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Development and Static Mode Characterization of a New Low-Loss AC Switch Based on Super-gain BJT

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Journal of Energy and Power Engineering 2014年第2期8卷 357-364页

作者： Zheng Ren Sebastien Jacques Yubing Song Adelphe Caldeira Guillaume Goubard Ambroise Schellmanns NathalieBatut greman CNRS-UMR 7347 University of Tours Tours 37200 France

This paper deals with an innovative low-loss AC switch, named as TBBS （transistor based bidirectional switch）, based on the association of super-gain BJTs developed by the greman laboratory. The main characterization results of the super-gain BJT are reminded to identify the key parameters that are essential to build the TBBS. A complete characterization database in static mode of this new AC switch is discussed. In particular, its forward and reverse-biased features have been measured to see the evolution of the DC current gain as a function of the current density. The TBBS makes sense when using the super-gain BJT （bipolar junction transistor） in reverse mode. It means that the reverse DC current gain has to be sufficient （at least higher than l compared with the conventional BJT one）. This new AC switch is bidirectional in current and voltage, totally controllable （turn-on and turn-off） and the most attractive solution in terms of on-state power losses. Further, its manufacturing process is as easier as existing device such as triac.

关键词： AC switch BJT super-gain static characterization low power consumption.

New Multilevel Mixed Topology Development to Improve Inverter Robustness for Domestic Photovoltaic Installations

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Journal of Power and Energy Engineering 2013年第5期1卷 1-6页

作者： Sébastien Jacques Adelphe Caldeira Ambroise Schellmanns Zheng Ren Nathalie Batut greman umr-cnrs 7347 University of Tours 7 Avenue Marcel Dassault 37200 Tours France.

Multilevel inverters are well used in grid connected domestic photovoltaic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. However, this kind of inverter has to be modified to both limit common-mode currents and improve the robustness of the system. This paper presents a new mixed 5-level inverter that meets these challenges. The operating principle of the converter is proposed. Several experimental measurements are described to validate this new concept. The output voltage and current and the THD of the output voltage are particularly discussed.

关键词： Domestic PV Applications Common Mode Currents Decoupling Capacitances Mixed 5-Level Inverter

Ba substitution for enhancement of the thermoelectric properties of LaCoO_(3) ceramics(0≤x≤0.75)

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Journal of Advanced Ceramics 2019年第4期8卷 519-526页

作者： Mohamed Ali BOUSNINA Fabien GIOVANNELLI Loic PERRIERE Guillaume GUEGAN Fabian DELORME Université Francois Rabelais de Tours CNRSINSA CVLGREMAN UMR7347IUT de Blois15 rue de la chocolaterieCS2903F-41029 Blois CedexFrance UniversitéParis 13 Sorbonne Paris CiteLaboratoire des Sciences des Procédés et des MatériauxCNRSUPR 340799 avenue J.B.ClémentF-93430 VilletaneuseFrance Institut de Chimie et des Matériaux Paris-Est UMR 7182 CNRS-UPEC2-8 Rue Henri Dunant94320 ThiaisFrance ST Microelectronics 16 Rue Pierre et Marie CurieTours 37100France

In the present work, dense perovskite ceramics were successfully prepared from a series of La1-xBaxCoO3 solid solutions in the range of substitution 0 ≤ x ≤ 0.75 using solid state reaction and conventional sintering. Structural properties of La1-xBaxCoO3 were systematically investigated and thermoelectric properties were measured in the temperature range of 330–1000 K. The results show that the thermoelectric properties of Ba-substituted LaCoO3 depend on x. Indeed, at 330 K, electrical conductivity presents an optimum value for x = 0.25 with a value of σmax ≈ 2.2×105 S·m–1 whereas the Seebeck coefficient decreases when x and/or the temperature increases. The Ba-substituted LaCoO3 samples exhibit p-type semiconducting behaviour. The best power factor value found is 3.4×10–4 W·m–1·K–2 at 330 K for x = 0.075, which is 10% higher than the optimum value measured in La1–xSrxCoO3 for x = 0.05. The thermal diffusivity and thermal conductivity increase with increasing temperature and Ba concentration. La1-xBaxCoO3 shows a maximum figure of merit(ZT = 0.048) for x = 0.05 at 330 K, 25% higher than the best value in La1–xSrxCoO3 compounds.

