Dissertations / Theses on the topic 'Electrodes, Carbon – Design and construction'
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1
Dennison, John Robert. "(e,2e) spectroscopic investigations of the spectral momentum densities of thin carbon films." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/53869.
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An (e,2e) electron scattering spectrometer has been constructed and used for the first time to investigate the spectral momentum density of the valence bands of a solid target. This technique provides fundamental information about the electronic structure of both crystalline and amorphous solids. The three fundamental quantities, the band structure, electron density of states, and electron momentum distribution can be simultaneously derived from the measured (e,2e) cross section.
A review of single electron and (e,2e) scattering theory is given with an emphasis on scattering from solids. The effects of multiple scattering are discussed and a method of deconvoluting those effects from the measured (e,2e) cross section is developed.
There is a detailed description of the spectrometer design and operation with particular attention given to the electron optics and voltage distribution. The algorithms and software for computer aided data acquisition and analysis are also outlined, as is error analysis.
The techniques employed in the preparation and characterization of extremely thin film samples of a-C and single crystal graphite are described.
An analysis of the data taken for a-C samples is given. The data are compared with the results of complementary experiments and theory for graphite, diamond, and a-C which are given in a review of the literature. The existence of a definite dispersion relation ε(q) in amorphous carbon is demonstrated. The a-C band structure appears to be more similar to that of graphite than to that of diamond, however it differs significantly from both in some respects. The measured spectral momentum density seems compatible with a model of a-C based on small, randomly-oriented islands of quasi-2D graphite-like continuous random network structures. However, no definitive interpretations can be made until higher resolution experiments are performed on both a-C and single crystal graphite.Ph. D.
2
Temur, Roberto. "Tool-electrodes design and construction for electrochemical machining." Thesis, Bucks New University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251330.
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Bostanci, Sevket Can. "Low carbon sustainable concrete design and construction." Thesis, Kingston University, 2015. http://eprints.kingston.ac.uk/34545/.
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Li, Sinan. "DESIGN AND CONSTRUCTION OF NANOARCHITECTURAL METAL DERIVATIVES-CARBON NANOTUBE HYBRIDS." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1195248061.
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Su, Xin. "NOVEL DESIGN OF FUNCTIONALIZED CARBON NANOTUBE ELECTRODES AND MEMBRANES FOR FUEL CELLS AND ENERGY STORAGE." UKnowledge, 2012. http://uknowledge.uky.edu/cme_etds/5.
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A novel electrochemical method to generate nm-scale bubbles at the tips of CNTs can temporarily block the membrane. A 92% blocking efficiency is achieved when the bubbles are stabilized in 30-60 nm diameter „wells‟ at the tips of CNTs. This well is formed by the electrochemical oxidation of the conductive CNTs partially into the polymer matrix of the membrane. Meanwhile, the nanoscale bubbles can be removed with 0.004 atm pressure to recover the transport through the CNT membrane. The CNT membrane with nanoscale bubble valve system was used to demonstrate electrochemical energy storage.
Uniform ultrathin Pt films were electrodeposited onto an aligned array of carbon nanotubes (CNTs) for high-area chemically stable methanol fuel cell anodes. Electrochemical treatment of the graphitic CNT surfaces by diazonium benzoic acid allowed for uniform Pt electroplating. The mass activity of the Pt thin film can reach 400 A/g at a scan rate of 20 mV/s and in a solution of 1 M CH3OH/0.5 M H2SO4. A novel programmed pulse potential at 0 V was also seen to nearly eliminate the effects of carbon monoxide poisoning on catalyst Pt. Furthermore, the Pt monolayer was deposited on buckypaper by replacing the precursor Cu monolayer coated on CNTs by the underpotential deposition. The electrochemical surface modification of graphite CNTs by fluorinated benzoic acid was critical to coordinate Cu ions for monolayer formation. The mass activity of the monolayer can be improved to the record value of 2711 A/g. This is about 13 times higher than that of the ~10 nm thick Pt film coated on MWCNTs. Besides the high mass activity, the Pt monolayer coated on buckypaper can be used as catalyst for fuel cells with several advantages such as low cost, high surface area, flexibility, mechanical robustness and enhanced pressure flow.
Finally, a new strategy has been developed toward electrochemical water oxidation with Ir complexes catalyst, which was grafted on buckypaper by direct binding to enhance catalyst activity. The TOF (turn over frequency) of the Ir catalyst for water splitting was 7.9 s-1 at the constant potential of 1.4 V vs Ag/AgCl.
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Agarwal, Ritesh. "Design and Modeling of a Novel Direct Carbon Molten Carbonate Fuel Cell with Porous Bed Electrodes." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51251.
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A novel concept has been developed for the direct carbon fuel cell (DCFC) based on molten carbonate recirculating electrolyte. In the cathode, co-current flow of electrolyte with entrained gases carbon dioxide and oxygen is sent in the upward direction through a porous bed grid. In the anode, co-current flow of a slurry of electrolyte entrained with carbon particles is sent in the downward direction through a porous bed grid. The gases carbon dioxide and oxygen in the cathode react on the grid surface to form carbonate ions. The carbonate ions are then transported via conduction to the anode for reaction with carbon to produce carbon dioxide for temperatures under 750 deg C.
A mathematical model based on this novel DCFC concept has been developed. The model includes governing equations that describe the transport and electrochemical processes taking place in both the anode and cathode and a methodology for solving these equations. Literature correlations from multi-phase packed-bed chemical reactors were used to estimate phase hold-up and mass transfer coefficients. CO production and axial diffusion were neglected.
The results demonstrated that activation and ohmic polarization were important to the cell output. The impact of concentration polarization to the cell output was comparatively small. The bed depths realized were of the order of 10cm which is not large enough to accommodate the economies of scale for a large scale plant, however thousands of smaller cells (10 m^2 area) in series could be built to scale up to a 10 MW industrial plant. Limiting current densities of the order of 1000-1500 A/m^2 were achieved for various operating conditions. Maximum power densities of 200-350 W/m^2 with current densities of 500-750 A/m^2, and cell voltages of 0.4-0.5 V have been achieved at a temperature of 700 deg C. Over temperatures ranging from 700 to 800 deg C, results from the modeled cell are comparable with results seen in the literature for direct carbon fuel cells that are similar in design and construction.Ph. D.
7
Zhang, Di, and 张笛. "Transparent electrode design and interface engineering for high performance organic solar cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/202360.
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With the growing needs for energy, photovoltaic solar cells have attracted increasing research interests owing to its potentially renewable, feasible and efficient applications. Compared to its inorganic counterparts, organic solar cell (OSC) is highly desirable due to the low-cost processing, light weight, and the capability of flexible applications. While rapid progress has been made with the conversion efficiency approaching 10%, challenges towards high performance OSCs remain, including further improving device efficiency, fully realizing flexible applications, achieving more feasible large-area solution process and extending the stability of organic device.
Having understood the key technical issues of designing high performance OSCs, we focus our work on (1) introducing flexible graphene transparent electrodes into OSCs as effective anode and cathode; (2) interface engineering of metal oxide carrier transport layers (CTLs) in OSCs through incorporating plasmonic metal nanomaterials ;(3)proposing novel film formation approach for solution-processed CTLs in OSCs in order to improve the film quality and thus device performance.
The detailed work is listed below:
1. Design of transparent graphene electrodes for flexible OSCs
Flexible graphene films are introduced into OSCs as transparent electrodes, which complement the flexibility of organic materials. We demonstrate graphene can function effectively as both the anode and cathode in OSCs:
a) Graphene anode: we propose an interface modification for graphene to function as anode as an alternative to using aconventional polymer CTL. Using the proposed interfacial modification, graphene OSCs show enhanced performance. Further analysis shows that our approach provides favorable energy alignment and improved interfacial contact.
b) Graphene cathode: efficient OSCs using graphene cathode are demonstrated, using a new composite CTL of aluminum-titanium oxide (Al-TiO2).We show that the role of Al is two-fold: improving the wettability as well as reducing the work function of graphene. To facilitate electron extraction, self-assembledTiO2is employed on the Al-covered graphene, which exhibits uniform morphology.
2. Incorporation of plasmonic nanomaterialsinto the metal oxide CTLinOSCs
By incorporating metallic nanoparticles (NPs) into the TiO2CTLin OSCs, we demonstrate the interesting plasmonic-electrical effect which leads to optically induced charge extraction enhancement. While OSCs using TiO2CTL can only operate by ultraviolet (UV)activation, NP-incorporated TiO2enables OSCs to perform efficiently at a plasmonic wavelength far longer than the UV light. In addition, the effciency of OSCs incorporated with NPs is notably enhanced. We attribute the improvement to the charge injection of plasmonically excited electrons from NPs into TiO2.
3. Formation of uniform TiO2CTLfor large area applications using a self-assembly approach
A solution-processed self-assembly method is proposed for forming large-area high-quality CTL films. Owing to the careful control of solvent evaporation, uniform film is formed, leading to enhanced OSC performance. Meanwhile, our method is capable of forming large-area films. This approach can contribute to future low-cost, large-area applications.published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
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Mears, Benjamin M. "Design, Construction and Testing of Pilot Scale Photobioreactor Subsystems." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1213028732.
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Chen, Yi S. B. Massachusetts Institute of Technology. "Lorentz force actuator and carbon fiber co-winding design, construction and characterization." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45772.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 66-67).
Carbon fiber composites are materials that present many benefits to engineering applications, ranging from aerospace to medicine. This thesis provides background on carbon fiber properties and manufacturing techniques, and outlines the methodology for manufacturing a co-wound carbon fiber and copper coil for use in linear Lorentz force actuators. A conventionally-wound, plastic-bobbin actuator coil and the new, co-wound coil were then tested to compare their electrical, thermal, and mechanical performance. In a needle-free injection application, the cowound coil demonstrated improved performance over the conventional coil configuration. The carbon fiber coil is lighter by 3.75 ± 0.155 grams, increases the transient heat transfer by 15.7 %, is 2.18 ± 0.13 times stiffer, and can survive a higher compressive force than the conventional plastic bobbin.
by Yi Chen.
S.B.
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Braiwish, Mohammad I. "Fabrication and packaging of carbon-dioxide-laser-induced long-period fiber grating devices." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/15033.
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Brooks, W. G. "The design, construction and test of a postbuckled, carbon fibre reinforced plastic wing box." Thesis, Cranfield University, 1987. http://hdl.handle.net/1826/3292.
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A postbuckled, carbon fibre reinforced plastic (CFRP)
wing box has been designed, manufactured and tested
for an aerobatic light aircraft, the Cranfield Al.
Methods of analysis have been evaluated including:
i) Non-linear finite element analysis for the
prediction o-f panel postbuckling.
ii) A simpler technique based on an effective
width method. This forms the core of a design program,
'oPTIMIST'. It predicts buckling loads, postbuckled
reduced stiffness and overall column failure of
co-cured hat stiffened panels. It then optimises the
con-Figuration of a box beam for minimum weight.
iii) The use of the effective width method allied
to a large scale, linear finite element analysis.
The work includes the development of a new method
o-F construction for composite box structures. The wing
skin sti-Ffeners and rib flanges are co-cured
together. Integral slotted Joint features are formed
in each part. The structure is then adhesively bonded
together. A full description of the manufacture o-F the
wing box is included.
The structure was also tested in a specially
designed rig. It was tested to ultimate design loads
in:
i) Positive bending to 13.33.
ii) Negative bending to -96.
iii) Pure torsion resulting from full aileron
load.
iv) Torsion with 96 bending.
The compression panels were seen to postbuckle and
recover in each load case. Results are compared with
theory, and with the original aluminium Al wing. The
structure is 257. lighter than its aluminium
counterpart.
Finally, suggestions are made for possible areas
of further research.
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Bessette, Norman F. II. "A mathematical model of a tubular solid oxide fuel cell." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/19260.
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Bland, Brian Wayne. "Design, construction, and evaluation of coal extraction pilot plant to manufacture coal based carbon pitch." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1683.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains xi, 144 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 91-93).
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Wickboldt, Walter Charles 1942. "SITE INVESTIGATION, DESIGN ANALYSIS AND CONTRACT SPECIFICATIONS FOR NEW SPILLWAY CONSTRUCTION, FRANCIS E. WALTER DAM, CARBON COUNTY, PENNSYLVANIA (GEOLOGIC MAPPING, SLOPE STABILITY)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276737.
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Montgomery, Shirley A. "A new profile for a familiar building : a carbon-neutral public library branch in Union Township in Anderson, Indiana." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1390313.
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Buildings can be built that use no energy from external power grids. They can be essentially carbon neutral in their environmental load, and they can be built and operated at fair market values. Although this may sound like a dream of the future, the World Business Council for Sustainable Development (WBCSD) is working toward making that dream a reality today. The Council announced on March 26, 2006 (Environment News Service) that it is forming an alliance of global companies to ensure that by 2050 all new buildings meet these standards.1The profession of architecture, at the beginning of the 21st century, finds itself in a position where architectural philosophies and methodologies must respond to the world changing events that are impacting our planet. This creative project outlines some of the methodologies used to create a carbon-neutral public library. Within a public library, architects respond to two of the primary concerns of this young century; the global need for a clean, livable planet and the proliferation of digital media and methods that are driving globalization as we are beginning to know it.The proposed new Union Township Branch of the Anderson Public Library seemed a logical subject for this Creative Project because much of the past work of our firm and much of my personal experience involved the design of public libraries. The carbon neutral concepts evolved gradually, after much study, and the goal of this creative project is that this particular library and many other sustainable libraries in the future will benefit from the concepts and methodologies outlined here, as those new buildings approach carbon neutrality.Department of Architecture
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Schumacher, Joshua David. "Design and Construction of Plasma Enhanced Chemical Vapor Deposition Reactor and Directed Assembly of Carbon Nanotubes." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000214.
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Zhang, Yuelan. "Synthesis and Characterization of Nanostructured Electrodes for Solid State Ionic Devices." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14000.
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The demands for advanced power sources with high energy efficiency, minimum environmental impact, and low cost have been the impetus for the development of a new generation of batteries and fuel cells. One of the key challenges in this effort is to develop and fabricate effective electrodes with desirable composition, microstructure and performance. This work focused on the design, fabrication, and characterization of nanostructured electrodes in an effort to minimize electrode polarization losses.
Solid-state diffusion often limits the utilization and rate capability of electrode materials in a lithium-ion battery, especially at high charge/discharge rates. When the fluxes of Li+ insertion or extraction exceed the diffusion-limited rate of Li+ transport within the bulk phase of an electrode, concentration polarization occurs. Further, large volume changes associated with Li+ insertion or extraction could induce stresses in bulk electrodes, potentially leading to mechanical failure. Interconnected porous materials with high surface-to-volume ratio were designed to suppress the stress and promote mass transport. In this work, electrodes with these unique architectures for lithium ion batteries have been fabricated to improve the cycleability, rate capability and capacity retention.
Cathodic interfacial polarization represents the predominant voltage loss in a low-temperature SOFC. For the first time, regular, homogeneous and bimodal porous MIEC electrodes were successfully fabricated using breath figure templating, which is self-assembly of the water droplets in polymer solution. The homogeneous macropores promoted rapid mass transport by decreasing the tortuosity. And mesoporous microstructure provided more surface areas for gas adsorption and more TPBs for the electrochemical reactions. Moreover, composite electrodes were developed with a modified sol-gel process for honeycomb SOFCs. The sol gel derived cathodes with fine grain size and large specific surface area, showed much lower interfacial polarization resistances than those prepared by other existing processing methods.
Nanopetals of cerium hydroxycarbonate have been synthesized via a controlled hydrothermal process in a mixed water-ethanol medium. The formation of the cerium compound depends strongly on the composition of the precursors, and is attributed to the favored ethanol oxidation by Ce(IV) ions over Ce(IV) hydrolysis process. Raman studies showed that microflower CeO2 preferentially stabilizes O2 as a peroxide species on its surface for CO oxidation.
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Stone, Richard C. "Design & construction study effectiveness of environmental tobacco smoke particulate and gas phase filtration in an environmental exposure chamber system /." abstract and full text PDF (free order & download UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1460780.
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Ashraf, Rehman. "Robust Circuit & Architecture Design in the Nanoscale Regime." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/240.
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Silicon based integrated circuit (IC) technology is approaching its physical limits. For sub 10nm technology nodes, the carbon nanotube (CNT) based field effect transistor has emerged as a promising device because of its excellent electronic properties. One of the major challenges faced by the CNT technology is the unwanted growth of metallic tubes. At present, there is no known CNT fabrication technology which allows the fabrication of 100% semiconducting CNTs. The presence of metallic tubes creates a short between the drain and source terminals of the transistor and has a detrimental impact on the delay, static power and yield of CNT based gates. This thesis will address the challenge of designing robust carbon nanotube based circuits in the presence of metallic tubes. For a small percentage of metallic tubes, circuit level solutions are proposed to increase the functional yield of CNT based gates in the presence of metallic tubes. Accurate analytical models with less than a 3% inaccuracy rate are developed to estimate the yield of CNT based circuit for a different percentage of metallic tubes and different drive strengths of logic gates. Moreover, a design methodology is developed for yield-aware carbon nanotube based circuits in the presence of metallic tubes using different CNFET transistor configurations. Architecture based on regular logic bricks with underlying hybrid CNFET configurations are developed which gives better trade-offs in terms of performance, power, and functional yield. In the case when the percentage of metallic tubes is large, the proposed circuit level techniques are not sufficient. Extra processing techniques must be applied to remove the metallic tubes. The tube removal techniques have trade-offs, as the removal process is not perfect and removes semiconducting tubes in addition to removing unwanted metallic tubes. As a result, stochastic removal of tubes from the drive and fanout gate(s) results in large variation in the performance of CNFET based gates and in the worst case open circuit gates. A Monte Carlo simulation engine is developed to estimate the impact of the removal of tubes on the performance and power of CNFET based logic gates. For a quick estimation of functional yield of logic gates, accurate analytical models are developed to estimate the functional yield of logic gates when a fraction of the tubes are removed. An efficient tube level redundancy (TLR) is proposed, resulting in a high functional yield of carbon nanotube based circuits with minimal overheads in terms of area and power when large fraction of tubes are removed. Furthermore, for applications where parallelism can be utilized we propose to increase the functional yield of the CNFET based circuits by increasing the logic depth of gates.
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Winski, David Nathaniel. "Design and construction of a polarization modulated infrared reflection absorption spectrometer and validation with carbon monoxide adsorption on a platinum (100) surface." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 96 p, 2009. http://proquest.umi.com/pqdweb?did=1889078511&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Salinas, Mejia Oscar Roberto. "An investigation of a carbon dioxide-based fuel cell system as a power generation alternative for Mars exploration applications." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12037.
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Odeh, Ahmad. "An Integrated BIM Model to Evaluate the Embodied Energy, Carbon Emissions & Environmental Costs of Construction Materials Used in the Design of Buildings." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41550.
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Currently, many researchers are looking at efficient ways to reduce energy and carbon emissions of construction materials used in buildings over their life due to its significant environmental impact. Along with operational energy, embodied energies and its associated carbon are substantial contributors in the overall sustainability assessment. The calculation of materials’ embodied energy and carbon emissions during the construction stage is a major assessment factor that needs to be considered to measure the environmental impact of materials used in the construction of buildings, which would provide designers with the ability to lower the environmental impact of buildings at the early design stage. Overall, it is rather complicated to compute embodied energy and carbon emissions due to the various factors involved. The tools and methodologies, listed in the literature, are rather imperfect as they tend to overgeneralize. The equipment used, fuel needed, and electricity required for each type of construction material varies from one location to another and thus embodied energy used, and carbon produced will differ for each construction project. Moreover, the method used in manufacturing, transporting and putting in place these materials will have significant influence on their environmental impact. This anomaly has made it difficult to calculate or even benchmark the usage of such factors. This thesis proposes an integrated model aimed at calculating embodied energies, embodied carbon and associated costs generated by construction materials based on such variability. This thesis presents a systematic approach that uses an efficient method of calculation to provide new insight for the selection of construction materials and equipment required to place them for buildings. Such assessment will aid in reducing the environmental impact of construction. The proposed model will be developed in a BIM environment. The quantification of materials’ energy is determined over the three main stages of their lifecycle: manufacturing, transporting, and placing. The proposed model will use multiple databases to calculate the energy used by manufacturing, transporting, and placing construction materials. By identifying the machinery required, an accurate calculation is achieved through geospatial data analysis. The proposed model can automatically calculate the distances between the material suppliers and construction sites to increase the accuracy of its outcome. Based on such variables, the proposed model provides designers with a list of equipment as to minimize the embodied energy and carbon produced by materials used in constructing buildings. Additionally, the proposed model has the ability to calculate the environmental cost impact of using specific building materials. Overall, this thesis aims to help researchers and the construction industry in reducing the environmental impact of construction activities through the selection of materials and the determination of machines required to achieve that goal.
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Fourie, Marna. "A subcritical and transcritical carbon dioxide refrigeration system utilizing multiple expansion devices." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86380.
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Thesis (MScEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Carbon dioxide is a natural gas that has been used as a refrigerant as far back as the 1850s. It was then primarily used because it was easily obtainable and non-toxic. Due to the high operating pressure and relatively low critical temperature (and high critical pressure) of CO2, it was gradually phased out and replaced with hydrochlorofluorocarbons and chlorofluorocarbons. With the discovery of the greenhouse effect, greenhouse gasses and ozone depleting gasses, the Montreal Protocol and the Kyoto Protocol were placed into effect. These two protocols call for the reduction in use of certain greenhouse gasses and the complete exclusion of others. The focus turned to natural gasses that are more environmentally friendly and easier to come by. Carbon dioxide is one such gas. However, CO2 has a low critical temperature and high pressure, 33.98 °C and 73.77 bar respectively. CO2 refrigeration systems are more effective, have a greater coefficient of performance and have a greater operating temperature difference (over the gas-cooler) when used under transcritical conditions. It is preferred to have transcritical CO2 refriger-ation systems. The drawback of such a system is the extreme operating conditions. A special system must be designed, built and commissioned at the University of Stellenbosch. The system will demand the use or manufacture of unique, special-ised components. Most of the components utilised are extremely expensive and/or difficult to come by, or designed and manufactured specifically for this system. The CO2 system at the University of Stellenbosch is exceptional and stands out from conventional systems in that: - it can operate under both the subcritical and transcritical conditions; - it has multiple expansion units, which can be alternated, giving a total of four different operating configurations; - the system can run with fully automated controllers or as a static system; - the internal heat exchanger can be included or excluded from the system; - all the heat exchangers can run in counter flow or parallel flow; and - The system has multiple testing points, for both temperature and pressure, to give the operator accurate measurements to be used in comparison with design software, etc. Three simulation programs are given that describe the physical system. The first simulation program is a steady-state simulator used to aid in the design of the heat exchangers and the capillary tube. The second simulator is a steady-state program that determines the mass flow rate in the capillary tube. The third simulation is a transient program, programmed to determine the steady-state conditions of a sys-tem, given set initial conditions and a transient start-up.
AFRIKAANSE OPSOMMING: Koolstofdioksied is 'n natuurlike gas wat gebruik word as 'n verkoelingsmiddel so ver terug as die 1850's. Dit is toe hoofsaaklik gebruik omdat dit maklik verkrygbaar en nie giftig is nie. As gevolg van die hoë werksdruk en relatief lae kritiese temperatuur (en hoë kritiese druk) van CO2, is dit geleidelik uitgefaseer en vervang met hidrochloorfluoorkoolstof en chloorfluoorkoolstowwe. Met die ontdekking van die kweekhuiseffek, kweekhuisgasse en osoon-afbrekende gasse, is die Montreal-protokol en die Kyoto-protokol in werking gestel. Hierdie twee protokolle vereis die afname in die gebruik van sekere kweekhuisgasse en die algehele uitsluiting van ander. Die fokus het verskuif na natuurlike gasse wat omgewingsvriendeliker en makliker is om te bekom. Koolstofdioksied is so 'n gas. Maar CO2 het 'n lae kritiese temperatuur en hoë kritiese druk, 33.98 °C en 73.77 bar onderskeidelik. CO2 verkoelingstelsels is meer effektief, het 'n groter koëffisiënt van werksverrigting en het 'n groter bedryfstemperatuur-verskil (oor die gas-verkoeler) wanneer dit gebruik word onder transkritiese toestande. Dit is dus verkieslik om transkritiese CO2 verkoelingstelsels te hê. Die nadeel van so 'n stelsel is die relatief uiterste bedryfstoestande. 'n Spesiale stelsel moet ontwerp word, dikwels met die gebruik of vervaardiging van unieke, hoogs gespesialiseerde komponente. So 'n stelsel is ontwerp vir die Universiteit van Stellenbosch. Die meeste van die komponente wat gebruik is, is baie duur en/of moeilik om te bekom, of is spesifiek ontwerp en vervaardig vir hierdie stelsel. Die CO2-stelsel by die Universiteit van Stellenbosch is uitsonderlik en staan uit bo konvensionele stelsels deurdat: - dit kan funksioneer onder beide subkritiese en transkritiese toestande; - dit verskeie gasuitsettings-eenhede het, wat afgewissel kan word, wat 'n totaal van vier verskillende bedryfskonfigurasies gee; - die stelsel bedryf kan word met volle outomatiese beheerders of as 'n statiese stelsel; - die interne hitte-uitruiler óf in-, óf uitgesluit kan word van die stelsel; - al die hitte-uitruilers bedryf kan word in kontra-vloei of parallelle vloei; en - die stelsel verskeie toetspunte het, vir beide temperatuur en druk, wat die operateur akkurate metings gee om te vergelyk met die ontwerp sagteware, ens., wat gebruik word. Drie gegewe simulasieprogramme beskryf die fisiese stelsel. In een simulasie word 'n bestendige toestand-simulator gebruik om te help met die ontwerp van die hitteruilers en die kapillêre buis. Die tweede simulasie program is 'n bestendige toestands-program wat die algehele vloeitempo in die kapillêre buis bepaal. Die laaste simulasie is 'n vlugtige program, geprogrammeer om die tydelike toestande van 'n stelsel te bepaal, gegewe vasgestelde aanvanklike toestande en 'n kortstondige aanskakeling.
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Thériault, France. "Optimized design of a composite helicopter structure by resin transfer moulding." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99795.
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This research project is partnership project involving industrial, university and government collaborators. The overall objective is to develop and enhance tools for use in Resin Transfer Moulding (RTM) design technology in order to re-design existing metallic parts using composite materials.The specific objective of this work is to present preliminary research findings of the development of an optimized design of a leading edge slat (horizontal stabilizer component) from the Bell Model 407 Helicopter. The results presented here focus on the static stress analysis and the structure design aspects. The findings will serve as a basis for future design optimization as well as further developments in the use of RTM technology in re-designing metallic aeronautic components and can be considered to be "semi-optimized".
This research is based on extensive finite element analysis (FEA) of several composite material configurations, with a comparison made with the original metallic design. Different key criteria of the part design such as ply lay-up, bracket geometry, angle and configuration are tested using FEA technology with the objective of selecting the design which is minimizing stress concentrations. The influence of the modification of model-related parameters was also studied.
Preliminary comparative studies show that the slat configuration with half brackets opened towards the inside with an angle of 70 degrees (angle between the top of the airfoil and the side of the bracket) is the best option according to minimum stress concentration and structural flexibility. This choice is confirmed by other factors such as material savings and ease of processing.
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Haugsbakk, Frida. "Evaluations of how carbon dioxide calculations can be integrated into 3D models at an early design stage for more efficient Life Cycle Assessments on buildings." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230168.
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Life Cycle Assessments on buildings and various environmental certificates are starting to become customary for newbuilding projects in Sweden. Building materials play a big part in a building’s environmental impact. Earlier research indicates that Life Cycle Assessments is not a routine in today’s construction process and it may depend on uncertainties in the methods of quantifying carbon dioxide emissions. This master thesis focuses on how equivalent carbon dioxides, a standard unit to quantify greenhouse gas emissions, of building materials can be integrated with Building Information Modelling. Through meetings with experts in the field, data has been collected. A 3D model of a house was built in order to evaluate both an integration with a cost calculation tool and directly with the 3D model. The results showed how the cost calculation tool works for calculations of equivalent carbon dioxides, early in the pre-construction phase. Difficulties in finding corresponding materials in their database were found and issues with summarizing carbon dioxide data. The integration directly into the 3D model, with visual programming, proved an insert for each materials’ carbon dioxide emissions worked. This allows further updates throughout the building process. It was also possible to import material information to a carbon dioxide calculation tool. This evaluation opened up a possibility to change and update carbon dioxide emissions at an early design stage of a building process with Building Information Modelling along with a need of organizational change due to today's traditional building processes.Livscykelanalyser på byggnader och olika typer av miljöbyggnads-certifieringar blir allt vanligare för nya byggprojekt i Sverige. Materialet i en byggnad spelar en stor roll av hela byggnadens miljöpåverkan. Tidigare forskning indikerar att livscykelanalyser inte är en rutin i dagens byggprocesser vilket kan bero på att osäkerheter i de olika metoderna bakom koldioxidberäkningar. Den här artikeln fokuserar på hur koldioxidekvivalenter av byggnadsmaterial kan bli integrerade med Byggnadsinformationsmodellering. Genom möten med experter i området har datainsamling gjorts för det ändamålet. För att undersöka integreringen byggdes en 3D-modell upp och som senare användes för beräkningar av koldioxidutsläpp i ett kostnads-kalkyleringsverktyg samt undersöka hur en införing av koldioxidekvivalenter direkt i 3D-modellen kunde göras. Resultaten visade hur kostnads-beräkningsverktyget fungerar för beräkningar av koldioxidekvivalenter, tidigt i byggprocessen. Svårigheter i att hitta motsvarande material i kalkyleringsverktygets databas upptäcktes under utvärderingen samt en sammanfattande rapport för beräkningarna. Integrationen direkt i 3D-modellen med visuell programmering visade att en inmatning av koldioxidutsläpp för varje material fungerade vilket möjliggör uppdateringar under hela byggprocessen. Det var också möjligt att importera materialinformation till ett koldioxidberäkningsverktyg. Det öppnar upp möjligheter att ändra och uppdatera koldioxidutsläpp för material tidigt i byggprocessen med hjälp av Byggnadsinformationsmodellering och visar behov av organisationsförändringar på grund av dagens traditionella byggprocess.
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Hass, Joanna R. "Structural characterization of epitaxial graphene on silicon carbide." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26654.
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Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.Committee Co-Chair: Conrad, Edward; Committee Co-Chair: First, Phillip; Committee Member: Carter, Brent; Committee Member: de Heer, Walter; Committee Member: Zangwill, Andrew. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Zerkane, Ali S. H. "Cyclic Loading Behavior of CFRP-Wrapped Non-Ductile Reinforced Concrete Beam-Column Joints." PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3000.
