Solubilisation, Purification and Processing of Single Walled Carbon Nanotubes Using Organic Molecules

The aims of this research are seven fold; • To enhance the solubility of SWNTs in organic solvents. • To purify an untreated sample of SWNTs that contains many side products. • To gain a greater understanding of the interaction between the polycyclic aromatic hydrocarbons and SWNTs. • To debundle and disperse SWNTs. • To select SWNTs of a specific structure based on the structures of the polycyclic aromatic hydrocarbons used. • To observe and compare the interaction of polycyclic aromatic hydrocarbons with SWNTs produced by different methods. • To elucidate factors which contribute to different degrees of interaction between different SWNT samples and the hydrocarbon molecules. In this research, the solubilisation, purification and debundling of single walled carbon nanotubes (SWNT) on interaction with the polycyclic aromatic hydrocarbons (PAHs), anthracene and p-terphenyl are explored. The investigations were performed in toluene due to its poor affinity for the retention of SWNTs. Thus this solvent can act as a good indicator for improvements in the solubility of the SWNTs due to the presence of the PAHs. The hydrocarbons anthracene and p-terphenyl were chosen because of their high degree of solubility in toluene and their simple structure that is proposed in this research to exhibit molecular recognition of SWNTs with a similar backbone structure to that of the hydrocarbon. The study begins with the exploration of the interaction between the SWNTs in an untreated sample and the PAHs, and results reveal an enhanced solubility of the SWNTs in toluene and subsequently the purification of the SWNT sample. Interaction between the PAHs and the SWNTs draws the SWNTs into solution allowing all side products to precipitate out. The composite solution is a stable suspension of finely dispersed SWNTs with no evidence of SWNT precipitation observed in over a five year period. This observation indicates an enhanced stability of the SWNTs in solutions due to an interaction with the PAH molecules and this observation is supported by Raman and fluorescence spectroscopic studies which are presented in this thesis. Both anthracene and p-terphenyl map via a π - π interaction to the SWNT backbone with strong indications of structural selectivity between the SWNT surfaces and PAHs. The literature is scarce with regard to the interaction between organic molecules and SWNTs. In this research an investigation into the interaction that occurs between PAHs and SWNTs is conducted. The interactions and debundling of SWNTs over a broad concentration range are probed through spectroscopic methods including fluorescence and Raman. Fluorescence concentration dependence studies define the concentration range where aggregated PAHs and isolated PAHs exist. A fluorescence model based on the fraction of free hydrocarbons is used to indicate the concentration range where debundled and bundled SWNTs and PAHs are interacting with atomic force microscopic (AFM) studies supporting the results. AFM is used to obtain a surface profile of the SWNTs at a range of concentrations to image the debundling of SWNTs with decreasing concentration. The fluorescence model also allows the calculation of a binding energy between the SWNTs and PAHs at low concentrations. The binding energy determined is further supported by alternative theoretical models and the results obtained correlate well. Raman studies support fluorescence and AFM studies with regard to the interaction and debundling of SWNTs and the Raman radial breathing modes (RBMs) are probed to investigate selective interaction of the RAH molecules at low concentrations and results reveal a degree of selective interaction. To conclude this work, a study of SWNTs produced by different methods is performed to investigate any changes which may occur to the SWNT/PAH/solvent system as a result of replacing one tube type for another. The study elucidates factors that are favourable for interaction with the hydrocarbon in the given solvent toluene. Spectroscopic methods such as fluorescence and microscopic studies such as AFM are used as the investigative tools. The studies reveal that large bundles with larger diameter SWNTs are most favourable for interaction with p-terphenyl and debundling in toluene. Such a study is of interest for the development of a standardised purification and processing protocol

The phenomenal brain : making room for a phenomenal-neural type identity theory of phenomenal consciousness

