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Open positions in XIC
대학원 신입생 모집 안내
엑스선 영상 연구단 홈페이지 방문을 환영합니다.
우리 연구실에서는 기능 엑스선 영상을 이용한 Soft matter dynamics 및 Bio-medical imaging 분야와, organic nanowire 기반 삼차원 optoelectronics/photonics 분야에 대한 연구를 함께할 대학원생을 모집합니다.
관심 있는 학생들은 언제든지 연락 주시기 바랍니다.
  
Open positions for graduate students, undegraduate students, & post-doc
Welcome to visit X-ray Imaging Center (XIC) homepage
Our current research projects include studying soft matter dynamics and bio-medical imaging by using X-ray imaging, and 3-D nano optoelectronics/photonics based on organic nanowires. We are open positions for new graduate students, undergraduate students, & post-doc.

If you are interested, contact us anytime.
 
Contact
Professor: jhje@postech.ac.kr, 054-279-2143
Student: lemona@postech.ac.kr, 054-279-2818


Research Area (Open poisition)

① Liquid Drop impact
 Drop impact(Figure. 1) phenomena have been extensively studied experimentally and theoretically, not only due to the fundamental interest involved, but also due to its importance in a variety of industrial applications. Drop impact is also a good model system of complex fluid for studying various ultrafast phenomena associated with interfaces, such as the formation, coalescence, and breakup of interfaces. 
 Generally, drop impact happens in a very rapid timescale and very small space. In order to exactly track the ultrafast morphological evolution of air/liquid interfaces, high-speed X-ray phase-contrast imaging was developed. Air dynamics, vortex flow dynamics, and splashing dynamics will be extensively studied, as motivated by the successful work on solid surfaces in previous works.

Representative publications
: How Does an Air Film Evolve into a Bubble During Drop Impact? Physical Review Letters, 109, 204501 (2012)
: Size limits the formation of liquid jets during bubble bursting, Nature Communications, 2, 367 (2011)
 

② 3D foam dynamics
 Foam, specifically dry liquid foam, is a type of diphasic system consisting of many air bubbles as dispersed phase and liquid as continuous phase. Liquid foam consists of multiple interfaces of air and liquid and is thus a good model to study complicated 3-D interfaces, including cellular structures that are abundant in biological system and natural materials. Fast X-ray microtomography will be developed for dynamics of liquid foam (Figure. 2), in particular, to investigate‘foam growth’ including the fundamental issues of growth dynamics of individual bubbles and diffusion of air through interfaces.

③ Plant cell growth

 Growth of plant cell (Figure. 3) walls has been studied theoretically, but almost unexplored experimentally because of the absence of proper imaging tools. We target to directly visualize the growth of individual plant cells in 3D, based on using the advanced real-time 3D imaging method. Based on successful 3D volume-rendered images, we plan to analyze the cell growth of individual cells quantitatively. Then, we will try to elucidate possible growth mechanisms of the cells in 3D, based on quantitative analysis of the cell growth patterns as a function of growth time.

④ Nanowire-based cell endoscopy
 Imbalance of intracellular copper homeostasis is closely associated with severe neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Thus, developing a new method to monitor concentration and distribution of copper in a single living cell is critical for better understanding roles of copper in neurological system and providing appropriate biomedical treatments. Up to now, most current approaches to measure copper at a single-cell level are based on using biofunctionalized nanoparticles dispersed, however, which can potentially lead to cytotoxicity and, furthermore, poor resolution by substantial light scattering. we develop a nanowire endoscope (Figure. 4) for intracellular detection of copper based on a organic nanowire waveguide (< 400 nm in diameter), which allows for in-vivo, noninvasive, and high spatial resolution analysis of copper in a living cell.

⑤ C. elegans behaviral gentics
 The nematode Caenorhabditis elegans is a widely used model for genetic dissection of animal behaviors. Despite extensive technical advances in imaging methods, it remains challenging to visualize and quantify C. elegans behaviors in three-dimensional (3-D) natural environments.
 We developed an innovative 3-D imaging method (Figure. 5) that enables quantification of C. elegans behavior in 3-D environments. Furthermore, for the first time, we characterized 3-D-specific behavioral phenotypes of mutant worms that have defects in head movement or mechanosensation. This approach allowed us to reveal previously unknown functions of genes in behavioral regulation. We expect that our 3-D imaging method will facilitate new investigations into genetic basis of animal behaviors in natural 3-D environments.

Representative publications
: Dissection of C. elegans behavioral genetics in 3-D environments, Scientific Reports, 5, 09564 (2015)
: 3-D Worm tracker for freely moving C. elegans, Plus One, 8, e57484 (2013)
 


 
 
Pohang University of Science & Techology San 31, Hyojadong, Pohang 790-784, Republic of Korea   
 
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