to address the major challenges posed by difficult-to-cut materials and additively manufactured weld structures. Therefore, this study focuses on assessing the transferability of previous positive results by USAM to the selected iron aluminide alloys. The machinability of the aluminides is analyzed by varying significant influencing variables in finish milling experiments and evaluated in terms of the loads on the tool and the resulting surface integrity. KW - Iron aluminide KW - Additive manufacturing KW - Machinability KW - Surface integrity KW - Ultrasonic-assisted milling process PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656993 DO - https://doi.org/10.1007/s40194-026-02382-6 SN - 0043-2288 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-65699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Vogl, Jochen A1 - Pritzkow, Wolfgang ED - Vanhaecke, F. ED - Degryse, P. T1 - Reference materials in isotopic analysis N2 - The production of isotopic reference materials (IRMs), which started in the 1960s, has stagnated during the last 15 years. On the other hand, the need for IRMs increased strongly with upcoming ICP-MS techniques, especially with MC instruments, in the beginning of the millennium. In parallel, the precision of the isotope amount ratio determinations reached a level which is beyond that of IRMs certified relying on synthetic isotope mixtures. Additionally, the number of elements for which IRMs are required has increased. This difference between the users’ needs and the limitations of current IRMs can only be solved by providing IRMs defining a δ-scale for each element of interest. Such δ-RMs should be produced as solutions to avoid any complications with homogeneity issues. Whenever possible, isotope amount fractions should be provided additionally, even if the uncertainties are not sufficient for cutting-edge research on isotopic variations. Research should also focus on ways to provide isotope amount fractions with lower uncertainties. For the coming years, around 27 elements have been selected by user communities as "of interest” in this context. These elements are of interest to geo- and cosmochemists, and also to scientists working in the fields of human nutrition, human medicine, veterinary medicine, and food traceability. For 18 elements, such as Pb and U, IRMs or δ-RMs are available, provided as a solution or a solid material with sufficient homogeneity. Nevertheless, in some cases further materials are necessary, because the number of units is too small or the materials are too expensive to be widely accepted by users. At BAM, IRMs and δ-RMs will be produced according to the requirements mentioned above. NIST has also started a program to produce new RMs for δ-values. As discussed at the latest meeting of the IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) in July 2009 in Vienna, these activities will be supported by IUPAC. KW - ICPMS KW - IRM KW - Reference materials KW - Delta reference materials PY - 2012 SN - 978-3-527-32896-3 SN - 978-3-527-65048-4 DO - https://doi.org/10.1002/9783527650484.ch6 SP - 139 EP - 163 PB - Wiley-VCH CY - Weinheim AN - OPUS4-26102 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tannenberg, Robert A1 - Tscheuschner, Georg A1 - Raab, Christopher A1 - Flemig, Sabine A1 - Döring, Sarah A1 - Ponader, Marco A1 - Thurmann, Melinda A1 - Paul, Martin A1 - Weller, Michael G. T1 - Simplified Sample Preparation and Lateral Flow Immunoassay for the Detection of Plant Viruses N2 - Lateral flow immunoassays (LFAs) are widely used for on-site testing; however, their use for the rapid detection of plant viruses in the field is often limited by inconvenient sample preparation. Here, we present a new sampling method and a simplified dipstick LFA format for the detection and monitoring of cowpea chlorotic mottle virus (CCMV) as a model plant pathogen. The assay employs a monoclonal mouse antibody for capture and a poly-clonal rabbit antibody conjugated to 80 nm gold nanoparticles for detection. Conventional sample and conjugate pads are omitted, allowing the test strips to be dipped directly into wells containing plant extract and antibody–gold conjugate. No plastic casing was required, which could lead to a reduction in waste. It was shown that CCMV concentrations