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North Carolina State University

1. Ingle, Nilesh Pandharinath. Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures.

Degree: MS, Textile Technology Management, 2004, North Carolina State University

In the current investigation the mechanical performance of barbed sutures made from resorbable and non-resorbable polymer monofilaments were studied. The main objective was to find a method to differentiate between those polymers that form "good" barbs and those that do not. To achieve this objective a suture/tissue pull-out test was developed in which the suture was stressed in a tensile test until it was removed from a tissue simulant specimen. This test was conducted on four resorbable sutures: Biosyn, Maxon, Monocryl & PDS and on three non-resorbable sutures: Ethilon, Novafil & Prolene. Those barbed sutures giving a pull-out load in excess of 1.5 kg were considered to have "good" barbs with adequate mechanical performance. X-ray diffraction, differential scanning calorimetry and tensile testing experiments were performed on the suture polymers in an attempt to identify which microstructural characteristics of the polymer and/or mechanical properties of the monofilament are associated with "good" barb performance. It was found that Maxon, PDS, Ethilon and Prolene sutures gave superior barb performance. Small compactly arranged crystalline structures were found to be the most important factor for the formation of "good" barbs. In addition, the peak tensile elongation of the unbarbed suture was also found to correlate with superior barb performance. The peak tensile force, modulus and toughness of the monofilament appeared to have no effect. It is therefore concluded that the ability of a polymer to form good barbs depends on small crystal size and high tensile elongation. Barb failure was observed to proceed through one of two mechanism; either curling or peeling. Two dimensional finite element analysis of the barb geometry identified the stress concentrations in and near the barbs under load, which were in agreement with the mechanisms of barb failure as observed by image analysis. Advisors/Committee Members: Dr. David R. Buchanan, Committee Member (advisor), Dr. Subhash K. Batra, Committee Member (advisor), Dr. Martin W. King, Committee Chair (advisor).

Subjects/Keywords: medical textile; x-ray; image analysis; dsc; suture; barbs

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ingle, N. P. (2004). Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures. (Thesis). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/2628

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ingle, Nilesh Pandharinath. “Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures.” 2004. Thesis, North Carolina State University. Accessed April 26, 2019. http://www.lib.ncsu.edu/resolver/1840.16/2628.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ingle, Nilesh Pandharinath. “Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures.” 2004. Web. 26 Apr 2019.

Vancouver:

Ingle NP. Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures. [Internet] [Thesis]. North Carolina State University; 2004. [cited 2019 Apr 26]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2628.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ingle NP. Mechanical Performance and Finite Element Analysis of Bi-directional Barbed Sutures. [Thesis]. North Carolina State University; 2004. Available from: http://www.lib.ncsu.edu/resolver/1840.16/2628

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Al-Murayati, Haider. Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon.

Degree: Docteur es, Biologie, 2017, Paris Saclay

Les plumes d'oiseaux abritent de nombreux microorganismes qui pourraient être acquis dans l'environnement, ces microorganismes pouvant exercer une sélection intense sur leurs hôtes en réduisant leur fécondité et leur survie. Plusieurs taxons bactériens qui vivent sur des plumes ont la capacité de dégrader la kératine des plumes et causent des dommages à leur structure et peuvent modifier aussi leur coloration. Les oiseaux utilisent des signaux visuels tels que des couleurs vives ou des ornementations exagérées pour la communication socio-sexuelle ainsi que la reconnaissance des espèces. Seuls les individus en bonne santé sont capables de produire des caractères sexuels secondaires exagérés et restent résistants aux parasites débilitants. Le paon (Pavo cristatus) est une espèce polygame qui a plusieurs décorations exagérées, les caractères sexuels secondaires les plus remarquables du paon sont leur traîne décorée avec des ocelles magnifiques qui contiennent trois couleurs irisées différentes. Grâce à une technique basée sur la culture, j'ai isolé la communauté bactérienne des plumes de différentes parties colorées des ocelles de la traîne du paon. L'étude révèle qu'il y a eu une répartition hétérogène des bactéries parmi les différentes parties colorées des ocelles. L'abondance et la prévalence des taxa bactériens spécifiques étaient liées au degré de dégradation des plumes, à l'expression de différents caractères sexuels secondaires, à des changements dans la coloration des ocelles et à l'augmentation de la croissance quotidienne des plumes. En outre, nous avons constaté un petit effet de l'expression de caractères sexuels secondaires sur la proportion sexuelle des couvées avec un biais en faveur des individus masculins. Les travaux présentés dans cette thèse fournissent des preuves que les ocelles de plumes peuvent être considérés comme un signal fiable de la diversité et de l'abondance de bactéries chez le paon. En conséquence, ils représentent une indication pour la qualité individuelle, ce qui permet aux femelles de choisir des mâles avec une communauté bactérienne spécifique.

