Dissertations / Theses on the topic 'Performance preparation'
To see the other types of publications on this topic, follow the link: Performance preparation.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Performance preparation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Brehm, Christoph Peter. "Mixture preparation and engine performance." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393869.
Full text
2
Aran, Bengi. "Preparation Of High Performance Acrylonitrile Copolymers." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611334/index.pdf.
Full textAbstract:
Acrylonitrile based engineering random copolymers were prepared via one step emulsion polymerization using ammonium persulfate (initiator), 1-dodecanthiol (chain transfer agent) and DOWFAX 8390 (surfactant) in the presence of water at approximately 65 0C. Three copolymer compositions were studied for novel polyacrylonitrile, (PAN)-polyhydroxyethyl acrylate (PHEA), PAN-polybutyl acrylate (PBA), novel PAN-polyt-butyl acrylate (PtBA), PAN-polyethyl acrylate (PEA) and PAN-polymethyl acrylate (PMA) with acrylate content varying from 8, 12 and 16 molar percent. Infrared spectroscopy, proton and carbon NMR were successfully utilized to confirm the chemical structure of copolymers. In order to determine the comonomer compositions in the copolymer structure, proton nuclear magnetic resonance, 1H NMR studies were carried out. Thermal (TGA, DSC) and mechanical properties of homo and copolymers were also investigated. Intrinsic viscosity (IV) measurements in dimethyl formamide (DMF) solution revealed that the molecular weight of the copolymers were quite enough to form ductile films.
In this study, hydrogels and their copolymers of acrylonitrile (PAN-PHEA) were also studied. Some properties of the free standing copolymer films such asswelling behaviors and densities were evaluated. It was also demonstrated that the nanocomposites of these copolymers could be utilized in filtration technology. Hence, novel PAN(88)-co-PMA(12) and polyaniline (PANI) nanocomposites were prepared at various PANI loadings to remove toxic chromium(VI) solution from water. Chemical structure, swelling and fracture morphology of the nanocomposites membranes were studied. It was observed that PANI had a great impact on the chromium removal. Permeate flux and rejection of chromium(VI) were demonstrated for various pHs and chromium(VI) concentrations. Finally, influences of comonomer composition on the thermal properties of the copolymers were investigated to input their structure property relation.
3
Li, Min. "Preparation of composite materials for high-performance supercapacitors." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I011.
Full textAbstract:
Les supercondensateurs, en tant que dispositifs de stockage d'énergie, ont attiré une grande attention dans notre vie quotidienne pour combler l'écart entre les batteries et les condensateurs. Par conséquent, la préparation d'électrodes en matériaux composites à hautes performances pour les supercondensateurs joue un rôle vital dans leurs futurs développements technologiques. Dans ce contexte, les hydroxydes doubles lamellaires (HDL) et Ni(OH)2 ont été reconnus comme des électrodes prometteuses pour les supercondensateurs en raison de leurs réactions redox rapides et de leur comportement de type batterie.Le chapitre 1 donne un bref aperçu historique ainsi que les principes et le mécanisme de stockage d'énergie, les matériaux d'électrode des supercondensateurs, et les méthodes de caractérisation correspondantes.Le chapitre 2, après un bref rappel sur la synthèse et l’utilisation de matériaux à base d’HDL comme électrodes de supercondensateurs, on décrit la préparation d’HDL à base de Ni comme électrodes pour les supercondensateurs. Premièrement, des HDLs à base de NiFe sur mousse de Ni (NF) recouverte d'oxyde de graphène réduit (LDF NiFe/rGO/NF) ont été préparées par une méthode de dépôt électrochimique. L’électrode NiFe HDL/rGO/NF présente une capacité spécifique de 585 C g-1 à une densité de courant de 5 A g-1. Dans la deuxième partie de ce chapitre, nous décrivons la synthèse hydrothermale d’HDLs à base de NiAl enrobées sur des sphères de carbone (CS) supportées par des électrodes en mousse de Ni (NiAl DHL@CS/NF). La performance des matériaux préparés en tant qu'électrodes sans liant dans des supercondensateurs a été évaluée. Le matériau d'électrode NiAl DHL@CS/NF présente une capacité surfacique de 1042 mC cm-2 à 1 mA cm-2, beaucoup plus élevée comparée aux valeurs de capacités surfaciques de NiFe HDL@CS/NF (705.8 mC cm-2) et de NiCr LDHs@CS/NF (814.9 mC cm-2) à 1 mA cm-2. Enfin, un matériau composite à base de NiMnCr sur un substrat de mousse de nickel recouvert de sphères de carbone (NiMnCr HDL@CS/NF) a été préparée en utilisant un processus hydrothermal en deux étapes. Le nanocomposite ainsi obtenu a été investigué comme électrode dans un supercondensateur et présente une capacité spécifique de 569 C g-1 à 3 A g-1 avec une bonne stabilité. De plus, un supercondensateur hybride a été fabriqué en utilisant NiMnCr HDL@CS/NF comme électrode positive et FeOOH déposé sur NF (FeOOH/NF) comme électrode négative. Le dispositif présente une densité d'énergie de 48 Wh kg-1 à une densité de puissance de 402.7 W kg-1. Dans le chapitre 3, des électrodes sans liant Ni(OH)2@CuO sur une mousse de cuivre ont été synthétisées par un processus en deux étapes à température ambiante. Nous avons étudié l’effet du temps de dépôt (30, 50, 90, 150 et 200 s) sur le comportement électrochimique des électrodes obtenues. Parmi tous les échantillons, Ni(OH)2@CuO@Cu-150 présente la plus grande capacité surfacique de 7063 mC cm-2 à 20 mA cm-2, et a donc été choisi comme électrode positive dans un supercondensateur hybride. En utilisant de l'oxyde de graphène réduit dopé à l’azote sur de la mousse de nickel (N-rGO/NF) comme électrode négative, un supercondensateur hybride a été assemblé. Il présente une bonne flexibilité, une stabilité cyclique et une densité d'énergie surfacique élevée de 130.4 μWh cm-2 à une densité de puissance de 1.6 mW cm-2.Une conclusion générale rappelle les principaux résultats obtenus dans ce travail de thèse sur l'application de composites d'hydroxydes doubles lamellaires à base de Ni en tant qu’électrodes dans des dispositifs de stockage d'énergie, et présente quelques perspectives envisageables à la lumière de ces travaux (chapitre 4)Supercapacitors, as energy storage devices, have drawn great attention in our daily life to bridge the gap between batteries and capacitors. Therefore, the preparation of high-performance material electrodes for supercapacitors plays a vital role in the future technological developments. In this context, layered double hydroxides (LDHs) and Ni(OH)2 have been recognized as promising electrodes for supercapacitors, owing to their fast redox reaction and battery-type behavior.The Chapter 1 of my PhD work gives a brief historic overview, principles and mechanism of energy storage, electrode materials of supercapacitors and the corresponding characterization methods. In Chapter 2, after a brief introduction on LDHs and their investigation as electrode materials in supercapacitors, we summarize our results obtained on Ni-based LDHs as electrodes for supercapacitors. Firstly, NiFe LDHs on Ni foam (NF) coated with reduced graphene oxide (NiFe LDHs/rGO/NF) was prepared by electrochemical deposition method. NiFe LDHs/rGO/NF achieved enhanced specific capacity (585 C g-1 at a current density of 5 A g-1). Additionally, a flexible asymmetric supercapacitor was assembled using NiFe LDHs/rGO/NF as the cathode and mesoporous carbon (MC) coated on NF as the anode. The supercapacitor exhibited an energy density of 17.71 Wh kg-1 at a power density of 348.49 W kg-1. Secondly, NiAl LDHs coated on carbon spheres (CS) supported by Ni foam (NiAl LDHs@CS/NF) electrodes were synthesized by a facile hydrothermal method. The performance of the prepared materials as binder-free electrodes in supercapacitors was assessed. The NiAl LDHs@CS/NF electrode achieved the largest areal capacity (1042 mC cm-2), as compared to the areal capacity values attained by NiFe LDHs@CS/NF (705.8 mC cm-2) and NiCr LDHs@CS/NF (814.9 mC cm-2) at 1 mA cm-2. Therefore, a hybrid supercapacitor device comprising NiAl LDHs@CS/NF as the positive electrode and N-doped reduced graphene/NF as the negative electrode was assembled, which attained an energy density of 43 μWh cm−2 at a power density of 0.805 mW cm−2. The hybrid supercapacitor was successfully applied to operate a windmill device continuously for 32 s. Finally, NiMnCr LDHs-carbon spheres modified Ni foam (NiMnCr LDHs@CS/NF) nanocomposite was prepared using a two-step hydrothermal process and exhibited a high specific capacity of 569 C g-1 at 3 A g-1 with good reversibility and stability. Furthermore, a hybrid supercapacitor was fabricated using NiMnCr LDHs@CS/NF as the positive electrode and FeOOH coated on NF (FeOOH/NF) as the negative electrode. The energy storage device reached an energy density of 48 Wh kg-1 at a power density of 402.7 W kg-1. In Chapter 3, Ni(OH)2@CuO@Cu foam binder-free electrodes were fabricated by a two-step process at room temperature with various deposition times (30, 50, 90, 150 and 200s). Among all the samples, Ni(OH)2@CuO@Cu-150 exhibited the largest areal capacity of 7063 mC cm-2 at 20 mA cm-2, and was therefore chosen as the positive electrode in a hybrid supercapacitor. Using N-doped reduced graphene oxide on nickel foam (N-rGO/NF) as the negative electrode, a hybrid supercapacitor was assembled. It displayed good flexibility, cycling stability and high areal energy density of 130.4 μWh cm−2 at a power density of 1.6 mW cm−2.In conclusion, all the results obtained in this thesis imply the promising potential application of Ni-based hydroxide composites as energy storage devices and provide valuable highlights to the exploration of new composite materials for supercapacitor electrodes in future works (Chapter 4)
4
Lee, Sheri Renee. "Four Twelve-Tone Violin Compositions: Performance Practice and Preparation." Cincinnati, Ohio : University of Cincinnati, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1242516300.
