406 research outputs found
Automating the determination of wave speed using the pu-loop method
No full textThe PU-loop (pressure-velocity loop) is a method for determining wave speed and relies on the linear relationship between the pressure and velocity in the absence of reflected waves. This linearity of the PU-loop during early systole, which is directly related to wave speed, has always been established by eye. This paper presents a new technique that establishes this linearity and thus determining wave speed online. Pressure and flow were measured in the ascending aorta of 11 anesthetised dogs. The slope of the PU-loop, indicating wave speed was determined by eye and by using the new technique. The difference between the slopes of the two methods is in the order of 3%. The new technique is convenient and allows for the online assessment of wave speed, which could be used as a bedside tool for the assessment of arterial compliance
The Pherobase
No full textThe Pherobase was developed by Dr. Ashraf El-Sayed, a research scientist at HortResearch in New Zealand, with the primary objective of providing "coverage of the literature published on chemical communication in insects." The Pherobase is intended for use by both scientific and non-scientific communities and currently contains "over 10000 entries, around 3000 molecules, and over 32000 static html pages that make it the world's largest database of behavior modifying chemicals." The site contains multiple Insect indices for such categories as Order, Family A-Z, and Species; References indices such as Discovery by Author, Discovery by Year, and References A-Z; and indices for Compounds, Compounds by Family, and Compounds by Genus. The site also contains a Contribution Form, and number of online forums relating to The Pherobase
A Methodology for Computational Architectural Design Based on Biological Principles
No full textBiomimicry, where nature is emulated as a basis for design, is a growing area of research in the fields of architecture and engineering. The widespread and practical application of biomimicry as a design approach remains however largely unrealized. A growing body of international research identifies various obstacles to the employment of biomimicry as an architectural design method. One barrier of particular note is the lack of a clear definition and methodology of the various approaches to biomimicry that designers can initially employ. This paper attempts to link biological principles with computational design in order to present a design methodology that aids interested architects within the preliminary design phase
Wettability of graphitic materials and their application in separation
Get PDFGraphitic carbon-water interaction or wettability of graphitic materials has received significant interest due to extraordinary thermal, physical, and electrical properties of different forms of graphitic carbon and influence of wettability in condensation, adhesion, separation, tribology, and adsorption. This important surface property is affected by change in topography, chemical heterogeneity, and surface charge. Graphene, which is a single atom thick sheet of graphitic carbon and building block of graphite, is an ideal model material to study this interaction. However, due to defect formation and contaminant adsorption from ambient atmosphere during the fabrication and use, wettability investigation using conventional means has been insufficient to investigate intrinsic wettability of graphene. Therefore, nanoscopic, microscopic and spectroscopic investigations under controlled conditions were performed to elucidate the relationships between surface defects, functionality, doping and wettability of graphene.
First study on wettability focuses on the influence of surface defects and functional groups of multilayer graphene, used as a model for graphene surface. The investigation reveals that airborne hydrophobic contaminants, adsorbed on graphene surface in the form of functional groups, can influence the wettability of graphene and graphite significantly (as high as 50˚ in water contact angle (WCA) change), and were found to be stable even under harsh conditions (i.e., at 1000 °C temperature, and in hydrofluoric acid). A WCA value of 45 ± 3° was measured for a clean highly oriented pyrolytic graphite (HOPG) surface, which can serve as the intrinsic WCA for multilayer graphene. In addition, WCA for multilayer graphene changed from ~5° to ~80° based on the surface functional groups and defects remaining and subsequent surface treatment/cleaning methods (i.e., thermal, physical, and chemical treatment). To demonstrate the stable hydrophobic characteristics of single layer graphene, hydrophobic graphene-hydrophilic SiO2 patterns were fabricated by a graphene micro-patterning technique developed in our laboratory. These micron scale patterns show dropwise condensation on graphene and film-wise condensation of SiO2.
In the second study, the doping-induced WCA tunability of graphene was investigated. As high as 13˚ modulation in WCA was observed for 300 meV chemical doping. For both n- and p-type doping using subsurface polyelectrolytes, graphene exhibits more hydrophilicity. Furthermore, adhesion force measurements using a hydrophobic self-assembled monolayer coated atomic force microscopy probe shows enhanced attraction towards undoped graphene, consistent with the wettability modulation. Such doping-induced wettability modulation is also achieved via subsurface metal doping. These measurements suggest for the first time that modulation of charge carrier density in graphene influences its wettability on the micro- and meso-scale. This tunable wettability due to doping opens the possibility of using graphene as a coating layer with tunable surface adhesion towards target chemicals/molecules.
