28.3.16

You are invited to attend a lecture

By

 

 Prof. Rakesh Kumar Singh

 

 

Indian Institute of Space and Technology (IIST) Thiruvananthapuram, Kerala, India

 

 

Non-invasive single-shot imaging through a scattering

 

layer using speckle interferometry

 

 

Optical imaging through complex scattering media is one of the major technical challenges with important applications in many research fields, ranging from biomedical imaging, astronomical imaging, to spatially multiplexed optical communications. Various techniques for imaging though scattering mediums have been proposed and discussed in the past. In this talk, we will discuss a new approach for non-invasive imaging through random scattering medium by speckle interferometry.  Principle of this technique lies on exploiting the complex nature of the two point correlation function of the random fields and combining digital holography with correlation optics.

Application of this technique in single shot and lens less correlation holography will be discussed. Possible extension of speckle interferometry to the vectorial random fields will also be covered in this talk.

 

Monday, March 28, 2016, at 11:00

 

Room 011, Kitot Building

28 במרץ 2016, 11:00 
011 Kitot  
28.3.16

 

זכיה בפרס קדר על הצטיינות יוצאת דופן במחקר מדעי.

20 מרץ 2016

 פרופ' עדי אריה מביה"ס להנדסת חשמל זכה בפרס קדר על הצטיינות יוצאת דופן במחקר מדעי.  הפרס, בסך 30,000 $, ניתן החל משנה שעברה אחת לשנה ל-4 חוקרים בכל התחומים באוניברסיטה, יוענק בטקס מיוחד במושב חבר הנאמנים הקרוב ב-20 למאי בשעה 9 בבוקר.

 

 

27.3.16

You are invited to attend a lecture

By

 

Dr. Igor D. Kaganovich

Plasma Physics Laboratory, Princeton University, NJ 08543, USA*

 

Nonlinear Self-Organized Structures in Plasmas - From Electron Kinetics to Nano Technology

 

Nanomaterials have the potential to revolutionize many fields of science and technology, including electronics, chemical synthesis, energy storage, and environmental and pharmaceutical applications.

Industry is investing billions of dollars to be part of the new material revolution that will come with nanomaterials. However, commercial applications of nanomaterials require reliable, predictable, large-scale and low cost synthesis.

Synthesis by plasma has the potential to satisfy these requirements, as well as to form improved nanomaterials. Plasma synthesis offers the possibility of high throughput, short nanostructure growth time, low cost, and optimized material properties.

These remarkable features of plasma synthesis are in great part due to the ability of plasma synthesis methods to sustain a higher yield production of nanomaterials both in volume and on surfaces, and often at lower process temperature and higher

chemical purity, than conventional chemical synthesis. A critical obstacle toward these goals is the lack of understanding of plasma synthesis processes. It is a joint challenge of plasma and material sciences to understand both plasma operation and

material synthesis with plasma.

In this talk I will give two examples of research performed in this area:

Collective interaction of an electron beam with plasma in etching machines and arc self-organization during nanomaterial synthesis.

 

Sunday, March 27, 2016, at 12:00

Room 011, Kitot Building

 

27 במרץ 2016, 13:00 
Kitot 011  
27.3.16

 

סמינר מחלקתי Rotem Halevi בית הספר להנדסה מכאנית

01 ביוני 2016, 15:00 
וולפסון 206  
0
סמינר מחלקתי Rotem Halevi בית הספר להנדסה מכאנית

 

 

 

 

 

School of Mechanical Engineering Seminar
Wednesday, June 1, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

 

 

MECHANICAL INVESTIGATION OF AORTIC VALVE PROGRESSIVE CALCIFICATION USING REFINED COMPUTATIONAL MODELS

 

Rotem Halevi

 Prof. Rami Haj-Ali

The aortic valve (AV) is a bio-mechanical system responsible for the unidirectional flow between the left ventricle (LV) and the aorta.  Calcific aortic valve disease (CAVD) is characterized by calcification of the AV cusps leading to thickening and stiffening of the cusps' tissue until blood flow to the body is obstructed.  The CAVD affects approximately 30% of adults above 65 years old. 

The important role of mechanical strains/stresses and flow shear stresses (FSSs) in the initiation and regulation of the CAVD progression have been extensively studied.  However, there is lack of data on early stages of CAVD and the parameters of its growth since CAVD is usually asymptomatic until the disease is in advance stage. 

