PhD students of the Department of Natural Sciences

"Just to make it clear - my research is on water!" (Roman Grimmig, PhD student in the Department of Natural Sciences)

Research has a long tradition in the Department of Applied Sciences. In the following, we give a small insight into the variety of topics covered by the research work of our doctoral students and list by whom they are supervised at the H-BRS. Further links lead to research institutes, cooperation partners, publications, etc. (Selection, status September 2020).

 

Abla Alzagameem, TREE, Project BiopolymerModell
In order to do without petroleum-based resources, recent research is trying to develop green materials from sustainable resources for future chemicals, fuels, polymers and fibres. The second most common biopolymer on earth (after cellulose) is lignin, and this could replace fossil fuel resources in the future. Lignin separates cellulose and hemicellulose in the plant cell wall. It is largely produced as a by-product of pulp treatment and burned to produce energy that is used in the rest of the pulping process. Especially exciting is the polyphenolic nature of lignin with antioxidative and antimicrobial activity. Doctoral student Abla Alzagameem has obtained several types of lignins (Kraft, Organosolve, wood-based and grass-based lignin) in her research. She also tested the antioxidant and antimicrobial activity and polymerized the active lignin types with cellulose and chitosan for food packaging applications. Finally, she tested the antioxidant and antimicrobial activities of the films against pathogens that spoil food. Supervisor: Prof. Dr. Margit Schulze
 


 

Patrick Babczyk
PhD student Patrick Babczyk is investigating the influence of secreted extracellular vesicles (exosomes) from stem cells differentiating towards fat cells on endothelial cells. These are cells that form the inner layer of blood vessels. He hopes to find a starting point for preventing the development of atherosclerosis, the pathological narrowing of arteries, and the associated consequences such as heart attack or stroke.
Supervisor: Prof. Dr. Edda Tobiasch


 

Jennifer Braun, ISF
PhD student Jennifer Braun takes a closer look at the sniffer dog as a "detector" for volatile organic compounds (VOCs). Due to their highly sensitive olfactory organ, sniffer dogs have the special ability to sniff drugs, explosives, humans or animals by means of their scent. But how sensitive is the dog and how reliable is its detection? To get to the bottom of this question, PhD student Jennifer Braun is working on methods for the quality-assured quantification of VOCs, which primarily involve instrumental analysis but also the sniffer dog. Supervisor: Prof. Dr. Peter-Michael Kaul


 

Rene Breuch, ISF
Unwanted bacteria in the food industry are a problem, and detecting them is a particular challenge. PhD student Rene Breuch is investigating how surface-enhancing Raman spectroscopy (SERS) can be used to detect such bacteria in time. In doing so, he detects and differentiates spoilage bacteria through the targeted development of durable SERS substrates based on gold nanoparticles, suitable sampling methods and multivariate statistics.
Supervisor: Prof. Dr. Peter Kaul.

 


Dominik Büchner,  TREE, Projekt Hybrid-KEM
Biocompatible, synthetic bone replacement materials are a good alternative to the patient's own bone tissue, as they show fewer rejection reactions, are available in large quantities and can be modified if necessary. In the Hybrid KEM project, doctoral student Dominik Büchner is developing a novel bone substitute material that comes as close as possible to natural bone and is also therapeutically active. To this end, he is optimizing the synthesis of the bone mineral hydroxyapatite and chemically modifying polysaccharides derived from algae with bisphosphonate agents, which are used for bone regeneration.
Supervisor: Prof. Dr. Margit Schulze.

 

 

Xuan Tung Do, TREE, Projekt BiopolymerModell
Doctoral student Xuan Tung Do is investigating how to turn a centuries-old waste product into a material with superpowers. Many objects of daily life are still produced in some form from fossil raw materials such as crude oil. Since these raw materials are only available in limited quantities, scientists are looking for sustainable alternatives. To this end, doctoral student Xuan Tung Do is investigating a waste material from the paper industry - lignin. It is a complex biopolymer and must first be characterised using different analytical and statistical methods before it can be used as a direct substitute for crude oil. As part of his doctoral thesis, Do determines the molecular weight of the biopolymer using different spectroscopic as well as 1D and 2D chromatographic methods.
Supervisor: Prof. Dr. Margit Schulze.


