Closed flow solar dehydration with the use of silver nanoparticles: Application for the production of Pouteria lucuma flour

In this research, a closed-flow solar dehydrator with a refrigeration moisture extraction system was evaluated, likewise, the dehydration temperature time was optimized by evaluating three types of heat transfer fluids. The dehydration equipment included devices to absorb thermal energy from incident sunlight, such as a trombe wall and a parabolic cylindrical collector, and a thermo bank system. In addition, the influence of three types of heat transfer fluids (water, oil and oil nanofluidþsilver nanoparticles) was evaluated. This dehydration system was applied to process the Pouteria lucuma fruit. The results indicate the reduction of the dehydration time by 58.19% using nanofluid. This treatment prevents the modification of the physicochemical properties of the product and helps preserving its organoleptic propertiesinfo:eu-repo/semantics/publishedVersio

Sustainable tourism policies in Peru and their link with renewable energy: analysis in the main museums of the Moche route

Tourism activity in Peru has been experiencing significant growth in the last ten years, positioning this economic sector as the third largest contributor to the National Gross Domestic Product (GDP). Likewise, Peru has a high ecological and climate diversity, which makes it the possessor of renewable energy potential, specifically solar and wind power. The rapid growth of tourism is leading to generating prospects for becoming a sustainable destination. In this sense, it is important to understand and evaluate the Peruvian legislative framework for sustainable tourism and the current state of the implementation of the scenarios provided by the governmental entity in terms of sustainability, and its link with tourism activity. Based on what has been described, this study is aimed at evaluating the four most relevant museums in the northern part of Peru; in addition, it contributes to the studies that exist at the intersection of tourism and sustainability in the chains of activities related to tourism and calls for rationality applied to tourism management in this region of Latin America. The results of the literature review of the Peruvian legal framework reveal a lack of specific laws and regulations on sustainable tourism; on the contrary, there are policies in force that contribute to promoting the development of sustainable tourism. The quantified evaluation of the solar and wind potentials of the geographical area under study indicates the minimum renewable energy potential necessary for its transformation and use in the development of sustainable museums and its contribution to sustainable tourism

Reuse of organic waste from Eucalyptus globulus extract with high reducing potential in the green synthesis of silver nanoparticles

The research provides a new and sustainable methodology for the synthesis of silver nanoparticles, using Eucalyptus globulus extract, this due to the fact that it presents metabolites capable of acting as a reducing potential of our silver nitrate precursor, and thus obtaining nanostructured material. This is also associated with the reuse of this type of organic material, which currently abounds as waste in the Peruvian highlands. In the specific case of this research, the effect on the stability over time of the biosynthesized silver nanoparticles was evaluated by varying the pH, with values of 4.82, 8.05 and 10.15. It was observed that as the pH increases the production of nanoparticles is higher, having a saturation threshold close to pH 8. It was also found that for alkaline pH close to 10 a more complete reaction of the reducing agent occurs, but with a high dispersion

Influence of the volume of ascorbic acid in the synthesis of copper nanoparticles mediated by chemical pathway and its stability over time

In the present investigation, the effect of ascorbic acid volume in the synthesis of copper nanoparticles (Cu NPs) mediated by chemical route and their stability over time was evaluated. For the synthesis, copper sulfate pentahydrate CuSO4 (5H2O) was used as a precursor agent and ascorbic acid (AA) as a reducing agent. Cu NPs was characterized by the following techniques: UV-Visible spectrophotometry to evaluate structural changes that are evidenced in the absorbance peak and atomic absorption spectrophotometry to define nanoparticulate concentrations material in the precipitated and supernatant phases generated. On the methodology it was possible to observe a controlled formation based on the increase in the volume of ascorbic acid in the presence of sodium hydroxide, noticing a production of Cu nanostructures with a tendency to oxidation over time. The UV-visible results showed characteristic surface plasmon resonance peaks of metallic copper for the colloid containing 1.2 mL of A.A; as well as a specific copper concentration of 0.14 ppm in the supernatant and 1519.1 ppm in the precipitate. It is also evidenced that the solution exhibits a rapid reaction on exposure to air by shifting the absorbance peak to 386 nm. In addition, it does not present notable photosensitivity with respect to exposure to sunlight

Ecological and sustainable synthesis of silver nanoparticles from alcoholic extract of Eucalyptus globulus: evaluation of alcoholic solvent influence (70 and 96 )

The present study provides an ecological and sustainable methodology for obtaining nanostructured material from Eucalyptus globulus leaf extract, as a potential value-added alternative and a contribution to circular economy. Silver nanoparticles (NP Ag) were synthesized, through the reducing action of the alcoholic extracts of eucalyptus on the precursor silver nitrate (AgNO3) evaluating the influence of alcoholic solvent (70 ° and 96 °) and pH in the synthesis. The silver colloids obtained were evaluated by UV-vis spectrophotometry, which shows the formation of nanoparticles through the plasmon resonance peak; showing that for pH values 9.9 and 10 with alcohol extract of 70 ° and 96 ° respectively, silver nanoparticles with plasmon resonance peaks at 410 nm and 412.5 nm are obtained. While for pH values 3.86, 11.8 (96°) and 4.7, 8.2 (70°) nanoparticles with higher polydispersity and in a lower proportion are obtained. The results suggest that the alcoholic extracts of eucalyptus can act as reducing agents and that the optimum pH value for the synthesis of silver nanoparticles corresponds to 10

Películas biodegradables activas a partir de almidón de mango integradas con nanopartículas de plata sintetizadas por química verde

Este trabajo tuvo como finalidad fabricar películas biodegradables fabricadas a partir de almidón de semillas de mango incorporando nanopartículas de plata en estado coloidal y comprobar su potencial para ser usado como material activo. Las nanopartículas de plata fueron fabricadas mediante ruta verde a partir de residuos de uva y fueron añadidas en el proceso de gelatinización de las películas en concentraciones de 3% y 6% v/v. Las nanopartículas de plata fueron caracterizadas mediante espectroscopía UV-Vis y FTIR, mientras que las películas fabricas fueron caracterizadas mediante su densidad y % de contenido de humedad. Las propiedades activas se caracterizaron usando cinética de absorción de agua y biodegradación por enterramiento en suelo. Se encontró un efecto en las características físicas y propiedades activas de las películas debido a la integración de nanopartículas de plata. Se observó un aumento en la densidad, una reducción del contenido de humedad, así como una desaceleración considerable de la cinética de absorción de agua, características que pueden ser aprovechadas para la fabricación de materiales activos

Proposal for a solar fruit dryer design with organoleptic properties recovery system

With the passing of time, the demand for dehydrated organic products has increased, ranging from vegetables to fruits, however in the latter efforts to achieve a quality product have led to the use of industrialized systems which depend on the use of fossil fuels or systems that use electric current which greatly increase production costs. At present, various solar dryer models have emerged, having achieved an optimal performance in what corresponds to the processing of vegetables, however in the processes of dehydration of fruits the results have not been satisfactory, due to the loss of its color, taste, aroma and texture (organoleptic properties). Faced with this problem, an innovative design of solar fruit dehydrator is proposed, which has two objectives, the first related to recovering the organoleptic properties through a system of condenzation, cyclic dehydration and the synchronization of the calorific balance, and the second one focused on the improvement of thermal efficiency, through the use of some heat piles and a trombe wall. The heat transfer fluid was improved, adding silver nanoparticles (silver nanospheres), which were synthesized using the green chemistry method; the efficiency of the heat transfer fluid was increased by 30%

Trichodinidae in commercial fish in South America.

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