Dissertations / Theses: 'Spinning'

1

Dennhardt, Helge. "Spinning p-branes." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964517752.

APA, Harvard, Vancouver, ISO, and other styles

2

Walters, Claire M. "Spinning a War." Thesis, Boston College, 2004. http://hdl.handle.net/2345/487.

Abstract:

Thesis advisor: John J. Michalczyk
This thesis explores public relations tactics employed by the United States government during the second Iraq war. It discusses the similarity between public relations and propaganda, giving an in-depth exploration of the strategies used by the government before, during, and after the war to garner support for the effort
Thesis (BA) — Boston College, 2004
Submitted to: Boston College. College of Arts and Sciences
Discipline: Fine Arts
Discipline: College Honors Program

APA, Harvard, Vancouver, ISO, and other styles

3

Music, Omer. "Flexible asymmetric spinning." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609554.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Wagenaar, Chelsea. "The Spinning Place." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc862843/.

Full text

Abstract:

"The Spinning Place" finds its impetus in the intersection of the spiritual and material, and while often dwelling in a domestic milieu, the poems move outward both figuratively and literally. For instance, one poem re-narrates the tale of Rumpelstiltskin, several poems are about divination by various means (frogs, animal behavior), and another performs an erasure of the last supper so that it instead tells a woman's experience in a delivery room. I borrow the title of the collection from a stanza of Dylan Thomas's poem "Fern Hill," and the excerpt (which will become an epigraph to the book) reads: "So it must have been after the birth of the simple light / In the first, spinning place, the spellbound horses walking warm / Out of the whinnying green stable / On to the fields of praise." Thomas refers to the newly created earth as the "spinning place," imagining the fleeting idyll and harmony of that scene. In a similar way, my new poems specifically explore moments of creation, birth, and discovery, drawing from a variety of inspirations, including recognizable narratives and myths, as well as personal experience.

APA, Harvard, Vancouver, ISO, and other styles

5

Dhadwal, Renu. "Fibre spinning model analysis /." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974857327.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Odero, Christine A. (Christine Adhiambo). "Polymer gel spinning machine." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/34092.

Full text

Abstract:

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.
Includes bibliographical references (leaves 117-118).
by Christine A. Odero.
M.S.

APA, Harvard, Vancouver, ISO, and other styles

7

Shoot, Erin Janel. "Spinning the Plan Sideways." UKnowledge, 2016. https://uknowledge.uky.edu/english_etds/32.

Full text

Abstract:

Spinning the Plan Sideways is the story of Clara Gantz, a thirty-eight year old architect who spent her twenties getting her plans—and sections and elevations—just right. She built buildings in lieu of a family and has considered these buildings her children, but lately she’s been finding a void in wood, marble, and steel. Encouraged, with methods bordering on coercion, by Greta, her “sister” from the Gantz Home for Girls, Clara agrees to mentor Julien, a troubled twelve-year-old. Years ago, when Julien was five, his mother split their house apart, lifting it to make three-stories from one, and moved into the top level with her new husband and daughter, leaving Julien and his father, Michel on the levels below. The separation drove Michel to attempt suicide on Julien’s ninth birthday leaving him with violent aversions to homes over one-story tall. As Clara works with Julien, she discovers her life had been focused on developing the wrong types of plans and she invests in creating new plans for herself, Julien, and Michel. The story unfolds through the parallel viewpoints of Clara and Michel, with Julien’s Grim Fairytale tucked in the middle.

APA, Harvard, Vancouver, ISO, and other styles

8

He, Peng. "Process-structure-property relationships of yarns produced on the card-spinning system." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131148/unrestricted/he%5Fpeng%5F200405%5Fms.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Watts, Jeremy S. "Modeling the fiberglass spinning process." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5197.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2007.
Title from document title page. Document formatted into pages; contains vii, 92 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 73-74).

APA, Harvard, Vancouver, ISO, and other styles

10

Cicek, H. "Computer simulation of melt spinning." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235356.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Conahan, Gillian S. "Bulletproof gossamer : spinning a superfiber." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68474.

Full text

Abstract:

Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 34).
Spider silk is a material of extraordinary beauty and utility. From the spider's perspective, it is foremost a building material, but also a safety net, a sensory organ, a weapon. From a human perspective, it is a material of extraordinary mechanical properties, an object of artistic and cultural interest, and a valuable window into the evolutionary history of spiders. Historically, there have been a mere handful of spider silk textiles, the most recent example of which was constructed by Simon Peers and Nicholas Godley. This was an extravagant work of art, and the silk was collected entirely by hand. Though the finished article is a testament to the beauty of spider silk, it also illustrates the technical challenges associated with obtaining it in any significant quantity. The effects of this scarcity are evident in the lab of David Kaplan at Tufts University. His group has developed a wide variety of applications for silk, but has focused mainly on silkworm silk in spite of spider silk's greater variety and superior mechanical properties. In the wild, spiders use silk for everything from weaving webs and capturing prey to breathing underwater. Shaped by almost every environment on Earth, spider silk has evolved into endless variations and permutations, offering a vast wealth of material knowledge if we can find a way to tap it. A visit to Cheryl Hayashi's spider silk genetics lab at the University of California, Riverside offers a look inside a spider and a glimpse of how genetic research can illuminate the evolution of silk. At the same time, it puts the limits of our knowledge into stark relief. The scarcity of natural spider silk has helped to drive a small industry in bioengineered and synthetic silk research, and also motivated projects that seek to apply the structural principles of silk fibers to other materials. But so far, these efforts are only a pale imitation of the real thing. For now, the spider is keeping her secrets.
by Gillian S. Conahan.
S.M.in Science Writing

APA, Harvard, Vancouver, ISO, and other styles

12

Davies, Gwilym. "Natural and bioinspired silk spinning." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:e7ec14e5-efff-4e19-b1a0-4c9f02ade678.

Full text

Abstract:

This thesis describes an investigation into silk spinning, with the objective of producing high performance silk fibres in the laboratory using a novel spinning device based upon observations on natural spinning glands and processes. After an in-depth literature review the work is reported in two sections: natural and artificial spinning. The literature provides fragmented data on different aspects of natural silk production, and artificial spinning has not yet reproduced fibres with the properties of native silk fibres, despite unfounded claims of biomimetic spinning. The first half of the thesis looks at natural silk spinning. The work started with a general study of the morphology of spider and silkworm spinning ducts: First, how the silk fibre develops as the dope flows through the gland; and second the relationship between silk fibre properties and both gland morphology and spinning speed. More detailed studies using histochemical and spectroscopic investigations showed that the silk ducts of the spider Nephila edulis and the silkworm Bombyx mori both contain β-chitin, despite an evolutionarily distant common ancestor. Finally, observations showed that the duct of N. edulis consists of alternating nanoporous discs, and FEA modelling indicated that the duct is optimised for mechanical integrity and permeability. The second half of the thesis describes the development of a spinning device that uses natural silk dope mainly taken from B. mori as feedstock. It begins with a description of the gradual development of the engineering aspects of the spinning device, to meet challenges raised during the spinning investigation. The development of a centrifugal capillary rheometer, for practical quantitative insights into rheological processes is then presented. Finally the spinning investigation is reported: first, the screening of spinning in glass capillaries based upon natural gland dimensions and flow rates, which have been shown to induce fibrillation in silk dope in a rheometer, and also included initiation of instability through heat applied along the capillary; second, the final spinning evaluation, using lessons learned from all the screening trials throughout the project, but also including a key development of a hydrophobic coating on the capillary tip to inhibit droplet formation and massively increase the process stability and ease of fibre production. The main conclusions from this work are that good silk fibre cannot be spun by flow shear stress alone; and, that heat instability induces indiscriminate gelation of the silk, whose disordered molecular structure gives poor silk fibre properties. The body of work behind these conclusions provides fundamental background information and new insights that will contribute to the next stages of development of artificial silk spinning, from obtaining a better understanding of the biology of natural spinning glands to the engineering difficulties of implementing the bioinspired principles.

APA, Harvard, Vancouver, ISO, and other styles

13

Miner, Lauren A. "Surrender to the Spinning: poems." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3813.

Full text

Abstract:

This collection of poems explores themes of time and space, energy, entropy and decay, and the frames we use to resist the inevitable trend toward disorder that defines a human experience of the observable universe.

APA, Harvard, Vancouver, ISO, and other styles

14

Agarwal, Uday S. "Orientation and crystallization in melt-spinning of poly(ethylene terephthalate) based compositions." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/9975.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Eriksson, Johanna. "Pilot spinning of viscose staple fibres : Screening for imoprtant spinning parameters using design of experiments." Thesis, Umeå universitet, Kemiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-105912.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Tiedemann, Erica J. "Characterization of prehistoric spinning technology : toward the determination of spinning practices employed in Mississippian textiles /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1302186014.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Dodd, Erin Linnea. "U.S. Trends in Short Staple Spinning." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20001116-124455.