Full textAbstract:
Thesis (Dr. of Musical Arts)--University of Cincinnati, 2009.Advisor: Steven Cahn. Title from electronic thesis title page (viewed Aug. 11, 2009). Includes abstract. Keywords: twelve-tone; violin. Includes bibliographical references.
5
Gardner, David B. "Herbert Howells' Requiem: A guide to preparation and performance." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280285.
Full textAbstract:
Although composed in the 1930s, Herbert Howells' Requiem for unaccompanied voices was not performed or published until the early 1980s. The long period between its composition and publication has left many questions about its origins unanswered. The document attempts to clarify the confusing genesis of Howell's Requiem, and suggests that the motivation behind its composition was the commemoration of those who died in World War I, and not, as has been previously supposed, the death of Howells' son Michael in 1935. The development of Howells' own compositional style is traced through musical influences, and the difficult circumstances of Howells' formative years. Three stylistic influences are discussed: the generation of English composers immediately preceding Howells, the generation of English composers from the sixteenth century, and the English countryside and the tunes of its people. The last two chapters deal with the Requiem in detail, providing conductors with textual and musical analyses and with suggestions for score preparation, rehearsal techniques, and performance logistics.
6
Werthner-Bales, Penny C. "Investigating the preparation and perspectives of eight high performance athletes." Thesis, University of Ottawa (Canada), 1998. http://hdl.handle.net/10393/21284.
Full text
7
Macgregor, Lewis James. "Neuromuscular markers of high performance sport preparation : muscle contractile mechanics." Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/24445.
Full textAbstract:
Assessments of skeletal muscle functional capacity or bilateral muscular asymmetry often necessitate maximal contractile effort, which exacerbates muscle fatigue or injury. Tensiomyography (TMG) has been investigated in laboratory settings, as a means to assess muscle contractile function following fatigue; however observations have not been contextualised by concurrent physiological measures. TMG has more sparingly been applied in the field, with elite athletes. The aim of this thesis was to examine acute alterations and underlying variations in muscle contractile mechanics, through the application of TMG, contextualised with established physiological measures; and to apply TMG within high performance sports programmes. TMG successfully detected fatigue, evident from reduced strength, by displaying impaired muscle displacement, accompanied by elevated resting muscle tension. Greater asymmetry was detected in individuals with asymmetric strength; however, symmetry was masked during more complex tasks. Increased day-to-day variability was detected among highly trained athletes compared to recreationally active individuals. Acute training adaptations were detected, in contractile mechanics, in individual muscles. TMG could be useful in establishing fatigue status of skeletal muscle without exacerbating the functional decrements of the muscle, whilst also providing useful screening information for detecting asymmetry which may not be apparent during functional actions.
8
Werthner, Penny C. "Investigating the preparation and perspectives of eight high performance athletes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0013/NQ38800.pdf.
Full text
9
Dirlam, Philip Thomas, and Philip Thomas Dirlam. "Preparation of Electroactive Materials for High Performance Lithium-Sulfur Batteries." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621564.
Full textAbstract:
This dissertation is comprised of five chapters detailing advances in the synthesis and preparation of polymers and materials and the application of these materials in lithium-sulfur batteries for next-generation energy storage technology. The research described herein discusses progress towards overcoming three critical challenges presented for optimizing Li-S battery performance, specifically, addressing the highly electrically insulating nature of elemental sulfur, extending the cycling lifetime of Li-S batteries, and enhancing the charge discharge rate capability of Li-S cathodes. The first chapter is a review highlighting the use of polymers in conventional lithium-sulfur battery cathodes. Li-S battery technology presents a grand opportunity to realize an electrochemical energy storage system with high enough capacity and energy density capable of addressing the needs presented by electrical vehicles and base load storage. Polymers are ubiquitous throughout conventional Li-S batteries and their use has been critical in overcoming the challenges presented for optimizing Li-S cathode performance towards practical implementation. The high electrical resistivity of elemental sulfur requires the incorporation of conductive additives in order to formulate it into a functional cathode. A polymer binder must be utilized to integrate the elemental sulfur as the active material with the conductive additives into an electrically conductive composite affixed to a current collector. The electrochemical action of the Li-S battery results in the electroactive sulfur species converting between high and low order lithium polysulfides as the battery is discharged and charged. These lithium polysulfides become soluble at various stages throughout this cycling process that lead to a host of complications including the loss of electroactive material and slow rate capabilities. The use of polymer coatings applied to both the electroactive material and the cathode as a whole have been successful in mitigating the dissolution of lithium polysulfides by confining the redox reactions to the cathode. Elemental sulfur is largely intractable in conventional solvents and suffers from poor chemical compatibility limiting synthetic modification. By incorporating S-S bonds into copolymeric materials the electrochemical reactivity of elemental sulfur can be maintained and allow these polymers to function as the electroactive cathode materials while enabling improved processability and properties via the comonomeric inclusions. The use of inverse vulcanization, which is the direct copolymerization of elemental sulfur, is highlighted as a facile method to prepare polymeric materials with a high content of S-S bonds for use as active cathode materials. The second chapter focuses on the synthesis and polymerization of a novel bifunctional monomer containing both a styrenic group to access free radical polymerization and a propylenedioxythiophene (ProDOT) to install conductive polymer pathways upon an orthogonal oxidative polymerization. The styrenic ProDOT monomer (ProDOT-Sty) was successfully applied to a two-step sequential polymerization where the styrenic group was first leveraged in a controlled radical polymerization (CRP) to afford well defined linear homo- and block polymer precursors with pendant electropolymerizable ProDOT moieties. Subsequent treatment of the these linear polymer precursors with an oxidant in solution enabled the oxidative polymerization of the pendant ProDOT groups to install conductive polythiophene inclusions. Although the synthesis and CRP of ProDOT-Sty was novel, the key advance in this work was successful demonstration that sequential radical and oxidative polymerizations could be carried out to install conductive polymer pathways through an otherwise nonconductive polymer matrix. The third chapter expands upon the use of ProDOT-Sty to install conductive polymer pathways through a sulfur copolymer matrix. The highly electrically insulating nature of elemental sulfur precludes its direct use as a cathode in Li-S batteries and thus the use of ProDOT-Sty in the preparation of a high sulfur content copolymer with conductive inclusions was targeted to improve electrical properties. Inverse vulcanization of elemental sulfur with ProDOT-Sty and a minimal amount of 1,3-diisopropenylbenzene (DIB) was first completed to afford a sulfur rich copolymer with electropolymerizable side chains. Subsequently, the improved processability of the sulfur copolymer was exploited to prepare thin polymer films on electrode surfaces. The poly(ProDOT-Sty-𝑐𝑜-DIB-𝑐𝑜-sulfur) (ProDIBS) films were then subjected to oxidizing conditions via an electrochemical cell to invoke electropolymerization of the ProDOT inclusions and install conductive poly(ProDOT) pathways. Evaluation of the electrical properties with electrochemical impedance spectroscopy (EIS) revealed that the charge transfer resistance was reduced from 148 kΩ to 0.4 kΩ upon installation of the conductive poly(ProDOT) corresponding to an improvement in charge conductance of more than 95%. This also represented a key advance in expanding the scope of the inverse vulcanization methodology as the first example of utilizing a comonomer with a functional side chain. The fourth chapter focuses on expanding the scope of the inverse vulcanization polymerization methodology to include aryl alkyne based comonomers and the application of new these new sulfur copolymers as active cathode materials in Li-S batteries. The early work on developing inverse vulcanization relied heavily on the use of DIB as one of the few comonomers amenable to bulk copolymerization with elemental sulfur. One of the principal limitations in comonomer selection for inverse vulcanization is the solubility of the comonomer in molten sulfur. Generally it has been observed that aromatic compounds with minimal polarity are miscible and thus common classes of comonomers such as acrylates and methacrylates are immiscible and preclude their compatibility with inverse vulcanization. It was found that aryl alkynes are a unique class of compounds that are both miscible with molten sulfur and provide reactivity with sulfur centered radicals through the unsaturated carbon-carbon triple bonds. Additionally, it was found that internal alkynes were best suited for inverse vulcanization to preclude abstraction of the somewhat acidic hydrogen from terminal alkynes. 1,4-Diphenylbutadiyne (DiPhDY) was selected as a prototypical comonomer of this class of compounds for preparing high sulfur content copolymers via inverse vulcanization. Poly(sulfur-𝑐𝑜-DiPhDY) was prepared with various compositions of S:DiPhDY and these copolymers were formulated into cathodes for electrochemical testing in Li-S batteries. The poly(S-𝑐𝑜-DiPhDY) based cathodes exhibited the best performance reported at the time for a polymeric cathode material with the figure of merit of the first inverse vulcanizate to enable a cycle lifetime of up to 1000 cycles. The fifth chapter details the preparation of composite materials composed of a sulfur or copolymeric sulfur matrix with molybdenum disulfide (MoS₂) inclusions and the use of these materials for Li-S cathodes with rapid charge/discharge rate capabilities. The higher order lithium polysulfide redox products (e.g., Li₂S₈ Li₂S₆) generated during Li-S cycling are soluble in the electrolyte solution of the battery. The rate capability of the Li-S battery is thus fundamentally limited by mass transfer as these electroactive species must diffuse back to the cathode surface in order to undergo further reduction (discharge) or oxidation (charge). In order to limit the effective diffusion length of the soluble lithium polysulfides and therefore mitigate the diffusion limited rate, composite materials with fillers capable of binding the lithium sulfides were prepared. MoS₂ was selected as the filler as simulations had indicated lithium polysulfide had a strong binding interaction with the surface of MoS₂. Furthermore, it was demonstrated for the first time that metal chalcogenides such as MoS₂ readily disperse in molten sulfur which enabled the facile preparation of the composite materials in situ. The composites were prepared by first dispersing MoS₂ in liquid sulfur or a solution of liquid sulfur and DIB below the floor temperature of S₈ (i.e.<160 °C). The dispersions were then heated above the floor temperature of S₈ to induce ring opening polymerization of the sulfur phase and afford the composites. The composites were found to be potent active cathode materials in Li-S batteries enabling extended cycle lifetimes of up to 1000 cycles with excellent capacity retention. Furthermore, the composite materials were successful in enhancing the rate capability of the Li-S cathodes where reversible capacity of >500 mAh/g was achieved at the rapid rate of 5C (i.e. a 12 min. charge or discharge time).
