PhD scholarship in Modelling of Vascular Flows in Plant Leaves

Monday 09 Sep 19

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A 3-year PhD scholarship, starting January 1, 2020, is available in the field of vascular fluid dynamics in plant leaves supervised by Prof. Tomas Bohr, in the section Biophysics and Fluids at the Department of Physics.

Description of the scientific environment and background
We study the fundamental physics of fluids both in living systems (plants and planktonic organisms) and in non-living macroscopic flows with free surfaces (e.g., hydraulic jumps and rotating flows). In plants, we have focused on the vascular transport in trees, in particular on the combined water -and sugar transport, which is the basis for survival and growth of the organism. Such flows are very interesting and unusual, since the upward water transport in the xylem occurs under negative pressure, whereas the sugar transport in the phloem (originating in the leaves) is under positive pressure and driven by osmosis. We have recently described the basic mechanisms for such flows in the review Sap flow and sugar transport in plants, Reviews of Modern Physics 88, 035007 (2016) (pdf). The supervisor has a strong collaboration with the group of Alexander Schulz, Department of Plant and Environmental Sciences (PLEN), Faculty of Science at University of Copenhagen (UCPH) specializing on advanced microscopic methods such as confocal live microscopy, super resolution -and electron microscopy in plant leaves.

Project description
The project is based on the research project Multimodal imaging and modelling of vascular flows in leaves, granted by the Independent Research Fund Denmark (Natural Sciences), supporting the collaboration between DTU and UCPH with one PhD fellow each. The successful DTU candidate will study the balance of water movement between evaporation, photosynthesis and osmotic phloem uptake to assess the sugar export out of the leaves. This balance is crucial in plants, since water is a limiting resource; but how this balance is regulated under changing environmental conditions is not understood. Key elements of the regulation are hidden in the leaves, and the modelling will be done in close collaboration with the experimental group of Alexander Schulz at UCPH using fluorescence and electron microscopy and the group of Henning Friis Poulsen at DTU Physics doing X-ray tomography. Our joint goal is to understand the mechanism and efficiency of the combined vascular flow, eventually exporting sugars out of the leaves, starting with the simplest vascular architecture: that of pine needles. The type of modelling currently used can be seen in two recent papers: Diffusion and bulk flow in phloem loading: A theoretical analysis of the polymer trap mechanism for sugar transport in plants, Physical Review E90, 042704 (2014) (pdf) and Sugar export limits size of conifer needles, Physical Review E 95, 042402 (2017) (pdf).

Responsibilities and tasks
The position is available for a 3-year period and your key tasks as a PhD student at DTU are to:Manage and carry through your research project:

  • Manage and carry through your research project
  • Take relevant PhD courses (30 ECTS)
  • Publish in international peer reviewed journals and write your PhD thesis
  • Participate in conferences
  • Stay at an external research institution for a few months, preferably abroad
  • Teach and disseminate your research
Candidates should have a two-year master's degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master's degree. 
  • Expertise and/or strong interest in fluid dynamics and biology
  • Professional qualifications relevant to the PhD programme
  • Previous publications
  • English language skills
Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see the DTU PhD Guide

We offer
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed upon with the relevant union. The period of employment is 3 years.

You can read more about career paths at DTU here

Further information
Further information may be obtained from Professor Tomas Bohr,, tel.: +45 4525 3310. 

You can read more about DTU Physics at

Please submit your online application no later than 25 October 2019 (23:59 local time). Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link "Apply online", fill out the online application form, and attach all your materials in English in one PDF file. The file must include: 
  • A letter motivating the application (cover letter)
  • Curriculum vitae
  • Grade transcripts and BSc/MSc diploma
  • Excel sheet with translation of grades to the Danish grading system (see guidelines and Excel spreadsheet here)
Candidates may apply prior to obtaining their master's degree but cannot begin before having received it.

Applications and enclosures received after the deadline will not be considered.

All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.

DTU is a technical university providing internationally leading research, education, innovation and scientific advice. Our staff of 6,000 advance science and technology to create innovative solutions that meet the demands of society, and our 11,200 students are being educated to address the technological challenges of the future. DTU is an independent university collaborating globally with business, industry, government and public agencies.