The vessel may be oriented such that the external gradient acts in opposition to, or in conjunction with, the influence of {HEAD ~ gravity} upon {TAIL ~ the target material} 
upon
The vessel may be oriented such that the external gradient acts in opposition to , or in conjunction with , the influence of { HEAD ~ gravity } upon { TAIL ~ the target material }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL