Influence of the Surface Viscosity on the Breakup of a Surfactant-Laden Drop

We examine both theoretically and experimentally the breakup of a pendant drop loaded with an insoluble surfactant. The experiments show that a significant amount of surfactant is trapped in the resulting satellite droplet. This result contradicts previous theoretical predictions, where the effects of surface tension variation were limited to solutocapillarity and Marangoni stresses.We solve numerically the hydrodynamic equations, including not only those effects but also those of surface shear and dilatational viscosities. We show that surface viscosities play a critical role to explain the accumulation of surfactant in the satellite droplet.Ministerio de Economía y Competitividad DPI2013-46485-C3-1-R, TRA2013- 45808-RJunta de Extremadura GR1004

Molecular dynamics study on water confinement in deep eutectic solvents

The nanoscopic properties of highly diluted water solutions in choline chloride + lactic acid deep eutectic solvent was studied using molecular dynamics simulations as a function of concentration and temperature with the objective of characterize the confinement of water in deep eutectic solvents as a non-regular confinement mechanism. The simulations allowed the analysis of changes in the properties of the deep eutectic solvent in response to the water presence as well as the behaviour of confined water in solvent cavities. The analysis of structural, energetic and dynamic factors provides for the first time the characterization of water confined in these environmentally friendly solvents. The results showed how water can be confined in deep eutectic solvents liquid cages maintaining water individuality with minor changes in the solvent properties, which can be used for tuning water properties for the development of technological applications.Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00). We acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities

Moisture Evaporation from Granular Biopesticides Containing Quiescent Entomopathogenic Nematodes

The moisture evaporation process from granular biopesticides (GBs) containing entomopathogenic nematodes (EPNs) has influence in the shelf-life of these biological products, but the approach to design GBs with desired transport properties lacks of theoretical support to get closer in a better way to formulations design of long-term storage. In this chapter we review the state of art in theoretical studies about the physics of the moisture evaporation to elucidate what are the mechanisms of drying of GBs. We found that several external and internal factors influence the transport process of moisture exchange among others phenomenon that happened in a porous media such as GBs; consequently, complex and highly dynamic interactions between medium properties, transport processes, and boundary conditions result in a wide range of evaporation behaviors. The theory of drying process in two stages for porous materials with high moisture content seems to be a good starting point to explore further the drying of GBs at different scales and mechanistic and correlative models of evaporation are available to analyze the desiccation in different stages of the elaboration process, which is also of interest in the subject area of science and technology of the formulation of EPNs

Tuning the properties of ionic liquids by mixing with organic solvents: The case of 1-butyl-3-methylimidazolium glutamate with alkanols

Binary liquid mixtures of 1-butyl-3-methylimidazolium glutamate acid ([bmim][glu]) with alkanols (1-propanol, isobutanol and 1,2-propanediol) are studied in the full composition range as a function of temperature using a combined experimental and computational chemistry approach. Experimental thermophysical information as well as derived excess and mixing properties allowed to characterize these complex liquid mixtures in terms of deviation from ideality as well their relationships with the developed intermolecular forces and changes with the type of considered alkanols. Theoretical studies using quantum chemistry and classical molecular dynamics simulations provided nanoscopic characterization on the studied fluids, with particular attention to the extension and nature of hydrogen bonding and its effects on molecular arrangements and mixed fluids’ properties. The reported study provides a micro and macroscopic characterization of the considered aminoacid-based ionic liquid mixtures, thus contributing to the knowledge of sustainable ionic liquid systems mixed with organic solvents for fine tuning properties and developing task specific applications.Shiraz University of Technology and Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00)

Theoretical study on molten alkali carbonate interfaces

The properties and structure of relevant interfaces involving molten alkali carbonates are studied using molecular dynamics simulation. Lithium carbonate and the Li/Na/K carbonate eutectic mixture are considered. Gas phases composed of pure CO2 or a model flue gas mixture are analyzed. Similarly, the adsorption of these gas phases on graphene are studied, showing competitive CO2 and N2 adsorption that develops liquid-like layers and damped oscillation behavior for density. The interaction of the studied carbonates with graphene is also characterized by development of adsorption layers through strong graphene–carbonate interactions and the development of hexagonal lattice arrangements, especially for lithium carbonate. The development of molten salts–vacuum interfaces is also considered, analyzing the ionic rearrangement in the interfacial region. The behavior of the selected gas phases on top of molten alkyl carbonate is also studied, showing the preferential adsorption of CO2 molecules when flue gases are considered.European Union’s H2020- MSCA-RISE-2016-CO2MPRISE-73487

