Authenticated file broadcast protocol

The File Broadcast Protocol (FBP) was developed as a part of the DETIboot system. DETIboot allows a host to broadcast an operating system image through an 802.11 wireless network to an arbitrary number of receivers. Receivers can load the image and immediately boot a Linux live session. The initial version of FBP had no security mechanisms. In this paper we present an authentication protocol developed for FBP that ensures a correct file distribution from the intended source to the receivers. The performance valuations have shown that, with the best operational configuration tested, the file download time is increased by less than 5%

DETIboot: a fast, wireless system to install operating systems on students laptops

This work presents a system conceived to deploy temporary Linux systems into an unlimited number of client hosts using a Wi-Fi source station (DETIboot server). The ultimate goal of this system is to provide a simultaneous and just-in-time installation of a custom Linux distribution on several tens of laptops for being used in classes or exams. DETIboot uses a server to endlessly broadcast a custom Linux distribution at maximum Wi-Fi transmission speed, using an ad-hoc network topology to reach all nearby target systems wishing to install it. To deal with packet losses and avoid feedback from the client hosts, we used Fountain Codes. With these codes, client hosts can start at any time the reception and the expected time for completing the download is mainly a function of the number of codewords (wireless frames) effectively received. Field tests were done to evaluate the performance of our system and in average it took around 69 seconds to download a custom Linux image (based on Slax) with a size of 225 MiB

Basic building blocks development for a SiN platform in the visible range

Integrated silicon photonics in the visible range is one of the areas that is emerging and growing in the market for different applications, such as: biosensing, optogenetics, quantum computing, imaging and display, fluorescence microscopy, cytometry, tomography, LIDAR and Lifi. Here, we present the first steps to build a process design kit of components in the visible range centered at 633 nm using a LPCVD silicon nitride platform. The first basic elements are presented (grating couplers, single mode waveguides and a MMI)

Lanthanide-DTPA grafted silica nanoparticles as bimodal-imaging contrast agents.

The design and synthesis of a combined MRI-optical probe for bio-imaging are reported. The materials studied join the properties of lanthanide (Ln(3+)) complexes and nanoparticles (NPs), offering an excellent solution for bimodal imaging. The hybrid SiO(2)@APS/DTPA:Gd:Ln (Ln = Eu(3+) or Tb(3+)) (APS: 3-aminopropyltriethoxysilane, DTPA: diethylenetriamine pentaacetic acid) system increases the payload of the active magnetic centre (Gd(3+)) and introduces a Ln(3+) long-life excited state (Eu(3+): 0.35 ± 0.02 ms, Tb(3+): 1.87 ± 0.02 ms), with resistance to photobleaching and sharp emission bands. The Eu(3+) ions reside in a single low-symmetry site. Although the photoluminescence emission is not influenced by the simultaneous presence of Gd(3+) and Eu(3+), a moderate r(1) increase and a larger enhancement of r(2) are observed, particularly at high fields, due to susceptibility effects on r(2). The presence of Tb(3+) instead of Eu(3+) further raises r(1) but decreases r(2). These values are constant over a wide (5-13) pH range, indicating the paramagnetic NPs stability and absence of leaching. The uptake of NPs by living cells is fast and results in an intensity increase in the T(1)-weighted MRI images. The optical properties of the NPs in cellular pellets are also studied, confirming their potential as bimodal imaging agents

Lanthanide-DTPA grafted silica nanoparticles as bimodal-imaging contrast agents.

The design and synthesis of a combined MRI-optical probe for bio-imaging are reported. The materials studied join the properties of lanthanide (Ln(3+)) complexes and nanoparticles (NPs), offering an excellent solution for bimodal imaging. The hybrid SiO(2)@APS/DTPA:Gd:Ln (Ln = Eu(3+) or Tb(3+)) (APS: 3-aminopropyltriethoxysilane, DTPA: diethylenetriamine pentaacetic acid) system increases the payload of the active magnetic centre (Gd(3+)) and introduces a Ln(3+) long-life excited state (Eu(3+): 0.35 ± 0.02 ms, Tb(3+): 1.87 ± 0.02 ms), with resistance to photobleaching and sharp emission bands. The Eu(3+) ions reside in a single low-symmetry site. Although the photoluminescence emission is not influenced by the simultaneous presence of Gd(3+) and Eu(3+), a moderate r(1) increase and a larger enhancement of r(2) are observed, particularly at high fields, due to susceptibility effects on r(2). The presence of Tb(3+) instead of Eu(3+) further raises r(1) but decreases r(2). These values are constant over a wide (5-13) pH range, indicating the paramagnetic NPs stability and absence of leaching. The uptake of NPs by living cells is fast and results in an intensity increase in the T(1)-weighted MRI images. The optical properties of the NPs in cellular pellets are also studied, confirming their potential as bimodal imaging agents