Recovery of Water and Salts from Hyper-Saline Mine Water using Freeze Crystallization

In the mining industry, usage of large volumes of water enables mines to conduct multiple processes within one location. Hypersaline brine waters exit the processes of the mine to be utilized for other roles; some of these roles include leaching, recirculation, and extraction operations. These waters are highly concentrated with salt components and are released to different sections of the mine. The salts of highest concentration in the brine are aluminum sulfate and magnesium sulfate heptahydrate, along with low concentrations of many other elements. There are multiple ways to recover purified water from the brine solution: freeze crystallization, evaporative processes, and reverse osmosis. The impacted water in the mine must be purified to meet regulations before being discharged. Freeze crystallization is a process which can be used to recover purified water. For this task, the sponsor (Freeport-McMoRan), has requested an evaluation of a freeze crystallization process for recovering 50% of the impacted mine waters. Multiple effect evaporation and reverse osmosis were also investigated as, potentially, less costly processes. The Freezerbacks researched, designed, and economically evaluated a full-scale freeze crystallization process as well as two alternative full-scale processes: 5 stage multiple effect evaporation and reverse osmosis. All three processes were designed to treat hyper-saline mine water that was sent into evaporation pond systems. These systems were designed for Freeport-McMoRan’s mines that need to treat impacted water

Expanding engineering tools for Cupriavidus necator H16 to convert waste stream into useful chemicals via rational design and evolutionary engineering approaches

Cupriavidus necator H16 is a chemolithoautotrophic Gram-negative bacterium that belongs to the class of -proteobacteria. In recent years, it has attracted the biotechnological attention as a cell factory to produce value-added chemicals. Thus, a need for expanding engineering tools for chemical production in C. necator H16 has emerged. In order to use C. necator H16 as a cell factory, mainly two different engineering strategies are reviewed in this work: rational design engineering and evolutionary engineering. Aim: The overall aim of the study is to engineer C. necator H16 with rational design and evolutionary engineering tools to explore the biotechnological potentials of the strain and fine-tune the properties of C. necator H16 for chemical production using waste stream as a feedstock. Thesis content: In Chapter 1, literature review about C. necator H16 was compiled to understand the natural metabolism of the strain and to analyse its different biomanufacturing potentials, as well as engineering strategies used for chemical production in C. necator H16 and other related microorganisms, afterwards, in Chapter 2 the development of an optimised transformation method and a synthetic biology toolbox for C. necator H16 was developed to design robust strains of C. necator H16. Once the synthetic biology toolbox was tailored for C. necator H16, in Chapter 3, the synthetic biology toolbox was tested for the expression of two clusters of genes as well as possibly obtain bioproducts from the expression of these. Then, in Chapter 4, evolutionary engineering tools were optimised to engineer C. necator H16, the evolutionary engineering tool used was directed evolution via random mutagenesis, where an optimised protocol for random mutagenesis with a chemical mutagen for C. necator H16 was optimised and used to try to understand the biotin biosynthesis pathway of C. necator H16, which could furtherly be used for chemical production. In Chapter 5, the knowledge and strategies studied in previous chapters and proven to work in C. necator H16 supported the approaches selected to construct recombinant and evolved strains of C. necator H16 for chemical production (bioplastics) using waste stream (crude glycerol) as a feedstock. Chapter 6 highlights the general discussions, results, future work and perspectives of this PhD work

