The design of green fiber-reinforced nanocomposites with enhanced properties and durability has attracted attention from scientists. The present study aims to investigate the potential of bacterial nanocellulose (BNC) as a green additive for fiber-cement composites. Inverse gas chromatography (IGC) was used to evaluate the influence of incorporation of BNC as powder or gel, or coated onto the bagasse fibers, on the fiber-cement composite (FCC) surface. The results indicated that BNC incorporation made the FCC surface more reactive, increasing the dispersive component of the surface energy. The most relevant effects were found for BNC incorporation as gel or coated on the fibers. Incorporation of BNC as gel resulted in a predominantly organic FCC surface with substantial decreased surface basicity (K a /K b ratio from 2.88 to 5.75). IGC also showed that FCC with BNC incorporated as gel was more susceptible to hydration. However, BNC coated on fibers prevented fiber mineralization, increasing the inorganic materials at the surface, which caused an increase in the surface basicity (K a /K b ratio decrease to 2.00). These promising results could contribute to development of a new generation of green hybrid composites. The IGC technique enabled understanding of the physicochemical changes that occur on deliberate introduction of nanosized bacterial cellulose into fiber-cement composites.Keywords Bacterial nanocellulose Á Bagasse fiber Á Green composites Á Inverse gas chromatography (IGC) Á Fiber-cement composites

La estructura corresponde al edificio donde funciona el Municipio de Flavio Alfaro; es una edificación compuesta por vigas y columnas, proyectada para 3 pisos en hormigón armado y luego se realizó una ampliación con una cubierta de lámina delgada, muy mal construida y colapsó parcialmente. Se  realiza  un  análisis  espectral empleando los  espectros obtenidos  en  Chone  del terremoto del 16 A; en la estructura original con el objeto de evaluar en forma cualitativa el desempeño sísmico de la edificación. Posteriormente se plantean dos opciones de reforzamiento la primera en que se derroque la ampliación realizada y se le confiera amortiguamiento a la estructura mediante la colocación de disipadores de energía TADAS y la segunda en que se deja la estructura de cuatro pisos pero estructurando en forma adecuada la cubierta y de igual manera se coloquen los disipadores de energía. Palabras Clave: Reforzamiento con Disipadores de Energía TADAS. Terremoto del 16 A. Municipio de Flavio Alfaro.

No abstract

Tomato is one of the most consumed vegetables in the world, and its intake is known to be beneficial for human health. The nutritional quality of tomato is connected with numerous factors namely the cultivation system. To achieve the highest fruit quality and yield, the cherry tomato (Lycopersicon esculentum Mill. var. Moscatel RZ) was cultivated in three cultivation systems and its nutritional quality was evaluated. The highest fruit productivity, 2135-2240 g plant -1 dry weight (dw), was observed for the cherry tomatoes grown in the soilless systems. The cherry tomato from the hydroponic culture had the highest protein (13.41% dw), lipid (3.20% dw), sugar (354.94 mg g -1 dw) and taste index (1.24). It also comprised high amounts of monounsaturated and polyunsaturated fatty acids, like oleic (1.28 mg g -1 dw) and linoleic acids (5.42 mg g -1 dw). With respect to cherry tomato from the organic culture, higher contents of carotenoids-lycopene (47.1 mg kg -1 dw) and polyphenols (56.7 mg GAE 100 g -1 dw) were verified. Flavonoids were the main family of phenolic compounds found in the cherry tomato. The highest levels of chalconaringenin (51.95 mg 100 g -1 dw) and rutin (39.69 mg 100 g -1 dw) were observed in the cherry tomatoes cultivated through organic practices. This study shows that the agronomic system greatly influences the different characteristics associated with fruit quality. Hydroponic cultures presented higher quality, namely texture and taste, while the higher amounts of bioactive compounds were found in the organic culture.

This work highlights the evolution of flood disasters and their impacts upon environmental and socioeconomic aspects both worldwide and in Small Island Developing States (SIDS) in particular. For our research, we reviewed the stress factors affecting flood disasters and performed surveys of two focus groups in Funchal municipality on Madeira Island (Portugal). Our research identifies the main causes of the serious impacts that flash floods can have on Funchal city. These include: The occupation of floodplain areas, Canalization of water courses, Erosion and transport of soil from upstream hillslopes due to deforestation, and Intensive precipitation of long duration.

En el sismo de 1998 que afectó a Bahía de Caráquez, algunas estructuras fueron reparadas pero no fueron reforzadas y en el terremoto del 16 de abril de 2016, de Pedernales, sucedió lo que tenía que suceder, tuvieron un mal comportamiento sísmico. En este artículo se presentan cuatro casos y son: Edificio Cabo Coral, Hotel Italia, Edificio Cevallos, Edificio Cedeño, ubicados en Bahía de Caráquez El objetivo de este artículo es concientizar a la comunidad de que se si una estructura tuvo año extensivo en la mampostería es necesario reforzar la estructura, no solo repararle y para ello se necesita contar con un espectro de diseño obtenido de un estudio de peligrosidad sísmica, conocer el tipo de suelo en que se halla la estructura mediante estudios geofísicos y en base a esta información ver la forma más idónea de reforzamiento.

No abstract

On 16 April 2016, an earthquake of Mw 7.8 shook the coast of Ecuador, causing the destruction of buildings and a significant number of casualties. Following a visit by the authors to the city of Portoviejo during the debris removal and recovery stage, it was noted that several reinforced concrete buildings located on corners had collapsed in the central part of the city. These buildings were characterized by the presence of masonry at the edges of the buildings but not between the two mostly open-plan facades on the corner for practical reasons. This article reviews the effect of masonry infill panels on the seismic response of reinforced concrete structures. For this, a model that contains the geometric and mechanical characteristics typical of collapsed buildings was generated and subjected to nonlinear analysis, with both static and dynamic increments. The results show the clear influence of the masonry infill panels on the structural response through the torsional behavior that is reflected in the evolution of the floor rotations. Finally, dynamic incremental analysis is used to obtain the collapse fragility curve of the building, and a new damage measure based on floor rotations is proposed.