@article{HeinEubanksLingametal.2022, author = {Hein, Andreas M. and Eubanks, T. Marshall and Lingam, Manasvi and Hibberd, Adam and Fries, Dan and Schneider, Jean and Kervella, Pierre and Kennedy, Robert and Perakis, Nikolaos and Dachwald, Bernd}, title = {Interstellar now! Missions to explore nearby interstellar objects}, series = {Advances in Space Research}, volume = {69}, journal = {Advances in Space Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2021.06.052}, pages = {402 -- 414}, year = {2022}, abstract = {The recently discovered first hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.}, language = {en} } @inproceedings{UlmerBraunChengetal.2022, author = {Ulmer, Jessica and Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Usage of digital twins for gamification applications in manufacturing}, series = {Procedia CIRP}, volume = {107}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, doi = {10.1016/j.procir.2022.05.044}, pages = {675 -- 680}, year = {2022}, abstract = {Gamification applications are on the rise in the manufacturing sector to customize working scenarios, offer user-specific feedback, and provide personalized learning offerings. Commonly, different sensors are integrated into work environments to track workers' actions. Game elements are selected according to the work task and users' preferences. However, implementing gamified workplaces remains challenging as different data sources must be established, evaluated, and connected. Developers often require information from several areas of the companies to offer meaningful gamification strategies for their employees. Moreover, work environments and the associated support systems are usually not flexible enough to adapt to personal needs. Digital twins are one primary possibility to create a uniform data approach that can provide semantic information to gamification applications. Frequently, several digital twins have to interact with each other to provide information about the workplace, the manufacturing process, and the knowledge of the employees. This research aims to create an overview of existing digital twin approaches for digital support systems and presents a concept to use digital twins for gamified support and training systems. The concept is based upon the Reference Architecture Industry 4.0 (RAMI 4.0) and includes information about the whole life cycle of the assets. It is applied to an existing gamified training system and evaluated in the Industry 4.0 model factory by an example of a handle mounting.}, language = {en} } @inproceedings{DannenSchindelePruemmeretal.2022, author = {Dannen, Tammo and Schindele, Benedikt and Pr{\"u}mmer, Marcel and Arntz, Kristian and Bergs, Thomas}, title = {Methodology for the self-optimizing determination of additive manufacturing process eligibility and optimization potentials in toolmaking}, series = {Procedia CIRP}, volume = {107}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, doi = {10.1016/j.procir.2022.05.188}, pages = {1539 -- 1544}, year = {2022}, abstract = {Additive Manufacturing (AM) of metallic workpieces faces a continuously rising technological relevance and market size. Producing complex or highly strained unique workpieces is a significant field of application, making AM highly relevant for tool components. Its successful economic application requires systematic workpiece based decisions and optimizations. Considering geometric and technological requirements as well as the necessary post-processing makes deciding effortful and requires in-depth knowledge. As design is usually adjusted to established manufacturing, associated technological and strategic potentials are often neglected. To embed AM in a future proof industrial environment, software-based self-learning tools are necessary. Integrated into production planning, they enable companies to unlock the potentials of AM efficiently. This paper presents an appropriate methodology for the analysis of process-specific AM-eligibility and optimization potential, added up by concrete optimization proposals. For an integrated workpiece characterization, proven methods are enlarged by tooling-specific figures. The first stage of the approach specifies the model's initialization. A learning set of tooling components is described using the developed key figure system. Based on this, a set of applicable rules for workpiece-specific result determination is generated through clustering and expert evaluation. Within the following application stage, strategic orientation is quantified and workpieces of interest are described using the developed key figures. Subsequently, the retrieved information is used for automatically generating specific recommendations relying on the generated ruleset of stage one. Finally, actual experiences regarding the recommendations are gathered within stage three. Statistic learning transfers those to the generated ruleset leading to a continuously deepening knowledge base. This process enables a steady improvement in output quality.