 

Benedikt Eger
Betreuung: Prof. Dr. Steffen Witzleben

 

 

Philipp Gillemot, TREE, Projekt REDEX
High-quality drinking water is one of the most widely used resources in industry, agriculture and private households. However, the wastewater produced during use requires complex treatment, as it can be contaminated by a wide range of chemicals. In order to break down potentially harmful contaminants, so-called oxidation processes are widely used in sewage treatment plants. However, certain compounds, including pesticides and drug residues, are very stable and cannot be broken down by oxidative means - they remain persistent in the environment. Therefore, doctoral student Philipp Gillemot is investigating to what extent the reductive treatment of contaminated water can be used as an efficient alternative to render such critical water constituents harmless. One focus is on the development of suitable catalyst materials in order to fully exploit the potential of this novel treatment method.
Supervisor: Prof. Dr. Steffen Witzleben

 

 

Nektaria Giotis
Doctoral student Nektaria Giotis researches a rare genetic metabolic disorder, the HSD10 defect, which was first identified in 2000. Under the supervision of Prof. Dr. Thomas Lücke of the Ruhr-University Bochum and Prof. Dr. Jörn Oliver Sass of the H-BRS she is working on a medical doctoral project. The aim is to obtain information on the course of the disease and on the relationship between genotype and phenotype, and to investigate possible influences on the steroid balance. Thus, Nektaria Giotis contributes to a better understanding of HSD10 disease and helps to improve diagnosis and prognosis.
Supervisor: Prof. Dr. Jörn Oliver Sass

 

 

Roman Grimmig, TREE, OzonArray, ReDeX
It is an absolute matter of course for us that we get water of perfect quality from the tap. In the context of drinking water treatment, oxidative processes such as ozonation are often used, which effectively remove potentially harmful water constituents (e.g. germs) and thus disinfect the water. For this purpose, PhD student Roman Grimmig is developing a modular ozone generator that enables this oxidative treatment option to be tailored to the specific requirements. In order to be able to reliably exclude undesirable disinfection by-products arising in the process, a combined oxidative and reductive treatment in conventional tap water is being evaluated.
Supervisor: Prof. Dr. Steffen Witzleben

 

 

Thomas Havelt, EFRE-Projekt
Plastic packaging is usually made from petroleum and contains chemicals that prevent the packaging from decomposing and significantly increase its shelf life. Thomas Havelt is researching plant-based alternatives for these chemicals, some of which are hazardous to health and the environment, with the aim of developing more environmentally friendly packaging. Thomas Havelt is a scholarship holder of the Faculty of Applied Sciences and works in the EFRE project (Bio-based materials and packaging materials, sub-project Bioactive additives) at the H-BRS site in Rheinbach. Supervisor: Prof. Dr. Michaela Schmitz.
Link to an interesting podcast with Thomas Havelt.

 

 


Sarah Heß
Sarah Heß' research goal is the detection of DNA profiles ("genetic fingerprints") from fallen single hairs. In most cases, they carry only a small amount of DNA, which has disintegrated into very short pieces. In order to deduce the cause of the trace from the hair, the analysis of this trace type requires a number of highly sensitive detection methods, which are improved at the H-BRS and optimized for application to micro traces.
Betreuung: Prof. Dr. Richard Jäger

 

 

Dorothee Hielscher
Large bone defects after accidents or tumour removal can make the use of bone transplants necessary. The discovery of so-called induced pluripotent stem cells (iPS) has paved the way for new therapeutic options. In order to make the potential use of iPS in bone transplants in patients as safe as possible, the cells need to be precisely characterised. Therefore, PhD student Dorothee Hielscher investigates and compares the potential of induced pluripotent stem cells for osteogenesis (bone formation). A special focus is on specific receptors that can be stimulated/inhibited by certain substances and could thus contribute significantly to the improvement of bone transplantation in the future.
Supervisor: Prof. Dr. Edda Tobiasch

 

 

Jana Hinz, ISF
N-nitrosamines are partly highly volatile compounds that can be formed in many different industrial processes and are classified as carcinogenic. Due to their high health risk, it is of acute interest to develop reliable, sensitive and mobile systems for the detection and quantification of N-nitrosamines. PhD student Jana Hinz is working on the development of a GC-FAIMS system, a measuring device for the rapid analysis of N-nitrosamines. This system is to be applied in various branches of industry. Compared to common methods, the GC-FAIMS offers the advantage of being fast, field applicable and cost efficient.
Supervisor: Prof. Dr. Michaela Wirtz


 

Amadeus Janotta, ISF
Terrorists repeatedly use the explosive triacetone triperoxide (TATP) in attacks because the starting materials for it are easily accessible and TATP is easy to synthesize. Identifying and sampling TATP is a challenge for security authorities because the explosive is sensitive to shock, heat, friction and vibration. This is why Amadeus Janotta is researching a disposable sensor made of electrospun polymer fibers. Since TATP sublimates (it changes directly from solid to gas), it can react in gaseous form with the substances contained in the polymer fibers in a color change visible to the naked eye. The aim of Amadeus Janotta's doctoral thesis is to develop a contact-free, fast and energy-autonomous on-site identification method for the detection of TATP. Since 2019, Amadeus Janotta is a scholarshipholder of the Institute of Safety and Security Research.
Supervisor: Prof. Dr. Peter-Michael Kaul

 

 

Lil Klaas
Doctoral student Lil Klaas, with the support of the Association for Pediatric Metabolic Disorders (APS), is investigating rare genetic defects in selected enzymes (aminoacylases) that lead to congenital metabolic disorders. The aim of her research is to gain a better understanding of the mechanisms underlying such disorders and thereby create a basis for therapeutic approaches. Lil Klaas is a fellow of the Equal Opportunities Office and conducts research at the H-BRS site in Rheinbach.
Supvervisor: Prof. Dr. Jörn Oliver Sass


 

Daniel Klein, ISF
Raw meat quickly shows bacterial infestation. If the infected meat is consumed, it can be a health hazard above a certain amount. Daniel Klein therefore wants to make contaminations (e.g. bacteria) visible on complex surfaces (e.g. meat). He combines spectroscopic data from IR and Raman spectroscopy from the same measuring regions to show where contaminations can be found. The combination of the two methods should increase the information content of the data set and at the same time reduce the error rate in contamination detection. Since 2018, Daniel Klein is scholarshipholder of the Institute of Safety and Security Research (ISF).
Supervisor: Prof. Dr. Peter-Michael Kaul


 

Stephanie Klein, ISF
Due to the increasing scarcity of raw materials, the search for alternative renewable raw materials and their recycling is becoming more and more important in industry. The research goal of PhD student Stephanie E. Klein is the production and optimisation of bio-based plastic coatings for construction chemical applications and for the production of packaging materials. She and her research group used the synthesized plastic coatings with different additives to improve the material scientific properties and analyzed them. Finally, homogeneous, flexible and antimicrobially more effective, bio-based plastic films could be produced.
Supervisor: Prof. Dr. Margit Schulze

 

 

Stephan Maurer, ISF
Improviced explosive device (IED) is often used in terrorist activities and are part of the threat in the global trouble spots. The protection of people and material therefore requires effective countermeasures. This also includes enabling security forces or military personnel to classify unknown substance finds as dangerous or non-critical with little time and logistical effort on site. In order to differentiate between explosive and non-explosive materials, the highly exothermic reaction that can be initiated in explosives can be used. This results in radiation emissions as well as in local pressure and temperature increases. The measurement of these reaction effects and the requirement for mobile, easy-to-use and robust analysis are made possible by a system developed by PhD student Stephan Maurer, which stimulates samples in the single-digit mg range to undergo chemical conversion by rapid heating on microstructured heaters.
Supervisor: Prof. Dr. Peter Kaul
 

 

