TY - JOUR A1 - Schwab, Lukas A1 - Hojdis, Nils A1 - Lacayo, Jorge A1 - Wilhelm, Manfred T1 - Fourier-Transform Rheology of Unvulcanized, Carbon Black Filled Styrene Butadiene Rubber JF - Macromolecular Materials and Engineering N2 - Rubber materials filled with reinforcing fillers display nonlinear rheological behavior at small strain amplitudes below γ0 < 0.1. Nevertheless, rheological data are analyzed mostly in terms of linear parameters, such as shear moduli (G′, G″), which loose their physical meaning in the nonlinear regime. In this work styrene butadiene rubber filled with carbon black (CB) under large amplitude oscillatory shear (LAOS) is analyzed in terms of the nonlinear parameter I3/1. Three different CB grades are used and the filler load is varied between 0 and 70 phr. It is found that I3/1(φ) is most sensitive to changes of the total accessible filler surface area at low strain amplitudes (γ0 = 0.32). The addition of up to 70 phr CB leads to an increase of I3/1(φ) by a factor of more than ten. The influence of the measurement temperature on I3/1 is pronounced for CB levels above the percolation threshold. Y1 - 2016 U6 - http://dx.doi.org/10.1002/mame.201500356 SN - 1439-2054 VL - 301 IS - 4 SP - 457 EP - 468 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Harish, Ajay B. A1 - Wriggers, Peter A1 - Jungk, Juliane A1 - Hojdis, Nils A1 - Recker, Carla T1 - Mesoscale Constitutive Modeling of Non-Crystallizing Filled Elastomers JF - Computational Mechanics N2 - Elastomers are exceptional materials owing to their ability to undergo large deformations before failure. However, due to their very low stiffness, they are not always suitable for industrial applications. Addition of filler particles provides reinforcing effects and thus enhances the material properties that render them more versatile for applications like tyres etc. However, deformation behavior of filled polymers is accompanied by several nonlinear effects like Mullins and Payne effect. To this day, the physical and chemical changes resulting in such nonlinear effect remain an active area of research. In this work, we develop a heterogeneous (or multiphase) constitutive model at the mesoscale explicitly considering filler particle aggregates, elastomeric matrix and their mechanical interaction through an approximate interface layer. The developed constitutive model is used to demonstrate cluster breakage, also, as one of the possible sources for Mullins effect observed in non-crystallizing filled elastomers. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00466-015-1251-1 SN - 1432-0924 VL - 57 SP - 653 EP - 677 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hentschke, Reinhard A1 - Hager, Jonathan A1 - Hojdis, Nils T1 - Molecular Modeling Approach to the Prediction of Mechanical Properties of Silica-Reinforced Rubbers JF - Journal of Applied Polymer Science N2 - Recently, we have suggested a nanomechanical model for dissipative loss in filled elastomer networks in the context of the Payne effect. The mechanism is based on a total interfiller particle force exhibiting an intermittent loop, due to the combination of short-range repulsion and dispersion forces with a long-range elastic attraction. The sum of these forces leads, under external strain, to a spontaneous instability of “bonds” between the aggregates in a filler network and attendant energy dissipation. Here, we use molecular dynamics simulations to obtain chemically realistic forces between surface modified silica particles. The latter are combined with the above model to estimate the loss modulus and the low strain storage modulus in elastomers containing the aforementioned filler-compatibilizer systems. The model is compared to experimental dynamic moduli of silica filled rubbers. We find good agreement between the model predictions and the experiments as function of the compatibilizer's