Despite the poor understanding of charge transfer in conducting polymers, conducting-polymer-based devices have achieved considerable commercial success. This success is based largely on the reproducibility of the measurable properties. It is the purpose of this study to further clarify charge transfer characteristics of conducting polymers under varying conditions. We studied a conducting polymer called polyaniline. Polyaniline was available in its doped conducting form called emeraldine salt and in its undoped form called emeraldine base. Three types of polyaniline were studies, electrosynthesized (doped by HCI), chemically synthesized (doped by HCI) and commercial polyaniline obtained from Adlrich Company and doped by camphor sulfonic acid. Initially we investigated whether charge transfer was ionic or electronic by observing the change in resistance with time for a fixed applied current. It was concluded that condition in this material is electronic. Electrical measurements were obtained using the four-point probe and the Montgomery methods. The samples investigated were in pellet and film forms. We investigated charge transfer over the temperature regime 30-450 K by applying the following methods: scanning electron microscopy to investigate the surfaces of pellet and film samples, Fourier transform infrared spectroscopy and Raman spectroscopy to investigate the effect of annealing on the molecular structure of the polymer and thermal analysis to investigate the loss of substances from the polymer as a result of the annealing process. The conductivity of the material was also analyzed over the entire temperature regime. The following were observed: • Conductivity in polyaniline is governed my monomer units. • The decrease in conductivity with increase annealing temperature is related to moisture loss, loss of dopant ions and polymer degradation. • The variable range hopping model in three dimensions, satisfactorily describes charge transfer mechanism in polyaniline. • Conductivity in polyaniline is temperature activated. • Conductivity varies with position on the sample surface. • The effect of pellet pressing pressure to conductivity is negligible. • Current-voltage characteristics for polyaniline exhibit non-ohmic behavior at high current values, (>0.2 mA for T <80 K), applied between the current probes of a four-point probe measuring instrument. / Dissertation (MSc (Physics))--University of Pretoria, 2006. / Physics / unrestricted

Soundpainting is the method of "live composition" invented by New Yorkbased composer and saxophonist Walter Thompson. Using physical gestures for the spontaneous creation of music, Soundpainting therefore shares similarities with other types of gesture-based systems for music performance, such as orchestral conducting. Thompson himself (2006) describes his Soundpainting system as a "universal live composing sign language for the performing and visual arts," and therefore Soundpainting can be considered as a subset of other communication systems such as verbal and written language, kinesics, and paralanguage. This thesis outlines the general principles of Soundpainting as a system for setting into motion spontaneously created music. The author's aim is to describe Soundpainting in relation to the linguistic turn in Thompson's own definition. This opens the way to a sociosemiotic analysis, in which it is susceptible to examination in the light of some theories of language that have emerged in the course of the twentieth century. A theoretical framework is developed drawing on the work of such pioneers of semiotics as Saussure and Peirce, as well as the later work in philosophy of language of Wittgenstein, Barthes, Eco, Derrida, and others. The eclectic concerns of Soundpainting suggest situating Thompson's language in the context of current debates in critical theory about tonality, jazz, and improvisation as strategies for constructing identity. Soundpainting, by demonstrating that musical signification can be negotiated through consensus, problematizes the convention of the composer as the sole legitimating authority of the work. Considering Soundpainting as a processual activity, this dissertation outlines the general principles of Soundpainting as a system for the spontaneous creation of music. Emphasizing the process-based character of Soundpainting (and its affinity with other forms of improvised music) suggests that such categories of musical activity need to be studied from a different vantage point from that of historical musicology. / Thesis (PhD (Music))--University of Pretoria, 2007. / Music / PhD / unrestricted

