1,721,047 research outputs found
Electrochemical and photocatalytic oxidation of organic pollutants from waste water using efficient nano-catalytic coatings prepared by electrodeposition
No full textWastewater from the textile industry is considered to be one of the most pollutant effluents due to its toxic organic colourants content being strongly resistant to oxidation. When these substances are directly discharged into rivers and sea they persist for long periods causing environmental and aesthetic problems together with high health risks to living organisms. The main goal of this research is to study the oxidation of different textile dyes and organic pollutants, in particular reactive black-5 (RB-5) and methylene blue (MB) dyes using different nano catalytic coatings. A 3D flexible titanium felt electrode was anodized for growing TiO2 nanotubes and further decorated with PbO2 subsequently employed for anodic electrochemical and photochemical treatment of wastewater containing RB-5 dye. Similarly, reticulated vitreous carbon (RVC)surfaces were decorated with a layer of PbO2 and titanate nanosheets by anodic electrophoretic deposition, with subsequent structural and morphological characterization using FESEM and Raman spectroscopy. The TiNS/PbO2/RVC electrode has titanium anatase phase which was obtained by annealing at 450°C for 60 min in air. The structure revealed a well-specified, microporous structure with hydrophilic properties along the length and thickness of the RVC struts. Electrochemical and photocatalytic behaviour of the composite assisted the decolourisation of organic RB-5 dye in aqueous solution; on one hand • OH radicals were electrochemically produced via TiNS/PbO2/RVC anode composite coating and the photocatalytic decolourisation use the synergetic photocatalytic activity associated with the holes and free electron acceptors generated during UV irradiation experiments. Another objective of this thesis is the synthesis of efficient nanotubular titanates (TiNTs) coatings over the surface of the RVC substrate to make the organic oxidation more efficient. Titanate nanotubes (TiNTs) were deposited over the surface of a 100 pores per inch (ppi) RVC by anodic electrophoresis. The photocatalytic characteristics of the coating were enhanced by annealing at 450 °C for 60 min in air. A preliminary evaluation of novel TiNT/RVC coatings demonstrated to be useful for the photocatalytic colour removal of MB dye. In addition, a zinc metal plate was electrochemically anodised to produce ZnO nanowires. The selected operational conditions together a subsequent dip-coating process of the anodised ZnO surface in a TiO2 containing solution, produced a core-shell coating. A further electrochemical deposition of PbO2 over the core-shell produced a hybrid core (ZnO-TiO2)-shell (PbO2) coatings. The electrochemical and photocatalytic behaviour of the coatings were analysed by employing them to remove RB-5 dye (1 × 10-5 mol dm-3 ). The nano-coatings are low cost option for the oxidation of textile dyes and improved removal of RB-5 and MB dyes at a removal efficiency of ≈99 %
MANET Cluster Optimization Using ILP/SAT Techniques
No full textA Master of Science thesis in Computer Engineering by Syed Zohaib Hussain Zahidi entitled, "Manet Cluster Optimization Using ILP/SAT Techniques," submitted in January 2012. Thesis advisor is Dr. Fadi Ahmed Aloul and co-advisor is Dr. Assim Sagahyroon. Available are both soft and hard copies of the thesis.In recent years, there have been several improvements in the performance of Integer Linear Programming (ILP) and Boolean Satisfiability (SAT) solvers. These improvements have encouraged the modeling of complex engineering problems as ILP problems. These engineering problems are diverse in nature and include genetics, optimization of power consumption, scheduling, cryptography, and more. One such problem is the "-clustering problem' in Mobile Ad-Hoc Networks (MANETs). The clustering problem in MANETs consists of selecting the most suitable nodes of a given MANET topology as clusterheads and ensuring that regular nodes are connected to clusterheads in such a way that the network lifetime is maximized. This thesis focuses on assessing the performance of state-of-the art generic ILP and 0-1 SAT-based ILP solvers in solving ILP formulations of the clustering problem. The thesis consists of four parts. The first part of this thesis consists of improving the existing ILP formulations of the clustering problem. The second part involves enhancing the ILP formulation of the clustering problem through the addition of intra-cluster communication, coverage constraints and multihop links. The third part focuses on the development of an improved tool to enable conversion of user-created on-screen topologies to an ILP formulation. The fourth and final