Pendleton Artificial Reef: annual progress report presented to Southern California Edison Company

(PDF contains 82 pages.)

On The Thermally Induced Cracking Of A Segmented Coating Deposited On The Outer Surface Of A Hollow Cylinder

In this work, the thermally induced cracking behavior of a segmented coating has been investigated. The geometry under consideration is a hollow cylinder with a segmented coating deposited onto its outer surface. The segmentation cracks are modeled as a periodic array of axial edge cracks. The finite element method is utilized to obtain the solution of the multiple crack problem and the Thermal Stress Intensity Factors (TSIFs) are calculated. Based on dimensional analysis, the main parameters affecting TSIFs are identified. It has been found that the TSIF is a monotonically increasing function of segmentation crack spacing. This result confirms that a segmented coating exhibits much higher thermal shock resistance than an intact counterpart, if only the segmentation crack spacing is narrow enough. The dependence of TSIF on some other parameters, such as normalized time, segmentation crack depth, convection severity as well as material constants, has also been discussed. (C) 2008 Elsevier B.V. All rights reserved.

Generation of sub-5 fs pulses through cascade of filamentation and hollow fiber compression

A pulse-compression scheme based on cascade of filamentation and hollow fiber has been demonstrated, Pulses with duration of sub-5 fs and energy of 0.2 mJ near 800 nm have been generated by compressing the similar to 40 fs pulses from a commercial laser system. This method is promising to generate near monocycle high energy pulses. [GRAPHICS] Measured autocorrelation curve of the final compressed pulses with duration of sub-5 fs (black solid) and the simulated autocorrelation curve of 4.6 fs pulse near 800 rim (red dash) (C) 2008 by Astro Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA

A multi-scale approach to shaping carbon nanotube structures for hollow microneedles

The concept of a carbon nanotube microneedle array is explored in this thesis from multiple perspectives including microneedle fabrication, physical aspects of transdermal delivery, and in vivo transdermal drug delivery experiments. Starting with standard techniques in carbon nanotube (CNT) fabrication, including catalyst patterning and chemical vapor deposition, vertically-aligned carbon nanotubes are utilized as a scaffold to define the shape of the hollow microneedle. Passive, scalable techniques based on capillary action and unique photolithographic methods are utilized to produce a CNT-polymer composite microneedle. Specific examples of CNT-polyimide and CNT-epoxy microneedles are investigated. Further analysis of the transport properties of polymer resins reveals general requirements for applying arbitrary polymers to the fabrication process.

The bottom-up fabrication approach embodied by vertically-aligned carbon nanotubes allows for more direct construction of complex high-aspect ratio features than standard top-down fabrication approaches, making microneedles an ideal application for CNTs. However, current vertically-aligned CNT fabrication techniques only allow for the production of extruded geometries with a constant cross-sectional area, such as cylinders. To rectify this limitation, isotropic oxygen etching is introduced as a novel fabrication technique to create true 3D CNT geometry. Oxygen etching is utilized to create a conical geometry from a cylindrical CNT structure as well as create complex shape transformations in other CNT geometries.

CNT-polymer composite microneedles are anchored onto a common polymer base less than 50 µm thick, which allows for the microneedles to be incorporated into multiple drug delivery platforms, including modified hypodermic syringes and silicone skin patches. Cylindrical microneedles are fabricated with 100 µm outer diameter and height of 200-250 µm with a central cavity, or lumen, diameter of 30 µm to facilitate liquid drug flow. In vitro delivery experiments in swine skin demonstrate the ability of the microneedles to successfully penetrate the skin and deliver aqueous solutions.

An in vivo study was performed to assess the ability of the CNT-polymer microneedles to deliver drugs transdermally. CNT-polymer microneedles are attached to a hand actuated silicone skin patch that holds a liquid reservoir of drugs. Fentanyl, a potent analgesic, was administered to New Zealand White Rabbits through 3 routes of delivery: topical patch, CNT-polymer microneedles, and subcutaneous hypodermic injection. Results demonstrate that the CNT-polymer microneedles have a similar onset of action as the topical patch. CNT-polymer microneedles were also vetted as a painless delivery approach compared to hypodermic injection. Comparative analysis with contemporary microneedle designs demonstrates that the delivery achieved through CNT-polymer microneedles is akin to current hollow microneedle architectures. The inherent advantage of applying a bottom-up fabrication approach alongside similar delivery performance to contemporary microneedle designs demonstrates that the CNT-polymer composite microneedle is a viable architecture in the emerging field of painless transdermal delivery.

Generation of a high-quality partially coherent dark hollow beam with a multimode fiber

We report the experimental generation of a high-quality partially coherent dark hollow beam (DHB) by coupling a partially coherent beam into a multimode fiber (MMF) with a suitable incidence angle. The interference experiment of the generated partially coherent DHB passing through double slits is demonstrated. It is found that the coupling efficiency of the MMF, the quality, and the coherence of the generated partially coherent DHB are closely controlled by the coherence of the input beam. (c) 2008 Optical Society of America.

Comparison of marketing policies applied by the same company in different countries and analysis of the reasons for the differences

The focus of this project is going to be, as the title indicates, on the comparison of marketing policies applied by the same company in different countries and analysis of the reasons for the differences. In order to do that, I have selected the company Nestlé to analyze the marketing decisions it makes across national boundaries to market the brand of Kit Kat and keep it as a leader snack worldwide. After having analyzed the brand in all continents, I can say the execution of the strategy used by Nestlé with Kit Kat really matches the planning of the strategy which is to think globally and act locally. Nestlé uses global brand identity but, from the internal point of view, it uses local ingredients and gives autonomy to its local branches based in different countries to make pricing and distributions decisions and therefore satisfy different consumers’ needs and preferences in local environments where changes happen very rapidly. The “glocal” approach to marketing is an effective way for Nestlé Kit Kat to stay focused on the consumer in worldwide markets.