Derivados do politiofeno são promissores para obtenção de sensores ópticos devido as suas propriedades crômicas, enquanto que polímeros azosubstituídos (azopolímeros) têm sido estudados para várias aplicações, tal como memórias ópticas. Neste trabalho procurou-se unir as propriedades dos derivados politiofênicos as dos azopolímeros através da preparação de um polímero tiofênico azosubstituído, obtido pela funcionalização do monômero tiofênico com um grupo azobenzênico. Para fins de comparação, foram também sintetizados um derivado polialquiltiofeno, o poli(3-octiltiofeno), e um copolímero formado a partir da união dos monômeros 3- octiltiofeno e do tiofeno azosubstituído. A obtenção do monômero azosubstituído foi feita a partir de uma reação de esterificação entre o ácido 3-tiofeno acético e o corante comercial vermelho disperso 1 (disperse red 1, DR1), ao passo que o monômero alquilado foi adquirido comercialmente. Os polímeros foram sintetizados por polimerização oxidativa com cloreto fénico e caracterizados químicoestruturalmente pelas técnicas de FTIR, 1H RMN, análise elementar, HPSEC e análise térmica (TG e DSC). Dessas análises comprovou-se a formação dos homopolímeros, mas não foi possível confirmar a formação do copolímero e ainda para esse caso, obteve-se uma menor quantidade de unidades azosubstituídas do que a pretendida. A análise da fotoluminescência destes materiais mostrou a influência do tipo de cadeia lateral na intensidade e no formato do espectro de emissão desses polímeros. A espectroscopia de UV-Vis foi utilizada para o estudo de suas propriedades crômicas, sendo observada a presença de termo- e solvatocromismo. O termocromismo foi analisado em solução e na forma de filmes e o solvatocromismo em soluções de solventes puros e em misturas de THF/ n-hexano com diferentes proporções. Esses polímeros também apresentaram alterações em seus espectros de absorção como resposta à variação do pH da solução. A birrefringência fotoinduzida, técnica de estudo visando a aplicação dos polímeros em memórias ópticas, somente foi observada para o homopolímero azosubstituído. Os resultados obtidos neste trabalho indicam que o politiofeno azosubstituído é um candidato promissor para elemento ativo em uma série de aplicações, tais como sensores de diversos tipos e em dispositivos de marcação oculta / Polythiophene derivatives are promising for optical sensors due to their chromic properties while azofunctionalized polymers have been used in several applications such as optical memories. In this work, an azosubstituted polythiophene was prepared by the functionalization of the thiophenic monomer with an azobenzene moiety in order to combine the polythiophene properties with those from the azopolymers. For the sake of comparison, a polyalkylthiophene, the poly(3- octylthiophene), and a copolymer of 3-octylthiophene and the azothiophene were synthesized. The azosubstituted monomer was synthesized by the esterification reaction of 3-thiopheneacetic acid and the commercial dye Disperse Red 1 (DRI), whilc the alkyl thiophene monomer was purchased. The polymers were prepared by oxidative polymerization reactions with ferric chloride and characterized chemically and structurally using FTIR, 1H NMR, elemental analysis and thermal analysis (TG and DSC) techniques. From these analyses, the formation of homopolymers was confirmed, but it was not possible to confirm the formation of the copolymer. In the latter, the amount of azosubstituted units was smaller than expected. The analysis of the polymers photoluminescence showed the influence of the side chain in the intensity and shape of the emission spectra. UV-Vis spectroscopy was used to study the polymer chromic properties which showed thermo- and solvatochromism. Thermochromism was analyzed in solution and in thin solid films and the solvatochromism was studied in pure solvent solutions and mixtures of THF/hexane in different ratios. These polymers also had their absorption spectra affected by changing the concentration of a protonic acid (HCI) solution. Photoinduced birefringence, aiming at optical memories applications, was only observed for the azosubstituted homopolymer. The overall results indicate that the azosubstituted polythiophene is promising as active material for several applications, such as different types of sensors and security-labeling devices

High school band members (N=13) and their teacher were observed during six rehearsals of two contrasting band compositions over a six-week period. The contrasting compositions were selected by means of a detailed process between me (the researcher) and the teacher (the conductor). One 60-second excerpt of each composition was selected, during the performance of which, the students were observed. Three video tapings of each composition was done in order to capture occasions when the students would look up from their music. Using a technique adapted from Ekman (1997), the band members and teacher were then interviewed in order to reveal the reasons they recalled for looking up from their music. The results showed that the band members looked up in places where the teacher expected eye contact, that the frequency of eye contact changed little from one rehearsal to the next, and that the frequency of eye contact changed little between the two contrasting compositions. In all cases, the band members were able to recall the reasons for looking up from their music, a fact which led to a detailed analysis about the students' own thoughts while they were engaged in playing as an ensemble. The results are discussed in terms of strategies for teaching practice and implications for future research.

The Czech-born music theorist, Václav Philomathes, wrote the Musicorum libri quattuor in 1512 while attending the University of Vienna. This didactic treatise became one of the most widely published theory treatise of its time with 26 copies of five editions remaining today and covers the topics of Gregorian chant practice, Solmization, Mensural Notation, Choir Practice and Conducting, and Four-voice Counterpoint. Of particular note, is the section on choir practice and conducting, of which there is no equivalent prior example extant today. This dissertation provides a Latin-English translation of Philomathes’s work, as well as produces a critical commentary and comparison of the five editions while positioning the editions within the context of the musico-theoretical background of early-to-mid-16th century scholarship in Central Europe.

Conducting gestures and facial expressions can be interpreted with wide variance by musicians, even within ensembles with a close range of technical mastery and experience. In this study, I examined the interpretations of a music conductor’s nonverbal communication to collegiate wind ensemble students and the accompanying pedagogical considerations when leading live performers. The conceptual framework of the study was kinesics, “the study of body movements, facial expressions, and gestures” (Ottenheimer, 2009, p. 160), and more specifically, Ekman and Friesen’s (1969) categories of nonverbal communication. Within this framework, the two categories I used specifically were emblems- nonverbal signals from the body representing a verbal message, and affect displays- characterizations of an emotion or other message depicted primarily on the face. Utilizing gesture descriptions compiled by Sousa (1988), I created a video stimulus to interview students on their reactions to 21 gestures of the hands, arms, and torso, as well as 10 naturally occurring facial expressions while conducting. Using the conducting video as the stimulus, I interviewed 80 college students at nine college campuses. Students participated in an individual 30-minute interview where they watched each of the 31 video excerpts and gave verbal feedback about what they perceived as the message of each of the gestures or facial expressions. Data were analyzed and compared to Sousa’s (1988) descriptions of each gesture from which the conductor attempted to demonstrate on the video. Utilizing Ekman and Friesen’s (1969) metric of 70% recognition to code a response as an emblem, 16 of the 21 gestures (76%) were discovered to be musical emblems, compared to 71% in Sousa’s (1988) study. Only 12 out of 21 gestures were identified as emblems in both studies (57%). Categories of the strongest prevalence in the current study of emblems included dynamics and tempo changes. Results from the 10 videos of facial expression netted more than ten different themes per affect display, each with diverse descriptions of musical and emotional messages. Overall results showed the small muscle movements of the face are capable of multi-message and multi-signal semiotic functions (Ekman & Friesen, 1978) with robust descriptions that can change rapidly in significant ways.

