1,720,953 research outputs found
Transparent Housing Design & Water Based Lubrication For Future Marine Drives
No full textThis thesis addresses lubrication challenges in marine transmissions through two complementary studies aimed at improving system transparency and evaluating sustainable lubrication alternatives. The primary objectives were to enable real-time visualization of oil flow in the IPS 10 transmission and to assess the viability of a water-based lubricant in the DPH driveline under realistic operating conditions. For the IPS 10 system, a transparent housing was designed using Accura ClearVue material to enable oil flow observation during operation. Four structural components were redesigned: the upper gear cover, upper gear housing, intermediate housing, and lower gear housing. These redesigns focused on removing non-essential features to improve visibility while preserving all functional interfaces, such as sealing surfaces, alignment features, and mounting points. Three mounting flange concepts were developed and evaluated using Finite Element Method (FEM) analysis: Half Circle, Simple Design, and Generative Design Extension (GDX). All concepts demonstrated structural integrity, with maximum stress values remaining below the allowable limit of 23 MPa, calculated with a safety factor of 2. The GDX concept exhibited the highest displacement value at 0.64 mm (compared to 0.31 mm for the Half Circle concept) but offered significant advantages in weight reduction and manufacturing cost due to its optimization for additive manufacturing. The final designs are complete and ready for selection and implementation based on Volvo Penta’s preferences. The second part of the thesis involved a lubricant comparison between a conventional synthetic oil (Mobil 75W140) and a water-based alternative (Transmission 150), developed in collaboration with Sustainalube. The test was conducted on a dedicated rig replicating realistic load and speed conditions. Prior to testing, the system was flushed with a cleaning fluid, and the water-based lubricant was subjected to a sequence of cycles at increasing speeds and torque levels. The lubricant performed satisfactorily at low to moderate loads, up to 30% of maximum torque. However, during the fifth cycle at 80% load (equivalent to 674 Nm), the test was terminated due to mechanical noise. Post-test inspection revealed metal-to-metal contact and visible gear wear, indicating failure of the lubricant film under high stress. Contributing factors included the water-based lubricant's lower pressure-viscosity coefficient (measured at <5 GPa⁻¹ compared to ~20 GPa⁻¹ for the synthetic oil), residual contamination from previous oils, and foaming issues resulting in air entrapment and seal leakage. This work contributes to a better understanding of lubrication mechanisms in marine transmissions and highlights the current limitations of water-based lubricants under high-load conditions. In parallel, a transparent gearbox housing was developed, offering a practical platform for future flow visualization and experimental research. Recommended future work includes improved surface cleaning protocols, further evaluation of influencing factors on water-based lubricant performance under high load, and consideration of their suitability for lower-load marine driveline applications as a step toward sustainable solutions.Detta examensarbete behandlar smörjningsutmaningar i marina transmissioner genom två kompletterande studier som syftar till att förbättra systeminsynen och utvärdera hållbara smörjalternativ. De huvudsakliga målen var att möjliggöra realtidsvisualisering av oljeflödet i IPS 10-transmissionen samt att undersöka möjligheten att använda ett vattenbaserat smörjmedel i DPH-drivlinan under realistiska driftförhållanden. För IPS 10-systemet konstruerades ett transparent hölje i materialet Accura ClearVue för att möjliggöra observation av oljeflödet under drift. Fyra strukturella komponenter omkonstruerades: övre växellådslocket, övre växelhuset, mellanväxelhuset och det nedre växelhuset. Omkonstruktionen fokuserade på att ta bort icke-kritiska detaljer för att förbättra sikten, samtidigt som alla funktionella gränssnitt – såsom tätningsytor, passningsfunktioner och monteringspunkter – bibehölls. Tre monteringsflänskoncept utvecklades och utvärderades med finita element-metoden (FEM): Halvcirkel, Enkel design och Generativ Design Extension (GDX). Samtliga koncept uppvisade strukturell hållfasthet, med maximala spänningsnivåer under den tillåtna gränsen på 23 MPa (beräknat med en säkerhetsfaktor på 2). GDX-konceptet uppvisade den största deformationen (0,64 mm jämfört med 0,31 mm för Halvcirkelkonceptet), men erbjöd tydliga fördelar vad gäller viktminskning och tillverkningskostnad tack vare sin optimering för additiv tillverkning. De slutgiltiga designerna är färdiga för val och implementering baserat på Volvo Pentas preferenser. Den andra delen av arbetet omfattade en smörjmedelsjämförelse mellan en konventionell syntetisk olja, Mobil 75W140, och ett vattenbaserat alternativ, Transmission 150, utvecklat i samarbete med Sustainalube. Testet genomfördes på en dedikerad testrigg som efterliknar realistiska belastnings- och hastighetsförhållanden. Innan testet inleddes spolades systemet med en rengöringsvätska, och det vattenbaserade smörjmedlet genomgick därefter en serie cykler med successivt ökande hastighet och vridmoment. Smörjmedlet presterade tillfredsställande vid låg till måttlig belastning upp till 30 procent av maximalt vridmoment. Under den femte cykeln, vid 80 procents belastning (674 Nm), avbröts testet på grund av mekaniska missljud. Efterföljande inspektion visade på metall-mot-metall-kontakt och synligt kugghjulsslitage, vilket tyder på att smörjfilmen bröts ned vid hög belastning. Bidragande orsaker inkluderade smörjmedlets lägre tryck-viskositetskoefficient (under 5 GPa⁻¹ jämfört med cirka 20 GPa⁻¹ för den syntetiska oljan), kvarvarande föroreningar från tidigare oljor samt skumbildning som ledde till luftinblandning och läckage vid tätningar. Arbetet bidrar till en fördjupad förståelse av smörjningsmekanismer i marina transmissioner och belyser de nuvarande begränsningarna för vattenbaserade smörjmedel vid höga belastningar. Samtidigt har ett transparent växellådshölje utvecklats, vilket utgör en praktisk plattform för framtida visualiseringar och experimentell forskning. Förslag på framtida arbete inkluderar förbättrade rengöringsmetoder för ytor, utvärdering av påverkansfaktorer för prestanda hos vattenbaserade smörjmedel vid hög belastning samt rekommendationer för förbättringar och lämplighet i lågbelastade marina drivlinor som ett steg mot mer hållbara lösningar
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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