Practical trainings, student assistants and theses

Computational fluid dynamics (CFD) is increasingly offering an alternative to experimental optimisation and improvement of both existing and new industrial processes or products, for which otherwise costly and time-consuming test and pilot plants are used. While the simulation of single-phase flows allows stable and reliable predictions, such numerical analyses for multiphase flows have so far only been validated and useful for selected cases due to their complexity and the large number of additional interactions.

In order to extend the applicability of numerical multiphase simulations, the Institute of Fluid Dynamics at the Helmholtz Centre Dresden-Rossendorf carries out experimental and numerical investigations in bubble columns in collaboration with the Institut de Mécanique des Fluides de Toulouse (IMFT) to better understand phase interaction phenomena. The current project focuses on the lateral lift force acting on millimetre-sized bubbles rising through a shear field, with particular interest in the influence of curved shear layers.

The objective of the proposed bachelor or master thesis is to performed direct numerical simulations at IMFT, Toulouse of well controlled configurations of a bubble (spherical or deformed) rising in a shear flow. The simulations will be compared against experiments performed at HZDR.

• Studies related to fluid dynamics (e.g. mechanical or process engineering, physics etc.)
• Experience in numerical simulation
• Good English or French language skills

• Working in a multidisciplinary and international team
• Place of work: IMFT in Toulouse
• Start: from March 2025
• Duration: approx. 6 months

Flowing foam is relevant to many different industrial applications, such as froth flotation in mineral processing, fire-extinguishing systems, or brewing beer and beverage production. In a scientific context, the rheological properties of foams are very complex and significantly different from those of Newtonian fluids such as water. As a result, despite numerous experimental and theoretical studies, the fluid dynamics of foams remain poorly understood.

This project focuses on a classical benchmark experiment: the flow around a cylindrical obstacle. To identify key parameters of flowing foam in this configuration, we use two unique radiographic measurement techniques. First, neutron radiography provides imaging measurements of the local liquid fraction of the flowing foam. Second, X-ray radiography with foam-tailored tracer particles allows to perform local velocity measurements in the flowing foam.

The following subtasks are mainly to be worked on:

• Assistance in preparing and performing the foam flow experiment in the X-ray laboratory at HZDR
• Analysis of the measurement data, including image processing and machine learning if applicable
• Documentation of the experiment and measurement results in written form

• Field of study: process engineering, fluid mechanics, or similar focus in chemistry or physics
• Experience with laboratory work, imaging measurement techniques or measurement data analysis is beneficial (e.g. using ImageJ, Matlab, Python)
• High motivation and interest in the subject
• Careful, structured and independent way of working
• Good oral and written communication skills in English or German
• Enjoyment of scientific work

• Working in a multi-disciplinary and international team
• Place of work: HZDR or TU Dresden
• Start: from January 2025
• Duration: min. 3 months
• Remuneration according to HZDR internal regulations

The application of phage surface display (PSD) technology has accelerated developments in the field of biomolecular sensors and materials science. A practical complement to this technology is Next-Generation Sequencing (NGS). In this combination, a more comprehensive view of biopanning rounds with a deep insight into the entire sequence space is made possible. It is possible to identify sequencing artefacts, determine sequence number and structure, recognize binding motifs and observe the evolution of the phage library over the course of an experiment. PSD in combination with biopanning is able to select candidates with high affinity and selectivity to the desired substrates from large peptide libraries. In practice, this specific enrichment of peptides leads to a reduction in library diversity. It should therefore be possible to better visualize this reduction in sequence space using data clustering methods in order to better understand distances between similar sequence families.
The student's task is to find suitable clustering methods for sequencing results from multiple phage display experiments and to apply these if necessary. It should be clear from the results to what extent the sequence space can be grouped into families and whether a mutation profile within and between these families is recognizable.

Prerequisite is a valid enrollment in a Master's program in bioinformatics, biotechnology, molecular biology, biochemistry, biology or a related natural science program. Furthermore:

• Interest in data cluster methods and bioinformatics
• Basic knowledge of bioinformatics, statistics, stochastics and clustering
• Experience with a programming language (e.g. Python, R, C, C++ or other)
• Ability to work independently and in a team

The topic is to be worked on as part of a Master's thesis in conjunction with a voluntary or mandatory internship. This results in a duration of 12 months. The duration can be extended or adjusted in consultation with the supervisor. We can offer you:

• An innovative multidisciplinary research environment related to relevant issues in resource technology
• Supervision by experienced scientists
• Practical experience in the field of bioinformatics and directed evolution

HZDR develops and operates two high-intensity lasers (DRACO and PENELOPE) as drivers for plasma-based accelerators — a novel concept for compact sources delivering ultra-short pulses of high-energy ions and electrons. We experimentally investigate plasma-based acceleration from the physical fundamentals to the application. - e.g., for free-electron lasers, as particle sources for radiobiological studies, or for neutron sources.
In order to realize such sources, a constant development and improvement of the laser system is paramount. One major point of interest for every high energy laser system is a well-defined beam shape. Within the scope of this work the already existing beam shaping at the PENELOPE laser on the basis of serrated apertures needs to be analyzed both numerically and experimentally. Alternative concepts to achieve suitable beam shaping capabilities shall be compared.

