329 research outputs found

    First report of Cucurbit Chlorotic Yellows Virus (CCYV) and Tomato Leaf Curl New Delhi Virus (ToLCNDV) in Algeria and Lack of Evidence for Seed Transmission of ToLCNDV in Melon and Pumpkin

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    [ES] En este trabajo, se detectó por primera vez el virus de la clorosis amarilla de las cucurbitáceas (CCYV, cucurbit chlorotic yellows virus) infectando pepino y calabacín en Argelia. El CCYV (género Crinivirus, familia Closteroviridae) forma parte de un complejo de virus transmitidos por la mosca blanca Bemisia tabaci, que causan enfermedades de amarillamiento en las cucurbitáceas. Se obtuvo la secuencia completa del gen que codifica la proteína de la cápside (CP) y secuencias parciales de los genes RdRp y Hsp70 de un aislado argelino de CCYV y se compararon con las secuencias presentes en las bases de datos. ToLCNDV (género Begomovirus, familia Geminiviridae) también se detectó por primera vez infectando plantas de cucurbitáceas en Argelia. ToLCNDV es un begomovirus bipartito que causa importantes epidemias en cultivos económicamente valiosos de las familias Solanaceae y Cucurbitaceae. Se obtuvo la secuencia genómica completa de un aislado de ToLCNDV de pepino de Argelia (ToLCNDV-Biskra). La alineación de las secuencias de nucleótidos de los segmentos de ADN-A y ADN-B reveló identidades del 98,7% y 97,6%, respectivamente, con los segmentos de los aislados de la cuenca del Mediterráneo, mientras que la identidad con los aislados de Asia fue de aproximadamente del 90% y 81%. Los aislados presentes en la cuenca mediterránea son monofiléticos y forman un único grupo, mientras que los aislados de la cepa asiática presentan una mayor variabilidad genética y forman varios grupos. Todos los aislados de Argelia mostraron una variación de nucleótidos muy baja. Solo se observó una duplicación de 17 nucleótidos en el ADNB de algunos aislados que daría lugar a una proteína de movimiento 53 aminoácidos más larga, aunque la funcionalidad de esta supuesta proteína es desconocida. A pesar de esa duplicación, no se detectaron eventos de recombinación entre los aislados secuenciados. La baja variación genética podría dificultar la detección de recombinantes.[CA] En aquest treball, es va detectar per primera vegada el virus de la clorosi groga de les cucurbitàcies (CCYV, cucurbit chlorotic yellows virus) infectant cogombres i carabassetes a Algèria. El CCYV (gènere Crinivirus, família Closteroviridae) forma part d'un complex de virus transmesos per mosca blanca que causen malalties d'esgrogueïment en les cucurbitàcies. Es va realitzar la determinació de la seqüència completa de la proteïna de la càpsida (CP) i seqüències parcials dels gens RdRp i Hsp70 d'un aïllat algerià de CCYV i es van comparar amb les seqüències publicades en les bases de dades. ToLCNDV (gènere Begomovirus, família Geminiviridae) també va ser detectat per primera vegada infectant plantes de cucurbitàcies a Algèria. ToLCNDV és un begomovirus bipartit que causa importants epidèmies en cultius econòmicament valuosos de les famílies Solanaceae i Cucurbitaceae. Es va obtindre la seqüència genòmica completa d'un aïllat de ToLCNDV de cogombre d'Algèria (ToLCNDV-Biskra). La alineació de les seqüències de nucleòtids del segments d'ADN-A i ADN-B van mostrar identitats del 98.7% i 97.6%, respectivament, amb els segments corresponents dels aïllats de la conca del Mediterrani, mentre que la identitat amb els aïllats d'Àsia va ser d'aproximadament el 90% i 81%. Els aïllats presents a la conca del Mediterrani són monofilètics i formen un únic grup, mentre que els aïllats de la soca asiàtica presenten una major variabilitat genètica i s'agrupen en diversos grups. Tots els aïllats algerians van mostrar una variació de nucleòtids molt baixa. Només es va observar una duplicació de 17 nucleòtids en d'ADNB d'alguns aïllats que lonaria lloc a una proteïna de moviment 53 aminoàcids més llarga, encara que la funcionalitat d¿aquesta suposada proteïnaés desconeguda. A més, malgrat la duplicació, no es van detectar esdeveniments de recombinació entre els aïllats seqüenciats. La baixa variació genètica podria dificultar la detecció de recombinants.[EN] In this work, cucurbit chlorotic yellows virus (CCYV) was first detected infecting cucumber and zucchini in Algeria. CCYV (genus Crinivirus, family Closteroviridae) is part of a complex of whitefly-transmitted viruses that cause yellowing disease in cucurbits. Determination of the complete CP, and partial RdRp and Hsp70 sequences of an Algerian CCYV isolate was conducted to unveil the evolutionary relationships with the published isolates in databases. The phylogenetic analysis showed that the Algerian isolate clustered into group I together with the majority of the reported CCYV isolates. ToLCNDV (genus Begomovirus, family Geminiviridae) was also detected for the first time infecting cucurbit plants in Algeria. ToLCNDV is a bipartite begomovirus that causes major epidemics in economically valuable crops. epidemics in economically valuable crops of the Solanaceae and Cucurbitaceae families. Cucurbitaceae. The complete genome sequence of a ToLCNDV isolate from Algerian cucumber (ToLCNDV from Algeria (ToLCNDV-Biskra) was obtained. Alignment of the nucleotide sequences of the A-DNA and B-DNA segments revealed the identity of the DNA-A and DNA-B segments revealed identities of 98.7% and 97.6%, respectively, with the segments of the isolates from the Algerian segments of the Mediterranean basin isolates, while the identity with the Asian isolates was approximately 90% and 81%, respectively. was approximately 90% and 81%. The isolates present in the Mediterranean Basin are monophyletic and form a single monophyletic and form a single cluster, whereas isolates from the Asian strain have a higher genetic variability and form several clusters. genetic variability and form several clusters. All isolates from Algeria showed very low nucleotide variation. very low nucleotide variation. Only a duplication of 17 nucleotides was observed in the B-DNA of some isolates which would result in a longer 53 amino acid movement protein, although the functionality of this putative protein is unknown. Despite this duplication, no recombination events recombination events were detected among the sequenced isolates. The low genetic variation could hinder the detection of recombinants.This work was supported by the following grants: Programa de Ayudas de Investigación y Desarrollo (PAID-11-21) of the Universitat Politècnica de València; PID2021-125787OR-C33 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”; and PROMETEO project for excellence groups 2021/072 Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital (Generalitat Valenciana).Kheireddine, A. (2023). First report of Cucurbit Chlorotic Yellows Virus (CCYV) and Tomato Leaf Curl New Delhi Virus (ToLCNDV) in Algeria and Lack of Evidence for Seed Transmission of ToLCNDV in Melon and Pumpkin [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19684