part of this thesis is the detailed performance comparison of a selected set of Generic ILP and 0-1 SAT-based ILP solvers in solving the improved ILP formulations of the clustering problem generated using the tool. The results obtained indicate that from our selected set of solvers, generic ILP solvers are able to handle relatively large scale MANET topologies, while 0-1 SAT-based ILP solvers are the fastest, for small scale networks. For small scale networks the proposed ILP formulations, such as the Star-Ring base model, together with the high performance solvers would be suitable for use in real-world environments. However for large scale networks, as the time to cluster the network grows exponentially, the solvers will be unable to cluster the network in accordance with the demands of a real-world environment.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Data for the paper entitled: Decolorization of Reactive Black-5 at an RVC substrate decorated with PbO2/ TiO2 nanosheets prepared by anodic electrodeposition
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S.Z.J. Zaidi, C. Harito, F.C. Walsh, C. Ponce de León (2018). Decolorization of Reactive Black-5 at an RVC substrate decorated with PbO2/ TiO2 nanosheets prepared by anodic electrodeposition. Journal of Solid State Electrochemistry
Reticulated vitreous carbon (RVC) substrates were coated with a composite of PbO2 and titanate nanosheets (TiNS) by anodic electrophoretic deposition. The structure and morphological characteristics of the coating were evaluated by Field Emission Scanning Electron Microscopy (FESEM) and Raman spectroscopy. The TiNS/PbO2/RVC coating contained the anatase phase and showed a well-defined, microporous morphology with hydrophilic character along the length and thickness of the RVC struts. Electrochemical and photocatalytic activity of the coatings facilitated RB-5 dye degradation as a model organic pollutant in wastewater. The electrochemical decolorization involves the generation of hydroxyl free radicals over the TiNS/PbO2/RVC anode composite surface whereas photocatalytic decolorization was driven by the synergetic photocatalytic effect imparted by the photoinduced holes and free electron acceptors. The photocatalytic properties of the TiNS/PbO2 coating were achieved by calcination at 450 °C for 60 minutes in air which converted the titanate phase to anatase and modified its surface area. This enabled 98 % electrochemical decolorization of the RB-5 dye solution (measured by visible absorption at 597 nm) in a time of 60 minutes.
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Decolourisation of reactive black-5 at an RVC substrate decorated with PbO2/ TiO2 nanosheets prepared by anodic electrodeposition
No full textReticulated vitreous carbon (RVC) substrates were coated with a composite of PbO2 and titanate nanosheets (TiNS) by electrophoresis. The structure and morphological characteristics of the coating were evaluated by field emission scanning electron microscopy (FESEM) and Raman spectroscopy. The TiNS/PbO2/RVC coating contained the anatase phase and showed a well-defined, microporous morphology with hydrophilic character along the length and thickness of the RVC struts. Electrochemical and photocatalytic activity of the coatings facilitated RB-5 dye degradation as a model organic pollutant in wastewater. The electrochemical decolourisation involves the generation of hydroxyl free radicals over the TiNS/PbO2/RVC anode composite surface whereas photocatalytic decolourisation was driven by the synergetic photocatalytic effect imparted by the photoinduced holes and free electron acceptors. The photocatalytic properties of the TiNS/PbO2 coating were achieved by calcination at 450 °C for 60 minutes in air which converted the titanate phase to anatase and modified its surface area. This enabled 98% decolourisation of the RB-5 dye solution (measured by visible absorption at 597 nm) in a time of 60 minutes
A review of biodegradable natural polymer-based nanoparticles for drug delivery applications
Get PDFBiodegradable natural polymers have been investigated extensively as the best choice for encapsulation and delivery of drugs. The research has attracted remarkable attention in the pharmaceutical industry. The shortcomings of conventional dosage systems, along with modified and targeted drug delivery methods, are addressed by using polymers with improved bioavailability, biocompatibility, and lower toxicity. Therefore, nanomedicines are now considered to be an innovative type of medication. This review critically examines the use of natural biodegradable polymers and their drug delivery systems for local or targeted and controlled/sustained drug release against fatal diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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