1,808 research outputs found
Marchitez por Fusarium oxysporum Schlthl en masaguaro (Pseudosamanea guachapele) (Kunth).
Wilting by Fusarium oxysporum Schlthl in masaguaro (Pseudosamanea guachapele) (Kunth).Introducción: El masaguaro (Pseudomanea Guachapele) fue utilizado en la reforestación por la ”Fundación Orinoquia Biodiversa” en Arauca y presentó un marchitamiento desconocido.Objetivo. Caracterizar la enfermedad y su agente causal, y evaluar el posible control químico y biológico de la enfermedad.Metodología: La investigación se realizó en el barrio Campo Alegre Arauquita, Arauca, Colombia. Las muestras se analizaron en el laboratorio de microbiología de la Universidad de Pamplona. Se caracterizó la enfermedad y su agente causal, se determinó la incidencia y severidad de la enfermedad y se estimaron las pérdidas monetarias considerando las plantas muertas. Se realizó un experimento de control de marchitez utilizando benomyl y Bacillus subtilis, comparándolos con un control sin tratamiento. Resultados: Fusarium oxysporum fue identificado como agente causal de la enfermedad. El marchitamiento alcanzó entre el 13 y el 54% de incidencia. Las pérdidas económicas se estimaron en más de 19 millones de pesos / ha. Conclusión: Se verificó la acción preventiva y erradicativa de benomyl y solo acción preventiva de B. subtilis
A systematic literature review on the semi-automatic configuration of extended product lines
Product line engineering has become essential in mass customisation given its ability to reduce production costs and time to market, and to improve product quality and customer satisfaction. In product line literature, mass customisation is known as product configuration. Currently, there are multiple heterogeneous contributions in the product line configuration domain. However, a secondary study that shows an overview of the progress, trends, and gaps faced by researchers in this domain is still missing. In this context, we provide a comprehensive systematic literature review to discover which approaches exist to support the configuration process of extended product lines and how these approaches perform in practice. Extend product lines consider non-functional properties in the product line modelling. We compare and classify a total of 66 primary studies from 2000 to 2016. Mainly, we give an in-depth view of techniques used by each work, how these techniques are evaluated and their main shortcomings. As main results, our review identified (i) the need to improve the quality of the evaluation of existing approaches, (ii) a lack of hybrid solutions to support multiple configuration constraints, and (iii) a need to improve scalability and performance conditions
Influence of La3+ on the microestructure of bismuth titanate solid solutions
[ES] En este trabajo se reporta la síntesis de la serie de soluciones sólidas de titanato de bismuto, Bi4Ti3O12 con La3+ por coprecipitación
de los respectivos hidróxidos. Las soluciones sólidas se caracterizaron por difracción de rayos-X y medidas de densidad.
Por técnicas de SEM se determinó la influencia del La3+ en la microestructura del titanato de bismuto puro. En este estudio
se prepararon diversas composiciones de la solución sólida a y se sinterizaron a 850ºC. Los resultados se presentan en
función de la concentración del dopante.[EN] In this work a solid solution of bismuth titanate Bi4Ti3O12 with La3+ is synthesised by coprecipitation of their hydroxides. The
solid solutions were characterised by X-ray powder diffraction and density measurements. By SEM the influence of La3+ in
bismuth titanate was analised. In this study several compositions of the solid solution were prepared and sintered at 850ºC.
The results are presented as a function of the dopant concentration.Los autores agradecen el apoyo de los proyectos PAPIIT,
DGAPA, UNAM No. IN102700 y CONACYT No. 33361-U.Peer reviewe
Vibrational characterictics of asymmetric metal-ceramic piezocomposites
[ES] Se han estudiado las características mecánico-vibracionales de piezocomposites metal-cerámica asimétricos. Kovar-PZT. Para
esta caracterización se utilizó la técnica de vibrometría láser mediante la cual se obtienen perfiles de amplitud a diferentes frecuencias
para el piezocomposite. Se muestran los modos diferenciados de vibración en el intervalo de 2 Hz a 20 kHz y se discuten
los resultados en la perspectiva de optimizar el diseño de los dispositivos.[EN] The mechanical and vibrational characteristics of asymmetric metal-ceramic piezocomposites, Kovar-PZT, have heen studied.
For this characterization a laser vibrometry technique was used to obtain amplitude profiles of vibration at different frequencies
for the piezocomposite. The vibration spectra showed modes in the range 2 Hz to 20 kHz. The results were discussed in
the framework of design optimization.Los autores agradecen el apoyo financiero para la realización
de esta investigación a la Universidad Nacional Autónoma de
México, Consejo Nacional de Ciencia y Tecnología de México,
Comisión Internacional de Ciencia y Tecnología de España y
Programa para la Cooperación y el Desarrollo a través de los
proyectos PAPIIT-IN106998, CONACYT-27624U, CICYT
MAT97-694-C02-01 y CYTED Red VIII.F.Peer reviewe
Intrahepatic injection of recombinant adeno-associated virus serotype 2 overcomes gender-related differences in liver transduction
The liver is an attractive organ for gene therapy because of its important role in many inherited and acquired diseases. Recombinant adeno-associated viruses (rAAVs) have been shown to be good candidates for liver gene delivery, leading to long-term gene expression. We evaluated the influence of the route of administration on rAAV-mediated liver transduction by comparing levels of luciferase expression in the livers of male and female mice after injection of rAAV serotype 2, using three different routes of administration: intravenous (IV), intraportal (IP), or direct intrahepatic (IH) injection. To determine transgene expression we used a noninvasive optical bioluminescence imaging system that allowed long-term in vivo analysis. After IV injection dramatic differences in liver transgene expression were observed, depending on gender. When IP injection was used the differences were reduced although they were still significant. Interestingly, direct intrahepatic injection of rAAV vectors was associated with the fastest and strongest onset of luciferase expression. Moreover, no gender differences in liver transduction were observed and luciferase expression was confined to the site of injection. Thus, direct intrahepatic injection of rAAV offers specific advantages, which support the potential of this route of administration for future clinical applications
Simulador de negocios CAPSIM: la industria de sensores y las estrategias de la empresa Chester
En este documento se reportan las especificaciones técnicas, decisiones, análisis y aprendizajes obtenidos en el simulador de negocios CAPSTONE. Se explica el entorno de competencia, las estrategias genéricas y se establece el perfil de la empresa Chester. Se define la identidad corporativa, los objetivos, la estrategia a seguir durante la competencia, así como los potenciales ajustes. Se explica lo ocurrido en cada uno de los periodos de competencia, desde el panorama general, las decisiones de producción, investigación y desarrollo, finanzas y mercadotecnia de cada una de las empresas, así como un análisis de los resultados y descripción de los errores, aciertos y ajustes a realizar
Active Disturbance Rejection Control for Robot Manipulator
Active Disturbance Rejection Control (ADRC) is a control methodology used in chemical processes, aircraft, motors, and other systems. This paper compares the results of an ADRC controller to a Proportional Integral Derivative controller (PID), applied to two degrees of freedom robots. A Linear Extended State Observer (LESO) is used to reconstruct the state variables and unknown parameters needed to control the position of each link. The ADRC can achieve the tracking position and estimate the velocity of each link. The results of the simulation program are shown
Effect of ripening on physico-chemical properties and bioactive compounds in papaya pulp, skin and seeds
Byproducts generated by the food industry represent an alternative to obtain functional ingredients. Byproducts of tropical fruits, such as papaya skin and seeds, represent a source of bioactive compounds (BC), which could change during fruit ripening. Effect of ripening stage (RS) on BC content and antioxidant properties of edible pulp, skin and seeds of papaya cv. Maradol was determined. Papaya skin showed significantly higher ascorbic acid (~250 mg AAE/100 g) content than seeds (~20 mg/100 g), while pulp had the highest values (~600 mg/100 g). However, papaya skin presented higher total phenolic content (~560 mg GAE/100 g) and flavonoids (~1000 mg QE/100 g) than pulp and seeds. Also, papaya skin showed the highest values followed by pulp and seeds with TEAC, FRAP and DPPH. Papaya skin had higher carotenoids and α-tocopherol (~1500 µg/100 g and ~4000 µg/100 g, respectively) content than pulp and seeds. BC content in each byproduct varied in all RS. Therefore, among the papaya byproducts, skin represents a good source of BC with good antioxidant properties, which may be used to extract them for its incorporation in functional foods depending on RS