    Numerical Prediction of Turbulent Diffusion Flames Formed by Cylindrical Tube Injector

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    This work summarizes numerical results for a diffusion flame formed from a cylindrical tube fuel injector, issuing gaseous fuel jet vertically in a quiescent atmosphere. Both pure fuels as well as fuel mixtures are examined. The primary objective is to predict the flame base height as a function of the jet velocity. A finite volume scheme is used to discretize the time-averaged Navier-Stokes equations for the reacting flow, resulting from the turbulent fuel jet motion. The turbulent stresses, and heat and mass fluxes are computed from the Reynolds stress turbulence model. A chemical kinetics model involving a two-step chemical reaction mechanism is employed for the oxidation of methane. The reaction rate is determined from a procedure which computes at each point the minimum (process limiting) rate from an Arrhenius (kinetically controlled) expression and the eddy dissipation (turbulent mixing controlled) model. The Reynolds stress model (RSM), in conjunction with the two-step kinetics and the eddy dissipation model, produces flame base height and other flame characteristics that are in good agreement with experimental results. Numerical results are also in agreement with the hypothesis of Vanquickenborne and van Tiggelen concerning the stabilization mechanism of lifted diffusion flames. Furthermore, computed results also indicate that the flame base location can be approximately located by consideration of the turbulent mixing of the fuel jet in the non-reacting case. For propane, numerical results, obtained using one-step kinetics, show good agreement with the experimental data. Results pertaining to a methane-hydrogen mixture are obtained by using the RSM with three-step kinetics and the eddy dissipation model. The results for pure fuels and fuel mixtures indicate that the lift-off height for all the fuels considered in this study increases linearly with respect to the jet exit velocity. The study also analyzes the effect of swirling motion on the flame stabilization characteristics of the methane jet. The characteristics of methane flame are also determined by another combustion model which employs the probability density function (PDF) in conjunction with the flame sheet model. Results from this model differ in the near field from those predicted from the RSM-eddy dissipation model. However, in the far field the two combustion models yielded results that are in good agreement

    Characterization and modeling the effect of temperature on power HBTs InGaP/GaAs

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    The variation and stability of HBT’s parameters at different temperatures are important for utilizing these devices in high-power integrated circuits. The temperature dependence of the DC current gain of bipolar transistors, as a key device parameter, has been extensively investigated. A major issue of the power HBT’s is that the current gain is decreased with junction temperature due to self-heating effect. Hence, how to stabilize the DC current gain and RF performances is important issue to develop the power HBTs. This work describes the DC and high-frequency temperature dependence of InGaP/GaAs HBT’s. The substrate temperature (T) was varied from 25 to 150°C. The static and dynamic performances of the HBT are degraded at high temperature, due to the reduced of carrier mobility with increasing temperature. The current gain (β) decreases at high temperatures; from 140 to 127 at 25 to 150°C, while the decreases in the peak Ft and Fmax are observed from about 110 GHz to 68 GHz and from 165 GHz to 53 GHz respectively in the temperature range of 25 to 150°C

