Round Valve in an Oval Hole

Round Valve in an Oval Hole

Progressive narrowing of the aortic valve orifice eventually leads to limitations in cardiac output and myocardial blood flow, particularly during exercise or other physiological stress. The pressure gradient across the stenotic aortic valve is a useful and reproducible measure of the severity of the stenosis in most patients. The mainstay of therapy for aortic stenosis is relief of the fixed o...

Square peg in a round hole.

Square Peg Reforms in round Hole Governments

Government often dominates developing countries. Sometimes government is the only game in town. Countries suffer when rules of this game are deficient and governments are ineffective or predatory. Because this frequently seems to be the case, public sector institutional reforms have emerged as central to development. These reforms are an essential element of interventions by players like the Wo...

A square peg in a round hole.

My fear is that the hopes that I have for my practice, and the beliefs I have come to hold regarding how I would like to teach will be worn down by the myriad realities and pressures I am likely to experience as a beginning teacher. In many ways I suspect that the teaching tools with which I have been equipped by my pre-service training, based largely on constructivist principles, may ill-prepa...

Dynamic Stress of Refrigeration Compressor Reed Valve with Oval Shape

The purpose of this study is both theoretically and experimentally to clarify the dynamic stress of a discharge reed valve with oval shape, and to get fundamental knowledge for the design of this type valve and its related parts. The strain measurements were performed on the strain gauge bonded on the surface of the oval shaped reed valve. The stress and deformation of the valve were also calcu...