Focus of the work:

• Modeling of optical diffraction on serrated apertures, e.g., using Python
• Experimental verification of the diffraction pattern
• Data acquisition (near field, far field, propagation)
• Optimization of the shape of serrated apertures
• Introduction to alternative beam shaping concepts
• Data analysis and documentation

• Studies in Physics, Physical Engineering (or a comparable field of study)
• Interest in optics and laser physics-
• Interest in experimental work
• Interest in numerical methods in optics

• Duration: at least 3 months, the topic can easily be expanded into a thesis
• Start: anytime
• Workplace: Helmholtz-Zentrum Dresden – Rossendorf

HZDR develops and operates two high-intensity lasers (DRACO and PENELOPE) as drivers for plasma-based accelerators — a novel concept for compact sources delivering ultra-short pulses of high-energy ions and electrons. We experimentally investigate plasma-based acceleration from the physical fundamentals to the application.- e.g. for free-electron lasers, as particle sources for radiobiological studies, or for neutron sources.
In order to realize such sources, constant development and improvement of the laser system is paramount. The scope of this work lies in the analytical design, its optimization and the realization of a regenerative amplifier design. Such an amplifier is considered to replace one of the preamplifier stages (HGBA II) of the PENELOPE laser system. The amplifier design aims at >100 mJ of pulse energy at a repetition rate of 10 Hz, while the bandwidth supports laser pulses with a pulse duration of <150 fs.

Focus of the work:

• Design/modeling and optimization of the laser resonator using software support (e.g. RP Resonator or own script)
• Subsequent realization of the regenerative laser amplifier in the laboratory
• Data acquisition (near field, far field, spectrum)
• Optimisation of the laser pulse bandwidth and output energy
• Data analysis and documentation

• Studies in Physics, Physical Engineering (or a comparable field of study)
• Interest optics and laser physics
• Interest in experimental work

• Duration: at least 3 months, the topic can easily be expanded into a thesis
• Start: anytime
• Workplace: Helmholtz-Zentrum Dresden – Rossendorf

The research project ‘Development of tailor-made peptides for the treatment of polymers before the metallization of plastics’ aims to develop a biomolecule-based system that enables the metallization of high-quality engineering plastics. Using phage surface display technology (PSD), peptides are selected and their binding behavior is characterized using suitable technologies to quantify the surface interaction. Our industrial partner tests suitable peptide sequences in practical polymer coating and metallization experiments.

• Studying biotechnology, microbiology, chemistry, chemical engineering, or a comparable subject area
• Interest in practical, interdisciplinary research
• Knowledge of basic molecular biological and microbiological principles and working techniques
• Careful and independent way of working

• Work in an interdisciplinary and international team
• The workplace language is English
• Duration of the internship or thesis according to study regulations
• Start of work possible by February 2025 at the latest

The development of a multi-channel flow body sensor according to patent WO 2010/069307 A1 aims to quantify the gas content in flow-carrying components. A decisive advantage of this sensor lies in its optical measuring principle, which is based on fiber-optic coupling and the analysis of the light output signal. This avoids electrical potentials in the measuring area, offering significant advantages over electrical measuring methods (intrinsic safety), especially for explosive mixtures.

Preliminary tests at the Institute for Experimental Fluid Dynamics at the Helmholtz Center Dresden-Rossendorf on gas-liquid flows showed that a clear binarization of the sensor output signal can be achieved due to the capillary effects in narrow channels and the different refractive indices of the gas and liquid phases. Building on previous work with a single-channel sensor prototype based on a polymer optical fiber (POF) with a diameter of 1 mm, the following tasks must be completed as part of further research.

Tasks:

• Adjusting the POF diameter to 1.5 mm in the single-channel configuration.
• Conducting experimental investigations of the new single-channel prototype using the already developed test system and evaluation programs.
• Designing a multi-channel sensor body for gas content measurements in the system.
• Developing a transition adapter to optimize the flow distribution between the DN10 flow pipe and the sensor body.

