Helmholtz-Zentrum Dresden Rossendorf in Germany invites application for vacant PhD, Postdoc and Academic Positions, a Dresden-based research laboratory. It conducts research in three of the Helmholtz Association’s areas: materials, health, and energy.
Student internship, research assistant, school practical training, master/diploma thesis, compulsory internship (Id 407)
School practical training / Student practical training / Bachelor theses / Master theses / Diploma theses / Student Assistant / Holiday job / Compulsory internship / Volunteer internship / Research Assistant
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
- Matter under Extreme Conditions
- Systems Biology
- Digital Health
- Computational Radiation Physics
- Computational Quantum Many-Body Theory
- Mathematical Foundations of Complex System Science
- Dynamics of Complex Living Systems
- Machine Learning for Infection and Disease
You can also apply to join our administrative team as a student assistant.
Institute: CASUS
Contact: Dr. Mir Hosseini, Seyed Hossein, Mazur, Weronika
Requirements
- Student in computer science, physics, chemistry, or related fields
- 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
Conditions
- 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
Please submit your application (including a one-page cover letter, CV, academic degrees, transcripts, etc.) online on the HZDR application portal
Online application
Please apply online: english / german
Unterstützung bei Organisation und Kommunikation von Angeboten des Postdoc Center (Id 406)
Student Assistant
Das Postdoc Center ist die zentrale Anlauf- und Servicestelle für alle Fragen rund um die Nachwuchsförderung nach der Promotion. Unser Ziel ist es, den Nachwuchswissenschaftler*innen zu helfen, ihre persönlichen Stärken und Kompetenzen von Beginn an proaktiv und strategisch weiterzuentwickeln. Wir bieten dabei passgenaue Formate für eine außerfachliche Qualifizierung, Entscheidungsfindung und der nachfolgenden Planung und Durchführung weiterer Karriereschritte an.
Dabei suchen wir eine Unterstützung insbesondere bei organisatorischen und administrativen Aufgaben, wie Veranstaltungs- und Teilnehmendenmanagement. Darüber hinaus wünschen wir uns Unterstützung in der Kommunikation für z. B. Infoletter und Webseiten, sowie auch für Recherche-Arbeiten und Zuarbeiten für Berichte.
Zu den Aufgaben zählen:
- Teilnehmendenmanagement und Kommunikation von Workshops (sehr gute Englischkenntnisse zwingend erforderlich)
- Organisatorische Unterstützung
- Vorbereitung von Präsentationen und Unterlagen
- Aktualisierung von Webseiten
Institute: Department of Administration
Contact: Dr. Körösi, Veronika, Dr. Göttling, Janine
Requirements
- Studium aller Studienrichtungen
- Gute MS Office Kenntnisse
- Sehr gute bis fließende Englischkenntnisse
- Selbstständige und strukturierte Arbeitsweise
Conditions
Wir suchen Unterstützung zum nächstmöglichen Zeitpunkt bis Ende September 2024 für max. 19 Stunden pro Woche. Die Aufgaben können nur vor Ort am HZDR erfüllt werden. Wir freuen uns über Ihre Bewerbungsunterlagen (Anschreiben, Lebenslauf, etc.), die Sie bitte ausschließlich über unser Online-Bewerbungsportal einreichen.
Links:
Online application
Please apply online: english / german
Competitive bubble-particle attachment from a particle mixture in a model stirred cell (Id 405)
Master theses / Diploma theses / Compulsory internship
Flotation is a widely used technique worldwide to extract valuable minerals from less valuable ones. To make the process more efficient, several methods have been developed to investigate how various factors affect particle floatability (recovery). Traditionally, this is done by measuring the hydrophobicity of the particles. However, floatability is a much broader concept that encompasses not only hydrophobicity but also other factors such as hydrodynamic conditions. In our research, we introduce a novel approach to quantify particle floatability from a mixture through dynamic bubble surface coverage experiments, considering hydrodynamic effects. Our focus is to understand how the different particles attach to a single bubble from a system containing two (or three) different particle types (chalcopyrite and/or pyrite + quartz). In particular, how one type of particle affects the recovery of another type.
Our objective is:
- To study the effect of pH and collector concentration on particle floatability.
- To establish a correlation between floatability and flotation recovery.
