A wireless instrumentation control system based on low-cost single board computer gateways

Nowadays, most of the automatized measurement processes are carried out by VISA (Virtual Instrument Software Architecture) compatible instruments, that execute the instructions provided by a host computer connected through wired standard buses, as USB (Universal Serial Bus), GPIB (General-Purpose Instrumentation Bus), PXI (PCI eXtensions for Instrumentation) or Ethernet. To overcome the intrinsic limitations associated to these wired systems, this work presents an instrumentation control system based on the IEEE 802.11 wireless communications standard. Intended for instruments having a USB control port, this port is connected to a gateway based on a compact Raspberry Single Board Computer (SBC) and thus the instrument can be connected to the host computer via Wireless Fidelity (WiFi), easily allowing the deployment of an ad-hoc instruments communication network in the working area or its connection to a previously deployed general purpose WiFi network. Developed under Python, the operation commands, wireless link protocol, and USB connection allow two modes of operation to provide system flexibility: a live mode, where commands are sent individually from the host computer to the selected instrument; and a standalone mode, where a full measurement process can be entirely downloaded in the gateway to be autonomously executed on the instrumentation. The system performance in both operation modes, distance of operation, time latencies, and operating lifetime in battery operation have been characterized

Yangian Symmetry for the Tree Amplituhedron

17 pages, 4 figures; v2: extended discussion of results, minor typos corrected, version published in Journal of Physics ATree-level scattering amplitudes in planar N=4 super Yang-Mills are known to be Yangian-invariant. It has been shown that integrability allows to obtain a general, explicit method to find such invariants. The uplifting of this result to the amplituhedron construction has been an important open problem. In this paper, with the help of methods proper to integrable theories, we successfully fill this gap and clarify the meaning of Yangian invariance for the tree-level amplituhedron. In particular, we construct amplituhedron volume forms from an underlying spin chain. As a by-product of this construction, we also propose a novel on-shell diagrammatics for the amplituhedron.Peer reviewe

Effet de la matrice de l'eau sur l'élimination des micropolluants organiques par ozonation. Partie 1. Consommation spécifique de l'ozone dans un réacteur

A partir des réactions possibles entre l'ozone, les radicaux et les principaux composants d'une eau à potabiliser, des formules théoriques de formations de radicaux et de décomposition de l'ozone sont établies. La matière organique est schématisée par les composés qui réagissent avec l'ozone (Si), les initiateurs, les promoteurs et les inhibiteurs de la réaction radicalaire (SIi, Sp,i, Ss,i). La décomposition de l'ozone est ensuite mesurée pour 56 eaux naturelles caractérisées par les analyses suivantes (pH, Absorbance à 254 nm, COT, Alcalinité). En se basant sur les connaissances acquises et les valeurs expérimentales du taux spécifique de consommation de l'ozone w, l'équation théorique est simplifiée et on obtient:-(d[O3]/dt)=([O3](∑kDlSl,i)(∑klDP,i[SP,i])) / ([HCO3-](k9+k10 10pH-10,25))En prenant le COT comme représentatif des [Sp,i] (attaque radicalaire non sélective) et l'absorbance à 254 nm comme representative de SI,i (attaque directe sur les cycles aromatiques), une analyse multifactorielle permet d'obtenir l'expression:log10w = -3,93 + 0,24pH + 0,75 log10 Absorbance à 254 mm + 1,08 log10 COT - 0,19 log10 alcalinitéL'équation ainsi obtenue peut être utilisée dans tous les modèles prédictifs faisant appel aux bilans massiques sur l'oxydant.From the numerous reactions between ozone and other components of raw water in a drinking water plant, we obtain theoretical equations for hydroxy radical concentrations (1) and for the disappearance of ozone (2). Dissolved organic matter is divided in to four components: substances which react with ozone by a direct mechanism (Si), initiators, promotors, and scavengers ofradical reactions (SI,i, SP,i, SS,i). We also take into account the reactions between hydrogen peii*iâô. orThe, and free radicals to simulate advanced oxidation processes.[OH∘]= ([O3]{2k1∙10pH-14+2k2 10pH-11,6 [H2O2] + ∑kdl,i [Sl,i]}) / (klD[P]+[HCO3-] (k9+k10∙10pH-10,25)+∑klDS,i [Ss,i])   (1)-(d[O3])/(dt) = {kD[P]+∑kD,i[Si]+∑kDl,i[Sl,i]+3k110pH-14+k210pH-11,6H2O2]}[O3]+[OH∘]{k8[O3]+[H2O2](k210pH-11,6+K7)+∑klDP,i[SP,i]   (2)For 56 natural water samples, we measured the disappearence of ozone directly in a completely stirred batch reactor. Water samples were characterized by pH, TOC, 254 nm UV absorbance and alkalinity. Kinetics were first order with respect to ozone(d[O3])/(dt) = -w[O3]with w : specific ozone disappearence rate.Each term of equation 2 is discussed and, based on the experimental values of w, a simplified equation 3 obtained :-(d[O3])/(dt) = ([O3](∑kDISl,i)(∑klDP,i[SP,i))/([HCO3](k9+k10 10pH-10,25))The TOC parameter can represent [SP,i] because radical reactions are non selective, where as the 254 nm UV absorbance can represent [Si] because organic matter (Fulvic and Humic acid) can react directly with ozone via its constituent aromatic rings.Using the data set of 56 w values measured in natual water samples, mathematical correlations can be calculated :log10w = -3,93 + 0,24pH + 0,75 log10 Absorbance à 254 mm + 1,08 log10 COT - 0,19 log10 alcalinityA strong correlation between experimental measurements and predicted w values is obtained

