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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

A report on the surfactant system of the lung

Ray, Jeanette Susan January 2010 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
292

Identification of constitutively active forms of Arabidopsis MAP Kinases : brings more evidence on MPK4 function in plant immunity / Identification de mutants constitutivement actifs de MAP Kinases d’Arabidopsis : démonstration de leur intérêt à travers l’étude de la fonction de MPK4 dans les réponses aux pathogènes

Berriri, Souha 10 January 2012 (has links)
La phosphorylation/déphosphorylation des protéines est un mécanisme de signalisation intracellulaire commun. Parmi les kinases végétales, les Mitogen-Activated Protein Kinases (MAPKs) sont impliquées dans de nombreux processus biologiques importants, comme la réponse aux stress biotiques et abiotiques, le développement et la dynamique du cytosquelette. Chez Arabidopsis thaliana et ce malgré de nombreux efforts, les fonctions des kinases impliquées dans les cascades MAPK restent peu inconnues. L'activation des kinases en utilisant des mutations mimant la phosphorylation des sites normalement phosphorylés est une approchequi a fait ses preuves dans le cas de MAP2Ks et a largement contribué à élucider leurs fonctions. Cette stratégie s’est révélée impossible dans le cas des MAPKs, puisque les résidus à muter restent encore à identifier. Pour contourner ce problème, nous avons adapté un crible basé sur la complémentation fonctionnelle d’un mutant MAPK de levure avec des formes aléatoirement mutées de MPK6d’Arabidopsis dans le but d'identifier des mutants présentant une activité constitutive. Nous en avons identifiés plusieurs et avons montré que ces formes constitutivement actives (CA) de MPK6 sont actives sans phosphorylation par les MAP2Ks. Par ailleurs, les mutations des résidus équivalents dans d'autres MAPKs les rendent également hyperactives, ce qui indique que cette stratégie peut être utilisée comme approche générale pour activer les MAPKs afin d’en comprendre les fonctions. L’étude des interactions protéine-protéine et l’analyse des profils dephosphorylation indiquent que les MAPKs CA conservent leur spécificité envers leurs substrats et interacteurs. Comme preuve de concept, nous avons généré des formes actives du MPK4. La MPK4 CA exprimée sous son propre promoteur a parfaitement complémenté le mutant mpk4. La caractérisation des lignées exprimant MPK4 CA confirme le rôle négatif de cette kinase dans les réponses de défense aux pathogènes des plantes que ce soit dans la PTI (PAMP Triggered Immunity) ou dans la ETI (Effector Triggered Immunity). Globalement, ce travail permettra de fournir des informations directes sur les cibles des MAPKs et devrait contribuer à la compréhension globale de la transduction du signal chez les plantes. / Protein phosphorylations and dephosphorylations are common events occurring duringintracellular signaling processes. Among plant kinases, Mitogen-Activated Protein Kinases (MAPKs) are involved in signaling of many important biological processes, including biotic and abiotic stresses, development and cytoskeleton organization. Despite an abundant literature on MAPKs, the exact roles and direct targets of many Arabidopsis thaliana MAPKs are not clear yet. The activation of kinases using phospho-mimicking mutations of the phosphorylated residues was a successful approach in the case of MAP2Ks, helping to elucidate their functions. This strategy failed in the case of MAPKs since the necessary residues to mutate remain unclear. To bypass this problem, we adapted a screen based on the functional complementation of a MAPK yeast mutant with randomly mutated Arabidopsis MPK6 in order to identify the ones mutants showing constitutive activity. We identified several clones and showed that these constitutively active (CA) of MPK6 candidates are indeed active without phosphorylation by MAP2Ks. Interestingly, mutations of the equivalent residues in other MAPKs triggered constitutive activity as well, indicating that this strategy may be used as a general approach to activate MAPKs and identify their functions. Interaction and phosphorylation assays indicatedthat CA MAPKs retain their substrate and interactor specificity. As proof-of-concept, we generated active versions of MPK4. CA MPK4 expressed under itsown promoter successfully complements mpk4 mutant plants. Characterization of CA MPK4 lines further confirmed the negative role of MPK4 in plant pathogen defense responses and its implication in both PTI (PAMP Triggered Immunity) and ETI (Effector Triggered Immunity). Overall, the work will help to provide direct information on all MAPK targets and should be an important contribution to the overall understanding of signal transduction in plants.
293

Audio band integrated active RC filter with digital frequency tuning.