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Use of fiber reinforced polymer (FRP) material has been a good solution for many problems in many fields. FRP is available in different types (carbon and glass) and shapes (sheets, rods, and laminates). Civil engineers have used this material to overcome the weakness of concrete members that may have been caused by substandard design or due to changes in the load distribution or to correct the weakness of concrete structures over time specially those subjected to hostile weather conditions. The attachment of FRP material to concrete surfaces to promote the function of the concrete members within the frame system is called Externally Bonded Fiber Reinforced Polymer Systems. Another common way to use the FRP is called Near Surface Mounted (NSM) whereby the material is inserted into the concrete members through grooves within the concrete cover. Concrete beam-column joints designed and constructed before 1970s were characterized by weak column-strong beam. Lack of transverse reinforcement within the joint reign, hence lack of ductility in the joints, and weak concrete could be one of the main reasons that many concrete buildings failed during earthquakes around the world. A technique was used in the present work to compensate for the lack of transverse reinforcement in the beam-column joint by using the carbon fiber reinforced polymer (CFRP) sheets as an Externally Bonded Fiber Reinforced Polymer System in order to retrofit the joint region, and to transfer the failure to the concrete beams. Six specimens in one third scale were designed, constructed, and tested. The proposed retrofitting technique proved to be very effective in improving the behavior of non-ductile beam-column joints, and to change the final mode of failure. The comparison between beam-column joints before and after retrofitting is presented in this study as exhibited by load versus deflection, load versus CFRP strain, energy dissipation, and ductility.
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BOLDUC, MATTHEW W. "USE OF CARBON FIBER REINFORCED POLYMER PLATES FOR REPAIR OR RETROFIT OF PRESTRESSED AND REINFORCED CONCRETE GIRDERS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1046870127.
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Turano, Stephan Parker. "Carbon Nanotubes chemical vapor deposition synthesis and application in electrochemical double layer supercapacitors /." Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-02242005-094827/unrestricted/turano%5Fstephan%5Fp%5F200505%5Fmast.pdf.
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Thesis (M. S.)--Materials Science and Engineering, Georgia Institute of Technology, 2005.Ready, Jud, Committee Co-Chair ; Carter, Brent, Committee Co-Chair ; Snyder, Bob, Committee Member ; Wang, Zhong Lin, Committee Member. Includes bibliographical references.
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Ukirde, Vaishali. "Trapping of hydrogen in Hf-based high κ dielectric thin films for advanced CMOS applications." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc5114/.
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In recent years, advanced high κ gate dielectrics are under serious consideration to replace SiO2 and SiON in semiconductor industry. Hafnium-based dielectrics such as hafnium oxides, oxynitrides and Hf-based silicates/nitrided silicates are emerging as some of the most promising alternatives to SiO2/SiON gate dielectrics in complementary metal oxide semiconductor (CMOS) devices. Extensive efforts have been taken to understand the effects of hydrogen impurities in semiconductors and its behavior such as incorporation, diffusion, trapping and release with the aim of controlling and using it to optimize the performance of electronic device structures. In this dissertation, a systematic study of hydrogen trapping and the role of carbon impurities in various alternate gate dielectric candidates, HfO2/Si, HfxSi1-xO2/Si, HfON/Si and HfON(C)/Si is presented. It has been shown that processing of high κ dielectrics may lead to some crystallization issues. Rutherford backscattering spectroscopy (RBS) for measuring oxygen deficiencies, elastic recoil detection analysis (ERDA) for quantifying hydrogen and nuclear reaction analysis (NRA) for quantifying carbon, X-ray diffraction (XRD) for measuring degree of crystallinity and X-ray photoelectron spectroscopy (XPS) were used to characterize these thin dielectric materials. ERDA data are used to characterize the evolution of hydrogen during annealing in hydrogen ambient in combination with preprocessing in oxygen and nitrogen.
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Skeika, Tatiane. "Preparação, caracterização e estudos eletroquimicos de eletrodos a base de carbono cerâmico aplicados na determinação de dopamina." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2010. http://tede2.uepg.br/jspui/handle/prefix/2084.
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Previous issue date: 2010-05-11The study of carbon-based ceramic electrodes (CCE) has been significantly increased due to advantages over other electrodes. The CCE features as large surface area, high electrical conductivity and higher mechanical strength, increases their stability and durability. Different parameters of CCE preparation, such as type of precursor, carbon material, catalyst amount, among others, significantly influence the morphological properties and consequently their electrochemical responses. Based on these factors this work presents a 23 factorial design (2 levels and 3 factors) which the factors analyzed were catalyst amount (HCl 12 mol L-1), graphite / precursor ratio, and precursor type (TEOS - tetraethoxysilane and MTMOS - methyltrimetoxysilane). These variables were optimized by analyzing the electrochemical responses obtained in presence of potassium ferrocyanide (at fixed concentration of 1.0 x10-3 mol L-1). The design resulted in a significant third order interaction for anodic peak current values (Ipa), and also to the potential difference (E) between the factors studied which could not be observed using an univariated study. The optimized electrode was modified with ferrocenecarboxylic acid (designated as CCE/Ferrocene) mainly aiming at the increase the sensitivity to the unmodified one. SEM images indicated that the components are homogeneously dispersed in the sample but with some little agglomeration of segregated ferrocene particles. From cyclic voltammetric experiments, it was observed that the CCE/Ferrocene presented a redox pair at Epa = 390.3 mV and Epc = 298.7 mV (E = 91.7 mV), related to the ferrocene/ferrocenium process, since the non- modified CCE did not presented any redox peaks. Studies of the modified electrode in different scan rates resulted in a linear relationship between the anodic peak current values and the scan rate, a characteristic behavior for confined species in the surface electrode. In order to verify the possibility of using the CCE/Ferrocene as an electrochemical sensor, studies in presence of dopamine (DA) were carried out. In this case, it was observed that after DA addition in the electrolyte solution, a considerably increase in the redox currents were observed at same oxidation potential of ferrocene (Epa= 408.0 mV vs Ag/AgCl), different from the observed when using only CCE as electrode material, which the increase in the anodic peak was considerably lower and slightly dislocated to higher positive potential (Epa= 446.1 mV vs Ag/AgCl). Square wave voltammetry (SWV) experiments were evaluated in presence of DA, with optimized parameters. In these conditions, the proposed sensor has shown a linear response range from 0.2 to 1.0 molL-1 with a detection limit of 1.5 mol L-1 to CCE and 0.43 mol L-1 for CCE/Ferrocene. From SWV experiments, it was observed that the AA oxidation at CCE/Ferrocene occurred in a different potential of DA oxidation, with a peak separation of approximately 170.5 mV. Moreover, CCE/Ferrocene did not respond to different AA concentrations indicating that is possible with this electrode determine DA without the interference of AA.
O estudo de eletrodos a base de carbono cerâmico (ECC), tem aumentado significativamente devido às vantagens sobre os demais eletrodos. Os ECC apresentam grande área superficial, alta condutividade elétrica, além de uma maior resistência mecânica, o que aumenta a estabilidade e durabilidade desses eletrodos. Os diferentes parâmetros utilizados na preparação dos ECC, tais como, tipo de precursor, material de carbono, quantidade de catalisador, entre outros, influenciam significativamente nas propriedades morfológicas e consequentemente nas respostas eletroquímicas dos mesmos. Baseando-se nisto, esse trabalho apresenta um planejamento fatorial 23 (2 níveis e 3 fatores) onde os fatores analisados foram a quantidade de catalisador (HCl 12 mol L-1), proporção grafite/precursor, e o tipo de precursor (TEOS - tetraetoxisilano e MTMOS - metiltrimetoxisilano). Tais variáveis foram otimizadas analisando-se as respostas eletroquímicas obtidas na presença de ferrocianeto de potássio (na concentração fixa de 1,0 x10-3 mol L-1). O planejamento resultou numa interação significativa de terceira ordem para os valores de corrente de pico anódico (Ipa) e também para a diferença de potencial (E), entre os fatores estudados o que não poderia ser observado utilizando-se um estudo univariado. O eletrodo otimizado foi modificado com ácido ferrocenocarboxílico (denominado ECC/Ferroceno) visando principalmente o aumento da sensibilidade em relação ao eletrodo não modificado. As imagens de MEV indicaram que os componentes do eletrodo estão homogeneamente dispersos na amostra, mas com pequena aglomeração de partículas segregadas do ferroceno. Através dos estudos de voltametria cíclica (VC), observou-se que o ECC/Ferroceno apresentou um par redox em Epa = 390,3 mV e Epc = 298,7 mV (E = 91,7 mV), relacionados ao processo ferroceno / íon ferroceno já que o ECC sem modificação não apresentou picos redox. O estudo do eletrodo modificado em diferentes velocidades de varredura resultou em uma relação linear entre os valores de corrente de pico anódica e, sendo esse um comportamento típico de espécies confinadas na superfície do eletrodo. Para verificar a possibilidade da aplicação do ECC/Ferroceno como sensor eletroquímico foram realizados estudos na presença de dopamina (DA). Neste caso, foi observado que após a adição de DA na solução eletrolítica, um considerável aumento nas correntes redox foram observados no mesmo potencial de oxidação do ferroceno (Epa = 408,0 mV vs Ag / AgCl), diferente do que foi observado para o ECC. Nesse último caso, a corrente de pico anódica foi consideravelmente mais baixa além do potencial de pico anódico ligeiramente deslocado para regiões mais positivas (Epa = 446,1 V vs Ag / AgCl). A técnica de voltametria de onda quadrada (VOQ) foi aplicada para a determinação de DA, com os parâmetros otimizados. Nessas condições, os sensores propostos apresentaram uma faixa de resposta linear de 0,2 a 1,0 mol L-1 e um limite de detecção de 1,5 mol L-1 para o ECC e 0,43 mol L-1 para o ECC/Ferroceno. A partir dos estudos de VOQ, foi observado ainda que a oxidação de ácido ascórbico (AA) no ECC/Ferroceno ocorreu em um potencial diferente da oxidação de DA, com separação de pico de aproximadamente 170,5 mV. Além disso, o ECC/Ferroceno não apresentou aumento da corrente de pico com a variação da concentração de AA, indicando uma possível aplicação deste eletrodo na determinação de DA sem a interferência do AA.
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Johnson, Ryan William. "Process Development for the Manufacture of an Integrated Dispenser Cathode Assembly Using Laser Chemical Vapor Deposition." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/6978.
