costs and train operations. The impact is sometimes magnified by imperfect or poorly understood techniques for predicting and detecting IJ failures. A common factor in many failures of bonded IJs is a tendency for the epoxy to come debonded from the rail or joint bar near the center of the joint (2). The debonded region starts small but grows with time and traffic, spreading outward toward the ...

Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarbo...

The production of antibacterial and antifungal nanocomposites is widely usedin pharmaceutical, health, food, packaging and medical industries. Meanwhile,the epoxy coating film is one of the most commonly used protective coatings inindustrial applications. In this work, ZnO nanoparticles were first synthesized atthree different concentrations. UV-Vis spectroscopy and dyna...

Background: Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m–3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by resi- dential radon exposure.Objective: This study aims at investigating the ef...

Combining several materials to create a structural system has led to a new kind of application previously not possible with conventional materials. Examples are FRP and its strengthening system. Nonetheless, the existence of the interface between two substrates introduces a challenging problem in determining durability of bond systems. In many applications, the durability of individual material...

In this research work, impact strength of untreated, alkali treated, potassium permanganate treated, benzoyl chloride treated and acrylic acid treated areca fiber reinforced epoxy composites were studied under 40%, 50%, 60% and 70% fiber loadings. Impact strength increased with increase in fiber loading up to 60% and then showed a decline for all untreated and chemically treated areca fiber rei...

A new method for preparing SWNT/epoxy nanocomposites has been developed which involves high shear mixing of the epoxy resin and SWNT and heat treating the mixture prior to introducing the hardener. The glass transition temperature of the epoxy resin is unaffected by the presence of nanotubes. An improvement of 17% in flexural modulus and 10% in flexural strength has been achieved at 0.05 wt% of...

BACKGROUND Epoxy products are among the most common causes of occupational allergic contact dermatitis. Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most important sensitizer in epoxy systems. OBJECTIVES To describe patients with occupational allergic contact dermatitis caused by epoxy products. METHODS Patients with allergic reactions to epoxy chemicals were chosen from test file...

in the present research work, the flexural modulus and strength of glass fiber-epoxy resin and carbon fiber-epoxy resin composites have been enhanced through fiber tension during curing of the polymeric resin. this study showed that the tension applied on the fibers increased the flexural modulus of the glass-epoxy composites up to 12% and the flexural strength up to 19%. the flexural modulus a...