the aim of this study was to show the effect of four feeding regimes on thyroid hormones concentrations, growth performance and food coefficient in rainbow trout applied through 4 treatments and 3 replications in winter 2006. in this research, samples of rainbow trout with an initial mean weight (so) 47.19±0.42 used in each rearing unite. fish were fed twice a day ad libitum as follows: treatme...

The current study assesses the root causes of hydrogen blisters on low strength carbon steel equipment. For this purpose, some experiments including hardness test, non-destructive test (NDT), metallography, and fractograpghy are conducted. The microstructure of two blisters is assessed by means of optical microscopy and scanning electron microscopy (SEM). The microstructural studies show that t...

The influence of aluminum, within the range of 0.08 - 6.16 wt.%, on the microstructure and hardness of as-cast ductile cast iron has been studied. A number of irons of different composition have been made by green sand casting and gravity die casting of appropriate design to provide the experimental materials. It has been found that Al addition and higher cooling rates in permanent mould castin...

Background Childhood growth factors play an essential role in the process of child development. Providing an accurate measurement for determining the growth rate predictors longitudinally has an advantage over a growth chart that only measures cumulative growth. This study aimed to determine the trends in growth rate and its effective factors a...

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...

The influence of carbon concentration variations on pearlite formation (20 h at 600 °C) in a case-carburized steel is investigated. resultant microstructure shows three distinct regions: carburized case, transition region, and the original core. microstructural from case to core regions observed be relatively sharp. investigated region (0.9 wt.% C) contains two types pearlite: ferrite + cementi...