In the present research, thixoforming route was carried out in order to enhance the microstructural features of LM28 piston alloy. Typical microstructure of this alloy was composed of coarse, polygonal primary silicon particles, eutectic matrix and intermetallic phases. Thermal analysis was carried out to study the solidification path of the base alloy and determine the major arrest temperature...

OBJECTIVE Oxidative stress and NO are thought to play important roles in arteriosclerosis pathogenesis, a major cause of white matter lesions in the brain. Therefore, we examined whether NO metabolites (NOx) and 8-iso-prostaglandin F(2alpha) (IsoP) levels in vivo correlated with the severity of periventricular hyperintensity (PVH) to evaluate potential roles of oxidative stress and NO in white ...

The objective of this study was to compare the low temperature degradation (LTD) behavior of femoral heads made of 3Y-TZP as observed on retrievals with that induced in vitro upon prolonged exposures to a hydrothermal environment. The time-dependent evolution of tetragonal-to-monoclinic transformation and the related residual stresses were nondestructively monitored by Raman microspectroscopy. ...

beta-Adrenergic receptor (beta-AR)-mediated (cAMP-dependent) vasorelaxation declines with advancing age. It has been shown that angiotensin II (ANG II), a potent vasoconstrictor, enhances cAMP-mediated vasorelaxation. Therefore, we questioned whether ANG II could reverse age-related, impaired beta-AR-mediated vasorelaxation and cAMP production. Pretreatment of aortic rings from 6-wk-old or 6-mo...

the clinical and economic importance of heart failure is widely recognized.   the incidence of heart failure is on the increase, particularly with the aging of the population around the world.   it is time for a paradigm shift in heart failure management. alternative non-pharmacological strategies to remodel the failing ventricle will shape a major portion of heart failure therapy in the decade...

Methodology for the evaluation of long-term thermal performance of cellular plastics is being developed under a collaboration of North American foam industry with the National Research Council of Canada. The mechanism of this collaboration includes a joint research project between the Society of Plastics Industry and the NRC Canada. To evaluate long-term thermal performance (LTTP) of cellular p...

This in vitro study investigated the aging behavior of dental composites with regard to surface roughness (SR), Vickers hardness (VH) and flexural strength (FS), and the study elucidated the impact of artificial aging parameters. One hundred and sixty-five rectangular specimens were prepared from five composites (Filtek Supreme XT, Filtek Silorane, CeramX, Quixfil, experimental ormocer) and sub...

  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, ...

Policymakers regularly implement stricter building energy-efficiency codes towards curtailing energy use. Inevitably, super-insulating materials such as Vacuum Insulation Panels (VIPs) are essential to satisfy codes. VIPs have been applied buildings for over two decades now, with many lessons learned. Generally, the thermal conductivity values of often reported in literature center-of-panel (λc...

The influence of a typical prooxidative additive, cobalt stearate, on the thermal stability, degradation kinetics and lifetime of low-density polyethylene (LDPE) was investigated using non-isothermal thermogravimetric analysis (TGA) in both nitrogen and air atmosphere. The derivative thermogravimetric (DTG) curves indicate single stage and multistage decomposition process in nitrogen and air at...