Summary: In aquaponics, the use of substrate allows the colonization of nitrifying bacteria and may act as a biofilter. The diameter of substrate particles can be decisive in the colonization of substrate by bacteria and can affect the development and yield of plants. Thus, in this research, we raised the hypothesis that the particle diameter of tezontle affects the development and yield of plants, as well as the bacterial colonization of substrate. The experiment consisted of 12 fish ponds of 120 L,12 tubs of 240 L for the substrate and a pump as auxiliary oxygenation for the fish ponds. Three crops were established in each tub: tomato, cucumber, and lettuce. The crops seedlings were transplanted into three tezontle granulometries: <1 cm, >5 cm and a 50:50 mix of both sizes with three replications per treatment. An analysis of variance and a Tukey's test were performed. There was no effect of substrate particle diameter on the height, stem diameter and SPAD readings in tomato, cucumber, and lettuce plants. In addition, the particle diameter of the substrate did not affect the yield, firmness, titratable acidity, or Brix degrees in the tomato fruits. Furthermore, there was no effect on the yield and quality of cucumber fruits. In contrast, for lettuce, the fresh weight of the substrate consisting of particles <1 cm in diameter was 55% higher than that of particles >5 cm in diameter (89.87 and 50.12 g per plant, respectively). The particle diameter does not affect the yield or quality of the established crops, however, in practical terms, the tezontle particles <1 cm in diameter are recommended due to their greater moisture retention capacity and higher surface area for bacteria colonization.

Resumen: En la acuaponía el uso de sustrato permite la colonización de bacterias nitrificantes y actúa como biofiltro. El diámetro de partículas del sustrato puede ser determinante en la colonización del sustrato por las bacterias y puede afectar el desarrollo y rendimiento de las plantas; razón por la que en esta investigación se planteó la hipótesis de que tamaño de partícula del tezontle afecta la colonización de bacterias y el desarrollo y crecimiento de las plantas. El experimento consistió de recipientes de 120 L como estanques para los peces, y de 12 tinas de 240 L para el sustrato y una bomba para oxigenación auxiliar a los estanques de los peces. Se establecieron 3 cultivos en cada tina: tomate, pepino y lechuga. Estos cultivos fueron trasplantados en 3 granulometrías de tezontle: diámetro menor a 1 cm, mayor a 5 cm y mezcla 50:50% de ambos tamaños con tres repeticiones por tratamiento. Se realizó un análisis de la varianza y prueba de Tukey. No hubo efecto del diámetro de partícula del sustrato en la altura, diámetro de tallo y lecturas SPAD en las plantas de tomate, pepino y lechuga. El diámetro de partícula del sustrato no afectó el rendimiento ni firmeza, acidez titulable y grados Brix en los frutos de tomate. Tampoco hubo efecto sobre rendimiento y de calidad de frutos de pepino. En lechuga el peso fresco correspondiente al sustrato con partículas menores a 1 cm fue 55% mayor al de partículas mayores a 5 cm: 89.87 y 50.12 g por planta, respectivamente. El diámetro de partícula no afecta el rendimiento ni la calidad de los cultivos establecidos, sin embargo, en términos prácticos el tezontle fino menor a un cm es recomendable porque tiene mayor capacidad retención de humedad y mayor superficie para que las bacterias colonicen el medio.

Summary: A retrospective-prospective research was carried out to establish a soil quality index (SQI) of Los Rios region (RR), Tabasco, Mexico, and its modeling with the near infrared technology (NIR) and chemometrics. The SQI was determined with the OM / (clay + silt) relationship to evaluate the Cambisol soils of RR. The OM percentage and the SQI were compared to define the best soil quality qualifier. Based on the SQI, 58% of the soils in RR exhibit degradation, while only 14% indicates a low concentration of OM. Therefore, we conclude that the SQI is more sensitive to quantify soil degradation compared to the evaluation based on OM. A sustainable soil management program and soil practices adapted to local environmental, social and economic conditions are recommended to increase OM and improve SQI. With the SQI, a classification model was established using near-infrared spectroscopy and chemometrics. The spectra of each soil sample were recorded and through chemometric interpretation, it was shown that it is possible to conduct a partial least squares discriminant analysis model (PLS-DA) to predict the SQI. The model meets all statistical qualifiers and correctly predicts the SQI in 100% of cases. We conclude that the NIR technology provides sufficient information to predict the SQI with the advantage of eliminating the consumption of reagents, no laboratory waste is generated, the analysis time is reduced to minutes, and the sample under study is not destroyed. In addition, the procedure is simple as it consists of drying, grinding and sieving the soil samples to assess the structural quality of the soil.

Resumen: Se realizó una investigación retrospectiva - prospectiva, para establecer un índice de calidad de los suelos (ICS) de la región de los Ríos (RR) en Tabasco, México y su modelación con la tecnología de infrarrojo cercano (NIR) y la quimiometría. Con la relación MO / (arcilla + limo) se estableció el ICS para evaluar los suelos Cambisoles de la RR. El porcentaje de MO y el ICS fueron comparados para definir el mejor calificador de la calidad de los suelos. Con base en el ICS, el 58% de los suelos de la RR presentan degradación, mientras que, solo el 14% de los suelos indican que presentan baja concentración de MO. Por lo que se concluye que el ICS es más sensible para cuantificar la degradación de los suelos cuando se comparó con la evaluación basada en la MO. Se recomienda un programa de manejo sostenible del suelo y prácticas edafológicas adaptadas a las condiciones locales, ambientales, sociales y económicas, para incrementar la MO y mejorar el ICS. Con el ICS se estableció un modelo de clasificación mediante espectroscopía de infrarrojo cercano y quimiometría. Se registraron los espectros de cada muestra de suelo y mediante interpretación quimiométrica se demostró que es posible establecer un modelo de análisis discriminante por mínimos cuadrados parciales (PLS-DA) para predecir el ICS. El modelo cumple con todos los calificadores estadísticos y predice correctamente el ICS en el 100% de los casos. Se concluye que la tecnología NIR genera información suficiente para predecir el ICS; con la ventaja de, eliminar el consumo de reactivos, no se generan residuos de laboratorio, se reduce el tiempo de análisis a minutos y no se destruye la muestra en estudio. Y solo se necesita secar, moler y tamizar las muestras de suelos para evaluar la calidad estructural de suelos.

Abstract. Marine mollusks provide important ecosystem services. They create habitats for benthic organisms, filter water, biodeposit organic carbon in the seafloor, and serve as food sources for other organisms. Studies of mollusk diversity require time-consuming methods to process samples and identify species. Thus, it is not surprising that most studies have focused on macromollusks that can be collected and processed easily, ignoring micromollusk species. Without understanding the ecology and distributions of micromollusks properly, it is impossible to assess their populations and implement adequate conservation measures. Here we present microgastropods collected in Bahia de los Angeles at the family level for September 2013 (summer) and February 2014 (winter). During each season, we sampled 6 coastal sediment stations, and analyzed depth, salinity, temperature, granulometry, and organic matter. A total of 20,353 specimens were collected: 15,310 in summer and 5,043 in winter. Seven micromollusk families were identified: Barleeidae, Caecidae, Cerithiidae, Eulimidae, Pyramidellidae, Rissoidae, and Tornidae. Caecidae and Barleeidae exhibited the highest densities among all families in summer and winter, respectively (278,044 ind·m-2, 142,222 ind·m-2). The lowest densities for summer and winter were observed for the Tornidae family (~1,867 ind·m-2, ~1,411 ind·m-2). Barleeidae, Caecidae, Cerithiidae, Rissoidae, and Tornidae were classified as herbivorous and detritivorous; Eulimidae and Pyramidellidae, as carnivorous and ectoparasitic. Tornidae and Eulimidae showed symbiotic relationships with various invertebrate species. The Bayesian analysis of variance indicated a high probability of differences only in summer (BF > 3). When comparing the stations in both periods, all stations, except station 6, showed differences between periods (BF > 3). The canonical correlation analysis indicated some associations between family abundances and temperature. This study provides valuable information that expands the knowledge of micromollusk biodiversity in the coastal area of Bahia de los Angeles, an important site for conservation in Mexico.

Resumen. Los moluscos marinos brindan importantes servicios ecosistémicos debido a que generan hábitats para organismos bentónicos, filtran agua, biodepositan carbono orgánico en el fondo marino y sirven como fuente de alimento para otros organismos. Los estudios de diversidad de moluscos requieren métodos de muestreo e identificación de especies muy tardados. Por lo tanto, no sorprende que la mayoría de los estudios se centren en los macromoluscos, los cuales son fácilmente recolectados y procesados, ignorando las especies de micromoluscos cuya identificación es difícil y tardada. Si no se comprende la ecología y distribución de los micromoluscos, es imposible evaluar sus poblaciones e implementar medidas de conservación. Aquí presentamos microgasterópodos recolectados en Bahía de los Ángeles a nivel de familia en 2 muestreos, en septiembre de 2013 (verano) y en febrero de 2014 (invierno). En cada temporada, muestreamos 6 estaciones costeras y realizamos mediciones de profundidad, salinidad, temperatura, granulometría y contenido de materia orgánica. Se recolectaron 20,353 ejemplares: 15,310 en verano y 5,043 en invierno. Se identificaron 7 familias: Barleeidae, Caecidae, Cerithiidae, Eulimidae, Pyramidellidae, Rissoidae y Tornidae. Caecidae y Barleeidae presentaron la máxima densidad en verano e invierno, respectivamente (278,044 ind·m-2, 142,222 ind·m-2). Tornidae presentó las densidades más bajas para verano e invierno (~1,867 ind·m-2, ~1,411 ind·m-2). Barleeidae, Caecidae, Cerithiidae, Rissoidae y Tornidae se clasificaron como herbívoros y detritívoros; Eulimidae y Pyramidellidae, como carnívoros y ectoparásitos. Tornidae y Eulimidae muestran relaciones simbióticas con varias especies de invertebrados. El análisis bayesiano indicó una alta probabilidad de diferencias para verano (BF > 3). Al comparar la misma estación entre muestreos, solo la estación 6 mostró diferencias entre periodos (BF > 3). Este estudio brinda información valiosa que amplía el conocimiento de la biodiversidad de micromoluscos en la zona costera de Bahía de los Ángeles, un importante sitio de conservación en México.

Abstract The process of temperate forest harvesting generates reversible impacts on the soil by altering its properties, mainly due to the reduction of vegetation, as well as to cutting and dragging of wood, which causes an increase in apparent density and reduces infiltration. The objective of this study was to evaluate the effect of different forest management practices on the physical-hydrological properties of the soil and their relationship with water infiltration in temperate forest soils. The study areas were: recently intervened area, with the intervention dating back 18 years, and conservation area (control) in a temperate pine-oak forest under exploitation in the state of Hidalgo. The variables evaluated were bulk density and porosity (methodology proposed by USDA), granulometry (Bouyoucos method), and infiltration tests with the double-ring method. The results for bulk density were higher in the recently intervened area (0.62 g cm-3) and lower in the conservation area (0.32 g cm-3). Porosity in the conserved area was 11 % higher than in the recently intervened area (88 and 77 %, respectively). The infiltration rate in the conserved area was 2.641 cm min-1 compared to 0.655 cm min-1 in the area intervened 18 years ago. The authors conclude that the bulk density of the soil increases, while the porosity and infiltration capacity decrease with the implementation of harvesting activities ―a situation that gradually recovers with the establishment of new forests.

Resumen El proceso de aprovechamiento del bosque templado genera impactos reversibles en el suelo al alterar sus propiedades, principalmente por la reducción de la vegetación, troceo y arrastre de la madera que ocasiona aumento en la densidad aparente y reduce la infiltración. El objetivo de este estudio fue evaluar el efecto de diferentes prácticas de manejo forestal sobre propiedades físico-hidrológicas del suelo y su relación con la infiltración del agua en los suelos de un bosque de clima templado. Las áreas de estudio fueron: área de reciente intervención, intervenida hace 18 años y área de conservación (testigo) en un bosque templado de pino-encino bajo aprovechamiento en el estado de Hidalgo. Las variables evaluadas fueron, densidad aparente y porosidad (metodología propuesta por USDA), granulometría (método de Bouyoucos) y pruebas de infiltración con el método de doble anillo. Los resultados de la densidad aparente fueron mayores en el área de reciente intervención (0.62 g cm-3) y menor en el área de conservación (0.32 g cm-3). La porosidad en el área conservada superó en 11 % al área de reciente intervención (88 y 77 %, respectivamente). La tasa de infiltración en el área conservada tuvo 2.641 cm min-1 en comparación con 0.655 cm min-1 del área intervenida hace 18 años. Se concluye que la densidad aparente del suelo se incrementa mientras que la porosidad y capacidad de infiltración disminuyen con la ejecución de las actividades de aprovechamiento, situación que se recupera en forma gradual con el establecimiento de los nuevos bosques.

Resumen Introducción. Tectona grandis es la especie con la mayor área plantada en Costa Rica, por los altos precios en el mercado internacional. La producción de plantas para reforestación se ha tecnificado en el país, se desarrolla basado en tecnologías de ambientes protegidos, que permiten aumentar la productividad, disminuir costos de operación y ofrecer material de siembra durante todo el año. Objetivo. Evaluar el efecto de dos sustratos y cinco densidades de siembra en la productividad de minijardines clonales de Tectona grandis dentro de un ambiente protegido. Materiales y métodos. Se caracterizaron mediante análisis de granulometría y retención de humedad, cuatro sustratos inertes de fácil adquisición, de ellos se seleccionó el polvo de piedra como óptimo. Se estableció un ensayo experimental con diseño factorial 2x5 en San Carlos, Costa Rica, para evaluar dos sustratos (polvo de piedra solo y con 25 % de carbón) y cinco densidades de siembra (cm) de 10x10, 10x5, 7x5, 10x10 con dos plantas por hoyo y 10x10 con una planta en el medio. Cada densidad tuvo cuatro clones como efecto repetición. El ensayo se evaluó durante cinco ciclos continuos de producción de enero a setiembre del 2021. Resultados. El uso del polvo de piedra sin carbón como sustrato, registró la mayor productividad a un menor costo. El arreglo espacial de siembra de 10x10 cm con una planta en el centro (n=145 plantas/m2), registró la mayor producción de brotes por planta madre (1,16). El arreglo 7x5 cm aumentó la productividad hasta en 206 brotes m2/mes. Conclusión. El cambio de densidad de siembra del minijardín clonal, en una primera etapa a 10x10 cm con una planta en el centro, resultó en alto impacto en productividad (74 %), mayor eficiencia en el uso del espacio y mejor gradualidad del cambio en el sistema operativo.

Abstract Introduction. Tectona grandis is the species with the largest planted area in Costa Rica, due to the high prices in the international market. The production of plants for reforestation has been technified in the country and is currently being developed based on protected environment technologies, which increase productivity, reduce operating costs, and offer planting material throughout the year. Objective. To evaluate the effect of two substrates and five planting densities on the productivity of clonal mini-gardens of Tectona grandis in a protected environment. Materials and methods. Four readily available inert substrates were characterized by granulometry and moisture retention analysis, from which stone dust was selected as the optimum substrate. An experimental trial with a 2x5 factorial design was established in San Carlos, Costa Rica to evaluate two substrates (stone dust alone and with 25 % charcoal) and five planting densities (cm) of 10x10, 10x5, 7x5, 10x10 with two plants per hole and 10x10 with one plant in the middle. Each density had four clones as a replicate effect. The trial was evaluated during five continuous production cycles from January to September 2021. Results. The use of stone dust as substrate, without charcoal, recorded the highest productivity at a lower cost. The spatial planting arrangement of 10x10 cm with one plant in the middle (n=145 plants/m2), recorded the highest shoot production per mother plant (1.16). The 7x5 cm arrangement increased productivity by up to 206 shoots m2/month. Conclusion. The change in planting density of the clonal mini-garden, in a first stage to 10x10cm with an additional plant in the center, resulted in a high impact on productivity (74 %), greater efficiency in the use of space, and a better gradual change in the operating system.

ABSTRACT Soil sampling is a fundamental stage for recommending agricultural correctives and fertilizers, estimating the nutritional demands of plants, and consequently maximizing productivity. Therefore, this study aimed to assess the performance of three soil samplers in different management systems in terms of sample quality and operational efficiency. A completely randomized experimental design was used in a factorial scheme. Three samplers and two sampling depths (3 × 2) were used with four replicates. At each sampling location, eight single samples were taken at a varying sampling depth of 0.0-0.2 and 0.2-0.4 m, and the collection time was recorded. Samples were analyzed for chemical attributes and granulometry. Statistically significant differences were observed for specific attributes (organic matter, K, Ca, CEC, pH, and S). In terms of operational efficiency, the hydraulic sampler was more efficient than the other samplers, being three times faster than the combustion drill and six times faster than the manual probe. Thus, it is suitable and reliable for soil sampling purposes.