10
Michalak, Filip. "Piano Competitions : Preparation and Purpose." Thesis, Kungl. Musikhögskolan, Institutionen för klassisk musik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-2854.
Full text
11
McCarty, Emily C. "Preparatory and Performance Self-Efficacy in Athletes." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1438120542.
Full text
12
Cheng, Eunise Ansherina. "Performance preparation of Paul Hindemith's three Sonatas for Viola and Piano: Practice strategies to provide musical insight and technical control." Thesis, Griffith University, 2019. http://hdl.handle.net/10072/388974.
Full textAbstract:
This thesis aims to provide materials useful for the preparation and performance of the Hindemith’s three Viola Sonata with Piano: Sonata Op. 11 No. 4 (1919), Sonata Op. 25 No. 4 (1922), Sonata (1939). It serves directly as a practical source for violists and teachers who are learning the sonatas to consult students.
The project considers different resources available including relevant historical contextual information about Hindemith’s life, his compositional style and history surrounding the three viola sonatas and piano. It recommends different available recordings of the sonatas for insight and provides suggestions to additional complementary resources for further reading.
Much of this project however focuses on the practice processes I employed to enhance my performance of the sonatas. These include providing guidance on how to formulate musical ideas specific to the piece, various practice strategies for challenging aspects and specifically investigate different processes of technique, such as sound production, intonation, shifting and bow distribution. Assisted by the opinions and explorations of professional violists, this project will document and reflect various practice strategies I have employed in preparing the Viola Sonatas with piano.
Every musician has their own personal process to learn a piece, so it is not my intention to propose my method as the sole or best method of learning the sonatas. Rather, it serves as a guide to provide performers with further options on learning the sonatas themselves as efficiently as possible and enlisting as many available resources relevant to the sonatas to encourage players to learn the works themselves. The practice principles established within this project assisting with technique, interpretation are transferrable and can be directly applicable to the twentieth-century works or other contemporary works.Thesis (Masters)
Master of Music Research (MMusRes)
Queensland Conservatorium
Arts, Education and Law
Full Text
13
Rand, Catherine A. "Christopher Rouse's Wolf Rounds: Compositional Insight and World Premiere Performance Preparation." Scholarly Repository, 2007. http://scholarlyrepository.miami.edu/oa_dissertations/53.
Full textAbstract:
The purpose of this essay is to explore the commissioning process of a wind ensemble piece by notable composer Christopher Rouse, and its significance to the wind ensemble repertoire. This essay will use the University of Miami Frost Wind Ensemble and Christopher Rouse's Wolf Rounds as the primary example. This discussion will provide an extensive background review of Christopher Rouse's early musical experience and life's accomplishments. It will focus on his creative process and document the performance preparation of Wolf Rounds as experienced by the Frost Wind Ensemble, conducted by Professor Gary D. Green. The final part of this essay will investigate the compositional insight of Wolf Rounds as well as the inspiration and motivation of Rouse to write for the wind ensemble genre. While Rouse has written for many different types of ensembles, this will be his first published addition to the wind repertoire. Wolf Rounds was chosen as the primary composition because of its significance to the composer as his first composition for winds and percussion.
14
Lou, Ziman, Yunfei Peng, and Teng Wang. "Customer Perceived Value in Language Test Preparation Service : Performance Measurement on Four Dominant Language Test Preparation Institutes in China." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227339.
Full textAbstract:
This thesis aims at studying customer perceived value in language test training industry through an empirical research on four dominate IELTS training institutes in China. Customer questionnaires are used to get customers’ preferences about language test training service, as well as their perceived value of each institute. Based on that, a measurement of each institute’s performance according to the customer preferences is conducted. After analysis, the strength and weakness of each institute is clearly showed, followed by relative explanations and suggestions for their weaknesses.
15
Lu, Huanghai. "Preparation and performance of BSCF-based Mixed Ionic-Electronic Conducting (MIEC) ceramics." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/preparation-and-performance-of-bscfbased-mixed-ionicelectronic-conducting-miec-ceramics(bef05576-e133-4d72-825b-27d8982a2a8d).html.
Full textAbstract:
Preparation and performance of the perovskite-type barium strontium cobalt iron oxide (Ba_0.5 Sr_0.5 Co_0.8 Fe_0.2 O_(3-δ), BSCF) and its doped compositions were studied in this dissertation. Three transition metals (copper, nickel and niobium) were substituted into the parent BSCF at various ratios to create the formula Ba_0.5 Sr_0.5 (Co_0.8 Fe_0.2)_(1-x) M_x O_(3-δ) (0.02≤x≤0.30; M=Cu,Ni or Nb). Two synthetic methods (solid-state reaction and wet chemical co-precipitation) were developed for the preparation of starting powders. In the previous reports [1, 2], BSCF ceramics suffered from insufficient densification and severe cracking; these problems were resolved in this study by optimising the ceramic processing conditions. The phase transition sequences from starting powders to single-phase cubic perovskite were studied by SEM, XRD, TGA, EDS and Raman spectroscopy. The powders prepared by solid-state method were found to require higher calcination temperature to form pure perovskite phase, and an extra intermediate structure (Ba,Sr)Fe_2 O_4 was detected in the reaction sequence. The materials performance was examined from five aspects: thermal stability, chemical stability, oxygen permeability, electronic conductivity and mechanical performance. The secondary phases of thermal/chemical degradation were investigated, and a needle-like intragranular precipitate was originally discovered in this work. It was discovered that the niobium substitution could significantly improve BSCF’s thermal stability and chemical stability. The oxygen permeability and mechanical performance were also improved by niobium when the substitution ratios are small (< 10%). Although the electronic conductivity was lowered by niobium substitution as a trade-off, it does not become a drawback to restrict the materials’ potential applications as mixed ionic-electronic conductors (MIEC).Furthermore, the material system’s “composition - lattice structure - performance” relationships were systematically investigated in this work; the oxygen deficiency value (δ) and the average bond energy (ABE) were found to have strong correlations with the materials performance.
16
Walton, Cassidy. "An Investigation of the Relationship Between Motivation, Test Preparation and Test Performance." TopSCHOLAR®, 2002. http://digitalcommons.wku.edu/theses/571.
Full textAbstract:
The relationship between motivation, test preparation, and test performance was investigated using two samples, lire fighter applicants and college students. Motivation and test preparation were measured by Arvey and Stickland's (1991) Test Attitude Survey; test performance consisted of selection test scores or class examinations. The results indicated that the relationship between motivation, test preparation, and test performance varied depending on the sample (i.e., fire fighter applicants or college students) and the context (i.e., written or Physical Ability Test, class exam, or final examination). The results for fire fighters indicated that motivation was related to written test performance but not to performance on the Physical Ability Test, and that test preparation was related to performance on the Physical Ability Test but not on the written test. The results for the students revealed a significant, negative relationship between test preparation and test performance, suggesting that "cramming" for the test was not related to improved test performance.
17
Raber, Rebecca Lynn. "Conducting the Coded Message Songs of Slavery: Context, Connotation, and Performance Preparation." Diss., North Dakota State University, 2018. https://hdl.handle.net/10365/28976.
Full textAbstract:
The coded message songs of slavery are a mysterious and fascinating entity. Within the lyrics of these seemingly innocuous plantation songs are coded messages for escape, messages that provided secret information to enslaved workers on Antebellum plantations. Over the course of more than 250 years of slavery on American soil, countless enslaved Africans found freedom through the use of coded message songs and the Underground Railroad. What are these songs? Which lyrics provided this secret information? How can a study of this music provide a better musical experience for conductors, singers, and listeners? This disquisition offers answers to these important questions, as well as a presentation of this body of repertoire from the choral conductor?s perspective. First, I provide a brief historical context for the music of slavery. I analyze and interpret important historical collections of spirituals and examine them through the lens of their text. Period accounts (from newly freed slaves and by song collectors) as well as information from modern conductors and scholars provide insight into and support for my method. A discussion of textual interpretation and musical representation follows, including a valuable list of common themes used in coded message songs. In the main body of the document, I present nine spirituals that contain coded message. I focus on the lyrics of the coded songs, introducing the connotations of the messages within the music. I also offer insight to choral conductors considering this repertoire and some interpretive choices that may be made when performing this music. Finally, this study contributes appendices with concrete pedagogical resources to assist conductors in their teaching and presentation of coded message songs to their singers. Successful choral conductors are dynamic storytellers. As a conductor preparing, rehearsing, and performing this choral music, it is critical to both communicate the context and history of coded message songs during the learning process, and also make appropriate stylistic choices in the music. Revealing the historical context and rich textual interpretation of this body of repertoire allows conductors to tell this story more effectively through their informed pedagogy, ultimately enriching and inspiring both singers and listeners.