Michael Meurer
Michael Meurer's research interest gets under the skin. He deals with Transdermal Therapeutic Systems = TTS. These are drug patches that are stuck onto the skin and release active substances from a depot into the body. These patches are used to treat severe pain or diseases such as Alzheimer's and Parkinson's disease. Unfortunately, the adhesion of these plasters to stainless steel plates is unfortunately tested as a standard method far removed from the application. On human skin, however, the adhesion can be quite different. That is why Michael Meurer is researching application-oriented test methods on artificial skin substrates in order to advance the further development of plasters. The goal is the adhesion of the entire patch to the skin over a period of up to one week. Since 2018, Michael Meurer is a scholarshipholder of the Institute of Technology, Resorce, and Energy-Efficient Engineering Further Information
Supervisor: Prof. Dr. Bernhard Möginger

 

 

Cassandra Moers, TREE
PhD student Cassandra Moers researches aluminium thick wires that are processed in a variety of electronic components, for example in sensors and control units of means of transport. Such electronic components are becoming increasingly important in the context of e-mobility and "assisted and autonomous driving". In daily use, aluminium thick wires are exposed to mechanical, thermal and electrical stresses and can fail over time, which can lead to a complete failure of the component. Therefore, doctoral student Cassandra Moers investigates and evaluates the reliability of the wire materials and simulates their application behaviour. The aluminum thick wires she is investigating have diameters of less than half a millimeter, which is about ten times thicker than a human hair.
Supervisor: Prof. Dr. Christian Dresbach
 

 

 

Matthias Muhr, ISF
Newly synthesized chemicals or products that pose an explosion hazard in pure form or as a mixture pose a safety risk if they are not sufficiently characterized and classified. Classically, such substances are characterized with a variety of conventional test methods that require the handling of relatively large sample quantities. The aim of Matthias Muhr's PhD project is to develop a test apparatus by sensory monitoring of these conventional methods, with which it is possible to carry out a more precise characterization of such substances. In doing so, the sample quantities are to be significantly reduced in order to significantly lower the safety risk during handling.
Since 2019, Matthias Muhr is a scholarshipholder of the Institute of Safety and Security Research. 
Supervisor: Prof. Dr. Gerhard Holl


 

 

Patrick Ottensmeyer
PhD student Patrick Ottensmeyer
is investigating how people with large bone defects and a need for transplants can be helped. He isolates human stem cells from fat and differentiates them into bone cells on a carrier material. Using "HOX" transcription factors, he hopes to define the best body region for stem cell harvesting. In addition, Patrick Ottensmeyer is trying to stimulate bone cell development and the formation of new blood vessels for the supply of the graft with specific receptors. The new system will be tested in cell cultures, bioreactors and preclinical applications. Since 2018, Patrick Ottensmeyer is  Further Information
Supervisor: Prof. Dr. Edda Tobiasch

 

 

 

 

 

Lukas Pschyklenk, Natural Sciences/ISF, Project "Optospin"
Liquid crystals are generally only known from displays (LCD). The extraordinary optical properties of these fascinating substances can be used for various applications. One of them is gas sensor technology. A special liquid crystalline phase, which is created by doping with optically active substances, reflects only a narrow wavelength range of the incident light back, similar to the wings of a butterfly. For the observer, the liquid crystal then appears in a very intense color. However, no dye is responsible for the color, only the structure of the liquid crystal. Through a chemical reaction of the dopant with a substance to be detected, this structure changes and with it the visible color immediately. For the detection of substances, PhD student Lukas Pschyklenk is developing a gas sensor that has no power consumption and can be read with the naked eye. The PhD project is linked to the BMBF project OptoSpin. The aim of the project is to find suitable dopants for selected safety-relevant substances and to improve the applicability of these sensors.
Supervisor: Prof. Dr. Peter Kaul

 

 

 

Julian Rech, TREE
Plastics have become an integral part of everyday life. In order to improve the mechanical properties of plastics and thus extend the range of applications, plastics are reinforced with fillers, for example with glass fibres, glass beads, carbon fibres etc. Doctoral student Julian Rech wants to model and verify the new mechanical properties of the resulting composite material in his research work. The new development of this model approach (Elementary Volume Concept) is based on the consideration of the adhesion between filler and matrix (plastic), which results in a better prediction of e.g. the stiffness of the composite material. These model results are important for designers and engineers for the construction of new plastic components for e.g. automotive, aerospace and safety related applications.
Supervisor: Prof. Dr. Bernhard Möginger
 

 


Jessica Rumpf
Awareness of the need for biodegradable/compostable and/or recyclable materials from renewable resources or biomass waste has increased significantly in recent years - sustainable packaging is more desirable than non-degradable packaging. Therefore PhD student Jessica Rumpf synthesizes new bio-based films or coatings for packaging purposes from cellulose derivatives. She is investigating lignin, a biopolymer with antioxidative and antimicrobial effects, which is produced in large quantities as a waste product in paper and cellulose production and has so far hardly been used as a material. If Jessica Rumpf succeeds in making lignin available as a raw material in reproducible quality, lignin-based components could replace some of the previously fossil-based substances in various packaging. Since 2019, Jessica Rumpf is a scholarship holder of the Equal Opportunities Office.
Betreuung: Prof. Dr. Margit Schulze 


 

Sara Schäfer, ISF
Due to its unique properties, ultrapure water serves as solvent or starting product for pharmaceuticals and is used to clean surfaces in the production of high-precision components in semiconductor manufacturing. Water quality monitoring is of utmost importance. For this reason PhD student Sara Schäfer develops an universal measuring instrument for quality monitoring of ultrapure water. It combines two standard methods of oxidation. The oxidation is performed by ozonation in combination with UV radiation. That leads to an advanced oxidation process and a significant increase in the oxidation power compared to conventional systems.
Supervisor: Prof. Dr. Peter Kaul

 

 

Daniel Schulke
In der Arbeitsgruppe „Inborn Errors of Metabolism“ beschäftigt sich Doktorand Daniel Schulke mit Bio-Katalysatoren (Enzymen), die vor allem in der Leber vorkommen und zum Beispiel an Entgiftungsprozessen beteiligt sind. Er erforscht genetisch bedingte Veränderungen dieser Enzyme nicht nur wegen der grundsätzlichen Bedeutung für ihre Eigenschaften, sondern auch, weil sie für den Stoffwechsel (Metabolismus) von Arzneistoffen relevant sein können. Das Forschungsvorhaben soll einen Beitrag dazu leisten, Grundlagen für eine individualisierte Pharmatherapie seltener Stoffwechselkrankheiten zu schaffen, im Sinne der Entwicklung hin zu einer personalisierten Medizin. Die Arbeit wird durch die Heinz und Heide Dürr Stiftung und Gottfried und Julia Bangerter-Rhyner-Stiftung unterstützt.
Betreuung: Prof. Dr. Jörn Oliver Sass  Further Information


 

Sarah Shoushrah
Betreuung: Prof. Dr. Edda Tobiasch

 

Jannika Staudt, Projekt BONARes-ORDIAmur (P6)
In addition to weather extremes and climate changes, other factors such as nutrient supply or other soil components have an influence on plant growth and food quality. Especially in regional and national apple cultivation, the repeated cultivation of apple trees (lat.: malus) on the same area leads to reduced growth, quality and yield losses. One then speaks of "apple replant disease" (ARD). A variety of factors are considered to be the cause, such as bioactive substances in the soil or the composition of microorganisms in the soil. Since soil treatment agents are largely banned by regulations, the symptoms are treated in a different way. In the research project "BONARes-ORDIAmur (P6)" PhD student Jannika Staudt identifies and characterizes tolerant and less tolerant rootstocks, i.e. root system and part of the stem. This should lead to plants being able to cope with the given conditions themselves due to their defence system and to farmers being able to avoid the use of soil treatment products.
Supervisor: Prof. Dr. Michaela Schmitz
 


 