Understanding the Detection of View Fraud in Video Content Portals

While substantial effort has been devoted to understand fraudulent activity in traditional online advertising (search and banner), more recent forms such as video ads have received little attention. The understanding and identification of fraudulent activity (i.e., fake views) in video ads for advertisers, is complicated as they rely exclusively on the detection mechanisms deployed by video hosting portals. In this context, the development of independent tools able to monitor and audit the fidelity of these systems are missing today and needed by both industry and regulators. In this paper we present a first set of tools to serve this purpose. Using our tools, we evaluate the performance of the audit systems of five major online video portals. Our results reveal that YouTube's detection system significantly outperforms all the others. Despite this, a systematic evaluation indicates that it may still be susceptible to simple attacks. Furthermore, we find that YouTube penalizes its videos' public and monetized view counters differently, the former being more aggressive. This means that views identified as fake and discounted from the public view counter are still monetized. We speculate that even though YouTube's policy puts in lots of effort to compensate users after an attack is discovered, this practice places the burden of the risk on the advertisers, who pay to get their ads displayed.Comment: To appear in WWW 2016, Montr\'eal, Qu\'ebec, Canada. Please cite the conference version of this pape

Social power of preadolescent children on influence in their mothers’ purchasing behavior: initial study in Peruvian toy stores

Purpose: This paper aims to investigate the relationship between legitimate and expert social power types of preadolescent children on the influence perception in their mothers’ purchasing behavior in Peruvian toy stores. The literature review takes into consideration the concepts of social power and the influence on family behavior to then focus on social power within family behavior with the purpose of mainly developing four hypotheses regarding purchasing behavior. Design/methodology/approach: The methodology followed a non-experimental transversal correlational-causal design. A pilot sample size of 67 cases was used. The sample was based on an objective population of Peruvian mothers of families that live in northern Lima and that go to purchase toys to major shopping centers with their children aged 8-11 years. Findings: The results show that the expert social power, as well as the legitimate social power, has a strong relationship. In addition, both social powers have an impact on the influence perception in purchasing child-mother, but not on the influence perception in purchasing mother-child. Moreover, the test of moderation of the expenditure level on toy purchases did not have an effect on the context that was studied. Originality/value: The contribution shows that important changes are happening in the consumption behavior on the aspect of children influencing mothers, and that for Latin American contexts, the level of expenditure still does not crucially affect the causality demonstrated.Objetivo: Este trabajo tiene como objetivo investigar la relación entre tipos de poder social legítimo y experto de niños preadolescentes sobre la percepción de influencia en el comportamiento de compra de sus madres en las jugueterías peruanas. La revisión de la literatura toma en consideración los conceptos de poder social y la influencia en el comportamiento familiar para luego enfocarse en el poder social dentro del comportamiento familiar con el propósito de desarrollar principalmente cuatro hipótesis sobre el comportamiento adquisitivo. Diseño / metodología / enfoque: La metodología siguió un diseño correlacional-causal transversal no experimental. Se utilizó un tamaño de muestra piloto de 67 casos. La muestra se basó en una población objetiva de madres peruanas de familias que viven en el norte de Lima y que acuden a comprar juguetes a los principales centros comerciales con sus hijos de 8 a 11 años. Recomendaciones: Los resultados muestran que el poder social experto, así como el poder social legítimo, tienen una fuerte relación. Además, ambos poderes sociales inciden en la percepción de influencia en la compra hijo-madre, pero no en la percepción de influencia en la compra madre-hijo. Además, la prueba de moderación del nivel de gasto en compra de juguetes no tuvo efecto en el contexto estudiado. Originalidad / valor: El aporte muestra que se están produciendo cambios importantes en el comportamiento de consumo en el aspecto de los niños que influyen en las madres, y que para los contextos latinoamericanos, el nivel de gasto aún no afecta de manera crucial la causalidad demostrada

Preparation of quantum dots hydrogel nanocomposites with improved cytotoxicity

Nanocomposites are materials with unique properties and a wide range of applications. The combination of different nanostructures with traditional materials gives a variety of possibilities that should be analyzed. Especially, functional fluorescent semiconductor quantum dots (QDs) embedded in polymeric matrices have shown promising fluorescence and biocompatibility properties. These hybrid materials can be used in medical applications such as biodiagnostic and bioimaging. In this study, two hydrogels, one of polyethylene glycol diacrylate (PEGDA) and other of polyacrylamide (PAAm), were prepared with quantum dots of CdTe (4 nm of diameter) and characterized. The aim of this research was to analyze the optical properties of the nanocomposites and their cell viability. QDs nanocomposites were fabricated by a free radical polymerization process. The optical studies showed that the nanocomposites have well defined properties of fluorescence. To study the biocompatibility of the nanocomposites, metastatic B16f10 cell line were used and MTT assay was performed. The nanocomposites had a significant improved cell viability compared with QDs solutions