January 2005 (has links)
Yeung Nang Ching. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 72-74). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.I / ABSTRACT --- p.II / 摘要 --- p.III / TABLE OF CONTENTS --- p.IV / LIST OF FIGURES --- p.VII / LIST OF TABLES --- p.X / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Overview of filter --- p.1 / Chapter 1.1.1 --- History --- p.1 / Chapter 1.1.2 --- Application of analog filter --- p.2 / Chapter 1.1.3 --- Category of continuous time filters --- p.3 / Chapter 1.1.4 --- Problem issued from Active RC filter --- p.7 / Chapter 1.2 --- Motivation --- p.7 / Chapter 1.3 --- Outline --- p.8 / Chapter CHAPTER 2 --- FILTER FUNDAMENTAL --- p.9 / Chapter 2.1 --- Overview --- p.9 / Chapter 2.2 --- Terminology --- p.9 / Chapter 2.3 --- General Goals of Filter Design --- p.11 / Chapter 2.4 --- Standard Lowpass Filter Characteristic --- p.11 / Chapter 2.4.1 --- Butterworth --- p.11 / Chapter 2.4.2 --- Chebyshev --- p.12 / Chapter 2.4.3 --- Elliptic-Function --- p.13 / Chapter 2.5 --- Study on Different Tuning Approaches --- p.13 / Chapter CHAPTER 3 --- CURRENT DIVISION NETWORK (CDN) --- p.18 / Chapter 3.1 --- Overview of Current Division Technique --- p.18 / Chapter 3.2 --- Second Order Effects --- p.23 / Chapter 3.3 --- Working Principle of CDN --- p.23 / Chapter 3.4 --- Performances of CDN --- p.25 / Chapter 3.4.1 --- General Properties of CDN --- p.25 / Chapter 3.4.2 --- Input Resistances of CDN --- p.26 / Chapter 3.4.3 --- Noise Performance of CDN --- p.27 / Chapter CHAPTER 4 --- REALIZATION OF THE FILTER --- p.31 / Chapter 4.1 --- Overview --- p.31 / Chapter 4.2 --- Traditional Kerwin Huelsman Newcomb (KHN) Biquad --- p.31 / Chapter 4.2.1 --- State Variable Method --- p.31 / Chapter 4.2.2 --- KHN Biquad --- p.32 / Chapter 4.3 --- Proposed Filter --- p.33 / Chapter 4.3.1 --- Biquad with CDN --- p.33 / Chapter 4.3.2 --- A dvantages of Proposed Filter --- p.36 / Chapter 4.3.3 --- Schematic of Proposed Filter --- p.38 / Chapter CHAPTER 5 --- LAYOUT CONSIDERATION --- p.41 / Chapter 5.1 --- Overview --- p.41 / Chapter 5.2 --- Process Information --- p.41 / Chapter 5.3 --- Transistor Layout Techniques --- p.42 / Chapter 5.3.1 --- Multi-finger Layout Technique --- p.42 / Chapter 5.3.2 --- Common-Centroid Structure --- p.43 / Chapter 5.3.3 --- Guard Ring --- p.45 / Chapter 5.4 --- Passive Element Layout Techniques --- p.45 / Chapter 5.5 --- Layout of Whole Design --- p.47 / Chapter CHAPTER 6 --- SIMULATION RESULT --- p.49 / Chapter 6.1 --- Operational Amplifier --- p.49 / Chapter 6.2 --- Overall Performance of filter --- p.55 / Chapter CHAPTER 7 --- MEASUREMENT RESULT --- p.60 / Chapter 7.1 --- Measurement Setup --- p.60 / Chapter 7.2 --- Time Domain Measurement --- p.62 / Chapter 7.3 --- Frequency Domain Measurement --- p.63 / Chapter 7.4 --- Measurement of Non-Linearity --- p.66 / Chapter 7.5 --- Summary of the Performance --- p.69 / Chapter 7.6 --- Comparison on Tuning Ability --- p.70 / Chapter CHAPTER 8 --- CONCLUSION --- p.71 / BIBLIOGRAPHY --- p.72
294

Fundamental studies and methods development for the determination of cationic surfactants in capillary electrophoresis

So, Shi Kit 01 January 1999 (has links)
No description available.
295

Effects of surfactants and organic amendments on phytoremediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil

Cheng, Ka Yu 01 January 2005 (has links)
No description available.
296

Emergência e desenvolvimento da ação nos apertos manuais de bebês / Emergence and development of the action of clutch behavior in infants

