The aging correlation (RH + t): Relative humidity (%) + temperature (deg C)

An aging correlation between corrosion lifetime, and relative humidity RH (%) and temperature t (C) has been reported in the literature. This aging correlation is a semi-log plot of corrosion lifetime on the log scale versus the interesting summation term RH(%) + t(C) on the linear scale. This empirical correlation was derived from observation of experimental data trends and has been referred to as an experimental law. Using electrical resistivity data of polyvinyl butyral (PVB) measured as a function of relative humidity and temperature, it was found that the electrical resistivity could be expressed as a function of the term RH(%) t(C). Thus, if corrosion is related to leakage current through an organic insulator, which, in turn, is a function of RH and t, then some partial theoretical validity for the correlation is indicated. This article describes the derivation of the term RH(%) t(C) from PVB electrical resistivity data

Photovoltaic Module Encapsulation Design and Materials Selection, Volume 1, Abridged

A summary version of Volume 1, presenting the basic encapsulation systems, their purposes and requirements, and the characteristics of the most promising candidate systems and materials, as identified and evaluated by the Flat-Plate Solar Array Project is presented. In this summary version considerable detail and much supporting and experimental information has necessarily been omitted. A reader interested in references and literature citations, and in more detailed information on specific topics, should consult Reference 1, JPL Document No. 5101-177, JPL Publication 81-102, DOE/JPL-1012-60 (JPL), June 1, 1982

Encapsulant selection and durability testing experience

The Flat Plate Solar Array Project (FSA) has established technically challenging cost and service life goals for photovoltaic modules. These goals are a cost of $70 sq m and an expected 30 years of service life in an outdoor weathering environment. out of the cost goal,$14 sq m is allocated for encapsulation materials, which includes the cost of a structural panel. At FSA's inception in 1975, the cumulative cost of encapsulation materials in popular use, such as room temperature vulcanized (RTV) silicones, aluminum panels, etc., greatly exceeded $14/sq m. Accordingly, it became necessary to identify and/or develop new materials and new material technologies to achieve the goals. Many of these new materials are low cost polymers that satisfy module engineering and encapsulation processing requirements but unfortunately are not intrinsically weather stable. This necessitates identifying lifetime and/or weathering deficiencies inherent in these low cost materials and developing specific approaches to enhancing weather stability

Paula Kane Studio Wall

Paula Kane Studio Wall was produced as part of 'How Art Thinks', a collaborative project engaging with artists' practice and process. It brings together notes and images relating to the artist’s Studio Wall project, in which Kane exhibited a wall-mounted assemblage of evidence that also functioned as an artwork in its own right. It has been designed as a visual record of the artist’s process, enabling the readerviewer to find a path through the work, supplemented by responsive essays from painter Mikey Cuddihy and critic Ian Heywood. The book is the first in a series produced by the International Centre for Fine Art Research at UAL as part of the research project How Art Thinks. The project takes artist’s publication as one of several sites of creative and critical enquiry, providing insight into the visual, material and intellectual processes of making. It aims to find creative ways to document artists’ decision-making processes, as well as listening and responding to artists’ narratives

On rate-dependent polycrystal deformation: the temperature sensitivity of cold dwell fatigue

A temperature and rate-dependent crystal plasticity framework has been used to examine the temperature sensitivity of stress relaxation, creep and load shedding in model Ti-6Al polycrystal behaviour under dwell fatigue conditions. A temperature close to 120°C is found to lead to the strongest stress redistribution and load shedding, resulting from the coupling between crystallographic slip rate and slip system dislocation hardening. For temperatures in excess of about 230°C, grain-level load shedding from soft to hard grains diminishes because of the more rapid stress relaxation, leading ultimately to the diminution of the load shedding and hence, it is argued, the elimination of the dwell debit. Under conditions of cyclic stress dwell, at temperatures between 20°C and 230°C for which load shedding occurs, the rate-dependent accumulation of local slip by ratcheting is shown to lead to the progressive cycle-by-cycle redistribution of stress from soft to hard grains. This phenomenon is termed cyclic load shedding since it also depends on the material's creep response, but develops over and above the well-known dwell load shedding, thus providing an additional rationale for the incubation of facet nucleation

Method of making hollow elastomeric bodies

Annular elastomeric bodies having intricate shapes are cast by dipping a heated, rotating mandrel into a solution of the elastomer, permitting the elastomer to creep into sharp recesses, drying the coated mandrel and repeating the operation until the desired thickness has been achieved. A bladder for a heart assist pump in which a cylindrical body terminating in flat, sharp horizontal flanges fabricated by this procedure has been subjected to over 2,500 hours of simulated life conditions with no visible signs of degradation