as low as 3.5 µg/L or 350 pg per sample could be reliably detected in 15 min. Specificity tests confirmed that other plant viruses, cowpea mosaic virus (CPMV) and tobacco mosaic virus (TMV), did not produce false-positive results. In addition, we describe a new method for on-site sampling using a manual punch and a syringe equipped with a frit. This step combines grinding the sample, extraction, filtration, and reconstitution and mixing of the antibody-gold conjugate, enabling the analysis of punched leaf disks without laboratory equipment. When applied to CCMV-infected cowpea plants, the assay revealed systemic infection before visual symptoms became apparent. This work demonstrates that simplified LFAs combined with innovative sampling techniques can provide sensitive, specific, and rapid diagnostics for crop monitoring and support early intervention strategies in agriculture. N2 - Lateral-Flow-Immunoassays (LFAs) werden häufig für Vor-Ort-Tests eingesetzt; ihr Einsatz zum schnellen Nachweis von Pflanzenviren im Feld wird jedoch oft durch eine umständliche Probenvorbereitung eingeschränkt. Hier stellen wir eine neue Probenahmemethode und ein vereinfachtes Dipstick-LFA-Format zum Nachweis und zur Überwachung des Cowpea Chlorotic Mottle Virus (CCMV) als Modellpflanzenpathogen vor. Der Test verwendet einen monoklonalen Maus-Antikörper zur Bindung und einen polyklonalen Kaninchen-Antikörper, der an 80-nm-Goldnanopartikel konjugiert ist, zum Nachweis. Herkömmliche Proben- und Konjugatpads entfallen, sodass die Teststreifen direkt in Vertiefungen getaucht werden können, die Pflanzenextrakt und das Antikörper-Gold-Konjugat enthalten. Es ist keine Kunststoffhülle erforderlich, was zu einer Reduzierung des Abfallaufkommens führen könnte. Es zeigte sich, dass CCMV-Konzentrationen von nur 3,5 µg/L oder 350 pg pro Probe innerhalb von 15 Minuten zuverlässig nachgewiesen werden konnten. Spezifitätstests bestätigten, dass andere Pflanzenviren, das Cowpea Mosaic Virus (CPMV) und das Tobacco Mosaic Virus (TMV), keine falsch-positiven Ergebnisse lieferten. Darüber hinaus beschreiben wir eine neue Methode zur Probenahme vor Ort unter Verwendung eines manuellen Lochers und einer mit einer Fritte ausgestatteten Spritze. Dieser Schritt kombiniert das Zerkleinern der Probe, die Extraktion, die Filtration sowie die Rekonstitution und das Mischen des Antikörper-Gold-Konjugats und ermöglicht so die Analyse der ausgestanzten Blattscheiben ohne Laborausrüstung. Bei der Anwendung an mit CCMV infizierten Augenbohnenpflanzen zeigte der Assay eine systemische Infektion, bevor visuelle Symptome erkennbar wurden. Diese Arbeit zeigt, dass vereinfachte LFAs in Kombination mit innovativen Probenahmetechniken eine sensitive, spezifische und schnelle Diagnostik für die Pflanzenüberwachung bieten und Strategien zur frühzeitigen Intervention in der Landwirtschaft unterstützen können. KW - Point-of-care diagnostics KW - Dipstick immunoassay KW - Pre-symptomatic detection KW - Precision agriculture KW - Integrated pest management KW - Crop health monitoring PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657039 DO - https://doi.org/10.3390/bios16020100 SN - 2079-6374 VL - 16 IS - 2 SP - 1 EP - 16 PB - MDPI AG CY - Basle, Switzerland AN - OPUS4-65703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachsmuth, Janne A1 - Malikoutsakis, M. A1 - Savaidis, G. A1 - Savaidis, A. A1 - Bohse, Jürgen T1 - Corrosion and fatigue crack monitoring by means of acoustic emission for application in transportation means N2 - Corrosion damages and fatigue cracks are the main causes of structural failures in vessels and transport products. Acoustic emission is suggested as an alternative to the conventional inspection processes enabling continuous health monitoring of the structures. Comprehensive finite element analyses have been performed on the example of a 3-compartment road tanker taking the corresponding ADR design loads into account. The numerical results reveal various weld joints as the structure’s failure-critical hot spots. Welded plates made of fine grain steel were stressed by corrosion and fatigue. Damage development in the material was measured and analyzed by acoustic emission testing. It is shown that the different degradation mechanisms, corrosion and fatigue