18
Burdette, Joy L. "Thomas Pasatieri's Letter to Warsaw: An Examination of Style for Performance Preparation." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1377872551.
Full text
19
Williams, Angharad. "Electrophysiological indices of preparation and behavioural performance measures for episodic memory retrieval." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/90376/.
Full textAbstract:
The experiments in this thesis were designed to understand how and when preparation for episodic retrieval occurs, and what functions effective preparation enables. It has been proposed that in order to engage in episodic memory retrieval one must be in a certain cognitive state, known as retrieval mode, which ensures that stimulus events are treated as episodic memory cues. The experiments described below identify boundary conditions for when correlates of retrieval mode can be observed, and contribute new information about how retrieval mode contributes to episodic retrieval. This was accomplished via analysis of behavioural and Event-Related Potential (ERP) data.
20
George, Anna Ray Bayless. "Impact of Texas High School Science Teacher Credentials on Student Performance in High School Science." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc149592/.
Full textAbstract:
A study was conducted to determine the relationship between the credentials held by science teachers who taught at a school that administered the Science Texas Assessment on Knowledge and Skills (Science TAKS), the state standardized exam in science, at grade 11 and student performance on a state standardized exam in science administered in grade 11. Years of teaching experience, teacher certification type(s), highest degree level held, teacher and school demographic information, and the percentage of students who met the passing standard on the Science TAKS were obtained through a public records request to the Texas Education Agency (TEA) and the State Board for Educator Certification (SBEC). Analysis was performed through the use of canonical correlation analysis and multiple linear regression analysis. The results of the multiple linear regression analysis indicate that a larger percentage of students met the passing standard on the Science TAKS state attended schools in which a large portion of the high school science teachers held post baccalaureate degrees, elementary and physical science certifications, and had 11-20 years of teaching experience.
21
Liu, G. R., S. C. Zhang, X. X. Lu, and X. Wei. "Preparation of Nanostructured Li2MnO3 Cathode Materials by Single-Step Hydrothermal Method." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35190.
Full textAbstract:
Nanosized (10~50 nm) cathode material Li2MnO3 was prepared for with MnSO4·H2O，KMnO4 and Li-
OH aqueous solution as the precursor via single-step hydrothermal reaction by controlling the reaction
time, proportion of processor, and the reagent concentration. The prepared materials were well crystallized
and exhibited a monoclinic Li2MnO3 structure with a space group of C2/m phase. The electrochemical performance
of the material was tested at current density of 60 mAg-1 (1/4 C) between 4.3V and 2.0 V at room
temperature, showing good electrochemical properties with the initial discharge capacity of 243 mAh·g-1,
because it was more exposed to the electrolyte due to its nanostructure.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35190
22
Till, Theresa L. Riegle Rodney P. "The relationship between management performance and age and educational preparation of nursing students." Normal, Ill. Illinois State University, 2002. http://wwwlib.umi.com/cr/ilstu/fullcit?p3064525.
Full textAbstract:
Thesis (Ed. D.)--Illinois State University, 2002.Title from title page screen, viewed February 16, 2006. Dissertation Committee: Rodney P. Riegle (chair), Kenneth H. Strand, Donna A. Redding, Amelia D. Adkins. Includes bibliographical references (leaves 116-123) and abstract. Also available in print.
23
Yarahmadi, Sina. "Preparation and performance of nanostructured iron oxide thin films for solar hydrogen generation." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8131.
Full textAbstract:
Nowadays, energy and its resources are of prime importance at the global level. During the last few decades there have been several driving forces for the investigation of new sources of energy. Hydrogen has long been identified as one of the most promising carriers of energy. Photoelectrochemical (PEC) water splitting is one of the most promising means of producing hydrogen through a renewable source. Hematite (α-Fe2O3) is a strong candidate material as photoelectrode for PEC water splitting as it fulfils most of the selection criteria of a suitable photocatalyst material for hydrogen generation such as bandgap, chemical and photelectrochemical stability, and importantly ease of fabrication. This work has explored different preparation techniques for undoped and Si-doped iron oxide thin films using microwave-assisted and conventional preparation methods. Two distinct strategies towards improving PEC performance of hematite photoelectrodes were examined: retaining a finer nanostructure and enhancing the photocatalytic behaviour through doping. By depositing thin films using atmospheric pressure chemical vapour deposition (APCVD) and aerosol-assisted CVD (AACVD) at high temperature, it was shown that a combination of different factors (such as silicon incorporation into the hematite structure and formation of lattice defects, along with a nanostructure of small agglomerate/cluster enhancing hole transportation to the surface) were the contributing factors in improving the PEC performance in hematite films. The role of the Si-containing precursors and their consecutive effect on nanostructure of the hematite films were investigated. Further work is needed to study the decomposition pattern of precursors and consequent effects of Si additives as well as co-dopants on fundamental physical and electrical properties of hematite electrodes. In addition, the feasibility of using microwave annealing for the fabrication of iron oxide thin films prepared by electrodeposition at low temperature was also investigated. Hematite films showed improved PEC performance when microwave assisted annealing was used. Microwave heating decreased the annealing temperature by ~40% while the PEC performance was increased by two-fold. The improved performance is attributed to the lower processing temperatures and rapidity of the microwave method that help to retain the nanostructure of the thin films whilst restricting the grain coalescence to a minimum. Around 60% of the energy can be saved using this low carbon foot-print approach compared to conventional annealing procedures for the lab-scale preparation of hematite films – a trait that will have significant implications for scale-up production. The lower processing temperature requirements of the microwave process can also open up the possibility of fabricating hematite thin films on conducting, flexible, plastic electronic substrates.
24
Lively, Treise. "Ethanol fuel cell electrocatalysis : novel catalyst preparation, characterization and performance towards ethanol electrooxidation." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602560.
Full text
25
Bouhjar, Feriel. "Preparation et performance d'une cellule photocatalytique à base d'hématite pour la génération d'hydrogène." Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/106345.
Full textAbstract:
El hidrógeno es un portador de energía que ya ha demostrado su capacidad para reemplazar el
petróleo como combustible. Sin embargo, los medios de producción actualmente en uso
siguen siendo altamente emisores de gases de efecto invernadero. La foto-electrólisis del agua
es un proceso que, a partir de la energía solar, separa los compuestos elementales del agua
como el hidrógeno y el oxígeno utilizando un semiconductor con propiedades físicas
adecuadas. La hematita (¿-Fe2O3) es un material prometedor para esta aplicación debido a su
estabilidad química y su capacidad para absorber una porción significativa de la luz (con una
banda prohibida entre 2.0 - 2.2 eV). A pesar de estas propiedades ventajosas, existen
limitaciones intrínsecas al uso de óxido de hierro para la descomposición fotoelectroquímica
del agua. La primera restricción es la posición de su banda de conducción que es menor que el
potencial de reducción de agua. Esta limitación se puede superar mediante la adición en serie
de un segundo material, en tándem, que absorberá una parte complementaria del espectro
solar y llevar a los electrones a un nivel de energía más alto que el potencial para la liberación
de hidrógeno. El segundo obstáculo proviene del desacuerdo entre la corta longitud de
difusión de los portadores de carga y la profundidad de penetración larga de la luz. Por lo
tanto, es necesario controlar la morfología de los electrodos de hematita en una escala de
tamaño similar a la longitud de transporte del orificio.
En esta tesis, se introduce un nuevo concepto para mejorar el rendimiento fotoelectroquímico
de la hematita. Usando el método hidrotermal depositamos capas delgadas de hematita dopada
con Cr en sustratos de vidrio conductivo. También se ha preparado por medios
electroquímicos una heterounión del tipo p-CuSCN/n-Fe2O3 depositando secuencialmente una
capa de ¿-Fe2O3 y una película de CuSCNsobre sustratos de FTO (SnO2: F).Finalmente, se ha
preparado células solares de perovskitas y óxido de hierro. Para ello se depositó una capa
delgada, densa y uniformede óxido de hierro (¿-Fe2O3) como capa de transporte de electrones
(ETL) en lugar de dióxido de titanio (TiO2) que se utiliza convencionalmente en las células
fotovoltaicas perovskitastipoCH3NH3PbI3 (SGP). Este último dispositivo mostró un aumento
en la fotocorriente del 20% y un IPCE30 veces mayor que la hematita simple, lo que sugiere
una mejor conversión de las longitudes de onda por encima de 500 nm.
Palabras clave:
Fotoelectroquímica, división de agua, producción de hidrógeno, evolución de oxígeno,
semiconductores de óxido de metal, hematita, óxido de hierro, nanoestructurasHydrogen is an energy carrier that has already demonstrated its ability to replace oil as a fuel. However, the means of production currently used remain highly emitting greenhouse gases. Photo-electrolysis of water is a process that uses solar energy to separate the elemental compounds of water such as hydrogen and oxygen using a semiconductor with adequate physical properties. Hematite (¿-Fe2O3) is a promising material for this application because of its chemical stability and ability to absorb a significant portion of light (with a band-gap between 2.0 - 2.2 eV). Despite these advantageous properties, there are intrinsic limitations to the use of iron oxide for the photoelectrochemical cracking of water. The first constraint is the position of its conduction band, which is lower than the water reduction potential. This constraint can be overcome by the addition in series of a second material, in tandem, which will absorb a complementary part of the solar spectrum and bring the electrons to a higher energy level than the potential of hydrogen release. The second obstacle comes from the disagreement between the short diffusion length of the charge carriers and the long light penetration depth. It is therefore necessary to control the morphology of the hematite electrodes on a scale of similar size to the transport length of the hole. In this thesis a new concept is introduced to improve the photoelectrochemical performances. Using the hydrothermal method we deposited thin layers of Cr-doped hematite on conductive glass substrates. We also electrochemically prepared a p-CuSCN / n-Fe2O3 heterojunction by sequentially depositing ¿-Fe2O3 and CuSCN films on FTO (SnO2: F) substrates. Finally, we have used uniform and dense thin layers of iron oxide (¿-Fe2O3) as an electron transport layer (ETL) in place of titanium dioxide (TiO2) conventionally used in photovoltaic cells based on perovskites CH3NH3PbI3 (PSC). This latter concept showed a 20% increase of the photocurrent and an IPCE 30 times greater than the simple hematite, suggesting better conversion of high wavelengths (> 500 nm). Keywords: Photoelectrochemistry, Water Splitting, Hydrogen Production, Oxygen Evolution, MetalOxide Semiconductors, Hematite, Iron Oxide, Nanostructures, Surface.
L'hidrogen és un proveïdor d'energia que ja ha demostrat la seva capacitat per reemplaçar el petroli com a combustible, però els mitjans de producció actuals continuen essent fortament emissors dels gasos responsables d'efecte hivernacle. La fotoelectròlisi de l'aigua és un procés que, a partir de l'energia solar, separa els compostos elementals d'aigua com l'hidrogen i l'oxigen utilitzant un semiconductor amb propietats físiques adequades. La hematita (¿-Fe2O3) és un material prometedor per a aquesta aplicació a causa de la seva estabilitat química i capacitat d'absorbir una porció significativa de la llum (amb un gap entre 2,0 i 2,2 eV). Malgrat aquestes propietats avantatjoses, hi ha limitacions intrínseques per a l'ús d'òxid de ferro per a la descomposició fotoelectroquímica de l'aigua. La primera restricció és la posició de la seva banda de conducció que és inferior al potencial de reducció d'aigua. Aquesta limitació es pot superar mitjançant l'addició en sèrie d'un segon material, en tàndem, que absorbirà una part complementària de l'espectre solar i portar els electrons a un nivell d'energia més alt que el potencial per a l'alliberament d'hidrogen. El segon obstacle prové del desacord entre la curta durada de la difusió dels portadors de càrrega i la llarga profunditat de penetració de la llum. Per tant, és necessari controlar la morfologia dels elèctrodes d'hematita en una escala de mida similar a la longitud del forat del transport. En aquesta tesi, es presenta un nou concepte per millorar el rendiment fotoelectroquímic. Mitjançant el mètode hidrotermal es van dipositar capes primes de hematita Cr-doped sobre substrats de vidre conductor. També s'han preparat electroquímicamentheterounions de tipus p-CuSCN/n-Fe2O3 dipositant seqüencialment una capa de ¿-Fe2O3 i altra de CuSCN sobre substrats FTO (SnO2: F).Finalment, s'han produït cél·lules solars de perovskitesi óxid de ferro. Per això es va depositaruna capa prima,densai uniforme d'òxid de ferro (¿-Fe2O3) com a capa de transport d'electrons (ETL) en lloc de diòxid de titani (TiO2) que s'utilitza convencionalment en les cèl·lules fotovoltaiques de perovskita híbrida del tipus CH3NH3PbI3 (SGP). Aquest últim dispositiu va mostrar un augment del fotocorrent del 20% i una IPCE30 vegades superior a la hematita simple, la qual cosa suggereix una millor conversió a longitud d'ones per sobre de 500 nm. Paraules clau:Fotoelectroquímica, divisió d'aigua, producció d'hidrogen, evolució d'oxigen, semiconductors d'òxids metàl·lics, hematita, òxid de ferro, nanoestructures.
Bouhjar, F. (2018). Preparation et performance d'une cellule photocatalytique à base d'hématite pour la génération d'hydrogène [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/106345
TESIS
26
Chirinos, Maruri Ada Elida. "Influence of preparation techniques on the Fischer-Tropsch performance of supported cobalt catalysts." Doctoral thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/5365.
Full textAbstract:
Includes bibliographical references.Cobalt based catalysts are generally used for the FT synthesis due to their high activity and selectivity for linear hydrocarbons, low activity for the water gas shift reaction and lower price compared to noble metals [22]. There can, however, be a large effective loss of active metal due to strong metal-support interaction forming complexes that are not reduced at temperatures below 400°C.
27
Barkhuizen, David Andrew. "Preparation and water-gas shift performance of zinc oxide supported dispersed gold catalysts." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/22065.
Full textAbstract:
Includes bibliographical references (pages 99-107).Two deposition-precipitation style methods of preparing zinc oxide supported dispersed gold materials for use as water-gas shift catalysts were examined, with some of the better formulated materials being tested for catalytic activity, and compared to World Gold Council Au/TiO₂ reference material and a commercial copper-based WGS catalyst (Cu/ZnO/AlO₃ - C 18-7 from Sud-Chemie). Materials Synthesis: The classical deposition-precipitation synthesis from the group of Haruta (Tsubota et al., 1995) - where the support is added to a pH adjusted solution of HAuCl₄ and the system aged at constant pH and temperature - was examined, using ZnO as the support. Gold uptake by the support was confirmed to decrease with ageing pH, tending to zero as the IEPS of ZnO (~ 9) is approached. Such behaviour is both qualitatively and quantitatively consistent with theory, which proposes that the magnitude and polarity of the charge on the support surface will determine the effective carrying capacity of that surface for an (an)ionic solution phase gold species. Decreasing post-calcination (120°C) gold crystallite size with increasing ageing pH [as reported by Haruta (1997)] was also observed (figure 11.2) - but it is not clear whether this resulted from pH dependent crystallization dynamics, from crystallite size being simply determined by the amount of deposited gold (which clearly decreases with increasing pH), or from chloride induced sintering during heat treatment (with chloride uptake by the support decreasing with increasing pH [Kung et al., 2003)). Nevertheless, gold deposition at pH 8 produced highly dispersed gold crystallites around 3.5 nm in diameter. It emerged that an inherent trade-off exists with this, the classical depositionprecipitation method, in that acidic ageing pH promotes a high degree of gold uptake by the support, but produces large gold crystallites, and vice versa. To overcome this, a modified method - where HAuCI₄ and the base (ammonium carbonate) were simultaneously added dropwise to a slurry of the support, maintaining a constant pH of 8 (Fu et al., 2003b) - was investigated. This method was attractive because it is claimed to simultaneously achieve total gold uptake and post-calcination Au crystallite size in the range 5 - 6 nm. Since it was not clear from the published description whether a constant pH was maintained across the ageing period (practiced here as MDP1 ), or if the pH was rather allowed to drift (practiced here as MDP2), both alternatives were investigated. When a constant pH was maintained across the ageing period (MDP1 ), gold uptake by the support was found to reach a maximum (of ~ 60 %) when operating at a pH of ~ 8. The degree of gold uptake was found to be independent of both gold loading and support surface area. Furthermore, the degree of gold uptake achieved using this variation was increased to unity by allowing the pH to drift during the ageing period (after being initially held constant at 8 during HAuCI₄ addition) [= MDP2], instead of being maintained at a constant value via addition of nitric acid (as is done in MDP1). In terms of the size of the gold crystallites produced, after calcination in air at 400°C, a mean diameter of 3.8 ± 1.5 nm was observed for a sample 1.9 wt % in Au, increasing slightly with increasing gold loading [to 4.6 ± 1. 7 nm by 5.1 wt %Au].
28
Camp, Douglas Wayne. "The Preparation and Performance of Selected Schubert Songs for Bass Trombone and Piano." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195369.
Full textAbstract:
This document will examine how Schubert's songs can be used to increase the existing bass trombone solo literature. The primary focus is on the process of selecting, organizing, and arranging songs for the purpose of creating an original instrumental performance edition. The document will discuss elements that influence individual song selection, compositional attributes of the music, the drama represented through the text, and the boundaries these expressive components impose on the arranging process. The arranging process is discussed for nine individual songs including compositional elements which might influence the ordering of songs in a specific performance. A brief historic discussion overviews the role of the bass trombone in early nineteenth-century classical music, Schubert's life in regards to his contribution to song literature, and the influence of politics and economics during Schubert's life. An extensive Appendices contains a recommended list of Schubert lieder recordings, detailed text translations, bass trombone solo parts and full piano scores for all nine songs arranged for this document.
29
Li, Yifan, Caixin Cao, Ying Pei, Xueying Liu, and Keyong Tang. "Preparation and properties of microfibrillated chitin/gelatin composites - 133." Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34297.
Full textAbstract:
Content:
A microfibrillated chitin/gelatin composite film was prepared by solvent casting method, and the nanosized microfibrillated chitin as a reinforce phase to improve oxygen resistance, water-resistant and
mechanical performance in this system.The morphologies were analyzed by scanning electron microscope (SEM), and the mechanical properties were investigated by texture analyzer. Oxygen permeability
property, optical property and swelling property were investigated. The results indicated thatthe elastic modulus and tensile strength of microfibrillated chitin/gelatincomposite reached to 2.2GPa and 74.5MPa
respectively when the content of microfibrillated chitinis 8wt%. The swelling ratio decreased to 11.63 with the 6wt% content of microfibrillated chitin.In addition, chitin microfibrils effectively enhanced the oxygen
resistance of composite film without obvious loss of transmittance.
30
Kvåle, Hans Jørgen. "Competition preparation by terrain simulation in orienteering : Can terrain simulation of an embargoed terrain improve performance in orienteering?" Thesis, Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:gih:diva-2954.