}, language = {en} } @inproceedings{WeissHeslenfeldSaeweetal.2022, author = {Weiss, Christian and Heslenfeld, Jonas and Saewe, Jasmin Kathrin and Bremen, Sebastian and H{\"a}fner, Constantin Leon}, title = {Investigation on the influence of powder humidity in Laser Powder Bed Fusion (LPBF)}, series = {Procedia CIRP}, volume = {111}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, doi = {10.1016/j.procir.2022.08.102}, pages = {115 -- 120}, year = {2022}, abstract = {In the Laser Powder Bed Fusion (LPBF) process, parts are built out of metal powder material by exposure of a laser beam. During handling operations of the powder material, several influencing factors can affect the properties of the powder material and therefore directly influence the processability during manufacturing. Contamination by moisture due to handling operations is one of the most critical aspects of powder quality. In order to investigate the influences of powder humidity on LPBF processing, four materials (AlSi10Mg, Ti6Al4V, 316L and IN718) are chosen for this study. The powder material is artificially humidified, subsequently characterized, manufactured into cubic samples in a miniaturized process chamber and analyzed for their relative density. The results indicate that the processability and reproducibility of parts made of AlSi10Mg and Ti6Al4V are susceptible to humidity, while IN718 and 316L are barely influenced.}, language = {en} } @article{MonakhovaDiehl2022, author = {Monakhova, Yulia and Diehl, Bernd W.K.}, title = {Nuclear magnetic resonance spectroscopy as an elegant tool for a complete quality control of crude heparin material}, series = {Journal of Pharmaceutical and Biomedical Analysis}, volume = {219}, journal = {Journal of Pharmaceutical and Biomedical Analysis}, number = {Article number: 114915}, publisher = {Elsevier}, address = {New York, NY}, issn = {0731-7085}, doi = {10.1016/j.jpba.2022.114915}, year = {2022}, abstract = {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).}, language = {en} } @article{PourshahidiEngelmannOffenhaeusseretal.2022, author = {Pourshahidi, Ali Mohammad and Engelmann, Ulrich M. and Offenh{\"a}usser, Andreas and Krause, Hans-Joachim}, title = {Resolving ambiguities in core size determination of magnetic nanoparticles from magnetic frequency mixing data}, series = {Journal of Magnetism and Magnetic Materials}, volume = {563}, journal = {Journal of Magnetism and Magnetic Materials}, number = {In progress, Art. No. 169969}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2022.169969}, year = {2022}, abstract = {Frequency mixing magnetic detection (FMMD) has been widely utilized as a measurement technique in magnetic immunoassays. It can also be used for the characterization and distinction (also known as "colourization") of different types of magnetic nanoparticles (MNPs) based on their core sizes. In a previous work, it was shown that the large particles contribute most of the FMMD signal. This leads to ambiguities in core size determination from fitting since the contribution of the small-sized particles is almost undetectable among the strong responses from the large ones. In this work, we report on how this ambiguity can be overcome by modelling the signal intensity using the Langevin model in thermodynamic equilibrium including a lognormal core size distribution fL(dc,d0,σ) fitted to experimentally measured FMMD data of immobilized MNPs. For each given median diameter d0, an ambiguous amount of best-fitting pairs of parameters distribution width σ and number of particles Np with R2 > 0.99 are extracted. By determining the samples' total iron mass, mFe, with inductively coupled plasma optical emission spectrometry (ICP-OES), we are then able to identify the one specific best-fitting pair (σ, Np) one uniquely. With this additional externally measured parameter, we resolved the ambiguity in core size distribution and determined the parameters (d0, σ, Np) directly from FMMD measurements, allowing precise MNPs sample characterization.}, language = {en} } @article{EngelmannPourshahidiShalabyetal.2022, author = {Engelmann, Ulrich M. and Pourshahidi, Mohammad Ali and Shalaby, Ahmed and Krause, Hans-Joachim}, title = {Probing particle size dependency of frequency mixing magnetic detection with dynamic relaxation simulation}, series = {Journal of Magnetism and Magnetic Materials}, volume = {563}, journal = {Journal of Magnetism and Magnetic Materials}, number = {In progress, Art. No. 169965}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2022.169965}, year = {2022}, abstract = {Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles' magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing.}, language = {en} } @article{HaegerBongaertsSiegert2022, author = {Haeger, Gerrit and Bongaerts, Johannes and Siegert, Petra}, title = {A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent}, series = {Analytical Biochemistry}, journal = {Analytical Biochemistry}, number = {624}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0309}, doi = {10.1016/j.ab.2022.114819}, pages = {Artikel 114819}, year = {2022}, abstract = {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.}, language = {en} } @article{KahmannRauschPluemeretal.2022, author = {Kahmann, Stephanie L. and Rausch, Valentin and Pl{\"u}mer, Jonathan and M{\"u}ller, Lars P. and Pieper, Martin and Wegmann, Kilian}, title = {The automized fracture edge detection and generation of three-dimensional fracture probability heat maps}, series = {Medical Engineering \& Physics}, volume = {2022}, journal = {Medical Engineering \& Physics}, number = {110}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1350-4533}, pages = {7 Seiten}, year = {2022}, abstract = {With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further.}, language = {en} } @article{SchwagerFleschSchwarzboezletal.2022, author = {Schwager, Christian and Flesch, Robert and Schwarzb{\"o}zl, Peter and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e}}, title = {Advanced two phase flow model for transient molten salt receiver system simulation}, series = {Solar Energy}, volume = {232}, journal = {Solar Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0038-092X (print)}, doi = {10.1016/j.solener.2021.12.065}, pages = {362 -- 375}, year = {2022}, abstract = {In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed.}, language = {en} } @article{TopcuMadabhushiStaat2022, author = {Top{\c{c}}u, Murat and Madabhushi, Gopal S.P. and Staat, Manfred}, title = {A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius}, series = {International Journal of Solids and Structures}, volume = {239-240}, journal = {International Journal of Solids and Structures}, number = {Art. No. 111464}, publisher = {Elsevier}, address = {New York, NY}, issn = {0020-7683}, doi = {10.1016/j.ijsolstr.2022.111464}, year = {2022}, abstract = {A generalized shear-lag theory for fibres with variable radius is developed to analyse elastic fibre/matrix stress transfer. The theory accounts for the reinforcement of biological composites, such as soft tissue and bone tissue, as well as for the reinforcement of technical composite materials, such as fibre-reinforced polymers (FRP). The original shear-lag theory proposed by Cox in 1952 is generalized for fibres with variable radius and with symmetric and asymmetric ends. Analytical solutions are derived for the distribution of axial and interfacial shear stress in cylindrical and elliptical fibres, as well as conical and paraboloidal fibres with asymmetric ends. Additionally, the distribution of axial and interfacial shear stress for conical and paraboloidal fibres with symmetric ends are numerically predicted. The results are compared with solutions from axisymmetric finite element models. A parameter study is performed, to investigate the suitability of alternative fibre geometries for use in FRP.}, language = {en} } @article{DefosseKleinschmidtSchmutzetal.2022, author = {Defosse, Jerome and Kleinschmidt, Joris and Schmutz, Axel and Loop, Torsten and Staat, Manfred and Gatzweiler, Karl-Heinz and Wappler, Frank and Schieren, Mark}, title = {Dental strain on maxillary incisors during tracheal intubation with double-lumen tubes and different laryngoscopy techniques - a blinded manikin study}, series = {Journal of Cardiothoracic and Vascular Anesthesia}, volume = {36}, journal = {Journal of Cardiothoracic and Vascular Anesthesia}, number = {8, Part B}, publisher = {Elsevier}, address = {New York, NY}, issn = {1053-0770}, doi = {10.1053/j.jvca.2022.02.017}, pages = {3021 -- 3027}, year = {2022}, language = {en} } @article{RuebbelkeVoegeleGrajewskietal.2022, author = {R{\"u}bbelke, Dirk and V{\"o}gele, Stefan and Grajewski, Matthias and Zobel, Luzy}, title = {Hydrogen-based steel production and global climate protection: An empirical analysis of the potential role of a European cross border adjustment mechanism}, series = {Journal of Cleaner Production}, volume = {380}, journal = {Journal of Cleaner Production}, number = {Part 2, Art. Nr.:135040}, publisher = {Elsevier}, issn = {0959-6526}, doi = {10.1016/j.jclepro.2022.135040}, year = {2022}, abstract = {The European Union's aim to become climate neutral by 2050 necessitates ambitious efforts to reduce carbon emissions. Large reductions can be attained particularly in energy intensive sectors like iron and steel. In order to prevent the relocation of such industries outside the EU in the course of tightening environmental regulations, the establishment of a climate club jointly with other large emitters and alternatively the unilateral implementation of an international cross-border carbon tax mechanism are proposed. This article focuses on the latter option choosing the steel sector as an example. In particular, we investigate the financial conditions under which a European cross border mechanism is capable to protect hydrogen-based steel production routes employed in Europe against more polluting competition from abroad. By using a floor price model, we assess the competitiveness of different steel production routes in selected countries. We evaluate the climate friendliness of steel