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.


3D characterization of slags and ores using computed tomography (Id 391)

Bachelor theses / Master theses / Diploma theses / Student Assistant / Compulsory internship

Computed tomography is a prevalent technique used for the 3D characterization of ores at the particle level. However, the presence of image artefacts has hindered the establishment of a standardized workflow for automated 3D mineralogical quantification. The primary objective of this project is to develop and standardize such a workflow for the 3D characterization of particulate materials. The results will be tested and validated using ores and slags. As a part of this project, we are offering a student assistant position to contribute to the experimental and/or data processing developments of the workflow. The work can be projected into a BSc or MSc thesis/internship.
Department: Analytics
Responsibilities

  • Sample preparation and scanning of samples using X-ray computed tomography.
  • Processing 3D images.
  • Quantification of 3D particle properties
  • Assistance in other laboratory tasks to characterize samples.

Department: X-ray and bulk analytics

Contact: Dr. da Assuncao Godinho, Jose RicardoGupta, Shuvam

Requirements

  • Enrolled in STEM courses. E.g. Materials/Earth/Computer science/Engineering etc.
  • Basic understanding/willingness to learn Python.
  • Good written and oral communication skills in English.

Conditions

  • Working place HZDR: Freiberg (HIF)
  • Start date: As soon as possible
  • Duration: flexible 19 h/week, initially for 6 months
  • Remuneration according to HZDR internal regulation

Links:

Online application

Please apply online: english / german

Druckversion


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

Druckversion


Student assistant wanted in the area of technology transfer and innovation (Id 389)

Student Assistant

Your tasks:

  • Participation in the screening of potential research results
  • Internet and database research for market, competition and patent analyses
  • Preparation of exploitation and business plans for spin-offs
  • Preparation of cost calculations and financial plans
  • Preparation of technology exposés
  • Preparation of presentations
  • Database maintenance, reporting, evaluation of data on transfer indicators
  • After individual consultation, independent processing of various projects (e.g. conception and support of reporting system & benchmarking etc.)

Department: Technology Transfer & Innovation

Contact: Pöpping, UweDr. Wolf, Björn

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.

Online application

Please apply online: english / german

Druckversion


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

Druckversion


Experimental investigation of aerosol particle separation (Id 387)

Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship

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.

Department: Experimental Thermal Fluid Dynamics

Contact: Cavagnola, Marco Alejandro

Requirements

You currently study chemical Engineering or natural sciences, you have good communication skills in German or English. You also enjoy working in the lab and your are 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

Druckversion


Synthesis of innovative collectors for application in recovery of metals from industrial wastewaters (Id 384)

Master theses / Diploma theses

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 VivekDr. Kelly, NormanDr. 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

Druckversion


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:

Available

Online application

Please apply online: english / german

Druckversion


Optical measurements of refractive index of rare earth solutions (5 – 10 h/week for 3 Months, extend possible) (Id 380)

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 by modulating their respective extraction kinetics. Addressing the magnetic susceptibility of rare-earth ions inside a stray field from magnetic source, the Kelvin force acting on the rare-earth can tune the extraction kinetics selectively. To experimentally quantifying the enhancement, detailed mapping of refractive index of rare-earth solution is mandatory which further facilitates an in-situ space- and time- resolved monitoring of the extraction process of rare-earth mixtures. In order to understand the chemical-physical fundamentals of the process, detailed investigations are necessary.
Interferometry enables non-invasive real-time measurement of substance concentrations. This is an attempt to determine the reaction law for rare earth elements such as samarium. For this purpose, the refractive index of the substance is measured, which is, among other things, temperature-dependent. Consequently, an investigation of factor marks a starting phase where promising candidates will be offered opportunity (Belegarbeit/ Diplomarbeit) for further laser based optical experimentation and algorithm developments.