crack growth in welded areas, can be reliably detected by acoustic emission. In addition, principal differences of the acoustic emission signals depending on the degradation mechanism are also explored. KW - Acoustic emission KW - Health monitoring KW - Fatigue crack growth KW - Corrosion KW - Finite elements KW - Welds PY - 2012 SN - 1943-3514 VL - 5 IS - 1 SP - 9 EP - 17 PB - Global Scientech CY - Basking Ridge, NJ, USA AN - OPUS4-27610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Busch, C. A1 - Schröter, T. A1 - Grabolle, Markus A1 - Wenzel, M. A1 - Kempe, H. A1 - Kaiser, W.A. A1 - Resch-Genger, Ute A1 - Hilger, I. T1 - An in vivo spectral multiplexing approach for the cooperative imaging of different disease-related biomarkers with near-infrared fluorescent Förster resonance energy transfer probes N2 - In recent years, much progress has been made in analyzing the molecular origin of many diseases in vivo. For most applications, attention has been devoted to the detection of single molecules only. In this study, we present a proof of concept for the straightforward monitoring of interactions between different molecules via Förster resonance energy transfer (FRET) in an in vivo spectral multiplexing approach using conventional small organic dyes covalently attached to antibodies. Methods: We coupled the fluorophores DY-682 (donor; absorption [abs]/emission [em], 674/712 nm), DY-505 (control donor; abs/em, 498/529 nm), and DY-782 (acceptor; abs/em, 752/795 nm) to the model antibody IgG. The occurrence of FRET between these fluorophores was assessed in vitro for conjugate mixtures adsorbed onto membranes, after accumulation into the phagocytic compartment of macrophages (J774 cells), and in vivo in a mouse edema model using a whole-body animal imaging system with multispectral analysis features. Results: When the free acceptor DY-782 was combined with the DY-682 donor, FRET occurred as a consequence of small dye-to-dye distances, unlike the case for mixtures of the dyes DY-782 and DY-505. Our proof of concept was also transferred to living cells after internalization of the DY-682-IgG–DY-782-IgG pair into macrophages and finally to animals, where intermolecular FRET was observed after systemic probe application in vivo in edema-bearing mice. Conclusion: Our simple cooperative-imaging approach enables the noninvasive detection of the presence of two or principally even more neighboring disease-related biomarkers. This finding is of high relevance for the in vivo identification of complex biologic processes requiring strong spatial interrelations of target molecules in key pathologic activation processes such as inflammation, cancer, and neurodegenerative diseases. KW - FRET KW - IgG antibodies KW - In vivo molecular imaging KW - Near-infrared (NIR) fluorophores KW - Multiplexing KW - Cooperative signaling PY - 2012 DO - https://doi.org/10.2967/jnumed.111.094391 SN - 0161-5505 SN - 0097-9058 SN - 0022-3123 SN - 1535-5667 VL - 53 IS - 4 SP - 638 EP - 646 PB - SNM CY - Reston, Va. AN - OPUS4-26069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grandke, Julia A1 - Resch-Genger, Ute A1 - Bremser, Wolfram A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Quality assurance in immunoassay performance-temperature effects N2 - Temperature is one factor that influences the performance of immunoassays. Most commonly all incubation steps of the immunoassay are performed at ambient temperature. To systematically study the influence of temperature deviations on assay parameters like signal variation coefficients, limit of detection and measurement range, direct competitive enzyme immunoassays for the determination of two anthropogenic markers, caffeine and carbamazepine, were run at different temperatures above and below room temperature during individual assay steps. The temperature during the competition step had the greatest impact on the assay sensitivity yielding changes in test midpoints by a factor of 10 to 15. For carbamazepine, the test midpoints varied from 36 ng L-1, 108 ng L-1 to 378 ng L-1 employing 4 °C, 21 °C, or 37 °C as incubation temperature, respectively. The edge effect can be minimized resulting in a good plate homogeneity with small variation coefficients, when the assay is performed at ambient temperature. KW - Immunoassay KW - Temperature effects PY - 2012 DO - https://doi.org/10.1039/c2ay05918e SN - 1759-9660 SN - 1759-9679 IS - 4 SP - 901 EP - 905 PB - RSC Publ. CY - Cambridge AN - OPUS4-25740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grabolle, Markus A1 - Brehm, Robert A1 - Pauli, Jutta A1 - Dees, F.M. A1 - Hilger, I. A1 - Resch-Genger, Ute T1 - Determination of the labeling density of fluorophore-biomolecule conjugates with absorption spectroscopy N2 - Dye–biomolecule conjugation is frequently accompanied by considerable spectral changes of the dye’s absorption spectrum that limit the use of the common photometrical method for the determination of labeling densities. Here, we describe an improvement of this method using the integral absorbance of the dye instead of its absorbance at the long wavelength maximum to determine the concentration of the biomolecule-coupled dye. This approach is illustrated for three different cyanine dyes conjugated to the antibody IgG. KW - Fluorescent dye KW - Aggregation KW - Dimerization KW - Fluorophore-labeled antibodies KW - Labeling density KW - Dye-to-protein ratio KW - Absorption PY - 2012 DO - https://doi.org/10.1021/bc2003428 SN - 1043-1802 SN - 1520-4812 VL - 23 IS - 2 SP - 287 EP - 292 CY - Washington, DC AN - OPUS4-25527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habib, Abdel Karim A1 - Lohrer, Christian T1 - Numerical simulation and validation of pyrotechnic smoke emissions N2 - This paper aims at evaluating the practicability of an alternative strategy for the classical assessment of possible hazards aligned with the use of theatrical pyrotechnics especially at indoor venues, where the emission of solid reaction products (aerosols) is an important factor for permission for the use of pyrotechnics at stage shows. A CFD model was used to calculate the respective aerosol liberation and dispersion in a specific indoor facility. The results from these numerical simulations were compared with respective aerosol number concentration measurements carried out before, during, and after the burnoff of theatrical pyrotechnic fountains in an examination room, representing a small stage or theatre. The simulation results reveal a fair agreement with the experimental results in general, with the trend to conservatively over-predict the aerosol concentrations at close range to the pyrotechnic article. The time dependent increase and decline of the aerosol concentrations due to the ventilation conditions as observed in the preceding experimental studies could be reproduced in the simulations. KW - Theatrical pyrotechnic articles KW - Aerosols KW - CFD PY - 2012 SN - 1082-3999 IS - 31 SP - 10 EP - 21 CY - Whitewater, Colo. AN - OPUS4-26824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fleige, E. A1 - Ziem, B. A1 - Grabolle, Markus A1 - Haag, R. A1 - Resch-Genger, Ute T1 - Aggregation phenomena of host and guest upon the loading of dendritic core-multishell nanoparticles with solvatochromic dyes N2 - We systematically assessed the loading behavior of core-multishell nanoparticles (CMS NPs) for the solvatochromic dyes Coumarin 153 and Nile Red and studied the influence of the guest and its concentration on CMS NP aggregation using steady state absorption and fluorescence spectroscopy and dynamic light scattering (DLS). These measurements revealed the strong fluorescence of dye-loaded CMS NPs and formation of nonemissive dye aggregates in the outer CMS layer at higher loading concentrations of Nile Red, whereas in the case of Coumarin 153, a new species with red-shifted absorption and blue-shifted emission appeared. Moreover, dye loading triggers an aggregation of CMS NPs which have a hydrodynamic radius of 8 nm, thereby leading to CMS aggregates with a radius of 100–120 nm. These results underline the need for systematic studies of the influence of the guest and its loading concentration on CMS NP size for cellular uptake and in vivo imaging studies and the rational design of CMS NPs with improved transport and targeting abilities. PY - 2012 DO - https://doi.org/10.1021/ma301977r SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 23 SP - 9452 EP - 9459 PB - American Chemical Society CY - Washington, DC AN - OPUS4-27592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -