No description available.

This study has two purposes: First, the catalyst-coated membrane (CCM) method to produce high performance and high utilization of electrode, and the other is to enhance the fuel cell performance with the heterogeneous carbon fiber bunch framework of stack. First, to establish an ideal electrode structure, there has an intensive triple phase boundaries. We will describe how the procedure of reliable and practical electrode improved following the optimization of (1) the spray system, and (2) the catalyst dispersion. We will also focus (3) modification of the spray system, and (4) electrode performance analysis. In addition, investigate of the single cell performance in heterogeneous carbon fiber bunch framework. We will find that: (1) Increasing the catalyst loading and concentrated the catalyst activation reaction, can be improve the electrode performance and catalyst utilization. (2) Coating a thin conductive layer onto membrane electrode (ME), be a precise hot-pressue process in the Stack and MEA or GDL and ME, can be reduce the contact resistance. Specially, reduce the carbon fiber coverage fraction with electrode area, result the activation reaction decay and ohmic loss obviously. (3) Increasing the gas flow rate, can enhance the mass transfer performance, but increase the pressure of the reaction gas, can¡¦t significant effect on performance. Besides, when the stack is anode side up, seems favorable to the exclusion the generate water of cathode.

Iron oxide-bearing minerals have long been recognized as an effective reactive media for arsenic-contaminated groundwater remediation. This research aimed to develop a technique that could facilitate in situ oxidative precipitation of Fe3+ in a soil (sand) media for generating a subsurface iron oxide-based reactive barrier that could immobilize arsenic (As) and other dissolved metals in groundwater. A simple in situ arsenic treatment process was successfully developed for treating contaminated rural groundwater using iron oxide-coated sand (IOCS). Using imbibition flow, the system facilitated the dispersive transport of ferrous iron (Fe2+) and oxidant solutions in porous sand to generate an overlaying blanket where the Fe2+ was oxidized and precipitated onto the surface as ferric oxide. The iron oxide (FeOx) emplacement process was significantly affected by (1) the initial surface area and surface-bound iron content of the sand, (2) the pH and solubility of the coating reagents, (3) the stability of the oxidant solution, and (4) the chemical injection schedule. In contrast to conventional excavate-and-fill treatment technologies, this technique could be used to in situ replace a fresh iron oxide blanket on the sand and rejuvenate its treatment capacity for additional arsenic removal. Several bench-scale experiments revealed that the resultant IOCS could treat arsenic-laden groundwater for extended periods of time before approaching its effective life cycle. The adsorption capacity for As(III) and As(V) was influenced by (1) the amount of iron oxide accumulated on the sand surface, (2) the system pH, and (3) competition for adsorption sites from other groundwater constituents such as silicon (Si) and total dissolved solids (TDS). Although the IOCS could be replenished several times before exhaustion, the life cycle of the FeOx reactive barrier may be limited by the gradual loss of hydraulic conductivity induced by the imminent reduction of pore space over time.

<p>The mechanical behaviour of coated papers during folding has been investigated. This problem has been studied with experimental techniques and numerical analyses in order to give a better understanding of the folding properties of coated papers pertinent to the mechanical behaviour in general, and particularly cracking along the fold. </p><p>A microscopy investigation has been performed. The surface of the folded paper has been carefully examined to study the event of fracture and related issues. The influence of the grammage on the cracking event has been studied and it was shown that the coating material would not fail if the paper sample was sufficiently thin. It was found that a stress or strain based criterion is sufficient to describe the cracking of the coating layers and that the anisotropy of paper should be taken into account when studying the folding process. </p><p>The finite element method has been used for the numerical analyses remembering that the geometry of the problem is rather complicated, excluding a solution in analytical form. Using different constitutive models for the base stock, it has been shown that the deformation of the coated paper during folding is much governed by the paper substrate. The numerical results also suggested that particular forms of plastic anisotropy can substantially reduce the maximum strain levels in the coating. Furthermore, it has also been shown that delamination buckling, in the present circumstances, has a very small influence on the strain levels in the coating layer subjected to high tensile loading. </p><p>Dynamic effects have also been studied and it has been shown that a quasi-static analysis of the problem is sufficient in order to describe many of the important features related to cracking. An attempt to model strong anisotropy of paper has been presented and the results indicate that the large anisotropy in the thickness direction of coated papers needs to be taken into account in order to fully understand the mechanics of folding. </p><p>Finally, an experimental investigation has been presented in order to study if important mechanical properties of the coating material could be determined by microindentation techniques. The results presented indicate that microindentation can be a powerful tool for characterization of these materials, but only if careful efforts are made in order to account for the influence from plasticity as well as from boundary effects. </p><p><b>KEYWORDS:</b> folding, coated papers, finite element method, cracking, indentation, anisotropy, plasticity.</p>

<p>Vacuum insulation panels, VIPs, constitute a new insulation material, 6 to 8 times better than traditional insulation materials, which utilizes the positive influence vacuum has on the thermal properties of certain materials. A VIP is a composite with a flat core enclosed by an envelope preventing the core to fill with gas. The vacuum in the core is vital to reach thermal conductivities down to 0,0035 W/(m K), if the vacuum is lost the panel has reached the end of its service life time. Metal sheets would the preferred material to create an impermeable envelope but would creates a large thermal bridge at the edges of a panel when it folds over the edges of the panel.</p><p>A serpentine edge has been proposed in order to deal with this large thermal bridge. This serpentine edge has been evaluated first as a numeric model in software and then by measuring on a prototype edge element in a hot and cold plate instrument. Measured temperatures were used to validate the numerical model. Results show that a serpentine edge can greatly reduce the thermal bridge if designed correctly.</p><p>Another direction taken in the development of the VIP barrier is to use very thin metal layers, metallization layer or coating, incorporated into multi layered polymer composite film. This creates barrier films with very good barrier properties and only small thermal bridges. The modeling of gas flux through films with more than one coating has only just started. Existing models for flux through multi coated films all assume that flux is only taking place through defects in the coating layers, that all defects are of the same size and that all defects are positioned in square lattices. The model discussed herein use the same assumption of flux through pinholes only but it does take defect sizes and positions into account. Barrier film, from a regular vacuum insulation panel, with double coatings has been evaluated in light microscopy to characterize the defects in each of the coatings. The data found have been fed into the model and the results comply well with reported permeabilities of similar barrier films.</p>

<p>Polymer electrochromism on PEDOT coated fibres was successfully achieved. The electrochromic property of the PEDOT polymer is an excellent property. This feature gives way to many more research works at present and in the future also. The electrochromic property of the PEDOT polymer is utilized in this thesis work to design an electrochromic display pixel.</p><p> </p><p>The polymer coating over the fibres were obtained by using In-situ polymerization technique. The coated-fibres were used to design a display-pixel. Electrochemistry is performed successfully on the designed pixel to study electrochromism over the pixels. An electrochemical fibre transistor is designed successfully using the polymer coated fibres.</p> / Polymer Electrochromism on PEDOT coated fibres

Our goal was to develop a mucoadhesive, oral vaccination delivery platform designed to target Peyer’s patches at ileum. In order to achieve this, we prepared poly(methyl methacrylate) (PMMA) particles of various sizes using W/O/W emulsification solvent evaporation and surface polymerization methods. We then coated and employed mucoadhesive polymers into the carrier system to enhance the residence time in the targeted site. Also we developed our own in vitro mucoadhesion testing ramp as an evaluation tool. Finally, nano- and micro-structured particles were manufactured as two different oral vaccine delivery systems (Solid Lipid Nanoparticles, SLNs; and Protein Coated Microcrystals, PCMC). After the model antigen, bovine serum albumin (BSA) was loaded into the SLNs or PCMC; mucoadhesive polymers were then incorporated and formulated the mixture into pellets. The pellets were then layered with an enteric coating, which was composed of a mixture of Eudragit® FS 30 D/Eudragit® L 30 D-55 for ileum targeted delivery. The in vitro mucoadhesion test ramp was capable of investigating the mucoadhesive properties of tablets and pellets, providing a rank order for study. Most important of all, it was anticipated that this might reduce the burden of testing animals for future proposed mucoadhesive studies. Microcapsules/beads of specific size were manufactured reproducibly by solvent evaporation and surface polymerization. Although we could not specify the cut-off size at the pyloric sphincter in mice, we concluded that the cut-off size at the pyloric sphincter in rats was approximately 2.5-3 mm, which was supported by both the biodistribution data and the direct image results from scintigraphy scanning. Moreover, we found that the particle size significantly alters the gastric emptying time in both rodent models. The small microcapsules/beads were hindered in the folds of the stomach (size 50-100μm for mice and size 0.5-1 mm for rats) and emptied the slowest, followed by the large particles, then the medium particles. Finally, PCMC and SLNs we manufactured were suitable carriers for protein API, such as BSA. These particles were of fitting size for M cell uptake, which would possibly induce mucosal immune responses. Therefore, an antigen containing PCMC and SLNs might be suitable platforms for oral vaccination. / text