Department: Transport processes at interfaces

Contact: Bidmon, AlexanderDr. Lei, Zhe

Requirements

1. Interest on applied optical experiment
2. Work conscientiously and safely
3. Capable of communication and some basic data analysis skill

Conditions

1. Characterization of optical properties of rare earth elements as a basis for interferometry experiments
2. Evaluation and assessment of self-measured values for better process understanding

Online application

Please apply online: english / german

Druckversion


Experimental investigation of the overflowing foam in a laboratory-scale froth flotation cell by optical measurements (Id 377)

Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship

Foto: Foam height measurement ©Copyright: Dr. Tobias LappanThe global energy transition requires increasing quantities of raw materials. Critical metals, including copper, lithium, cobalt, nickel, zirconium and platinum, are used, for example, in photovoltaic and wind power plants to exploit renewable energies, in batteries for electromobility, in electrolysers and fuel cells as hydrogen technologies. Rare earth elements, such as neodymium and samarium, are irreplaceable for permanent magnets in electrical generators and motors. The extraction of raw materials from metal ores poses a great challenge to the mineral industry. An important process step in the effective processing of ore minerals, and equally in material recycling in terms of the circular economy, is froth flotation.
In this process, finely ground solid particles are suspended in an aqueous liquid, and gas bubbles are added. Particles with hydrophobic surfaces adhere to the rising bubbles, which then form a particle-laden froth layer on top of the liquid. The particles can be recovered by skimming off the froth. Surfactants and other flotation reagents enable the desired particles to adhere, favour the sinking of the unwanted particles, or serve to stabilise the froth. The deformation and flow behaviour of the froth influences the transport and selective separation of desired and undesired particles due to their surface wettability. However, foam and froth flows are not well understood because typically only the free surface is accessible for optical measurements. Suitable techniques for flow measurement within the foam or froth volume, i.e. below the non-transparent surface, are still lacking and only under development.
This student work aims to experimentally investigate of the overflowing foam in a laboratory-scale froth flotation cell, focussing on the foam height in combination with the foam bubble size and the flow velocity at the free surface. For this purpose, optical measurement techniques will be used, as they are already partly in use for monitoring the froth phase in industrial flotation cells. On the one hand, the results will serve for a better understanding of the overflowing foam, and on the other hand, they represent an important preliminary work for the further development and adaptation of optical measurement techniques for flotation cells.
The following subtasks are mainly to be worked on:

  • setup and test of a measurement system consisting of a Raspberry Pi, a Lidar sensor for the point measurement of the foam height, and a camera for the optical detection of the foam bubble size and flow velocity at the free surface
  • measurement of the overflowing foam in a laboratory-scale flotation cell, depending of the surfactant concentration and the gas volume flow generating the foam
  • analysis of the measurement data, including machine learning if applicable

Department: Transport processes at interfaces

Contact: Dr. Lappan, TobiasMarquardt, Tine

Requirements

  • Field of study: Chemical Engineering, Process Engineering, Fluid Mechanics, or similar focus in Chemistry or Physics
  • Experience with laboratory work, optical measurement techniques or measurement data analysis is beneficial
  • 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

Conditions

  • Working in a multi-disciplinary and international team
  • Place of work: HZDR or TU Dresden
  • Start: from June/July 2023
  • Duration: min. 3 months
  • Remuneration according to HZDR internal regulations

Online application

Please apply online: english / german

Druckversion


Studentische Hilfskraft (w/m/d) in der Verwaltung und im Reisekostenmanagement (Id 366)

Student Assistant

Mit Spitzenforschung in den Bereichen ENERGIE, GESUNDHEIT und MATERIE lösen wir am Helmholtz-Zentrum Dresden-Rossendorf (HZDR) einige der drängenden gesellschaftlichen Herausforderungen unserer Zeit. Das Görlitzer Center for Advanced Systems Understanding (CASUS) ist ein weltweit einzigartiges Zentrum für datenintensive Forschung im Bereich digitaler Systeme. Die deutsch-polnische Einrichtung wurde 2019 gegründet und betreibt interdisziplinäre Systemforschung in unterschiedlichen Bereichen wie Erdsystemforschung, Systembiologie und Materialforschung.

Das HZDR Center for Advanced Systems Understanding (CASUS) sucht ab sofort Studierende, die das Feld des Reisekostenmanagement und Verwaltung in einem öffentlichen Sektor kennenlernen und erste Erfahrungen in einem internationalen Umfeld sammeln möchten. Als SHK bist Du zuständig für die Organisation von Reisen und Unterstützung bei deren Durchführung und Abrechnung, sowie Unterstützung der administrativen Verwaltung in Görlitz bei unterschiedlichen Angelegenheiten, Aufgaben und Projekten.

Wir bieten:

■ Einen flexiblen Job mit guter Bezahlung, der sich auch noch gut im Lebenslauf macht
■ Freude bei der Arbeit in einem internationalen Team
■ Erfahrungen:
– bei der Vermittlung von Wissen sowie Softskills
– in der Arbeit mit Verwaltungssysteme wie SAP
– in der Arbeit mit Reisekostenabrechnungssystemen
– organisatorische Fähigkeiten, die bei Prüfungen, Bewerbungen und dem späteren Job helfen
■ Auf Wunsch eine längerfristige Perspektive mit einem Aufgabenspektrum, das mit der Zeit immer vielfältiger wird und zunehmend auch eigenverantwortliche Projekte enthält

Institute: CASUS

Contact: Mazur, Weronikavon Haymerle, Philipp

Requirements

■ Freude am Organisieren und an der Kommunikation im Team, mit Wissenschaftlern, Dienstleistern sowie mit unterschiedlichen Zielgruppen
■ Deutsch- und Englischkenntnisse
■ 19 Stunden pro Woche die Möglichkeit zum Arbeiten (flexible, aber anteilige Verteilung)

Conditions

Der Arbeitsbeginn soll nach Abstimmung relativ kurzfristig erfolgen.

Weiterführende Informationen können jederzeit gern erfragt werden bei:

Weronika Mazur | CASUS International Office
Philipp von Haymerle | CASUS Project Manager

Tel.: +49 3581 37523 23 | E-Mail: w.mazur@hzdr.de;
+49 3581 37523 21 | E-Mail p.haymerle@hzdr.de

CASUS – Center for Advanced Systems Understanding am HZDR
Untermarkt 20 | D-02826 Görlitz
www.casus.science

Online application

Please apply online: english / german

Druckversion


Numerical simulation of particles in rising gas bubbles (Id 356)

Student practical training

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, RhandreyDr. Lecrivain, Gregory

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 2022 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

Druckversion


Calculation of multi-phase flow using the GENTOP model with FLUENT (Id 346)

Master theses / Diploma theses / Compulsory internship

Foto: Fig. 1: Boiling pipe flow (left: disperse gas volume fraction, right: continuous gas volume fraction) from Setoodeh et al., Applied Thermal Engineering 204 (2022) 117962 ©Copyright: Dr. Thomas HöhneAs a member of the Helmholtz Association of German Research Centers, the HZDR employs about 1,400 people. The Center’s focus is on interdisciplinary research in the areas energy, health and matter. The Institute of Fluid Dynamics is conducting basic and applied research in the fields of thermo-fluid dynamics and magnetohydrodynamics in order to improve the sustainability, the energy efficiency and the safety of industrial processes.

Multiphase flows are important part of many industrial applications, whereas modelling of them is a challenging and complex task. For flow situations with higher void fractions, HZDR developed a new generalized concept for the CFD-simulations including flow regime transitions. The GENTOP (Generalized Two-Phase Flow) approach is able to simulate co-existing large-scaled (continuous) and small-scaled (polydispersed) structures (Fig. 1). Previous results were performed with the CFD code CFX and compared against DEBORA validation data.

The goal of the thesis would be to apply and improving the existing state of the simulations in the Fluent GENTOP framework.

We offer an interesting task dealing with complex physical phenomena, work in an international team using state-of-the-art calculation and programming methods.

We are looking for a motivated student (f/m/d) (master thesis) able to perform CFD simulations, understand and program code to generalize/parametrize CFD simulations, work with experimental data sets, document and present the work in an appropriate manner. Useful but not required is a knowledge of the following software tools: CFD codes CFX and Fluent, Python, GIT.

The task is supervised by Framatome and HZDR.

FRAMATOME is a designer and supplier of nuclear steam supply system and nuclear equipment, services and fuel for high levels of safety and performance. Framatome is a major international player in the nuclear energy market recognized for its innovative solutions and value-added technologies for designing, building, maintaining, and advancing the global nuclear fleet. The company designs, manufactures, and installs components, fuel and instrumentation and control systems for nuclear power plants and offers a full range of reactor services. With 14,000 employees worldwide, every day Framatome’s expertise helps its customers improve the safety and performance of their nuclear plants and achieve their economic and societal goals.