production on the basis of specific GHG emissions. In addition, we utilize an input-output price model. It enables us to assess impacts of rising cost of steel production on commodities using steel as intermediates. Our results raise concerns that a cross-border tax mechanism will not suffice to bring about competitiveness of hydrogen-based steel production in Europe because the cost tends to remain higher than the cost of steel production in e.g. China. Steel is a classic example for a good used mainly as intermediate for other products. Therefore, a cross-border tax mechanism for steel will increase the price of products produced in the EU that require steel as an input. This can in turn adversely affect competitiveness of these sectors. Hence, the effects of higher steel costs on European exports should be borne in mind and could require the cross-border adjustment mechanism to also subsidize exports.}, language = {en} } @article{KotliarOrtnerConradietal.2022, author = {Kotliar, Konstantin and Ortner, Marion and Conradi, Anna and Hacker, Patricia and Hauser, Christine and G{\"u}nthner, Roman and Moser, Michaela and Muggenthaler, Claudia and Diehl-Schmid, Janine and Priller, Josef and Schmaderer, Christoph and Grimmer, Timo}, title = {Altered retinal cerebral vessel oscillation frequencies in Alzheimer's disease compatible with impaired amyloid clearance}, series = {Neurobiology of Aging}, volume = {120}, journal = {Neurobiology of Aging}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0197-4580}, doi = {10.1016/j.neurobiolaging.2022.08.012}, pages = {117 -- 127}, year = {2022}, abstract = {Retinal vessels are similar to cerebral vessels in their structure and function. Moderately low oscillation frequencies of around 0.1 Hz have been reported as the driving force for paravascular drainage in gray matter in mice and are known as the frequencies of lymphatic vessels in humans. We aimed to elucidate whether retinal vessel oscillations are altered in Alzheimer's disease (AD) at the stage of dementia or mild cognitive impairment (MCI). Seventeen patients with mild-to-moderate dementia due to AD (ADD); 23 patients with MCI due to AD, and 18 cognitively healthy controls (HC) were examined using Dynamic Retinal Vessel Analyzer. Oscillatory temporal changes of retinal vessel diameters were evaluated using mathematical signal analysis. Especially at moderately low frequencies around 0.1 Hz, arterial oscillations in ADD and MCI significantly prevailed over HC oscillations and correlated with disease severity. The pronounced retinal arterial vasomotion at moderately low frequencies in the ADD and MCI groups would be compatible with the view of a compensatory upregulation of paravascular drainage in AD and strengthen the amyloid clearance hypothesis.}, language = {en} } @article{Maurischat2022, author = {Maurischat, Andreas}, title = {Algebraic independence of the Carlitz period and its hyperderivatives}, series = {Journal of Number Theory}, volume = {240}, journal = {Journal of Number Theory}, publisher = {Elsevier}, address = {Orlando, Fla.}, issn = {0022-314X}, doi = {10.1016/j.jnt.2022.01.006}, pages = {145 -- 162}, year = {2022}, language = {en} } @article{MonakhovaDiehl2022, author = {Monakhova, Yulia and Diehl, Bernd W.K.}, title = {Multinuclear NMR screening of pharmaceuticals using standardization by 2H integral of a deuterated solvent}, series = {Journal of Pharmaceutical and Biomedical Analysis}, volume = {209}, journal = {Journal of Pharmaceutical and Biomedical Analysis}, number = {Article number: 114530}, publisher = {Elsevier}, isbn = {0731-7085}, doi = {10.1016/j.jpba.2021.114530}, year = {2022}, abstract = {NMR standardization approach that uses the 2H integral of deuterated solvent for quantitative multinuclear analysis of pharmaceuticals is described. As a proof of principle, the existing NMR procedure for the analysis of heparin products according to US Pharmacopeia monograph is extended to the determination of Na+ and Cl- content in this matrix. Quantification is performed based on the ratio of a 23Na (35Cl) NMR integral and 2H NMR signal of deuterated solvent, D2O, acquired using the specific spectrometer hardware. As an alternative, the possibility of 133Cs standardization using the addition of Cs2CO3 stock solution is shown. Validation characteristics (linearity, repeatability, sensitivity) are evaluated. A holistic NMR profiling of heparin products can now also be used for the quantitative determination of inorganic compounds in a single analytical run using a single sample. In general, the new standardization methodology provides an appealing alternative for the NMR screening of inorganic and organic components in pharmaceutical products.