The general problem of nonlinear wrinkling of nonlinear membranes of revolution is considered. The theory is applicable to membranes made of any nonlinear material although only Mooney material is considered in this paper. A smooth psuedo deformed surface is introduced to give a gross representation of the true deformed surface, and a kinematic quantity called wrinkle strain is introduced to measure the wrinklyness of the surface. The wrinkly regions are determined by the usual assumption that a thin membrane cannot take any compressive stress. A stretching problem is solved as an example.

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Three combinations of additives based on polyethylene glycol (PEG), Cl − ions, bis(3-sulfopropyl)disulfide (SPS), and Alcian Blue (ABPV) were used to fabricate the Cu plated layer. The additive combination was found to play an important role in the microstructural evolution of the Cu plated layer. The PC (PEG + Cl − ) case produced the Cu plated layer with grains of a smaller size and random morphology, while the PCS (PEG + Cl − + SPS) and PCSA (PEG + Cl − + SPS + ABPV) cases produced the Cu plated layers with grains of a larger size and faceted morphology. Experimental results based on metallurgical examination and trace element analysis indicated that the interfacial reactions between Sn and Cu plated layers strongly depended upon the additive combination used in the Cu plating solution, and the dependence was reasonably correlated with the grain morphology of the Cu plated layer combined with the incorporation of organic impurities.Cu is commonly used for conductors and metallizations in printed circuit board (PCB) and Si integrated-circuit (IC) chip due to its superior electrical conductivity and good wettability with solder materials. Sn is extensively used in microelectronic solders due to its suitable melting point, efficient mechanical property, and low cost. So, the Sn/Cu joints massively exist in the microelectronic products. To form a Sn/Cu joint, reflow is conducted during which the Sn melts and wets the Cu substrate. The intermetallic compounds (IMC) are usually formed as a result of the interfacial reaction between Sn and Cu. Related investigations have been extensively performed to provide helpful information for reliability evaluation of solder joints. [1][2][3][4][5][6][7] The Cu conductor and metallization on PCB and Si chip can be fabricated using various methods, among which electroplating is widely used due to economic consideration. Electroplating is an electrochemical process involving complicated interaction between various additives used in the Cu plating bath, such as suppressor, accelerator, and so on. These additives interacted with each other on the Cu surface and inevitably were partially incorporated into the Cu plated layer during electroplating. The incorporation of organic impurities in the Cu plated layers during plating was found to have significant effects on the interfacial reactions between Sn-based solder and Cu plated substrate. [8][9][10][11][12][13] The S residue of about 17 ppm was detected in the Cu plated layer when a high level (3 × 10 −5 M) of accelerator, SPS (bissodium sulfopropyldisulfide, C 6 H 12 O 6 S 4 Na 2 ), was added in the Cu plating bath. 8 Large amounts of void were formed at the Cu/Cu 3 Sn interface along with the solder/Cu interfacial reaction during 150 • C aging, which was attributed to the reduction of free energy barrier for void formation due to interfacial segregation of S. Voids were continuously formed during aging and merged into several gaps within the Cu-Sn IMCs, forming an alternating layered structure composed of gaps and IMCs at the Sn-3...

This paper summarizes current research aimed at using polymer materials for glazing and heat exchanger components in solar water heating systems. Functional requirements, relevant polymer properties and an approach for selecting polymers are described for each of these components. Glazing must have high transmittance across the solar spectrum and withstand long term exposure to ultraviolet (UV) light. Candidate glazing materials were tested outdoors for one year in Golden, Phoenix and Miami, as well as exposed for over 300 days in an accelerated testing facility at a concentration ratio of two at the National Renewable Energy Laboratory. Measurements of hemispherical transmittance indicate that a 3.35 mm polycarbonate sheet with a thin film acrylic UV screen provides good transmittance without excessive degradation. The primary challenge to designing a polymer heat exchanger is selecting a polymer that is compatible with potable water and capable of withstanding the high pressure and temperature requirements of domestic hot water systems. Polymers certified for hot water applications by the National Sanitation Foundation or currently used in heat exchangers and exhibit good high temperature characteristics were compared on the basis of a merit value (thermal conductance per unit area per dollar) and manufacturer’s recommendations. High temperature nylon (HTN), polypropylene (PP) and cross linked polypropylene (PEX) are recommended for tube components. For structural components (i.e. headers), glass reinforced high temperature nylon (HTN), polyphthalamide (PPA), polyphenylene sulphide (PPS) and polypropylene (PP) are recommended. [S0199-6231(00)00902-3]

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