Alkali activation of fly ashes part II: Mechanochemical pre-processing as way to optimize the reactivity

Good quality fly ash is in demand in the cement and concrete industries due to its ability to replace clinker Portland in blended cements and Portland cements in concrete. In this paper the authors show how by mechanochemical activation of fly ashes it is possible to increase the amount of fly ashes added to cement and concrete. The objective pursued in this study was to determine the mechanical properties and mineralogical characteristics of some mortars and concretes containing a high percentage of fly ash additions (50%): A= original fly ash; B= mechanically activated fly ash, C= mechanochemically activated fly ash. The mechanical strength of mortars prisms (4x4x16cm) were determined at early and long ages (1, 2, 7, 28, 90 and 180 days) at room temperature; also some concrete cubes (15x15x15cm) were analysed. The setting time and the heat flow released in the hydration process were additionally determined

Current knowledge of geopolymers and AAMs network

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Pixel Features for Self-organizing Map Based Detection of Foreground Objects in Dynamic Environments

Among current foreground detection algorithms for video sequences, methods based on self-organizing maps are obtaining a greater relevance. In this work we propose a probabilistic self-organising map based model, which uses a uniform distribution to represent the foreground. A suitable set of characteristic pixel features is chosen to train the probabilistic model. Our approach has been compared to some competing methods on a test set of benchmark videos, with favorable results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sustentabilidad de fincas productoras de mango Kent (Mangifera indica L.) en el valle de Yaután, provincia de Casma, Ancash, Perú

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Doctorado en Agricultura SustentableEl valle de Yaután alberga la mayor cantidad de productores (1,605) de mango “Kent” en la provincia de Casma, la cual se constituye una de las principales zonas productoras de mango de exportación a nivel nacional. Los objetivos de la investigación fueron identificar lasprincipales enfermedades poscosecha del mango, así como caracterizar los predios y productores, y evaluar la sustentabilidad de los predios productores de mango “Kent” en el valle y distrito de Yaután. Se realizaron visitas a predios de mango, observándose y estimándose daños a la fruta cosechada, además se tomaron muestras de frutos para análisis fitopatológicos, y de suelo para análisis nematológicos y de caracterización de la fertilidad; además se realizaron encuestas estructuradas a 139 productores para obtener información en el ámbito social, económico y ambiental. La mosca de la fruta, los daños de trips y oidiosis en floración y fructificación expresados a la cosecha, las queresas y cochinillas, así como la “lenticelosis” de frutos, constituyeron los principales problemas sanitarios. El análisis de la dimensión social muestra predominantemente hombres propietarios titulados de sus predios, con educación secundaria completa, mayores de 50 años, con casa propia, hecha de adobe ubicada generalmente en el mismo predio y con principales servicios básicos de agua y luzdisponibles, además acceden principalmente a servicios médicos en el pueblo de Yaután. El análisis de la dimensión económica muestra generalmente predios menores a 2.5 hectáreas, sembrándose varios cultivos además de mango. La edad de plantación predomina entre los 11 a 15 años, con rendimientos promedios de 11,543 Kg./ha. y costos productivos de S/. 5,261 /ha. El análisis ambiental muestra otras variedades de mango (Edward, Haden, Criollo, etc.) siendo la variedad “Kent” sembrada por todos y la de mayor área en los predios. El riego es principalmente gravedad, y la principal preocupación del productor son las plagasy enfermedades expresado en el elevado costo y número de fumigaciones realizadas en floración, crecimiento de frutos y previo a la cosecha. Los indicadores de sustentabilidadeconómico y social muestran valores mayores a 2 siendo sustentables, mientras que el indicador ambiental muestra valores menores a 2 siendo no sustentables el indicador y los predios productores de mango. Finalmente, las plagas y enfermedades expresados a la cosecha afectan notablemente el rendimiento exportable, siendo el punto crítico a resolver para lograr un mejor acceso al mercado de exportación.Yaután Valley is home to the largest number of "Kent" mango producers (1,605) in Casma province, which is one of the main mango-producing regions for export at the national level. The aim of research were to identify the main post-harvest diseases of mango, characterize the farms and producers, and evaluate the sustainability of the "Kent" mango-producing farms in Yaután valley and district. Visits to mango farms were conducted, with observations and estimations of damage to the harvested fruit. Fruit samples were also taken for phytopathological analysis, as well as soil samples for nematological analysis and fertility characterization. Additionally, structured surveys were conducted with 139 producers to gather information on social, economic, and environmental aspects. Fruit flies, damage from thrips and powdery mildew during flowering and fruiting leading to harvest, scales and mealybugs, as well as "lenticelosis" in fruits, were the main health problems on fruits. The analysis of social dimension predominantly showed male landowners with full secondary education, over 50 years old, owning their own adobe houses generally located on the same property, and having access to basic services like water and electricity. They mainly access medical services in Yaután town. The economic dimension analysis generally revealed farms smaller than 2.5 hectares, with various crops planted alongside mango. The predominant age of mango trees ranged from 11 to 15 years, with average yields of 11,543 kg/ha and production costs of S/ 5,261/ha. The environmental analysis showed the presence of other mango varieties (Edward, Haden, Criollo, etc.), with "Kent" being the variety planted by everyone and occupying the largest area in the farms. Gravity irrigation was the most common method, and the main concern of the producers was pests and diseases, which resulted in high costs and the need for numerous pesticide applications during flowering, fruit growth, and pre-harvest. Economic and social sustainability indicators showed values greater than 2, indicating sustainability, while the environmental indicator showed values less than 2, making environmental indicator and the farms producing Kent mangoes were not sustainable. Finally, pests and diseases at harvest significantly affected exportable yields, posing a critical issue that needs to be addressed to gain better access to the export market