Morphological, Electrical, and Chemical Characteristics of Poly(sodium 4-styrenesulfonate) Coated PVDF Ultrafiltration Membranes after Plasma Treatment
A commercial ultrafiltration (UF) membrane (HFM-183 de Koch Membrane Systems) made of poly(vinylidene fluoride) (PVDF), was recovered with a negatively-charged polyelectrolyte (poly(sodium 4-styrenesulfonate)) (PSS), and the effects on its electric, chemical, and morphological properties were analyzed. Atomic force microscopy (AFM), liquid-liquid displacement porometry, Electrical Impedance Spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to investigate the modifications induced by the deposition of PSS on the PVDF positively-charged membrane and after its treatment by a radio frequency Ar-plasma. These techniques confirmed a real deposition and posterior compaction of PSS with increasing roughness and decreasing pore sizes. The evolution of the electric resistances of the membranes confirmed crosslinking and compaction with shielding of the sulfonated groups from PSS. In this way, a membrane with a negatively-charged active layer and a pore size which was 60% lower than the original membrane was obtained. The composition of the additive used by manufacturers to modify PVDF to make it positively charged was obtained by different procedures, all of which depended upon the results of X-ray photoelectron spectroscopy, leading to fairly consistent results. This polymer, carrying positive charges, contains quaternary nitrogen, as confirmed by XPS. Moreover, Raman spectroscopy confirmed that PVDF changes from mostly the β to the α phase, which is more stable as a substrate for the deposited PSS. The aim of the tested modifications was to increase the retention of divalent anions without reducing permeability.Fil: Sandoval Olvera, Ivette G.. Universidad de Guanajuato; MéxicoFil: González Muñoz, Pilar. Universidad de Guanajuato; MéxicoFil: Diaz, Dario Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Maroto Valiente, Ángel. Universidad de Guanajuato; MéxicoFil: Ochoa, Nelio Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Carmona, Francisco J.. Universidad de Extremadura; EspañaFil: Palacio, Laura. Universidad de Valladolid. Facultad de Ciencias; EspañaFil: Calvo, José I.. Universidad de Valladolid. Facultad de Ciencias; EspañaFil: Hernández, Antonio. Universidad de Valladolid. Facultad de Ciencias; EspañaFil: Ávila Rodríguez, Mario. Universidad de Guanajuato; MéxicoFil: Prádanos, Pedro. Universidad de Valladolid. Facultad de Ciencias; Españ
Geometria konplexuko pieza baten mekanizazio-estrategiak CAM bidez
In this work, knee prosthesis manufacturing process using CO2 cooling is described. It is necessary to use 5 continuous axis milling in order to manufacture this complex geometry. However, surfaces complexity and material (titanium) low machinability characteristics present a challenge for manufacturers. In this case, process operations and machining parameters for this component manufacturing are specified. Besides, virtual verification of machining process is also performed in order to avoid collisions. Moreover, cooling is a key factor in this case regarding medical components cleaning specifications. Traditional coolants are replaced by CO2 cooling.; Honako lan honetan belaun-protesiko osagarrien fabrikazioa azaltzen da CO2 hozgarri kriogenikoa erabiliz. Osagarrien konplexutasuna dela eta, beharrezkoa da 5-ardatzen interpolazioa gauzatzea fresaketa-eragiketetan. Gainazalen konplexutasun horrek eta materialaren (titanioaren) mekanizagarritasun baxuak mekanizazio-erronka berriak sortzen dituzte. Kasu honetan, osagarrien fabrikaziorako erabilitako mekanizazio-estrategiak eta mekanizazio-aldagaiak deskribatzen dira. Gainera, mekanizazioan ager daitezkeen talkak saihesteko, egiaztatze birtuala erabili da. Horrez gain, hozketa faktore garrantzitsu bat da osagai medikoen garbitasuneko beharrizanei dagokienez. Ohiko hozte-teknikak CO2 hozgarri kriogenikoarekin ordeztu dira
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