@article{ReisgenSchleserAbdurakhmanovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Gumenyuk, Andrey}, title = {Measuring of plasma properties induced by non-vacuum electron beam welding}, series = {Physics of plasma}, volume = {19}, journal = {Physics of plasma}, number = {1}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {1089-7674 (E-Journal); 1070-664X (Print)}, doi = {10.1063/1.3675874}, year = {2012}, abstract = {Electron beam plasma measurement was realised by means of DIABEAM system invented by ISF RWTH Aachen. The Langmuir probe method is used for measurement. The relative simplicity of the method and the possibility of dispersion of high power on the probe allow its application for the investigation of high-power electron beams. The key element of the method is a rotating thin tungsten wire, which intersects the beam transversely on its axis and collects part of the current by itself. The signals, which are registered in the DIABEAM as a voltage, were taken in the form of amplitude. The conversion of the probe current into the distribution along the beam radius was realised using the Abel's method. A voltage-current characteristic was built for the beam current. The local electron density as well as the electron temperature, the floating potential and the plasma potential were measured and calculated by means of this characteristic.}, language = {en} } @article{ReisgenOlschokJakobsetal.2012, author = {Reisgen, Uwe and Olschok, Simon and Jakobs, Stefan and Schleser, Markus and Mokrov, Oleg and Rossiter, Eduardo}, title = {Laser beam submerged arc hybrid welding}, series = {Physics procedia}, volume = {39}, journal = {Physics procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.10.016}, pages = {75 -- 83}, year = {2012}, abstract = {The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.}, language = {en} } @article{BernauKnoedlerEmontsetal.2022, author = {Bernau, C. R. and Kn{\"o}dler, Matthias and Emonts, Jessica and J{\"a}pel, Ronald Colin and Buyel, Johannes Felix}, title = {The use of predictive models to develop chromatography-based purification processes}, series = {Frontiers in Bioengineering and Biotechnology}, journal = {Frontiers in Bioengineering and Biotechnology}, number = {10}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-4185 (online-ressource)}, doi = {10.3389/fbioe.2022.1009102}, pages = {25 Seiten}, year = {2022}, abstract = {Chromatography is the workhorse of biopharmaceutical downstream processing because it can selectively enrich a target product while removing impurities from complex feed streams. This is achieved by exploiting differences in molecular properties, such as size, charge and hydrophobicity (alone or in different combinations). Accordingly, many parameters must be tested during process development in order to maximize product purity and recovery, including resin and ligand types, conductivity, pH, gradient profiles, and the sequence of separation operations. The number of possible experimental conditions quickly becomes unmanageable. Although the range of suitable conditions can be narrowed based on experience, the time and cost of the work remain high even when using high-throughput laboratory automation. In contrast, chromatography modeling using inexpensive, parallelized computer hardware can provide expert knowledge, predicting conditions that achieve high purity and efficient recovery. The prediction of suitable conditions in silico reduces the number of empirical tests required and provides in-depth process understanding, which is recommended by regulatory authorities. In this article, we discuss the benefits and specific challenges of chromatography modeling. We describe the experimental characterization of chromatography devices and settings prior to modeling, such as the determination of column porosity. We also consider the challenges that must be overcome when models are set up and calibrated, including the cross-validation and verification of data-driven and hybrid (combined data-driven and mechanistic) models. This review will therefore support researchers intending to establish a chromatography modeling workflow in their laboratory.