Reproducción de Meloidogyne incognita (Kofoid & White) Chitwood en siete variedades de quinua (Chenopodium quinoa Willd.) en invernadero

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en FitopatologíaSiete variedades de Quinua: Salcedo Inia, Kanccolla, Choclito, Ccoitu Negra, Rosado de Huancayo, Blanca de Hualhuas y Pasankalla fueron sembradas en suelo estéril e inoculadas con dos densidades poblacionales iniciales (Pi) de Meloidogyne incognita (10 y 20 individuos por gramo de suelo), con el objetivo de evaluar la reproducción del nematodo y su efecto en el crecimiento de planta. La primera evaluación a los 30 días de inoculado, mostró pocos y pequeños nódulos, no encontrándose efectos en la altura y peso fresco de planta, pero si un mayor crecimiento del peso radicular al ser estimulado por la presencia del nematodo. En la segunda y tercera evaluación a los 60 y 90 días respectivamente, el peso fresco, peso seco y altura de planta de Quinua, no se relacionan directa ni indirectamente con las densidades poblacionales inoculadas (10 y 20 individuos por gramo de suelo), mientras que el tomate, sembrado como planta susceptible referencial, si se encontró una relación de, a menor peso o altura le corresponde una mayor población inoculada. Se reitera la presencia de nódulos en quinua, obteniéndose grados 3 y 4 según la escala del PIM (Proyecto Internacional de Meloidogyne), y grados 3,4,5 y 6 según la escala grafica de ZECK. El tomate susceptible referencial, muestra niveles de nodulación 5 y 8 para las respectivas escalas. A los 60 y 90 días, la población final (Pf) de Meloidogyne incognita disminuye en quinua, de 10 y 20 individuos por gramo de suelo (Pi) a menos de 5 (Pf). La tasa de reproducción (Pf/Pi) en todas las variedades de quinua es inferior a 0.45, considerándose a un HOSPEDANTE NO EFICIENTE. Finalmente, al no encontrar daño significativo en la biomasa aérea y considerándose un hospedante no eficiente, el comportamiento de todas las variedades de quinua ensayadas será de VARIEDADES RESISTENTES.Seven quinoa (Chenopodium quinoa) varieties: Salcedo Inia, Kanccolla, Choclito, Ccoitu Negra, Rosada de Huancayo, Blanca de Hualhuas and Pasankalla were sown in pots containing sterile substrate composed of river sand and agricultural soil (50/50), and they were inoculated with two initial population densities (Pi) of Meloidogyne incognita (10 and 20 infective juveniles per gram of soil), with the aim to evaluate the reproduction of the nematode and its effect on plant growth. The first evaluation, in day 30 after inoculation, showed in all varieties no effects on height and fresh weight of the plants, a few and small root knots and a higher weight of roots. During the second and third evaluation, in 60 and 90 days after inoculation, respectively, the height, fresh weight and dry weight of the plants were not directly or indirectly related to the population densities, while in susceptible tomato plants, used as reference, there was an indirect relationship: a lower weight or height in quinoa, corresponded to a greater inoculated population. Root knots in quinoa was repeated, obtaining level 3 and 4 according to PIM scale (International Project of Meloidogyne), and levels 3,4,5 and 6 according to ZECK graphic scale. Tomato susceptible plants had levels 5 and 8 of roots knots for each of the scales, respectively. At 60 and 90 days, final p opulation (Pf) of Meloidogyne incognita decreased in quinoa, from 10 and 20 individuals per gram of soil (Pi) to less than 5 (Pf), while reproduction rate (Pf / Pi) was less than 0.45, thus quinoa is a non- efficient host for Meloidogyne incognita. Finally, since no significant damage was found in the aerial biomass of quinoa and considering it to be a non-efficient host, the behavior of all tested quinoa varieties is going to be considered as Resistant Varieties.Tesi

Tratamiento

Los objetivos del tratamiento del paciente con EPOC son: aliviar los síntomas, mejorar la calidad de vida, la tolerancia al ejercicio, evitar la progresión de la enfermedad, prevenir las complicaciones y aumentar la supervivencia. Los principales pilares de este tratamiento son: evitar la exposición a factores de riesgo (tabaco, tóxicos ambientales...), el tratamiento broncodilatador y antiinflamatorio, la oxigenoterapia, la rehabilitación y algunas medias generales orientadas a mejorar la calidad de vida y la prevención de reagudizaciones. De todas ellas, únicamente el abandono del tabaquismo y la oxigenoterapia, en los casos indicados, han demostrado aumentar la expectativa de vida de los pacientes

New cementitious materials based on alkali-activated fly ash: performance at high temperatures

This paper reports on a comparative study of the mechanical performance at different temperatures of a commercial Portland cement, used as a control, and a new cementitious material made from an 8M-NaOH activated fly ash and containing no OPC. Two types of mechanical tests were conducted: (i) high temperature mechanical tests, to determine the strength and fracture toughness of the two materials between 251 and 6001C, and (ii) post-thermal treatment tests, to evaluate the residual strength after 1 h of exposure to different temperatures (2001, 4001, 6001, 8001, and 10001C). In both cases, the results showed that the new cementitious material performed significantly better at high temperatures than the Portland cement control. Differential thermogravimetry (DTG)/TG, Fourier transform infrared (FTIR), and X-ray diffraction analyses were also conducted to analyze the mineralogical and microstructural variations taking place in the material as a result of high temperature exposure. The results of these tests were correlated with the mechanical behaviour observed