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Correlations and entanglement in a chain of three oscillators A,B,C with nearest neighbour coupling is studied. Oscillators A,B and B,C are coupled but there is no direct coupling between oscillators A,C. Examples with initial factorizable states are considered, and the time evolution is calculated. It is shown that the dynamics of the tri-partite system creates correlations and entanglement among the three oscillators and in particular, between oscillators A,C which are not coupled directly. We have performed photon number selective and non-selective measurements on oscillator A and we investigated their effects on the correlations and entanglement. It is shown that, before the measurement, the correlations between oscillators A,C can be stronger than the correlations of oscillators A,B. Moreover, some entanglement witness shows that oscillators A,C are entangled but the oscillators A,B might or might not be entangled. By using quantum discord, which measures the quantumness of correlations, it is shown that there are quantum correlations between oscillators A,B and after the measurements in both cases of selective and non-selective measurements, oscillators A,B and A,C become classically correlated.

Correlations and entanglement in a chain of three oscillators A,B,C with nearest neighbour coupling is studied. Oscillators A,B and B,C are coupled but there is no direct coupling between oscillators A,C. Examples with initial factorizable states are considered, and the time evolution is calculated. It is shown that the dynamics of the tri-partite system creates correlations and entanglement among the three oscillators and in particular, between oscillators A,C which are not coupled directly. We have performed photon number selective and non-selective measurements on oscillator A and we investigated their effects on the correlations and entanglement. It is shown that, before the measurement, the correlations between oscillators A,C can be stronger than the correlations of oscillators A,B. Moreover, some entanglement witness shows that oscillators A,C are entangled but the oscillators A,B might or might not be entangled. By using quantum discord, which measures the quantumness of correlations, it is shown that there are quantum correlations between oscillators A,B and after the measurements in both cases of selective and non-selective measurements, oscillators A,B and A,C become classically correlated. / Ministry of Higher Education, Malaysia and Universiti Kebangsaan, Malaysia.

The implications of chain topology and intermolecular interactions on the electrospinning process were investigated for linear and randomly branched polymers. Empirical correlations were developed based on solution rheological measurements that predict the onset of electrospun fiber formation and average fiber diameter. In particular, for neutral, non-associating polymer solutions, the minimum concentration required for fiber formation was the entanglement concentration (Ce), and uniform, bead-free fibers were formed at 2 to 2.5 Ce. This was attributed to entanglement couplings stabilizing the electrospinning jet and preventing the Raleigh instability. Moreover, the influence of molar mass and degree of branching on electrospun fiber diameter was eliminated when the polymer concentration was normalized with Ce, and the fiber diameter universally scaled with C/Ce to the 2.7 power. Polymers modified with quadruple hydrogen bonding groups were investigated to determine the role of intermolecular interactions on the solution rheological behavior and the electrospinning process. In nonpolar solvents, the hydrogen bonding functionalized polymers displayed significant deviation from the electrospinning behavior for neutral solutions due to the strong intermolecular associations of the multiple hydrogen bonding groups. The predicted electrospinning behavior was recovered when the hydrogen bonding interactions were screened with a polar solvent. Moreover, it was observed that branching and multiple hydrogen bonding afforded significant processing advantages compared to functionalized, linear analogs of equal molar mass. For example, branched chains in the unassociated state possessed a larger Ce compared to the linear chains, which indicated a lower entanglement density of the former. However, in the associated state the linear and branched chains possessed nearly equivalent Ce values, suggesting a similar entanglement density. Thus, the branched polymers displayed significantly lower viscosities in the unassociated state compared to linear polymers, while still retaining sufficient entanglements in the associated state due to the reversible network structure of the multiple hydrogen bond sites. The solution rheological and processing behavior of polyelectrolyte solutions was also investigated to discern the role of electrostatic interactions on electrospun fiber formation. In particular, the polyelectrolyte solutions formed nano-scale electrospun fibers with an average fiber diameter 2 to 3 orders of magnitude smaller than neutral polymer solutions of equivalent viscosity and C/Ce. This was attributed to the very high electrical conductivity of the polyelectrolyte solutions, which imparted a high degree of charge repulsion in the electrospinning jet and increased the extent of plastic stretching in the polymer filament. In fact, the average diameter of the polyelectrolyte fibers under certain conditions was less than 100 nm, which makes them good candidates for protective clothing applications due to their high specific surface area. Moreover, the neutral polymer solution electrospinning behavior was recovered after the addition of NaCl, which screened the electrostatic charge repulsions along the polyelectrolyte main chain. Finally, electrospun, biocompatible phospholipid membranes were produced from solutions of entangled worm-like lecithin micelles. This is the first example of successfully electrospinning low molar mass, amphiphilic compounds into uniform fibers. Electrospinning the phospholipid worm-like micelles into nonwoven fibrous mats will afford direct engineering of bio-functional, high surface area membranes without the use of multiple synthetic steps, complicated electrospinning setups, or post processing surface treatments. / Ph. D.