Department: Computational Fluid Dynamics

Contact: Dr. Höhne, ThomasDr. Lucas, Dirk

Requirements

  • Studies in Engineering, Computer Science or comparable
  • Interest in numerical work
  • Good communication skills in both written and spoken English
  • Useful but not required is a knowledge of the following software tools: CFD codes CFX and Fluent, Python, GIT.

Conditions

  • A vibrant research community in an open, diverse, and international work environment.
  • Scientific excellence and extensive professional networking opportunities.
  • Compensation as student researcher (working hours to be determined).
  • Working place will be Dresden and/or Erlangen Germany.

Online application

Please apply online: english / german

Druckversion


Self-organized nanopattern formation on crystalline SiGe surfaces (Id 342)

Master theses / Diploma theses

Foto: AFM images of ion-induced surface patternings ©Copyright: Dr. Denise ErbVarious metals, semiconductors, and oxides form regular nanoscale surface patterns in a complex process of self-assembly under low energy ion irradiation. While the elemental semiconductors Si and Ge have been extensively studied in this respect, there is no such investigation for alloys of Si and Ge. We want to explore which nanoscale pattern morphologies can emerge on SiGe surfaces and how they can be modified via the conditions of ion irradiation. We expect to obtain new insights into the complex process of ion-induced nanopattern formation in technologically relevant materials.
This work comprises 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 project provides an introduction to research at a large scale facility (Ion Beam Center IBC) and opportunities for networking with HZDR specialists (f/m/d) 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

Druckversion


Self-organized nanopattern formation on crystalline surfaces of III-V semiconductors (Id 341)

Master theses / Diploma theses

Foto: AFM images of ion-induced surface patternings ©Copyright: Dr. Denise ErbVarious metals, semiconductors, and oxides form regular nanoscale surface patterns in a complex process of self-assembly under low energy ion irradiation. Depending on the experimental conditions nanopatterns of very different morphologies will form. They can be categorized into either the erosive or diffusive regime – depending on the dominant mass transport processes on the surface. For compound semiconductors the erosive regime has rarely been investigated so far. We want to find out under which conditions the expected nanopattern formation in the diffusive regime takes place. We expect to obtain new insights into the complex process of ion-induced nanopattern formation in technologically relevant materials.
This work comprises 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 project provides an introduction to research at a large scale facility (Ion Beam Center IBC) and opportunities for networking with HZDR specialists (f/m/d) 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

Druckversion


Self-organized nanopattern formation on crystalline GaAs and InAs surfaces (Id 340)

Master theses / Diploma theses

Foto: AFM images of ion-induced surface patternings ©Copyright: Dr. Denise ErbVarious metals, semiconductors, and oxides form regular nanoscale surface patterns in a complex process of self-assembly under low energy ion irradiation. Studies of the elemental semiconductors Si and Ge have shown that the symmetry of their crystalline surface strongly influences the morphology of those nanopatterns. However, only one particular surface orientation has been studied analogously for the compound semiconductors GaAs and InAs. While for these materials, the nanopattern morphology is mainly attributed to their compound character, a significant additional influence of the surface crystal structure is expected. We want to demonstrate this by investigation the ion-induced pattern formation on crystalline GaAs and InAs with various surface orientations. The resulting surface patterns may find application in the bottom-up fabrication of complex nanostructured systems.
This work comprises the preparation of nanopatterned surfaces by low energy ion irradiation, imaging these surfaces by atomic force microscopy and scanning tunnelling microscopy, the quantitative analysis of these data, as well as simulations of the patterning process based on continuum equations or kinetic MonteCarlo models.
The project provides an introduction to research at a large scale facility (Ion Beam Center IBC) and opportunities for networking with HZDR specialists (f/m/d) 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

Druckversion


Optical properties of Ag nanocube ensembles (Id 339)

Master theses / Diploma theses

Ensembles of nanoscale metallic objects such as Ag nanocubes exhibit particular optical properties, which can be influenced by size, shape and spatial arrangement of these objects. Ion beam based techniques enable the preparation of nanopatterned surfaces, on which Ag nanocubes can be arranged in a regular fashion, as well as the modification of the nanocube shape by ion erosion. Thus the effects of changes in arrangement and shape on the optical properties of the ensemble can be studied.
This work comprises the preparation of nanopatterned surfaces by low energy ion irradiation, the arrangement of Ag nanocubes on such surfaces and their deformation by ion beam erosion, the imaging of theses sample systems by atomic force microscopy and scanning electron microscopy, the measurement of optical properties by cathodoluminescence and ellipsometry, and the quantitative analysis of the obtained data.
The project provides an introduction to research at a large scale facility (IBC) and opportunities for networking with HZDR specialists (f/m/d) 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

