Fak. 3 Prozesswissenschaften

1491 Items

Recent Submissions
Experimental investigation of a cascaded organic Rankine cycle plant for the utilization of waste heat at high and low temperature levels

Linnemann, Matthias ; Priebe, Klaus-Peter ; Heim, André ; Wolff, Carsten ; Vrabec, Jadran (2020-01-14)

A power plant with two cascaded organic Rankine cycles (CORC) to exploit waste heat from a 800 kWe combined heat and power plant, fueled by biogas, is designed and tested. Heat from the exhaust gas is utilized with a high temperature organic Rankine cycle (HT-ORC), where toluene is employed as a working fluid. The heat discharged from the HT-ORC as well as heat from the engine coolant and addit...

Thermal degradation of citrus pectin in low-moisture environment - Influence of acidic and alkaline pre-treatment

Einhorn-Stoll, Ulrike ; Kastner, Hanna ; Urbisch, Alexandra ; Kroh, Lothar W. ; Drusch, Stephan (2018-02-21)

Pectin powder is degraded during storage and transport by demethoxylation and depolymerisation. The degradation mechanisms and especially the influence of pre-treatments on the degradation reactions are not completely understood. In this study, commercial citrus pectin was modified by either acidic or alkaline demethoxylation. The modified pectins, as well as the commercial pectin, were thermal...

Modification and physico-chemical properties of citrus pectin – Influence of enzymatic and acidic demethoxylation

Einhorn-Stoll, Ulrike ; Kastner, Hanna ; Hecht, Theresia ; Zimathies, Annett ; Drusch, Stephan (2015-06-04)

Aim of the present study was to investigate the effect of the method of demethoxylation on the particle structure and techno-functional properties of pectins with different degree of methoxylation and distribution of free carboxyl groups. Two groups of model pectins, one with 57% and one with 42% degree of methoxylation have been prepared from one single commercial pectin. Modifications were pe...

Thermally induced degradation of citrus pectins during storage – Alterations in molecular structure, colour and thermal analysis

Einhorn-Stoll, Ulrike ; Kastner, Hanna ; Drusch, Stephan (2013-08-15)

Commercial citrus pectins (17 samples from 3 different suppliers) were stored at 60 °C and 80% humidity for two weeks. Molecular parameters (galacturonan content, degree of methoxylation, intrinsic viscosity), colour and behaviour in thermal analysis (DSC and TG) were tested and the results were compared with those of model pectins prepared under laboratory conditions from a previous study. Whe...

Evaluation of different pre-treatments of chromium leather waste and their use in biogas production

Scaraffuni Gomes, Carolina (2020)

The worldwide economic importance of the leather industry is undeniable, as it converts a by-product of the meat industry, the hides, into a value-added product. However, processing of leather generates thousands of tons of new solid waste annually and, unlike hides, this waste has a low biodegradability. Usually, the tanning process is carried out using basified trivalent chromium salts. As a ...

MOSAICmodeling PlantDesign

Fillinger, Sandra (2020)

Considering the volatile macro-economic environment aggravating competitiveness in the increasingly globalizing market the most important challenge facing industrial companies is to achieve an innovation lead with high quality and reliability with shortened innovation cycles. For the entire life cycle of chemical plants, several stakeholders, such as owners, operators, vendors, and contractors,...

Continuous on-line tar monitoring in hot process gases from biomass gasification by means of fluorescence spectroscopy

Borgmeyer, Julian (2020)

Tar and tar related problems remain the foremost obstacle in development and especially in the implementation of gasification technologies into today’s energy supply systems. Tar-forming polycyclic aromatic compounds (PAC) are by-products of most high temperature thermochemical conversion processes of biomass. Further advances in technology development depend on reliable analytical methods to a...

Enzymatic hydrolysis of pea protein: Interactions and protein fractions involved in fermentation induced gels and their influence on rheological properties

Klost, Martina ; Giménez-Ribes, Gerard ; Drusch, Stephan (2020-02-24)

In the light of changing nutritional trends and recommendations, yoghurt style gels from plant proteins are a promising way to incorporate relevant amounts of plant derived proteins into the diet. However, in order to attain a high level of consumer acceptance, a thorough understanding of rheological behaviour, involved protein fractions and relevant interactions is mandatory in order to later ...

Atomic force microscopy-based nanoscopic studies of epoxy/boehmite nanocomposites

Ghasem Zadeh Khorasani, Media (2020)

Development of lightweight parts made of fiber-reinforced polymer composites for aerospace and automotive industry has been focus of many studies over the past several decades. Nanofillers added to the epoxy matrices used in such composite parts results in remarkable improvement of matrix-dominated properties. Formation of interphases between inorganic nanofillers and polymer matrices is usuall...

Impact of sodium ions on material properties, gelation and storage stability of citrus pectin

Kastner, Hanna ; Einhorn-Stoll, Ulrike ; Fatouros, Alexandra ; Drusch, Stephan (2020-02-07)

Material properties, gelation and storage stability of demethoxylated pectin samples strongly varied in dependence on the applied modification method. It was assumed that the content of sodium ions and their resulting electrostatic interactions with free carboxyl groups were crucial for these differences. Sodium ions were widely removed by acidic modification but added during alkaline and enzym...