The theoretical movement known under the heading of posthumanism has entered the academic field. Posthumanisms most prominent feature is to retrieve the concept of matter into the analytical framework. Matter is understood to be under-theorized within the social sciences as a result of the permeative focus upon language and discourse. A prevailing understanding of posthumanism that has been used within educational science and philosophy thus consists of moving the searchlight from language/discourse onto matter. Notably, these scholars are turning to the philosopher Karen Barad in order to spell out their posthumanistic implications. The aim of the thesis is to give an account of the philosophy of Karen Barad in contrast to other prevailing renderings of her. The analysis is carried out using a contrastive methodological approach. In this study I demonstrate how my reading of Barad differs from the scholarly readings that I choose to engage with. The results show that with an alternative conceptual understanding of Barad’s posthumanistic theory the analysis is being steered towards the entanglement of matter and discourse rather than towards the materialistic components of a posed problem. In addition, the results also show how a focus on the ontological underpinnings of Barad’s theoretical framework can give crucial contributions when it comes to understanding the generative conditions of science and knowledge-making.

L’objectif de cette thèse est d’observer la modification du comportement rhéologique dedifférents polyéthylènes branchés, suite à un traitement de cisaillement. Après avoir décrit lesmatériaux et les moyens utilisés, nous avons caractérisé le plus complètement possible lecomportement rhéologique des différents matériaux, aussi bien en cisaillement qu'en élongation.Nous avons également déterminé des données calorimétriques et des informations sur lescaractéristiques moléculaires, permettant entre autres de définir la masse entre enchevêtrements.Nous avons ensuite mesuré l’évolution de la viscosité dans différentes conditions de pré‐cisaillement,en faisant varier le temps et le taux de cisaillement dans un rhéomètre cône‐plan et dans unegéométrie de Couette montée en amont d’un rhéomètre capillaire. Nous avons montré que lesmécanismes de désenchevêtrement sont complexes et qu'ils ne sont pas directement explicables parun seul paramètre, comme la masse entre enchevêtrements. Enfin, l’observation des extrudats à lasortie de la filière nous a permis de mettre en évidence la modification des défauts d'extrusion sousl’effet d’un pré‐cisaillement. / The aim of this work is to characterize the effects of shear modification on differentbranched polyethylenes. After a short description of materials and methods, we have characterizedthe rheological behaviour of the different materials, both in shear and elongation. We have alsoobtained calorimetric and molecular data, allowing us to define the molar mass betweenentanglements. Then, we have characterized the viscosity changes induced by a pre‐shear, indifferent conditions of shear rate and time, both in cone and plate and Couette geometries. We haveshown that the mechanisms of disentanglement are complex and cannot be directly explained by aunique parameter like the mass between entanglements. Finally, the observation of the extrudatesat the die exit has permitted to evidence the change in extrusion defects induced by shearmodification.

Environmental stress cracking (ESC) is one of the main, and probably the most common, failure mechanisms involved in polymer fractures. This type of failure is critically important as it occurs suddenly, without any visible pre-fracture deformation. Such failure can be catastrophic and costly in cases where structural integrity is required. In polyethylene (PE), ESC occurs through a slow crack growth mechanism. Cracks initiate from stress-concentrated imperfections, propagate through the bulk of PE, and ultimately result in a brittle fracture. In order to predict the environmental stress cracking resistance (ESCR) of PE, it is necessary to fully understand the molecular structure of the resin. In this thesis, attempts were made to find relationships between molecular structure characteristics and material responses, mainly inter-lamellar entanglements and strain hardening behaviour of PE resins, through mechanical and rheological experiments. Inter-lamellar entanglements are believed to be the main factor controlling slow crack growth of PE. Extent of entanglements and entanglement efficiency were investigated by monitoring the strain hardening behaviour of PE resins in the solid state through a uniaxial tensile test, and in the melt state, through extensional rheometry. ESCR is usually assessed by unreliable and time consuming testing methods such as the notch constant load test (NCLT) on notched PE specimens in the presence of an aggressive fluid and elevated temperatures. In this thesis, a practical, yet reliable, tensile test was developed for the evaluation and prediction of ESCR. The developed test offers a more reliable and consistent ESCR picture without the drawbacks of the subjective notching process and presence of aggressive fluids. Through this test, a factor called ???corrected hardening stiffness (cHS)??? was developed, which can easily be used for a relative ranking of ESCR of different PE resins. Studies were next extended to the melt state via shear and extensional rheometry. Through studies in the shear mode, a molecular weight-normalized average characteristic relaxation time (??N) was found to be efficient in predicting the extent of chain entanglements in resins. This provided a potential melt indicator for a relative measure of ESCR, for linear low density polyethylene (LLDPE), with different short chain branching levels. Extensional studies were conducted to evaluate the strain hardening behaviour in the melt state. An inverse correlation was obtained between ESCR and the melt strain hardening coefficient (MSHC), found from Sentmanat Extensional Rheometry (SER). This indicated an inverse relationship between ESCR and chain extensibility in the melt. In addition, a new factor called ???melt hardening stiffness (mHS)??? was developed from the slope of a stress-strain line, obtained from SER. This factor, analogous to cHS, can be used for a practical and reliable ranking of ESCR of PEs. ESCR is usually associated with classical crystalline phase property indicators, such as crystallinity and lamella thickness. In this thesis, the effect of processing and post processing temperature on the extent of inter-lamellar entanglements were investigated, evaluated, and correlated to ESCR. Also, analysis of the lamella surface area (LSA) was pursued since LSA reflects changes in phase interconnectivity more precisely. The focus of this part of the study was on the effect of temperature on LSA to identify the optimum processing and post-processing conditions which yield a higher LSA. It was reasonable to presume that PE with larger lamella lateral surface areas will have more inter-lamellar entanglements, hence higher ESCR. Finally, a well-controlled ultraviolet (UV) photoinitiated reactive extrusion (REX) process was developed for selective formation of long chain branches in the PE structure. This was conducted to impose restrictions against stretching of the polymer chain, which consequently enhanced ESCR.

In a cultural web of myth, sexualisation and prejudice, how do older, British singletons gain access to health-giving, non-sexual touch? This study takes interview material from five single women and three single men (all cisgender, white, heterosexual, British, between 37-76 years) and interlaces it with autoethnographic commentary, poems and artworks to explore negotiations around touch. Drawing on Haraway and Barad’s theoretical concept of “entanglements” (2008; 2007), cross-disciplinary connections are woven across feminist new materialism and social sciences, the body and discourse, the conscious and subconscious. Findings, which are partial, provisional, messy and complex (Haraway 1988), include powerful narratives of shame, denial and cauterisation of touch-needs. These co-exist with corporeal tales of the richness and variety of touch-opportunities, the tactile importance of cats and a “turn” by the oldest, female participants away from a romantic, heterosexual partner towards bonding with the landscape.

This thesis explores the dimensions of an emerging design space in the Anthropocene through a design process that embraces Probology as a method to integrate interdisciplinary research in exploring and implementing solutions to the dissociation of urbanites from Earth’s ecological community.

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