You are invited to attend a lecture on Tuesday, July 18^th, 2023 15:00

Room 512, "Tochna" Building, Faculty of Engineering

DEEP-SUBWAVELENGTH DIRECTION-OF-ARRIVAL DETECTION WITH

ENHANCED PERFORMANCE USING TIME MODULATION

By:

Tamir Zchut Oskar

MSc student under the supervision of  Dr. Yarden Mazor

Abstract                   

In recent years, the interaction between electromagnetic waves and time-modulated systems has gained interest and research attention. Incorporating temporal variation allows for additional control over the system response, followed by the possibility to go beyond the known abilities of passive systems. Contemporary uses of such systems include aviation and military radars. In this work, we study the physical mechanisms that allow sensitivity enhancement of a time-modulated 2D dimer, for deep-subwavelength Direction of Arrival (DoA) sensing. Our 2D dimer is constructed from two infinite wires with periodic loading,
and the temporal modulation is achieved by incorporating a time-modulated capacitor as part of the periodic loading impedance. We formulate the scattering problem from the 2D dimer using an analytical model for the scattering from a single loaded wire. Then, we define a performance metric to facilitate a quantitative discussion of the sensitivity. We explore physical phenomena which cause the sensitivity enhancement and identify three separate operation regimes, each dominated by a specific physical mechanism: frequency conversion, which translates the incident wave to a resonance frequency; High-frequency sensitivity ripples; and parametric amplification. We study the high harmonies generated in the dimer wires and the information that can be retrieved from them. The energy that is received and scattered from the system is calculated, giving us a better understanding of the physical interactions in the system, and allowing us to study the frequency conversion efficiency. We demonstrate the difference in working in different fundamental frequencies and the energy balance as a function of the DoA. We show that time modulation allows for a new degree of freedom which can be used to optimize the sensor for a wide range of
frequencies, allowing wide-band operation.

Using MRI to probe inside the broken heart

Prof. Moriel Vandsburger

Department of Bioengineering, U.C. Berkeley, Berkeley, CA, USA

Time: Sunday July 2, 2023 16:00 Israel Time

Abstract

Emerging treatments for heart failure including gene therapy and reparative cell therapy seek to improve cardiac function or replace lost myocardium via targeting of genetic, cellular, and tissue scale mechanisms. Within clinical settings, imaging modalities including cardiac magnetic resonance imaging (MRI) are used to assess the subsequent impact on global ventricular structure and function, and changes in dense scar tissue. Although such measurements can be performed non-invasively and serially, the macro-level imaging measurements derived from such scans reflect the aggregate effects of changes at the molecular, cellular and tissue levels. Subsequently, when promising therapies fail to demonstrate efficacy, the source of failure often remains unknown. The absence of suitable imaging methodologies represents a fundamental barrier to further development of such treatments. In our lab we utilize a first principles approach to unify changes in myocardial MRI physics properties with advanced pulse sequence design and analysis in order to transform cardiac MRI into a multi-scale molecular imaging tool for unmet needs in cardiology. Using a process of chemical exchange saturation transfer (CEST) we have designed pre-clinical methods to quantify gene transfer following adeno associated viral gene therapy, and to longitudinally quantify cell survival/proliferation following intra-myocardial implantation in mouse models of regenerative cell therapy. In addition, cardiac CEST approaches for imaging of myocardial creatine levels and endogenous contrast fibrosis imaging have been translated to clinical application in obese adults and renal failure patients on routine hemodialysis. When integrated, these approaches can enable serially non-invasive and multi-scale analysis from the level of gene expression up to whole organ function in the failing or healing heart.

Bio

Moriel Vandsburger, PhD is the Timothy and Karen Guertin Chair in Bioengineering at the University of California, Berkeley. His lab is focused on developing novel molecular MRI and analytical tools to quantify integrative physiology in mice and humans. The primary focus is on non-ischemic cardiovascular, renal, and musculoskeletal diseases and their interfaces with gene and cell therapies. He is a father to the two most amazing girls in the United States, an avid farmer, outdoorsman, woodworker, and cook. Moriel completed his postdoctoral training with Michal Neeman at the Weizmann Institute between 2010-2013 and would give anything for Sabich Chernihovsky to reopen (sorry Oved, theirs was better).

Zoom meeting details

Time: Jul 2, 2023 04:00 PM Israel Time | 09:00 AM EST | 6:00 AM PDT

https://tau-ac-il.zoom.us/j/7619474829

Meeting ID: 761 947 4829