Página 12 dos resultados de 2573 itens digitais encontrados em 0.200 segundos

‣ A technical evaluation of a novel cell-surface cytokine detection technology

Peng, Eileen X. (Eileen Xiao Fei), 1980-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 69 leaves; 3050065 bytes; 5575439 bytes; application/pdf; application/pdf
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by Eileen Peng.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2003.; Includes bibliographical references (leaves 65-67).; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.

‣ Printed circuit board materials : an evaluation of manufacturing technologies and market requirements

Ng, Lee Hong
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 194 leaves; 13326077 bytes; 13325834 bytes; application/pdf; application/pdf
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by Ng, Lee Hong.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990.; Includes bibliographical references (leaves 190-194).

‣ SiGe virtual substrate engineering for integration of III-V materials, microelectromechanical systems, and strained silicon MOSFETs with silicon

Currie, Matthew Thomas, 1973-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 191 p.; 13591098 bytes; 13590855 bytes; application/pdf; application/pdf
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by Matthew Thomas Currie.; Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2001.; Includes bibliographical references (p. 184-191).

‣ Templated aqueous synthesis of inorganics within carboxyl-containing block copolymer domains

Boontongkong, Yot
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 153 leaves; 56055862 bytes; 56055614 bytes; application/pdf; application/pdf
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Template-directed, aqueous-based syntheses of nanoscale inorganic materials in carboxyl-functionalized block copolymer domains (nanoreactors) were demonstrated. First, the successful application of electroless metal deposition within the sub-surface lamellar domains of an amphiphilic block copolymer is presented. Several electroless metals were selectively deposited inside the interconnected network of the water-permeable block domains containing pre-loaded palladium, which served as the spatially localized deposition catalyst. The technique proved to be a facile means to rapidly deposit large amounts of metals within the hydrophilic block domains, despite limitations on the transport of plating reagents into the bulk templates. The simple process yielded novel nanocomposites consisting of alternating layers of metal with those of the hydrocarbon matrix. The extent of metal deposition within the bulk block copolymer templates was controlled by adjusting the deposition rate and deposition time. Second, unique self-assembled thin film templates comprising in-plane arrays of nanosized surface cavities were investigated. The micellar thin films, formed by direct casting of kinetically stable styrene(PS)-acrylic acid(PAA) block copolymer reverse micelles from toluene onto solid substrates...

‣ Analysis of ultra-narrow ferromagnetic domain walls

Jenkins, Catherine A. (Catherine Ann), 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 71 p.; 2419937 bytes; 2419737 bytes; application/pdf; application/pdf
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A mathematical analysis of ultra-narrow ferromagnetic domain walls was undertaken, with graphical plots coded in the programming language TrueBASIC. An intrinsic inter-atomic potential stemming from the breakdown of the continuum approximation of matter is calculated and its contribution to the coercive force of hard materials is depicted. The interaction of a very narrow domain wall with a similarly narrow planar defect is analyzed. Time-dependent motion of such walls is modeled for various external driving forces and in different combinations of material parameters. This work was completed in parallel with a study of narrow crystallographic magnetic discontinuities known as twin boundaries, and was designed to gain an intuition into the control of high-anisotropy magnetic recording devices. The equations developed here would be particularly useful as a basis for approaching the calculations of the stability of high-density storage media.; by Catherine Jenkins.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004.; Includes bibliographical references (p. 35).

‣ Commercial application of aluminum honeycomb and foam in load bearing tubular structures

Bartolucci, Stefano, 1976-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 156 leaves; 8319626 bytes; 8340736 bytes; application/pdf; application/pdf
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Small dimension engineering tubular structures subjected to a complex load system are designed like hollow circular shells. For minimum weight design, the ratio between the shell radius and the thickness has to be as large as possible, but its maximum value is limited by the onset of local buckling. Tubular natural structures subjected to a complex load system have often an outer shell of solid material supported by a low density, compliant core, which makes them more resistant to local buckling. Biomimicking of natural constructions offer the potential to improve the design of small diameter tubular engineering structures. Here, the fabrication technology of biomimicked engineering tubular structures integrating aluminum foam or honeycomb as core material is discussed. A viability analysis is presented including technical performance, cost, utility, and risk assessments. Aluminum compliant core shells have potential for substituting CFRP and aluminum tubular structures in aerospace and high-level sport applications. The case of sailboat masts was considered in detail. Results of our analysis proved that use of honeycomb as core material can lead to a significant reduction of the mast weight. Business opportunities based on this application are discussed.; by Stefano Bartolucci.; Thesis (M. Eng.)--Massachusetts Institute of Technology...

‣ MEMS-based resonant sensor arrays : selective detection of volatile and toxic chemicals; Microelectromechanical systems-based resonant sensor arrays : selective detection of volatile and toxic chemicals

Whitfield, George C., 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 59 leaves; 3738430 bytes; 3743743 bytes; application/pdf; application/pdf
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With growing concerns about homeland security, public health, and environmental cleanliness, there is a strong need today for robust chemical sensing systems that are portable in addition to being highly sensitive. While there are many options available for gaseous chemical detection and identification, not all are well-suited toward the creation of a portable device. Boston MicroSystems, Inc. (BMS) has developed a resonant chemical sensor that is predicted to meet the performance needs of the current market in terms of gas sensitivity, operational reliability, and overall device portability. Desirable device characteristics are attained through integrating aluminum nitride and silicon carbide in processes that are protected through a strong base of intellectual property. By developing a standardized platform for gas detection based on this sensor technology, barriers to entering the targeted markets may be overcome.; by George C. Whitfield.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004.; Includes bibliographical references (leaves 58-59).

‣ Investigation of the stress corrosion cracking susceptibility of annealed and heat treated alloy 625 castings and forgings in sea water; Stress corrosion cracking susceptibility of annealed and heat treated alloy 625 castings and forgings in sea water, Investigation of the

Jones, Eric Merwin
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 104 leaves; 6074705 bytes; 6085531 bytes; application/pdf; application/pdf
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by Eric Merwin Jones.; Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1987.; Bibliography: leaves 100-104.

‣ Investigation of short-range surface forces to develop self-organizing devices by Steven M. Tobias.

Tobias, Steven M., 1980-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 69 leaves; 3964504 bytes; 3971298 bytes; application/pdf; application/pdf
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Force spectra from atomic force microscopy were used to verify surface energy components of indium tin oxide and mesocarbon microbeads. These materials were selected based on spectroscopic and thermodynamic parameters to be used in self-organizing devices. Estimates for surface energy were based on the van der Waals contribution described by Lifshitz theory and the polar contribution described by electron donor and acceptor components. This new type of device assembly process can be self-organizing based on the principle of like particle attraction and dissimilar particle repulsion. A thin insulting barrier could be inserted at the interface between two different types of particles, enabling junction formation. The criteria necessary to create a device based on surface energy components was specified.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.; Leaf 69 blank.; Includes bibliographical references (leaves 65-68).

‣ A new model for electric force microscopy and its application for electrostatically generated phase difference in tapping mode AFM; New model for EFM microscopy and its application for electrostatically generated phase difference in tapping mode Atomic Force Microscope

Stone, Peter (Peter Robert)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 37 leaves; 1632936 bytes; 1632286 bytes; application/pdf; application/pdf
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The harmonic force balance method was used to model and simulate electric force microscopy (EFM) and electrostatically generated phase difference in tapping mode AFM (EPTA) measurements. Simulations show that the harmonic force balance approach matches and explains EFM and EPTA experimental results well. Simulations also show that the model depended on both geometric and materials parameters. The harmonic force balance model was subsequently used to directly simulate a previously performed EPTA experiment. Data obtained from the model showed a remarkable similarity to the experimentally obtained data, thus validating the use of the harmonic force balance model to simulate EPTA data.; by Peter Stone.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.; Includes bibliographical references (leaf 37).

‣ The dynamic behavior of nylon and polyester rope under simulated towing conditions

Toomey, Christopher James
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 102 leaves; 3332941 bytes; 3332750 bytes; application/pdf; application/pdf
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by Christopher James Toomey.; Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1988, and (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1988.; Includes bibliographical references.

‣ Understanding the economics and material platform of bidirectional transceiver for plastic optical fiber

Gusho, Genta
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 76 leaves; 4546054 bytes; 4549207 bytes; application/pdf; application/pdf
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Limitations of electrical wires result in distortion and dispersion of the signal for long distances. That have emerged optical communication as the only way of communication for long distances. For medium distances optics can support the high data rates required by the latest applications. Optical networks are becoming the dominant transmission medium as the data rate required by different applications increases. The bottleneck for implementing optical instead of electric networks for medium distances, like local area network, is the cost of the optical components and the cost of replacing the existing copper network. This thesis will discuss the possible cost benefits that come from the use of different materials like plastic optical fiber instead of silica fiber or Si, Si/Ge instead of InP or GaAs for the transceiver as well as the trade offs between the performance and cost when discrete transceiver is replaced by the monolithically integrated transceiver, by using a process based cost model.; by Genta (Meco) Gusho.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.; Includes bibliographical references (leaves 74-76).

‣ Evaluation of superhydrophilic polyelectrolyte multilayered films for anti-fogging applications; Evaluation of superhydrophilic PEM films for anti-fogging applications

Lim, Jonathan Tze Ming
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 60 leaves
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Polyelectrolyte multilayered (PEM) films created by an aqueous-based layer-by-layer assembly technique have been widely studied in the past decade. Owing to the simple, versatile and yet well-controlled nature of this technique, many potential applications of these thin films have also been proposed and explored. This thesis presents a recent work in fabricating nanoporous PEM films with superhydrophilic characteristics that demonstrate great promise for anti-fogging and anti-reflection glass coating applications. The automotive glass industry is then identified as a potential market for this technology, and competing anti-fogging technologies as well as relevant intellectual property are reviewed to further ascertain the commercial viability of this product. Finally a few possible business models for bringing this product to market are proposed and evaluated.; by Jonathan Tze Ming Lim.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006.; Includes bibliographical references (leaf 56-60).

‣ Applicability of undermatched welds for high strentgh steel structures

Kafetsis, Nikolas K
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 184 leaves
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by Nikolas K. Kafetsis.; Thesis (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995.; Includes bibliographical references (leaves 182-184).

‣ General approach for the application of Supramolecular NanoStamping (SuNS) to surfaces of all types

Thévenet, Sarah
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 83 leaves
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To novel ideas must correspond novel fabrication techniques, that enable the transfer of technologies from laboratories to the market. The success of microelectronics for example can not be separated from the success of the revolutionary manufacturing technology that has fed its expansion. The same is now true for nano- and biotechnologies that, to a large extent, have yet to find the technologies that will best answer their processing needs. The question is to find an approach that will enable the production of devices with the required resolution, complexity and versatility, together with the necessary reliability and potential for high-throughput. Supramolecular NanoStamping (SuNS), a DNA based lithography technique developed in our group, is trying to answer to this set of requirements. In this thesis, I present a new development in this lithography technique, expanding its application to a broad new range of substrates in a substrate-independent fashion. This work, which I conducted during the course of my master, proves the ability of SuNS to adapt to very diverse environments and applications.; by Sarah Thévenet.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.; Includes bibliographical references (leaves 77-83).

‣ Assessment of ion-selective optical nanosensors for drug screening applications

Yun, Hannah
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 69 p.
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Ion channels represent an important category of drug targets. They play a significant role in numerous physiological functions, from membrane excitation and signaling to fluid absorption and secretion. An ion-channel assay system using optical nanosensors has recently been developed. This high-throughput, high-content system improves on the existing patch clamp and fluorescent dye technologies that presently dominate the ion-channel screening market. This paper introduces the nanosensor technology, reviews the current market for ion-channel assays, assesses the costs associated with the nanosensors, and evaluates their commercialization potential.; by Hannah Yun.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.; "September 2007."; Includes bibliographical references (p. 67-69).