}, language = {en} } @article{BurgerLindnerRumpfetal.2022, author = {Burger, Ren{\´e} and Lindner, Simon and Rumpf, Jessica and Do, Xuan Tung and Diehl, Bernd W.K. and Rehahn, Matthias and Monakhova, Yulia and Schulze, Margit}, title = {Benchtop versus high field NMR: Comparable performance found for the molecular weight determination of lignin}, series = {Journal of Pharmaceutical and Biomedical Analysis}, volume = {212}, journal = {Journal of Pharmaceutical and Biomedical Analysis}, number = {Article number: 114649}, publisher = {Elsevier}, address = {New York, NY}, isbn = {0731-7085}, doi = {10.1016/j.jpba.2022.114649}, year = {2022}, abstract = {Lignin is a promising renewable biopolymer being investigated worldwide as an environmentally benign substitute of fossil-based aromatic compounds, e.g. for the use as an excipient with antioxidant and antimicrobial properties in drug delivery or even as active compound. For its successful implementation into process streams, a quick, easy, and reliable method is needed for its molecular weight determination. Here we present a method using 1H spectra of benchtop as well as conventional NMR systems in combination with multivariate data analysis, to determine lignin's molecular weight (Mw and Mn) and polydispersity index (PDI). A set of 36 organosolv lignin samples (from Miscanthus x giganteus, Paulownia tomentosa and Silphium perfoliatum) was used for the calibration and cross validation, and 17 samples were used as external validation set. Validation errors between 5.6\% and 12.9\% were achieved for all parameters on all NMR devices (43, 60, 500 and 600 MHz). Surprisingly, no significant difference in the performance of the benchtop and high-field devices was found. This facilitates the application of this method for determining lignin's molecular weight in an industrial environment because of the low maintenance expenditure, small footprint, ruggedness, and low cost of permanent magnet benchtop NMR systems.}, language = {en} } @article{MonakhovaSobolevaFedotovaetal.2022, author = {Monakhova, Yulia and Soboleva, Polina M. and Fedotova, Elena S. and Musina, Kristina T. and Burmistrova, Natalia A.}, title = {Quantum chemical calculations of IR spectra of heparin disaccharide subunits}, series = {Computational and Theoretical Chemistry}, volume = {1217}, journal = {Computational and Theoretical Chemistry}, number = {Article number: 113891}, publisher = {Elsevier}, address = {New York, NY}, isbn = {2210-271X}, doi = {10.1016/j.comptc.2022.113891}, year = {2022}, abstract = {Heparin is a natural polysaccharide, which plays essential role in many biological processes. Alterations in building blocks can modify biological roles of commercial heparin products, due to significant changes in the conformation of the polymer chain. The variability structure of heparin leads to difficulty in quality control using different analytical methods, including infrared (IR) spectroscopy. In this paper molecular modelling of heparin disaccharide subunits was performed using quantum chemistry. The structural and spectral parameters of these disaccharides have been calculated using RHF/6-311G. In addition, over-sulphated chondroitin sulphate disaccharide was studied as one of the most widespread contaminants of heparin. Calculated IR spectra were analyzed with respect to specific structure parameters. IR spectroscopic fingerprint was found to be sensitive to substitution pattern of disaccharide subunits. Vibrational assignments of calculated spectra were correlated with experimental IR spectral bands of native heparin. Chemometrics was used to perform multivariate analysis of simulated spectral data.}, language = {en} } @incollection{AkimbekovDigelRazzaque2022, author = {Akimbekov, Nuraly S. and Digel, Ilya and Razzaque, Mohammed S.}, title = {Role of vitamins in maintaining structure and function of intestinal microbiome}, series = {Comprehensive Gut Microbiota}, booktitle = {Comprehensive Gut Microbiota}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-822036-8}, doi = {10.1016/B978-0-12-819265-8.00043-7}, pages = {320 -- 334}, year = {2022}, abstract = {The recent advances in microbiology have shed light on understanding the role of vitamins beyond the nutritional range. Vitamins are critical in contributing to healthy biodiversity and maintaining the proper function of gut microbiota. The sharing of vitamins among bacterial populations promotes stability in community composition and diversity; however, this balance becomes disturbed in various pathologies. Here, we overview and analyze the ability of different vitamins to selectively and specifically induce changes in the intestinal microbial community. Some schemes and regularities become visible, which may provide new insights and avenues for therapeutic management and functional optimization of the gut microbiota.}, language = {en} } @article{ValeroBungErpicumetal.2022, author = {Valero, Daniel and Bung, Daniel B. and Erpicum, Sebastien and Peltier, Yann and Dewals, Benjamin}, title = {Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling}, series = {Journal of Hydro-environment Research}, journal = {Journal of Hydro-environment Research}, number = {In Press}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2022.03.002}, year = {2022}, abstract = {Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).}, language = {en} }