Design for Survival: Sustainability for Planet and Structure

Buildings in Port Aransas encounter drastic environmental challenges: the potential catastrophic storm surge and high winds from a hurricane, and daily conditions hostile to buildings, vehicles, and even most vegetation. Its location a few hundred feet from the Gulf of Mexico and near-tropical latitude expose buildings to continuous high humidity, winds laden with scouring sand and corrosive salt, and extremes of temperature and ultraviolet light. Building construction methods are able to address each of these, but doing so in a sustainable way creates significant challenges. The new research building at the Marine Science Institute has been designed and is being constructed to meet the demand for both survivability and sustainability. It is tracking towards formal certification as a LEED Gold structure while being robust and resistant to the harsh coastal environment. The effects of a hurricane are mitigated by elevating buildings and providing a windproof envelope. Ground-level enclosures are designed to be sacrificial and non-structural so they can wash or blow away without imposing damage on the upper portions of the building, and only non-critical functions and equipment will be supported within them. Design features that integrate survivability with sustainability include: orientation of building axis; integral shading from direct summer sunlight; light wells; photovoltaic arrays; collection of rainwater and air conditioning condensate for use in landscape irrigation; reduced impervious cover; xeriscaping and indigenous plants; recycling of waste heat from air conditioning systems; roofing system that reflects light and heat; long life, low maintenance stainless steel, high-tensile vinyl, hard-anodized aluminum and hot-dipped galvanized mountings throughout; chloride-resistant concrete; reduced visual impact; recycling of construction materials.

Spectroscopic properties of neodymium doped high silica glass and aluminum codoping effects on the enhancement of fluorescence emission

Nd3+ -codoped and Al3+-Nd3+-codoped high silica glasses have been prepared by sintering nanoporous glasses impregnated with Nd3+ stop and Al3+ ions. The Judd-Ofelt intensity parameters Omega(2,4,6) of Nd3+-doped high silica glasses were obtained and used to analyze aluminum codoping effects. Fluorescence properties of Nd3+-doped high silica glasses strongly depend on the Al3+ concentration. While Nd3+ ion absorption and emission intensities of obviously increase when aluminum is added to Nd3+-doped high silica glasses, fluorescence lifetimes decrease and aluminum codoping has almost no influence on the radiative quantum efficiencies. This indicates that aluminum codoping is responsible for an anti-quenching effect through a local modification of rare-earth environments rather than through physical cluster dispersion.

Nano-polypyrrole supercapacitor arrays prepared by layer-by-layer assembling method in anodic aluminum oxide templates

A novel method for preparing nano-supercapacitor arrays, in which each nano-supercapacitor consisted of electropolymerized Polypyrrole (PPy) electrode / porous TiO2 separator / chemical polymerized PPy electrode, was developed in this paper. The nano-supercapacitors were fabricated in the nano array pores of anodic aluminum oxide template using the bottom-up, layer-by-layer synthetic method. The nano-supercapacitor diameter was 80 nm, and length 500 nm. Based on the charge/discharge behavior of nano-supercapacitor arrays, it was found that the PPy/TiO2/PPy array supercapacitor devices performed typical electrochemical supercapacitor behavior. The method introduced here may find application in manufacturing nano-sized electrochemical power storage devices in the future for their use in the area of microelectronic devices and microelectromechanical systems.

Effect of chloride ions' introduction on structural, thermal stability, and spectroscopic properties in Yb3+Er3+-codoped germanate-bismuth-lead glasses

Yb3+Er3+-codoped chloride-modified germanate-bismuth-lead glasses have been synthesized by the conventional melting and quenching method. Structural and thermal stability properties have been obtained on the basis of the Raman spectra and differential thermal analysis, which indicate that the PbCl2 addition has an important influence on the phonon density of states, maximum phonon energy, and thermal stability of host glasses. The Judd-Ofelt intensity parameters and quantum efficiencies were calculated on the basis of the Judd-Ofelt theory and lifetime measurements. For the 1.53 mu m emission band, the full widths at the half-maximum increase and peak wavelengths are blueshifted with increasing PbCl2 content. Moreover, the effect of the PbCl2 addition on the phonon density of states, OH- content, and upconversion luminescence has been discussed and evaluated. Our results reveal that, with increasing PbCl2 content, the decrease of phonon density and OH- content contributes more to the enhanced upconversion emissions than that of maximum phonon energy. (c) 2005 Optical Society of America

Comparative investigation of up-conversion luminescence in Tm3+-doped oxide-chloride germanate and tellurite glasses

Tm3+-doped oxide-chloride germanate and tellurite glasses have been synthesized by conventional melting method. Intense up-conversion luminescence emissions were simultaneously observed at room temperature in these glasses. The possible up-conversion mechanisms are discussed and estimated. However, in these Tm3+-doped glasses, tellurite glass showed weaker up-conversion emissions than germanate glass, which is inconsistent with the prediction from the difference of maximum phonon energy between tellurite and germanate glasses. In this paper, Raman spectroscopy was employed to investigate the origin of the difference in up-conversion luminescence in the two glasses. Our results confirm that, besides the maximum phonon energy, the phonon density of host glasses is also an important factor in determining the up-conversion efficiency. (c) 2005 Elsevier Ltd. All rights reserved.

Effects of chloride substitution on the chemical and physical properties and the crystallization behavior in heavy metal fluoride glasses

Effect of the substitutions of chloride for fluoride on the chemical and physical properties and the crystallization behavior in heavy metal fluoride glasses has been investigated. The characteristic temperature of the glass does not changed obviously when the fluoride was taken place by chloride. Compared with samples of being free of ErF3, the doping samples are more inclined to be surface crystallization. Optical basicity in the glass system increases with increasing the negative charge provided by the chloride atoms and the absorption peak red shifted is observed in absorption spectra. XRD measurements show that not a single crystalline phase appears in the heated glass samples, which indicate the substitutions of chloride for fluoride with a variety of crystalline precipitation trends. (c) 2007 Elsevier B.V All rights reserved.

Upconversion luminescence in Yb3+-doped yttrium aluminum garnets

In this paper, we present results on upconversion luminescence performed on Yb3+-doped yttrium aluminum garnets under 940 nm excitation. The upconversion luminescence was ascribed to Yb3+ cooperative luminescence and the presence of rare earth impurity ions. The cooperative luminescence spectra as a function of Yb concentration were measured and the emission intensity variation with Yb concentration was discussed. Yb3+ energy migration quenched the cooperative luminescence of Yb:YAG crystals with doping level over 15 at%. (c) 2004 Elsevier B.V. All rights reserved.