‣ Application of microfluidic device to malaria diagnosis

Zhang, Rou
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 55 p.
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Of many diagnostic devices and technology developed, microfluidics could be superior in terms of ease of fabrication, cost, portability, speed and sensitivity. The application of diagnosis of malaria infection by microfluidics is studied. Malaria infected red blood cells will cause a cell stiffening, and the different behaviors of iRBCs could be detected by microfluidics. The malaria market and various business model is analyzed, and a suitable business model could be chosen to commercialize this device. However, limitations exist at current stage.; by Rou, Zhang.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.; "September 2007."; Includes bibliographical references (p. 45-47).

‣ Commercialization of cryptomelane-type manganese oxide (OMS-2) nanowire paper oil sorbent; Commercialization of OMS-2 nanowire paper oil sorbent

Soo, Haw Yun
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 40 leaves
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Cryptomelane-type Manganese oxide (OMS-2, a group of Octahedral Molecular Sieves) nanowire paper exhibits interesting properties: reversible wettability, oleophilic while being hydrophobic, and high thermal stability. These properties open up possible markets for commercialization. This thesis reviews the market potential of each of these properties and explores the competitiveness of the nanowire paper in the proposed markets. The proposed values of this technology are in its high selective absorbency towards oil, high performance over cost metric and its high thermal stability. Its thermal stability enables a thermal desorption type process to regenerate and recycle the sorbent for reuse. This translates into further differentiation and provides greater value for the users.; by Haw Yun Soo.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.; Includes bibliographical references (leaf 36).

‣ pH-sensitive resist materials for combined photolithographic patterning of proteins and fluid lipid bilayers

Shah, Mirat
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 34 p.
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Photolithography of a pH-sensitive photoresist polymer was performed to pattern both lipid bilayers and proteins onto the same surface. The motivation behind this was to create a substrate mimicking an array of antigen- presenting cells. The substrate would consist of signaling ligand, biotin anti- CD3, bound to a lipid bilayer in a regular array of patches. The fluidity of the lipid bilayer would impart mobility to the signaling ligand. It was found that under appropriate substrate fabrication conditions, lipid bilayers and their associated ligand do segregate to the desired signaling patches. Additionally, the bilayer in these regions is fluid, and is potentially bioactive. This bodes well for our system as a future platform to study the actions of the helper T cell and antigen- presenting cell at the immunological synapse.; by Mirat Shah.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.; Includes bibliographical references (p. 33-34).

‣ Pulse-field actuation of collinear magnetic single crystals

Jenkins, Catherine A. (Catherine Ann), 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 34 p.; 1177750 bytes; 1176987 bytes; application/pdf; application/pdf
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Ferromagnetic shape memory alloys (FSMAs) are a class of alloys that exhibits the shape memory effect, as in the alloy nickel-titanium, sometimes known as Nitinol. In FSMAs, though, the shape changes are not brought on just by changes in temperature or mechanical stresses, but can also be driven by the application of a relatively small magnetic field. The large strains exhibited by such materials are a result of the coexistence of several features, including a thermoelastic martensitic transition, and a ferromagnetic martensite (non-equilibrium, low-temperature) phase. The magnetocrystalline anisotropy must also be large, as seen in similar alloys such as iron-palladium (Fe₇₀Pd₃₀) [1]. Nickel-manganese-gallium is an FSMA that has shown up to 10% strain in certain orientations as an effect of unconstrained magnetic actuation [4]. To achieve cyclic actuation in FSMAs, the field-induced extension has conventionally been reversed by a compressive mechanical stress from a spring or field orthogonal to the actuating field. The use of a second FSMA crystal to provide the reset force was unreported. Collinear single crystals are shown here to be able to induce a 2.8% reset strain against one another when subjected alternately to individual pulsed magnetic fields in a custom designed and constructed apparatus. A setup of this type could be used in a bistable microswitch...