• Students majoring in fields such as process engineering, mechanical engineering, or chemical engineering.
• Interest in fluid mechanics and the development of measurement technology.
• Experience with 3D CAD tools.
• Basic knowledge of Python programming

Start date: 01.01.2025
Duration: according to the respective study regulations

Die Abteilung Finanzen, Finanzcontrolling und Drittmittel ist für das Finanzmanagement des Helmholtz-Zentrum Dresden-Rossendorf verantwortlich. Im Bereich Rechnungswesen (Haupt-, Banken-, Debitoren-, Kreditoren- und Anlagenbuchhaltung) wird Ihre Hilfe benötigt.

Ihre Aufgaben:

• Unterstützung (SAP) bei der Erfassung von Geschäftsvorfällen
• Unterstützung (SAP) bei der Stammdatenpflege, insbesondere Kreditoren
• Sonstige Unterstützungstätigkeiten

• Begonnenes Studium der Wirtschaftswissenschaften
• Erste Kenntnisse in den Grundlagen des Rechnungswesens (Buchführung, Kosten- und Leistungsrechnung)
• Selbstständige und verantwortungsvolle Arbeitsweise

• Arbeitsbeginn ab sofort
• Mindestens 6 Monate
• Tätigkeitsort: Standort Dresden-Rossendorf

Wir bieten Ihnen die Möglichkeit, im Studium Erlerntes praxisnah umzusetzen! Es erwarten Sie ein
motiviertes und kollegiales Arbeitsumfeld, tatkräftige Unterstützung bei der Umsetzung Ihrer Aufgaben sowie spannende Einblicke in die finanztechnische Schaltzentrale unseres Forschungsstandortes.

At Helmholtz-Zentrum Dresden-Rossendorf (HZDR), over 1,500 employees from more than 70 nations are conducting cutting-edge research in the fields of ENERGY, HEALTH, and MATERIALS to address the major challenges facing society today.
The Center for Advanced Systems Understanding (CASUS), founded in Görlitz in 2019, is a German-Polish interdisciplinary research center focusing on data-intensive digital systems.
CASUS offers student internships in a wide range of scientific fields. You are welcome to apply and join CASUS if you are interested in gaining knowledge in the following research areas:

• Theoretical Chemistry
• Earth System Science
• Systems Biology
• Digital Health
• Computational Radiation Physics
• Theory of complex systems
• Dynamics of Complex Living Systems
• Machine Learning for Infection and Disease

• Student in computer science, physics, chemistry, or related fields
• Student already enrolled at the university in Germany, Poland or Czech Republic (close exchange and attendance in the office preferable and combined with the moblie working from Germany combinable)
• Eager to learn new skills
• Strong motivation to work in a collaborative environment
• Preliminary experience in code development is an advantage
• Excellent communication skills in English and/or German or Polish

• A vibrant research community in an open, diverse and international work environment
• Scientific excellence and extensive professional networking opportunities
• A wide range of qualification opportunities
• We support a good work-life balance with the possibility of part-time employment, mobile working and flexible working hours
• Either an immediate start or a start in 2024 is possible

1D- und 2D-Ramanspektroskopische Meßreihen oder auch Maps liefern detaillierte ortsaufgelöste chemische Informationen über die untersuchten Proben. Damit kann z. B. die Komponentenverteilung in Stoffgemischen quantitativ bestimmt oder die Homogenität einphasiger Proben gezeigt werden. Andererseits lassen sich lokale Strukturveränderungen, Spannungszustände, Stapelfolgenänderungen in 2D-Materialien und Punktdefekte charakterisieren. Voraussetzung dabei ist eine möglichst engmaschige Datenerfassung bis hin zur Auflösungsgrenze der verwendeten Laserstrahlung sowie eine große Anzahl an Messpunkten. Mit modernen Spektrometern sind Messzeiten im Sekundenbereich gut realisierbar. Die Umsetzung der spektroskopischen in eine chemische Information erfordert dann die Extraktion von Parametern wie Schwingungsfrequenz, Intensität und Linienbreite durch Spektrenanpassung. Die Gerätesoftware bietet dafür nur eingeschränkte Möglichkeiten.
Im Rahmen einer Graduierungsarbeit oder Hilfstätigkeit soll in Zusammenarbeit mit dem HZDR-Rechenzentrum ein Auswertealgorithmus für die automatisierte Auswertung von 1D- und 2D-Ramanspektroskopischen Meßreihen entwickelt, an Beispielen getestet und dokumentiert werden.

1. Studium der Werkstoffwissenschaften, Physik oder Chemie
2. Interesse, Freude und Befähigung für wissenschaftliche Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Sehr gute Englisch-Kenntnisse

Die Arbeit ist in die umfangreichen Aktivitäten der Abteilung Nanoelektronik (FWIO) zu 2D-Werkstoffen eingebettet. Sie kann jederzeit aufgenommen werden.

Background:

Currently, there is a broad discussion whether ventilation by frequent window opening is sufficient for providing a sufficient amount of fresh air or if technical air purification devices based on e.g. HEPA filters are better solutions for public spaces. Furthermore, there is another discussion ongoing, whether a well-guided laminar flow or a high degree of mixing within a room is more beneficial. The latter, on the one hand distributes the potentially virus-laden aerosols in the whole room, but on the other hand reduces the peak concentrations of these aerosols clouds by magnitudes.

Objectives:

The objective is to perform aerosol propagation experiments and to estimate the potential aerosol inhalation of people in dynamic situations. To achieve this, an aerosol generator will be used in a demonstrator room under different flow conditions. The data from different scenarios will be processed in order to obtain a transference function that can relate the aerosol source with the aerosol receivers.

Tasks:

• Literature survey
• Aerosol experiments in different scenarios.
• Post-processing of the results.

• Student of natural sciences or engineering
• Willingness to conduct experimental work

Duration:

4-6 months

Remuneration:

According to HDZR guidelines

Wir beschäftigen uns mit der Entwicklung von PET-Radiotracern, die Rezeptoren im Tumormikromilieu (TME = tumor microenvironment) für die Diagnostik und Therapie von Krebs sichtbar machen. Dazu werden geeignete tumoraffine Leitstrukturen identifiziert (niedermolekulare organische Moleküle, Peptide und Peptidomimetika), synthetisiert und mit einem geeigneten Radionuklid kovalent (z. B. Fluor-18, Iod-123) oder über einen Chelator (z. B. Gallium-68, Lutetium-177) markiert. Diese Radioliganden werden in vitro an Tumorzelllinien und in vivo im Tiermodell hinsichtlich einer Anwendung in der Nuklearmedizin getestet. Langfristiges Ziel ist die Translation der entwickelten Radiotracer in die Klinik als Diagnosewerkzeug (PET/CT) oder nach Markierung mit einem Beta- oder Alphastrahler für die Endoradiotherapie von Tumorerkrankungen.
Im Rahmen eines Studentenpraktikums oder einer Bachelor- oder Masterarbeit sollen organische Wirkstoffmoleküle synthetisiert und für eine anschließende radiochemische Markierung modifiziert werden. Die neuen Radioliganden werden dann biologisch in vitro und in vivo untersucht.

• Studium der Chemie
• Gute Noten in organischer Synthesechemie
• Fähigkeit sich in ein interdisziplinäres Wissenschaftler-Team einzugliedern
• Bereitschaft zum Umgang mit Radioaktivität
• Gute Kenntnisse der deutschen und englischen Sprache

• Beginn nach Absprache jederzeit möglich
• Praktikumsdauer mind. 4 Wochen, mit möglichst täglicher Anwesenheit

Turmkraftwerke stellen die neueste Generation von Anlagen zur solarthermischen Elektroenergieerzeugung dar (s. Abbildung). Großflächige Spiegelanordnungen konzentrieren Sonnenlicht auf einen zentralen Absorber, wo es in Wärmeenergie umwandelt wird, die dann auf ein Wärmeträgermedium übertragen wird. Gegenüber der Photovoltaik hat die Solarthermie den inhärenten Vorteil, Energie zu speichern und bei Bedarf bereit zu stellen. Die Herausforderung für die weitere Erhöhung des Wirkungsgrades von Solarkraftwerken besteht in der Entwicklung von Werkstoffen mit einer Temperaturstabilität bis zu 800 °C an Luft.
Im Rahmen von Graduierungsarbeiten und Hilfstätigkeiten sollen thermisch stabile Beschichtungen für die Kernkomponenten von Solarturmkraftwerken entwickelt und getestet werden. Dabei kommen modernste in situ und ex situ Methoden wie Magnetronsputtern, Ellipsometrie, UV-vis-NIR-FTIR-Reflektometrie und Ramanspektroskopie zur Anwendung.
Zu diesem Themenbereich werden u. a. die folgenden Aufgabenstellungen angeboten:
i) Schichtabscheidung und Optimierung der optischen und elektrischen Eigenschaften von transparenten leitfähigen Oxiden für Solarkraftwerke;
ii) Entwicklung von neuartigen Absorber- und Wärmespeicherwerkstoffen für Solarkraftwerke;
iii) Design und Simulation von solarselektiven Beschichtungen für Solarkraftwerke.

Zur Charakterisierung der untersuchten Materialien stehen modernste in situ und ex situ Analysemethoden zur Verfügung. Die Arbeiten können jederzeit aufgenommen werden.

1. Studium der Werkstoffwissenschaften, Physik oder Chemie
2. Interesse, Freude und Befähigung für experimentelle wissenschaftliche Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Sichere Englischsprachkenntnisse (fließend oder besser)

Internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung