1,212 research outputs found
The interaction of Light with Matter and Light with Light
This work consists of two fields of study involving the interaction of light with matter and light with light. The frst part explores the interaction of a superintense laser pulse with an ultrathin solid density foil. The radiation pressure exerted by the laser pulse can be so strong that, in principle, the whole foil is accelerated. This results in the generation of dense, high-flux and collimated and quasimonoenergetic ion beams. However, the onset of transverse instabilities damages the foil, thus resulting in ion spectral broadening. Simple analytical modeling is supported by particle-in-cell (PIC) simulations to strategize methods for instability suppression and ion-beam quality improvement. The second part puts forward a method for detecting the purely quantum electrodynamic process of elastic scattering of real photons in vacuum. Monte-Carlo simulations are used to study the feasibility of detection of this yet undetected process. An experimental setup comprising of a high energy gamma-ray beam colliding with an extreme ultraviolet (XUV) pulse or a free-electron laser (FEL) is utilized. This clean and controllable setup exploits the high gamma photon energies and large laser photon flux for enhancing the probability of scattering events
STABILITY OF SPORE-BASED SENSING SYSTEMS
The full exploitation of bacterial whole-cell biosensing systems in field applications requires the survival of bacterial cells and long term-preservation of their sensing ability during transportation and on-site storage of such analytical systems. Specifically, there is a need for rapid, simple and inexpensive biosensing systems for monitoring human health and the environment in remote areas which often suffer from harsh atmospheric conditions and inadequate commercial distribution and storage facilities. Our laboratory has previously reported the successful use of bacterial spores as vehicles for the long-term preservation and storage of whole-cell biosensing systems at room temperature.
In the present research, we have accomplished a year-long study to investigate the effect of extreme climatic conditions on the stability of spores-based whole-cell biosensing systems. The spores were stored in laboratory conditions that simulated those found in real harsh environments and germination ability and analytical performance of the spore-based sensing systems upon storage in such conditions was monitored. Our results proved that the intrinsic resistance of spores to harsh environmental conditions helped maintain the integrity of the sensor bacteria. The revived active cells actually retained their analytical performance during the course of the twelve-month storage study
The interaction of Light with Matterand Light with Light
This work consists of two fields of study involving the interaction of light with matter and light with light. The first part explores the interaction of a superintense laser pulse with an ultrathin solid density foil. The radiation pressure exerted by the laser pulse can be so strong that, in principle, the whole foil is accelerated. This results in the generation of dense, high-flux and collimated and quasimonoenergetic ion beams. However, the onset of transverse instabilities damages the foil, thus resulting in ion spectral broadening. Simple analytical modeling is supported by particle-in-cell (PIC) simulations to strategize methods for instability suppression and ion-beam quality improvement. The second part puts forward a method for detecting the purely quantum electrodynamic process of elastic scattering of real photons in vacuum. Monte-Carlo simulations are used to study the feasibility of detection of this yet undetected process. An experimental setup comprising of a high energy gamma-ray beam colliding with an extreme ultraviolet (XUV) pulse or a free-electron laser (FEL) is utilized. This clean and controllable setup exploits the high gamma photon energies and large laser photon flux for enhancing the probability of scattering events
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