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Characterization of Porous Anodic Aluminum Oxide Film by Combined Scattering TechniquesHe, Xueying January 2013 (has links)
No description available.
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Mesoporous Silica Nanowires by Space-confined Organic-Inorganic Hybrid Self-AssemblyLai, Peng 04 April 2007 (has links)
No description available.
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Fabrication of Large Area Anodic Alumina Oxide (AAO) Arrays and Its ApplicationsYang, Kun-lin 30 July 2007 (has links)
The AAO membrane with nanopore arrays were fabricated by anodizing highly pure aluminum foils (99.9995%) in electrolyte. Ordered array have been obtained under optimized anodizing condition, and pore diameter can be controlled by different anodic voltage and electrolyte. After we got such an ordered arrangement porous alumina array, the following analysis of the material optical properties were characterized. Photoluminescence measurements showed a strong PL peak in blue. The PL peak was 420nm excited by He-Cd laser. From the transmittance spectra, the results showed that material was transparent above 400nm. The XRD spectra of AAO without and with annealing, both showed the diffraction peaks of (311)¡B(400)¡B(440), corresponding to the £^-Al2O3 phase appear.
High ordered anodic porous alumina with holes interval 65nm was prepared in mixture solution of H3PO4 and H2SO4 under high temperature and high concentration. Through the use of porous anodic alumina masks, nanopore arrays were fabricated on Si¡BGaAs substrates by reactive ion etching. Also, metal nanodot arrays were formed through the AAO mask by evaporation. Thin AAO slabs also enhance the light extraction from the QDs, and control the PL emission wavelength.
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Fabrication of self-assembly porous alumina and its applicationsTsai, Kun-Tong 10 July 2006 (has links)
In this thesis, the growth and fabrication of the self-assembly ordered porous alumina have been investigated. First, well-ordered honeycomb array can be obtained in large area under well-anodizing condition. The diameter of formed porous alumina was about 40 to 80 nm. Pore diameter can be tuned by different voltage and electrolyte. After we got such an ordered-arrangement porous alumina array, the following analysis of the material optical properties were characterized. In the luminescence behavior, photoluminescence (PL) measurements showed a strong PL peak in blue. The PL peak was at 420 nm excited by He-Cd laser. Material transmittance was also detected, the result showed that material was transparent above 400 nm.
On the other hand, the porous alumina membrane can be used as a mask. For working as negative mask, we evaporated the metal such as Au or Ti into the membrane and the metal filled into the porous to adhere to the semiconductor substrate. After lifting-off the membrane, the metal nanadots was formed on the substrate. The size and the position of these metal nanodots were distinctly-controlled by the mask. For working as replica mask, we have used the membrane as an etching mask to transfer the pattern to the semiconductor substrate successfully. This technique has the advantages of low cost and large area for nano-fabrication.
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Optical Application of Anodic Aluminum OxideChien, Wei-han 29 July 2008 (has links)
Abstract
The AAO membrane with nanopore arrays were fabricated by anodizing highly pure aluminum foils (99.9995%) in electrolyte under steady voltage. Pore diameter can be controlled by different anodic voltage(from 30 to 50 V) and electrolyte, on the other hand, thickness is proportioned to anodizing time , and interpore could follow this rule(a = 15.4+2.63¡Ñv) , and minimum radius of pore could reach 15nm . The XRD spectra of AAO without and with annealing, both showed the diffraction peaks of (311)¡B(400)¡B(440), corresponding to the £^-Al2O3 phase . Before fabricating AAO, we would polish under low temperature and then clean alumina foil in order to reduce surface roughness that is good for better order and regular.
Through the use of porous anodic alumina masks, Au nanodot arrays deposited on Si by E-gun with AAO mask. Subsequently, the AAO mask was removed by H3PO4. Under the same procedure, we can fabricate 80nm of the diameter of pore and apply this mask on wafer of laser constructure . Because of regular hexagonal pore array, we may get the photonic crystal effect. During PL experiment, we got the result that AAO could increase light extraction of quantum dot from C237 wafer and controlled emission peak from C238 and C196 wafer and position of peak could shift to 1140nm. We hope nanodot array on wafer of laser structure could control emission peak.
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An Ethical Critique of the AAO Principles of Ethics and Code of Professional ConductPodray, Brad Andrew January 2010 (has links)
The American Association of Orthodontists(AAO) adopted its Code of Ethics and Code of Professional Conduct in May of 1994. This document is meant to provide guidelines for ethical behavior amongst orthodontic professionals. Its main purpose is to protect the public from ethically unsound actions that could be committed by members of the AAO. All members of the AAO agree to abide by the Code, as stated within its preamble: "By accepting membership, all members assume an obligation of self-discipline above and beyond the requirements of laws and regulations, in accordance with these Principles." This study represents a critique of the AAO Code. As the field of medical ethics evolves, so must the documents that govern ethical behavior. The last revision took place in May of 2009 and the wording of the current document can be misinterpreted or abused. The current code leans heavily towards an Agent/Commercial model of practice, where the Orthodontist's role is influenced greatly by patient request and business ambitions. The purpose of this study was to utilize accepted schools of thought in ethical literature to do the following: (1) Point out ethical flaws and weak points in the AAO Code. (2) Present corrections for the Code in order to clarify potential points of contention. These corrections will articulate rules that promote a partnership between practitioner and patient. To accomplish these goals, the Code will be analyzed, line by line, for redundancies, faults, or potential misinterpretations. Principles and Advisory Opinions which can be improved upon will be labeled as "weak." All weak statements will be reformed in a manner where the weak aspects no longer play a role in the Code. The reformed statements will promote the Partnership model of practice in favor of Agent and Commercial models. The Conclusions of the study are as follows: (1) Principle I can be improved by changing it to the following phrase: Members shall be dedicated to providing the highest possible quality orthodontic care to his/her patients within standards commensurate with the accepted science and techniques of orthodontics, the clinical aspects of the patient's condition, and with due consideration being given to the needs and desires of the doctor and patient within a relationship based on partnership. (2)Advisory Opinion IE. should be changed to the following: A second opinion should include a diagnosis and treatment plan recommended to the patient. It must be honest and focus on the facts presented. It is unethical to propound a specific technique, philosophy, training or ability as superior without presenting scientific literature, at least summarized or simplified, to the patient to support claims made. A second opinion must disclose to the patient any conflict of interest of the member providing the opinion. (3) The phrasing of Advisory Opinion IF. is made stronger with the following wording: Patients should be informed of their oral health status without disparaging comments about the patient's prior treatment.(4) The phrasing of Advisory Opinion IG. is made stronger with the following wording: Members should inform their patients of their prognosis, any proposed treatment, and any reasonable alternatives, so that the patient understands their treatment decisions. / Oral Biology
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Synthèse et étude d’hétérostructures diélectrique/magnétique dans des membranes d’alumine nanoporeuses / Synthesis and study of dielectric/magnetic heterostructures within nanoporous alumina templatesSallagoity, David 17 December 2015 (has links)
Le contrôle de la polarisation et de l’aimantation par le biais de champs magnétiques et électriques respectifs font des systèmes magnétoélectriques des candidats prometteurs à de nombreuses applications, parmi lesquelles les dispositifs micro-ondes, les dispositifs de stockage de données à haute densité, etc. L’élaboration d’hétérostructures toujours plus innovantes reste un défi majeur dans le but d’optimiser les densités d’interfaces entre les phases ferroélectriques et ferromagnétiques,et ainsi promouvoir les interactions de couplage mécaniques. Au cours de ce projet de thèse, deux stratégies sont mises en oeuvre pour la conception des matériaux : i) une structure coeur-écorce de type (1-1) composée de nanofils ferromagnétiques (1) dans des nanotubes ferroélectriques (1) àl’intérieur d’une membrane nanoporeuse tridimensionnelle auto supportée etii) une structure en couche mince de type (1-3) constituée de nanofils ferromagnétiques (1) supportés sur un substrat rigide et encapsulés dans une matrice ferroélectrique (3). / Controlling polarization or magnetization by an applied magneticand electric field respectively make magnetoelectric systems promisingcandidates for applications in microwave devices, high density data storagedevices, etc. Designing innovative magnetoelectric heterostructures is thus achallenge to optimize interface density between both ferroelectric andferromagnetic phases, and promote mechanical coupling interactions. In thisthesis project, two strategies are followed for material design: i) 1-1 coreshellstructure with ferromagnetic nanowires (1) inside ferroelectricnanotubes in a self-supported tridimensionnal porous template (1) and ii) 1-3structure where ferromagnetic nanowires (1) are supported on a substrateand embedded in a ferroelectric matrix (3).