Bird feathers harbour numerous microorganisms that could be acquired from the surrounding environment, these microorganisms may exert intense selection on their hosts by reducing fecundity and survivorship. Several bacterial taxa that live on feathers have the ability to degrade feather keratin and cause damage to feather structure and may alter the feather colouration. Birds use visual signals such as bright colours or exaggerated ornamentation for socio-sexual communication as well as species recognition. Only healthy individuals are able to produce exaggerated secondary sexual characters and still remain resistant to debilitating parasites. Peacocks (Pavo cristatus) is a polygamous species that have different exaggerated ornamentation, the most notable secondary sexual characters of the peacock are their long-decorated trains that comprise the magnificent ocelli which contain three different iridescent colours. Through a culture based…

Advisors/Committee Members: Møller, Anders Pape (thesis director).

Subjects/Keywords: Pavo cristatus; Diversite bactérienne; Barbules; Barbes; Dégradation des plumes; Incréments de croissance quotidienne; Coloration des plumes; Traîne paon ocelles; Sexe ratio; Caractère sexuel secondaire; Pavo cristatus; Bacterial diversity; Barbules; Barbs; Feather degradation; Daily growth increments; Feather colouration; Peacock train ocelli; Sex ratio; Secondary sexual characters

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Al-Murayati, H. (2017). Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon. (Doctoral Dissertation). Paris Saclay. Retrieved from http://www.theses.fr/2017SACLS096

Chicago Manual of Style (16th Edition):

Al-Murayati, Haider. “Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon.” 2017. Doctoral Dissertation, Paris Saclay. Accessed April 26, 2019. http://www.theses.fr/2017SACLS096.

MLA Handbook (7th Edition):

Al-Murayati, Haider. “Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon.” 2017. Web. 26 Apr 2019.

Vancouver:

Al-Murayati H. Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon. [Internet] [Doctoral dissertation]. Paris Saclay; 2017. [cited 2019 Apr 26]. Available from: http://www.theses.fr/2017SACLS096.

Council of Science Editors:

Al-Murayati H. Diversity of the bacterial community and secondary sexual characters in the peacock : Diversité de la communauté bactérienne et caractères sexuels secondaires chez le paon. [Doctoral Dissertation]. Paris Saclay; 2017. Available from: http://www.theses.fr/2017SACLS096

3. Kashyap, Shalini. A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes .

Degree: 2012, University of Ottawa

This thesis focused on investigating flow, coherent structures, and mechanisms leading to scour around a series of three submerged groynes in a high curvature (radius of curvature (R)/channel width (B)=1.5) channel bend using a Large Eddy Simulation Numerical (LES) model. Flow was investigated during both an initial and a later stage of scour. The results showed that the groynes appeared effective in keeping the main core of high streamwise velocity away from the outer bank wall in the region where they were installed, although high potential still existed for local scour around the groynes. During the initial stage of scour, horseshoe vortices (HVs) showed the greatest propensity to induce scour immediately upstream of the groyne tips. During the later stage of scour, the HV in front of the first upstream groyne (G1) induced very high mean pressure fluctuations on the outer bank wall. Scour was also of very great concern around the tip of G1 due to severe mean bed pressure fluctuations. Downstream of the groyne field, the presence of a counter-rotating outer bank cell was capable of endangering the stability of the outer bank. The second focus of this thesis was to investigate flow in a 135° channel bend using both Reynolds Averaged Navier Stokes (RANS) and LES numerical models. The RANS study examined the effects of curvature ratio (R/B), and aspect ratio (B/H, where H is the inlet flow depth), on secondary circulation strength, and bed shear stresses. The study revealed that a decrease in R/B was associated with an increase in secondary circulation strength and peak bed shear stress. A change in B/H also substantially affected cross stream circulation strength. The LES study was conducted in a 135° (R/B = 1.5) bend flume with a fixed bed corresponding to near equilibrium scour conditions, and the results were compared to a similar high curvature 193° bend numerical study. Inner bank vortices and shear layers were present in both cases although their characteristics were substantially different. Distributions of boundary friction velocities, and turbulence were also quite different for each case.

Subjects/Keywords: river erosion; submerged groynes; stream barbs; bend erosion; Large Eddy Simulation; Reynolds Averaged Navier Stokes Model; coherent structures; numerical modeling; bed hardening technique

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kashyap, S. (2012). A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes . (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/23323

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Kashyap, Shalini. “A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes .” 2012. Thesis, University of Ottawa. Accessed April 26, 2019. http://hdl.handle.net/10393/23323.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Kashyap, Shalini. “A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes .” 2012. Web. 26 Apr 2019.

Vancouver:

Kashyap S. A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes . [Internet] [Thesis]. University of Ottawa; 2012. [cited 2019 Apr 26]. Available from: http://hdl.handle.net/10393/23323.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kashyap S. A 3-D Numerical Study of Flow, Coherent Structures and Mechanisms Leading to Scour in a High Curvature 135° Channel Bend with and Without Submerged Groynes . [Thesis]. University of Ottawa; 2012. Available from: http://hdl.handle.net/10393/23323

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.