Full text

Abstract:

The purpose of this research has been to examine possible factors which effect yarn production and prices in the U.S.The research approach first involved gathering the data from different sources about yarn production and prices. Second, data was gathered about the different factors which could have an effect on these. These factors included enduse demand, cotton consumption, the effect of spinning systems, labor cost and demand, machinery hours and shipments, and the level of imports and exports. Third, the data was compared and conclusions were made based solely on the obvious trends in the data. Fourth, current situations in the textile market were examined in order to conclude if any have had an effect on yarn production and price. The main issues which are facing the textile industry and were included in this analysis were NAFTA, CBI, Asia and the WTO. The effect that these have had and will have on the spinning industry was examined in detail. Fifth, a statistical analysis was conducted. The analysis included the use of a correlation matrix for both yarn production levels and yarn prices in order to see which factors statistically had the strongest impact on these. Overall, this research offers a view into the inside of the U.S. spinning industry, including the dynamics which effect final yarn production levels and yarn prices, as well as situations which will have an impact on the future of the spinning industry.

APA, Harvard, Vancouver, ISO, and other styles

18

Su, Yang. "Theoretical studies of hollow fiber spinning /." Connect to Online Resource-OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1180971638.

Full text

Abstract:

Dissertation (Ph.D.)--University of Toledo, 2007.
Typescript. "Submitted as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Engineering." Bibliography: leaves 200-218.

APA, Harvard, Vancouver, ISO, and other styles

19

Terrill, E. L. "Mathematical modelling of some spinning processes." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

SU, YANG. "Theoretical studies of Hollow Fiber Spinning." University of Toledo / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1180971638.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Wang, Anli. "Spinning Methods for Carbon Nanotube Fibers." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396453563.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Li, David. "Biomimetic modifications to microfluidic silk spinning." Thesis, Boston University, 2014. https://hdl.handle.net/2144/21205.

Full text

Abstract:

Thesis (M.Sc.Eng.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Silk fibers from arthropods possess several favorable properties for biomedical applications, including high mechanical strength and biocompatibility. However, the majority of silk fiber production is currently limited to manipulation of cocoons from the Bombyxmori silkworm. The efficiency of the process can be increased by dissolving waste silk threads and using artificial spinning techniques to spin the proteins back into usable fibers. Once an artificial spinning technique has been perfected, it may be possible to use similar designs to spin recombinant silk proteins into threads with more favorable mechanical properties. The first step towards customizable silk is to artificially spin silk protein into fibers with comparable properties to naturally-derived silk threads. Current microfluidic devices are limited to spinning B. mori silk into weak, poorly-formed fibers. The incorporation of silk gland-like ion gradients and high shear stress into current and novel microfluidic devices is theorized to improve mechanical properties of resultant spun silk. To this end, ion gradients were added to the current microfluidic device. In addition, a novel microfluidic device was developed to increase shear stress. After investigating the individual effects of ion gradients and shear stress on the silk spinning process, an integrated microfluidic device was designed to investigate the combined effects. Computational models of the flow within each microfluidic device were generated and used to predict biomimetic design parameters. Measurements of fiber diameter and pH within the microfluidic devices were collected to verify the accuracy of the computational models. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and mechanical testing measurements were collected to characterize and compare resultant fibers. From these results, relationships were found between the incorporation of ion gradients and shear stress into the spinning process and the properties of the fibers produced.
2031-01-01

APA, Harvard, Vancouver, ISO, and other styles

23

Golzar, Mohammad. "Melt Spinning of the Fine PEEK Filaments." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2004. http://nbn-resolving.de/urn:nbn:de:swb:14-1101380771578-37580.

Full text

Abstract:

The production of fine filaments using the melt spinning process needs considerable effort. A thermoplastic melt is stretched from the spinneret under a constant take-up speed. The high performance thermoplastic PEEK is solidified in the melt spinning process in a small distance and short time. Therefore, the fine PEEK filaments in the fibre formation zone underwent a high deformation and cooling rate. To make the melt spinning process stable and to produce the fine PEEK filaments, material properties and material behaviour are examined using on-line and off-line measurements. The fibre speed measured using Laser Doppler Anemometry and simultaneous temperature measured using infrared thermography enable both the strain rate and consequently the apparent extensional viscosity to be estimated. This provides the apparent extensional viscosity over the spinning line, which can itself show the structural development of PEEK fibres in the fibre formation zone, i.e. necking and solidification phenomena. The one-dimensional fibre formation model must include both procedural and material parameters. The heat transfer coefficient was estimated using the filament temperature measurement and showed a relatively high contribution of radiation and free convection in comparison to forced convection near the spinneret. The improved model of PEEK fibre formation gave a good agreement to both temperature and speed measurements, and also confirmed the high deformation rate effect on the extensional viscosity, which could be simulated with a properly generalised Newtonian constitutive equation. The end properties of the fibres, such as as-spun filament fineness, orientation (expressed using total birefringence) and total crystallisation (examined using DSC) are investigated in relation to different spinning conditions, i.e. take-up speed, throughput and the draw down ratio. The tensile test diagram results, measuring phenomena such as the elongation at break, tenacity, and the Young modulus of elasticity are also analysed in order to complete the correlation of the above-mentioned spinning conditions to the structural properties of as-spun fine PEEK filaments. The melt spinning of fine PEEK fibres under different spinning conditions is examined with the purpose of finding the optimum take-up speed and throughputs. Other spinning conditions, such as the temperature of melt processing, and the arrangement and diameter of the spinneret holes, are changed in order to make the process more stable. The recommendations for further study can be used to further examine some aspects of this work; however, this work presents a new concept for fine PEEK melt spinning supported by spinnability examinations under different spinning conditions and the improved model of fibre formation, which is also relevant for typical industrial processing applications.

APA, Harvard, Vancouver, ISO, and other styles

24

Lundin, Rikard. "Känslotillstånd vid träningsformen spinning jämfört med ensamträning." Thesis, Stockholms universitet, Psykologiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-54616.

Full text

Abstract:

Att fördelarna med fysisk aktivitet är många är välkänt, ändå är uppemot 40% av befolkningen i Sverige fysiskt inaktiva. Vissa träningsformer är bättre och mer lockande än andra. Att träna i grupp antas skilja sig känslomässigt från att träna ensam. Syftet med studien var att undersöka nivåer och skillnader i ansträngnings och emotionsskattningar vid gruppträning jämfört med ensamträning. Sexton personer deltog med spinning som gruppträningsform och cykling på ett laboratorium som ensamträning i en inomindividsdesign där de samtidigt skattat ansträngning och sex känslotillstånd på Borg CR100 skalan. Resultatet visade att bara ett av sex känslotillstånd var signifikant högre efter spinning än laboratoriecykling. Skattningarna på skalan var mycket höga i absoluta tal, könsskillnaderna var små och spinningvana som bakgrundsfaktor tycks vara betydande. Resultaten var oväntade, även då fler känslotillstånd var nära att uppvisa signifikanta skillnader och att inte fler skillnader blev signifikanta förklaras genom metodbrister och för få deltagare i studien.

APA, Harvard, Vancouver, ISO, and other styles

25

Allen, Keith John. "Friction spinning : an investigation of yarn formation." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/27571.

Full text

Abstract:

Friction spinning is a relative newcomer to textile technology. It has generated great interest because of its potential for wide application of certain problems regarding the quality of yarn produced at high output rates can be solved. General acceptance of the process is hindered by uncertainty as to its capability of producing yarns of sufficient strength at speeds greater than 300 m/min. (NB: as a guide, maximum output rates of competitive technologies are no more than 150 m/min.) Friction spinning appears to have no intrinsic self-limit to its maximum output rate, unlike ring and rotor spinning which are limited by centrifugal effects leading to excessive yarn breakages. The process will therefore provide something of a quantum leap in output if acceptable yarn quality is achieved.

APA, Harvard, Vancouver, ISO, and other styles

26

Park, Jung Won. "Fast spinning-top dynamics of photorefractive grating /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1140193991&sid=24&Fmt=2&clientId=1509&RQT=309&VName=PQD.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Doki-Thonon, Thomas. "Thermal effects in elastohydrodynamic spinning circular contacts." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00749882.

Full text

Abstract:

This thesis is devoted to the study of spinning contacts located in bearing between the roller-end and the ring flange. The main direction of the lubricant flow may change when the contact is subjected to skew. This complex kinematics influences the contact behaviour. A dual experimental-numerical approach is proposed to study this problem. The Tribogyr test-rig allows the experimentation of the contact at the 1:1 scale. A film thickness measurement method, based on white light interferometry, was developed on Tribogyr. This method allows the measurement of film thickness between 0 and 800 nm with an accuracy of a few nanometres. The measurement of forces in the main flow direction shows similarities with classical rolling-sliding contacts. However, the friction coefficient is globally lower as soon as spin is involved. Transverse forces are of the same order of magnitude as the longitudinal forces. This is due to transverse shearing caused by the spin. A numerical model has been developed for the simulation of these spinning contacts. The finite element model, which is based on a fully-coupled solving strategy, takes into account the temperature calculation and the lubricant non-Newtonian rheology. Its validation with Tribogyr experimental results in terms of film thickness and friction has been conducted. Spin and skew effects induce high shear-thinning and thermal-thinning of the lubricant that lead to a decrease of the film thickness. Under high spinning condition, the lubricant exiting the contact may be re-injected to the contact inlet. Consequently, the heat transfers between the lubricant and the solids in contact are modified. In contact subjected to high skew, a local increase (dimple) of the film thickness may occur. Important skew may also lead to starvation conditions. Many experimental campaigns, coupled with an intensive use of the numerical model, allowed to understand the physical phenomena involved as well as to predict the efficiency, in terms of power losses, of the spinning contacts.