Full textAbstract:
Abstract Aim The aim of this study was to examine if simulating an unknown competition terrain with the computer game Catching Features improved orienteers performance in the real terrain compared to a terrain they had not simulated. Method This study examined the effect of simulation by asking elite level orienteers to simulate an unknown terrain with a computer programme for approximately one hour per day, for six days prior to an orienteering test. The participants were divided into two matched groups and one group simulated one forest terrain while the other group simulated another forest terrain. On the test day the participants ran one course in each forest terrain, in a crossover-type design. Results This study shows that simulation of an unknown terrain did not statistically significant increase an orienteers performance, however it had a small effect on orienteering and navigational performance indices. The use of simulation also had a large impact on how well the participants felt they prepared for the race. Conclusions Although simulation of an unknown terrain increases an orienteer’s self-rating of prior knowledge of the terrain, there was no clear improvement in race performance. Terrain simulation had a small effect on navigational performance, possibly at the cost of a slower running speed. This may have been as a result of an increased awareness of the difficulty to relocate in the terrain after simulation, which may have prompted orienteers to try to follow a more detailed terrain model to avoid navigational errors. Following a more detailed model may have cost them as much time as they gained from not making mistakes and this resulted in no change in race performance. In the flat terrain that was tested there were not many challenging route choices and it was not possible to detect any effect on the route choice performance by simulation.
31
Huen, Man-kit, and 禤文傑. "Protocol development for the quality control of multi-component Chinese herbal preparation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B2973891X.
Full text
32
Shipard, Rachael Catherine Lee. "Enhancing musical practice and performance in a variety of contexts: An autoethnographic investigation." Thesis, Griffith University, 2019. http://hdl.handle.net/10072/386110.
Full textAbstract:
This research project involved an autoethnographic investigation of strategies that can improve practice and pre-performance routines. Although much research has already been conducted in the area of optimal performance (Wrigley & Emmerson, 2011; Freedman, 2015; Groth, 2016; Csikszentmihalyi, 1990), this study is conducted from my own personal viewpoint as a young classical pianist, to improve the reliability and consistency of my performances, and enhance my satisfaction with them.Thesis (Masters)
Master of Music Research (MMusRes)
Queensland Conservatorium
Arts, Education and Law
Full Text
33
Williams, Bede. "Preparation, rehearsal, performance and reflection : a conductor's autoethnographical study of the process of interpretation." Thesis, University of St Andrews, 2018. http://hdl.handle.net/10023/15665.
Full textAbstract:
In this study the author investigates his interpretive practice as a conductor, revealing how interpretive operations occur not as discrete and isolated activities, but rather an intertwined cyclic process. The study was based on an experiment of the author conducting five scores on two different occasions separated in time by between one day and several months. The study design included extensive content analysis of over 30 hours of video in which more than 12,000 codes were applied and collated. The study design also included traditional texted research, autoethnographic writing (a 25,000-word practice journal), semi-structured interviews, the use of Sonic Visualiser, and the documentation of a range of score study methods which the author describes as ‘listening in silence'. Although there are numerous studies that compare different performances of the same piece, and consider the extent to which differences are intentional and/or creative, none has been undertaken by a conductor in the role of artist-researcher. The study develops what the author calls the ‘ethos of multiple interpretability', suggesting that a conductor can be ‘animated by' the belief that there is no single correct way to perform a work specified by a score.
34
Macedo, Pedro Lopes da Silva [UNESP]. "A preparação para performance de livre improvisação no contrabaixo." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/141915.
Full textAbstract:
Submitted by PEDRO LOPES DA SILVA MACEDO null (umagoma@gmail.com) on 2016-07-21T17:27:55Z
No. of bitstreams: 1
Dissertação Final Entrega.pdf: 1228145 bytes, checksum: b6cbf98c3c7f226762d43d7450907eb0 (MD5)Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-25T18:43:01Z (GMT) No. of bitstreams: 1 macedo_pls_me_ia.pdf: 1228145 bytes, checksum: b6cbf98c3c7f226762d43d7450907eb0 (MD5)
Made available in DSpace on 2016-07-25T18:43:01Z (GMT). No. of bitstreams: 1 macedo_pls_me_ia.pdf: 1228145 bytes, checksum: b6cbf98c3c7f226762d43d7450907eb0 (MD5) Previous issue date: 2016-06-17
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A improvisação livre, por suas características sui generis, traz ao campo da preparação para performance uma problemática diversa daquela encontrada a partir do seu estudo fundado na música tradicional, idiomática, seu objeto preferencial. Este trabalho investiga os elementos e a eficácia da preparação para a performance do contrabaixo na improvisação livre, visando a um só tempo contribuir para o estudo da preparação para performance musical, como também fornecer subsídios para a preparação e prática da improvisação livre no contrabaixo. A partir de uma revisão bibliográfica sobre os temas da improvisação livre e da preparação para performance, busca-se definir os elementos específicos necessários à preparação para performance da improvisação livre, fazendo uma análise de sua aplicação na preparação para performance musical. Discute-se também as bases conceituais da improvisação livre, buscando uma maior compreensão desta prática. Por fim, sugere-se guias para a prática da improvisação livre no contrabaixo através de estratégias e exercícios, com o intuito de estimular o conhecimento e o uso desta prática entre estudantes e músicos em geral.
Free improvisation, regarding its unique characteristics, brings to the performance field of research a diverse problematic that is found in studies based on the traditional, idiomatic music, its preferential object. This work investigates the elements and efficiency of the free improvisation performance preparation on the double bass, aiming both to contribute to the musical performance study and to provide subsidies to the free improvisation preparation and practice on that instrument. From a literature review on the themes related to the free improvisation and performance preparation, this paper seeks to define the specific elements needed to the free improvisation performance preparation, analyzing its application in musical performance, broad sense. It also discusses the conceptual basis of the free improvisation, in order to enlarge this practice’s comprehension. Guides to the initial approach to free improvisation on the double bass are presented, in order to stimulate the student and general musician to this practice.
35
Sengul, Erce. "Preparation And Performance Of Membrane Electrode Assemblies With Nafion And Alternative Polymer Electrolyte Membranes." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608734/index.pdf.
Full textAbstract:
Hydrogen and oxygen or air polymer electrolyte membrane fuel cell is one of the most promising electrical energy conversion devices for a sustainable future due to its high efficiency and zero emission. Membrane electrode assembly (MEA), in
which electrochemical reactions occur, is stated to be the heart of the fuel cell. The aim of this study was to develop methods for preparation of MEA with alternative polymer electrolyte membranes and compare their performances with the conventional Nafion®membrane. The alternative membranes were sulphonated polyether-etherketone (SPEEK), composite, blend with sulphonated polyethersulphone (SPES), and polybenzimidazole (PBI). Several powder type MEA preparation techniques were employed by using Nafion®
membrane. These were GDL Spraying, Membrane Spraying, and Decal methods. GDL Spraying and Decal were determined as the most efficient and proper MEA preparation methods. These methods were tried to improve further by changing catalyst loading, introducing pore forming agents, and treating membrane and GDL. The highest performance, which was 0.53 W/cm2, for Nafion®
membrane was obtained at 70 0C cell temperature. In comparison, it was about 0.68 W/cm2 for a commercial MEA at the same temperature. MEA prepared with SPEEK membrane resulted in lower performance. Moreover, it was found that SPEEK membrane was not suitable for high temperature operation. It was stable up to 80 0C under the cell operating conditions. However, with the blend of 10 wt% SPES to SPEEK, the operating temperature was raised up to 90 0C without any membrane deformation. The highest power outputs were 0.29 W/cm2 (at 70 0C) and 0.27 W/cm2 (at 80 0C) for SPEEK and SPEEK-PES blend membrane based MEAs. The highest temperature, which was 150 0C, was attained with PBI based MEA during fuel cell tests.
36
MacNeill, Karen C. "Processes contributing to optimal preparation and performance of Winter Olympic athletes : the athletes' story." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31422.
Full textAbstract:
The purpose of this investigation was to explore the processes that contribute to optimal preparation and optimal performance of an athlete competing at the Winter Olympic Games. Using narrative methodology, 4 individual sport athletes (2 male, 2 female) who competed at the 2006 Winter Olympic Games in the sports of skeleton, snowboarding, and long track speed skating (one on the all-round team and another on the sprint team) were interviewed using an in-depth, open-ended, semi-structured approach (Rubin & Rubin, 1995). The semi-structured research interview lasted approximately 2-2.5 hours in length, and participants were contacted a second time via email once the data had been analyzed to verify accurate representation of their experience. The qualitative data was analyzed using Lieblich, Tuval-Maschiach, and Zilber (1998) categorical-content narrative analysis approach, which is similar to what is commonly known as content analysis. Narrative accounts, or the athletes' Olympic stories, were also developed through this process. From the narrative analysis, seven themes emerged concerning processes contributing to optimal preparation, and six themes emerged regarding processes contributing to optimal performance. The findings reveal that for optimal preparation of an Olympian, there needs to be development and implementation of a strategic, holistic plan that incorporates processes for balance and recovery, support and mentoring, automating skill and establishing familiarity, and for reflection and monitoring to ensure training potentials are being maximized and that valuable lessons are being extracted. Furthermore, processes contributing to optimal performance at the Olympics require highly functioning self-regulation practices; a level of self-knowledge and self-acceptance that allows detachment from the outcome and freedom to perform authentically; confidence and belief in ability to achieve excellence; perspective, and acceptance and adaptation to current experiences and conditions; focus and engagement in the present moment; and the execution of performance strategies that lead to a high level of performance excellence. Implications for athletes, coaches, and practitioners are discussed, and suggestions for future research are provided.Education, Faculty of
Educational and Counselling Psychology, and Special Education (ECPS), Department of
Graduate
37
Nawaz, Sohail. "Preparation and long-term performance of poly(ethylene-co-butyl acrylate) nanocomposites and polyethylene." Doctoral thesis, KTH, Polymera material, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104685.
Full textAbstract:
The current study discusses the preparation and long-term performance of polymer composites used for various purposes under different ageing conditions. The first part deals with the preparation and characterization of polymer nanocomposites based on poly(ethylene-co-butyl acrylate) (EBA–13 and EBA–28 with 13 and 28 wt % butyl acrylate, respectively) and 2–12 wt % (0.5–3 vol %) of aluminum oxide nanoparticles (two types with different specific surface areas and different hydroxyl-group concentrations; uncoated and coated with, respectively, octyltriethoxysilane and aminopropyltriethoxysilane). The nanocomposite with EBA–13 showed better overall nanoparticle dispersion while EBA–28 resulted in poor dispersion, probably due to insufficiently high shear forces acting during extrusion mixing which were unable to break down nanoparticle agglomerates. The activity of hindered phenolic antioxidant (0.2 wt%) in all EBA nanocomposites was assessed by determining the oxidation induction time using DSC. The composites containing uncoated aluminium oxide nanoparticles showed a much shorter initial OIT than the pristine polymer with the same initial concentration of antioxidant, indicating adsorption of antioxidant onto the nanoparticle surfaces. Composites containing coated nanoparticles showed a significantly smaller decrease in the initial OIT, suggesting the replacement of hydroxyl groups with organic silane tails, decreasing the concentration of available adsorption sites on the nanoparticle surfaces. The decrease in OIT with increasing ageing time in dry air at 90 °C of the nanocomposites was slower than that of the unfilled pristine polymer, suggesting a slow release of antioxidant from adsorption sites. The EBA nanocomposites exposed to liquid water at 90°C showed faster decrease of OIT than samples exposed to dry or humid air. The migration rate of antioxidant was controlled by the boundary conditions in the case of ageing in humid air and liquid water. The antioxidant diffusivity was lower for the composites containing uncoated ND than for the composites containing ND coated with octyltriethoxysilane or aminopropyltriethoxysilane. The migration and chemical consumption of deltamethrin DM, (synthetic pyrethroid) and synergist piperonyl butoxide from molded polyethylene sheets was also studied. Deltamethrin and piperonyl butoxide are often used for food storage and insect control purposes. DM showed no signs of crystallization and remained in a liquid state after being cooled to room temperature. Exposure of polyethylene compound sheets to liquid water (at 80 & 95 °C), caused degradation and hydrolysis of the ester bond in the DM, present in the prepared material, and generated species containing hydroxyl groups. Liquid chromatography and infrared spectroscopy showed a significant migration of the active species in liquid water, whereas in air at 80 °C (60 and 80 %RH) the loss of DM and PBO was negligible over 30 days. The long-term performance of medium-density polyethylene stabilized with six different phenolic antioxidants (0.1 wt%) in aqueous chlorinated media at 70 °C was studied. The results were compared with data for previously studied solutions of antioxidants in squalane (a liquid, low molar mass analogue of polyethylene). A linear relationship was established between the time to reach antioxidant depletion in polyethylene tape samples and the time in squalane samples. Infrared spectroscopy and scanning electron microscopy of drawn samples revealed the onset of surface oxidation and surface embrittlement in tape samples exposed beyond the time for antioxidant depletion.QC 20121109
Cable insulation materials
Loss of deltamethrin and pipronyl butoxide from polyethylene
long-term performance of polyethylene in chlorine dioxide water
38
Xie, Qin, and 谢琴. "Test design and use, preparation, and performance: a structural equation modeling study of consequentialvalidity." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44548692.
Full text
39
Fitzpatrick, Joanne. "The performance of senior student nurses from different programmes of preparation : an exploratory study." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338690.
Full text
40
Reed, William Donald. "THE EFFECTS OF TEACHER MATHEMATICS PREPARATION ON STUDENT PERFORMANCE IN THE MIDDLE LEVEL SCHOOLS." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183781.
Full textAbstract:
This study was conducted to determine if varying amounts of mathematics preparation and varying attitudes toward mathematics by teachers had a significant effect on the mathematics performance of their eighth grade students. Mathematics preparation was determined by the total number of college credits a teacher had accumulated and attitude toward mathematics was determined by a survey using the Revised Math Attitude Scale authored by Aiken and Dreger in 1961. In addition to mathematics preparation and attitude, the teacher characteristics of sex, age, years of experience, ethnicity, and type of certification were also observed and analyzed in relation to student performance. The sample population consisted of 30 eighth grade teachers from 10 middle schools in a large southwestern metropolitan school district and their 1,368 students. Student performance was measured by using the student math scores from the Iowa Test of Basic Skills. All variables in the study were tested at the .05 level of confidence using multiple regression and analysis of variance. None of the variables were significant predictors of student performance when the teachers were analyzed as an entire group. When divided into subgroups by student achievement levels, teachers with greater amounts of preparation had a significant effect at the .05 level of confidence with high achievement students; teachers with high attitudes toward mathematics had a significant effect at the .05 level of confidence for students of medium achievement. All other variables were insignificant for the subgroups. Conclusions were drawn that the individual teacher characteristics examined were not significant predictors of student performance unless students were grouped by achievement levels. This indicated that "more" in terms of math preparation for teachers or the concept of being a specialist at the middle school level was not a significant predictor of teacher effectiveness.
41
Marsh, Donald. "Changes in Psychological, Morphological, and Performance Characteristics in Preparation for a National Weightlifting Competition." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/etd/3642.
Full textAbstract:
The primary aim of this study was to examine the time course of change in muscle morphology and vertical jump performance in weightlifters preparing for a national competition. The secondary aim of this study is to examine how perceived recovery and stress state corresponds with alterations in training load leading up to competition. Eleven Olympic Training Site weightlifters completed a 4-week peaking phase for a national competition. Body mass, stress and recovery psychometric measures, and unloaded/loaded (20kg) squat jump height (SJH) were measured weekly and at the competition site. Vastus lateralis cross-sectional area (CSA), muscle thickness (MT) and pennation angle (PA) ultrasound measurements were taken prior to and following the training protocol. In competition, 6 athletes set a personal best in snatch, clean and jerk and/or total. These results suggest that improvements in the loaded SJ and psychometric measures correspond to successful competition performance in some weightlifters. Notably, most weightlifters appeared to be peaked within 3 days of competition.
42
Sung, Huan-Hsin, and 宋寰欣. "CIGS preparation and device performance." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2mqjhg.
Full textAbstract:
博士國立中興大學
材料科學與工程學系所
106
This study aims to prepare a CuIn1-xGaxSe2 (CIGS) absorber layer, and the device characteristics in different processes are discussed. This study is mainly divided into 7 chapters. In Chapter 3, the Ga gradient behavior of CIGS thin films prepared through selenization of a CuGa/In-stacked elemental layer is studied. Cu11In9, Cu2Se, In2Se3, and chalcopyrite phases are observed from room temperature to 230°C. A single-chalcopyrite phase slowly forms when the selenization temperature is increased from 230°C to 510°C. A conversion efficiency of 2.56% can be achieved through a sputtering/selenization process. The three-stage process of structure evolution of CIGS thin films and the device performance are studied in Chapter 4. The precursor of γ-(In,Ga)2Se3 phase can be found in the first stage. The γ-(In,Ga)2Se3 phase is transformed into β-Cu(In,Ga)3Se5 when Cu2-xSe is deposited in the second stage. Then, a α-Cu(In,Ga)Se2 is gradually formed when saturation stoichiometric ratio is reached. As the excess Cu2-xSe is deposited, phase separation of CIGS/Cu2-xSe is formed on the film surface. Next, (In,Ga)2Se3 is deposited to eliminate the excess Cu2-xSe phase on the surface at the third stage. In this study, the highest conversion efficiency of 10.97% can be obtained when the [Cu]/([In]+[Ga] ratio of 0.98 used. In Chapter 5, the surface properties and composition distribution of CIGS absorber layer are studied using different thickness of (In, Ga)2Se3 deposited during the third stage. The (In,Ga)2Se3 thickness is adjusted from 200 nm to 450 nm and we find the distribution of Cu and Ga could be optimized when (In,Ga)2Se3 of 350nm-thick is used. Finally, the highest conversion efficiency achieved for [Cu]/([In]+[Ga]) ratio of 0.98 is 15.82%. In Chapter 6, a Na source via a MoNa intermediate layer is studied to prepare a CIGS absorber layer on Na-free substrate for a three-stage evaporation process. The performance of CIGS solar cell with different thicknesses of MoNa layer is investigated. An appropriate thickness of MoNa layer as sodium source is helpful to provide carrier concentration on a Na-free substrate.
43
Tang, Ling-Chih, and 黨苓之. "Preparation of high-performance lithium-ion battery." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/56935532519193877357.
