Modélisation et réalisation d’un système de récupération d’énergie imprimé : caractérisation hyperfréquence des matériaux papiers utilisés

The work presented in this thesis is part of microwave energy harvesting theme, applied to supply electrochromic displays for anti-counterfeiting applications. This study focuses on the design, optimization and implementation of rectennas (rectifying antennas) printed on cellulosic substrates with industrial printing techniques.Characterization of dielectric materials (paper) and conductors has been developed. The combination between the transmission line technique and the resonant cavity allowed the characterization of a flexible and copper free substrate over a wideband (500 MHz to 3 GHz). Dielectric losses of paper are too high to perform HF circuits. A wise choice of the substrate and of the optimization technique for circuit design enables performant rectennas.Two compact rectennas were developed in microstrip technology at 2.45 GHz, optimized and printed with flexography method using a single layer of conductive ink. The rectennas do not contain vias or HF side filter or DC side filter. The first rectenna was printed on corrugated paper. The output DC voltage across the display reaches 0.5 V for a power level at the input of the rectenna of -10 dBm. The second rectenna is a 3D rectenna, printed on flexible 100 µm thick plastic substrate. A DC voltage of 1 V was measured across the display when getting near a Smartphone on Wi-Fi mode. The rectennas are suitable for both near field and far field.Les travaux présentés dans ce mémoire s'inscrivent dans la thématique de la récupération d'énergie hyperfréquence, appliquée à la réalisation d'un circuit électronique imprimé sur papier permettant l'alimentation d'afficheurs électrochrome, ceci dans le cadre de la lutte contre la fraude. Cette étude porte plus particulièrement sur la conception, l'optimisation et la réalisation de rectennas (rectifying antennas) imprimées sur support cellulosique et réalisées avec des méthodes d'impression industrielles.La caractérisation des matériaux diélectriques (support papier) et conducteurs a été développée. L'association de la technique des lignes de transmission et de la cavité résonante a permis la caractérisation d'un substrat souple et non cuivré sur une bande de 500 MHz à 3 GHz. Le papier présente des pertes diélectriques contraignantes pour la conception de circuits en hautes fréquences. Un choix judicieux du substrat et une conception optimisée du circuit ont permis de réaliser des circuits de conversion d'énergie sur papier à l'état de l'art international.Deux rectennas compactes ont été développée, en technologie micro-ruban, optimisées et imprimées avec la méthode flexographie utilisant une unique couche d'encre conductrice. Elle fonctionne à 2.45 GHz et elles ne contiennent pas de vias de retour à la masse ni de filtre côté HF, ni de filtre côté DC. La première a été imprimée sur papier carton ondulé. Les tensions de sortie aux bornes de l'afficheur atteignent les 0.5 V pour des niveaux de puissance à l'entrée de la rectenna de l'ordre de -10 dBm. La deuxième rectenna a été imprimée sur support plastique flexible ayant 100 µm d'épaisseur afin de réaliser des rectennas 3D. Une tension DC de 1 V a été mesurée aux bornes de l'afficheur lorsqu'on approche un Smartphone fonctionnant en mode Wi-Fi. Les rectennas réalisées sont adaptées à la fois pour le champ proche et lointain

Non-classical human leukocyte antigen class I in Tunisian children with autism

Autism spectrum disorders (ASD) are one of the most common childhood morbidities characterized by deficits in communication and social skills. Increasing evidence has suggested associations between immune genes located in the human leukocyte antigen (HLA) complex and etiology of autism.In this study, we investigated whether the non-classical class I HLA-G, -E, and -F polymorphisms are associated with genetic predisposition to autism in Tunisia. We aimed to find a correlation between HLA-G genotypes and soluble HLA-G (sHLA-G) levels. We have analyzed the HLA-G, -E, and -F genotypes of 15 autistic children and their parents. DNA typing of HLA class I genes was performed using PCR-SSP and PCR-RFLP methods. Also, we evaluated the serum levels of HLA-G (1 and 5) by a validated ELISA technique in autistic probands and their parents.No association was found between any polymorphism and autism in the study subjects. Additionally, we found no correlation between sHIA-G1 and sHLA-G5 and autism. Also, no significant difference in sHIA-G testing in parents and offspring was found. However, parents carrying [GG] genotype presented a higher sHLA-G levels than those carrying ([CC]+[GC]) genotypes (p = 0.037).From this preliminary study, we conclude that the investigated polymorphisms of HLA-G, -E, and -F genes did not lead to autism susceptibility in Tunisian children. However, the CGTIGA haplotype was found to be associated with the disease

