Crack growth resistance (R-curve) behaviour and thermo-physical properties of Al<SUB>2</SUB>O<SUB>3</SUB> particle-reinforced AlN/Al matrix composites

Crack growth resistance behaviour and thermo-physical properties of Al2O3 particle-reinforced AlN/Al matrix composites have been studied as a function of AlN volume fraction as well as Al2O3 particle size. The fracture toughness of the composites decreased with increase in vol% AlN and decrease in Al2O3 particle size. All the composites exhibited R-curve behaviour which has been attributed to crack bridging by the intact metal ligaments behind the crack tip. The Young's modulus of the composites increased with the vol% of AlN whereas the thermal diffusivity and coefficient of thermal expansion followed a reverse trend. The composites exhibited hysteresis in thermal expansion as a function of temperature and the hysteresis decreased with decrease in metal content of the composite

Crack growth resistance (R-curve) behaviour and thermo-physical properties of Al2O3Al_2O_3 particle-reinforced AlN/Al matrix composites

Crack growth resistance behaviour and thermo-physical properties of $Al_2O_3$ particle-reinforced AlN/Al matrix composites have been studied as a function of AlN volume fraction as well as $Al_2O_3$ particle size. The fracture toughness of the composites decreased with increase in vol% AlN and decrease in $Al_2O_3$ particle size. All the composites exhibited R-curve behaviour which has been attributed to crack bridging by the intact metal ligaments behind the crack tip. The Young’s modulus of the composites increased with the vol% of AlN whereas the thermal diffusivity and coefficient of thermal expansion followed a reverse trend. The composites exhibited hysteresis in thermal expansion as a function of temperature and the hysteresis decreased with decrease in metal content of the composite

Mutagenicity and Acute Oral Toxicity Test for Herbal Poultry Feed Supplements

Herbal products are being used and trusted globally for thousands of years for their health benefits and limited side effects. Globally, a general belief amongst the consumers is that herbal supplements are always safe because they are “natural.” But later, research reveals that they may not be safe. This raises concern on their safety and implications for their use as feed supplement or medicine. Toxicity testing can reveal some of the risks that may be associated with use of herbs, therefore avoiding potential harmful effects. The present study was designed to investigate five poultry feed supplements (PFS), EGMAX® (to revitalize ovarian activity), FEED-X™ (feed efficiency enhancer), KOLIN PLUS™ (natural replacer of synthetic choline chloride), PHYTOCEE® (natural defence enhancer), and STODI® (to prevent and control loose droppings), for their possible mutagenicity and toxicity. Bacterial reverse mutation (BRMT) and acute oral toxicity tests were employed to assess the PFS for their possible mutagenicity and toxicity. Results indicated that the PFS were devoid of mutagenic effects in BRMT and showed higher safety profile in rodent acute oral toxicity test