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Research Publications (Applied Sciences)

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Browsing Research Publications (Applied Sciences) by SDG "SDG14"

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    Biodiesel from microalgae: A critical evaluation from laboratory to large scale production
    (Elsevier, 2013) Rawat, Ismail; Ranjith Kumar, R.; Mutanda, Taurai; Bux, Faizal
    The economically significant production of carbon-neutral biodiesel from microalgae has been hailed as the ultimate alternative to depleting resources of petro-diesel due to its high cellular concentration of lip-ids, resources and economic sustainability and overall potential advantages over other sources of biofu-els. Pertinent questions however need to be answered on the commercial viability of large scale production of biodiesel from microalgae. Vital steps need to be critically analysed at each stage. Isolation of microalgae should be based on the question of whether marine or freshwater microalgae, cultures from collections or indigenous wild types are best suited for large scale production. Furthermore, the determination of initial sampling points play a pivotal role in the determination of strain selection as well as strain viability. The screening process should identify, purify and select lipid producing strains. Are natural strains or stressed strains higher in lipid productivity? The synergistic interactions that occur nat-urally between algae and other microorganisms cannot be ignored. A lot of literature is available on the downstream processing of microalgae but a few reports are available on the upstream processing of mic-roalgae for biomass and lipid production for biodiesel production. We present in this review an empirical and critical analysis on the potential of translating research findings from laboratory scale trials to full scale application. The move from laboratory to large scale microalgal cultivation requires careful plan-ning. It is imperative to do extensive pre-pilot demonstration trials and formulate a suitable trajectory for possible data extrapolation for large scale experimental designs. The pros and cons of the two widely used methods for growing microalgae by photobioreactors or open raceway ponds are discussed in detail. In addition, current methods for biomass harvesting and lipid extraction are critically evaluated. This would be novel approach to economical biodiesel production from microalgae in the near future. Glob-ally, microalgae are largest biomass producers having higher neutral lipid content outcompeting terres-trial plants for biofuel production. However, the viscosities of microalgal oils are usually higher than that of petroleum diesel.
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    Green synthesis of gold nanoparticles using marine algae and evaluation of their catalytic activity
    (SpringerOpen, 2016) Ramakrishna, M.; Babu, Dandamudi Rajesh; Gengan, Robert Moonsamy; Chandra, S.; Rao, G. Nageswara
    The hazardous effects of current nanoparticle synthesis methods have steered researchers to focus on developing newer eco-friendly methods for synthesizing nanoparticles using non-toxic chemicals. Owing to the diverse applications of nanoparticles in various fields such as catalysis, medicine, diagnostics, and sensors, several novel green approaches have been explored for synthesiz-ing nanoparticles using different natural sources such as plants, algae, bacteria, and fungi. Hence, in the present work, a green method for the synthesis of gold nanoparti-cles (AuNPs) under ambient conditions using aqueous extracts of marine brown algae is reported and the syn-thesized AuNPs were evaluated for their catalytic effi-ciency. The aqueous extracts of algae comprise reducing as well as capping agents required for the formation of AuNPs. The Fourier transform infrared spectra of the extracts revealed the presence of compounds having hydroxyl groups that are largely responsible for the reduction of auric chloride to AuNPs at room temperature. Results from high-resolution transmission electron micro-scopy and dynamic light scattering studies suggested that most of the biosynthesized AuNPs are nearly spherical in shape with an average size in the range of 27–35 nm. High negative values of zeta potential measurement confirmed the stability of AuNPs. Moreover, the reduction kinetics of AuNPs studied by UV–visible spectrophotometry showed that they have good catalytic efficiency in the degradation of dyes as well as reduction of nitro compounds in the presence of sodium borohydride as reducing agent. This simple process for the biosynthesis of gold nanoparticles is rapid, cost-effective and eco-friendly. The formation of AuNPs was observed with the change of pale yellow gold solution to ruby red color of gold nanoparticles and con-firmed by surface plasmon spectra using UV–visible spectroscopy. Nanoparticles synthesized through such environmentally benign routes can be used for synthesizing many other metal nanoparticles as well as for a wide range of biomedical applications, for commercial production on a large scale and also can be used as efficient catalysts for different organic reactions.
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    Matching interaction design principles and integrated navigation systems in an electronic classroom
    (Faculty of Maritime Studies Split, 2020-04) Bauk, Sanja; Fajardo-Flores, Silvia
    This article deals with cross-cultural and cross-disciplinary virtual engagement aimed to match human-computer interaction design principles and contemporary integrated navigation information systems. As interaction design principles ten general principles - heuristics are used, and as examples of contemporary navigation information systems, chart Radio Detection (or Direction) and Ranging (RADAR) device and Electronic Chart Display and Information System (ECDIS) are used. This cross-disciplinary research has been achieved through a Collaborative Online International Learning (COIL) project by Durban University of Technology (DUT) in South Africa and University of Colima (UoC) in Mexico. Namely, the students from both sides guided by their lecturers have been engaged in analyzing today’s most frequently used marine navigational aids from the perspective of their reliability and user centeredness. The complexity of the systems and the lack of standards are observed as main problems when it comes to marine information systems effectiveness and their user centeredness.