RESUMO A amostragem de solo é uma etapa fundamental para a recomendação de corretivos e fertilizantes agrícolas, estimar demanda nutricional de plantas e consequentemente maximizar a produtividade. Por conseguinte, o objetivo deste estudo foi avaliar o desempenho de três amostradores de solo em áreas de diferentes sistemas de manejo no contexto de qualidade da amostra e eficiência operacional. Utilizou-se o delineamento experimental inteiramente casualizado em esquema fatorial 3 × 2 (três amostradores e duas profundidades de amostragem), com quatro repetições. Em cada ponto amostral, foram retiradas oito amostras simples em profundidade variável de coleta de 0,0-0,2 e 0,2-0,4 m, cronometrando-se o tempo de coleta. Foram avaliados atributos químicos e granulometria dos solos. Foram observadas diferenças estatísticas para atributos específicos (matéria orgânica, K, Ca, CEC, pH e S). Em termos de eficiência operacional, o amostrador hidráulico superou os demais amostradores, sendo três vezes mais rápido em comparação com o sistema a combustão e seis vezes em comparação com a sonda manual; sendo assim apto e recomendável para as operações de coleta de solo.

Resumen: El trabajo evaluó el rendimiento frente al comportamiento del agua de los morteros de revestimiento con la incorporación de caucho de neumáticos. Se utilizaron granulometrías de #0.60 mm y #1.19 mm, con niveles de incorporación de 10% y 20% (en volumen), reemplazando el agregado fino. La metodología consistió en pruebas de capilaridad; secado; procedimientos de humidificación y secado con control de masa, termografía infrarroja y medición de humedad. Los resultados indicaron que en capilaridad y secado, la dosificación A20F (granulometría #0.60 mm y 20% de incorporación) mostró una tasa de absorción reducida contribuyendo a la eliminación de agua. En el proceso de humidificación y secado, tanto activo como pasivo, posiblemente el caucho bloqueó los poros de la masa, ya que las dosificaciones con granulometría #0.60 mm (A10F y principalmente A20F) demostraron perder agua, lo que indica que la mayor parte del agua absorbida se concentraría en la superficie del compuesto.

Abstract: This paper evaluated the behavioural performance to coating mortar water with rubberized tyres. #0.60 mm and #1.19 mm grain sizes have been used with the incorporation of 10 and 20% (in volume), replacing the small units. The methodology has elapsed with capillary and drying tests; humidification and drying procedures with mass control, infrared thermography and measurement of humidity. The results indicated that in capillarity and drying the trace A20F (#0.60 mm particle size and incorporation of 20%) had have a low absorption rate and helped in the process of water disposal. In the humidification and drying process, both active as well as passive, the rubber possibly blocks the pores of mass, for the grain traits size #0.60 mm (A10F and primarily A20F) have proven easy to lose water, suggesting that the majority of water absorbed would be concentrated on the surface part of the composite.

Resumen Los desechos de toba volcánica son agregados pétreos generados por procesos de corte y tallado en los bancos de material, los cuales al sustituirse parcialmente en la granulometría de una mezcla asfáltica se convierten en agregados sustentables, así que la investigación presente tiene por objetivo reducir el uso de agregado pétreo basáltico en una mezcla asfáltica manteniendo los valores límite de estabilidad y flujo. Se realizó un diseño Marshall para evaluar la volumetría, la estabilidad y el flujo, realizándose 36 muestras (pastillas) al sustituir 0, 10 y 20 % de agregado pétreo basáltico por deshechos de toba volcánica. Los resultados mostraron que el contenido de vacíos de aire (VA) aumentó conforme se agregó más deshecho de toba volcánica, y el flujo disminuyó debido a que la toba volcánica tuvo mayor capacidad de absorción de asfalto en la granulometría con 10 y 20 % de deshechos de toba volcánica. Lo anterior, generó que la capa superficial de asfalto que recubre las partículas del agregado se adelgazara y el contacto entre ellas fuera mayor, por lo tanto, cuando la sustitución parcial fue de 10 %, la estabilidad aumentó respecto a la muestra de control (0 % de sustitución), en cambio, con 20 % comenzó a decrecer porque la resistencia a la abrasión de la toba fue de 28.26 %. Por último, se obtuvo que el contenido óptimo de asfalto para 0 % de sustitución fue de 4.55 %, para 10 % de sustitución de 4.63 % y para 20 % de sustitución de 4.83 %, esto reflejó que se requiere mayor contenido de asfalto cuando se agrega la sustitución parcial de desechos de toba volcánica, sin embargo, el aumento de asfalto de 0.08 y 0.28 % fue mínimo respecto al contenido óptimo de asfalto de la mezcla control. Por lo tanto, la sustitución parcial con desecho de toba volcánica con mejores resultados fue de 10 %, dicha sustitución generó mayor estabilidad y menor flujo respecto a la muestra de control, estos siendo resultados más favorables que solo haberlos mantenido igual que la muestra control como lo mencionaba el objetivo.

