tillage systems influence soil physical, chemical and biological characteristics which in turn may alter, root characteristics, growth, and development. a three year study was conducted to investigate the effects of seven tillage systems on some soil (fine-loamy mixed, typic haplocambids) physical characteristics and wheat (triticum aestivum l.) root morphology. tillage treatments included ...

a new mechanical cultivator was proposed for mechanical weeding in part one. the precise point method was used to geometric design of this new cultivator. the aim of this research is selecting the suitable mechanism of the studied mechanisms in part one. the velocity and acceleration of links (kinematic) is the base of dynamic analysis of the systems. the variation of velocity, acceleration and...

introduction: the aim of this in vitro study was to compare the effect of hand and rotary instruments on fracture strength of tooth roots. materials & methods: thirty two teeth were randomly divided into two experimental groups of 15 each and one negative control group with two samples. in group 1, step-back technique with conventional stainless steel k-files was used, and in group 2, instrumen...

in order to compare of ecological management of weed control on economical income, yield and yield components of cotton (gossypium hirsutum l.), a randomized complete block design with 12 treatments and four replications was conducted in mahvelat of khorasan razavi province, iran. treatments consisted of weeding, harrowing, burning, two times weeding, weeding + harrowing, weeding + burning, har...

OBJECTIVES The purpose of this study was to compare in-vitro the amount of debris extruded apically from extracted teeth, using K3, Protaper rotary instruments and manual step-back technique. METHODS Forty five human single-rooted mandibular premolar teeth were randomly divided into 3 groups. The teeth in 3 groups were instrumented until reaching the working length with K3, Protaper rotary in...

The aim of this study was to evaluate the performance of undergraduates in their first contact with manual and rotary root canal instrumentation. Forty-two students who had never worked on a root canal before instrumented 42 extracted lower-incisors. Participants were assigned to one of two groups: Rotary instrumentation or manual instrumentation. Pre- and post-operative computed tomography sca...

PURPOSE To compare the percentage of collagen exposed in dentin root thirds after two irrigation protocols with manual or rotary instrumentation using two methacrylate resin-based sealers. MATERIALS AND METHODS Forty-eight single-root human teeth were prepared with manual (n = 24) or nickeltitanium ProFile rotary (n = 24) instrumentation, using 5% NaOCl between instruments and 5 ml 17% EDTA a...

in order to compare different weed management methods in sugar beet, an experiment was conducted at the agricultural research station, ferdowsi university of mashhad, iran, during 2006-2007 and 2007-2008. the experiment designed as a complete randomized block with three replications. the treatments including: metamitron + fenmedifam, metamitron + fenmedifam + rotation, metamitron + cultivation,...