The overall objective of the present study was to evaluate the effectiveness of using a variety of hydrophobic biopolymers and hydrophobic biopolymer-coated sands as technically and economically feasible in-situ sediment amendments or alternative capping materials on a laboratory scale. Cutin from tomato peels, cellulolytic enzyme lignin from sitka spruce chips, and keratin azure from commercially dyed sheeps wool were isolated, prepared, tested, and evaluated as feasible hydrophobic biopolymers for the removal of selected Polycyclic Aromatic Hydrocarbons (PAHs). Testing included chemical and physical characterization, as well as the measurement of kinetics and equilibrium sorption parameters for the sorbates naphthalene, phenanthrene, and pyrene as model hydrophobic organic contaminants. Tomato peel cutin exhibited the largest overall affinity for PAHs, however, keratin azure was selected for further evaluation as the most feasible material due to its low preparation cost. Amendment of industrial sand with a stable, uniform, cross-linked keratin azure derivative was achieved to produce hydrophobic biopolymer-coated sand products containing zero, moderate, and high mass fractions of sand. Chemical and physical material parameters, as well as kinetics and equilibrium sorption parameters for the sorbates naphthalene, phenanthrene, and pyrene, were then obtained for the coated sand products. This allowed simple finite difference modeling of PAH fate and transport through a thin cap comprised of the same, insight into the specific sorption mechanisms involved, and information which could prove useful in predicting potential of keratin products to provide a suitable capping material. Conclusions and recommendations for future research focus on the technical and economical feasibility of the prepared hydrophobic biopolymers and hydrophobic biopolymer-coated sand products as capping or in-situ sediment amendments. / text

No description available.

Advanced optical imaging techniques are emerging as useful ways to screen tissues for the presence of cancer. Plasmon resonant nanoparticles have unique optical properties that make them ideal for use as optical contrast agents. The capacity of these particles to serve a multifunctional role dependent on their composition and the intensity of incident light enables them to serve as diagnostic tools and to provide the therapeutic capability of photo-thermal energy conversion or the controlled release of an encapsulated agent. Likewise, the ability to degrade into components of a clearable size may enable the clinical translation of these types of particles.These properties were demonstrated by means of experiments in the support of three specific aims. The first specific aim was to determine whether the unique and tunable optical properties of nanorods lend them to generate signal in advanced optical imaging techniques, and that nanorods can facilitate photo-thermal conversion. The second specific aim was to show that liposomes can serve as a scaffold for the support of an array of gold nanodots to generate a structure that exhibit tunable plasmon resonant characteristics and a resultant ability to generate signal in optical imaging techniques while having the capability to degrade into inert particles of a size that can be readily cleared from the body via the kidney. The final specific aim was to determine whether the gold-coated liposomes of the second specific aim can serve as system for light-based delivery of an encapsulated agent in addition to its role as an optical contrast agent and its biodegradation capacity.Plasmon resonant nanorods and plasmon resonant gold-coated liposomes were generated by reducing free gold from solution onto surfactant coated seed particles and phospholipid liposomes, respectively. Both structures demonstrated the ability to generate signal in optical coherence tomography and in multi-photon confocal microscopy images. Nanorods in high intensity light demonstrate a capacity to mediate photo-thermal energy conversion. While, in similar conditions, gold-coated liposomes are shown to release their contents. Gold-coated liposomes are also shown to degrade to bioinert components of a size reasonable for rapid renal clearance using either surfactant or enzyme.