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Laser Chemical Vapor Deposition (LCVD) has been shown to have great potential for the manufacture of small, complex, two or three dimensional metal and ceramic parts. One of the most promising applications of the technology is in the fabrication of an integrated dispenser cathode assembly. This application requires the deposition of a boron nitridemolybdenum composite structure. In order to realize this structure, work was done to improve the control and understanding of the LCVD process and to determine experimental conditions conducive to the growth of the required materials. A series of carbon fiber and line deposition studies were used to characterize processshape relationships and study the kinetics of carbon LCVD. These studies provided a foundation for the fabrication of the first high aspect ratio multilayered LCVD wall structures. The kinetics studies enabled the formulation of an advanced computational model in the FLUENT CFD package for studying energy transport, mass and momentum transport, and species transport within a forced flow LCVD environment. The model was applied to two different material systems and used to quantify deposition rates and identify ratelimiting regimes. A computational thermalstructural model was also developed using the ANSYS software package to study the thermal stress state within an LCVD deposit during growth. Georgia Techs LCVD system was modified and used to characterize both boron nitride and molybdenum deposition independently. The focus was on understanding the relations among process parameters and deposit shape. Boron nitride was deposited using a B3N3H6-N2 mixture and growth was characterized by sporadic nucleation followed by rapid bulk growth. Molybdenum was deposited from the MoCl5-H2 system and showed slow, but stable growth. Each material was used to grow both fibers and lines. The fabrication of a boron nitridemolybdenum composite was also demonstrated. In sum, this work served to both advance the general science of Laser Chemical Vapor Deposition and to elucidate the practicality of fabricating ceramicmetal composites using the process.
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Aliahmad, Nojan. "Paper-based lithium-Ion batteries using carbon nanotube-coated wood microfiber current collectors." Thesis, 2013. http://hdl.handle.net/1805/3652.
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Indiana University-Purdue University Indianapolis (IUPUI)The prevalent applications of energy storage devices have incited wide-spread efforts on production of thin, flexible, and light-weight lithium-ion batteries. In this work, lithium-ion batteries using novel flexible paper-based current collectors have been developed. The paper-based current collectors were fabricated from carbon nanotube (CNT)-coated wood microfibers (CNT-microfiber paper). This thesis presents the fabrication of the CNT-microfiber paper using wood microfibers, coating electrode materials, design and assemblies of battery, testing methodologies, and experimental results and analyses. Wood microfibers were coated with carbon nanotubes and poly(3,4-ethylenedioxythiophene) (PEDOT) through an electrostatic layer-by-layer nanoassembely process and formed into a sheet, CNT-microfiber paper. The CNT loading of the fabricated paper was measured 10.1 μg/cm2 subsequently considered. Electrode material solutions were spray-coated on the CNT-microfiber paper to produce electrodes for the half and full-cell devices. The CNT current collector consists of a network structure of cellulose microfibers at the micro-scale, with micro-pores filled with the applied conductive electrode materials reducing the overall internal resistance for the cell. A bending test revealed that the paper-based electrodes, compared to metal ones, incurred fewer damages after 20 bends at an angle of 300o. The surface fractures on the paper-based electrodes were shallow and contained than metallic-based electrodes. The micro-pores in CNT-microfiber paper structure provides better adherence to the active material layer to the substrate and inhibits detachment while bending. Half-cells and full-cells using lithium cobalt oxide (LCO), lithium titanium oxide (LTO), and lithium magnesium oxide (LMO) were fabricated and tested. Coin cell assembly and liquid electrolyte was used. The capacities of half-cells were measured 150 mAh/g with LCO, 158 mAh/g with LTO, and 130 mAh/g with LMO. The capacity of the LTO/LCO full-cell also was measured 126 mAh/g at C/5 rate. The columbic efficiency of the LTO/LCO full-cell was measured 84% for the first charging cycle that increased to 96% after second cycle. The self-discharge test of the full-cell after charging to 2.7 V at C/5 current rate is showed a stable 2 V after 90 hours. The capacities of the developed batteries at lower currents are comparable to the metallic electrode-based devices, however, the capacities were observed to drop at higher currents. This makes the developed paper-based batteries more suitable for low current applications, such as, RFID tags, flexible electronics, bioassays, and displays. The capacities of the batteries at higher current can be improved by enhancing the conductivity of the fibers, which is identified as the future work. Furthermore, fabrication of an all solid state battery using solid electrolyte is also identified as the future work of this project.
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Rajkumar, Chellakannu, and Chellakannu Rajkumar. "Design and Fabrication of Electrodes with Nanoparticles Implanted Carbon Aerogels Nanocomposites for Electrochemical Sensors Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/b75g9j.
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博士國立臺北科技大學
能源與光電材料專班
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奈米技術是一項非常強大的技術，對於許多類型的新型產品的設計和開發具有巨大的潛力，因其在醫療應用，儲能應用，電化學和生物傳感器應用方面具有潛力。然而，製造新型奈米級材料的機會在理論上是無限的，目前大多數合成都涉及已知的方案，這些方案可能對環境或人體健康有潛在危害。另一方面，最近的研究表明碳基奈米複合材料正在以環境健康的方式製造。然而，當用於電催化應用時，仍然傳統的碳（石墨，石墨烯，還原氧化石墨烯和多壁碳奈米管）奈米複合材料具有一些關鍵限制。因此，我們有興趣通過替代碳基奈米複合材料來解決這個問題。本研究工作的總體範圍是設計和開發一種碳氣凝膠及其基於奈米複合材料的環保型生物應用電化學傳感器，並將應用所得結果與傳統碳基奈米複合材料進行對比。在這裡，通過不同的方法研究製造電極。最初，我們使用生物聚合物（殼聚醣，CS）支持的碳氣凝膠（CA）奈米複合物修飾的絲網印刷碳電極（SPCE），展示了用於異煙肼（IZ）的簡單且超靈敏的電化學感測器。 CA / CS複合材料的相互連接的介孔結構提供了大孔隙率（VTot = 0.688cm3g-1）的大表面積（SBET = 461m2g-1）。此外，由於存在許多活性位點（-C = O，-NH，-NH2，-OH），CS / CA修飾的SPCE表現出增強的電催化活性。此外，在可能的干擾分子存在下，CS / CA修飾的SPCE對於檢測IZ表現出良好的穩定性和選擇性。此外，電化學感測器由碳氣凝膠支撐的金槲皮素（Au @ QCR-CAs）奈米複合材料製成，用於同時測定肼（HZ）和羥胺（HA），檢測限低，濃度範圍廣。從Au @ QCR-CAs修飾的SPCE可以看出，由於CAs具有優異的電導率和Au @ QCR奈米粒子的出色催化活性，可以很好地分離出HZ和HA的氧化峰和峰電流。此外，我們通過簡便的微波還原路線開發了支撐在多孔碳氣凝膠（Pd / CA）上的高度穩定的鈀奈米顆粒（Pd NP）。發現Pd奈米顆粒均勻地分散在具有大表面積（851.8 m2 g-1）和孔體積（3.021 cm3 g-1）的多孔碳基質中。發現Pd / CA複合物具有非凡的電催化活性和優異的同時檢測多巴胺（DA）和褪黑激素（ML）的選擇性。在此之前，我們設計了一種簡便的方法，通過使用摻入了鈀 - 釕奈米粒子的碳氣凝膠（Pd-Ru / CA）來進行日落黃（SY）的電化學測定和催化降解。採用溶膠 - 凝膠聚合法製備了Pd-Ru / CA奈米複合材料，採用蒸發誘導自組裝（EISA）方法製備了改性絲網印刷碳電極（SPCE），該電極具有良好的電化學檢測和催化降解SY，甚至在實際樣品中也超過了傳統的HPLC方法。計算了各種動力學參數，如電荷轉移係數，轉移質子數，轉移電子數和標準非均勻速率常數等，並對眾多實驗參數進行了優化。通過CV，計時電流法（i-t）和DPV方法對整個製造的碳氣凝膠和碳氣凝膠奈米複合材料電極進行了徹底的評估。通過這種探索，所提出的電極分別具有更高的穩定性，高靈敏度，良好的線性範圍和檢測極限，具有較好的電催化行為。
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"Fabrication of three dimensional nanostructured cadmium selenide and its potential applications in sensing of deoxyribonucleic acid." 2009. http://library.cuhk.edu.hk/record=b5894109.
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Ho, Yee Man Martina = 硒化鎘三維納米結構之製作及其感應脫氧核糖核酸之應用潛能 / 何綺雯.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references.
Abstract also in Chinese.
Ho, Yee Man Martina = Xi hua ge san wei na mi jie gou zhi zhi zuo ji qi gan ying tuo yang he tang he suan zhi ying yong qian neng / He Qiwen.