Abstract Volcanic tuff wastes are stone aggregates generated by cutting and carving processes in the material banks, which, when partially replaced in the granulometry of an asphalt mixture become sustainable aggregates, so the present research aims to reduce the use of basaltic stone aggregate in an asphalt mixture maintaining the limit values of stability and flow. A Marshall design was carried out to evaluate the volumetry, stability and flow, making 36 samples (pill) by substituting 0, 10 and 20 % of basaltic stone aggregate for volcanic tuff waste. The results showed that the content of air voids (VA) increased as more volcanic tuff waste was added, and the flow decreased because the volcanic tuff had a greater capacity to absorb asphalt in the granulometry with 10 and 20 % waste of volcanic tuff. The foregoing caused the surface layer of asphalt that covers the aggregate particles to become thinner and the contact between them to be greater, therefore, when the partial substitution was 10 %, the stability increased in comparison to the control sample (0 % substitution), on the other hand, with 20 % it began to decrease because the abrasion resistance of the tuff was 28.26 %. Finally, it was obtained that the optimum asphalt content for 0 % substitution was 4.55 %, for 10 % substitution 4.63 % and for 20 % substitution 4.83 %, this reflected that a higher asphalt content is required when adds the partial substitution of volcanic tuff waste, however, the asphalt increase of 0.08 and 0.28 % was minimal with respect to the optimal asphalt content of the control mix. Therefore, the partial substitution with volcanic tuff waste with better results was 10 %, this substitution generated greater stability and less flow with respect to the control sample, these being more favorable results than just keeping them the same as the control sample as mentioned by the objective.

Resumo O uso de polímeros na indústria está em expansão, principalmente o de polímeros reforçados com fibra de vidro (PRFV). Na produção de peças com PRFV, inevitavelmente, são geradas quantidades significativas de resíduos, que carecem de destino em aterros industriais, o que representa um custo para o setor industrial e um problema ambiental. A busca por soluções que possam incorporar esses resíduos no processo ou como substituinte de matérias-primas é um dos focos atuais de pesquisas na área de materiais. Assim, este estudo avaliou a aplicação do resíduo de PRFV em misturas de concreto para a produção de peças para pavimento intertravado. O resíduo apresentou granulometria de agregado miúdo, com módulo de finura de 1,71. A morfologia revelou haver uma superfície heterogênea, com grânulos de diferentes tamanhos e bastonetes alongados lisos. A substituição parcial da areia pelo resíduo de PRFV (5%, 10% e 15%) resultou em peças com menor resistência à compressão (< 31 MPa) quando comparadas ao controle, sem PRFV. Entretanto, os resultados de resistência permitem a aplicação dos pavers em lugares com tráfego leve ou mesmo em calçadas, com a vantagem de a peça ser mais leve.

Abstract The use of polymers in industry is expanding, especially glass fiber reinforced polymers (GFRP). The production process of GFPR parts generates significant amounts of waste, which then needs to be disposed of in industrial landfills, which both generates financial costs for the industrial sector and constitutes an environmental problem. The search for solutions that incorporate the waste either in the process or as a substitute for raw materials is one of the current concerns of research into materials. This study evaluates the application of GFRP waste in concrete mixtures for the production of interlocking pavers. The waste presented fine aggregate granulometry, with a fineness modulus of 1.71. The morphology revealed a heterogenous surface, with granules of different sizes and smooth and elongated stems. The partial replacement of sand by GFRP residue (5%, 10% and 15%) resulted in pavers with lower compressive strength (< 31 MPa) when compared to the control specimens without GFRP, however, the strength results allow the application of pavers in places with light traffic or on sidewalks, with the advantage that these pavers are lighter.

RESUMO Este trabalho consiste na avaliação do comportamento mecânico, em especial da vida de fadiga, de algumas misturas asfálticas tradicionalmente utilizadas no estado de Goiás, Brasil. Para a preparação das amostras, a granulometria dos agregados foi definida por meio da metodologia Bailey e em seguida verificada pela Fração do Agregado Dominante (FAD). Além dos ensaios de fadiga, outros ensaios laboratoriais foram realizados para avaliação do comportamento mecânico das misturas. Os resultados obtidos nesta pesquisa indicaram que somente a seleção granulométrica a partir da metodologia Bailey não foi suficiente para que as mistura estudadas apresentassem melhorias quanto à deformação permanente, sendo necessário, portanto, a análise da porosidade FAD bem como da realização de ensaios mecânicos como o ensaio uniaxial de carga repetida para determinação do Flow Number. As misturas estudadas apresentaram bom comportamento quanto à fadiga se enquadrando na Classe 4 da metodologia utilizada no software brasileiro de dimensionamento de pavimentos (MeDiNA). Assim, constata-se que quanto à fadiga, as misturas estudadas podem ser consideradas satisfatórias. No entanto, em termos de deformação permanente elas não apresentaram o desempenho necessário, sendo que a adequação granulométrica baseada apenas na metodologia Bailey não foi suficiente para melhorar o Flow Number. A partir desses resultados, recomenda-se que a faixa indicada para o FAD seja atendida e que outros tipos de ligantes asfálticos sejam incorporados nessas misturas para obter melhor desempenho.

ABSTRACT This paper consists in the evaluation of asphalt mixtures regarding their mechanical behavior, especially the fatigue life of some asphalt mixtures traditionally used in the state of Goiás, Brazil. For sample preparation, the grain size distribution of the aggregates was defined using the Bailey methodology and then checked by the Dominant Aggregate Size Range (DASR). Besides the fatigue tests, other laboratory tests were performed to evaluate the mechanical behavior of the mixtures. The results obtained in this research were able to demonstrate that only the particle size selection from the Bailey methodology was not enough for a given mixture to present improvements in terms of permanent deformation. Therefore, analysis of the DASR porosity as well as mechanical tests such as the uniaxial repeated load test for determination of the Flow Number were necessary. The studied mixtures presented good fatigue behaviour and fit in Class 4 of the methodology used in the Brazilian design software (MeDiNA). Thus, this study points that for fatigue performance, the studied mixtures can be considered satisfactorily. However, in terms of permanent deformation they do not showed the necessary behavior, and the grain size adjustment based only at the Bailey method was not enough to improve the Flow Number. From these results, it is recommended that the DARS porosity range must be considered and other types of asphalt binders be incorporated into these mixtures to achieve their best performance.