Changes in Teaching During the Covid-19 Pandemic

During the confinement derived from the Covid-19 pandemic, many aspects of life changed; including, formal and informal economic activities were suspended. However, education could not be stopped, and for this reason, teachers found themselves in need of including ICT as part of their teaching strategies; seeing themselves in the obligation to modify their training practices. This paper analyzes the changes in teacher training during the confinement due to the pandemic. For this, a survey was made to teachers of the University Center of the Valleys of the University of Guadalajara, in order to rescue their experiences when training during this period. It would seem that the virtual training that was beginning to emerge, and was not yet very well accepted, came to satisfy or complement the learning needs, including disciplinary update courses, which were taught using technologies such as ClassRoom©, Youtube® transmissions, videoconferences via Meet© and Zoom®, which opened a wide panorama in terms of teacher training

Restoration and rehabilitation of degraded land in arid and semiarid environments: Editorial

info:eu-repo/semantics/publishedVersio

Osteogenic effects of simvastatin-loaded mesoporous titania thin films

The use of statins in the field of bone regeneration is under current investigation due to the existing demand for non-toxic anabolic agents capable of enhancing bone formation in cases of substantial loss. Simvastatin, a coenzyme currently prescribed in clinics to inhibit cholesterol biosynthesis, has been proven to promote osteogenic differentiation by stimulating bone formation and inhibiting osteoclasts activity. We present the loading of simvastatin in mesoporous TiO2 thin films toward combining the pro-osteogenic properties of this molecule with the demonstrated bioactivity of titania. TiO2 thin films processing and characterization were carried out, as well as evaluation of MC3T3-E1 pre-osteoblasts viability when directly incubated with different concentrations of simvastatin, followed by the analysis of osteogenic activity promoted by simvastatin upon loading in the thin films. The accessible porosity of 36% quantified on the 95 ± 5 nm thick mesoporous thin films, together with pore diameters of 5.5 nm, necks between pores of 2.8 nm and interpore distances of 12 ± 2 nm allow the loading of the simvastatin molecule, as confirmed by FTIR spectroscopy. Simvastatin was found to promote MC3T3-E1 pre-osteoblasts viability at concentrations ≤0.01 g l−1, with a cytotoxicity threshold of 0.05 g l−1. We additionally found that film loadings with 0.001 g l−1 simvastatin promotes statistically higher MC3T3-E1 pre-osteoblast proliferation whereas a higher concentration of 0.01 g l−1 leads to statistically higher osteogenic activity (ALP synthesis), after 21 days of incubation, as compared to unloaded films. These results demonstrate the potential of simvastatin local administration based on bioactive mesoporous thin films to promote pro-osteogenic properties. By focusing this strategy on the coating of metallic prostheses, the supply of simvastatin to the target tissue can be favored and risks of systemic side effects will be reduced while enhancing the osteointegration of the implants.Fil: Lopez Alvarez, Miriam. Universidad de Vigo; EspañaFil: López Puente, Vanesa. Universidad de Vigo; EspañaFil: Rodriguez Valencia, Cosme. Universidad de Vigo; EspañaFil: Angelome, Paula Cecilia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liz Marzan, Luis M. Ikerbasque; EspañaFil: Serra, Julia. Universidad de Vigo; EspañaFil: Pastoriza Santos, Isabel. Universidad de Vigo; EspañaFil: Gonzalez, Pio. Universidad de Vigo; Españ