Priscilla Augusta Monteiro Ferronato 15 May 2015 (has links)
Esse estudo tem como tese que o comportamento de recém nascidos e bebês é ativo, ou seja, guiado a uma meta específica e baseado no conhecimento a respeito do ambiente ao seu redor. Também é assumido que essa capacidade de adaptação se fortaleça ao longo dos 4 primeiros meses após o nascimento. Foram investigadas as atividades manuais de recém nascidos e bebês, tendo em vista que as mãos são uma importante ferramenta de percepção e interação com o ambiente. Assim, os objetivos do estudo foram: a) descrever o comportamento de apertar ao longo dos 4 primeiros meses após o nascimento; e b) identificar acoplamentos entre apertos manuais e o contexto ambiental durante os quatro primeiro meses após o nascimento. Os resultados mostraram que os bebês alteraram a organização temporal dos apertos diferentemente nas situações de contingência e não contingência, um indicativo inicial do comportamento ativo nos apertos manuais / This thesis searched for evidences that newborns and infants behaviour are active, in the other words, intentional, guide by a goal and based in environment knowledge. Also, it is suggested that the adaptation capacity improve around the first 4 months of age Thereunto, the manual activities were investigate, because the hand is an important font of perception and interaction with the environment. So, the goals of the study were: a) to describe neonate and infant clutches around four first months after birth; and b) to verify the coupling between clutches and environmental outcomes during the first four months after birth. The results showed that infants could alter the temporal organization of clutches differently in contingent and no contingent conditions, an initial indicative of active clutch behaviour in young infants
297

The role of reactive oxygen species during erythropoiesis: an in vitro model using TF-1 cells.

January 2009 (has links)
Ge, Tianfang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 87-93). / Abstract also in Chinese. / EXAMINATION COMMITTEE LIST --- p.ii / DECLARATION --- p.iii / ACKNOWLEDGEMENTS --- p.iv / ABSTRACT --- p.v / ABSTRACT IN CHINESE --- p.vii / ABBREVIATIONS --- p.ix / TABLE OF CONTENTS --- p.xiii / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Erythropoiesis --- p.2 / Chapter 1.2 --- The TF-1 model --- p.3 / Chapter 1.3 --- The erythroid marker glycophorin A (GPA) --- p.4 / Chapter 1.4 --- Reactive oxygen species (ROS) --- p.4 / Chapter 1.5 --- Oxidative stress in human erythrocytes --- p.6 / Chapter 1.6 --- Antioxidant defense systems --- p.6 / Chapter 1.7 --- Glucose provides the majority of reducing equivalents in human erythrocytes --- p.9 / Chapter 1.8 --- Glucose transporter type 1 (Glut l) transports glucose and vitamin C into human erythrocytes --- p.10 / Chapter 1.9 --- Hypothesis and objectives --- p.11 / Chapter 1.10 --- Long-term significance --- p.12 / Figure 1.1 Stages of mammalian erythropoiesis. Adapted from (Koury et al.,2002) --- p.13 / "Figure 1.2 Conversion of major ROS. Adapted from (Ghaffari," --- p.14 / Figure 1.3 Major oxidative defense in human erythrocytes --- p.15 / "Figure 1.4 Peroxide scavenging systems. Adapted from (Day," --- p.16 / Chapter 2 --- MATERIALS AND METHODS --- p.17 / Chapter 2.1 --- Cell culture --- p.18 / Chapter 2.1.1 --- Culture media --- p.18 / Chapter 2.1.2 --- Cell maintenance --- p.19 / Chapter 2.1.3 --- Cell cryopreservation --- p.19 / Chapter 2.1.4 --- Cell differentiation --- p.20 / Chapter 2.1.5 --- Cell treatments --- p.20 / Chapter 2.1.5.1 --- Antioxidant treatments --- p.21 / Chapter 2.1.5.2 --- H2O2 challenging --- p.22 / Chapter 2.1.5.3 --- Antibiotic treatment --- p.22 / Chapter 2.2 --- Flow cytometry --- p.23 / Chapter 2.2.1 --- Flow cytometers --- p.23 / Chapter 2.2.2 --- Analysis of erythroid differentiation --- p.23 / Chapter 2.2.3 --- Analysis of cell lineage --- p.24 / Chapter 2.2.4 --- Analysis of intracellular ROS --- p.24 / Chapter 2.2.5 --- Analysis of mitochondrial transmembrane potential (Δψm) --- p.25 / Chapter 2.2.6 --- Analysis of mitochondrial mass --- p.25 / Chapter 2.2.7 --- Analysis of cell death --- p.26 / Chapter 2.2.8 --- Analysis of caspase-3 activity --- p.27 / Chapter 2.2.9 --- FACS cell sorting --- p.27 / Chapter 2.2.10 --- Two-variant flow cytometric experiments --- p.28 / Chapter 2.2.11 --- Analysis of flow cytometry data --- p.28 / Chapter 2.2.12 --- Compensation --- p.29 / Chapter 2.2.12.1 --- Compensation matrix for Annexin V-PI double-staining --- p.29 / Chapter 2.2.12.2 --- Compensation matrix for Annexin V-TMRM double-staining --- p.30 / Chapter 2.2.12.3 --- Compensation matrix for CFSE- GPA double-staining --- p.31 / Chapter 2.2.12.4 --- Compensation matrix for CFSE- TMRM double-staining --- p.31 / Chapter 2.2.12.5 --- Compensation matrix for CM- H2DCFDA-GPA double-staining --- p.32 / Chapter 2.2.12.6 --- Compensation matrix for GPA- TMRM double-staining --- p.33 / Chapter 2.3 --- Western blot --- p.35 / Chapter 2.4 --- Statistical analysis --- p.37 / Chapter 3 --- RESULTS AND DISCUSSION --- p.38 / Chapter 3.1 --- The cells with high GPA staining were younger in cell lineage --- p.39 / Chapter 3.2 --- ROS was produced during TF-1 erythropoiesis --- p.40 / Chapter 3.3 --- ROS production was not essential for TF-1 erythropoiesis --- p.41 / Chapter 3.4 --- ROS production was not the cause of cell proliferation during TF-1 erythropoiesis --- p.41 / Chapter 3.5 --- ROS production was not the cause of sub-lethal mitochondrial depolarization in TF-1 erythropoiesis --- p.42 / Chapter 3.6 --- The cells showing mitochondrial depolarization were mother cells that gave rise to differentiating cells --- p.44 / Chapter 3.7 --- ROS production was not the cause of cell death in TF-1 erythropoiesis --- p.45 / Chapter 3.8 --- ROS production confers oxidative defense during TF-1 erythropoiesis --- p.47 / Chapter 3.8.1 --- Glut l inhibition partially blocked TF-1 erythropoiesis without affecting cell viability --- p.47 / Chapter 3.8.2 --- Antioxidant defense systems were established during TF-1 erythropoiesis --- p.48 / Chapter 3.8.3 --- Antioxidant treatments blocked the establishment of antioxidant defense systems during TF-1 erythropoiesis --- p.51 / Chapter 3.9 --- Conclusion --- p.55 / Chapter 3.10 --- Future work --- p.56 / Figure 3.1 Cell lineage versus erythroid marker during erythropoiesis under vitamin E treatment --- p.59 / Figure 3.2 ROS production during erythropoiesis --- p.60 / Figure 3.3 ROS production versus erythroid marker during erythropoiesis under vitamin E treatment --- p.61 / Figure 3.4 Percentage of ROS+ cells in vitamin E-treated TF-1 erythropoiesis as compared to control --- p.63 / Figure 3.5 Percentage of GPA+ cells in vitamin E-treated TF-1 erythropoiesis as compared to control --- p.64 / Figure 3.6 Cell death versus mitochondrial transmembrane potential (Δψm) during erythropoiesis under vitamin E treatment --- p.65 / Figure 3.7 Erythroid marker versus mitochondrial transmembrane potential (Δψm) during erythropoiesis under vitamin E treatment --- p.67 / Figure 3.8 Cell lineage versus mitochondrial transmembrane potential (Δψm) during erythropoiesis under vitamin E treatment --- p.69 / Figure 3.9 Change of mitochondrial mass during erythropoiesis --- p.71 / Figure 3.10 ROS production versus erythroid marker during erythropoiesis under levofloxacin treatment --- p.72 / Figure 3.11 Percentage of GPA+ cells in levofloxacin-treated TF-1 erythropoiesis as compared to control --- p.73 / Figure 3.12 Cell death versus mitochondrial transmembrane potential (Δψm) during erythropoiesis under levofloxac in treatment --- p.74 / Figure 3.13 Expression level of antioxidant enzymes during erythropoiesis --- p.75 / Figure 3.14 Expression level of Glut l during erythropoiesis --- p.76 / Figure 3.15 Expression level of Glut l in GPA positive and GPA negative populations --- p.77 / Figure 3.16 Cell death under oxidative stress challenging during erythropoiesis --- p.78 / Figure 3.17 Expression level of antioxidant enzymes and Glutl during erythropoiesis under EUK-134 treatment --- p.79 / Figure 3.18 Expression level of antioxidant enzymes and Glutl during erythropoiesis under vitamin E treatment --- p.80 / Figure 3.19 Cell death under oxidative stress challenging during erythropoiesis under vitamin E treatment --- p.82 / Figure 3.20 Expression level of antioxidant enzymes during erythropoiesis under vitamin C treatment --- p.83 / Figure 3.21 Cell death under oxidative stress challenging during erythropoiesis under vitamin C treatment --- p.84 / Figure 3.22 Cell death under oxidative stress challenging during erythropoiesis under NAC treatment --- p.85 / Figure 3.23 Summary of oxidative stress challenging during erythropoiesis --- p.86 / REFERENCES --- p.87
298