Full textAbstract:
碩士國立中央大學
化學研究所
98
The cathode of Li-ion battery after charge-discharged can produce a special structure named solid electrolyte interface (solid electrolyte interface, SEI), which helps lithium ion transmission during charge and discharge process, and improves the electrode stability. Charge capacity and safety can also be improved by improving SEI structure. The research presents two approaches to the improvement of SEI structure with the aim to produce high performance and safe lithium battery. This study is divided into two parts. The first part describes the modification of SEI through the addition of conducting polymer, which enhances both the C-rate capacity and cycle life. After screening several monomers, the thiophene monomer derivatives: 3,4-Ethylenedioxythiophene (EDOT) is found to be most effective for this purpose after electrochemical polymerization on the cathode surface. The conductive polymer is composed of electronic conducting main chain and ion conductive side-chain, enabling an efficient charge transfer on the interface of the LiFePO4 cathode particles. The addition, EDOT has effectively improved the C-Rate capability and life cycle. The improvement is found to increase with EDOT concentration but optimized at certain threshold. In presence of excess EDOT, longer activation cycle (during which polymerization is achieved) will be required to completely polymerize EDOT, and the interface may be too thick whcih blocks the litium insertion. In this system, 0.03M is the optimized concentration. The second part of the study is to improve lithium battery safety feature with the addition of functional molecules in the electrolytes. LiCoO2 is the most widely used cathode material in commercial lithium ion batteries, but the safety remains an issue which urgently needing improvement. In this research, barbituric acid (BTA) and its derivatives as well as conducting polymer were added to the electrolyte to improve lithium battery safety. The delay of exothermic temperature can be observed by differential scanning thermal calorimetry (DSC). Carefully balancing the component composition, it is found the battery performance and safety features can both be enhanced. Conventional safety technology uses flame retardants to reduce electrolyte flammability, temperature control is not satisfactory, and the charge capacity usually suffers greatly. In contrast, present approach achieved the thermal stability while still maintaining the charge capacity and long cycle life.
44
Lee, Chi Hua, and 李琪華. "Preparation , Performance and Characterization for Zeolite Adsorbent." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/68779588975490480836.
Full textAbstract:
碩士國立中正大學
化學工程研究所
91
Volatile-organic-compounds (VOCs) containing waste gas are normally controlled by condenser , wet scrubber , activated-carbon absorber , regenerative thermal oxidizer(RTO) ,catalytic oxidizer (CAO) , and zeolite rotor concentrator . Among them , zeolite rotor concentrator is the most popular one . However , because of the complexity in pollutant , the rotor is suffered by quick deactivation cased by destruction of Zeolite . The drawbacks motivate us to develop a high performance and regenerable adsorbent . The main function for VOCs adsorption is still Zeolite . However , by controlling pore diameter and hydrophobic properties of matrix (binder for adhering zeolite) , an adsorbent can be tailored for a specific requirement. Moreover , for the utilization in waste gas of low concentration high flow rate , adsorbent of hollow cylinder in shape was prepared by a screwing-extruding forming machine of laboratory scale for performance test and the machine was further scale up to commercial scale for industry application . The adsorbent was characterized by TPO (temperature-programmed-oxidation) , TPD(temperature-programmed desorption) , XRD (x-ray diffraction) , SEM (scan electron microscopy) , and adsorption performance test . For different kind of zeolite or spent zeolite, namely , Y zeolite, ZSM-5, ROC, and FCC spent catalysts, have been tested . The adsorption capacity for these 4 zeolite is in the order: Y > ZSM-5>ROC and FCC . It may be caused by the pore mouth plugging during adsorbent preparation, the adsorption capacity of ZSM-5 is not as high as we expected, whereas the performance adsorbent made from Y was good enough for considering commercial run and the formulation for preparation was further tuning with the guide of the complemented characterization tools . In addition , the regenerability was test with cycled accelerated aging tests and the results indicated that after 6 cycles , no significant deactivation was observed . In viewing of these results , a large scale of adsorbent was prepared based on the formula developed in the lab . And the test results showed that the performance , including mechanical strength and adsorption capacity , of the sample prepared from commercial scale was even better . In the coming future , different adsorbent will be developing for handling VOCs of variety properties, and hopefully the performance of the adsorbent will also be tested in commercial run .
45
LAI, CHUN-TING, and 賴俊廷. "The Preparation and Performance of Pellet Catalyst andAdsorbent." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/2w9sdv.
Full textAbstract:
碩士國立中正大學
化學工程研究所
105
The goal of this research is to prepare granular Pt catalysts and adsorbent for hydrogenation isomerization of toluene and for NH3 removal, respectively.Hi-sil silica was used as binder precursor for the preparation of zeolite supports.The Pt catalysts were prepared by incipient wetness impregnation method. With the bifunctional active sites, toluene and be saturated and then followed with isomeration to prepared environmentally benign isomer solvents. Activated carbon GAC830 and Amberlyst 35 were used as adsorbent supports. After the impregnation of phosphoric acid, the adsorbents were used to remove ammonia gas via chemical reaction and/or adsorption. After the performance tests, the results revealed that binder preparation method greatly influenced the catalytic properties of the Pt catalysts for hydrogenation isomerization while pore diameter affected NH3 removal efficacy. Pt catalysts prepared from high Si/Al ratio HY zeolite bound with silica gel formed from high-pressure hydrothermal treatments exhibits higher isomer yield and lower fuel gas formation than that prepared from HY zeolite material with low Si/Al ratio and binder formed from acid digestion of Hi-sil silica. In addition, Pt catalysts prepared from other zeolite, such as ZSM5, do not present as good performance as that prepared from HY zeolite. For both adsorbents, phosphoric impregnatedGAC830 (H3PO4/C) and Amberlyst 35 (H3PO4/A) adsorbents, amount of NH3 removal was proportional to water containing in the adsorbents. Synchrotron PXRD characterizing used adsorbents indicated that (NH4)2HPO4 crystals formed on the activated carbon containing 12.69%、19.19% water. As water was decreased to 11.76% (NH4)H2PO4 crystals were formed. On further decreasing water to 11.34%, no ammonium phosphate crystals were formed and the NH3 removal was mainly from adsorption instead of chemical reaction. The results suggested that pore-mouth plugging resulting in a decrease of NH3 removal capacity. Hence, H3PO4/A with much larger pores with respect to H3PO4/C shows higher performance in that the treatment capacity for H3PO4/A is 3 times that of H3PO4/C.
46
Chen, Jia-Xing, and 陳佳杏. "Preparation and Performance of Minimodule Hollow Fiber Dialyzer." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/49863316380978609181.
Full text
47
KUO, WEI-HSIN, and 郭韋鑫. "Forward osmosis membrane preparation and filtration performance evaluation." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/35263043528910231759.
Full textAbstract:
碩士明志科技大學
環境與安全衛生工程系環境工程碩士班
105
Scarcity of water source arising from geographical conditions, speedy urbanization and extreme climate has threatened a lot of people on earth. Meanwhile, the limited fossil fuel and boosting energy price in the past decade worsen the acquirement of drinking water. The forward osmosis (FO) mainly driven by the natural osmotic pressure gradient have received much attention recently because of the simultaneous advantages of lower energy demand and membrane fouling tendency, compared to the reverse osmosis (RO) conventionally applied in the drinking water production. However, FO water purification technology is not yet mature, need to study and explore, making it a better water purification technology. Moreover, new membrane development is one of the most important breakthrough points for FO application. This study was aimed to fabricate several FO membranes using various material and approaches, study their filtration performance, and contaminant retention performance for water purification. First, a reaction tank for FO filtration process was designed and assembled. Both commercial RO membrane teared of the surface dense layer and the electrospinning supporting layer were adopted in this study. To obtain the contaminant retention and hydrophilicity enhancement, the interfacial polymerization and plasma grafting methods were respectively applied for the surface dense layer fabrication and membrane surface post-conditioning. Use the deionized water and campus effluents as feed solution (FS) and 1M NaCl solution as the draw solution(DS). The results revealed that the membrane with interfacial polymerization could significantly promote both the water flux and contaminant retention. The plasma grafting amine on the dense layer also enhance the water flux because of the hydrophilicity of membrane increasing. Through the ion chromatography analysis of FS (both for DI water and campus test sets) after filtration test, it was found that without dense layer of both RO membrane and electrospinning membrane reverse salt diffusion was higher than that with dense layer membrane. Comparing the water flux of membrane water permeability and reverse salt diffusion of electrospinning membrane and RO membrane, electrospinning membrane showed the slightly better performance than that of RO membrane.
48
Chun-Hsi, Huang, and 黃俊熹. "Preparation and Performance Study of Chitosan/PTFE Composite Membranes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/70244595286618129659.
Full textAbstract:
碩士元智大學
化學工程學系
93
In this study, we prepared PTFE/chitosan composite membranes by impregnating porous PTFE membrane in chitosan solutions. The thermal properties, ionic resistance, gas permeability, methanol permeability, and morphology of composite membranes were investigated and reported in this thesis. Two solutions of different chitosan concentrations were used to preapare composite membranes,i.e. 1 wt% and 1.5 wt%. The results show that the composite membrane prepared from 1.5 wt% chitosan solutions has a higher conductivity than that prepared from 1 wt% chitosan solution. The gas permeability of the composite membranes is higher than that of Nafion 117, but the methanol permeability at room temperature is low than that Nafion 117. The performance of H2/O2 single fuel cell prepared from composite membrane is lower than that from Nafion 117.
49
Paddock, Christopher D. "Performance work statements: significant problems in the preparation process." Thesis, 1987. http://hdl.handle.net/10945/22414.
Full text
50
Chung, Pao-Chia, and 鍾嘉寶. "Preparation of LiFePO4 Composite Cathode Material and Performance Analysis." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/31716386724887233983.
Full textAbstract:
碩士國立新竹教育大學
應用科學系碩士班
99
In this project, we use ferrous sulfate / hydrogen peroxide and phosphoric acid / ammonia as the starting materials to produce iron phosphate precipitates under pH value in 2. After mixing with lithium carbonate in a certain percentage, the precursors were sintered at 700℃ in nitrogen. Then we obtained the crystal-like good olivine lithium iron phosphate. We also added different dispersants / iron phosphate coating agent in the precipitation process, to study the influence of electric properties of products. The results indicated: the selected dispersant, can achieve a well dispersion, particle size in 100nm for all products. When adding PEI as the coating agent, the electric capacity of products can be improved. But if adding PEI coating agent with the dispersant in the same time, they did not necessarily obtain a better effect. Only in case of NSFC with PEI can be best, capacitance up to 141 mAh/g.