Inspired by the fundamental studies on wettability of graphitic materials, their potential as separation membranes was evaluated for membrane distillation (MD) and a transformative water-energy cogeneration technology operating at supercritical conditions of water. Based on the finding that hydrophobic contaminant layer is stable, different graphitic carbon membranes (i.e., graphite, carbon nanotube (CNT), pyrolytic carbon, and graphene) were fabricated and evaluated for their potential to work as a separation device for both room and high temperature MD application. In particular, a new class of robust CNT membranes is developed using a scalable chemical vapor deposition method by direct growth of the CNT on a nickel alloy (Hastelloy) mesh with micrometer-sized openings. The developed membrane is superhydrophobic, corrosion and oxidation resistant (up to 500 °C), and shows similar desalination performance as a commercial Teflon MD membrane. These robust carbon membranes are reusable and expected to be less susceptible to fouling because of their superhydrophobic properties. Furthermore, if fouled, they can be regenerated by heating in air or using an acid wash.
This dissertation builds a framework to find a correlation between WCA of graphene with surface functional groups, doping level, and defects that can help design advanced graphitic carbon-based devices in the future. Moreover, development of graphitic carbon membranes suitable for high temperature applications opens the door of new possibilities for MD-based water desalination technology.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-05-01The student, Ali Ashraf, accepted the attached license on 2016-03-08 at 17:13.The student, Ali Ashraf, submitted this Dissertation for approval on 2016-03-08 at 17:38.This Dissertation was approved for publication on 2016-03-09 at 13:34.DSpace SAF Submission Ingestion Package generated from Vireo submission #9098 on 2016-07-07 at 14:16:04Made available in DSpace on 2016-07-07T21:14:19Z (GMT). No. of bitstreams: 17
ASHRAF-DISSERTATION-2016.pdf: 10348296 bytes, checksum: f0aa226d646ca18459106e8ceba2d948 (MD5)
Dissertation_Ali Ashraf.docx: 51612073 bytes, checksum: b9694d9ddd79e484d820ce0fd54ac645 (MD5)
LICENSE.txt: 4207 bytes, checksum: 4d3780cd99943b48f93e7495ca67a67c (MD5)
PROQUEST_LICENSE.txt: 4553 bytes, checksum: 4cfe53cd2c2b1388d49ee652ccc6fd07 (MD5)
RightsLink Printable License cell adhesion.pdf: 629901 bytes, checksum: f11057fc8e8de731d5c7d36f9ce1a42a (MD5)
RightsLink Printable License electrowetting.pdf: 1274015 bytes, checksum: faac06c965fef5f19441ea484aeb14a8 (MD5)
RightsLink Printable License for cnt growth mechanism.pdf: 1402676 bytes, checksum: 11e544500422208b69ef9a3aa51608a7 (MD5)
RightsLink Printable License for elsevier for cnt membrane.pdf: 2158644 bytes, checksum: 453e8267824d6a4794fa0a43c0601494 (MD5)
RightsLink Printable License nenad paper.pdf: 303820 bytes, checksum: ae89ab801f7b488d7df83c335c4912f4 (MD5)
RightsLink Printable License rsc microfluidics.pdf: 1283862 bytes, checksum: 68c3f4354741206a370671eaf20b1ef4 (MD5)
RightsLink Printable License water harvesting hump structure.pdf: 1451817 bytes, checksum: f6fb3bd0d9010ac0a802c5e30bf9bc47 (MD5)
RightsLink Printable License wiley E-SEM.pdf: 1454317 bytes, checksum: 4726dca9707a1ada3798772c313cc67b (MD5)
Rightslink by Copyright Clearance Center cryo-SEM.pdf: 188904 bytes, checksum: 90182194d54dc75a3fb7afe721abb3be (MD5)
Rightslink by Copyright Clearance Center langmuir permission.pdf: 274738 bytes, checksum: 99a3a153760eb0153d35d5cdca762a1c (MD5)
Rightslink by Copyright Clearance Center nano lett. role kinetics.pdf: 292318 bytes, checksum: 34623ca818a2be9bc2013587d7c21928 (MD5)
nature license for rise of graphene.pdf: 532687 bytes, checksum: b8b698278820e5fd466dc46cc861db31 (MD5)
science permission for atomically thin graphene.pdf: 2286315 bytes, checksum: 730d9643f8fd9e84ce8f30ed75b96397 (MD5)
Previous issue date: 2016-03-09Embargo set by: Seth Robbins for item 93223
Lift date: 2018-07-07T21:14:52Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 93223
Lift date: 2018-07-07T21:18:16Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 93223 on 2018-07-08T09:15:30Z
Publisher Correction: Synthesis of Saccharumoside-B analogue with potential of antiproliferative and pro-apoptotic activities (Scientific Reports, (2017), 7, 1, (8309), 10.1038/s41598-017-05832-w)
No full textIn the original version of this Article, Ghulam Md Ashraf was incorrectly affiliated with ‘Enzymoics and Novel Global Community Educational Foundation, Hebersham, NSW, Australia’. The correct affiliation is listed below. King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia. Additionally, within the Supplementary Information file originally published with this Article, authors Vijaya Rao Pidugu, Mohammad A. Kamal, Ghulam Md Ashraf, Vadim V. Tarasov, Vladimir N. Chubarev, Sergey G. Klochkov, George E. Barreto and Sergey O. Bachurin were omitted. These errors have now been corrected in the PDF and HTML versions of the Article, and in the accompanying Supplementary material. © 2020, The Author(s).Universidad Autónoma de Chil
Proposed network structures and combined adaptive algorithms for electrocardiogram signal denoising