Insights into carbon nanotubes and fullerenes in molten alkali carbonates

The properties of single-walled carbon nanotubes and carbon fullerenes in molten alkali carbonates (MACs) were studied as a function of the considered nanomaterial and the ions into the molten salt using classical molecular dynamics simulations. The adsorption and confinement in carbon nanotubes is developed by efficient interaction of carbonate ions in the inner and outer walls of the nanotubes whereas alkali cations do not show a remarkable interaction with the nanomaterial. Analogous solvation mechanisms are inferred for carbon fullerenes with large disruption of the liquid structuring of MAC at high fullerene concentrations. The solvation ability of the studied lithium–sodium–potassium carbonate eutectic mixture for both types of nanomaterials is essential for considering this fluid in the development of composite materials for advanced technological applications.European Union H2020- MSCA-RISE-2016-CO2MPRISE-73487

Insights on biodiesel blends with alkanol solvents

Thermophysical properties of mixtures of fatty acid esters with alkanols were measured in the whole composition range as a function of temperature for understanding features of biodiesel blends. Excess and mixing properties calculated from experimental measurements allowed to quantify and analyze the intermolecular forces in the considered systems. Likewise, molecular modelling studies using quantum chemistry and classical molecular dynamics simulations led to a detailed characterization of these systems at the nanoscopic level. The nature of hydrogen bonding in these liquid mixtures was particularly analyzed from macroscopic properties and theoretical modelling results. The reported experimental and computational study allowed to infer the relationships between the intermolecular forces and additional microscopic features and the mixtures macroscopic properties, which are relevant for the development and characterization of biodiesels. The non-ideality behavior of the studied systems shows relevant changes in hydrogen bonding structuring upon mixing, with the fatty acid esters largely disrupting the alcohols self-association, although ester – alcohol hydrogen bonding is developed, this type of interactions is remarkably weaker than those for alcohols. Therefore, the studied biodiesel blends macroscopic properties may be tuned and controlled through the amount of alcohols in the mixtures and rooted on its effect on hydrogen bonding.Shiraz University of Technology (Iran), Junta de Castilla y León (Spain, project BU094G18) and Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00) for supporting this project. We also acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities

Biomass Assessment of Peach Trees in the Ecuadorian Andes

This work focused on the evaluation of four essential aspects of biomass based on peach trees grown in the Andean region of Ecuador. In one case, mathematical models have been developed allowing the amount of lignocellulosic material to be quantified from easily measurable parameters such as crown diameter, stem diameter and plant height. Performing quick surveys, these equations led to obtain the amount of biomass contained in a plot. In a second case, elemental analysis of biomass was performed in order to determine the amount of CO2 captured from the atmosphere through photosynthesis during its growth, and thus to assess the contribution of these plots in mitigating climate change. Afterwards, residual biomass from pruning was quantified and a proximal analysis was carried out. This allowed us to assess the suitability of these materials as solid biofuels. The models obtained to determine the volume of the branches gave determination coefficients of 0.98. Models to quantify the biomass of the whole plant had r2 of 70%. The density of the dried material was 0.92 g/cm3, obtaining an average dry wood weight of 44.8 kg per plant. This represents a content of 1682 moles of captured CO2 of a developed plant crop (3 years). The average ash on dry wood was 3%, fixed carbon content on dry wood was 7%, and volatile content dry wood was 78%. The moisture content of waste materials after pruning was 45.96%. The drying time in store for humidity below 10%, suitable for burning boiler, was 15 days. The higher heating value of peach wood was 18.92MJ/kg.Este trabajo se centró en la evaluación de cuatro aspectos esenciales de la biomasa de árboles de durazno cultivados en la región andina del Ecuador. En un caso, se han desarrollado modelos matemáticos que permiten cuantificar la cantidad de material lignocelulósico a partir de parámetros fácilmente medibles como el diámetro de la copa, el diámetro del tallo y la altura de la planta. Realizando levantamientos rápidos, estas ecuaciones permitieron obtener la cantidad de biomasa contenida en una parcela. En un segundo caso, se realizó un análisis elemental de la biomasa para determinar la cantidad de CO2 capturado de la atmósfera a través de la fotosíntesis durante su crecimiento, y así evaluar la contribución de estas parcelas en la mitigación del cambio climático. Posteriormente se cuantificó la biomasa residual de la poda y se realizó un análisis proximal. Esto nos permitió evaluar la idoneidad de estos materiales como biocombustibles sólidos. Los modelos obtenidos para determinar el volumen de las ramas arrojaron coeficientes de determinación de 0,98. Los modelos para cuantificar la biomasa de toda la planta tenían un r2 del 70 %. La densidad del material seco fue de 0,92 g/cm3, obteniendo un peso promedio de madera seca por planta de 44,8 kg. Esto representa un contenido de 1682 moles de CO2 capturado de un cultivo vegetal desarrollado (3 años). La ceniza promedio en la madera seca fue del 3 %, el contenido de carbono fijo en la madera seca fue del 7 % y el contenido de volátiles en la madera seca fue del 78 %. El contenido de humedad de los materiales de desecho después de la poda fue del 45,96 %. El tiempo de secado en almacenamiento para humedad inferior al 10 %, apto para caldera de combustión, fue de 15 días. El poder calorífico superior de la madera de durazno fue de 18,92 MJ/kg