Experimental methods/techniques:
- Image acquisition and analysis
- Particle size analysis techniques such as laser diffraction and dynamic light scattering
Department: Transport processes at interfaces
Contact: Eftekhari, Milad, Öktem, Gülce
Requirements
- duration min. 6 month, workplace: HZDR
Online application
Please apply online: english / german
Dynamics of bubble-particle attachment in a model stirred cell (Id 404)
Master theses / Diploma theses / Compulsory internship
A process called flotation is widely used throughout the world to separate valuable minerals from non-valuable ones. Successful flotation relies on several sub-processes, such as promoting the attachment of certain sizes of particles to bubbles while preventing the attachment of others. Therefore, it is important to advance our knowledge about the particle attachment process, particularly, when different particle sizes are considered. Here we use our in-house setup to study:
- The effect of ultrafine particles on the attachment rate of fine particles.
- The effect of various parameters e.g., particles hydrophobicity on the packing density of the particles.
Experimental methods/techniques:
- Image analysis
- Particle size analysis techniques such as laser diffraction and dynamic light scattering
These experimental methods and the topic of particles at interfaces can prepare you for a variety of jobs after graduation, as these concepts are widely applicable in various fields such as mineral processing, recycling, pharmaceuticals, cosmetics, painting, and so on.
Department: Transport processes at interfaces
Contact: Eftekhari, Milad, Dr. Schwarzenberger, Karin
Requirements
- Study in process engineering, chemical engineering (or comparative field of study)
- Motivation, interest in this field of research, experimental experience
- Optimally: basic knowledge of particle measurement techniques
Conditions
duration min. 6 month, start: from now, workplace: HZDR
Online application
Please apply online: english / german
Experimental investigation of aerosol particle separation (Id 403)
Master theses / Diploma theses / Compulsory internship
As part of the CORAERO joint project (Airborne Transmission of SARS Coronavirus – From Fundamental Science to Efficient Air Cleaning Systems) funded by the Helmholtz Association, we are working on scientific issues relating to the formation of virus-laden aerosols, their thermodynamics and propagation in rooms, as well as strategies and technologies to prevent aerosol-borne infections.
The separation of aerosol particles in gas-liquid systems plays a central role in a variety of industrial and natural applications, among which stand out air purification and filtration systems as well as precipitation scavenging. The particle size significantly affects the separation rate. The diffusion of particles in the nanometer range is largely dominated by molecular diffusion. In this regime, predictive models accurately estimate the separation rates. Model inaccuracy increases, however, significantly when the particle size ranges from 0.1 μm to 2.5 μm. In this impaction-dominated regime, the complex interplay between the flow dynamics and the particle inertia makes it difficult to apply predictive tools.
A novel concept based on gas-liquid cyclone for particle separation is here to be conceived, tested and compared to a traditional wet filtering system. To this aim, we are looking for student interested in experimental multiphase flow investigations.
For more info please visit: https://www.coraero.de/
Department: Experimental Thermal Fluid Dynamics
Contact: Dr. Wiedemann, Philipp, Cavagnola, Marco Alejandro
Requirements
- Currently study chemical/mechanical/process engineering or natural sciences
- Good communication skills in German AND English
- Enjoy working in the lab and be able to work independently
Conditions
The duration of the work should ideally be 6 months. Remuneration is available.
Online application
Please apply online: english / german
Investigation of the flow following behavior of lagrangian sensor particles in aerated reactors (Id 398)
Master theses / Diploma theses / Compulsory internship
Data acquisition in large industrial vessels such as bio reactor, biogas fermenters or wastewater treatment plants is limited to local measurement points due to the limited access to the vessel and the non-transparent fluid. To optimize these kinds of plants the three-dimensional flow field and the spatial distribution of e.g. temperature and electrical conductivity inside the vessel needs to be known. This can be done by the autonomous flow following lagrangian sensor particles (LSP) developed at the HZDR. Equipped with a pressure sensor, an accelerometer, two gyroscopes and a magnetometer, the sensor particle can track the flow movement inside of the vessels. From this, the flow field can be reconstructed.
To achieve a good flow following behavior, the density of the LSP can be adjusted before they are released into the vessel. While this works well for non-aerated systems, the influence of aeration on the flow following capability is unknown. Another unknown is how the velocities of the rising bubbles and of the continuous phase relates to the velocity measured by the LSP.
