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

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

Effect of the temperature and relative humidity in stored sotol (Dasylirion cedrosanum Trel.) seeds on fungi biodiversity

The objective of the research was to identify the fungi in sotol seeds at different conditions of temperature and relative humidity. Seeds were collected at Buñuelos, municipality, and taken to the Laboratory of the Center for Training and Development in Seed Technology (CCDTS) at Universidad Autonoma Agraria Antonio Narro. The seed was stored for a period of 90 days, whit conditions of 60, 75, 80 and 85% of relative humidity kept at 5, 15 and 25 °C. Fungi identifying by morphological criteria. A completely randomized experiment using R software, with factorial arrangement whit two replications. Pathogens identified were: Aspergillus glaucus, Aspergillus niger, Fusarium sp., Penicillium sp., Aspergillus candidus, Cladosporiun sp., Alternaria sp. and Aspergillus chraceus, the results showed that the higher the humidity, temperature and storage time, the incidence of fungi tends to be higher. Fungi with a higher presence in sotol seeds were: Aspergillus glaucus and Penicillium sp. Safe storage environments for sotol seeds reported in this work are 5 °C and a relative humidity of 60-75%. Sotol seeds tolerates conditions of 15 °C and a relative humidity up to 75%.&nbsp

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

Microtiming patterns and interactions with musical properties in Samba music

In this study, we focus on the interaction between microtiming patterns and several musical properties: intensity, meter and spectral characteristics. The data-set of 106 musical audio excerpts is processed by means of an auditory model and then divided into several spectral regions and metric levels. The resulting segments are described in terms of their musical properties, over which patterns of peak positions and their intensities are sought. A clustering algorithm is used to systematize the process of pattern detection. The results confirm previously reported anticipations of the third and fourth semiquavers in a beat. We also argue that these patterns of microtiming deviations interact with different profiles of intensities that change according to the metrical structure and spectral characteristics. In particular, we suggest two new findings: (i) a small delay of microtiming positions at the lower end of the spectrum on the first semiquaver of each beat and (ii) systematic forms of accelerando and ritardando at a microtiming level covering two-beat and four-beat phrases. The results demonstrate the importance of multidimensional interactions with timing aspects of music. However, more research is needed in order to find proper representations for rhythm and microtiming aspects in such contexts

Sugar industry waste for bioelectricity generation

Microbial fuel cells are presented as the promise of technology to generate electricity by using organic waste. In this research, molasses waste from Laredo Agroindustrial Company was used as fuel, as well as graphite and zinc electrodes, managing to build low-cost cells. It was possible to generate voltage and current peaks of 0.389 ± 0.021 V and 1.179 ± 0.079 mA, respectively. The cells showed that acid pH levels and conductivity values were around 100 mS/cm during the period of the highest bioelectricity generation. The maximum power density was 3.76 ± 0.62 W/ cm2 for a current density of 247.55 mA/cm2, showing a peak voltage of 0.459 ± 0.52 V. The yeasts showed a logarithmic phase up to day 25 reflecting an increase in cell growth. Microbial fuel cells are projected to be the most viable solution for organic waste and clean energy generation problems

Incorporation of biosynthesized silver nanoparticles in active biodegradable films of potato starch

En este trabajo se presenta el estudio del efecto de la incorporación de nanopartículas de plata biosintetizadas sobre las propiedades de películas biodegradables fabricadas a partir de almidón de papa 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 confirmó la integración de las nanopartículas de plata en películas biodegradables fabricadas a partir de almidón de papa confirmando los efectos en sus características físicas y propiedades activas en función del porcentaje de AgNp, las cuales pueden ser aprovechadas para la fabricación de materiales activos

Education can improve the negative perception of a threatened long-lived scavenging bird, the Andean condor

Human-wildlife conflicts currently represent one of the main conservation problems for wildlife species around the world. Vultures have serious conservation concerns, many of which are related to people's adverse perception about them due to the belief that they prey on livestock. Our aim was to assess local perception and the factors influencing people's perception of the largest scavenging bird in South America, the Andean condor. For this, we interviewed 112 people from Valle Fértil, San Juan province, a rural area of central west Argentina. Overall, people in the area mostly have an elementary education, and their most important activity is livestock rearing. The results showed that, in general, most people perceive the Andean condor as an injurious species and, in fact, some people recognize that they still kill condors. We identified two major factors that affect this perception, the education level of villagers and their relationship with livestock ranching. Our study suggests that conservation of condors and other similar scavengers depends on education programs designed to change the negative perception people have about them. Such programs should be particularly focused on ranchers since they are the ones who have the worst perception of these scavengers. We suggest that highlighting the central ecological role of scavengers and recovering their cultural value would be fundamental to reverse their persecution and their negative perception by people.Fil: Cailly Arnulphi, Verónica Beatríz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Borghi, Carlos Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

Refrigerated warehouses as intelligent hubs to integrate renewable energy in industrial food refrigeration and to enhance power grid sustainability

© 2016 Elsevier LtdBackground Independence from fossil fuels, energy diversification, decarbonisation and energy efficiency are key prerequisites to make a national, regional or continental economy competitive in the global marketplace. As Europe is about to generate 20% of its energy demand from Renewable Energy Sources (RES) by 2020, adequate RES integration and renewable energy storage throughout the entire food cold chain must properly be addressed. Scope and approach Refrigerated warehouses for chilled and frozen foods are large energy consumers and account for a significant portion of the global energy demand. Nevertheless, the opportunity for RES integration in the energy supply of large food storage facilities is often neglected. In situ power generation using RES permits capture of a large portion of virtually free energy, thereby reducing dramatically the running costs and carbon footprint, while enhancing the economic competitiveness. In that context, there exist promising engineering solutions to exploit various renewables in the food preservation sector, in combination with the emerging sustainability-enhancing technology of Cryogenic Energy Storage (CES). Key findings and conclusions Substantial research endeavours are driven by the noble objective to turn the Europe's Energy Union into the world's number one in renewable energies. Integrating RES, in synchrony with CES development and proper control, is capable of both strengthening the food refrigeration sector and improving dramatically the power grid balance and energy system sustainability. Hence, this article aims to familiarise stakeholders of the European and global food preservation industry with state-of-the-art knowledge, know-how, opportunities and professional achievements in the concerned field