Effet de la matrice de l'eau sur l'élimination des micropolluants organiques par ozonation. Partie 2. Simulation de l'élimination d'un micropolluant dans les réacteurs idéaux

L'équation cinétique qui permet de calculer l'oxydation d'un micropolluant dans les réacteurs d'ozonation s'écrit:-(d[P]/dt)=(KD[O3]L+KID[OH∘])[P]Kd et Kid: constantes de vitesse de l'ozone et des radicaux hydroxyles sur le micropolluant P.Dans la première partie, l'approche théorique de la concentration en radicaux hydroxyles a montré que [OH·] est proportionnel à la concentration en ozone ([OH·] = k'[03]). On a donc:(d[P]/dt)=KG[O3]L[P] with KG=KD+KIDK'Dans un réacteur parfaitement agité, les concentrations en ozone et en micropolluant sont constantes et l'élimination s'écrit: ([P]/[Po])=(1/1+KG[O3]L τ) with τ=(V/Q)Dans un réacteur piston, les concentrations varient tout au long de la colonne et il est habituel de modéliser un tel réacteur comme un grand nombre de R.P.A. en série de volume DeltaV et de hauteur DeltaH (Dans notre approche DeltaH = 0,01 m).Dans les deux cas, la simulation de l'élimination du micropolluant est basée sur la connaissance de la valeur de kG et de la concentration en ozone dans l'eau [03]L[03]L est obtenue de la résolution des bilans massiques dans un volume V ou ~V. ozone à l'entrée + ozone transféré = ozone à la sortie + ozone consomméL'ozone transféré utilise pour son calcul des relations semi-empiriques donnant la constante de Henry et la valeur du kLa.L'ozone consommé est déduit de la relation établie dans la partie 1:(d[O3]L/dt)=w[O3]LLes résultats de la simulation sont comparés aux résultats expérimentaux obtenus avec un pesticide organo-phosphoré, le parathion. Les paramètres variables sont le temps de contact (300 - 600 s), le pH (6,7 - 8,2) et le taux de traitement (1 à 5 g/m3).Une valeur de kG comprise entre 500 et 600 M-¹s-¹ donne une bonne corrélation entre les valeurs expérimentales et calculées. Cependant, on peut noter quelques différences, en particulier dans la partie basse de la colonne, ce qui montre la nécessité de prendre en compte pour des calculs plus précis l'hydrodynamique du réacteur. L'emploi du programme de simulation permet de tracer deux abaques qui montrent l'influence pour n'importe quel micropolluant des facteurs kGteta et w.Micropollutant (P) oxidation in an ideal ozonation reactor uses the kinetic équation:(d[P]/dt)=(KD[O3]L+KID[OH∘])[P]kD and kID : kinetic rate constant of ozone and hydroxy radicals on the micro -pollutant P.In part 1, the theoritical équation shows that [OH°] is proportional to the ozone concentration ([OH°] = k'[O3]) and thus the following equation is obtained :(d[P]/dt)=KG[O3]L[P] with KG=KD+KIDK'In a completely stirred tank reactor, ozone concentration in liquid phase is constant and pesticide elimination is given by the equation :([P]/[Po])=(1/1+KG[O3]L τ) with τ=(V/Q)In a plug flow reactor, ozone concentration in liquid phase varies along the column. To modelize them, we use the model of completely stirred tank reactors in series where the unit volume is ∆V. In our calculations, this volume is obtained by S (reactor cross section area) and ∆h equal to 0,01 m. In this volume ∆V, ozone and micropoliutant concentrations are considerad as a constant.Simulation calculations are based on the knowledge of global kinetic constant kG and ozone concentration.The value of the ozone concentration is obtain from mass balances on the oxklant (on a ∆V or V volume reactor) :ozone inlet + transferred ozone = consumed ozone + ozone outletThe quantifies of transferred ozone are calculated from the Henry law and a semi empirical kLa equation.The quantity of consumed ozone is calculated from the equation in part I(d[O3]L/dt)=w[O3]LExperimental results are obtained with parathion, an organo-phosphorus pesticide on a bubble column pilot plant:Parameters are contact time (300-600 s), pH (6,7-8-2) and ozone treatment rate (1 to 5 g/m3).A kG value of 500 or 600 M-l s-l shows a good correlation between predicted and simulated pesticide concentrations.However, there are noticable differences, especially at the bottom of the column. This shows the necessity to take into account the hydrodynamic properties of the reactor during next works. The use of the simulation program lets to calculate the elimination of pesticide versus the two main parameters : the factor kGteta and the value of w