}, language = {en} } @article{EmontsBuyel2023, author = {Emonts, Jessica and Buyel, Johannes Felix}, title = {An overview of descriptors to capture protein properties - Tools and perspectives in the context of QSAR modeling}, series = {Computational and Structural Biotechnology Journal}, journal = {Computational and Structural Biotechnology Journal}, number = {21}, publisher = {Research Network of Computational and Structural Biotechnology}, address = {Gotenburg}, issn = {2001-0370 (online-ressource)}, doi = {10.1016/j.csbj.2023.05.022}, pages = {3234 -- 3247}, year = {2023}, abstract = {Proteins are important ingredients in food and feed, they are the active components of many pharmaceutical products, and they are necessary, in the form of enzymes, for the success of many technical processes. However, production can be challenging, especially when using heterologous host cells such as bacteria to express and assemble recombinant mammalian proteins. The manufacturability of proteins can be hindered by low solubility, a tendency to aggregate, or inefficient purification. Tools such as in silico protein engineering and models that predict separation criteria can overcome these issues but usually require the complex shape and surface properties of proteins to be represented by a small number of quantitative numeric values known as descriptors, as similarly used to capture the features of small molecules. Here, we review the current status of protein descriptors, especially for application in quantitative structure activity relationship (QSAR) models. First, we describe the complexity of proteins and the properties that descriptors must accommodate. Then we introduce descriptors of shape and surface properties that quantify the global and local features of proteins. Finally, we highlight the current limitations of protein descriptors and propose strategies for the derivation of novel protein descriptors that are more informative.}, language = {en} } @phdthesis{Emonts2013, author = {Emonts, Jessica}, title = {Searching for many defective edges in hypergraphs}, publisher = {Rheinisch-Westf{\"a}lischen Technischen Hochschule Aachen}, address = {Aachen}, pages = {VIII, 104 Seiten : Ill.}, year = {2013}, language = {en} } @article{KnoedlerRuehlEmontsetal.2019, author = {Kn{\"o}dler, Matthias and R{\"u}hl, Clemens and Emonts, Jessica and Buyel, Johannes Felix}, title = {Seasonal weather changes affect the yield and quality of recombinant proteins produced in transgenic tobacco plants in a greenhouse setting}, series = {Frontiers in Plant Science}, journal = {Frontiers in Plant Science}, number = {10}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-462X (online-ressource)}, doi = {10.3389/fpls.2019.01245}, pages = {13 Seiten}, year = {2019}, abstract = {Transgenic plants have the potential to produce recombinant proteins on an agricultural scale, with yields of several tons per year. The cost-effectiveness of transgenic plants increases if simple cultivation facilities such as greenhouses can be used for production. In such a setting, we expressed a novel affinity ligand based on the fluorescent protein DsRed, which we used as a carrier for the linear epitope ELDKWA from the HIV-neutralizing antibody 2F5. The DsRed-2F5-epitope (DFE) fusion protein was produced in 12 consecutive batches of transgenic tobacco (Nicotiana tabacum) plants over the course of 2 years and was purified using a combination of blanching and immobilized metal-ion affinity chromatography (IMAC). The average purity after IMAC was 57 ± 26\% (n = 24) in terms of total soluble protein, but the average yield of pure DFE (12 mg kg-1) showed substantial variation (± 97 mg kg-1, n = 24) which correlated with seasonal changes. Specifically, we found that temperature peaks (>28°C) and intense illuminance (>45 klx h-1) were associated with lower DFE yields after purification, reflecting the loss of the epitope-containing C-terminus in up to 90\% of the product. Whereas the weather factors were of limited use to predict product yields of individual harvests conducted for each batch (spaced by 1 week), the average batch yields were well approximated by simple linear regression models using two independent variables for prediction (illuminance and plant age). Interestingly, accumulation levels determined by fluorescence analysis were not affected by weather conditions but positively correlated with plant age, suggesting that the product was still expressed at high levels, but the extreme conditions affected its stability, albeit still preserving the fluorophore function. The efficient production of intact recombinant proteins in plants may therefore require adequate climate control and shading in greenhouses or even cultivation in fully controlled indoor farms.}, language = {en} } @article{KaemperBergBegemannetal.1998, author = {K{\"a}mper, Klaus-Peter and Berg, U. and Begemann, M. and Hagemann, B.}, title = {Series production and testing of a micro motor. Serienfertigung und Pr{\"u}fung eines Mikromotors}, series = {Actuator 98 : 6th International Conference on New Actuators ; 17 - 19 June, 1998, Bremen, Germany ; conference proceedings / ed.: Hubert Borgmann ...}, journal = {Actuator 98 : 6th International Conference on New Actuators ; 17 - 19 June, 1998, Bremen, Germany ; conference proceedings / ed.: Hubert Borgmann ...}, publisher = {Messe Bremen}, address = {Bremen}, isbn = {3-933339-00-6}, pages = {552 -- 555}, year = {1998}, language = {en} }