Druckversion


Motion tracking of autonomous sensor particles in industrial vessels (Id 335)

Master theses / Diploma theses / Compulsory internship

Foto: AutoSens_StirredReactor ©Copyright: fwdf (Mailgruppe)Data acquisition in large industrial vessels such as biogas fermenters or wastewater treatment plants is limited to local measurement points due to limited access to the vessel and the non-transparency of the fluid. To optimize these kinds of plants, the three-dimensional flow field and the spatial distribution of fluid properties such as temperature and electrical conductivity inside the vessel must be known. This can be achieved by the autonomous flow-following sensor particles developed by the HZDR. Equipped with a pressure sensor, an accelerometer, two gyroscopes and a magnetometer, the sensor particle can track the movement inside the vessels and derive the flow field from that. Additionally, the sensor particle gets position information by an ultra-wide-band based localization module (like GPS) as soon as it is on the fluid surface. The motion of the sensor particle is currently tracked with an error-state Kalman filter and yields a reliable tracking of the velocity and position, respectively. However, the tracking time is limited by the propagation of uncertainties of the inertial sensors through the filter. The objective of this master thesis is to extend this tracking time by the use of more advanced tracking algorithms like particle filter or other types of Kalman filters. This includes the following tasks:

  • Literature review of advanced filters for motion tracking
  • Theoretical comparison and implementing the most promising algorithm in Python
  • Verification and performance analysis based on experimental data

Department: Experimental Thermal Fluid Dynamics

Contact: Buntkiel, LukasDr. Reinecke, Sebastian

Requirements

  • Studies in the area of electrical, mechatronic, mechanical engineering or similar
  • Basics of measurement uncertainty, digital signal processing
  • Data analysis in Python
  • Independent and structured way of working

Conditions

  • Start possible at any time
  • Duration according to the respective study regulations

Links:

Online application

Please apply online: english / german

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Experimental investigation of influence of interfacial viscoelasticity on the dripping to jetting transition (Id 333)

School practical training / Student practical training / Bachelor theses / Master theses / Compulsory internship

Foto: Capillary with jetting liquid-liquid interface ©Copyright: Milad EftekhariLiquid jets are unstable and eventually form droplets to minimize the surface energy with the surrounding fluid. The transition from dripping to jetting and dynamics of the droplet pinch-off have been studied extensively for various systems, from pure Newtonian fluids to complex non-Newtonian liquids. The jetting process has received significant attention as it is a critical step in various three-dimensional (3D) printing techniques such as dropwise additive manufacturing and the direct ink writing method. In most of the applications surface active materials such as surfactants, nanoparticles, and polymers exist in the systems. The presence of surface-active materials reduces the liquid-fluid surface energies and in some cases generates a viscoelastic layer at the interface.
In this research, we aim to study the influence of interfacial viscoelasticity on the dripping to jetting transition. The study is conducted by the injection of an aqueous phase (nanoparticle dispersions) into an oil phase that contains surfactants over a wide range of flow rates. We tune the magnitude of interfacial viscoelasticity by changing the concentration of surfactants and nanoparticles.
Research question:
Does the dripping to jetting transition (critical flow rate) linearly increase by increasing the interfacial viscoelasticity?

Experiments:

1. Measurements of interfacial tension and surface elasticity for a range of particle and surfactant concentration using Profile analysis tensiometry, and Langmuir trough.
2. Dripping to jetting experiments for the selected systems using high-speed cameras and in-house setups.

