34 research outputs found
Use of Biochar from Rice Husk Pyrolysis: Part A: Recovery as an Adsorbent in the Removal of Emerging Compounds
[EN] One of the main products of pyrolysis is char. For the better performance and improvement of its physicochemical properties, it is necessary to make temperature changes. In this study, different temperatures have been tested for the pyrolysis of rice husk, and the biochar obtained from the process went through an evaluation to test its yield in the removal of emerging compounds such as azithromycin (AZT) and erythromycin (ERY). For this, pyrolysis of rice husk has been carried out at temperatures of 450, 500, 550, and 600 degrees C, and the biochars have been characterized by ultimate analysis and proximate analysis, as well as specific surface area tests. Then, different adsorption tests have been carried out with a 200 mg L-1 drug (AZT and ERY) solution prepared in the laboratory. All biochars have been found to present removal percentages higher than 95%. Therefore, obtaining biochar from rice husk at any temperature and using it in the removal of high-molecular-weight compounds are quite suitable.This work was carried out with financial support from the Department of Civil and Environmental Engineering at Universidad de los Andes. This publication was partially made possible by the call for proposals CI-0120: "Publish your new knowledge or expose your new creations" from the Office Vice President for Research and Creation at Universidad de los Andes
Evolución del volcanismo submarino en el estrecho Bransfield: Relación de las emanaciones hidrotermales con la biodiversidad y el cambio climático - [Boletín M 1]
Las expediciones científicas peruanas a la Antártida se realizan desde el año 1988, fecha en la que se realizó la Primera Expedición Científica Peruana a la Antártida – ANTAR I. Esta expedición se realizó a bordo del BIC Humboldt. El Ingemmet, como ente rector de las geociencias en nuestro país, participa desde la segunda expedición antártica, primero como apoyo técnico y geológico en Punta Crepín, isla Rey Jorge, para la construcción y ampliación de la Estación Científica Machu Picchu. A partir del período 2018-2019 y con arribo de la moderna plataforma BAP Carrasco, se empiezan a desarrollar proyectos de investigación multidisciplinarios en geología marina y antártica, con colaboración de instituciones nacionales e internacionales. Siendo así, el Ingemmet, para el desarrollo de la XXVII Expedición Científica Peruana a la Antártida – ANTAR XXVII, presenta un proyecto multidisciplinario que busca relacionar el impacto de la geología en la distribución y biodiversidad del fondo marino Este proyecto se titula “Evolución del Volcanismo Submarino en el estrecho de Bransfield: Relación de las Emanaciones Hidrotermales con la Biodiversidad y el Cambio Climático” y se desarrolla en coordinación y cooperación entre el Instituto Geológico Minero y Metalúrgico (Ingemmet), la universidad Científica del Sur (Científica – Perú), la Facultad de Ciencias, Universidad de la República (Uruguay) y el Instituto de Investigaciones Marinas y Costeras José Benito Vives de Andréis (Invemar - Colombia). Este proyecto busca caracterizar la morfología y composición de los volcanes y emanaciones hidrotermales submarinas, así como identificar las comunidades biológicas, microbiológicas y características medioambientales del estrecho de Bransfield, Antártida. Siendo así, las actividades para cumplir este objetivo se desarrollan a través de la realización de cruceros de investigación geológica-oceanográfica, que se denominan cruceros multinacionales ORCA. La ejecución de las actividades se realiza a bordo de la plataforma científica BAP Carrasco, y son coordinadas por la Dirección de Asuntos Antárticos del Ministerio de Relaciones Exteriores. El crucero tuvo una duración de 15 días efectivos de trabajo y abarco 4 áreas de recolección de información: bahía Collins, bahía Almirantazgo, bahía Esperanza y estrecho de Bransfield. Así también, comprendió el levantamiento de información geológica, oceanográfica, biológica, microbiológica, radiológica y de microplásticos entre la isla Rey Jorge y la península antártica. El presente boletín tiene por objetivo mostrar toda la información recopilada durante el desarrollo del Crucero ORCA I, para que sea de disponibilidad de la comunidad científica
"Bioinformática con Ñ v1.0": a collaborative project of young Spanish scientists to write a complete book about Bioinformatics
Here we present a project aiming to provide specialized educational bibliography on Bioinformatics for Spanish speakers. The idea of writing a book in Spanish language covering the most important topics in the field of Bioinformatics was born in the XIth Spanish Symposium on Bioinformatics in Barcelona two years ago. Different scientists have been involved in the project, from senior scientists to PhD students from different countries. The book intends to be the beginning of an open project, where all the chapters are susceptible of being updated and new topics can be incorporated in future versions. Current book version can be accessed online at http://goo.gl/UYG0o7.Peer Reviewe
Microbially Synthesized Polymer-Metal Nanoparticles Composites as Promising Wound Dressings to Overcome Methicillin-Resistance <i>Staphylococcus aureus</i> Infections
Antimicrobial resistance has been declared one of the top 10 global public health threats. Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of recurring skin and soft tissue infections in patients with chronic skin conditions such as diabetic foot infections, making the treatment of the ulcers challenging. Wound dressings combined with metal nanoparticles have been suggested to prevent and treat MRSA-infected wounds. However, these particles are commonly synthesized by chemical approaches. In this study, we developed bio-based silver (Bio-AgNPs) and copper oxide nanoparticles (CuONPs) polymer composites using a microbially produced polyester from the Polyhydroxyalkanoates (PHAs) family. Poly(3-hydroxyoctanoate)-co-(3-hydroxyhexanoate) (PHO) was synthesized by Pseudomonas putida and functionalized in-situ with Bio-AgNPs or ex-situ with CuONPs. PHO-CuONPs films did not inhibit MRSA growth, while a reduction of 6.0 log CFU/mL was achieved with PHO-Bio-AgNPs synthesized from silver nitrate (AgNO3) solution at 3.5 mM. Exposure of human fibroblast cells (HFF-1) to the bioactive films did not induce notable cytotoxicity and genotoxicity, as seen by a viability higher than 79% and no significant changes in basal DNA damage. However, exposure to PHO-Bio-AgNPs induced oxidative DNA damage in HFF-1 cells. No hemolytic potential was observed, while platelet aggregation was promoted and desired for wound healing. Here we demonstrate the biosynthesis of polymer-nanoparticle composites and their potential as bioactive films for MRSA treatment
Scientometric Overview of Coffee By-Products and Their Applications
As coffee consumption is on the rise, and the global coffee production creates an excess of 23 million tons of waste per year, a revolutionary transition towards a circular economy via the transformation and valorization of the main by-products from its cultivation and preparation (Coffee Husk (CH), Coffee Pulp (CP), Coffee Silverskin (CS), and Spent Coffee Grounds (SCG)) is inspiring researchers around the world. The recent growth of scholarly publications in the field and the emerging applications of coffee by-products published in these scientific papers encourages a systematic review to identify the knowledge structure, research hotspots, and to discuss the challenges and future directions. This paper displays a comprehensive scientometric analysis based on 108 articles with a high level of influence in the field of coffee by-products and their applications. According to our analysis, the research in this field shows an explosive growth since 2017, clustered in five core applications: bioactive compounds, microbial transformation, environmental applications, biofuels from thermochemical processes, and construction materials
Synthesis of Micro- and Mesoporous Carbon Foams with Nanodispersed Metals for Adsorption and Catalysis Applications
This work focuses on carbon foams, whose peculiarity is a predominant open macroporous cellular network that can be provided with tailored texture and morphology by the modification of the preparation process. The goal was to obtain macroporous carbonaceous structures capable of being activated by following a simple thermo-foaming procedure using a few reagents. With this purpose in mind, carbon foams with different textural properties were synthesized from sucrose using two foaming processes: at atmospheric pressure and in a pressurized reactor. Iron and silver nitrates added to sucrose gave rise, after carbonization, to materials with iron oxides and elemental silver particles nano-dispersed in the carbon matrix and promoted microporosity in both cases and mesoporosity in the case of iron nitrate. Iron nitrate also catalyzes the graphitization of the carbon material during carbonization. All these findings show the potential of sucrose thermo-foaming process as a viable and sustainable path to produce versatile carbon materials, capable of being used in various applications
Synthesis of Micro- and Mesoporous Carbon Foams with Nanodispersed Metals for Adsorption and Catalysis Applications
This work focuses on carbon foams, whose peculiarity is a predominant open macroporous cellular network that can be provided with tailored texture and morphology by the modification of the preparation process. The goal was to obtain macroporous carbonaceous structures capable of being activated by following a simple thermo-foaming procedure using a few reagents. With this purpose in mind, carbon foams with different textural properties were synthesized from sucrose using two foaming processes: at atmospheric pressure and in a pressurized reactor. Iron and silver nitrates added to sucrose gave rise, after carbonization, to materials with iron oxides and elemental silver particles nano-dispersed in the carbon matrix and promoted microporosity in both cases and mesoporosity in the case of iron nitrate. Iron nitrate also catalyzes the graphitization of the carbon material during carbonization. All these findings show the potential of sucrose thermo-foaming process as a viable and sustainable path to produce versatile carbon materials, capable of being used in various applications
Calculation of the intrinsic solvation free energy profile of an ionic penetrant across a liquid/liquid interface with computer simulations
We introduce the novel concept of an intrinsic free energy profile, allowing one to remove the artificial smearing caused by thermal capillary waves, which renders difficulties for the calculation of free energy profiles across fluid interfaces in computer simulations. We apply this concept to the problem of a chloride ion crossing the interface between water and 1,2-dichloroethane and show that the present approach is able to reveal several important features of the free energy profile which are not detected with the usual, nonintrinsic calculations. Thus, in contrast to the nonintrinsic profile, a free energy barrier is found at the aqueous side of the (intrinsic) interface, which is attributed to the formation of a water “finger” the ion pulls with itself upon approaching the organic phase. Further, by the presence of a nonsampled region, the intrinsic free energy profile clearly indicates the coextraction of the first hydration shell water molecules of the ion when entering the organic phase
Measurement of charged jet suppression in Pb-Pb collisions at √sNN = 2.76 TeV
A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at sNN−−−√=2.76 TeV is reported. Jets are reconstructed from charged particles using the anti-kT jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudo-rapidity |η|<0.5. The transverse momentum pT of charged particles is measured down to 0.15 GeV/c which gives access to the low pT fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R=0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high pT leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R=0.2 and R=0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R<0.3.