The effects of mixtures Ni–Ta and Ni–Zr powders combined with sintered solid solution TaB2 –NbC during spark-plasma sintering compositions at a pressing loading 60 MPa in the range 1200 – 1600°C on phase composition, percent content Ti, Ta, Zr sialon; microstructure; grain sizes crystalline phases; relative density; linear shrinkage; physical-mechanical properties; correlation elasticity modulu...

nasoohi n 1 hoorizad m1 torabzadeh tari n 2   1- assistant prof, department of operative dentistry, islamic azad university, dental branch, tehran,iran   2-dentist   corresponding author : nasoohi n: department, no 4, 10th neyestan ave, pasdaran, tehran   tel : 09125392175 email: [email protected]     background and aim: discoloration of dental composites is one of the major reasons of the...

composite pressure vessel cng made of epoxy – carbon material with nonmetal liner is 60% lighter than aluminum vessel under the same conditions. one of the important parameters in the pressure vessels design is their resistance against impact and prevention of explosion. in this paper, the effects of low velocity impact on composite pressure vessel are investigated using fe analysis. the vessel...

to evaluate the ultimate compressive strength of five composite resins after 1 hour, 24 hours, 7 days and 1 month. twenty four cylindrical 4 mm×8mm specimens of each commonly used composite resins in posterior region (nulite-f , z250 , p60, biscore, tetric ceram hb) were prepared. each group of composite resins were divided into four time groups of 1 h, 24 h, 7 days and 1 month. all of specimen...

introduction: although composite resins have improved greatly since their introduction, microleakage is one of the most frequently encountered problems. this study compared the effects of different monomer systems and layering techniques on the bacterial leakage of cl i composite resin restorations. methods: eighty-two sound human third molars were used. the teeth were randomly divided into six...