Preliminary reports of part of this work have appeared in abstract form in Clin. Res. 26: 503A, 1978, and in Blood. 54(Suppl. 1): 241a, 1979. Dr. Gerrard and Dr. Plow are established Investigators of the American Heart Association. Reprint requests should be addressed to Dr. Gerrard, Manitoba Institute of Cell Biology, Manitoba R3E OV9, Canada. Received for publication 15 November 1979 and in r...

The paper studies the direction turnover layers along slope and placement of working bodies on a plow for plowing fields. diagrams layout are given. It is proved that intermittent grooves ridges, according to agro technical requirements, it necessary rotate downhill. was found when installing cut-out spherical disk behind front cases, groove formed above under it. subsequent layer wrapped in an...

The pick is the working part of coal plow, cutting performance very important for efficient production mine. In order to analyze dynamic characteristics plow during process, a test platform was built. force and vibration head were obtained through test, relationship between speed depth analyzed. study influence different alloy shapes on pick, two kinds designed: with chip bit conical bit. finit...

ated with soil type, vadose zone flow and transport processes are also affected by such external factors as tillage Vadose zone flow and transport processes are known to be strongly practices. For example, Petersen et al. (1999, 2001) affected by both soil structure and soil texture. We conducted a field experiment to explore the impact of heterogeneity in soil structure showed that surface til...

performance optimization of chisel tine was proposed by using a chisel plow with adjustable rake angle. effective treatments consisted of soil moisture at 0.5, 0.7 and 0.9 of plastic limit (pl), three rake angle of 30, 40 and 50 degree and speeds of to 3, 5 and 7 km h-1. the measured parameters included draft, soil disturbance area, soil upheaving area, clod mean weight diameter (mwd), specific...

In cold weather cities, snowstorms can have a significant disruptive effect on both mobility and safety, and consequently the faster that streets can be cleared the better. Yet in most cities, plans for snowplowing are developed using simple allocation schemes that while easy to implement can also be quite inefficient. In this paper we consider the problem of optimizing the routes of a fleet of...