Chapter Chapter 1 --- Introduction
Chapter 1 --- Photovoltaic properties of CdSe --- p.1
Chapter 1.1 --- Quantum size effect --- p.1
Chapter 1.2 --- Synthesis of CdSe nanostructures --- p.3
Chapter 1.3 --- Electrochemical sensing of CdSe nanostructures --- p.4
Chapter 1.3.1 --- Surface passivation and functionalization of CdSe nanostructures --- p.5
Chapter 1.4 --- Electronic properties of nanocrystalline semiconductor electrode --- p.6
Chapter 1.4.1 --- Band alignment --- p.6
Chapter 1.4.2 --- Interfacial charge transfer process --- p.9
Chapter 1.4.3 --- Surface traps and adsorbed molecules --- p.10
Chapter 1.4.4 --- DNA molecules as a capping group --- p.11
Chapter 1.5 --- Literatures review in DNA sensing --- p.12
Chapter 1.6 --- Present study --- p.14
Chapter 1.6.1 --- Objective --- p.14
Chapter 1.6.2 --- General methodology --- p.15
Chapter Chapter 2 --- Experimental
Chapter 2.1 --- Introduction into the instrumentation of this project --- p.21
Chapter 2.2 --- CHI Electrochemical workstation --- p.22
Chapter 2.2.1 --- Linear sweep voltammetry --- p.24
Chapter 2.2.2 --- Cyclic voltammetry --- p.24
Chapter 2.2.3 --- Multiple potential step --- p.25
Chapter 2.3 --- CEM Microwave-assisted chemical synthesizer --- p.27
Chapter 3.1 --- Morphological examination by scanning electron microscopy --- p.28
Chapter 3.2 --- Elemental analysis by energy dispersive x-ray spectroscopy --- p.30
Chapter 3.3 --- Crystal structure analysis by x-ray diffraction --- p.31
Chapter 3.4 --- Surface compositional analysis by x-ray photoelectron spectroscopy --- p.32
Chapter 3.5 --- Transmission electron microscopy --- p.34
Chapter Chapter 3 --- Synthesis of 3D nanostructured CdSe multipod electrodes
Chapter 3.1 --- Introduction into the synthesis of CdSe MP electrode --- p.35
Chapter 3.2 --- Recipe for the synthesis of CdSe NPs --- p.36
Chapter 3.3 --- The synthesis of CdSe MPs --- p.37
Chapter 3.3.1 --- Tuning the experimental parameters: Reaction temperature --- p.37
Chapter 3.3.2 --- Tuning the experimental parameters: Reaction hold time --- p.46
Chapter 3.3.3 --- Tuning in experimental parameters: Precursor molar ratio --- p.50
Chapter 3.4 --- The fabrication of MP CdSe on a conductive substrate --- p.54
Chapter 3.4.1 --- The electrodeposition of CdSe thin films on ITO/glass substrates --- p.55
Chapter 3.4.2 --- The growth of CdSe MPs on CdSe/ ITO/glass --- p.57
Chapter 3.5 --- The characterization of MP CdSe electrode --- p.57
Chapter Chapter 4 --- Electrical and opto-electric characteristics of CdSe MP electrodes and their applications as platforms for the DNA recognition
Chapter 4.1 --- Introduction to the property characterization of CdSe MP electrodes --- p.62
Chapter 4.2 --- DNA surface attachment --- p.64
Chapter 4.2.1 --- Mechanism of DNA surface anchoring --- p.65
Chapter 4.3 --- I-V characterization in PBS --- p.69
Chapter 4.3.1 --- Experimental procedures of the I-V tests in PBS --- p.70
Chapter 4.3.2 --- Results and discussions of I-V tests in PBS --- p.72
Chapter 4.3.2.1 --- Exercising as-prepared CdSe MP electrode --- p.74
Chapter 4.3.2.2 --- I-V characteristics of CdSe MP electrodes before and after ssDNA attachment --- p.75
Chapter 4.3.2.3 --- I-V characteristics of CdSe MP electrodes before and after the dsDNA attachment --- p.76
Chapter 4.3.2.4 --- "Photo-response of bare CdSe MP, ssDNA/CdSe MP and dsDNA/CdSe electrodes" --- p.77
Chapter 4.4 --- "Photovoltaic I-V measurement in I3""/I"" redox electrolyte" --- p.79
Chapter 4.4.1 --- Experimental procedures --- p.79
Chapter 4.4.2 --- Results and discussions --- p.80
Chapter 4.5 --- Possible application implied by the results --- p.88
Chapter 4.5.1 --- DNA base pair mismatch identification --- p.91
Chapter 4.5.2 --- Field-assisted DNA hybridization acceleration process --- p.92
Chapter Chapter 5 --- Conclusions
Chapter 5.1 --- Conclusions --- p.95
36
Chen, Yen-shen, and 陳彥深. "Research on Design Strategies for Building Construction to Reduce the Carbon Dioxide Emission." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/71957172936794064439.
Full textAbstract:
碩士國立臺灣科技大學
建築系
97
It is well known that emission of the greenhouse gases lead to greenhouse effect, which is the most important factor of the global warming phenomenon.And carbon dioxide has contributed 55 percent proportion of the huge impact of greenhouse gases which caused global warming. Due to the result of human activities, carbon dioxide, mainly from the combustion of oil, coal, these kinds of petrochemical raw materials, and architecture which relies on energy-driven is the main industry which caused the emissions of it. In view of this, this study was to set up a building strategy of low-carbon emission for life-cycle phases of the construction process of the carbon dioxide output, and apply this strategy to demonstrate the operation of the case.We expect to use this research as a reference for construction planning, designing, promotion of sustainable building concepts, and help the environmental protection efforts. The relationship between Architecture and carbon dioxide emissions could be analyzed from environmental (non-construction) part and building part. And building Part can also be subdivided into energy, water and material these three areas, to go to the bottom of the carbon dioxide output. With the limitation of the time and resource constraints, the scope of this study will only talk about the carbon reducing strategy for the "substance" part of the construction. To carry out this study with the main contents are as follows: �P Chapter II collects, aggregates the literatures and practical cases relating to low carbon dioxide emission strategy, and analysis, summarized in a feasible way to reduce carbon, as a basis for follow-up operation. �P Chapter III divides the life cycle of the construction area into "materials capturing to construction", "repair and removal" and "recycling and disposal" three phase process, and put forward: 1. The application of information assessment tools, 2. Materials re-using, 3. Reducing, 4. Zero-pollution for emissions and materials, 5. Maintenance and removal information providing, 6. Re-using, 7. Detachable node, 8. Warranty, 9. Durability, 10. Zero-pollution for consumables maintenance, 11. Circulation and disposal system collocating, 12. Recycling, 13. Zero-pollution for recycle and waste material, with a total of 13 building strategy for low carbon dioxide emissions, and we will state each of them with the theoretical basis and application. �P Chapter IV applies this low carbon dioxide emissions strategy for the architectural structure, and carries out the operation of a model case, also analyzing and reviewing the overall designed results of it. Constitutive method and the materials for use are extremely diversified, and with the advancing technology today, modern architecture becomes increasingly large and complex.Therefore, if we can use information technology to develop the carbon dioxide evaluation of the various construction methods for the construction life cycle, also to build a more comprehensive supervision and building materials resume system. It will be more comprehensive to reduce the production of carbon dioxide from the construction life cycle for constructing a full range of Green buildings.
37
Zhu, Ruixing. "Characterization of Positive Electrodes in Sodium-Metal Chloride Batteries." Thesis, 2016. https://doi.org/10.7916/D82R3RGR.
Full textAbstract:
The high-performance sodium metal chloride battery has garnered significant interest in the past decade due to its multiple advantages such as high energy density, deep discharge cycling ability, high safety level, 100% coulombic efficiency, and a broad ambient-temperature operating range. Current development of the sodium-metal chloride batteries is focused on improving its performance and cycling life.
This work investigates micro-scale mass transfer and kinetic parameters, which is related to cell performance, for building a complete model. In a typical commercial sodium metal chloride cell, there is mass transfer and conduction throughout the thick positive electrode. The electrode materials participate in redox reactions neither homogeneously nor simultaneously. Therefore, a much thinner positive electrode is introduced in this work in order to remove added macro-scale effects in the electrode from the measurement. Therefore, the number of parameters needed to describe the data was reduced because the experimental design minimizes spatial variations within the cell.
Chapter 2 discusses the impact of iron addition to a sodium nickel-chloride cell by investigating ionic transport within the metal chloride phase. The electrochemical performance of a sodium mixed-metal (Ni, Fe) halide cell is characterized for different cathode compositions and at different rates. Charge/discharge data are characterized by a smaller nickel-voltage plateau during discharge than during charge, indicating that some of the NiCl₂ reduces at cell potentials nominally associated with the iron plateau. One means of describing the difference between charge and discharge is to consider transport processes within the mixed NiCl₂/FeCl₂ solid phase. A one-dimensional model has been used to simulate the ionic transport within the (Ni,Fe)Cl₂ phase; the transport model predicts the ratio of discharge to charge iron plateaus reasonably well for most rates and compositions.
In order to further investigate complex dynamic behavior of the open-circuit potential (OCP) and galvanic interactions in an iron-doped sodium nickel-chloride cell, a GITT (Galvanostatic Intermittent Titration Technique) method is used in Chapter 3. The response to open-circuit interrupts of porous mixed iron-nickel cathodes has been characterized as a function of state of charge (SOC) for different iron loadings and different charge and discharge rates. After discharge, OCP can evolve in time from the iron plateau to the nickel plateau, and this behavior can be explained by galvanic interactions between iron metal and Ni²⁺. Characteristic times of the OCP transients depend on SOC and can be large. When the OCP has converged on a steady state during discharge, its value may provide an estimate of the mole fraction of NiCl₂ at the interface of the triclinic (Ni,Fe)Cl₂ film that resulted from metal oxidation.
Sulfur-containing additives were shown to have dramatic impact on cell resistance and performance. In Chapter 4, the electrochemistry of iron sulfide in nickel/iron porous electrodes in molten sodium tetrachloroaluminate electrolyte was investigated. With the addition of FeS to the electrolyte, results indicate the formation of nickel sulfide species on the metal electrode and an increasing discharge capacity with increasing amount of iron sulfide. The cathode with highest sulfide content appears to be highly resistive. Galvanostatic interrupt experiments shows complex dynamic behavior of sulfide-iron-NiCl₂ galvanic interactions.
With a goal of extending knowledge of kinetic and mass transfer parameters for understanding mass transfer, Chapter 5 discusses the performance of nickel/iron cells for a broader range of temperature, composition and current. The experiments were tested at different temperatures. Also, three granule compositions with different iron levels are tested at four different current rates. The data from this study can be for use in a complete model of the sodium-nickel/iron chloride cell and in the optimization of the electrode.
In the previous chapters, a thinner positive electrode is used in order to remove the effects of macro-scale mass transfer. Chapter 6 discusses the impact of thickness of the cathode on the mass macro-scale transfer and conduction within the metal chloride and metal phase. The goal is to improve modeling of tortuosity as a function of state of charge because transport is important in real systems, and modeling ohmic resistance, for example, can be challenging.
38
Spanos, Constantine. "Investigating the efficacy of inverse-charging of lead-acid battery electrodes for cycle life and specific energy improvement." Thesis, 2017. https://doi.org/10.7916/D8PC371H.
Full textAbstract:
Although competitive today, traditional PbA (<1500 cycles) and advanced lead-acid batteries (ALAB) (>4000 cycles) will not be able to compete with lithium and flow batteries by 2020. To compete with novel zinc, lithium and flow batteries, the PbA chemistry needs to achieve significant performance improvements, primarily through sustainable increases to specific energy (Wh/kg), while not negatively impacting cycle life.
Inverse charging has been examined for its potential in improving PbA cycle life as a battery maintenance procedure, and as a potential technique for improving electrode specific capacity (mAh/kg) during battery manufacturing and formation. A thorough levelized cost of energy (LCOE) shows that for traditional PbA batteries with cycle lives <2000, inverse charging as a maintenance strategy (to increase cycle life) improves battery economics. Inverse charging to increase cycle life for ALAB systems (>4000 cycle life) was proven to worsen battery economics, as additional costs of capital and maintenance fail to outweigh savings achieved through reductions in replacement cost. On the other hand, inverse charging employed as a manufacturing practice to increase specific energy dramatically reduces the cost of the PbA and ALAB systems, ensuring future cost competitiveness. Inverse charging as a maintenance strategy should be restricted to devices with <2000 cycles and to projects with long project lives (20 years) that require frequent replacement. Inverse charging as a manufacturing strategy (to increase specific energy) is highly preferable in all instances.
When successful, inverse charging increases the specific capacity and active material utilization of studied battery electrodes significantly. Successful inverse charging of battery electrodes and pure lead rods show improvements in discharge capacities over a range of discharge rates with negligible impact to coulombic and energy efficiency values. The extent of success, however, depends on several important variables. Thorough examination of inverse charging on Pb rods and porous battery electrodes illustrates the importance of the degree of prior electrode sulfation and obstruction of transport of H₂SO₄. Other important factors include the composition of electrode grid alloys, the peak oxidation voltage applied to the negative electrode during inverse charging, initial particle sizes, and electrolyte additives.
Significant challenges to inverse charging exist. For heavily sulfated batteries and lead metals, impeded electrolyte transport results in excessive internal pore pH increases, creating semipermeable membranes through an electrode hydration mechanism, resulting in dramatic inverse charging failure. Additionally, impedance, voltage, x-ray and BET data hint that post-inverse charging, agglomeration of finely divided Pb and PbSO₄ particles occurs, coupled with negative electrode conductive pathway destruction. As such, the influence of expander materials and nucleation additives should be investigated to better prevent sulfation failure, and to better control the nucleation and growth of lead and lead sulfate structures during inverse charging.
Cycle life studies on flooded lead antimony batteries subjected to periodic inverse charging illustrate that inverse charging is highly successful on all batteries independent of states-of-health. Batteries with poor states-of-health (discharge capacities <15% of initial values) experienced almost perfect discharge capacity restoration post-inverse charging. Traditional methods of extending cycle life (i.e. prolonged overcharging techniques) were demonstrated to be inadequate at appreciably regenerating battery capacities, providing only marginal increases.
The benefits of inverse charging, however, are met with significant challenges to battery redesign. Temporary antimony poisoning effects lead to declines in round-trip-efficiency for batteries with antimony-based positive plates. Tin dissolution results in diminished grid to active material conductivity and reduced capacity for batteries with tin-based positives. For the negative electrode, Brunauer–Emmett–Teller (BET) surface area and x-ray measurements indicate that although large PbSO₄ crystals are oxidized during inverse charging, creating extensive micropore networks during conversion from Pb to PbO₂, surface area and capacity gains are lost during reconversion back to sponge lead due to uncontrolled nucleation and particle fusion. Additionally, active material shedding of the positive and negative electrodes is observed to spike during and after inverse charging. Negative electrode active material suffers excessive degradation and loss of cohesion, particularly for electrodes with small initial particle feature sizes, resulting in a loss of structure upon completion of the technique. Positive electrode composition changes to weakly interconnected b-PbO₂, dramatically increasing electrode capacity while simultaneously accelerating electrode failure through shedding. Loss of particle cohesion in both electrodes promotes excessive shedding and sludging, creating intra-cellular short-circuits. In addition, inverse charging aggravates grid growth, promoting inter-cellular short-circuiting by creating pathways for cell-to-cell electrolyte contact upon seal destruction in current monoblock designs.
39
"CNT-based thermal convective accelerometer." 2009. http://library.cuhk.edu.hk/record=b5894128.
Full textAbstract:
Zhang, Yu.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 55-60).
Abstract also in Chinese.
Abstract --- p.i
Acknowledgement --- p.iii
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Background --- p.1
Chapter 1.2 --- Aim of Research --- p.2
Chapter 1.3 --- Thesis Organization --- p.3
Chapter 2 --- Literature Review --- p.4
Chapter 2.1 --- Carbon Nanotubes in MEMS Devices --- p.4
Chapter 2.1.1 --- CNT Integration and CNT sensors --- p.4
Chapter 2.1.2 --- Prior Work in CMNS --- p.6
Chapter 2.2 --- Overview of Motion Sensors --- p.7
Chapter 2.2.1 --- Technology Overview --- p.7
Chapter 2.2.2 --- Categories and Working Principles --- p.9
Chapter 2.2.3 --- Application --- p.13
Chapter 2.3 --- Thermal Convective Motion Sensors --- p.14
Chapter 2.3.1 --- Micro Thermal Flow Sensors --- p.15
Chapter 2.3.2 --- Research on Thermal Convective Motion Sensors --- p.17
Chapter 2.3.3 --- Working Principle and Performances --- p.20
Chapter 3 --- Design and Setup --- p.25
Chapter 3.1 --- Methodology --- p.25
Chapter 3.1.1 --- Research Method --- p.25
Chapter 3.1.2 --- Critical Questions --- p.26
Chapter 3.2 --- Sensor Chip Design and Fabrication --- p.27
Chapter 3.2.1 --- Sensor Chip Mask Design --- p.27
Chapter 3.2.2 --- Fabrication of Sensor Chip --- p.29
Chapter 3.3 --- Sensor Prototyping --- p.30
Chapter 3.3.1 --- CNT Deposition --- p.30
Chapter 3.3.2 --- Sensor Building --- p.32
Chapter 3.4 --- Setup of Experiment --- p.34
Chapter 3.4.1 --- Source and Measure --- p.34
Chapter 3.4.2 --- Acceleration Production --- p.35
Chapter 4 --- Experiments and Results --- p.39
Chapter 4.1 --- Hypotheses Verification --- p.39
Chapter 4.1.1 --- Thermal Detection Using CNT --- p.39
Chapter 4.1.2 --- Local Heating & Sensing --- p.40
Chapter 4.2 --- Tilting Test --- p.42
Chapter 4.2.1 --- Test Result --- p.42
Chapter 4.2.2 --- Result Discussions --- p.43
Chapter 4.3 --- Vibration Test --- p.45
Chapter 4.3.1 --- Test Result --- p.45
Chapter 4.3.2 --- Result Discussions --- p.52
Chapter 5 --- Conclusion --- p.53
Bibliography --- p.55
40
Kim, Daejong. "Design and fabrication of sub-millimeter scale gas bearings with tungsten-containing diamond like carbon coatings." Thesis, 2004. http://hdl.handle.net/2152/2039.
Full text
41
"Extreme-low power NaOCl sensor using EG-CNTs as the sensing element." 2009. http://library.cuhk.edu.hk/record=b5894132.
Full textAbstract:
Yang, Li.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 67-72).
Abstract also in Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Background and Motivation --- p.1
Chapter 1.2 --- Objectives --- p.2
Chapter 1.3 --- Contributions --- p.2
Chapter 1.4 --- Organization of the Dissertation --- p.3
Chapter 2 --- Carbon Nanotubes as Sensing Elements --- p.4
Chapter 2.1 --- Introduction --- p.4
Chapter 2.2 --- Introduction to Carbon Nanotubes --- p.4
Chapter 2.3 --- Chemical Sensor Applications --- p.6
Chapter 2.3.1 --- Semiconducting Sensors --- p.7
Chapter 2.3.2 --- Dielectric Sensors --- p.8
Chapter 2.3.3 --- Adsorption Based Sensors --- p.9
Chapter 2.4 --- Dielectrophoresis of CNTs --- p.9
Chapter 2.4.1 --- Theory and Methodology --- p.10
Chapter 2.4.2 --- Basic CNTs Sensor Fabrication Process Using DEP Force --- p.13
Chapter 2.4.3 --- Electronic-Grade Carbon Nanotubes --- p.13
Chapter 2.4.4 --- Simulation --- p.14
Chapter 2.5 --- Photodesorption Phenomenon --- p.16
Chapter 2.5.1 --- Chemical Desorption Process Induced by UV Illumination --- p.16
Chapter 2.6 --- Summary --- p.19
Chapter 3 --- Design of NaOCl Sensors Based on EG-CNTs in Microfluidic System --- p.20
Chapter 3.1 --- Introduction --- p.20
Chapter 3.2 --- Chemical --- p.20
Chapter 3.2.1 --- Introduction to Chemical Properties and Reactions --- p.21
Chapter 3.2.2 --- Reagents --- p.23
Chapter 3.3 --- Methods for Chemical Detection --- p.23
Chapter 3.3.1 --- Hypochlorite Detection --- p.23
Chapter 3.3.2 --- Chlorine Gas Detection --- p.24
Chapter 3.4 --- Design and Fabrication --- p.26
Chapter 3.4.1 --- Sodium Hypochlorite Sensor Using Microfluidic System --- p.26
Chapter 3.4.2 --- Modified Design For Indirect Detection to Chlorine Gas --- p.29
Chapter 3.5 --- Equipments --- p.30
Chapter 3.5.1 --- Source Meter --- p.30
Chapter 3.5.2 --- Pneumatic Pump --- p.31
Chapter 3.5.3 --- UV Illumination Devices --- p.31
Chapter 3.5.4 --- Experimental Setup --- p.32
Chapter 3.6 --- Summary --- p.34
Chapter 4 --- Results --- p.35
Chapter 4.1 --- Introduction --- p.35
Chapter 4.2 --- Processes of the Experiments --- p.35
Chapter 4.2.1 --- Response to Static Solution --- p.35
Chapter 4.2.2 --- Response to Fluid Flow --- p.36
Chapter 4.2.3 --- Response to Gas --- p.36
Chapter 4.3 --- Noise and Accuracy --- p.37
Chapter 4.4 --- I-V Characteristics --- p.38
Chapter 4.4.1 --- EG-CNTs Sensor --- p.38
Chapter 4.4.2 --- Variation Under UV Illumination --- p.39
Chapter 4.5 --- Responses to Sodium Hypochlorite Solution --- p.41
Chapter 4.5.1 --- Typical Responses --- p.41
Chapter 4.5.2 --- Selectivity --- p.44
Chapter 4.5.3 --- Sensitivity --- p.45
Chapter 4.5.4 --- Effect of Injection Flow Rate on Sensor Performance --- p.50
Chapter 4.5.5 --- Effect of Volume on Sensor Performance --- p.51
Chapter 4.5.6 --- Continuous Detection --- p.54
Chapter 4.5.7 --- Operating Power Limit --- p.57
Chapter 4.6 --- Response to Chlorine Gas by Modified Design --- p.59
Chapter 4.7 --- Desorption Induced by UV Illumination --- p.60
Chapter 4.8 --- Summary --- p.63
Chapter 5 --- Conclusion --- p.64
Chapter 5.1 --- Future Work --- p.65
Chapter 5.1.1 --- Selectivity --- p.65
Chapter 5.1.2 --- Gaseous Chlorine Detection --- p.66
Chapter 5.1.3 --- UV-LED Induced Desorption --- p.66
Chapter 5.2 --- Concluding Remarks --- p.66
Bibliography --- p.67
42
"Fabrication and characterization of a porous CuO/CeO₂/Al₂O₃ biomorphic compound." 2009. http://library.cuhk.edu.hk/record=b5894162.