Department: Transport processes at interfaces

Contact: Eftekhari, MiladDr. Schwarzenberger, Karin

Requirements

  • Field of study: chemical engineering, process engineering, fluid mechanics, or similar focus in chemistry or physics
  • Experience with laboratory work and imaging measurement techniques is beneficial

Conditions

  • Working in an international team
  • Duration: at least 6 months
  • Location: Dresden-Rossendorf

Online application

Please apply online: english / german

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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, SvenSachse, 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

Links:

Online application

Please apply online: english / german

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Entwicklung von Radiotracern zur Bildgebung von Tumorerkrankungen (Id 283)

Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship / Volunteer internship

Die gezielte Behandlung von Tumorerkrankungen erlangt zunehmend an Bedeutung. Die eng mit der radiopharmazeutischen Forschung verknüpfte Nuklearmedizin ist auf die Anwendung radiomarkierter Verbindungen (Radiopharmaka) für die Tumordiagnostik und -therapie spezialisiert. Dabei wird ein bestimmtes Radionuklid entweder direkt am Molekül oder stabil in einem Komplexbildner gebunden und an ein biologisch aktives Molekül geknüpft (Peptid, Antikörper…). Das Radiopharmakon bindet dann spezifisch an bestimmten Zellen (z. B. Knochenzellen, Tumorzellen…). Während zur diagnostischen Bildgebung Gamma- und Positronenemitter eingesetzt werden, kommen für therapeutische Anwendungen ausschließlich Betaemitter und Alphaemitter zum Einsatz. Für den Alphaemitter Actinium-225 steht, sofern der Chelator macropa verwendet wird, gegenwärtig kein geeignetes diagnostisches Radionuklid zur Verfügung.

In diesem Forschungsprojekt sollen Konjugate hergestellt werden, welche mit einem bildgebenden Radionuklid (Fluor-18, Iod-123, Lanthan-133) radiomarkiert werden können. Die Konjugate sollen sich gleichermaßen für die stabile Bindung von Actinium-225 eignen. Nach erfolgreicher Synthese und Charakterisierung von definierten Zielverbindungen sollen diese radiomarkiert, und die Stabilität der radiomarkierten Substanzen im biologischen System beurteilt werden. Die vielversprechendsten Konjugate sollen anschließend auf zellulärer Ebene und schlussendlich präklinisch in vivo evaluiert werden.

Department: Radionuclide Theragnostics

Contact: Dr. Reissig, Falco

Requirements

  • Studium der Chemie oder eines artverwandten Studiengangs
  • Erfahrungen im Bereich der Synthesechemie und Analytik
  • Interesse an der wissenschaftlichen Arbeit in einem interdisziplinären Team
  • Bereitschaft zum Umgang mit Radioaktivität
  • Gute Kommunikationsfähigkeiten in Wort und Schrift (deutsch & englisch)

Conditions

  • Beginn ist nach Absprache ab sofort möglich
  • Praktikumsdauer mindestens 8 Wochen
  • Vergütung nach internen HZDR-Regelungen

Online application

Please apply online: english / german

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Materialien für Solarkraftwerke (Id 241)

Bachelor theses / Master theses / Diploma theses

Foto: solarthermisches Turmkraftwerk ©Copyright: @AbengoaTurmkraftwerke stellen die neueste Generation von Anlagen zur solarthermischen Elektroenergieerzeugung dar. Extrem konzentriertes Sonnenlicht wird dabei auf einen zentralen Absorber gerichtet, der die Wärme auf eine Wärmeträgerflüssigkeit überträgt (s. Foto). Zur Erhöhung des Wirkungsgrades von Turmkraftwerken soll die Arbeitstemperatur von derzeit maximal 550°C deutlich erhöht werden. Dafür sollen werkstoffwissenschaftliche Lösungen weiter verfolgt werden, die im Rahmen eines EU-RISE-Projektes entwickelt wurden.

Als Themen für Graduierungsarbeit werden

i) die Optimierung von optischen und elektrischen Schichteigenschaften
ii) die Verbesserung der Schichthaftung auf Hochleistungslegierungen und
iii) die Komplettierung eines neuen Schichtsystems angeboten.

Zur Charakterisierung der untersuchten Materialien stehen modernste in situ und ex situ Analysemethoden zur Verfügung.

Department: Nanocomposite Materials

Contact: Dr. Krause, Matthias

Requirements

1. Studium der Werkstoffwissenschaften, Physik oder Chemie mit überdurchschnittlichen Leistungen (Notendurchschnitt ≤ 2.0)
2. Interesse und Freude an experimenteller wissenschaftlicher Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Fachkundige Englischsprachkenntnisse

Conditions

internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung

Online application

Please apply online: english / german

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