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 25, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Andrew Melnyk.Vita.Ph. D. University of Missouri--Columbia 2008.It is currently popular among physicalist philosophers of mind to suppose that phenomenal consciousness is essentially a representational phenomenon and that a representational theory of phenomenal consciousness will prove to be the best sort of reductive theory physicalists can offer. In my dissertation I take steps to show that this is not the case and suggest that a phenomenal-neural type identity theory should be the preferred physicalist theory of phenomenal consciousness. Specifically, I consider the prospects for Michael Tye's PANIC theory. The PANIC theory is the most fully developed, and perhaps most promising, representational theory of phenomenal consciousness to date. The main thesis of Tye's theory is the reductive claim that phenomenal character is one and same as a certain sort of representational content. Tye argues for this thesis by appealing to its explanatory power. I show, however, that the thesis in question is inessential to the relevant explanatory features of the PANIC theory and that phenomenal-neural type identity theory, when supplemented with those features, enjoys all the explanatory benefits the PANIC theory. Furthermore, I argue that the PANIC theory cannot adequately account for how phenomenal character could be causally relevant to behavior, which is a problem the phenomenal-neural type identity theory easily avoids. Though these considerations alone may not establish the superiority of the phenomenal-neural type identity theory over that of that of the PANIC theory, I hope to demonstrate that the phenomenal-neural type identity approach to reducing phenomenal consciousness has much more going for it than is typically acknowledged and that the phenomenal-neural type identity theory I develop is a serious rival to the PANIC theory.Includes bibliographical reference

A Comparative Study of the Interaction of Different Polycyclic Aromatic Hydrocarbons on Different Types of Single Walled Carbon Nanotubes

A comparative study of the solubilising effect of polycyclic aromatic hydrocarbon (PAHs) on single walled carbon nanotubes (SWCNTs) produced by high pressure decomposition of carbon monoxide (HiPco) and the arc discharge (AD) method has been carried out with the aid of fluorescence and Raman spectroscopy. For this study, polyphenyl and polyacene PAHs of different lengths are used. From the study it has been found that the binding energy of PAHs with AD SWCNTs is the same as that with HiPco SWCNTs. Shorter PAHs molecules better solubilise SWCNTs and in general smaller diameter SWCNTs. Thus, given their smaller diameter profile, significantly larger amounts of HiPco SWCNTs are solubilised than AD SWCNTs

The Effects of Digital Storytelling on Student Learning and Engagement in the Secondary World Language Classroom

This action research study involved the development and enactment of a unit in a secondary French world language classroom using digital storytelling. The main purpose of this study was to examine the effects of digital storytelling on student engagement and language acquisition through the design and employment of a unit using digital storytelling software. Digital storytelling was chosen for its modern influence of narrative customization using digital features such as voice recordings, video clips, images, and music. In addition, other components were identified including multiple drafts, peer-collaboration, and student-choice. The secondary purpose of this study was to address the importance of teacher expertise and self-efficacy in using technology to effectively employ digital storytelling within a unit through researcher self-refection. This action-research study provided notable findings that supported the need of incorporating digital storytelling in the classroom. Although there were a variety of student responses to the project, the results indicate that students were highly-engaged throughout the unit as they demonstrated proficiency in language acquisition. Critical components of the unit consisted of multiple modes of communication, mini-lessons, and student work. Digital storytelling works in tandem with the school’s goal of innovation in the classroom through modern pedagogical choices. To that end, digital storytelling addresses the disconnect between the necessary student engagement in language acquisition and the traditional, decontextualized instructional methods still used in many world language classes. The principal language learning goals of this project include the correct usage of the passé composé of reflexive verbs with contextual vocabulary to communicate about one’s daily routine

Developments for a Swept Wing Airfoil to Study the Effects of Step and Gap Excrescences on Boundary Layer Transition

Skin friction drag reduction is one of the most promising paths in the investigation of the reduction of aircraft fuel burn. 40 – 50% of overall drag comes from the surfaces of the wings and stabilizers. Natural laminar flow airfoils can extend the region of laminar flow and reduce skin friction drag. However, real-world aircraft wings do not have perfectly smooth surfaces, and therefore the tolerances for step and gap excrescences on these airfoils must be investigated. Previous work has focused on excrescences on flat plates, and only recently included pressure gradient effects. A new three-dimensional swept wing airfoil with an actuated leading edge (SWIFTER) has been constructed, and will extend the body of knowledge of step and gap excrescences to a more real-world configuration and higher Reynolds numbers. An integrated control system for the leading edge actuation system is proposed, including both interface hardware and control code. A heating system for the test surface is also discussed, and the controller hardware, sensors, and code specified. For wind tunnel testing, a proposed set of wall liners are developed from zero-lift condition streamlines and divided into parts suitable for manufacturing, assembly, and installation. Finally, preliminary wind tunnel step excrescence tests using an existing swept-wing model and applique step material were conducted, and the results are discussed with relevance to testing on the new model