Therefore, the aim of this master thesis is to investigate the influence of aeration on the LSPs theoretically and experimentally by tracking the LSP with a camera. This includes the following tasks:
- Literature research on flow following behavior of large particles in fluids
- Experiments in a bubble column (330 mm ID) with LSPs and camera
- Data evaluation to retrieve the fluid velocity, bubble rising velocity and LSP velocity
- Comparison and conclusions on the flow following capability of LSPs in aerated reactors and comparison to the non-aerated case.
Department: Efficient wastewater treatment
Contact: Buntkiel, Lukas, Marchini, Sara
Requirements
- Studies in the area of chemical or mechanical engineering or similar
- Basic chemical and fluid engineering knowledge
- Data analysis in Python
- Independent and structured way of working
Conditions
- Immediate start possible
- Duration according to the respective study regulations
Links:
Online application
Please apply online: english / german
Numerical investigation of particle mixing – internship or thesis (Id 396)
Master theses / Diploma theses / Compulsory internship / Volunteer internship
Fine-grained solid particles from various industrial sources, which would otherwise be discarded, should ideally be processed to valuable products or inert residues. Among others, a) shredder fines from electronics and end-of-life vehicles, and b) flue dusts from non-ferrous metallurgical processes are of timely interest. They contain valuable residuals, such as metals, that can be returned to the industrial cycle instead of being landfilled. This is one aim of the Helmholtz project FINEST in which this work is embedded.
The different finest powders need to be mixed and agglomerated for further processing. Our work in the project deals with the granular mixing. One aim is to describe particle flow based on the rheology of the bulk good while describing the mixing process among the particles using a transport equation.
The particle bulk flow in a mixing apparatus can be modelled by CFD, using e.g. FEM. The particle flow field is then coupled with the transport equation to describe the mixing process among the particles.
We are looking for someone with experience in CFD or other modelling to tackle the implementation of this model. Expertise in the numerical development of in-house multi phase flow solvers is available [Lecrivain, JCP, 2021].
Department: Particle dynamics
Contact: Baecke, Anna Magdalena, Dr. Lecrivain, Gregory
Requirements
- Student of e.g. Process Engineering, Chemical Engineering, Computational Engineering, Mechanical Engineering, …
- General interest in fluid mechanics and simulations
- Preliminary experience in CFD, ideally OpenFOAM
- Preliminary experience in code development (C++) optional
Conditions
- Immediate start possible
- Duration of internship or thesis according to study regulations
- Remuneration available, scholarship holders (e.g. ERASMUS+) welcome
Online application
Please apply online: english / german
Automatisierte Auswertung von 1D- und 2D-Ramanspektroskopischen Meßreihen (Id 393)
Bachelor theses / Master theses / Diploma theses
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.
Department: Nanocomposite Materials
Contact: Dr. Krause, Matthias
Requirements
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
Conditions
Die Arbeit ist in die umfangreichen Aktivitäten der Abteilung Nanoelektronik (FWIO) zu 2D-Werkstoffen eingebettet. Sie kann jederzeit aufgenommen werden.
Online application
Please apply online: english / german
Experimental investigation of Taylor bubble shape in narrow tubes with constrictions (Id 390)
Bachelor theses / Master theses / Diploma theses / Compulsory internship / Volunteer internship
The presence of geometrical singularities in pipes may significantly affect the behavior of two-phase flow and subsequently the liquid film thickness or bubble shape. Therefore, it is an important subject of investigation in particular when the application concerns industrial safety and design.
In this work, the shape of individual air Taylor bubble in vertical tubes with constrictions subjected to counter-current liquid is experimentally performed and the influence of the obstacle on the bubble shape is analyzed. The restrictions that the constrictions on narrow tubes imposes on the motion of the interface, and its effect on the bubble shape, will be addressed in terms of geometrical and flow parameters.
In this work, the student will experimentally investigate and record high quality images and gain knowledge about experimental work regarding two-phase flow, image acquisition with MATLAB and data organization. The results will lead to the development of a flow regime map in function of diameter and viscosity.
Institute: Institute of Fluid Dynamics
Contact: Maestri, Rhandrey
Requirements
General interest in fluid mechanics;
Preliminary experience in experimental work is desirable;
Good written and oral communication skills in either English or German.
Conditions
Immediate start;
Duration of the internship is anticipated to be 3 months but can be modified according to study regulations;
Remuneration according to HZDR internal regulations.
