TY - JOUR A1 - Dittel, Gözdem A1 - Çiçek, Irem Ecem A1 - Bredol, Michael A1 - Gries, Thomas T1 - Carbon Rovings as Strain Sensor in TRC Structures: Effect of Roving Cross-Sectional Shape and Coating Material on the Electrical Response under Bending Stress JF - Sensors N2 - This study investigated the ability of electrically conductive carbon rovings to detect cracks in textile-reinforced concrete (TRC) structures. The key innovation lies in the integration of carbon rovings into the reinforcing textile, which not only contributes to the mechanical properties of the concrete structure but also eliminates the need for an additional sensory system, such as strain gauges, to monitor the structural health. Carbon rovings are integrated into a grid-like textile reinforcement that differs in binding type and dispersion concentration of the styrene butadiene rubber (SBR) coating. Ninety final samples were subjected to a four-point bending test in which the electrical changes of the carbon rovings were measured simultaneously to capture the strain. The mechanical results show that the SBR50-coated TRC samples with circular and elliptical cross-sectional shape achieved, with 1.55 kN, the highest bending tensile strength, which is also captured with a value of 0.65 Ω by the electrical impedance monitoring. The elongation and fracture of the rovings have a significant effect on the impedance mainly due to electrical resistance change. A correlation was found between the impedance change, binding type and coating. This suggests that the elongation and fracture mechanisms are affected by the number of outer and inner filaments, as well as the coating. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-170823 VL - 23 SP - 4601 ER - TY - GEN T1 - 28. Anwendertreffen Röntgenfluoreszenz- und Funkenemissionsspektrometrie N2 - Programm und Abstracts des 28. Anwendertreffen Röntgenfluoreszenz- und Funkenemissionsspektrometrie KW - Anwendertreffen Röntgenfluoreszenz- und Funkenemissionsspektrometrie Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-157524 ER - TY - JOUR A1 - Breuckmann, Michael A1 - Wacker, Georg A1 - Hanning, Stephanie A1 - Otto, Matthias A1 - Kreyenschmidt, Martin T1 - Quantification of C, H, N and O in polymers using WDXRF scattering spectra and PLS regression depending on the spectral resolution JF - Journal of Analytical Atomic Spectrometry N2 - A new approach to determine the elements carbon, hydrogen, nitrogen and oxygen (CHNO) in polymers by wavelength-dispersive X-ray fluorescence analysis (WDXRF) in combination with partial least squares (PLS) regression was explored. The quantification of CHNO was achieved by using the Rayleigh and Compton scattering spectra of an Rh X-ray tube from 84 different polymers. Concealed differences of the corresponding scattering spectra could be utilized to quantify CHNO in a multivariate manner. It was shown that the developed model was capable of determining these commonly non-measurable matrix elements in polymers using WDXRF. Furthermore, the influence of spectral resolution, which is given by the collimator and the crystal, on the prediction of CHNO was explored in this study. It was found that minimal spectral resolution led to the most accurate CHNO predictions. Information about matrix composition could be used to improve so-called semi-quantitative XRF methods based on fundamental parameters (FP) for the analysis of plastics, soil or other samples with high organic content. KW - X-ray fluorescence KW - Plastics KW - Quantification of "dark matrix" elements KW - PLS regression Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-149252 SN - 1364-5544 ER - TY - JOUR A1 - Bredol, Michael A1 - Voigt, Dominik A1 - Gonabadi, Atoosa T1 - A general strategy for CuInS2 based quantum dots with adjustable surface chemistry JF - Optical Materials N2 - Different from negatively charged CuInS2 (CIS) based quantum dots (QDs), positively charged QDs are difficult to obtain in good optical quality, but are desirable for certain applications. We herein present a general synthesis strategy that allows for a universal surface modification of ternary CIS based QDs with thiol containing ligands. The idea behind the synthesis design is, to apply a ZnS shell first for passivating and protecting the core QDs, and then add a second ZnS shell for the functionalization via ligand exchange. Whereby easy ligand exchange with thiolated molecules is systematically set up, by using a weak bonding amine ligand for the second shell. Molecules with various terminal groups were used to functionalize the nanoparticles and stabilize them in different media making any surface charge and polarity accessible. Surface defect chemistry seemed to play an important role in our synthesis strategy, therefore to gain a deeper understanding how these defect sites can alter the electronic structure of core/shell nanoparticles theoretical calculations based on density functional theory were performed, whilst structural, colloidal and optical properties were characterized experimentally (by dynamic light scattering, x-ray diffraction, infrared spectroscopy, zeta potential, absorption- and (time resolved) photoluminescence measurements). Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-137346 VL - 115 SP - 110994 EP - 111005 ER - TY - BOOK T1 - Akademisches Jahrbuch. Bachelor-Studiengang Chemical Engineering, Diplom-Studiengang Chemieingenieurwesen, Master of Science Chemical Engineering, Master of Science Materialwissenschaften. 01.05.2003 - 25.04.2004 N2 - Dieses Heft soll dem Leser einen Überblick über die Diplomarbeiten des vergangenen Jahres geben. Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-645 PB - FH Münster ER - TY - BOOK T1 - Zusammenfassung Diplomarbeiten der Absolventen, Studiengang Chemieingenieurwesen, 04.05.2001 - 03.05.2002 N2 - Dieses Heft soll dem Leser einen Überblick über die Diplomarbeiten des letzten Jahres geben. Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-635 PB - FH Münster ER -