APA, Harvard, Vancouver, ISO, and other styles

28

Mokabi, G. N. "Opening roller power consumption in rotor spinning." Thesis, University of Bradford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371482.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Hashim, Amir Hisham. "Optimal spinning reserve allocation incorporating risk assessment." Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401334.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

REI, ANDREA DE MATTOS. "METHODOLOGIES FOR POWER SYSTEMS SPINNING RESERVE EVALUATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1992. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14191@1.

Full text

Abstract:

COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Este trabalho trata das metodologias disponíveis mais utilizadas para a avaliação da reserva girante em sistemas de potência. São apresentadas abordagens determinísticas e probabilísticas. Uma grande variedade de aspectos são considerados e organizados de modo a se obter uma taxionomia metodológica. A aplicação da taxionomia sugerida é ilustrada com a análise de um sistema hipotético, o IEEE Reliability Test System, e do sistema brasileiro das regiões Sul/Sudeste/Centro-Oeste. Com base nos resultados obtidos com a aplicação de tal taxionomia à metodologia atualmente utilizada no Brasil, são apontados aspectos que necessitam de maiores pesquisas. Uma das principais conclusões obtidas revela que a prática atual de se associar os períodos críticos de risco àqueles de maior capacidade em manutenção não possui respaldo prático nem teórico.
This report reviews the most representative techniques currency available for power systems spinning reserve evaluation. Both deterministic and probabilistic approaches are tackled. A broad range of aspects are considered and organized in a practical methodological taxonomy. The application of the suggested taxonomy is illustrated with the aid of hypothetical systems, the IEEE Reliability Test System, and the Brazilian South/Southeast/Midwest System. Based on the diagnosis resulting from the application of the taxonomy to the methodology currently utilized in Brazil, several aspects in need of improvement are pointed out. As one of the main results attained, it shown that, the current practice of considering the critical risk period as coincident with the critical maintenance period, lacks practical evidence and theoretical support.

APA, Harvard, Vancouver, ISO, and other styles

31

Zhang, Siqi. "Functional polymer fibre spinning by infusion gyration." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10052048/.

Full text

Abstract:

Fibres show promising applications such as textiles, filtration, sensing and tissue engineering. In this study, an infusion gyration system to produce polymer micro and nano fibres with functions was introduced. By using this method, functional fibres can be formed from polymer solutions mixed with other functional materials. PEO or PVA water solution was used for making the spinning solutions. The fluorescence protein bound with gold nanoparticles was carried by the PEO water solution, from which the fibres assembled with protein were successfully generated through infusion gyration. A mixed molecular weight PVA combined water solution mixed with processed magnetic nanoparticles achieved fabrication of magnetically controllable fibres have the potential for drug release and its demonstration test showed a positive result. This spinning system provides control of the polymer solution flow rate during spinning which affects the fibre morphology such as average diameter and size distribution. The relationship between the spinning parameters and the product properties was studied for better understanding of the method. The analysis of infusion gyration and its fibre forming process was carried out. The fibres were characterised using several methods, such as optical microscopy, SEM, FTIR and UV-Vis, to establish the potential of infusion gyration and to confirm the functions of final fibre product. The infusion gyration system provides a simple micro and nano scale assembly approach to integrate different protein functionalities into nanofibres with potential applications. Magnetic PVA nanofibres are promising for drug delivery.

APA, Harvard, Vancouver, ISO, and other styles

32

Bertarello, Andrea. "Magic-angle Spinning NMR of paramagnetic metalloproteins." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN004/document.

Full text

Abstract:

À ce jour, nos connaissances sur les propriétés structurales et fonctionnelles des métalloprotéines sont essentiellement basées sur des structures résolues par des méthodes de diffraction à rayons X appliquées à des échantillons monocristallins. Cependant, certaines protéines ne cristallisent pas ou cristallisent sous une forme qui n’est pas manipulable ou compatible avec des techniques des diffraction, et même si une structure à très haute résolution est disponible, la nature de l’ion métallique, sa géométrie de coordination ou son état d’oxydation restent souvent indéterminés.La Résonance Magnétique Nucléaire en rotation à l’angle magique (MAS NMR) est une technique très performante pour l’étude de systèmes biologiques et pour la caractérisation de la structure du site actif des métalloprotéines paramagnétiques, mais son application à l’analyse des noyaux proches d’un site paramagnétique est limitée à cause de la résolution et de la sensibilité faibles.L’objectif de cette thèse a été de développer des méthodes RMN basées sur des hautes fréquences de rotation (60-111 kHz MAS) pour faire face à ces problématiques. Un répertoire de séquences d’impulsion pour la détection et l’attribution des noyaux à proximité d’un centre paramagnétique est proposé, et à l’aide de méthodes de calculs de pointes, les données expérimentales acquises sont converties en contraintes structurales afin de déterminer la géométrie du site actif à l’échelle atomique. Cette approche est validée avec l’analyse de sites actifs de deux protéines microcristallines contenants différents ions paramagnétiques : Fe, Cu et Co. Ensuite, des données préliminaires sur un transporteur membranaire d’ions métalliques divalents non cristalline sont présentées.Les méthodes analytiques présentées ici constituent un ensemble d’outils indispensable pour l’élucidation de la structure et la fonction des sites métalliques de systèmes macromoléculaires biologiques
Most of our understanding of metalloproteins derives from atomic or molecular structures obtained from diffraction methods on single crystal samples. However, not all proteins are amenable for diffraction studies, and even when a highly-resolved structure is available, often the nature of the metal ion, its coordination geometry or its oxidation state are not determined. The aim of the present thesis is the investigation of structural properties of metal sites in paramagnetic metalloproteins by Magic-Angle Spinning Nuclear Magnetic Resonance (MAS NMR). MAS NMR is a powerful technique for the investigation of biological systems, and may represent a direct probe of the structure at the active site of paramagnetic metalloproteins. However, it suffers from limited sensitivity and resolution when applied to nuclei close to a paramagnetic center.In this thesis, we address these limitations by developing NMR methods based on ultra-fast (60-111 kHz) MAS rates. A “toolkit” of suitably designed pulse sequences is built for the detection and the assignment of nuclei in close proximity of a paramagnetic center. State-of-the-art computational techniques are also employed to convert the experimental data into structural restraints for obtaining atomic-resolution geometries of active sites. We benchmark this approach with the study of Fe, Cu and Co sites in two microcrystalline proteins, and we also provide preliminary data on a non-diffracting divalent metal ion transporter in lipid membranes. We anticipate that the techniques described here are an essential tool to elucidate many currently unanswered questions about structure and function of metal sites in structural biology

APA, Harvard, Vancouver, ISO, and other styles

33

Boulahbal, Djamil. "Self-excited vibrations of a spinning disk." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11481.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Haseidl, Franz [Verfasser]. "Weiterentwicklung der Spinning-Disc-Technologie / Franz Haseidl." München : Verlag Dr. Hut, 2016. http://d-nb.info/1100969012/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Hsia, Yang. "Biomimicry of the spider silk spinning apparatus." Scholarly Commons, 2011. https://scholarlycommons.pacific.edu/uop_etds/797.

Full text

Abstract:

Spider silk is known for its extraordinary material properties, being both very strong and extensible. Even though the fibers outperform many synthetic and natural materials, it is impractical to collect industrial amounts of silk from spiders due to their cannibalistic and venomous nature; they cannot be farmed like the commercial silk worm Bombyx mori. Thus, scientists have turned to molecular and engineering techniques to replicate the spider's silk and spinning apparatus. In the current literature there is no detailed protocol on the production of consistent synthetic fibers. To accomplish this, the fibroins and natural spinning apparatus were taken apart and analyzed in order to develop a protocol that biomimics the spider's system. The laboratory procedure, using the natural process as an example, was simplified to: protein production, purification, concentration, fiber spinning, and lastly post spin draw. Large quantities of truncated MaSp I spidroin (spider fibroin) was purified from E. coli and successfully spun into fibers using customized spinning, spooling, and stretching apparatuses. The final fiber products displayed mechanical properties that were comparable to other reported synthetic fibers, but more importantly also displayed low experimental variability between samples. The protocol developed in this study can be further used to characterize other spidroins and silk proteins, and can be further advanced to produce even better fibers with enhanced properties.

APA, Harvard, Vancouver, ISO, and other styles

36

Abrahams, Leon Gary. "Computerised speed monitoring system for nylon spinning." Thesis, Peninsula Technikon, 1996. http://hdl.handle.net/20.500.11838/1123.

Full text

Abstract:

Thesis (MTech (Electrical Engineering))--Peninsula Technikon, Cape Town,1996
The Southern Nylon Spinning plant, at South African Nylon Spinners in Bellville - Cape Town - South Africa, is one of the oldest on the site and a need arose to upgrade the existing method used in speed monitoring in this particular plant. This system was unable to produce alarms on speed limits being exceeded (i.e. on under-speed or over-speed). There was no alarm logging or historical trending. Manual records on speed were either incomplete or non-existent. Thus the purpose of this study was to investigate the existing speed monitoring system and implement a suitable computerised method of speed monitoring.

APA, Harvard, Vancouver, ISO, and other styles

37

Sykes, Stephen James. "Operating characteristics of the spinning cone column." Phd thesis, Department of Chemical Engineering, 1995. http://hdl.handle.net/2123/6434.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Jia, Jun. "Melt spinning of continuous filaments by cold air attenuation." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37276.