Full textAbstract:
Chiu, Ka Lok = 多孔生物遺態氧化銅/氧化鈰/氧化鋁之複合物料的製作及其定性分析 / 趙家樂.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references.
Abstract also in Chinese.
Chiu, Ka Lok = Duo kong sheng wu yi tai yang hua tong/yang hua shi/yang hua lu zhi fu he wu liao de zhi zuo ji qi ding xing fen xi / Zhao Jiale.
Abstract --- p.i
摘要 --- p.iii
Acknowledgment --- p.v
Table of contents --- p.vi
List of table captions --- p.x
List of figure captions --- p.xi
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Carbon monoxide (CO) --- p.1
Chapter 1.2 --- Production of hydrogen from methanol for fuel cell --- p.2
Chapter 1.3 --- Catalysts for CO oxidation and methanol reforming --- p.5
Chapter 1.4 --- Copper-based catalysts --- p.6
Chapter 1.5 --- Mechanisms in the catalytic processes --- p.7
Chapter 1.6 --- Synthesis of Cu-based catalysts --- p.10
Chapter 1.7 --- Potential applications of the biomorphic CuO/CeO2/Al2O3 catalyst --- p.11
Chapter 1.8 --- Objectives and the thesis layout --- p.12
Chapter 1.9 --- References --- p.13
Chapter Chapter 2 --- Methods and Instrumentation --- p.16
Chapter 2.1 --- Sample preparations --- p.16
Chapter 2.1.1 --- Syntheses of the biomorphic samples --- p.16
Chapter 2.1.2 --- Syntheses of the control samples (R1 and R2) --- p.17
Chapter 2.2 --- Characterization --- p.18
Chapter 2.2.1 --- Scanning electron microscope (SEM) --- p.18
Chapter 2.2.2 --- Transmission electron microscopy (TEM) --- p.19
Chapter 2.2.3 --- X-ray powder diffractometry (XRD) --- p.20
Chapter 2.2.4 --- Fourier transform infrared (FTIR) spectroscopy --- p.21
Chapter 2.2.5 --- Raman scattering (RS) spectroscopy --- p.22
Chapter 2.2.6 --- Differential thermal analysis (DTA) --- p.22
Chapter 2.2.7 --- Thermogravimetric analysis (TGA) --- p.23
Chapter 2.2.8 --- Gas sorption surface analysis (GSSA) --- p.24
Chapter 2.3 --- Catalytic activity --- p.25
Chapter 2.3.1 --- CO oxidation --- p.25
Chapter 2.3.2 --- Partial oxidation of methanol (POMe) --- p.27
Chapter 2.3.3 --- Steam reforming of methanol (SRMe) --- p.28
Chapter 2.4 --- References --- p.29
Chapter Chapter 3 --- "Results, discussions and characterization" --- p.31
Chapter 3.1 --- Biomorphic samples --- p.31
Chapter 3.1.1 --- Macrostructures --- p.31
Chapter 3.1.2 --- SEM and TEM results --- p.32
Chapter 3.1.3 --- XRD analysis and chemical compositions --- p.35
Chapter 3.1.4 --- RS results --- p.41
Chapter 3.1.5 --- FTIR results --- p.44
Chapter 3.1.6 --- Thermal property --- p.46
Chapter 3.1.7 --- Porosity analysis --- p.48
Chapter 3.2 --- Control sample R1 --- p.52
Chapter 3.2.1 --- Microstructures --- p.52
Chapter 3.2.2 --- Surface area and porosity --- p.55
Chapter 3.2.3 --- Thermal property --- p.56
Chapter 3.2.4 --- "XRD, FTIR and RS results" --- p.58
Chapter 3.3 --- Control sample R2 --- p.60
Chapter 3.3.1 --- Microstructures --- p.60
Chapter 3.3.2 --- Surface area and porosity --- p.61
Chapter 3.3.3 --- "XRD, FTIR and RS results" --- p.62
Chapter 3.3.4 --- Thermal property --- p.63
Chapter 3.4 --- Formation mechanisms of the biomorphic samples --- p.64
Chapter 3.5 --- Impacts of the Cu/Ce/Al ratios on the CuO dispersion --- p.66
Chapter 3.6 --- Cotton biotemplate --- p.66
Chapter 3.7 --- Formation mechanisms of R1 and R2 --- p.67
Chapter 3.8 --- References --- p.69
Chapter Chapter 4 --- Evaluations of Catalytic Activities --- p.71
Chapter 4.1 --- CO oxidation --- p.71
Chapter 4.2 --- POMe --- p.79
Chapter 4.3 --- SRMe --- p.91
Chapter 4.4 --- Physical properties of the biomorphic samples before and after the reactions --- p.97
Chapter 4.5 --- Structure of the sample and its catalytic performance --- p.102
Chapter 4.6 --- CuO dispersion and the catalytic performance --- p.103
Chapter 4.7 --- Al2O3 and CeO2 and the catalytic performance --- p.105
Chapter 4.8 --- Catalytic performance of the biomorphic samples and R2 --- p.108
Chapter 4.9 --- References --- p.109
Chapter Chapter 5 --- Conclusions and suggestions for further studies --- p.110
Chapter 5.1 --- Conclusions --- p.110
Chapter 5.2 --- Future works --- p.112
Chapter 5.3 --- References --- p.114
43
Kelly, David Quest. "Metal-oxide-semiconductor devices based on epitaxial germanium-carbon layers grown directly on silicon substrates by ultra-high-vacuum chemical vapor deposition." Thesis, 2006. http://hdl.handle.net/2152/2903.
Full text
44
"Experimental investigation on activation power requirement for CNTs-based sensors." 2009. http://library.cuhk.edu.hk/record=b5894131.
Full textAbstract:
Ouyang, Mengxing.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 83-88).
Abstracts in English and Chinese.
Chapter 1. --- Introduction --- p.1
Chapter 1.1 --- Background and Motivation --- p.1
Chapter 1.2 --- Objectives --- p.2
Chapter 1.3 --- Contributions --- p.3
Chapter 1.4 --- Organization of the Dissertation --- p.3
Chapter 2. --- CNTs and Their Application as Sensors --- p.5
Chapter 2.1 --- Introduction to CNTs --- p.5
Chapter 2.2 --- CNTs Based Sensors --- p.8
Chapter 3. --- F-CNTs Based Ethanol Sensors --- p.10
Chapter 3.1 --- Introduction --- p.10
Chapter 3.1.1 --- Carbon Nanotube Alcohol Sensors --- p.11
Chapter 3.1.2 --- CNTs Sensor Configuration --- p.12
Chapter 3.1.3 --- Activation of CNTs Sensor --- p.13
Chapter 3.1.4 --- Functionalization of CNTs --- p.14
Chapter 3.2 --- Fabrication of F-CNTs Based Ethanol Sensors --- p.16
Chapter 3.2.1. --- Fabrication of f-CNTs --- p.16
Chapter 3.2.2. --- Fabrication of Sensing Elements by DEP Manipulation --- p.17
Chapter 3.2.3. --- Experimental Setup --- p.19
Chapter 3.2.4. --- Mechanism of Ethanol Sensor --- p.20
Chapter 3.3 --- Characterization of F-CNTs Based Ethanol Sensors --- p.21
Chapter 3.3.1. --- I-V Characteristics --- p.21
Chapter 3.3.2. --- Thermal Sensitivity --- p.22
Chapter 3.3.3. --- Stability --- p.23
Chapter 3.3.4. --- FFT and Spectral Analysis --- p.23
Chapter 3.4 --- Performance of F-CNTs Based Ethanol Sensors --- p.26
Chapter 3.4.1. --- Typical Response --- p.26
Chapter 3.4.2. --- Selectivity --- p.27
Chapter 3.4.3. --- Towards Low Concentration --- p.28
Chapter 3.4.4. --- Towards Realistic application --- p.29
Chapter 3.5 --- Constant Power Configuration --- p.32
Chapter 3.5.1. --- Constant Power Circuit for Ethanol Detection --- p.32
Chapter 3.5.2. --- Sensor Response versus Power --- p.35
Chapter 3.5.3. --- Responsivity --- p.37
Chapter 3.5.4. --- Noise --- p.38
Chapter 3.5.5. --- Sensitivity --- p.39
Chapter 3.5.6. --- Dynamic Response --- p.41
Chapter 3.6 --- Comparison between F-MWNTs and MWNTs --- p.43
Chapter 3.6.1. --- I-V Characteristics --- p.43
Chapter 3.6.2. --- Cycling Response --- p.44
Chapter 3.6.3. --- Dynamic Response --- p.46
Chapter 3.6.4. --- Sensor Performance under Different Power --- p.48
Chapter 3.7 --- Summary --- p.53
Chapter 4. --- EG-CNTs Based Flow Sensors --- p.55
Chapter 4.1 --- Introduction to CNTs Flow Sensors --- p.55
Chapter 4.2 --- EG-CNTs and Their Applications --- p.56
Chapter 4.2.1 --- Intro to EG-CNTs Sensor --- p.56
Chapter 4.2.2 --- Fabrication of EG-CNTs Sensor --- p.57
Chapter 4.2.3 --- Experimental Characterization --- p.59
Chapter 4.2.3.1. --- I-V Characteristics --- p.59
Chapter 4.2.3.2. --- Thermal Sensitivity --- p.61
Chapter 4.2.3.3. --- Humidity responsivity --- p.63
Chapter 4.2.3.4. --- Stability --- p.65
Chapter 4.2.3.5. --- Hysteresis --- p.66
Chapter 4.2.4 --- Summary --- p.68
Chapter 4.3 --- Fabrication of EG-CNTs Flow Sensor --- p.70
Chapter 4.3.1. --- Fabrication Procedure --- p.70
Chapter 4.3.2 --- Experimental Setup --- p.73
Chapter 4.4 --- Characterization of EG-CNTs Flow Sensor --- p.74
Chapter 4.4.1. --- Typical Response --- p.74
Chapter 4.4.2. --- Power Consumption --- p.75
Chapter 4.4.3. --- Repeatability --- p.77
Chapter 4.4.4. --- Flow Sensitivity --- p.78
Chapter 4.5 --- Summary --- p.79
Chapter 5. --- Conclusion --- p.80
Chapter 6. --- Bibliography --- p.83