No full textGeneralized Higher Derivations on Lie Ideals of Triangular Algebras
Get PDFAbstract
Let be the triangular algebra consisting of unital algebras A and B over a commutative ring R with identity 1 and M be a unital (A; B)-bimodule. An additive subgroup L of A is said to be a Lie ideal of A if [L;A] ⊆ L. A non-central square closed Lie ideal L of A is known as an admissible Lie ideal. The main result of the present paper states that under certain restrictions on A, every generalized Jordan triple higher derivation of L into A is a generalized higher derivation of L into A.</jats:p
Memory and Communication Profiling for Accelerator-Based Platforms
No full textThe growing demand of processing power is being satisfied mainly by an increase in the number of homogeneous and heterogeneous computing cores in a system. Efficient utilization of these architectures demands analysis of memory-access behaviour of applications and perform data-communication aware mapping of applications on these architectures. Appropriate tools are required to highlight memory-access patterns and provide detailed intra-application data-communication information to assist developers in porting existing sequential applications efficiently to these architectures. In this work, we present the design of an open-source tool which provides such a detailed profile for C/C++ applications. In contrast to prior work, our tool not only reports detailed information, but also generates this information with manageable overheads for realistic workloads. Comparison with the state-of-the-art shows that the proposed profiler has, on the average, an order of magnitude less overhead as compared to the state-of-the-art data-communication profilers for a wide range of benchmarks. The experimental results show that our proposed tool generated profiling information for image processing applications which assisted in achieving a speed-up of 6.14× and 2.75× for heterogeneous multi-core platforms containing an FPGA and a GPU as accelerators, respectively.Accepted Author ManuscriptComputer EngineeringQuantum & Computer Engineerin
Publisher Correction: SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway (Nature Microbiology, (2022), 7, 8, (1161-1179), 10.1038/s41564-022-01143-7)
No full text\ua9 The Author(s) 2022.In the version of this article initially published, the author affiliation information was incomplete, neglecting to note that Brian J. Willett, Joe Grove, Oscar A. MacLean, Craig Wilkie, Giuditta De Lorenzo, Wilhelm Furnon, Diego Cantoni, Sam Scott, Nicola Logan and Shirin Ashraf contributed equally and that John Haughney, David L. Robertson, Massimo Palmarini, Surajit Ray and Emma C. Thomson jointly supervised the work, as now indicated in the HTML and PDF versions of the article
Verses, subverses and subversions in contemporary postcolonial poetry : the arts of resistance in the works of Linton Kwesi Johnson and Lesego Rampolokeng
No full textIncludes bibliographical references (leaves 136-141).This dissertation seeks to analyse insubordination and resistance manifested in postcolonial and post-apartheid poetry as ways of subverting dominant Western discourses. More specifically, I focus my analysis on textual strategies of resistance in the poetry of Linton Kwesi Johnson and Lesego Rampolokeng. The syncretistic quality in the oeuvres of both poets is related to diaspora, hybridity and crealisation as forms of writ[h]ing against (neo)colonially-based hegemonic discourses. Postcolonial critiques at large will frame this analysis of strategies of domination and resistance, but some discussions from the domain of history, sociology and cultural studies may also enter the debate. In this regard there is a great variety of theories and arguments dealing with the contradictions and incongruities in the question of power relations interconnecting domination and resistance. This study is arranged in three pivotal debates. There is firstly an in-depth discussion of underpinning theories that deal with strategies of domination and resistance in the postcolonial domain This is a threefold task carried out by scrutinising (a) the origins of colonial discourse and its binarist tendencies, (b) the pitfalls of anticolonialist resistance based on dualistic opposites, and (c) the hybrid and insubordinate nature of resistance as an efficient alternative to transcend such binaries. Afterwards I seek to investigate how strategies of diasporic resistance and cultural hybridism employed in the poetry of Linton Kwesi Johnson can contribute to moving away from the limitations of dichotomies and also subvert hegemonic power. And finally, I look at crealisation, mockery and insubordination as strategies of resistance in the postapartheid poetry of Lesego Rampolokeng. Besides that, this project is concerned with the increasing importance of academic studies on postcolonial literatures. The present research aims therefore to analyse postcolonial and post-apartheid poems as strategic techniques to decentre dominant Western rhetoric that tries to naturalise inequalities and injustices in the relations between power holders and the powerless in both local and global contexts
- …