关键词： perovskite Ba-substituted LaCoO_(3) oxide thermoelectric p-type semiconductor

Evaluation of an Ultrasound-Guided Focused Ultrasound CMUT Probe for Targeted Therapy Applications

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Open Journal of Applied Sciences 2018年第1期8卷 25-45页

作者： Dominique Gross Mathieu Legros Philippe Vince Dominique Certon VERMON SA Tours France Franç ois-Rabelais University CETU Altha&iuml s Technologies Tours France greman umr 7347 Université de Tours CNRS INSA Centre Val de Loire Tours France

Capacitive Micromachined Ultrasonic Transducer (CMUT) technology, which has been widely studied in the field of medical imaging, possesses strong design flexibility due to its manufacturing process. Many applications could benefit from this unique feature, especially those that require different operating ultrasonic frequencies. This article reports on the characterization of the therapeutic low-frequency field provided by an ultrasound-guided focused ultrasound CMUT probe that is connected to a custom ultrasonic scanner for hyperthermia applications. The study begins by mapping the focused ultrasonic beam in the vicinity of the focal spot and a parametric analysis providing the maximum peak-to-peak (PTP) pressure delivered by the probe under different acoustic conditions. The measured maximum PTP pressure at the targeted operating frequency of 1 MHz is 3 MPa, with a maximum of 3.6 MPa at 1.25 MHz. Based on an in vitro setup found in the literature, the temperature elevation at the focal point was measured, showing results in agreement with the targeted applications (max. ΔT = 7.5°C). The article concludes with a reliability study considering the delivered pressure and the self-heating of the CMUT probe: the results show the good stability of the pressure amplitude over 1.8 × 109 cycles at a duty cycle of 40%, with a moderate internal heating of 3°C.

关键词： Capacitive Micromachined Ultrasonic Transducers CMUT USgFUS Targeted Therapy

A Highly Efficient Algorithm for Phased-Array mmWave Massive MIMO Beamforming

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Computers, Materials & Continua 2021年第10期69卷 679-694页

作者： Ayman Abdulhadi Althuwayb Fazirulhisyam Hashim Jiun Terng Liew Imran Khan Jeong Woo Lee Emmanuel Ampoma Affum Abdeldjalil Ouahabi Sébastien Jacques Department of Electrical Engineering Jouf UniversitySakakaAljouf72388Kingdom of Saudi Arabia Department of Computer and Communication Systems Engineering Faculty of EngineeringUniversiti Putra Malaysia(UPM)Serdang43400Malaysia Department of Electrical Engineering University of Engineering and Technology PeshawarPakistan School of Electrical and Electronics Engineering Chung-Ang UniversitySeoul06974Korea Electrical and Electronic Department Kwame Nkrumah University of Science and TechnologyKumasiGhana umr 1253 iBrainUniversitéde ToursINSERMToursFrance LIMPAF Laboratory Department of Computer ScienceUniversity of BouiraBouira10000Algeria University of Tours(France) GREMAN UMR 7347CNRSINSA Centre Val-de-LoireTours37100France

With the rapid development of the mobile internet and the internet of things(IoT),the fifth generation(5G)mobile communication system is seeing explosive growth in data *** addition,low-frequency spectrum resources are becoming increasingly scarce and there is now an urgent need to switch to higher frequency *** wave(mmWave)technology has several outstanding features—it is one of the most well-known 5G technologies and has the capacity to fulfil many of the requirements of future wireless ***,it has an abundant resource spectrum,which can significantly increase the communication rate of a mobile communication *** such,it is now considered a key technology for future mobile *** communication technology also has a more open network architecture;it can deliver varied services and be applied in many *** contrast,traditional,all-digital precoding systems have the drawbacks of high computational complexity and higher power *** paper examines the implementation of a new hybrid precoding system that significantly reduces both calculational complexity and energy *** primary idea is to generate several sub-channels with equal gain by dividing the channel by the geometric mean decomposition(GMD).In this process,the objective function of the spectral efficiency is derived,then the basic tracking principle and least square(LS)techniques are deployed to design the proposed hybrid *** results show that the proposed algorithm significantly improves system performance and reduces computational complexity by more than 45%compared to traditional algorithms.

关键词： 5G mmWave phased array algorithm antenna beamforming

On-chip excitation of single germanium vacancies in nanodiamonds embedded in plasmonic waveguides

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Light(Science & Applications) 2018年第1期7卷 446-454页

作者： Hamidreza Siampour Shailesh Kumar Valery A.Davydov Liudmila F.Kulikova Viatcheslav N.Agafonov Sergey I.Bozhevolnyi Centre for Nano Optics University of Southern DenmarkCampusvej 55Odense M DK-5230Denmark L.F.Vereshchagin Institute for High Pressure Physics Russian Academy of SciencesTroitskMoscow 142190Russia greman Universitéde ToursUMR CNRS CEA 615737200 ToursFrance

Monolithic integration of quantum emitters in nanoscale plasmonic circuitry requires low-loss plasmonic configurations capable of confining light well below the diffraction *** demonstrated on-chip remote excitation of nanodiamond-embedded single quantum emitters by plasmonic modes of dielectric ridges atop colloidal silver *** nanodiamonds were produced to incorporate single germanium-vacancy(GeV)centres,providing bright,spectrally narrow and stable single-photon sources suitable for highly integrated *** electron-beam lithography with hydrogen silsesquioxane(HSQ)resist,dielectric-loaded surface plasmon polariton waveguides(DLSPPWs)were fabricated on single crystalline silver plates to contain those of deposited nanodiamonds that are found to feature appropriate single GeV *** low-loss plasmonic configuration enabled the 532-nm pump laser light to propagate on-chip in the DLSPPW and reach to an embedded nanodiamond where a single GeV centre was *** remote GeV emitter was thereby excited and coupled to spatially confined DLSPPW modes with an outstanding figure-of-merit of 180 due to a~six-fold Purcell enhancement,~56%coupling efficiency and~33μm transmission length,thereby opening new avenues for the implementation of nanoscale functional quantum devices.

