tillage and press wheel weight play an important role in seedling emergence, crop establishment and growth. an optimal combination of tillage implements and suitable press wheel weights should increase grain yield. this study investigated the effect of tillage systems and press wheel weights on dry land wheat (triticum aestivum l.) seedling emergence and grain yields in izeh, khuzestan province...

poor stand establishment of canola (brassica napus l.) under flatland mechanized planting and crust-forming soil is a major problem for farmers in central iran. previous research there showed that irrigated cotton emergence on crust-forming soils under flatland planting can be significantly improved using a double-disk planter with zero-pressure press wheel tires and no crust-breaking. in that ...

Press-wheels are wheels designed to compact the soil above seeds in “seed cover” region. Soil compaction, produced by press-wheels of seeders, affects seedling emergence and early plant growth. The Discrete Element Method (DEM) was used model amount compaction from a press-wheel with varying down forces. predict sinkage rolling resistance press-wheel. results were validated data bin tests sandy...

Accurate disturbance models are necessary to predict the e!ects of vibrations on the performance of precision space-based telescopes, such as the Space Interferometry Mission (SIM). There are many possible disturbance sources on such spacecraft, but mechanical jitter from the reaction wheel assembly (RWA) is anticipated to be the largest. A method has been developed and implemented in the form ...

A simple method for studying operant wheel running in rats. The present report describes an operant running device for rats. The apparatus makes use of an activity wheel driven by a small electric motor. The motor is started by a bar press; once activated, the wheel turns for 3-30 sec. depending on the setting of a timing device. The system is well suited to long term studies of activity patter...

Rats were required to press a bar to activate a motor-driven wheel that forced them to run and subsequently to drink to turn off the wheel. Barpressing and lickilng increased, showing the onset and offset of running to be positively and negatively reinforcing, respectively. The experimental control of the offset of running, in contrast to the traditional control for onset only, served to demons...

Bertrand, Diane Gonzales. My Pal, Victor/Mi Amigo, Victor. Raven Tree Press, 2004. Dominic relates all the wonderful things he does with his best friend Victor; telling scary stories at sleepovers, swimming at the pool, riding rollercoasters. The surprise ending is learning that Victor uses a wheel chair. Bilingual text in English and Spanish. For kindergarten to grade 3. Schneider Family Book ...

In the decade 2008–18, between eruption of phone hacking scandal and cancellation part two Leveson Inquiry, editorial position The Guardian on press regulation went from indifference to demanding wholesale reform, then back even active opposition change. Inevitably, this entailed reversals contradictions, yet these were not acknowledged newspaper’s readers, who are left with a misleading impres...