This study employed finite element models (FEMs), computation fluid dynamics (CFDs), fluid-structure interaction (FSI) models, and a mechano-biology models to investigate the calcification development. The study began with investigation the calcifications shapes and defining typical geometries. A new method for simulating the calcification growth based on Computed tomography (CT) scans were developed. Using this method, different stages of CAVD are modeled in numerical analyses. Finally, a newly proposed mechano-biology algorithm was used to predict calcification growth based on cusp strains. All analyses and methods were based on and calibrated to clinical data. The research provides new knowledge on the disease initiation and growth and may help find a better treatment for the disease.

.

 

 

17.3.16

You are invited to attend a lecture

By

 

 

Dr. Moti Fridman

Faculty of Engineering, Bar-Ilan University

 

 

 

Spontaneous PT symmetry breaking

With topological insulators

 

In this talk we present a novel optical isolator based on the interaction of light and

Topological insulators.

 

This optical isolator does not require the application of external magnetic field and is based on spontaneous time reversal symmetry braking by topological insulators.

 

The device is comprised of tapered fiber with Sb2Te3 topological insulating crystal on its surface.

 

The interaction of light with the topological insulator rotates the input polarization in a similar manner to the Faraday rotation, but without the necessity in external magnetic field.

 

 

 

 

Thursday, March 17, 2016, at 15:00

 

Room 011, Wolfson Classroom Building

14 במרץ 2016, 15:00 
 
17.3.16

You are invited to attend a lecture

By

 

 

Dr. Moti Fridman

Faculty of Engineering, Bar-Ilan University

 

 

Spontaneous PT symmetry breaking

With topological insulators

 

In this talk we present a novel optical isolator based on the interaction of light and

Topological insulators.

 

This optical isolator does not require the application of external magnetic field and is based on spontaneous time reversal symmetry braking by topological insulators.

 

The device is comprised of tapered fiber with Sb2Te3 topological insulating crystal on its surface.

 

The interaction of light with the topological insulator rotates the input polarization in a similar manner to the Faraday rotation, but without the necessity in external magnetic field.

 

 

 

 

Thursday, March 17, 2016, at 15:00

 

Room 011, Wolfson Classroom Building

 

16.3.16

16 במרץ 2016, 13:00 
011 kitot  
16.3.16

You are invited to attend a lecture

By

 

Or Danon

(M.Sc. student under the supervision of Prof. Moshe Tur)

School of Electrical Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel

Fast and distributed optical fiber strain sensor using novel Brillouin sensing techniques

Fiber-optic based sensors are a promising technology for implementing Structural Health Monitoring (SHM), as well as many other security applications. Sensors based on the Brillouin effect are already used to monitor strain/temperature variations in long gas pipes, submarine cables, tunnels etc. In sensors based on the concept of Brillouin Optical Time Domain Analysis (BOTDA), the Brillouin Gain Spectrum (BGS) of the fiber is interrogated by launching a probe continuous wave (CW) and a pump pulse, with frequency difference around the Brillouin Frequency Shift (BFS). The probe wave gain time dependency is then translated into spatial dependency of the Brillouin gain along the fiber for the specific frequency difference between the probe and the pump waves. In conventional BOTDA, the BGS is interrogated at multiple points so it can be fully reconstructed. This approach, albeit robust, is time consuming as each reading is limited by twice the Time of Flight (TOF) of the pulse in the fiber. A novel technique suggested by our team called Slope Assisted BOTDA (SA-BOTDA) enables to overcome this limitation by interrogating the BGS at only one frequency, on its slope. The BFS is then calculated by knowing the local slope of the BGS.

The SA-BOTDA method however suffers from several drawbacks. First, in distributed sensing, the BFS may vary significantly along the fiber, causing the singular frequency chosen for interrogation to result in zero gain from some areas of the fiber. Second, changes in the pump power, due to various reasons such as polarization fading, coupling losses, depletion etc., cannot be separated from changes in the BFS, as only one parameter is measured.

In this talk we present recent advances which overcome these limitations. The variation of the BFS along the fiber is countered by varying the probe frequency during the travel of the pump pulse, a method called Tailored Probe BOTDA (TP-BOTDA). We demonstrate first experimental results for real time measuring of a vibrating bent cantilever beam, a realistic and challenging scenario applicable for SHM of UAVs, using state of the art measurement system developed within this thesis. We also present experimental demonstrations of techniques which use Double Slope Assisted BOTDA (DSA-BOTDA) to overcome the dependence of the slope on the pump power.

Wednesday, March 16, 2016, at 13:00

Room 011, Kitot Building

 

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