in the present research, nonlinear vibration in a coupled system of boron-nitride nano-tube reinforced composite (bnntrc) oil pipes is studied. single-walled boron-nitride nano-tubes (swbnnts) are arranged in a longitudinal direction inside poly-vinylidene fluoride (pvdf) matrix. damping and shearing effects of surrounded medium are taken into account by visco-pasternak model. based on piezoele...

The plate of a pultruded fiber-reinforced polymer or fiber-reinforced plastic (FRP) profile produced via a pultrusion process is likely to undergo local buckling and cracking along the fiber direction under an external load. In this study, we constructed a pultruded glass-fiber-reinforced polymer-light wood composite (PGWC) profile to explore its mechanical performance. A rectangular cross-sect...

AIM Restoring endodontically treated teeth is one of the major treatments provided by the dental practitioner. Selection and proper use of restorative materials continues to be a source of frustration for many clinicians. There is controversy surrounding the most suitable choice of restorative material and the placement method that will result in the highest probability of successful treatment....

in this research, static stresses analysis of boron nitride nano - tube reinforced composite (bnntrc) cylinder made of poly - vinylidene fluoride (pvdf) subjected to non - axisymmetric thermo - mechanical loads and applied voltage is developed. the surrounded elastic medium is modelled by pasternak foundation. composite structure is modeled based on piezoelectric fiber reinforced composite (pfr...

There have been great developments in the area of civil engineering in the recent few decades and among these, construction and material innovation are quite prominent. Steel-concrete composite construction has emerged as one of the fastest methods of construction. Even though considerable research efforts on conventional reinforced concrete columns have been executed prior to now, concrete fil...

PURPOSE This study aimed to assess the long-term survival rates of polyethylene fiber-reinforced posts and cores used in endodontically treated teeth over a 97-month period. MATERIALS AND METHODS Sixty-nine patients from a private dental office who underwent endodontic treatment with coronoradicular fiber-reinforced restorations were selected and invited for evaluation. All teeth were restore...

objective: reinforcement with fiber is an effective method for considerable improvement in flexural properties of indirect composite resin restorations. the aim of this in-vitro study was to compare the transverse strength of composite resin bars reinforced with preimpregnated and non-impregnated fibers. materials and methods: thirty six bar type composite resin specimens (3×2×25 mm) were const...

OBJECTIVE The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. METHODS Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (pe...

Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution to the rational design of highly functional synthetic ECM ...

The purpose of this study was to use a tape casting technique to develop an Al2O3 fiber-reinforced Al2O3-based ceramic material (Al2O3-fiber/Al2O3 composite) into a new type of dental ceramic. The Al2O3-based ceramic used a matrix consisting of 60 wt% Al2O3 powder and 40 wt% SiO2-B2O3 powder. The prepreg sheets of Al2O3-fiber/Al2O3 composite (in which uniaxially aligned Al2O3 fibers were infilt...