Smart skins are integrating an increasing number of functionalities in order to improve the interaction between the systems they equip and their ambient environment. Here we have developed an electromechanical soft actuator with controlled surface texture due to applied thermal gradient via electrical voltage. The device was fabricated and integrated with optimized process parameters for a prepared heater element [doped PEDOT: PSS (poly-(3, 4 ethylenedioxythiophene): poly (styrene sulfonic acid))], a soft actuator (Ecoflex 00-50/ethanol) and overall packaging case [PDMS (polydimethylsiloxane)]. To study a potential application of the proposed smart skin, we analyze the fluid drag reduction in a texture controlled water flow unit. As a result, we obtained a reduction of approximately 14% in the skin drag friction coefficient during the actuation. We conclude that the proposed soft actuator device is a preferred option for a texture-controlled skin that reduces the skin drag friction coefficient.

The aim of this master's thesis is to explore and elaborate on the Wagnerian conception of "tempo modification" and its overall relevance in the temporal shaping of music in orchestral conducting. The argument is based on a study that aims to revitalise and establish the tempo identification as a conductor's primary area of interest. This phenomenon is studied through performances and recordings of Weber's Der Freischütz Overture. Terminology for different perspectives on temporal shaping is proposed. The historical impact of tempo modification is explored through a comparative audio analysis of three central recordings. The same analytical procedures are then subsequently applied to the author's two recordings, and a cross-comparison is carried out of all five recordings. The thesis further discusses the use of reduction as a method for a conductor's score analysis. Through this multi-layered analysis, the thesis suggests that tempo modification is a stylistically and historically contingent phenomenon, the application of which is indeed dependent on structural elements in the score, but most of all dependent on compositional style and performance practice.

Among the alternatives to conventional Indium Tin Oxide (ITO) used in making transparent conducting electrodes, the random metal nanowire (NW) networks are considered to be superior offering performance at par with ITO. The performance is measured in terms of sheet resistance and optical transmittance. However, as the electrical properties of such random networks are achieved thanks to a percolation network, a minimum size of the electrodes is needed so it actually exceeds the representative volume element (RVE) of the material and the macroscopic electrical properties are achieved. There is not much information about the compatibility of this minimum RVE size with the resolution actually needed in electronic devices. Furthermore, the efficiency of NWs in terms of electrical conduction is overlooked. In this work, we address the above industrially relevant questions - 1) The minimum size of electrodes that can be made based on the dimensions of NWs and the material coverage. For this, we propose a morphology based classification in defining the RVE size and we also compare the same with that is based on macroscopic electrical properties stabilization. 2) The amount of NWs that do not participate in electrical conduction, hence of no practical use. The results presented in this thesis are a design guide to experimentalists to design transparent electrodes with more optimal usage of the material.

The purpose of this study was to analyze the characteristics of teacher directed modeling evidenced in the practices of three experienced high school choral directors. Research questions were: 1. What modeling activities were exhibited in each teacher's rehearsals? 2. When viewing a 45-minute composite tape of each teacher's instructional activities representative of all rehearsals, what instructional behaviors did each choral director recognize and identify as modeling? 3. What instructional episodes on the composite tape not identified by the teachers contained elements of modeling? 4. What other episodes from the remainder of each choral director's rehearsal practice contributed to an understanding of modeling? Videotapes of three high school choral directors were recorded over the course of one semester. Excerpts from rehearsals were combined to form a 45-minute composite tape of each choral director. A text transcription was made of the composite tape. Participant directors viewed their tape and identified instructional episodes that they recognized as examples of modeling. Identifications were analyzed, and descriptive categories of modeling behaviors were established. Modeling was found to be a teacher generated or delegated act of demonstration. Demonstrations were musical or non-musical and belonging to either of three distinct categories: audible, visible, or process modeling. Subdivisions of each category were found further describing modeling in the high school choral rehearsal. In addition, types of modeling were noted in increasing cognitive complexity required on the part of students beginning with simple imitation and concluding with models as tools for musical problem solving. Research is recommended on a larger sample of participants, including junior high/middle school directors to confirm categories and levels and to develop an observation tool based on results for describing, assessing, and modifying instructional techniques of practicing and pre-service music educators.