Tree-level scattering amplitudes from the amplituhedron

7 pages, 2 figures, to be published in the Journal of Physics: Conference Series. Proceedings for the "7th Young Researcher Meeting", Torino, 2016A central problem in quantum field theory is the computation of scattering amplitudes. However, traditional methods are impractical to calculate high order phenomenologically relevant observables. Building on a few decades of astonishing progress in developing non-standard computational techniques, it has been recently conjectured that amplitudes in planar N=4 super Yang-Mills are given by the volume of the (dual) amplituhedron. After providing an introduction to the subject at tree-level, we discuss a special class of differential equations obeyed by the corresponding volume forms. In particular, we show how they fix completely the amplituhedron volume for next-to-maximally helicity violating scattering amplitudes.Peer reviewe

Towards the Amplituhedron Volume

21 pages; v2: version published in JHEPIt has been recently conjectured that scattering amplitudes in planar N=4 super Yang-Mills are given by the volume of the (dual) amplituhedron. In this paper we show some interesting connections between the tree-level amplituhedron and a special class of differential equations. In particular we demonstrate how the amplituhedron volume for NMHV amplitudes is determined by these differential equations. The new formulation allows for a straightforward geometric description, without any reference to triangulations. Finally we discuss possible implications for volumes related to generic N^kMHV amplitudes.Peer reviewe

Both cis and trans Activities of Foot-and-Mouth Disease Virus 3D Polymerase Are Essential for Viral RNA Replication

The Picornaviridae is a large family of positive-sense RNA viruses that contains numerous human and animal pathogens, including foot-and-mouth disease virus (FMDV). The picornavirus replication complex comprises a co-ordinated network of protein-protein and protein-RNA interactions involving multiple viral and host-cellular factors. Many of the proteins within the complex possess multiple roles in viral RNA replication, some of which can be provided in trans (i.e. via expression from a separate RNA molecule), whilst other are required in cis (i.e. expressed from the template RNA molecule). In vitro studies have suggested that multiple copies of the RNA-dependent RNA-polymerase (RdRp), 3D, are involved in the viral replication complex. However, it is not clear whether all these molecules are catalytically active or what other function(s) they provide. In this study, we aimed to distinguish between catalytically-active 3D molecules and those which build a replication complex. We report a novel non-enzymatic cis-acting function of 3D that is essential for viral genome replication. Using a FMDV replicon in complementation experiments, our data demonstrate that this cis-acting role of 3D is distinct from the catalytic activity, which is predominantly trans-acting. Immunofluorescence studies suggest that both cis- and trans acting 3D molecules localise to the same cellular compartment. However, our genetic and structural data suggest that 3D interacts in cis with RNA stem-loops that are essential for viral RNA replication. Together, this study identifies a previously undescribed aspect of picornavirus replication complex structure-function and an important methodology for probing such interactions further

