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High Responsivity and Ultra-Low Detection Limits in nonlinear a-Si:H p-i-n Photodiodes Enabled by Photogating

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Photonic Sensors 2023年第4期13卷 27-38页

作者： Andreas BABLICH Maurice MÜLLER Rainer BORnEMAnn Andreas nACHTIGAL Peter HARInG BOLÍvar Institute of Graphene-Based nanotechnology University of SiegenHölderlinstr.357076 SiegenGermany Institute of High Frequency and Quantum Electronics University of SiegenHölderlinstr.357076 SiegenGermany

Photodetectors operating at the wavelength in the visible spectrum are key components in high-performance optoelectronic *** this work,massive nonlinearities in amorphous silicon p-i-n photodiodes enabled by the photogating are presented,resulting in responsivities up to 744 mA/W at blue *** detectors exhibit significant responsivity gains at optical modulation frequencies exceeding MHz and a more than 60-fold enhanced spectral response compared to the non-gated *** detection limits down to 10.4 nW/mm^(2) and mean signal-to-noise ratio enhancements of 8.5dB are demonstrated by illuminating the sensor with an additional 6.6μW/mm^(2) red ***-optical simulations verify photocarrier modulation due to defect-induced field screening to be the origin of such high responsivity *** experimental results validate the theory and enable the development of commercially viable and complementary metal oxide semiconductor(CMOS)compatible high responsivity photodetectors operating in the visible range for low-light level imaging and detection.

关键词： Photogating amorphous silicon a-Si:H nonlinearity photodetector responsivity gain

Equivalent circuit for the characterization of the resonance mode in piezoelectric systems

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Journal of Advanced Dielectrics 2015年第4期5卷 37-41页

作者： Y.Fernández-Afonso O.García-Zaldívar F.Calderón-Piñar Centrode Estudios Avanzadosde Cuba Kilómetro 1y 1/2 Carreter a San Antonio de los Baños Valle Grande La LisaHabanaCuba Facultadde Física-Instituto de Cienciay Tecnología de Materiales Universidad de La Habana.San LázaroyL Vedado.La Habana 10400 Cuba CInVESTAV-Unidad Querétaro Libramiento norponiente no.2000 Realde Juriquilla QuerétaroQro.76230México

The impedance properties in polarized piezoelectric can be described by electric equivalent *** classic circuit used in the literature to describe real systems is formed by one resistor(R),one inductance(L)and one capacitance C connected in series and one capacity(C_(0))connected in parallel with the ***,the equation that describe the resonance and anti-resonance frequencies depends on a complex manner of R,L,C and C_(0).In this work is proposed a simpler model formed by one inductance(L)and one capacity(C)in series;one capacity(C_(0))in parallel;one resistor(R_(p))in parallel and one resistor(Rs)in series with other *** the traditional circuit,the equivalent circuit elements in the proposed model can be simply determined by knowing the experimental values of the resonance frequency fr,anti-resonance frequency fa,impedance module at resonance frequency|Z|,impedance module at anti-resonance frequency|Za|and low frequency capacitance C_(0),without ftting the im-pedance experimental data to the obtained equation.

关键词： Piezoelectric equivalent circuit electromechanic

Sustainable Development Project for a Suburban Community Located in Xalapa, Veracruz, Mexico

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Journal of Environmental Science and Engineering(A) 2020年第2期9卷 72-76页

作者： Edmundo Arias Torres Bolívar MArias Olguín Mexican Institute of Appropriate Technology(IMETA) Mexico City 07279Mexico

Rural-urban development project in an ejidal community (portion of common land several owners) is located in the suburban area of Xalapa, Veracruz, *** place where the community is located has a lagoon that was contaminated with water lily. now we want to implement a suburban sustainable development project using ecological and appropriate technologies to the community and the place, taking advantage of that body of water to grow fish and as a recreational area for visitors and thus generating food and economic resources in favor of the community with the food sales, boat rentals and recreational *** project adds to the achievement of 12 of the 17 Sustainable Development Goals of the United nations Organization.

关键词： Sustainable ecosystems appropriate technologies suburban cooperative community empowerment

Polymeric and biological membranes for organ-ona-chip devices

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Microsystems & nanoengineering 2023年第4期9卷 19-43页

作者： Kendra Corral-nájera Gaurav Chauhan Sergio OSerna-Saldívar Sergio OMartínez-Chapa Mohammad Mahdi Aeinehvand School of Engineering and Science Tecnológico de MonterreyAve.Eugenio Garza Sada 2501Monterrey 64849Mexico

