Objective: Different methods have been suggested to overcome the polymerization shrinkage of composite restorations. Changing the light curing protocol to improve polymerization by using new light curing units is among these methods. The new devices are more efficient, portable and durable and produce less heat. This study aimed to assess the marginal microleakage of class V composite restora...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoelasticity model. The results of the thermo-mechani...

This study investigated the residual tensile properties of plain woven jute fiber reinforced poly(lactic acid) (PLA) during thermal cycling. Temperature ranges of thermal cycling tests were 35-45 °C and 35-55 °C. The maximum number of cycles was 10³ cycles. The quasi-static tensile tests of jute fiber, PLA, and composite were conducted after thermal cycling tests. Thermal mechanical analyses of...

Slow-fast systems on the two-torus T 2 provide new effects not observed for systems on the plane. Namely, there exist families without auxiliary parameters that have attracting canard cycles for arbitrary small values of the time scaling parameter ε. In order to demonstrate the new effect, we have chosen a particularly simple family, namely ẋ = a − cosx − cos y, ẏ = ε, a ∈ (1, 2) being fixed. T...

  Objective: Despite the high strength of zirconia restorations, aging in the oral environment and masticatory loading may result in transformation of tetragonal to monoclinic phase and decrease their strength. Statements in this regard are controversial. This study sought to compare the flexural strength (FS) of Zirkonzahn (ZirkonZahn, Cercon, Ceramill) and Mamut (Dubai Medical Equipment LLC, ...

This contribution presents a friction estimator for industrial purposes which identifies Coulomb friction in a steering system. The estimator only needs a few, usually known, steering system parameters. Friction occurs on almost every mechanical system and has a negative influence on high-precision position control. This is demonstrated on a steering angle controller for highly automated drivin...

The performance of battery electrodes is significantly impacted by chemo-mechanical instabilities at faster charge/discharge rates. This study reports rate-dependent mechanical deformations in the LiFePO4 cathodes during cycling synchronizing situ digital image correlation and electrochemical techniques. electrode undergoes larger early cycles irreversible strains become negligible subsequent c...

The effect of fatigue on ZrCuAl amorphous metals induced by mechanical cyclic loading is investigated using inelastic neutron scattering and the pair density function analysis of neutron diffraction data. With cooling, the local atomic structure undergoes reorganization under fatigue that is directly related to the number of fatigue cycles. Also under fatigue, suppression in the atomic dynamics...

Anode materials of nanostructured silicon have been prepared by physical vapor deposition and characterized using electrochemical methods. The electrodes were prepared in thin-film form as nanocrystalline particles ~12 nm mean diameter! and as continuous amorphous thin films ~100 nm thick!. The nanocrystalline silicon exhibited specific capacities of around 1100 mAh/g with a 50% capacity retent...