The implementation of nurse initiated and managed antiretroviral therapy in the City of Johannesburg clinics: perceived facilitators and barriers

Mophosho, Zanele 08 September 2015 (has links)
Research Report submitted in fulfillment of the requirements for the degree of Master in Public Health (MPH) at the University of the Witwatersrand. April 2015 / Introduction: Antiretroviral therapy (ART) is a lifesaving clinical intervention for people living with HIV (PLHIV). An important barrier to accessing therapy is the shortage of the health workforce particularly doctors. In order to mitigate the shortage, a nurse driven ART delivery approach known as Nurse Initiated and Managed Antiretroviral Therapy (NIMART) has been implemented in the public sector in South Africa and in other countries. NIMART enables professional nurses to initiate HIV positive persons on ART and manage their care at primary health care clinics. This study sought to explore and describe perceptions of operational managers, facility managers and professional nurses on the facilitators and barriers to the implementation of NIMART in the City of Joburg (CoJ) clinics. Methodology: This was an exploratory descriptive qualitative study which used in-depth interviews with a variety of respondents in order to gain insights into their perceptions of the implementation of NIMART in the CoJ clinics. In total, 26 respondents, comprising of operational managers, facility managers and professional nurses participated in the study. Thematic content analysis was used to analyse data drawing from the Donabedian structure-process-outcome framework. Results: The respondents identified the adequacy of NIMART training and mentoring; the availability and use of NIMART guidelines and the integration of NIMART into Primary Health Care (PHC) services as structural facilitative factors for NIMART implementation. The shortage of the health workforce, shortage of antiretrovirals (ARVs), poor referral feedback, food insecurity and the mobility of patients were identified as key structural and process barriers to the implementation of NIMART. Respondents perceived the improvement in quality of life of NIMART patients and the clinics’ ability to retain patients in care as indicative of the success of iii NIMART implementation. Finally, respondent’s suggestions for improving NIMART implementation in CoJ clinics focussed on improving shortage of the health workforce, improving the availability of ARV drugs and providing opportunities for continuing education for professional nurses. Discussion, conclusion and recommendations: In order to mitigate the barriers identified in this study, recommendations were that the City of Joburg should utilize lower level health care cadres such as nursing assistants and lay counsellors to reduce the professional nurses’ workload and thus improve access to treatment. In addition, the City of Joburg should revise the antiretroviral drug allocations to clinics and revise delivery schedules to ensure that clinics do not run out of ARV drugs. The referral feedback process should be strengthened through the referring clinic and the referral hospital jointly developing referral protocols that should be used by both institutions. Finally, the City of Joburg should consider conducting consultative discussions with professional nurses prior to introduction of new programmes and provide opportunities for regular updates for operational managers, facility managers and professional nurses. Future research could look at the role of PHC qualification in the implementation of NIMART.
299

