aphids in unsprayed canola (brassica napus linnaeus) fields in isfahan province (central iran) were sampled for two growing seasons, 2011-2013. sampling unit was a whole plant and 20 plants were sampled weekly. in the laboratory, heat-extracting and sub-sampling techniques were used to estimate the density of aphids. to determine the relationship between population growth rate of the aphids and...

proper estimation of droplet growth rate plays a crucial role on appropriate prediction of supersonic separators performance for separation of fine droplets from a gas stream. up to now, all available researches employ empirical or semi-empirical correlations to define the relationship between droplet growth rate (dr/dt) and other operating variables such as temperatures (t and tl), pressure (p...

chemical vapor deposition (cvd) is one of the most important methods for producing carbon nanotubes (cnts). in this research, a numerical model, based on finite volume method, is investigated. the applied method solves the conservation of mass, momentum, energy and species transport equations with aid of ideal gas law. using this model, the growth rate and thickness uniformity of produced cnts,...

abstract an experiment was conducted to study growth analysis and evaluation of change in simple non- structural carbohydrates (sucrose, glucose and fructose) during bulb formation of ghermez azarshahr , zargan, safid naishaboor and safid qom cultivars in randomized complete block design containing three replications. seeds were sown in nursery in early february and seedlings were transplanted ...

background:the present study designed to test  effects of defatted soy-fortified wheat bread on the organoleptic properties as well as influences on rat growth rate. methods: defatted soy flour (dsf) was blended with wheat flour with extraction rate of 82-84% at 3, 7, and 7% levels plus 3% sugar. bread produced with these blends compared with regular taftoon bread and was tested for chemical an...

this study was conducted to evaluate the effects of beta plus probiotic, a mixture of bacillius leicheniformic and bacillius subtilis , on the growth performance and intestinal microbial flora of caspian trout ( salmo caspius ). a basal diet was formulated and supplemented with beta plus at 0, 0.5 and 1 g kg -1 , leading to three experimental diets. each experimental diet was randomly assigned ...

the cotton bollworm, helicoverpa armigera (hübner), is one of the important polyphagous pests causing serious loss to many economically important crops in iran. the goal of this experiment was to study the age-stage, two-sex life table of h. armigera on different bean cultivars including white kidney bean (cultivars daneshkadeh, pak, and shokufa), red kidney bean (cultivars akhtar, naz, and say...

The focus of this study is the degradation of a near pearlitic microstructure under combined mechanical and thermal loadings leading to changes in mechanical properties. More specifically, it is examined how the orientation gradients inside the pearlite colonies, affect the spheroidisation. Samples were extracted from virgin near pearlitic railway wheels and prestrained, thereafter heat treated...

Shielded metal arc welding and thermal simulation experiment were carried out for constructional steel containing 0% V 0.10% V, the microstructure, precipitation feature, microhardness HV0.2, −20 °C impact value in heat affected zone (HAZ) investigated. The results showed that coarse-grained (CGHAZ), N completely dissolved matrix of to promote growth prior austenite grains, meanwhile fraction h...

Abstract This research paper mainly studied the microstructure and hardness of weld bead welding heat affected zone ultrafine grain steel after CO 2 gas-shielded welding. After normalizing quenching treatment, changes in welded joints were studied. These experimental results showed that joint was dendritic. The a mixed structure proeutectoid ferrite, side plate bainite, pearlite. overheated HAZ...