ABSTRACT Due to the increasing susceptibility of water bodies used as sources for public supply to various contaminants and the limited efficiency of conventional water treatment, there is a need to investigate complementary and/or alternative treatment techniques. The aim of this study was to evaluate the efficiency of different biofiltration conceptions, on a bench scale, for the removal/biodegradation of diuron and microcystins, in concentrations of the order of 1000 μg·L−1 of diuron and 50 μg·L−1 of microcystins, in the granular materials slow filter sand, rapid filter sand and granular activated carbon in a laboratory filter. The study was carried out in two distinct experimental phases: with natural biological activation (Phase 1) and with specific biological activation, with the addition of a bacterial culture proven to be active for the degradation of microcystins Sphingosinicella microcystinivorans — B9 (Phase 2). Natural activation showed greater efficiency in relation to the removal of diuron and microcystins, as well as the complementary parameters for all granular media. Specific activation with B9 bacteria proved to be complex in relation of controlling its activity and interfered negatively in the removal of diuron and microcystins when compared to natural activation, including in the granular activated carbon filter. For sand filters, the use of coarser granulometry, such as the rapid filter sand, may be promising because it presents easier handling and cleaning, slower clogging and lower cleaning frequency, in addition to a similar performance to the filter with slow filter sand in relation to the removal of diuron and microcystins.

RESUMO Devido à susceptibilidade crescente dos mananciais utilizados como fontes para abastecimento público aos diversos contaminantes e à limitada eficiência do tratamento convencional de águas, há a necessidade de se investigarem técnicas complementares e/ou alternativas de tratamento. O objetivo deste estudo foi avaliar a eficiência de diferentes concepções de biofiltração, em escala de bancada, para a remoção/biodegradação de diuron e microcistinas, em concentrações da ordem de 1.000 μg·L−1 de diuron e 50 μg·L−1 de microcistinas, nos materiais granulares areia de filtro lento, areia de filtro rápido e carvão ativado granular em filtro de laboratório. O estudo foi realizado em duas fases experimentais distintas: com ativação biológica natural (Fase 1) e com ativação biológica específica, com adição de cultura de bactéria comprovadamente ativa para degradação de microcistinas Sphingosinicella microcystinivorans — B9 (Fase 2). A ativação natural apresentou maior eficiência em relação à remoção de diuron e microcistinas, bem como aos parâmetros complementares para todos os meios granulares. A ativação específica com bactéria B9 mostrou ser complexa em relação ao controle de sua atividade e interferiu negativamente na remoção de diuron e de microcistinas quando comparada à ativação natural, inclusive no filtro de carvão ativado granular. Para os filtros de areia, o emprego de granulometria mais grossa, como a areia de filtro rápido, pode ser promissor por apresentar manejo e limpeza facilitados, colmatação mais lenta e menor frequência de limpeza, além de desempenho similar ao do filtro com areia de filtro lento em relação à remoção de diuron e microcistinas.

Abstract The Pantanal comprehends a set of heterogeneous and biodiverse landscapes of esteemed environmental, economic and social value. The study of soils is effective to stratify and to understanding the operation of these environments. The purpose of this study was to characterize and compare soils of lake landscapes of the Pantanal: baías (freshwater lakes), salinas (alkaline lakes) and their respective levees (sandy ridges originally with forest vegetation). For this purpose, we carried out field work with sampling, in triplicate, of superficial soil layers in 12 representative areas of low and high Nhecolândia; analytical determinations of 26 soil attributes were performed, totaling 936 response variables and statistical analyses were performed in order to synthesize the data and present the results. In both landscapes, the fine sand fraction predominates in the soil granulometry. The textural class of the soils varied from very sandy, medium sandy and medium sandy for the baías; very sandy for the levees, with particle density related to the presence of quartz; and very sandy, medium sandy, medium clayey and clayey for the salinas. In the chemical attributes and organic matter, the baías stand out for higher potential acidity (H+Al), slightly high organic matter contents and availability of metal ions, especially Fe; in the levees, higher average remaining phosphorus (Prem) are more evident; while the saline lake soils are related to more alkaline pH values, high base saturation and high Sodium Saturation Indices (ISNa). Salinas landscapes presented the highest data variability and have soil attributes that refer to the action of different environmental processes.

Resumo O Pantanal compreende um conjunto de paisagens heterogêneas e biodiversas de estimado valor ambiental, econômico e social. O estudo dos solos é efetivo para estratificar e compreender o funcionamento desses ambientes. Objetivou-se caracterizar e comparar solos de paisagens lacustres do Pantanal Sul-Mato-Grossense: baías (lagos de água doce), salinas (lagos alcalinos) e suas respectivas cordilheiras (cordões arenosos originalmente com vegetação florestal). Para tanto, realizou-se trabalho de campo com amostragens, em triplicata, de camadas superficiais do solo em 12 áreas representativas da baixa e alta Nhecolândia; procedeu-se determinações analíticas de 26 atributos do solo, totalizando 936 variáveis resposta e; análises estatísticas foram realizadas visando a síntese dos dados e apresentação dos resultados. Em ambas as paisagens predomina a fração areia fina na granulometria do solo. A classe textural dos solos variou de muito arenosa, arenosa média e média arenosa para as baías; muito arenosa para as cordilheiras, com Dp relacionada a presença do quartzo; e muito arenosa, arenosa média, média argilosa e argilosa para as salinas. Com relação aos atributos químicos e matéria orgânica, as baías se destacam pela maior acidez potencial (H+Al), teores de MO ligeiramente elevados e disponibilidade de íons metálicos, sobretudo Fe; nas cordilheiras, maiores médias de P-rem são mais evidentes; já os solos de salinas se relacionam a valores de pH mais alcalinos, elevada saturação por bases e altos índices de saturação por Sódio (ISNa). Paisagens de salinas apresentaram a maior variabilidade de dados e possuem atributos do solo que remetem a ação de diferentes processos ambientais.