Antisoiling technology: Theories of surface soiling and performance of antisoiling surface coatings

Physical examination of surfaces undergoing natural outdoor soiling suggests that soil matter accumulates in up to three distinct layers. The first layer involves strong chemical attachment or strong chemisorption of soil matter on the primary surface. The second layer is physical, consisting of a highly organized arrangement of soil creating a gradation in surface energy from a high associated with the energetic first layer to the lowest possible state on the outer surfce of the second layer. The lowest possible energy state is dictated by the physical nature of the regional atmospheric soiling materials. These first two layers are resistant to removal by rain. The third layer constitutes a settling of loose soil matter, accumulating in dry periods and being removed during rainy periods. Theories and evidence suggest that surfaces that should be naturally resistant to the formation of the first two-resistant layers should be hard, smooth, hydrophobic, free of first-period elements, and have the lowest possible surface energy. These characteristics, evolving as requirements for low-soiling surfaces, suggest that surfaces or surface coatings should be of fluorocarbon chemistry. Evidence for the three-soil-layer concept, and data on the positive performance of candidate fluorocarbon coatings on glass and transparent plastic films after 28 months of outdoor exposure, are presented

What Am I?

This autobiographical work revolves around the author\u27s personal identity and how she sorts through various stories of her family\u27s heritage. Cuddihy is able to relate her family stories to her own life and connect them to resonant themes of American identity. The development of the author\u27s family over the years has granted her the opportunity to attend a four-year university today

Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume VII: Module encapsulation

The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. The objective of the Encapsulation Task was to develop, demonstrate, and qualify photovoltaic (PV) module encapsulation systems that would provide 20-year (later increased to 30-year) life expectancies in terrestrial environments, and which would be compatible with the cost and performance goals of the FSA Project. The scope of the Encapsulation Task included the identification, development, and evaluation of material systems and configurations required to support and protect the optically and electrically active solar cell circuit components in the PV module operating environment. Encapsulation material technologies summarized in this report include the development of low-cost ultraviolet protection techniques, stable low-cost pottants, soiling resistant coatings, electrical isolation criteria, processes for optimum interface bonding, and analytical and experimental tools for evaluating the long-term durability and structural adequacy of encapsulated modules. Field testing, accelerated stress testing, and design studies have demonstrated that encapsulation materials, processes, and configurations are available that will meet the FSA cost and performance goals. Thirty-year module life expectancies are anticipated based on accelerated stress testing results and on extrapolation of real-time field exposures in excess of 9 years

Improving phylogenetic inference of protein evolution through a structurally constrained protein evolution model based on torsional normal modes

Trabajo Fin de Máster en Bioinformática y Biología ComputacionalAims: The goal of this project is to develop and test a new method for predicting the change of a known protein structure produced by a given amino acid mutation. This prediction consists of two parts: (1) Modelling the perturbation induced by the mutation, which was done in the host laboratory and whose parameters the present work aims to determine; and (2) Computing the structural change produced by this perturbation as the linear response of the protein, as suggested by the structurally constrained model of protein evolution developed by Julián Echave. For this second part the Torsional Network Model (TNM) developed in the host laboratory was applied. The grand-goal is to predict the fitness change associated with the mutation and integrate it with the Stability Constrained models of Protein Evolution model previously developed in the host lab to improve phylogenetic inference of protein evolution. In this work, predicted and observed structural changes and RMSD are used to determine optimal parameters on a training set and assess the model on a test set. Method: A set of protein pairs differing in one mutated amino acid were used for this project. Several filters were applied to ensure, as far as possible, that the observed structural change was mainly due to the mutation. For instance, the structures must contain the same ligands in order to reduce the possibility that the structural change arises from ligand binding. Proteins were divided into a training set and a test set. Three mutation parameters were optimized using Jarratt’s method of successive parabolic interpolation to minimize the error of the predicted RMSD of the training set. Results: The initial results suggested that overfitting was taking place and that it was necessary to regularize the optimization by imposing an additional condition on the direction of the structural change. The regularized parameters avoided unrealistic negative parameters, improved the prediction of the direction of the structural change and yielded an acceptable error on the predicted RMSD of the test set. Conclusion: The optimized parameters produced acceptable results, although the regularization could be further improved with additional work