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Design and realization of printed energy harvesting circuits : microwave characterization of paper substrates

Les travaux présentés dans ce mémoire s'inscrivent dans la thématique de la récupération d'énergie hyperfréquence, appliquée à la réalisation d'un circuit électronique imprimé sur papier permettant l'alimentation d'afficheurs électrochrome, ceci dans le cadre de la lutte contre la fraude. Cette étude porte plus particulièrement sur la conception, l'optimisation et la réalisation de rectennas (rectifying antennas) imprimées sur support cellulosique et réalisées avec des méthodes d'impression industrielles.La caractérisation des matériaux diélectriques (support papier) et conducteurs a été développée. L'association de la technique des lignes de transmission et de la cavité résonante a permis la caractérisation d'un substrat souple et non cuivré sur une bande de 500 MHz à 3 GHz. Le papier présente des pertes diélectriques contraignantes pour la conception de circuits en hautes fréquences. Un choix judicieux du substrat et une conception optimisée du circuit ont permis de réaliser des circuits de conversion d'énergie sur papier à l'état de l'art international.Deux rectennas compactes ont été développée, en technologie micro-ruban, optimisées et imprimées avec la méthode flexographie utilisant une unique couche d'encre conductrice. Elle fonctionne à 2.45 GHz et elles ne contiennent pas de vias de retour à la masse ni de filtre côté HF, ni de filtre côté DC. La première a été imprimée sur papier carton ondulé. Les tensions de sortie aux bornes de l'afficheur atteignent les 0.5 V pour des niveaux de puissance à l'entrée de la rectenna de l'ordre de -10 dBm. La deuxième rectenna a été imprimée sur support plastique flexible ayant 100 µm d'épaisseur afin de réaliser des rectennas 3D. Une tension DC de 1 V a été mesurée aux bornes de l'afficheur lorsqu'on approche un Smartphone fonctionnant en mode Wi-Fi. Les rectennas réalisées sont adaptées à la fois pour le champ proche et lointain.The work presented in this thesis is part of microwave energy harvesting theme, applied to supply electrochromic displays for anti-counterfeiting applications. This study focuses on the design, optimization and implementation of rectennas (rectifying antennas) printed on cellulosic substrates with industrial printing techniques.Characterization of dielectric materials (paper) and conductors has been developed. The combination between the transmission line technique and the resonant cavity allowed the characterization of a flexible and copper free substrate over a wideband (500 MHz to 3 GHz). Dielectric losses of paper are too high to perform HF circuits. A wise choice of the substrate and of the optimization technique for circuit design enables performant rectennas.Two compact rectennas were developed in microstrip technology at 2.45 GHz, optimized and printed with flexography method using a single layer of conductive ink. The rectennas do not contain vias or HF side filter or DC side filter. The first rectenna was printed on corrugated paper. The output DC voltage across the display reaches 0.5 V for a power level at the input of the rectenna of -10 dBm. The second rectenna is a 3D rectenna, printed on flexible 100 µm thick plastic substrate. A DC voltage of 1 V was measured across the display when getting near a Smartphone on Wi-Fi mode. The rectennas are suitable for both near field and far field

Construction of a smooth Lyapunov function for an asymptotically stable set

summary:In this paper, we analyze the stability of homogeneous delay systems based on the Lyapunov Razumikhin function in the presence of a varying parameter. In addition, we show the stability of perturbed time delay systems when the nominal part is homogeneous

Time domain design for UWB filters

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Time domain design for ultra wideband filters

International audienceIn this article, a time domain method for designing microstrip-line ultra wideband passband filters is presented.From the filter expected specifications, the profile of the nonuniform transmission line is calculated analytically. The filter presented in this article illustrates the proposed method and emphasizes its potential. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1006-1011, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.2592

Conception d'antennes courbées imprimées sur substrat souple pour des rectenna 3D

National audienceDans ce papier, une rectenna compacte 3D est présentée. L'étude porte sur l'impact de la courbure de l'antenne, sur ses performances en termes de rayonnement et fréquence de fonctionnement. Dans le cadre d'un projet de lutte contre la fraude des bouteilles de vin, la rectenna est enroulée autour du goulot d'une bouteille de 25 mm de diamètre. Pour une rectenna de 18.65 cm 3 et avec une puissance incidente de 0.16 mW à la fréquence de 2.45 GHz, la tension DC récupérée est de 600 mV et est suffisante pour activer un afficheur

New Technique for Indoor Location Based on RSSI Method Using UHF RFID Systems

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Time Method Design for Synthesizing UWB Filter

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