Social workers use practice experience to inform scientific inquiry and use research evidence to inform practice. As with the social work practitioner, social work educators also experience ethically-based challenges in relation to EBP. NASW and CSWE clearly promote an evidence-based focus in both social work practice and education.
Another common form is a set of fingers that press on the tube in sequence. Small-volume pumps usually use a computer-controlled motor turning a screw that pushes the plunger on a syringe. The classic medical improvisation for an infusion pump is to place a blood pressure cuff around a bag of fluid. The battlefield equivalent is to place the bag under the patient. The pressure on the bag sets the infusion pressure. The pressure can actually be read-out at the cuff's indicator.
An example of a non-positive pump is a centrifugal pump. This type of pump will not pump gases and therefore requires a primer. Ejector Pumps These types of pumps do not use either mechanical pistons or plungers to increase or decrease the pressure but use a fast moving jet of liquid or gas to do the same job. This jet is called a propellant. The ejector pump uses a venture effect within the throat of the pump. At the throat an area of low pressure is created by the fast moving propellant, any movement outside this area being at a higher pressure will flow into the pump. This fluid and the propellant are discharged at the outlet.