关键词： excitation silver thereby

Characterization and Modeling Home Power Grid Topologies in PLC Broadband

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Journal of Control Science and Engineering 2014年第2期2卷 70-79页

作者： Richard Nizigiyimana Annuar Achouri Jean-Charles Le Bunetel Yves Raingeaud Philippe Ravier Guy Lamarque greman (Research Group on Materials Mieroelectronics and Acoustics Nanotechnology) University of Tours Tours 37200France

Home power outlets can be connected in various topologies： derivation, star, cascade. This paper firstly describes the intrinsic behavior of the transfer function of these basic topologies. Secondly, the channel capacities of the three topologies are compared to check if there is a more favorable topology. Many deterministic modeling methods have been developed to compute the transfer function of power line networks but the given examples in the studies correspond only to the derivation topology with branches connected to the direct path between transceivers. Thirdly, this paper evaluates the ability of common modeling methods （multipath and chain matrices） to compute accurately the transfer function of any topology. Modeling the derivation topology with ＂secondary＂ branches and the star topology is shown to be inappropriate with chain matrices based method. Indeed, this method is very sensitive to the uncertainty of the second parameters of the power cables and this induces considerable fading shifts for those topologies. Multipath modeling method produces results agreeing with measurements for any topology.

关键词： Power sockets topologies power line channel capacity multipath model chain matrices model.

An Overview on Materials and Techniques in 3D Bioprinting Toward Biomedical Application

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Engineered Regeneration 2021年第1期2卷 1-18页

作者： S.Vanaei M.S.Parizi S.Vanaei F.Salemizadehparizi H.R.Vanaei greman INSA Centre Val de LoireBlois 41000France Nano Bioelectronics Devices Lab Cancer Electronics Research GroupSchool of Electrical and Computer EngineeringFaculty of EngineeringUniversity of TehranTehranIran Department of Biomedical Engineering Rochester Institute of TechnologyRochesterNYUnited States Arts et Metiers Institute of Technology CNAMLIFSEHESAM UniversityParisFrance Arts et Metiers Institute of Technology CNRSCNAMPIMMHESAM UniversityParisFrance

Three-dimensional(3D)bioprinting,an additive manufacturing based technique of biomaterials fabrication,is an innovative and auspicious strategy in medical and pharmaceutical *** ability of producing regenerative tissues and organs has made this technology a pioneer to the creation of artificial multi-cellular tissues/organs.A broad variety of biomaterials is currently being utilized in 3D bioprinting as well as multiple techniques employed by *** this review,we demonstrate the most common and novel biomaterials in 3D bioprinting technology further with introducing the related techniques that are commonly taking into account by *** addition,an attempt has been accomplished to hand over the most relevant application of 3D bioprinting techniques such as tissue regeneration,cancer investigations,*** presenting the most important *** main aim of this review paper is to emphasis on strengths and limitations of existence biomaterials and 3D bioprinting techniques in order to carry out a comparison through them.

关键词： 3D bioprinting Biology Biomaterial Bioinks Tissue engineering Organ regeneration

Influence of Bi on the thermoelectric properties of SrTiO_(3-d)

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Journal of Materiomics 2019年第1期5卷 88-93页

作者： Cong Chen Mohamed Bousnina Fabien Giovannelli Fabian Delorme Universite de Tours CNRSINSA CVLGREMAN UMR 7347IUT de Blois15 rue de la chocolaterieCS 290341029Blois CedexFrance Bundesanstalt für Materialforschung und eprüfung(BAM) Unter den Eichen 8712205BerlinGermany

The thermoelectric properties of Sr1-xBixTiO_(3-δ)(0≤x≤0.07)have been *** ceramics of Sr1-xBixTiO_(3-δ) and Sr0.95TiO_(3-δ) have been prepared by solid-state reaction and conventional sintering in air followed by annealing in a reducing *** and SEM analyses show that the rutile TiO_(2 i)n Sr_(0.95)TiO_(3) formed after sintering becomes Magneli phase of TinO_(2n-1) after ***,Bi resolves from Sr1-xBixTiO_(3 )after annealing,resulting in the formation of Sr1-xBixTiO_(3-δ)/Bi/TinO_(2n-1) *** increasing Bi content in Sr1-xBixTiO_(3-δ),the electrical conductivity increases while the absolute values of the Seebeck coefficient decrease as a result of increasing carrier *** thermal conductivity of SrTiO_(3-δ) is reduced by doping Bi up to x=*** ZT~0.13 is obtained in Sr0.93Bi0.07TiO_(3-δ) at 1000 K.

关键词： Thermoelectrics SrTiO_(3) Composite Bi Magneli phase