Michael Stotter, IZNE
The German-Dutch project called "Food Protects" aims to reduce regional and surplus existing nitrate inputs from agriculture and to increase structural diversity in the agricultural landscape. To this end, PhD student Michael Stotter is working on the environmental impacts of the use of Miscanthus biomass in livestock farming. He focuses on the application of organic fertilizers from Miscanthus additions in an environmentally friendly and site-appropriate manner. The influence on the nitrogen and carbon dynamics and the interaction in the soil-plant system are in the foreground.
Supervisor: Prof. Dr. Martin Hamer

 

 

Philipp Swoboda, IZNE
Can stones be turned into bread? Ground stones have been used in agriculture for centuries. Many rocks contain essential plant nutrients and could therefore be used as natural fertilizers and soil conditioners. However, previous results are contradictory, as the effect depends strongly on the respective rock, soil and plant type. PhD student Philipp Swoboda is therefore investigating how and under what conditions rock flour can best be used in agriculture.
Supervisor: Prof. Dr. Martin Hamer


 

Christian Tonk
Osteoporosis (bone atrophy) is a systemic skeletal disease in which the bone substance is increasingly broken down. Basically, osteoporosis cannot be cured nowadays. Only the progression of the disease can be delayed by treatment. However, currently used drugs can have considerable side effects, making new target molecules useful for additional treatment strategies. Cathepsin K could be such a target molecule. Therefore, Christian Tonk is investigating a cathepsin K inhibitor for its influence on bone metabolism in order to test the capacity of the inhibitor as a future drug against osteoporosis.
Supervisor: Prof. Dr. Edda Tobiasch

 

 

Sarah Vermeeren, ISF
PhD student Sarah Vermeeren is developing a method for the detection of wart disease, which is caused by the potted fungus Synchytrium endobioticum (Schilb.) Perc. and is one of the most important pests of potatoes. It even has quarantine status in EU countries, i.e. infected areas are closed to potato cultivation for years. Early detection and containment of wart disease is therefore extremely important. Sarah Vermeeren uses thermodesorption gas chromatography-mass spectrometry (TD-GC-MS) and proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) to analyse the Volatile Organic Compound (VOC) profiles of potato plants, potatoes and residual soils with the aim of differentiating between healthy and infected status.
Supervisor: Prof. Dr. Peter Kaul

 

 

Katharina Walbrück, TREE, Projekt Biobasierte Produkte
The demand for ecological and sustainable insulation materials is growing, especially in view of the advancing climate change and dwindling fossil raw materials. Renewable raw materials represent a possible alternative to traditional insulation materials, as they are CO2-neutral compared to fossil raw materials. PhD student Katharina Walbrück is investigating the suitability of the giant Chinese reed Miscanthus x giganteus for use in insulating materials. Miscanthus is a fast-growing, perennial grass that binds 10 to 36 t CO2 per hectare and year during its growth.
Supervisor: Prof. Dr. Steffen Witzleben

 

 

Johannes Warmer, ISF
In his doctoral thesis, Johannes Warmer is working on the development of a sensor system for the detection of triacetone triperoxide (TATP), a highly explosive substance that has been used by terrorists for several attacks. In his work he is mainly concerned with so-called metal oxide semiconductor gas sensors, which are characterized by a very high sensitivity but low selectivity at low acquisition costs. In order to compensate for the disadvantage of low selectivity, the sensor performance has to be optimized by selecting suitable materials and operating modes of the sensor. Within the scope of the doctoral thesis, starting with the production of the actual sensor, the development of suitable signal processing strategies and the combination of different spectroscopic and electrical measuring methods are used to not only realize the suitability of such a sensor system, but also to formulate the underlying chemical surface reactions. The aim is to gain a deeper understanding of the actual sensory mechanism.
Supervisor: Prof. Dr. Peter Kaul

 

 

Markus Witzler, TREE
In the therapy of bone defects, implants are often used to accelerate and improve healing. A modern approach is a carrier material for bone cells, which simultaneously releases active ingredients and can be broken down by the body during the healing process. PhD student Markus Witzler is researching novel carrier materials based on agarose and calciumphosphat. Agarose, a renewable biopolymer, is chemically modified to release active ingredients in a controlled and delayed manner over a period of several days.These active substances should help stem cells to develop specifically towards bone cells. Supervisor: Prof. Dr. Margit Schulze