The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review

High carbohydrate intakes are commonly recommended for athletes of various sports, including strength trainees, to optimize performance. However, the effect of carbohydrate intake on strength training performance has not been systematically analyzed. A systematic literature search was conducted for trials that manipulated carbohydrate intake, including supplements, and measured strength, resistance training or power either acutely or after a diet and strength training program. Studies were categorized as either (1) acute supplementation, (2) exercise-induced glycogen depletion with subsequent carbohydrate manipulation, (3) short-term (2–7 days) carbohydrate manipulation or (4) changes in performance after longer-term diet manipulation and strength training. Forty-nine studies were included: 19 acute, six glycogen depletion, seven short-term and 17 long-term studies. Participants were strength trainees or athletes (39 studies), recreationally active (six studies) or untrained (four studies). Acutely, higher carbohydrate intake did not improve performance in 13 studies and enhanced performance in six studies, primarily in those with fasted control groups and workouts with over 10 sets per muscle group. One study found that a carbohydrate meal improved performance compared to water but not in comparison to a sensory-matched placebo breakfast. There was no evidence of a dose-response effect. After glycogen depletion, carbohydrate supplementation improved performance in three studies compared to placebo, in particular during bi-daily workouts, but not in research with isocaloric controls. None of the seven short-term studies found beneficial effects of carbohydrate manipulation. Longer-term changes in performance were not influenced by carbohydrate intake in 15 studies; one study favored the higher- and one the lower-carbohydrate condition. Carbohydrate intake per se is unlikely to strength training performance in a fed state in workouts consisting of up to 10 sets per muscle group. Performance during higher volumes may benefit from carbohydrates, but more studies with isocaloric control groups, sensory-matched placebos and locally measured glycogen depletion are needed.publishedVersio

Enhancing Feedback: key Issues and Solutions From the Literature to Help New Lecturers in Higher Education

The National Strategy for Higher Education to 2030 highlights that whilst modularisation has allowed for greater flexibility, it has also produced some problems including fragmentation of programmes with large numbers of modules leaving students feeling over assessed and staff burdened (Hunt, 2011). Nicol & Macfarlene-Dick (2006) have argued that formative assessment can promote better student learning and that assessment can be used more effectively by embedding ‘feedback’ and ‘feedforward’ in curriculum practices. Their studies identify how formative feedback does not have to solely come from the teacher, but can also be provided by peers and even generated by the students themselves. The Irish National Forum for the Enhancement of Teaching and Learning in Higher Education (NFETLHE) has put forward similar arguments to enhance learning if we move away from a purely ‘Assessment OF’ approach and shift towards a more ‘Assessment FOR’ and ‘Assessment AS Learning’ approach, giving the students a more central role (NFETLHE, 2017). Figure 1 below illustrates these concepts and highlights the dynamic relationship between formative assessment and learning (NFETLHE, 2017)

'We have no awareness of what they actually do': Magistrates' knowledge of and confidence in community sentences for women offenders in England and Wales

In its Strategic Objectives for Female Offenders (2013) the Coalition government reiterated its support for robust and effective sentencing options that enable the majority of non-violent women offenders to be punished in the community. While a laudable ambition, this strategy will only be successful if sentencers are aware of (and support) the options available to achieve this goal. Considering government policy in relation to current levels of awareness among the magistracy, this article explores the factors that influence sentencing decisions for women. Highlighting reservations about the suitability of community provision, it also reveals the lack of information and training that magistrates receive on this issue. While there is certainly a willingness to learn and consider more creative options when sentencing women, it is clear that better knowledge of the offender and the options available are needed. Drawing on empirical research conducted with 168 magistrates in England and Wales, this article concludes with a number of practical avenues for improved communication, advocated by magistrates themselves. With many unaware of strategic direction on this issue, the implications for policy and practice are obvious

Sentencing Women in the Transformed Probation Landscape

In 2013 the government promised that new reforms would ‘deliver better outcomes for women offenders’ (Ministry of Justice, 2013b, p.16). This was a bold statement and a laudable ambition. However, this strategy – called and aimed at Transforming Rehabilitation - will only be successful if sentencers are aware of (and support) the options that new providers put in place to achieve its goals. This chapter considers current levels of awareness of the new reforms among magistrates. Highlighting reservations about the suitability of community provision, and a lack of awareness about developments under Transforming Rehabilitation, it emphasises the lack of information that magistrates receive on this issue. Supplementing the findings of a recent research project conducted with 168 magistrates (see Birkett, 2016), this chapter provides a post-Transforming Rehabilitation ‘update’, drawing on 24 semi-structured interviews and a survey of 86 magistrates sitting across England and Wales. As such, it places particular focus on developments that followed the implementation of the Offender Rehabilitation Act 2014, the legislative measures underpinning the government’s flagship Transforming Rehabilitation policy agenda