molecular structure and its bulk concentration. KW - theory and modeling KW - supramolecular structures KW - rubber KW - mechanical properties KW - elastomers Y1 - 2014 U6 - http://dx.doi.org/10.1002/app.40806 SN - 1097-4628 VL - 131 IS - 18 SP - 1 EP - 9 PB - Wiley CY - New York, NY ER - TY - PAT A1 - Finger, Sebastian A1 - Hojdis, Nils A1 - Menglong, Huang T1 - Sekundäre galvanische Zelle N2 - Die vorliegende Erfindung betrifft eine sekundäre galvanische Zelle, umfassend eine Kathode, eine Anode und einen Separator, der zwischen der Kathode und der Anode angeordnet ist, wobei die Kathode ein erstes elastomeres Polymer umfasst, welches mit einem ersten Füllstoff als Kathodenmaterial gefüllt ist, wobei die Anode ein zweites elastomeres Polymer umfasst, welches mit einem zweiten Füllstoff als Anodenmaterial gefüllt ist, wobei der Separator ein drittes elastomeres Polymer umfasst, wobei das erste elastomere Polymer, das zweite elastomere Polymer und das dritte elastomere Polymer unabhängig voneinander aus vernetzungsfähigen Dienkautschuken ausgewählt sind, und wobei zumindest eines von dem ersten elastomeren Polymer, dem zweiten elastomeren Polymer und dem dritten elastomeren Polymer eine ionische Flüssigkeit und/oder ein elektrisch leitfähiges Polymer enthält. Die vorliegende Erfindung betrifft ferner eine wiederaufladbare Batterie, umfassend die erfindungsgemäße sekundäre galvanische Zelle, ein Verfahren zur Herstellung einer sekundären galvanischen Zelle sowie die Verwendung der erfindungsgemäßen sekundären galvanischen Zelle sowie der erfindungsgemäßen wiederaufladbaren Batterie. Y1 - 2020 N1 - Patent DE102018222385A1 25.06.2020 auch veröffentlicht unter EP3671932A1 ER - TY - PAT A1 - Hojdis, Nils A1 - Recker, Carla T1 - Schwefelvernetzte Kautschukmischung für Fahrzeugreifen enthaltend Carbon Nanotubes (cnt), Fahrzeugreifen, Der Die schwefelvernetzte Kautschukmischung aufweist, sowie Verfahren zur Herstellung der schwefelvernetzten Kautschukmischung enthaltend Cnt Y1 - 2020 N1 - Patent EP000003625288A1 25.03.2020 auch veröffentlicht unter CN110678508A; DE102017208137A1; WO2018210471A1 ER - TY - PAT A1 - Ehmke, Tobias A1 - Finger, Sebastian A1 - Hojdis, Nils A1 - Kurz, Martin A1 - Nawrocka-Herczynska, Monika T1 - Funkeinheit und Vorrichtung mit einer Funkeinheit N2 - Dargestellt und beansprucht ist eine Funkeinheit mit einem Funkbauteil, einer elektrisch leitfähigen Antenne und einem Kunststoffverbindungsmittel. Das Funkbauteil weist einen Antennenanschluss auf. Das Kunststoffverbindungsmittel weist ein erstes Elastomermaterial mit elektrisch leitfähigem Zusatzmaterial auf, so dass das Kunststoffverbindungsmittel elektrisch leitfähig ist. Das Kunststoffverbindungsmittel bildet eine mechanische und elektrisch leitfähige Verbindung zwischen dem Antennenanschluss und der Antenne. Weiterhin wird eine Vorrichtung mit einem ein Matrixmaterial mit oder aus einem zweiten Elastomermaterial und einer Funkeinheit beschrieben und beansprucht, wobei die Funkeinheit vollständig in das Matrixmaterial eingebettet ist. Die Vorrichtung kann insbesondere ein Fahrzeugreifen sein. Y1 - 2020 N1 - Patent DE102018222380A1 25.06.2020 ER - TY - PAT A1 - Hojdis, Nils T1 - Verfahren zum Bestimmen einer Sitzeinstellung eines Sitzes eines Kraftfahrzeugs, Computerprogrammprodukt, Servereinrichtung, Kommunikationsendgerät und Kraftfahrzeug N2 - Die Erfindung betrifft ein Verfahren zum Bestimmen einer Sitzeinstellung (23) eines Sitzes (3) eines Kraftfahrzeugs (1), bei welchem folgende Schritte durchgeführt werden:- Bereitstellen einer Körperabmessung (12) eines Nutzers (6) des Kraftfahrzeugs (1);- Bereitstellen einer Sitzeigenschaft (13) des Sitzes (3) des Kraftfahrzeugs (1);- Bereitstellen eines mit zumindest einer Referenzsitzeigenschaft (20), zumindest einer Referenzkörperabmessung (21) und zumindest einer Referenzsitzeinstellung (22) trainiertes künstliches neuronales Netz (14); und- Bestimmen der Sitzeinstellung (23) durch Eingabe der Körperabmessung (12) und der Sitzeigenschaft (13) in das künstliche neuronale Netz (14). Y1 - 2019 N1 - Patent DE102018211831A1 05.12.2019 ER - TY - PAT A1 - Dauer, David-Raphael A1 - Hojdis, Nils A1 - Müller, Norbert A1 - Recker, Carla A1 - Schax, Fabian A1 - Schöffel, Julia A1 - Tarantola, Gesa A1 - Weber, Christine T1 - Schwefelvernetzbare Kautschukmischung, Vulkanisat der Kautschukmischung und Fahrzeugreifen N2 - Die Erfindung betrifft eine schwefelvernetzbare Kautschukmischung, deren Vulkanisat und einen Fahrzeugreifen.Die schwefelvernetzbare Kautschukmischung enthält wenigstens die folgenden Bestandteile:- wenigstens einen Dienkautschuk; und- 10 bis 300 phr wenigstens einer Kieselsäure ; und- 1 bis 30 phf wenigstens eines Silans A mit der allgemeinen Summenformel A-I)und- 0,5 bis 30 phf wenigstens eines Silans B mit der allgemeinen Summenformel B-I)wobei u gleich 0, 1, 2 oder 3 und v gleich 0 oder 1 ist. Y1 - 2019 N1 - Patent DE102017221236A1 29.05.2019 auch veröffentlicht unter CN111405987A; TW201925305A; WO2019105615A1 ER - TY - JOUR A1 - Everaers, Ralf A1 - Karimi-Varzaneh, Hossein Ali A1 - Fleck, Franz A1 - Hojdis, Nils A1 - Svaneborg, Carsten T1 - Kremer–Grest Models for Commodity Polymer Melts: Linking Theory, Experiment, and Simulation at the Kuhn Scale JF - Macromolecules N2 - The Kremer–Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers. Y1 - 2020 U6 - http://dx.doi.org/10.1021/acs.macromol.9b02428 SN - 1520-5835 VL - 53 IS - 6 SP - 1901 EP - 1916 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Meyer, Jan A1 - Hentschke, Reinhard A1 - Hager, Jonathan A1 - Hojdis, Nils A1 - Karimi-Varzaneh, Hossein Ali T1 - Molecular Simulation of Viscous Dissipation due to Cyclic Deformation of a Silica–Silica Contact in Filled Rubber JF - Macromolecules Y1 - 2017 U6 - http://dx.doi.org/10.1021/acs.macromol.7b00947 SN - 1520-5835 VL - 50 IS - 17 SP - 6679 EP - 6689 ER - TY - JOUR A1 - Hager, Jonathan A1 - Hentschke, Reinhard A1 - Hojdis, Nils A1 - Karimi-Varzaneh, Hossein Ali T1 - Computer Simulation of Particle–Particle Interaction in a Model Polymer Nanocomposite JF - Macromolecules Y1 - 2015 U6 - http://dx.doi.org/10.1021/acs.macromol.5b01864 SN - 1520-5835 VL - 48 IS - 24 SP - 9039 EP - 9049 ER - TY - JOUR A1 - Waller, Mark P. A1 - Braun, Heiko A1 - Hojdis, Nils A1 - Bühl, Michael T1 - Geometries of Second-Row Transition-Metal Complexes from Density-Functional Theory JF - Journal of Chemical Theory and Computation Y1 - 2007 U6 - http://dx.doi.org/10.1021/ct700178y SN - 1549-9626 VL - 3 IS - 6 SP - 2234 EP - 2242 ER - TY - JOUR A1 - Svaneborg, Carsten A1 - Karimi-Varzaneh, Hossein Ali A1 - Hojdis, Nils A1 - Fleck, Franz A1 - Everaers, Ralf T1 - Kremer-Grest Models for Universal Properties of Specific Common Polymer Species JF - Soft Condensed Matter N2 - The Kremer-Grest (KG) bead-spring model is a near standard in Molecular Dynamic simulations of generic polymer properties. It owes its popularity to its computational efficiency, rather than its ability to represent specific polymer species and conditions. Here we investigate how to adapt the model to match the universal properties of a wide range of chemical polymers species. For this purpose we vary a single parameter originally introduced by Faller and Müller-Plathe, the chain stiffness. Examples include polystyrene, polyethylene, polypropylene, cis-polyisoprene, polydimethylsiloxane, polyethyleneoxide and styrene-butadiene rubber. We do this by matching the number of Kuhn segments per chain and the number of Kuhn segments per cubic Kuhn volume for the polymer species and for the Kremer-Grest model. We also derive mapping relations for converting KG model units back to physical units, in particular we obtain the entanglement time for the KG model as function of stiffness allowing for a time mapping. To test these relations, we generate large equilibrated well entangled polymer melts, and measure the entanglement moduli using a static primitive-path analysis of the entangled melt structure as well as by simulations of step-strain deformation of the model melts. The obtained moduli for our model polymer melts are in good agreement with the experimentally expected moduli. Y1 - 2018 IS - 1606.05008 ER - TY - BOOK A1 - Lauth, Jakob T1 - Physikalische Chemie kompakt KW - Physikalische Chemie Y1 - 2022 SN - 978-3-662-64587-1 U6 - http://dx.doi.org/https://doi.org/10.1007/978-3-662-64588-8 PB - Springer Spektrum CY - Berlin ER - TY - JOUR A1 - Monakhova, Yulia A1 - Diehl, Bernd W.K. T1 - Nuclear magnetic resonance spectroscopy as an elegant tool for a complete quality control of crude heparin material JF - Journal of Pharmaceutical and Biomedical Analysis N2 - Nuclear magnetic resonance (NMR) spectrometric methods for the quantitative analysis of pure heparin in crude heparin is proposed. For quantification, a two-step routine was developed using a USP heparin reference sample for calibration and benzoic acid as an internal standard. The method was successfully validated for its accuracy, reproducibility, and precision. The methodology was used to analyze 20 authentic porcine heparinoid samples having heparin content between 4.25 w/w % and 64.4 w/w %. The characterization of crude heparin products was further extended to a simultaneous analysis of these common ions: sodium, calcium, acetate and chloride. A significant, linear dependence was found between anticoagulant activity and assayed heparin content for thirteen heparinoids samples, for which reference data were available. A Diffused-ordered NMR experiment (DOSY) can be used for qualitative analysis of specific glycosaminoglycans (GAGs) in heparinoid matrices and, potentially, for quantitative prediction of molecular weight of GAGs. NMR spectrometry therefore represents a unique analytical method suitable for the simultaneous quantitative control of organic and inorganic composition of crude heparin samples (especially heparin content) as well as an estimation of other physical and quality parameters (molecular weight, animal origin and activity). KW - NMR spectroscopy KW - Heparin KW - Crude heparin KW - USP KW - Ions Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.jpba.2022.114915 SN - 0731-7085 VL - 219 IS - Article number: 114915 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Falkenberg, Fabian A1 - Bott, Michael A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - Phylogenetic survey of the subtilase family and a data-mining-based search for new subtilisins from Bacillaceae JF - Frontiers in Microbiology N2 - The subtilase family (S8), a member of the clan SB of serine proteases are ubiquitous in all kingdoms of life and fulfil different physiological functions. Subtilases are divided in several groups and especially subtilisins are of interest as they are used in various industrial sectors. Therefore, we searched for new subtilisin sequences of the family Bacillaceae using a data mining approach. The obtained 1,400 sequences were phylogenetically classified in the context of the subtilase family. This required an updated comprehensive overview of the different groups within this family. To fill this gap, we conducted a phylogenetic survey of the S8 family with characterised holotypes derived from the MEROPS database. The analysis revealed the presence of eight previously uncharacterised groups and 13 subgroups within the S8 family. The sequences that emerged from the data mining with the set filter parameters were mainly assigned to the subtilisin subgroups of true subtilisins, high-alkaline subtilisins, and phylogenetically intermediate subtilisins and represent an excellent source for new subtilisin candidates. Y1 - 2022 U6 - http://dx.doi.org/10.3389/fmicb.2022.1017978 SN - 1664-302X VL - 2022 IS - 13 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Haeger, Gerrit A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent JF - Analytical Biochemistry N2 - An improved and convenient ninhydrin assay for aminoacylase activity measurements was developed using the commercial EZ Nin™ reagent. Alternative reagents from literature were also evaluated and compared. The addition of DMSO to the reagent enhanced the solubility of Ruhemann's purple (RP). Furthermore, we found that the use of a basic, aqueous buffer enhances stability of RP. An acidic protocol for the quantification of lysine was developed by addition of glacial acetic acid. The assay allows for parallel processing in a 96-well format with measurements microtiter plates. Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.ab.2022.114819 SN - 1096-0309 IS - 624 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Welden, Melanie A1 - Severins, Robin A1 - Poghossian, Arshak A1 - Wege, Christina A1 - Bongaerts, Johannes A1 - Siegert, Petra A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor JF - Chemosensors N2 - Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte–insulator–semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716ᵀ is immobilized via biotin–streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage–current, capacitance–voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution. Y1 - 2022 U6 - http://dx.doi.org/10.3390/chemosensors10060218 SN - 2227-9040 N1 - This article belongs to the Special Issue "Nanostructured Devices for Biochemical Sensing" VL - 10 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ojovan, Michael I. A1 - Steinmetz, Hans-Jürgen T1 - Approaches to Disposal of Nuclear Waste JF - Energies N2 - We present a concise mini overview on the approaches to the disposal of nuclear waste currently used or deployed. The disposal of nuclear waste is the end point of nuclear waste management (NWM) activities and is the emplacement of waste in an appropriate facility without the intention to retrieve it. The IAEA has developed an internationally accepted classification scheme based on the end points of NWM, which is used as guidance. Retention times needed for safe isolation of waste radionuclides are estimated based on the radiotoxicity of nuclear waste. Disposal facilities usually rely on a multi-barrier defence system to isolate the waste from the biosphere, which comprises the natural geological barrier and the engineered barrier system. Disposal facilities could be of a trench type, vaults, tunnels, shafts, boreholes, or mined repositories. A graded approach relates the depth of the disposal facilities’ location with the level of hazard. Disposal practices demonstrate the reliability of nuclear waste disposal with minimal expected impacts on the environment and humans. KW - borehole disposal KW - geological disposal KW - disposal facility KW - retention time KW - nuclear waste Y1 - 2022 U6 - http://dx.doi.org/10.3390/en15207804 SN - 1996-1073 N1 - This article belongs to the Special Issue "Treatment of Radioactive Waste and Sustainability Energy" VL - 15 IS - 20 PB - MDPI CY - Basel ER - TY - JOUR A1 - Zhantlessova, Sirina A1 - Savitskaya, Irina A1 - Kistaubayeva, Aida A1 - Ignatova, Ludmila A1 - Talipova, Aizhan A1 - Pogrebnjak, Alexander A1 - Digel, Ilya T1 - Advanced “Green” prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy JF - Polymers N2 - Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for “grafting” of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality. KW - coculture KW - pullulan KW - exopolysaccharides KW - prebiotic KW - bacterial cellulose Y1 - 2022 U6 - http://dx.doi.org/10.3390/polym14153224 SN - 2073-4360 N1 - This article belongs to the Special Issue "Cellulose Based Composites" VL - 14 IS - 15 PB - MDPI CY - Basel ER -