preparation and uses of quinaldinium dichromate and its polymeric analogue poly (2- vinylquinolinium) dichromate as the new monomeric and polymeric oxochromium-amine complex reagents for oxidizing variousorganic compounds, with emphasis on the latter, are described

there is a worldwide interest in using fibers of different types in concrete mixtures. in this regard, as the use of pet fibers has gradually increased during the last decade, this study aims to investigate the effects of pet fibers on the mechanical properties of hardened concrete and the workability of fresh concrete. to this end, different contents of pet fibers (pc= %0, %0.5, %1 and %1.5) a...

one of the main factors of premature deterioration of concrete structures is the corrosion of reinforcements. chloride penetration of concrete is one of the main reasons of this phenomenon. therefore, to have durable structure, it is necessary to have concretes with low permeability.there are various methods to evaluate permeability of concrete. finding a relationship between them can be useful...

Herein we report preparation of polymeric monofunctional nanoparticles (PMNs) through intramolecularly cross-linking the polymer chains sparsely grafted on the surface of sacrificial silica spheres, and a one-to-one coupling reaction between PMNs and linear polymer chains and that between two PMNs.

Ductile fiber-reinforced cement-based composites (DFRCCs) are being investigated for new design as well as retrofitting of structures in seismic regions. DFRCC is highly ductile and is characterized by strain-hardening in tension to strains over 3% and by unique cyclic loading behavior. To accurately predict the structural performance of DFRCC components under cyclic and seismic loading, a robu...

By increasing the demolition of old concrete structures and the interest of civil industries to consume cheaper materials, using Recycled Concrete Aggregate (RCA) can cause environmental protection and decrease the construction costs. On the other hand, the high potential of Recycled Aggregate Concrete (RAC) in concrete industry was established by extensive experimental researches were performe...

In this article various pipes used for transporting of gas are introduced and pros and cons of each one are elucidated. The pipes are categorized in three different subgroups including metallic, polymeric and metallic-wire reinforced polymeric pipes. Metallic-wire reinforced polymeric pipes are nominated as the best option for usage in high pressure pipelines transporting natural gas. As a resu...

A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stresshtrain...

Steel is one of the most used materials in civil construction and, although it exhibits a very satisfactory performance terms mechanical properties, has disadvantage susceptibility to tribochemical mechanisms. Corrosion steel reinforced concrete structures (Standard NBR 7480 - CA50) can affect its structural integrity, decreasing resistance external stresses, affecting service life therefore, d...

in recent years, utilization of chitosan /tripolyphosphate nanoparticles has been considered greatly as protein delivery vehicles. effects of a variety of factors on final characteristics of nanoparticles have been studied by many investigators. although, the objective of this study was to achieve smaller chitosan nano carriers via changing fabrication parameters such as ph and temperature and ...