Online application
Please apply online: english / german
Master’s thesis “Analysis of existing incentive systems and development of a new incentive/bonus system to motivate transfer activities in a scientific institution” (Id 388)
Master theses / Student Assistant
The HZDR makes significant contributions to solving the major challenges facing society – with real, concrete and measurable benefits and impact. The HZDR is committed to excellence and a leading international position, not only in research and the operation of large research infrastructures, but also in transfer. Knowledge and technology transfer are directly part of the HZDR’s social mission and statutory purpose. The HZDR’s mission statement states: “By actively exploiting its research results, the HZDR makes a significant contribution to the future viability of the economy and society”.
With its Transfer Strategy 2025+, the HZDR has set itself the overarching goal of further increasing its success in the field of knowledge and technology transfer, while at the same time expanding the visibility of the HZDR.
Measures have been defined to implement the strategy, including the development of suitable incentive systems for scientific staff as well as management levels.
The aim of this work is to record the current incentive system and to work out the weaknesses, taking into account current literature and existing surveys at the HZDR. Based on these results, a new incentive system is to be developed with the involvement of stakeholders at the centre (surveys, workshops).
Department: Technology Transfer & Innovation
Contact: Pöpping, Uwe
Requirements
You are studying industrial engineering, economics or another degree (especially STEM) with a partial business qualification. You have significant practical experience in the relevant areas and have good MS Office skills. You work independently, in a structured manner, can quickly familiarise yourself with new tasks and are happy to contribute to a motivated team. You have a very good knowledge of English.
Conditions
We offer you exciting and challenging tasks, a collegial and international working environment, active support in the implementation of your tasks as well as scope for decision-making and responsibility. The place of work is Dresden-Rossendorf. Some of the tasks can be carried out at home by arrangement. The duration of the SHK activity (min. 5 h/week) should be at least one year, that of the Master’s thesis (full-time) should be at least 3 months.
Online application
Please apply online: english / german
Two phase flow in a mili-/micro-fluidic channel: rare-earth extraction/stripping with/ without magnetic field (student assistant 19 h/week for 3 months + extensions) (Id 386)
Student Assistant
Rare earth elements are group of 17 elements in periodic table. They have unique physicochemical properties which make them essential in many high-tech components, e.g. electric mobility, laser, catalyst etc. The separation of rare earths in industry is mainly done by liquid-liquid extraction, a technique of high environmental footprint. The separation is based on the marginal difference in their affinity against the extractant used. Hence, the separation factor, a parameter quantifying the “separability” of these elements, are small. Normally, hundreds of repeating stages has to take place in plants producing multiple single rare earth products.
We are actively researching a potentially more environmentally friendly alternative approach to improve the separation factor in solvent extraction of rare earths. One approach is to modulate their respective extraction kinetics. Rare-earth ions are affected due to their magnetic susceptibility in a stray field of a magnetic source. The Kelvin force that occurs, can selectively influence the extraction kinetics. Once the goal of establishing a functioning microfluidic flow system has been achieved, a magnetic field can be applied. Various experiments are carried out to separate rare earths in this way. This allows conclusions to be drawn about the reaction kinetics and a deeper understanding of the physical chemical processes can be obtained. For promising candidates there is subsequently the opportunity (Belegarbeit/ Diplomarbeit)) for further employment.
Department: Transport processes at interfaces
Requirements
1. Interest on applied optical experiment
2. Basic chemical and fluid engineering knowledge
3. can handle common lab chemicals
4. Work conscientiously and safely
5. Capable of communication and some basic data analysis skill
Conditions
1. Design and assembly the experimental setup of two two-phase-flow systems, one with a slug-flow and one with a parallel-flow of aqueous and organic solution (Fig 1).
2. Add and adjust pumping system and creation control program
3. UV – Vis Spectroscopy for different rare-earth concentrations
4. Experimental study with/ without applied magnetic field
Online application
Please apply online: english / german
Two phase flow in a mili-/micro-fluidic channel: rare-earth extraction/stripping with/ without magnetic field (student assistant 19 h/week for 3 months + extensions) (Id 385)
Student Assistant
Rare earth elements are group of 17 elements in periodic table. They have unique physicochemical properties which make them essential in many high-tech components, e.g. electric mobility, laser, catalyst etc. The separation of rare earths in industry is mainly done by liquid-liquid extraction, a technique of high environmental footprint. The separation is based on the marginal difference in their affinity against the extractant used. Hence, the separation factor, a parameter quantifying the “separability” of these elements, are small. Normally, hundreds of repeating stages has to take place in plants producing multiple single rare earth products.
We are actively researching a potentially more environmentally friendly alternative approach to improve the separation factor in solvent extraction of rare earths. One approach is to modulate their respective extraction kinetics. Rare-earth ions are affected due to their magnetic susceptibility in a stray field of a magnetic source. The Kelvin force that occurs, can selectively influence the extraction kinetics. Once the goal of establishing a functioning microfluidic flow system has been achieved, a magnetic field can be applied. Various experiments are carried out to separate rare earths in this way. This allows conclusions to be drawn about the reaction kinetics and a deeper understanding of the physical chemical processes can be obtained. For promising candidates there is subsequently the opportunity (Belegarbeit/ Diplomarbeit)) for further employment.
Department: Transport processes at interfaces
Contact: Bidmon, Alexander, Dr. Lei, Zhe
Requirements
1. Interest on applied optical experiment
2. Basic chemical and fluid engineering knowledge
3. can handle common lab chemicals
4. Work conscientiously and safely
5. Capable of communication and some basic data analysis skill
Conditions
1. Design and assembly the experimental setup of two two-phase-flow systems, one with a slug-flow and one with a parallel-flow of aqueous and organic solution (Fig 1).
2. Add and adjust pumping system and creation control program
3. UV – Vis Spectroscopy for different rare-earth concentrations
4. Experimental study with/ without applied magnetic field
Online application
Please apply online: english / german
Synthesis of innovative collectors for application in recovery of metals from industrial wastewaters (Id 384)
Bachelor theses / Master theses / Diploma theses / Compulsory internship
Ion flotation and solvent extraction are promising separation processes to separate and/or remove low concentrated metals from process waters. The demand for developing special collectors (ion flotation reagent)/extractants for enhanced separation efficiency of metals using these processes is increasing due to increased demand for the metals. Further to make these processes sustainable, these special molecules need to be highly selective, efficient and ecofriendly. Strong metal binding ability is the main requisite for such novel molecules and further depending on their application, they need to behave as flotation or solvent extraction reagent. However, synthesizing novel collectors having both abilities is a challenging task. Thus, the main aim is to modify the molecules with already known metal specificity, to introduce the hydrophobicity required for the ion flotation or solvent extraction process.
This student work aims to modify the molecules by adding new functionalities and synthesizing them for improved metal complexation and process application. Additionally, their characterization as possible reagents in either flotation or solvent extraction processes will be investigated. The results will help in fundamental understanding of modified molecules in terms of their interaction with metals as well as form the basis for the development of a sustainable metal recovery process. This interdisciplinary project offers a unique integration of approaches, competences and resources in biotechnology, chemistry and process and environmental engineering and involves different departments at HIF.
Tasks:
- Selection of hydrophobic group
- Modification, synthesis and purification of novel molecules
- Characterization of developed molecules, Ion flotation or solvent extraction tests
Department: Hydrometallurgy
Contact: Dr. Chakankar, Mital Vivek, Dr. Kelly, Norman, Dr. Patil, Ajay Bhagwan
Requirements
- Field of study: Chemistry, Chemical Engineering
- Experience in organic chemistry, knowledge of the techniques to synthesize compounds and to characterize them; experience in coordination chemistry, biochemistry and/or technical chemistry is advantageous
- Good communication skills in German and English, spoken and written
- Ability to work independently and systematically
Conditions
Working in a multi-disciplinary and international team, with world class research environment at HZDR and HIF.
Can get cross functional working experience and exposure to organic synthesis, modified biomolecules, solution and extractive hydrometallurgy, process biotechnology, chemical and environmental engineering
- Working place HZDR: Location Dresden or Freiberg (HIF)
- Start date: Either an immediate start or a start in 2023 is possible
- Duration: 6 month
- Remuneration according to HZDR internal regulation
Online application
Please apply online: english / german
Internship on experimental investigation of aerosol propagation (Id 381)
Student practical training / Compulsory internship / Volunteer internship
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.
Department: Experimental Thermal Fluid Dynamics
Requirements
- Student of natural sciences or engineering
- Willingness to conduct experimental work
Conditions
Duration:
4-6 months
Remuneration:
According to HDZR guidelines
Online application
Please apply online: english / german
Numerical simulation of particles in rising gas bubbles (Id 356)
Student practical training / Master theses / Student Assistant / Compulsory internship / Volunteer internship
The separation of aerosol particles by a moving gas-liquid fluidic interface is central to a wide variety of industrial and natural applications, among which stand out air purification systems and precipitation scavenging. The particle size significantly affects the separation rate. The diffusion of particles in the nanometer range is largely dominated by molecular diffusion. In this regime, predictive models accurately estimate the separation rates. Model inaccuracy increases, however, significantly when the particle size ranges from 0.1 μm to 2.5 μm. In this impaction-dominated regime, the complex interplay between the flow dynamics on both sides of the fluidic interface and the particle inertia makes it difficult to develop suitable models.
In this work, the student will numerically investigate whether enforcing bubble deformation into a non-spherical shape leads to a higher deposition rate, hereby making the particle separation process more efficient. The results will lead to the development of an improved and reliable separation model accounting for the deformation of the fluidic interface and the associated flow changes.
Department: Experimental Thermal Fluid Dynamics
Contact: Maestri, Rhandrey
Requirements
- General interest in fluid mechanics
- Preliminary experience in code development (C++) is desirable
- Good written and oral communication skills in either English or German
Conditions
- Either an immediate start or a start in 2024 is possible
- Duration of the internship is anticipated to be 6 months but can be modified according to study regulations
- Remuneration according to HZDR internal regulations
Online application
Please apply online: english / german
Self-organized nanopattern formation on crystalline surfaces of III-V semiconductors (Id 341)
Master theses / Diploma theses
Various metals, semiconductors, and oxides form regular nanoscale surface patterns in a complex process of self-assembly under low energy ion irradiation. Depending on both instrinsic factors of the material and externally controllable irradiation conditions, nanopatterns of very different morphologies will form, making ion-induced pattern formation a highly complex process. We study this process with regards to the material properties of various elemental and compound semiconductors, their crystal structure and surface orientation, the influence of irradiation parameters, and the patterning kinetics. Thereby, we expect to obtain new insights into the complex process of ion-induced nanopattern formation in technologically relevant materials.
We offer several projects, focussing each on a specific semiconductor material and its behavior under ion irradiation. These projects comprise the preparation of nanopatterned surfaces by low energy ion irradiation, imaging these surfaces surfaces by atomic force microscopy and electron microscopy, the quantitative analysis of these data, as well as simulating the patterning process based on continuum equations or kinetic MonteCarlo models.
The experimental work on these projects should result a diploma or M.Sc. thesis in physics, material science, or a related field of study. The provide an introduction to research at a large scale facility (Ion Beam Center IBC) and opportunities for networking with HZDR specialists on nanoscale surface modification and characterization.
Department: Ion Beam Center
Contact: Dr. Erb, Denise
Requirements
— completed B.Sc. studies or Vordiplom in experimental physics, materials science, or related subject
— good command of German and/or English
— ability to work independently and systematically
Conditions
— place of work: HZDR, location Rossendorf
— project duration: 12 months, flexible starting time
Links:
Online application
Please apply online: english / german
Organisch-chemische Synthese neuer Radioliganden für die Diagnostik und Therapie von Krebserkrankungen (Id 295)
Student practical training / Bachelor theses / Master theses / Diploma theses
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 Abschlussarbeit (Bachelor/Master/Diplom) sollen organische Wirkstoffmoleküle synthetisiert und für eine anschließende radiochemische Markierung modifiziert werden. Die neuen Radioliganden werden dann biologisch in vitro und in vivo untersucht.
Department: Translational TME Ligands
Contact: Dr. Stadlbauer, Sven, Sachse, Frederik
Requirements
- 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
Conditions
- Beginn nach Absprache jederzeit möglich
- Praktikumsdauer mindestens 8 Wochen, mit möglichst täglicher Anwesenheit (keine wiss. Hilfskräfte)
- Vergütung erfolgt nach HDZR-Richtlinien
Online application
Please apply online: english / german
Materials for new solar power plants (Id 241)
Bachelor theses / Master theses / Diploma theses
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.
Department: Nanocomposite Materials
Contact: Dr. Krause, Matthias
Requirements
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)
Conditions
Internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung
Online application
Please apply online: english / german