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Vertikálně uspořádaná pole CdS nanotyčinek pro aplikace v solárních článcích / Vertically aligned CdS nanorod arrays for solar cell applicationsHroch, Daniel January 2016 (has links)
This thesis describes the deposition of nanoparticles into nanoporous alumina templates. Nanoparticles of cadmium sulphide were chosen thanks to wide band gap of 2,45 eV. CdS is desired semiconductor promising better efficiency when comes to solar radiation conversion to useful energy. Theoretical part consists of explanation of photovoltaic principles, band-gap theory of materials, currently available technologies to manufacture solar cells and their efficiencies. Next part introduces the approaches of manufacturing nanoporous templates from aluminium (Anodized Aluminium Oxide, AAO) in details together with options to deposit cadmium sulphide into these structures. There is also brief description of deposition based on vacuum filtration. Experiments were made in Laboratory of Microsensors and Nanotechnologies at Faculty of Electrical Engineering and Communication in Brno University of. The experimental chapter describes manufacturing process of AAO and deposition via vacuum filtration. Samples were evaluated by Scanning Electron Microscopy.
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Nanowire Zinc Oxide MOSFET Pressure SensorClavijo, William 30 April 2014 (has links)
Fabrication and characterization of a new kind of pressure sensor using self-assembly Zinc Oxide (ZnO) nanowires on top of the gate of a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is presented. Self-assembly ZnO nanowires were fabricated with a diameter of 80 nm and 800 nm height (80:8 aspect ratio) on top of the gate of the MOSFET. The sensor showed a 110% response in the drain current due to pressure, even with the expected piezoresistive response of the silicon device removed from the measurement. The pressure sensor was fabricated through low temperature bottom up ultrahigh aspect ratio ZnO nanowire growth using anodic alumina oxide (AAO) templates. The pressure sensor has two main components: MOSFET and ZnO nanowires. Silicon Dioxide growth, photolithography, dopant diffusion, and aluminum metallization were used to fabricate a basic MOSFET. In the other hand, a combination of aluminum anodization, alumina barrier layer removal, ZnO atomic layer deposition (ALD), and wet etching for nanowire release were optimized to fabricate the sensor on a silicon wafer. The ZnO nanowire fabrication sequence presented is at low temperature making it compatible with CMOS technology.
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Fabrication of bovine serum albumin nanotubes through template assisted layer by layer assemblyZhang, Dawei 06 May 2009 (has links)
One-dimensional nanostructures have offered unique advantages in many fields. Protein based nanotubes, in particular, are desirable for biomedical applications due to their ease of functionlization and intrinsic biocompatibility. Template-assisted methods are widely used to fabricate cylindrical nanostructures like carbon nanotubes, metal nanowires, polymer nanorods, etc. In the fabrication of protein nanostructures, the layer by layer (LbL) technique has long been applied to deposit protein multilayers on planar and spherical substrates. The success in each area led to the conclusion that the combination of these two techniques will potentially bring us the capability of fabricating protein nanotubes in a more controllable fashion. In this work, protein nanotubes have been successfully deposited inside nanoscopic pores by sequential filtration of bovine serum albumin (BSA) solution at pH 3.8 and pH 7.0 through the channels in the anodic aluminum oxide (AAO) template. The morphologies of the obtained nanostructures have been examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also, a simple analysis from UV/Vis spectroscopy has shown that the solutions used in our experiment will not significantly damage the bioactivity of BSA. Our future work will focus on strengthening the mechanical stability of the protein nanotubes and controlling their morphology more precisely.
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