''Farmer''s ear'': sudden sensorineural hearing loss due to Chlamydia psittaci infection

Idiopathic dilation of the right atrium (IDRA) is a rare cardiac anomaly of unknown etiology. Whether it is an acquired or congenital lesion is controversial. A case of IDRA detected in utero and confirmed postnatally is reported. The postnatal course was complicated by the development of atrial flutter successfully treated with sotalol. A review of the literature concerning IDRA is presented.     

Electrochemical Pretreatment of Polymers with Dilute Nitric Acid Either Alone or in the Presence of Silver Ions

X-ray Photoelectron spectroscopy (XPS) was used to detect major changes to the surface chemistry of polypropylene (PP), high density polyethylene (HDPE) and styrene-butadiene block copolymer (SBS) caused by electrochemical treatment using dilute nitric acid as electrolyte. Large increases in adhesion levels were observed with PP and HDPE. The method has the potential to be a commercial pretreatment that is inexpensive and safe. Further treatments were carried out in which the complex ion (AgNO₃)⁺ was generated electrochemically. Effective pretreatment was achieved even with dilute solutions (0.001 M w.r.t. silver nitrate). Mechanisms are tentatively proposed for the electrochemical treatment when simply using an electrolyte of dilute nitric acid or where the anolyte consists of a solution of silver nitrate in dilute nitric acid.     

X-ray photoelectron spectroscopy studies of polymer surfaces

The effect of melting polyethylene on aluminium has been re-examined using X-ray photoelectron spectroscopy. Even at 150° C, low and high density polyethylenes show degrees of oxidation similar to that observed with conventional pretreatments; large increases in adhesion are also observed. The results are discussed in relation to transcrystalline regions and weak boundary layers.     

Comments on “X-ray photoelectron spectroscopy studies of polymer surfaces part 2 melting polyethylene against aluminium”

Journal of Materials Science -     

Adhesion Studies of Fluoropolymers

A comparative study of the treatment of polytetrafluoroethylene (PTFE) and poly(vinyl fluoride) (PVF) with “Tetra-Etch” has been carried out. The treatment of PTFE resulted in extensive changes in surface chemistry and topography, whereas with PVF there was no significant change in topography and the chemical changes were much less marked. However, treatment of both polymers resulted in large increases in bond strength.

Multiple bonding experiments in which samples are repeatedly fractured and re-bonded were carried out with untreated PTFE and PVF. These resulted in moderate increases in bond strength with PTFE and large increases with PVF. The results indicate that weak boundary layer (WBL) removal is a key element in adhesion improvement by “Tetra-Etch” on PVF. With PTFE, WBL removal also improves adhesion, but the chemical and/or topographical changes introduced by the “Tetra-Etch” are required for optimum performance.     

An aliphatic amine cured rubber modified epoxide adhesive: 2 Further evaluation

A resin which consists of the product of reacting the diglycidyl ether of bisphenol A with a dicarboxy-terminated butadiene—acrylonitrile copolymer has been evaluated as an adhesive when hardened with di(1-aminopropyl-3-ethoxy) ether and filled with ballotini glass spheres. The resistance of the adhesive to both shear and peel has been examined. Thermomechanical analysis shows the adhesive to have two transition temperatures; this is interpreted in terms of the adhesive consisting of two phases     

A Comparison of Chromate-Phosphate and Chromate-Free Conversion Coatings for Adhesive Bonding

Three different conversion coatings have been evaluated. One of these is an established chromate-phosphate treatment (BONDERITE 705) whilst the others are chromate-free (BONDERITE 777 and EP2472) and not widely used for adhesive bonding. In the present study, the degree of surface modification introduced by these treatments has been determined using Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). Both initial single lap shear and stressed durability results have been obtained using a single part epoxide adhesive. Degreased-only and grit-blasted adherends were used as controls. Overall, the conversion coatings provided better durability performance than the mechanical treatments. The developmental treatment EP2472, a chromate-free conversion coating, out-performed the established chromate-phosphate process at low applied loads (?0.5 kN). All three conversion coatings performed similarly at the higher loads (? 1 kN).     

The interaction of water with an epoxide adhesive based on the diglycidylether of bisphenol-A and triethylene tetramine

The adhesive made by curing the diglycidylether of bisphenol-A and triethylenetetramine demonstrates Fickian uptake from liquid water at temperatures between 4°C and 85°C. Uptake from water vapour at 50°C shows that the diffusion coefficient decreases slightly with concentration. The vapour uptake equilibria are examined using the Zimm clustering theory and the Flory-Huggins lattice model and these support the view that the water absorbed by the adhesive forms clusters.