Influence of enzymatic and acidic demethoxylation on structure formation in sugar containing citrus pectin gels

Kastner, Hanna ; Einhorn-Stoll, Ulrike ; Drusch, Stephan (2018-10-18)

Aim of the present study was to investigate the impact of different demethoxylation methods and the co-occuring side effects on the molecular properties and structure formation in pectin gels. A high-methoxylated citrus pectin (HMP) was demethoxylated using either hydrochloric acid or pectin methylesterases of plant (pPME) or fungal (fPME) origin. pPME treatment causes a more block-wise distri...

Structure formation in sugar containing pectin gels - Influence of gel composition and cooling rate on the gelation of non-amidated and amidated low-methoxylated pectin

Kastner, Hanna ; Einhorn-Stoll, Ulrike ; Drusch, Stephan (2017-06-21)

Gel structure formation and gel properties of low-methoxyl pectin (LMP) and low-methoxyl amidated pectin (LMAP) with similar degree of methoxylation have been investigated by oscillatory rheological measurements. The gelling process was examined in a sugar-acid environment matching the conditions in jams and jellies. Factors studied included cooling rate, calcium content and pH. Parameters deri...

Structure formation in sugar containing pectin gels – Influence of tartaric acid content (pH) and cooling rate on the gelation of high-methoxylated pectin

Kastner, Hanna ; Kern, Karla ; Wilde, R. ; Berthold, Almuth ; Einhorn-Stoll, Ulrike ; Drusch, Stephan (2013-07-05)

The aim of the study was the application of a recently published method, using structuring parameters calculated from dG′/dt, for the characterisation of the pectin sugar acid gelation process. The influence of cooling rate and pH on structure formation of HM pectin gels containing 65 wt.% sucrose were investigated. The results show that the structure formation process as well as the properties...

Structure formation in sugar containing pectin gels – Influence of Ca2+ on the gelation of low-methoxylated pectin at acidic pH

Kastner, Hanna ; Einhorn-Stoll, Ulrike ; Senge, Bernhard (2011-09-14)

A new method for the examination of the pectin gelation process is presented as a complementation of the most common determination of the gelling point (cross-over of G′ and G″) from oscillation measurements. It is based on the first derivation dG′/dt from oscillation measurements (named as structuring velocity), and defines an initial as well as a critical structuring temperature. These allow ...

Comparison of Molecular Parameters; Material Properties and Gelling behaviour of Commercial Citrus Pectins

Einhorn-Stoll, Ulrike ; Kastner, Hanna ; Senge, Bernhard (2012-03-09)

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New Parameters for the Examination of the Pectin Gelation Process

Kastner, Hanna ; Einhorn-Stoll, Ulrike ; Senge, Bernhard (2012-03-09)

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MiR‐375‐mediated suppression of engineered coxsackievirus B3 in pancreatic cells

Pryshliak, Markian ; Hazini, Ahmet ; Knoch, Klaus ; Dieringer, Babette ; Tolksdorf, Beatrice ; Solimena, Michele ; Kurreck, Jens ; Pinkert, Sandra ; Fechner, Henry (2019-11-07)

Coxsackievirus B3 (CVB3) has potential as a new oncolytic agent for the treatment of cancer but can induce severe pancreatitis. Here, we inserted target sequences of the microRNA miR‐375 (miR‐375TS) into the 5′ terminus of the polyprotein encoding sequence or into the 3′UTR of the CVB3 strain rCVB3.1 to prevent viral replication in the pancreas. In pancreatic EndoC‐βH1 cells expressing miR‐375 ...

Kinetische Parameteridentifikation und Modelldiskriminierung am Beispiel der nassen Oxidation von Thiosulfat

Holz, Stephan ; Stewers, Lennart ; Thielert, Holger ; Guetta, Zion ; Repke, Jens‐Uwe (2019-12-02)

In der Kokereitechnik fallen belastete Abwässer an, die effizient behandelt werden müssen, um die Umwelt nicht zu belasten und den gesetzlichen Verordnungen gerecht zu werden. Hierzu ist ein genaues Prozessverständnis notwendig. Aufgrund der Vielzahl an möglichen Modifikationen nehmen Schwefelverbindungen eine Sonderstellung ein, weswegen die Kenntnis der verschiedenen Reaktionspfade und ‐kinet...

Thermodynamic reaction control of nucleoside phosphorolysis

Kaspar, Felix ; Giessmann, Robert T. ; Neubauer, Peter ; Wagner, Anke ; Gimpel, Matthias (2020-01-07)

Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose‐1‐phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed th...

Investigation of the Degradation of Chelate Complexes in Liquid Redox Desulfurization Processes

Holz, Stephan ; Köster, Peter ; Thielert, Holger ; Guetta, Zion ; Repke, Jens-Uwe (2020-01-22)

Metal complexes such as Fe‐EDTA, which are used as pseudo‐catalysts or oxygen carriers in wet oxidative desulfurization processes, are subject to a degradation mechanism that significantly influences the economics of such processes. Therefore, this study presents a methodology for determining the degree of degradation during the reactive hydrogen sulfide absorption in a Fe‐EDTA solution within ...