Multiscale porous high-temperature heat exchanger using ceramic co-extrusion

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Design and evaluation of the immunogenicity and efficacy of a biomimetic particulate formulation of viral antigens

Subunit viral vaccines are typically not as efficient as live attenuated or inactivated vaccines at inducing protective immune responses. This paper describes an alternative 'biomimetic' technology; whereby viral antigens were formulated around a polymeric shell in a rationally arranged fashion with a surface glycoprotein coated on to the surface and non-structural antigen and adjuvant encapsulated. We evaluated this model using BVDV E2 and NS3 proteins formulated in poly-(D, L-lactic-co-glycolic acid) (PLGA) nanoparticles adjuvanted with polyinosinic:polycytidylic acid (poly(I:C) as an adjuvant (Vaccine-NP). This Vaccine-NP was compared to ovalbumin and poly(I:C) formulated in a similar manner (Control-NP) and a commercial adjuvanted inactivated BVDV vaccine (IAV), all inoculated subcutaneously and boosted prior to BVDV-1 challenge. Significant virus-neutralizing activity, and E2 and NS3 specific antibodies were observed in both Vaccine-NP and IAV groups following the booster immunisation. IFN-γ responses were observed in ex vivo PBMC stimulated with E2 and NS3 proteins in both vaccinated groups. We observed that the protection afforded by the particulate vaccine was comparable to the licenced IAV formulation. In conclusion, the biomimetic particulates showed a promising immunogenicity and efficacy profile that may be improved by virtue of being a customisable mode of delivery

Direct activation of the proton channel by albumin leads to human sperm capacitation and sustained release of inflammatory mediators by neutrophils

Human voltage-gated proton channels (hHv1) extrude protons from cells to compensate for charge and osmotic imbalances due metabolism, normalizing intracellular pH and regulating protein function. Human albumin (Alb), present at various levels throughout the body, regulates oncotic pressure and transports ligands. Here, we report Alb is required to activate hHv1 in sperm and neutrophils. Dose-response studies reveal the concentration of Alb in semen is too low to activate hHv1 in sperm whereas the higher level in uterine fluid yields proton efflux, allowing capacitation, the acrosomal reaction, and oocyte fertilization. Likewise, Alb activation of hHv1 in neutrophils is required to sustain production and release of reactive oxygen species during the immune respiratory burst. One Alb binds to both voltage sensor domains (VSDs) in hHv1, enhancing open probability and increasing proton current. A computational model of the Alb-hHv1 complex, validated by experiments, identifies two sites in Alb domain II that interact with the VSDs, suggesting an electrostatic gating modification mechanism favoring the active “up” sensor conformation. This report shows how sperm are triggered to fertilize, resolving how hHv1 opens at negative membrane potentials in sperm, and describes a role for Alb in physiology that will operate in the many tissues expressing hHv1.Fil: Zhao, Ruiming. University of California at Irvine; Estados UnidosFil: Dai, Hui. University of California at Irvine; Estados UnidosFil: Arias, Rodolfo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: de Blas, Gerardo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Orta, Gerardo. Universidad Nacional Autónoma de México; MéxicoFil: Pavarotti, Martin Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Shen, Rong. University of Chicago; Estados UnidosFil: Perozo, Eduardo. University of Chicago; Estados UnidosFil: Mayorga, Luis Segundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Darszon, Alberto. Universidad Nacional Autónoma de México; MéxicoFil: Goldstein, Steve A. N.. University of California at Irvine; Estados Unido