Membranes are fundamental elements within organ-on-a-chip(OOC)platforms,as they provide adherent cells with support,allow nutrients(and other relevant molecules)to permeate/exchange through membrane pores,and enable the delivery of mechanical or chemical *** OOC platforms,physiological processes can be studied in vitro,whereas OOC membranes broaden knowledge of how mechanical and chemical cues affect cells and *** with membranes are in vitro microfluidic models that are used to replace animal testing for various applications,such as drug discovery and disease *** this review,the relevance of OOCs with membranes is discussed as well as their scaffold and actuation roles,properties(physical and material),and fabrication methods in different organ *** purpose was to aid readers with membrane selection for the development of OOCs with specific applications in the fields of mechanistic,pathological,and drug testing *** stimulation from liquid flow and cyclic strain,as well as their effects on the cell’s increased physiological relevance(IPR),are described in the first *** review also contains methods to fabricate synthetic and ECM(extracellular matrix)protein membranes,their characteristics(e.g.,thickness and porosity,which can be adjusted depending on the application,as shown in the graphical abstract),and the biological materials used for their *** discussion section joins and describes the roles of membranes for different research purposes and their advantages and challenges.

关键词： testing replace porosity

Dispersion of niquel on the microstructure in magnesium based alloys for hydrogen storage

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Journal of Magnesium and Alloys 2013年第4期1卷 292-296页

作者： A.A.Zaldıvar-Cadena I.Dıaz-Pena J.G.Cabanas-Moreno Universidad Autonoma de nuevo Leon Av.Universidad s/nFacultad de Ingenierıa CivilSan Nicolas de los Garza N.L.C.P.66451Mexico Instituto Politecnico nacional UPALMCol.LindavistaC.P.07338 Mexico D.F.Mexico

Mg–Xwt.%ni(X=5 and 20)alloys have been prepared by mechanical alloying using milling times of 15 and 30 h in a planetary ball milling to know the effects of magnesium with the addition of ni as catalyst,dispersion on the microstructure,area surface and the efficiency of hydrogen ***-EDS,XRD and ImageJ^(■)software have been used to characterize the microstructure and chemical composition of the *** experiments were performed as batch-type tests at 200,250 and 300℃ under 2 MPa H2 pressure during 30 *** experiments resulted in varying amounts of MgH2 in the hydrided powders depending on composition and hydriding *** best results point to an optimum ni dispersion,which in turn depends on ni content and milling time.

关键词： Hydrogen storage Magnesium niquel Alloy Characterization

BiFeO_(3) codoping with Ba,La and Ti:Magnetic and structural studies

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Journal of Advanced Dielectrics 2015年第4期5卷 53-60页

作者： O.García-Zaldívar S.Díaz-Castañón F.J.Espinoza-Beltran M.A.Hernández-Landaverde G.López J.Faloh-Gandarilla F.Calderón-Piñar Facultad de Física-Instituto de Ciencia y Tecnología de Materiales Universidad de La Habana San Láazaro y L VedadoLa Habana 10400Cuba CInVESTAV-Unidad Querétaro Libramiento Norponiente No.2000 Real de JuriquillaQuerétaroQro.76230México Instituto Latino-Americanode Ciênciasda Vidaeda natureza Universidade Federalda Integração Latino-Americana (ILCVN-UNILA)Avenida Tancredo NevesPTIBloco 6 CEP:85866-000-Foz do Iguaçu-ParanaBrazil División Materiales Avanzados Instituto Potosinode Investigación Científica Tecnológica San Luis Potosí CP78216Méexico

Conventional solid state reaction method,from oxides and carbonates,was employed to prepare bismuth(Bi)-based multiferroic *** undoped BiFeO_(3)(BFO)and the codoped system with Ba,La and Ti(Bi_(1-x)Ba_(x)Fe_(1-y)Ti_(y)O_(3),Bi_(1-x-z)Ba_(x)LazFe_(1-y)TiyO_(3))with x,y,z=0.1 were prepared stoichiometrically and sintered at two different *** structural and magnetic properties were investigated at room *** measurements confirm the obtaining of the rhombohedral perovskite structure of the BFO family *** the undoped system,some reflections of undesired phases are present for two different sintering temperatures,while for the doped system only one phase is present for both *** magnetic characterization at room temperature revealed remarkable differences between the ceramic *** results show that for undoped BFO system,spontaneous magnetization is not observed at room ***,in doped one,a well-defined ferromagnetic behavior is observed at room temperature,possible,due to the suppression of the spatially modulated spin structure of BFO promoted by the reduction of the rhombohedral distortion and the weakening of the Bi-O *** XPS results confirm the presence of oxygen vacancies and the coexistence of Fe^(3+)and Fe^(2+) in all the studied *** measurements reveal that the dopant incorporation has not a direct effect in neel temperature but possibly yes in ferroelectric-paraelectric transition.