Full text

Abstract:

Traditionally ultrafine fibers below 1 dpf are produced by extrusion followed by mechanical drawing. A modified melt spinning apparatus with high-speed air nozzle was designed and fabricated to produce continuous polypropylene filaments by cold air drawing only. With this setup, the fiber is quenched and simultaneously attenuated by a symmetric cold air jet. Since the formation of fiber structure is highly dependent on the processing conditions, the new process will provide a unique operation window to study fiber attenuation and structural formation under high-speed cold air drawing. Based on computational fluid dynamics simulation results, a parametric study was carried out under different process conditions which include processing temperature, air velocity and polymer volume flow rate. Effects of changes in processing variables on the fiber diameter, molecular orientation, crystallinity, tensile strength and other properties were studied. Furthermore, a theoretical model was developed to analyze the non-isothermal fiber attenuation mechanisms. The new knowledge obtained in this study would likely yield a new process for producing innovative fiber products.

APA, Harvard, Vancouver, ISO, and other styles

39

Gagov, Atanas. "INSTABILITIES IN ELONGATION FLOWS OF POLYMERS AT HIGH DEBORAH NUMBERS." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1191895515.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Rajamanickam, Rangaswamy. "Studies on fiber-process-structure-property relationships in air-jet spinning." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8661.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Grove, Dale A. III. "Rheology and evolution of order in melt spinning." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/11112.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Gärdsback, Mattias. "Deployment Control of Spinning Space Webs and Membranes." Doctoral thesis, KTH, Strukturmekanik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9574.

Full text

Abstract:

Future solar sail and solar power satellite missions require deployment of large and lightweight flexible structures in space. One option is to spin the assembly and use the centrifugal force for deployment, stiffening and stabilization. Some of the main advantages with spin deployment are that the significant forces are in the plane of rotation, a relatively simple control can be used and the tension in the membrane or web can be adjusted by the spin rate to meet the mission requirements. However, a successful deployment requires careful development of new control schemes. The deployment rate can be controlled by a torque, applied either to a satellite in the center or by thrusters in the corners, or by deployment rate control, obtained by tether, spool braking or folding properties. Analytical models with only three degrees of freedom were here used to model the deployment of webs and membranes for various folding patterns and control schemes, with focus on space webs folded in star-like arms coiled around a center hub. The model was used to investigate control requirements and folding patterns and to obtain optimal control laws for centrifugal deployment. New control laws were derived from the optimal control results and previously presented control strategies. Analytical and finite element simulations indicate that the here developed control laws yield less oscillations, and most likely more robustness, than existing controls. Rotation-free (RF) shell elements can be used to model inflation or centrifugal deployment of flexible memebrane structures by the finite element method. RF elements approximate the rotational degrees of freedom from the out-of-plane displacements of a patch of elements, and thus avoid common singularity problems for very thin shells. The performance of RF shell elements on unstructured grids is investigated in the last article of this thesis, and it is shown that a combination of existing RF elements performs well even for unstructured grids.
QC 20100729

APA, Harvard, Vancouver, ISO, and other styles

43

Fredbo, Maren. "The Heterogeneous Multiscale Method and the Spinning Top." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13727.

Full text

Abstract:

The heterogeneous multiscale method (HMM) was proposed by E and Engquist and is considered to be an efficient method for problems with multiple time scales. We give a short introduction to the HMM for multiscale problems in general, before we restrict our work to HMM schemes developed for stiff ODEs, based on results found by Engquist et al. HMM provides an efficient and systematic way to move between the macroscopic and microscopic model in a problem having multiscale physics. By taking advantage of scale separation in multiscale problems, the HMM approximates the macroscopic variables of the solution without fully resolving the microscopic solution. This introduces computational savings as the total number of evaluations needed for convergence are significantly reduced.We test the features of the HMM on the spinning top. The governing equations of the top produces a highly oscillatory solution as the top spins fast. Despite this fast oscillating nature, we would intuitively expect some slow behavior of the top, for instance the inclination from the vertical axis or the circulation of the top around the vertical axis. We find a set of slow variables of the spinning top, and show that the HMM provides an accurate solution of the macroscopic variables of the top, with a significant gain in computational cost compared to standard solvers.We also study the spinning top subjected to a vibrational external force and find a set of slow variables, which can be approximated accurately with HMM. Finally, we find an averaged equation to the spinning top subjected to a vertical vibrating force. This analysis is based on the Modulated Fourier expansion.The work of this thesis is an extension of my semester project, and we emphasize that the theory part of this thesis is partially from this work.

APA, Harvard, Vancouver, ISO, and other styles

44

Polyblank, James Alexander. "The mechanics and control of flexible asymmetric spinning." Thesis, University of Cambridge, 2015. https://www.repository.cam.ac.uk/handle/1810/256513.