ABSTRACT Economic instability scenarios and reduction in charcoal consumption, such as those that occurred in 2009 and 2016, affect production and result in the maintenance of eucalyptus forests and an increase in the rotation age. The objective of this work was to evaluate the quality of wood from four Eucalyptus clones (clones 1, 2, 3, and 4) at the ages of 108 and 120 months and the charcoal produced in a rectangular kiln. We evaluated the heart/sapwood ratio, basic density, dry mass per hectare.year, and chemical composition . The carbonizations were performed in a rectangular kiln (210 m³ of wood). We determined the gravimetric yield and the charcoal properties: density, particle size and percentage of fines, friability index, proximate analysis, and mass of charcoal produced per hectare.year. We verified the significant effect of clones on basic density and dry mass, whose variations were from 494 to 589 kg m-3 and 12.47 to 23.34 ton.ha-1, respectively. The charcoal yield did not differ among clones (34.1%), while the yield of semicarbonized wood varied from 3.2% (clone 4) to 10.7% (clone 3). The particle size of 65% of the charcoal volume of clones 1 and 3 was greater than 30 mm, and 49.5% of clones 2 and 4. We found medium mechanical resistance for charcoal from all four clones. The apparent density ranged from 356 to 458 kg.m-3, with the highest average value for clone 3. We found the highest charcoal production for clones 1 and 2, 7.5 tons per hectare.year. The fixed carbon did not vary among clones (76.92%). The wood properties of the Eucalyptus clones at ages 108 and 120 months are suitable for charcoal production for metallurgical use. Clones 1 (a hybrid of E. urophylla x E. grandis) and 3 (a hybrid of E. urophylla x E. camaldulensis) stood out from the others.

RESUMO Cenários de instabilidade econômica e redução do consumo de carvão vegetal, como as ocorridas em 2009 e 2016, afetam a produção deste insumo, resultando na manutenção das florestas de eucalipto e aumento da idade de corte. O objetivo deste trabalho foi avaliar a qualidade da madeira de quatro clones de Eucalyptus (clones 1, 2, 3 e 4) com idades entre 108 e 120 meses e do carvão vegetal produzido em forno retangular. Para caracterização da madeira, foram avaliadas a relação cerne/alburno, densidade básica, massa seca por hectare.ano e composição química. As carbonizações foram realizadas em forno retangular, com capacidade de 210 m³ de madeira, e determinaram-se o rendimento gravimétrico e as propriedades do carvão vegetal: densidade do carvão vegetal, granulometria e porcentagem de finos, índice de friabilidade, análise imediata, além da massa de carvão produzida por hectare.ano. Verificou-se efeito significativo dos clones na densidade básica e massa seca, com valores de 494 a 589 kg m-3 e 12,47 a 23,34 ton.ha-1, respectivamente. O rendimento médio em carvão vegetal não diferiu entre os clones e foi igual a 34,1%, enquanto o rendimento em atiço variou de 3,2% para o clone 4 a 10,7% para o clone 3. Os clones 1 e 3 apresentaram em média 65% do volume de carvão vegetal na maior faixa granulométrica (>30 mm), enquanto os clones 2 e 4 tiveram 49,5% nessa granulometria. O carvão vegetal dos quatro clones foi de média resistência e a densidade aparente variou de 356 a 458 kg.m-3, com maior valor para o clone 3. Os clones 1 e 2 apresentaram a maior produção de carvão vegetal, 7,5 toneladas por hectare.ano. O carbono fixo não variou entre os clones, apresentando média igual a 76,92%. Os clones de Eucalyptus nas idades de 108 e 120 meses apresentam propriedades da madeira adequadas para a produção de carvão vegetal, alcançando rendimento gravimétrico e qualidade satisfatórios para uso metalúrgico, destacando-se os clones 1 (híbrido de E. urophylla x E. grandis) e 3 (híbrido de E. urophylla x E. camaldulensis).

ABSTRACT Lignin, the second most abundant biopolymer on the planet, has properties that can be widely explored, moving from waste to products with high added value. Therefore, this work aimed to extract and characterize Klason and Kraft lignins from sawdust and black liquor, considered industrial waste. The raw material used was Eucalyptus grandis chips. To obtain Klason lignin according to TAPPI 222 om-02 (2002), part of the chips were transformed into sawdust. To obtain Kraft lignin, another part of the chips passed through a digester to obtain black liquor, which was subsequently subjected to acid precipitation. The characterization of lignins was performed by granulometry analysis, scanning electron microscopy with elemental chemical analysis (EDS), transmission electron microscopy, medium infrared spectroscopy, thermogravimetric analysis and differential calorimetry. Microscopy analyzes showed irregular structures of various shapes, including spherical structures, most evident and frequent in Kraft lignin. The elementary chemical analysis showed that the lignin washing process was satisfactory, due to the small percentage of sulfur detected in the samples. The results of the granulometry confirmed that the lignins had micrometric dimensions. The medium infrared spectra showed the characteristic peaks of the chemical composition of lignin. The thermal analysis showed three ranges of degradation, attributed to the drying of the samples, degradation of the hemicelluloses and the lignin itself. All results confirmed the obtaining of Klason and Kraft lignins. Therefore, the techniques were satisfactory in transforming waste into lignin with the potential for a variety of commercial applications, mainly in the chemical and pharmaceutical industries.

