objectives: the aim of this study was to assess and compare the water sorption and flexural strength of thermoplastic and conventional acrylic resins. materials and methods: water sorption and flexural strength were compared between a thermoplastic modified polymethyl methacrylate (pmma) denture base resin (group a) and a heat-polymerized pmma acrylic resin (group b) as the control group (n=10)...

TThis study investigated the water absorption of chitosan, collagen, and chitosan/collagen blend membranes exposed to gamma-ray irradiation. These membranes were produced via the solvent evaporation method. All membranes then underwent irradiation at 15 or 25 kGy gamma-ray doses, while membranes without irradiation were used as controls. After immersing the membranes in distilled water for up t...

Mercury has long been recognised as a neurotoxin element for many decades and with its compounds being extremely toxic, is ranked third in the ‘priority list of hazardous substance’ by the United States comprehensive environmental response, compensation, and liability act. In different samples, mercury can exist as either its inorganic or organic forms and this paper will review the methods for...

in this research, water and steam absorption behavior and also effect of maleic anhydride polypropylene (mapp) on these behaviors in wood fiber-polypropylene composite were compared. for this purpose, the composites were manufactured from 60% fibers and 40% polypropylene in presence and absence of ma. the oven dried samples with dimensions of 2.5×2.5×1 cm were immersed in distilled water and ex...

hydrothermal treatment of wood material products with many interesting properties such as enhanced dimensional stability, lower equilibrium moisture content and increased biological durability. the effects of hydrothermal treatment on dimensional stability, oven dry density and water absorption of beech wood (fagus orientalis) naturally grown, has been studied in present research that extremely...

nanocomposites based on polyamide 6/polypropylene  )pa6/pp 67/33) blend containing 2.5 to 10 phr of nano-caco3  and 5 phr of maleated polypropylene )pp-g-mah) as compatibilizer were prepared by melt compounding followed by injection molding. the mechanical properties, water absorption, as well as shrinkage behavior were characterized and the morphology was studied using scanning electron micros...

an efficient, rapid, simple, and highly selective dispersive liquid–liquid microextraction basedon solidification of floating organic drop (dllme-sfod), combined with flame atomicabsorption spectrometry was developed for preconcentration and determination of trace amountsof cobalt in water samples. in this method, an appropriate mixture of acetone and1-undecanol was injected rapidly into the aq...

a simple, highly sensitive, accurate and selective method for determination of trace amounts of cu2+ in water samples .in this paper, chitosan was used to encapsulate nano-fe3o4 and produce a nano-fe3o4-chitosan sorbent based new sorbent was prepared. this was treated with ethylenediamine (ed) in another solvent-free procedure for the formation of a novel nano-fe3o4-chitosan-ed.flame atomic abs...

heavy metals are highly poisonous in the environment, even in small quantities, and endanger certain species and all live beings. current methods of removing heavy metals from aqueous media include chemical sequestration, ion exchange, surface absorption, membrane processes, oxidation and revival procedures which have high investment and exploitation costs. hence, it is significantly necessary ...

objective: to measure the long-term linear hygroscopic expansion (lhe) of several materials using bulked and layered techniques. materials and methods: seven materials were used; fuji cap ii, fuji ii lc, photac-fil aplicap, vitremer, dyract, tetric and z100. ten specimens (6×4 mm) were made for each material using layered and bulked techniques (each group comprises five specimens). the specimen...