Cytotoxic Activity of Essential Oils of Some Species from Lamiaceae Family

Cancer is considered one of the most lethal diseases in the world, with a prevalence of 439.2 cases and 163.5 deaths per 100,000 inhabitants, in the period from 2011 to 2015; this disease has a greater impact in underdeveloped countries. For the treatment of this disease, a combination of chemotherapy with surgery or radiation is generally used, however, it is not exempt from adverse effects or resistance of the tumor to this type of treatment, for this reason the search for new treatments is constant. The plants are a possible source to achieve this; Lamiaceae is a family of plants widely distributed on the planet and has been used traditionally for the treatment of different diseases, and various essential oils with the potential for cancer treatment have been isolated from this species. The scope of this review is to present 46 essential oils isolated from different species of Lamiaceae which have been tested against different cancer cell lines

Cavidad de Stafne de localización inusual en el sector anterior mandibular

La típica cavidad de Stafne, localizada en el sector posterior de la mandíbula, es una entidad relativamente poco frecuente, pero cuando el defecto se sitúa en la región anterior mandibular, es bastante raro, habiéndose descrito hasta ahora sólo 36 casos en la literatura científica. La mayoría de estos defectos aparecen entre la quinta y la sexta décadas de la vida, están localizados en el área de caninos y premolares, y muestran también una predilección por el sexo masculino. El canal dentario inferior, uno de los hitos anatomo-radiológicos principales que ayudan al diagnóstico de la cavidad de Stafne en la zona posterior, raramente está presente anteriormente al agujero mentoniano. Por ello, por su apariencia radiográfica más variable que en el defecto posterior, por soler encontrarse superpuesta a los ápices de los dientes, y por la rareza de presentación en el sector anterior mandibular, es mucho más difícil establecer un diagnóstico definitivo de cavidad de Stafne en esta localización, y por tanto es más fácil que pueda haber un error en el diagnóstico, sobre todo inicialmente. Presentamos un nuevo caso, en un varón de 68 años, en el que el diagnóstico fue fortuito, y revisamos especialmente sus aspectos etiopatogénicos, clínicos, y de diagnóstico diferencial.The typical Stafne's cavity, located on the posterior portion of the mandible, is a relatively uncommon entity. However, when the defect is located in the anterior region of the mandible, it is quite rare, having thus far been described in only 36 cases in the scientific literature. Most of these defects appear in the fifth and sixth decades of life, are localized to the area of the canines and premolars, and have a predilection for males. The inferior dental canal, one of the anatomical-radiographic landmarks that aid in the diagnosis of Stafne's cavity in the posterior region, is rarely present anterior the mental foramen. For this reason, because of its more variable radiographic appearance compared to the posterior defect, its tendency to be superimposed over the apices of the teeth, and the rarity of its localisation to the anterior mandible, it is much more difficult to establish a definitive diagnosis of a Stafne's cavity in this location. It is therefore more likely that a diagnostic error can occur, especially early on. We present a new case in a 68-year-old male in which the diagnosis was serendipitous, and we review in particular the aetiology and pathogenesis, clinical aspects, and differential diagnoses for this condition