关键词： Multiferroics XPS magnetic bismuth ferrite BiFeO_(3)

Relaxor ferroelectric behavior:An approach considering both the dipolar and electrical conductivity contributions

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Journal of Advanced Dielectrics 2021年第3期11卷 51-55页

作者： C.Carreras-Casas O.García-Zaldívar A.Peláiz-Barranco Y.González-Abreu F.Calderón-Pinar J.D.S.Guerra Grupo de Materiales Ferroicos Facultad de Física-Instituto de Ciencia y Tecnología de Materiales Universidad de La Habana La Habana 10400Cuba Grupo de Ferroelétricos e Materiais Multifuncionais Instituto de Física Universidade Federal de Uberlandia UberlandiaMinas Gerais38408-100Brazil

The relaxor behavior of PLZT ferroelectric ceramics has been analyzed in a wide frequency and temperature ranges,below and above the temperature for the formation of the so-called polar nano-regions(PnRs).An approximation to the dynamical behavior of the PnRs has been discussed using Cole-Cole’s relaxation model and Jonscher’s Universal Relaxation *** analysis considers both the dipolar contribution and those ones associated with DC and AC electric conductivities,this latter not being previously reported in the literature for relaxor *** effectiveness of the developed model has been verified from the agreement between the experimental data and the theoretical *** study also offers an indirect method to predict the DC component of the electrical conductivity.

关键词： Relaxor ferroelectrics dielectric response modeling conductivity Cole-Cole

Dietary fatty acids and adipose tissue inflammation at the crossroad between obesity and colorectal cancer

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Journal of Cancer Metastasis and Treatment 2019年第8期4卷 29-40页

作者： Lucia Conti Manuela Del Cornò Beatrice Scazzocchio Rosaria varì Massimo D'Archivio Barbara var.no Roberta Masella Sandra Gessani Center for Gender-specific Medicine Istituto Superiore di Sanità 00161 Rome Italy

Excess adiposity, a worldwide-growing pathological condition, is now recognized as a main risk factor for most chronic diseases including colorectal cancer (CRC). Obese subjects show an increased cancer incidence with obesity representing an important indicator of survival, prognosis, recurrence and response to therapy. A low-grade chronic inflammation of metabolically active tissues including the adipose tissue (AT), defined as meta-inflammation, is a main feature of obesity. Fatty acids (FA), the main AT components, are important modulators of inflammation, and the type of FA stored in AT critically affects tissue functions. Their profile within AT mirrors FA dietary intake but also depends on a metabolic control. Obesity, changes in the habitual diet, weight loss or pathological conditions like CRC influence FA profile of AT pointing to these molecules as important actors in AT dysfunction and meta-inflammation, that characterize metabolic diseases and may favor cancer development. Worth of note, diet is receiving growing attention as a main determinant in cancer prevention due to its capacity to modulate immune response and inflammation. Alterations in the balance between different families of FA may contribute to generate a pro-inflammatory profile with deleterious effects on metabolic and immune homeostasis at both local and systemic levels. This review focuses on FA as regulators of human AT inflammation discussing the role of obesity-, diet-, and weight loss-associated changes in FA profile in this process. The relevance of FA composition of AT in linking diet, obesity and CRC will be also reviewed.

关键词： Obesity adipose tissue inflammation diet weight loss fatty acids colorectal cancer

Energy storage and relaxor behavior in(Pb_(0.8)Ba_(0.2))[(Zn_(1/3)nb_(2/3))_(0.7)Ti_(0.3)]O_(3)ferroelectric ceramic

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Journal of Advanced Dielectrics 2023年第6期13卷 45-48页

作者： A.Pelaiz-Barranco Y.Perez-Martín O.García-Zaldívar Y.Gagou Grupo de Materiales Ferroicos Facultad de Física-IMRE Universidad de la Habana.San Lazaroy LVedado.La Habana 10400Cuba LPMC Universite de Picardie Jules Verne 33 rue Saint-Leu80039 Amiens CedexFrance

(Pb_(0.8)Ba_(0.2))[(Zn_(1/3)nb_(2/3))_(0.7)Ti_(0.3)]O_(3)relaxor-type ferroelectric ceramics was obtained via classical solid-state *** hysteresis loop results were discussed in the frame of ergodicity criterium around the characteristic ferroelectric relaxor freezing *** hysteresis loops were observed below the freezing temperature reflecting an ergodic relaxor *** this temperature,estimated around 223K for the studied system,larger and unsaturated like ferroelectric hysteresis loops were *** temperature also coincides with the slope change on maximum polarization and inflection point of remnant polarization *** storage,energy loss and efficiency values were determined in a wide temperature *** the recoverable energy density shows relatively low values(0.23 J/cm^(3)),there are interesting behaviors for this parameter and for the efficiency,since the two physical quantities increase versus temperature and the efficiency even reaches the value of 97%.

关键词： Relaxors ferroelectrics energy storage freezing temperature