    Kalman Filter in Control and Modeling

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    Multi-Layered Optimal Navigation System For Quadrotors UAV

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    Purpose This paper aims to propose a new multi-layered optimal navigation system that jointly optimizes the energy consumption, improves the robustness and raises the performance of a quadrotor unmanned aerial vehicle (UAV). Design/methodology/approach The proposed system is designed as a multi-layered system. First, the control architecture layer links the input and the output spaces via quaternion-based differential flatness equations. Then, the trajectory generation layer determines the optimal reference path and avoids obstacles to secure the UAV from collisions. Finally, the control layer allows the quadrotor to track the generated path and guarantees the stability using a double loop non-linear optimal backstepping controller (OBS). Findings All the obtained results are confirmed using several scenarios in different situations to prove the accuracy, energy optimization and the robustness of the designed system. Practical implications The proposed controllers are easily implementable on-board and are computationally efficient. Originality/value The originality of this research is the design of a multi-layered optimal navigation system for quadrotor UAV. The proposed control architecture presents a direct relation between the states and their derivatives, which then simplifies the trajectory generation problem. Furthermore, the derived differentially flat equations allow optimization to occur within the output space as opposed to the control space. This is beneficial because constraints such as obstacle avoidance occur in the output space; hence, the computation time for constraint handling is reduced. For the OBS, the novelty is that all controller parameters are derived using the multi-objective genetic algorithm (MO-GA) that optimizes all the quadrotor state’s cost functions jointly

    Interval Valued Fuzzy Modeling and Indirect Adaptive Control of Quadrotor

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    In this paper, a combination of fuzzy clustering estimation and sliding mode control is used to control a quadrotor system, whose mathematical model is complex and has unknown elements, including structure, parameters, and so on. In addition, they may be affected by external environmental disturbances. At first, the nonlinear unknown part of the system is estimated by a fuzzy model, A new method is presented for constructing a Takagi-Sugeno (TS) interval-valued fuzzy model (IVFM) based on inputoutput data of the identified system. Following the construction of the fuzzy model that estimates the unknown part of the quadrotor system, a control and on-line adjusting of the fuzzy modeled part of dynamics is used. In this step, the system model will be estimated in adaptive form so that the dynamic equations can be used in sliding mode control. Finally, the proposed technique is applied, and the simulation results are presented to show the effectiveness of this approach in controlling the quadrotor with unknown nonlinear dynamics.Comment: 25 page

    Dr. Srećko Marač (1921-1985) : liječnik- psihijatar/psihoterapeut i pjesnik

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    Srećko Marač (Sušak, 1921. – Zagreb, 1990.). Nakon završetka sušačke gimnazije studira medicinu u Zagrebu i Padovi. Tijekom Drugoga svjetskog rata prekida studij i odlazi u NOR. Nakon rata završava studij u Zagrebu. Kao vojni liječnik radi u Bjelovaru i u Vojnoj bolnici u Zagrebu. Specijalizira psihijatriju i radi kao psihoterapeut u nekadašnjem Centru za mentalno zdravlje u Zagrebu.Godine 1973. objavljuje u vlastitom izdanju prvu zbirku pjesama – vlastiti izbor iz dugogodišnjeg rada – pod naslovom "Pjesme". Cilj je ovoga rada napisati cjelovitiji osvrt na tu zbirku pjesama izdanu 1973. po vlastitom izboru i nakladi. Gledalo se analizirati strukturu/kompoziciju zbirke, sadržaje, ugođaj i komunikativnost pojedinih njezinih dijelova. Kompozicijski je zbirka strukturirana u pet dijelova: Ad tyrannos, Iz partizana, Lutanja/traženja/snovi…, Satire i kušanja humora, More/brda i domovina. Umjesto zaključka valjalo bi se potruditi da ovaj liječnik-pjesnik, poeta neprijeporne književne ljepote i osoba puna ljudske dobrote, ne bude zaboravljen

    A Fully Autonomous Search and Rescue System Using Quadrotor UAV

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    In order to deal with critical missions a growing interest has been shown to the UAVs design. Flying robots are now used fire protection, surveillance and search & rescue (SAR) operations. In this paper, a fully autonomous system for SAR operations using quadrotor UAV is designed. In order to scan the damaged area, speeds up the searching process and detect any possible survivals a new search strategy that combines the standard search strategies with the probability of detection is developed. Furthermore the autopilot is designed using an optimal backstepping controller and this enables the tracking of the reference path with high accuracy and maximizes the flying time. Finally a comparison between the applied strategies is made using a study case of survivals search operation. The obtained results confirmed the efficiency of the designed system
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