RESUMO A lignina, o segundo biopolímero mais abundante do planeta, possui propriedades que podem ser amplamente exploradas, passando de resíduos a produtos de alto valor agregado. Portanto, este trabalho teve como objetivo extrair e caracterizar as ligninas Klason e Kraft de serragem e licor negro, considerados resíduos industriais. A matéria-prima utilizada foram cavacos de Eucalyptus grandis. Para a obtenção da lignina Klason conforme TAPPI 222 om-02 (2002), parte dos cavacos foi transformada em serragem. Para a obtenção da lignina Kraft, outra parte dos cavacos passou por um digestor para a obtenção do licor negro, que posteriormente foi submetido à precipitação ácida. A caracterização das ligninas foi realizada por análise de granulometria, microscopia eletrônica de varredura com análise química elementar (EDS), microscopia eletrônica de transmissão, espectroscopia de infravermelho médio, análise termogravimétrica e calorimetria diferencial. As análises microscópicas mostraram estruturas irregulares de vários formatos, incluindo estruturas esféricas, mais evidentes e frequentes na lignina Kraft. A análise química elementar mostrou que o processo de lavagem da lignina foi satisfatório, devido ao pequeno percentual de enxofre detectado nas amostras. Os resultados da granulometria confirmaram que as ligninas apresentaram dimensões micrométricas. Os espectros de infravermelho médio mostraram os picos característicos da composição química da lignina. A análise térmica mostrou três faixas de degradação, atribuídas à secagem das amostras, degradação das hemiceluloses e da própria lignina. Todos os resultados confirmaram a obtenção das ligninas Klason e Kraft. Portanto, as técnicas foram satisfatórias na transformação de resíduos em lignina com potencial para diversas aplicações comerciais, principalmente nas indústrias química e farmacêutica.

Abstract: Aim This study focused on the spatiotemporal variation of the benthic diatom community structure in salt marshes from the Patos Lagoon estuary and their relationship with environmental variables. Methods Samplings were carried out in the winter of 2010 and summer of 2011 (during El Niño and La Niña) in sites with different sediment granulometry, salinity, and distances from the Atlantic Ocean. The surface sediment was collected using a core (10 cm in diameter and 2 cm in depth) and the benthic diatoms were removed following the Trapping method, allowing the observation of live diatoms. Results The richness values (18 and 48 taxa), evenness (0.41 and 0.68), and Shannon diversity indices (2.02 and 3.31 bits/ind.) variations were not significative between the sites and seasons, although temperature and salinity differed significatively between winter and summer. However, the diatom's composition and distribution were related to temperature, salinity, and sediment particle size. Mainly the species Hippodonta hungarica, Luticola simplex Navicula cf. cryptotenelloides, N. erifuga, N. jacobii, Nitzschia filiformis var. conferta, Planothidium frequentissimum and Tryblionella calida were associated with lower temperature and lower salinity in the winter. The species Navicula cf. cryptocephala, N. phylleptosomaformis, Nitzschia pusilla, N. frustulum, N. scalpelliformis and Pseudostaurosiropsis geocollegarum were associated with higher temperature and higher salinity in the summer. Birraphid diatom taxa, mainly species of the genus Navicula and Nitzschia, were frequent or abundant in sandy sediments, and monoraphids, such as Planothidium frequentissimum, were frequent in sites where silt and clay predominated. Conclusions The composition of the benthic diatoms revealed variation between the sites in the winter and summer seasons, during El Niño and La Niña episodes. In winter, high rainfall and freshwater runoff maintained oligohaline condition in the marshes, while in summer, flooding with meso-poly-euhaline waters changed the diatom composition. The granulometry was an important factor in explaining the distribution of the birraphid and monorhapid taxa.

Resumo: Objetivo Este estudo focalizou a variação espaço-temporal da estrutura da comunidade de diatomáceas bentônicas, em marisma do estuário da Laguna dos Patos e sua relação com variáveis ambientais. Métodos Amostragens foram realizadas no inverno de 2010 e verão de 2011(durande o El Niño e La Niña) em locais com diferentes granulometrias do sedimento, salinidades e distâncias do Oceano Atlântico. O sedimento superficial foi coletado utilizando um core (10 cm de diâmetro e 2 cm de profundidade) e as diatomáceas bentônicas foram removidas, seguinto o método Trapping, que permite a observação das diatomáceas vivas. Resultados As variações dos valores de riqueza (18 e 48 taxa), uniformidade (0.41 and 0.68) e índice de diversidade de Shannon (2.02 and 3.31 bits/ind.) entre os locais e estações não foram significativos, embora a temperatura e salinidade diferiram, significativamente, entre o inverno e verão. Entretanto, a composição e distribuição das diatomáceas estiveram relacionadas à temperatura, salinidade e tamanho de partícula do sedimento. Principalmente as espécies Hippodonta hungarica, Luticola simplex Navicula cf. cryptotenelloides, N. erifuga, N. jacobii, Nitzschia filiformis var. conferta, Planothidium frequentissimum and Tryblionella cálida, estiveram associadas às mais baixas temperatura e salinidade no inverno. As espécies Navicula cf. cryptocephala, N. phylleptosomaformis, Nitzschia pusilla, N. frustulum, N. scalpelliformis and Pseudostaurosiropsis geocollegarum estiveram relacionadas as mais altas temperatura e salinidade no verão. Diatomáceas birrafídeas, principalmente espécies do gênero Navicula e Nitzschia foram frequentes ou abundantes em sedimentos arenosos e, monorrafídeas, tais como Planothidium frequentissimum foram frequentes em locais, onde predominaram silte e argila. Conclusões A composição das diatomáceas bentônicas revelou variação entre os locais nas estações de inverno e verão, durante os episódios de El Niño and La Niña. No inverno, alta pluviosidade e alto escoamento de água doce manteve condição oligohalina nas marismas, enquanto que, no verão, a inundação de água meso-poly-euhalina mudou a composição das diatomáceas. A granulometria foi um fator importante para explicar a distribuição dos táxons birrafídeos e monorrafídeos.