Full text

Abstract:

Metal spinning is a sheet forming process to produce axisymmetric products, but its commercial operation still depends on a dedicated mandrel which determines the shape of the product, and skilled craftsmen to control the working tool. In Flexible Asymmetric Spinning (FAS) the mandrel is replaced with three numerically controlled internal rollers, thereby removing the setup time and cost associated with producing the dedicated mandrel. However, if FAS could also be automated, the setup time and cost could be reduced further. This thesis focuses on three elements which need to be in place for the automation of FAS: the automation of the internal rollers; compensation for springback; and toolpath design to prevent failure. Typically, automation requires a process model. To automate the internal rollers, a process model which predicts the effect of the internal roller position on the workpiece shape would be required – but as FAS is a novel process, no such models exist. To compensate for springback, a model of workpiece shape is required. To prevent failure, a model of the two modes of failure – wrinkling and tearing – is needed. For offline automation, these should be accurate models – but accurate models of both workpiece shape and failure are too slow to make this feasible. For online automation, fast, approximate models can be used – measurements of the product can be fed back in order to compensate for the model errors. However, a literature review showed that no models exist for workpiece shape or failure which are both fast enough for online use, and detailed enough to give information on how tool actions should be changed. This is why FAS has not yet been automated. In previous work, the internal rollers were positioned through trial-and-error and only a straightwalled cup was successfully produced. In this work, a laser line scanner is installed to measure the workpiece shape online, and one of the internal rollers is positioned at the point where the workpiece just begins to diverge from the target shape. This prevents overlap with the target shape, and allows a greater range of products to be made. Springback is typically prevented in conventional spinning by pressing the material hard against the mandrel. This is not possible in FAS due to the force limits on the internal tools. However, in FAS it is possible to move the working roller inside the target shape to compensate for springback. The laser line scanner is used to measure springback and calibrate a simple elastic cantilever model of springback online. By using this model to calculate how far to move the tool inside the target shape, springback errors are reduced by 75%. Two approaches to toolpath design to avoid failure are investigated: Firstly, a finite horizon control system – where failure is checked for only for a short time into the future – is tentatively demonstrated using a slow but accurate finite element (FE) model, but this is too slow for industrial use. However, with a faster, linear-elastic model, the control system is too conservative and fails to produce the final product. Secondly, an empirical approach is investigated: a series of trials are carried out with a parameterised toolpath. The result is a tentative set of rules for toolpath design which may provide the basis for a future control system. Overall, this thesis makes steps towards the automation of internal rollers, compensation of springback, and design of toolpaths to prevent failure in FAS. With further work to extend the control system developed here to automate all three internal rollers and to verify the robustness of the springback compensation system, any conventional spinning machine could potentially be replaced by an FAS machine – with the toolpath of the working roller designed manually, as it currently is in conventional spinning. Yet the tentative sets of rules on toolpath design also open the door to a potential automatic toolpath generation system, and further work should begin by testing the robustness of these rules with changes in material and geometry. Then, with some likely extensions, they could be embedded into a working control system to fully automate FAS.

APA, Harvard, Vancouver, ISO, and other styles

45

Min, Byung No. "Non-linear free vibration of a spinning tether." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29616.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Pitre, J. D. Gilbert. "Spinning mode algorithms for the Satellite Attitude Sensor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0017/MQ48456.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Baddour, Natalie. "A modelling and vibration analysis of spinning disks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ59013.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Zhang, Yi. "Solution studies on soybean protein for fiber spinning." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/10287.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Min, Byung No 1967. "Non-linear free vibration of a spinning tether." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27243.

Full text

Abstract:

Non-linear vibration of a spinning tether is studied in this thesis. The tether is thought to be a part of a spinning tethered satellite system in the station-keeping phase so that the tether has a constant nominal length and is forced to spin at a constant rate about its nominal axis. Using the extended Hamilton's principle the governing equations of motion are derived retaining non-linear terms up to the third order that originate from geometric non-linearity. They are discretized by the assumed-modes method, truncated to one-mode equations, and transformed to the phase-space form. Then the method of averaging is applied.
When the tether has high nominal tension, averaging with two variables results in a closed form solution, which shows dependence of the frequency contents on the initial amplitude parameters of the system. In the case of very low nominal tension, averaging with a single variable is useful to obtain the steady state and the limit steady state solutions, both of which result in a circular whirling motion like a skip-rope. Without damping, a general transverse mode appears to be quasi-periodic but it can be periodic under certain initial conditions. Numerical investigations reveal that the material damping through the longitudinal mode derives the steady state to the limit steady state. Also, several interesting shapes are observed in phase plots.

APA, Harvard, Vancouver, ISO, and other styles

50

Glaubitz, Clemens. "Magic angle sample spinning NMR spectroscopy on biomembranes." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267922.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Spinning'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles