Control of airborne nickel welding fumes by means of a vertical laminar air flow system

The purpose of this study was to evaluate the effeciveness of a clean room facility with laminar air flow in the control of nickel fumes released from metal inert gas (MIG) and shielded metal arc (SMA) welding operations performed on mild steel using nickel filler materials. From data observed in these experiments, it appears that the laminar flow clean room approach to controlling welding fumes can be successful in certain small table top welding operations. However, almost any interferences that obstruct the downward airflow can result in eddy currents and subsequent build-up of fumes by entrapment. Airflow patterns differ significantly when comparing table top operations to welding on large cylindrical and/or doughnut shaped items. (JGB

Replanting Decision Based on Soybean Stand Establishment and Cultivar Maturity

When soybean crops experience poor stands due to poor emergence, farmers may opt to replant the crop. The increased cost of replanting must be weighted to determine if replanting is justifiable. Increased chance of frost damage due to the replanting is a possible outcome. A study of 2 soybean varieties were tested, McCall and Ozzie. In the study, a stand of less than 76,000 plants per acre would be needed to justify the added cost of replanting. A deadline of June 4th would be better than a short-term cultivar. Ozzie was viewed as being a better choice for replanting, if necessary, due to the added output