Investigating the nature of dual active galactic nuclei in Stripe 82

Gross, Arran Connor 01 May 2019 (has links)
During the close approach of two galaxies in a merger, tidally induced gas inflows can trigger simultaneous black hole accretion which are observed as dual active galactic nuclei (dAGNs). Merger simulations predict that the resulting increased nuclear gas reservoirs will obscure the X-ray emissions from the AGNs. We investigate whether dAGNs in mergers are observed to be more obscured than their isolated counterparts by combining the results of previous radio and optical spectroscopy studies with new Chandra X-ray observations for a sample of 4 dAGN systems in the Stripe 82 field. For the 6 detected components, we find the rest-frame X-ray luminosities range between 39.8 < log LX /erg s-1 < 42.0. The sources have redshifts between 0.04 < z < 0.22 and projected separations between 4.3 and 9.2 kpc, as well as multi-wavelength properties most closely resembling low-luminosity AGNs. However, we determine that the X-ray emissions for 2 of the sources likely has strong contributions from hot interstellar medium, and star-formation and X-ray binaries may contribute to the X-ray luminosities of several sources. We do not find evidence of enhanced obscuration through our analysis of X-ray hardness ratios, optical [O III] emission line luminosities, and mid-infrared luminosities. Therefore, we suggest that the unobscured low-level accretion observed for the AGNs in this sample is driven through stochastic processes rather than the massive gas inflows predicted for a merger-driven scenario.
300

Non-Equilibrium Dynamics of Active Nematic Elastomers

Unknown Date (has links)
Active nematic elastomers are a class of active materials that possess the elasticity of a rubber, and the orientational symmetry of a liquid crystal. Their constituent elements are typically elongated, cross-linked and active. The cross-linking of the elements leads to an elasticity that prevents the material to ow like a liquid. These elements are active in a sense that they continuously consume and dissipate energy, creating a state that is far-from-equilibrium. Active nematic elastomers may be a good physical model for biological systems such as the metaphase spindle, a complex biological machine that is made of an integrated assembly of microtubules and molecular motors. These motors not only cross-link the microtubules, but also actively slide them against each other, creating a highly dynamic, non-equilibrium state. The metaphase spindle, like other non-equilibrium structures in biology, has important functions to perform. During mitosis, the spindle is responsible for (1) capturing the sister chromatids, (2) bringing all the sister chromatids to the equator of the mother cell, and (3) segregating the daughter chromosome to the opposite poles of the cell. Thus, a fundamental challenge to biological physics is to understand the complex dynamics of the spindle, and similar systems, using the tools of non-equilibrium statistical mechanics. In this Thesis, we develop and explore a phenomenological model for an active nematic elastomer. We formulate the dynamics of this phenomenological model by incorporating the contribution of the active elements to the standard formulation of the hydrodynamic equations of a passive system. In a coarse-grained picture, the activity is taken into account as an extra active stress, proportional to the alignment tensor, added to the momentum equation of an otherwise passive nematic elastomer. Having obtained the equations of motion of an active nematic elastomer, we then investigate the response of the system to an external field by means of examining the structure and the stability of the modes. An active nematic elastomer has eight modes, in which six modes are propagating and two modes are massive. Out of the six propagating modes, two modes are in the longitudinal direction, linked to the density waves, and the other four modes are in the transverse direction, linked to the shear waves. The nature of these propagating modes transitions from dissipative and oscillatory, and vice versa, depending on the length scales. In particular, their stability is largely determined in the hydrodynamic limit, by a competition between the stabilizing effect of the elasticity and the destabilizing effect of the activity. In fact, the activity renormalizes the elastic coefficients down to even a negative value in some cases and thus, rendering the system linearly unstable. This is in contrast to the well-known instability of an active nematic liquid crystal, which is always linearly unstable. We then map out and discuss the stability phase diagram of the active nematic elastomer. Next, we compute and study various equal-time correlation functions of an active nematic elastomer, assuming that the noise spectra are thermal in origin. We find that they can be conveniently arranged into two terms. The first term has the exact mathematical structure of the equal-time correlation functions of a passive nematic elastomer, albeit with certain coefficients renormalized by activity. The second term, which is proportional to the activity, represents the non-equilibrium nature of an active nematic elastomer, and manifestly breaks the Fluctuation-Dissipation Theorem. We also find that (1) the displacement-displacement correlation function decays inversely with the square of the wave number for both the compressible and incompressible nematic elastomer, similar to that of a passive nematic elastomer, with elastic coefficients renormalized by the activity. (2) The density-density correlation function approaches a constant at the long wave-length limit, since the conservation of mass links the density to the rate of changes of the displacement in the longitudinal direction. (3) The director-displacement correlation function is purely imaginary, and thus the director is locked to the displacement with a (π/2) phase-shift. (3) The director-director correlation function approaches a constant value in the long-wavelength limit, instead of decaying inversely with the square of the wave number, like it would for a liquid crystal. This is because of the massive mode stems from the coupling energy, and it indicates that director in the large length scale is locked to a specific angle. These theoretical results are in qualitative agreement with the experimental measurements of the spindle. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

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