Printed circuit board with bellows rivet connection Patent

Electrical connection for printed circuits on common board, using bellows principle in rive

Coupled Mode Theory of Electron‐Beam Parametric Amplification

A theory of parametric amplification in a filamentary electron beam by transverse fields is developed in coupled mode form. Space charge effects are neglected. In addition to beam modes at the signal frequency, beam modes at frequencies ωn=ω+ω_p, n=0, ±1, ±2…, where ω_p is the pump frequency, are coupled together. A discussion of the general form of the equations is given and reveals the circumstances under which exponential gain or periodic energy transfer between various modes can occur. When applied to quadrupole electric pump fields, a description of the quadrupole amplifiers of Adler, Wade, and Gordon is obtained. This theory is then used to evaluate the noise contribution from synchronous beam modes and higher cyclotron idler modes. Coupling by axially symmetric electric fields and by axially symmetric magnetic fields is discussed, and other amplification schemes suggested. The theory of coupling by axially symmetric fields can also be used to study lens effects on noise in the gun region

The role of intellectual property rights in economic growth

Economic development ; Intellectual property

GATT and the new protectionism

The Uruguay Round of the General Agreement on Tariffs and Trade (GATT) is the first agreement of its kind that reduces or eliminates tariffs on many goods and addresses issues related to intellectual property rights, trade in services and agricultural subsidies. With good reason, it has generated much optimism about the future of free world trade. ; But does GATT's trade liberalization today mean that trade will remain liberalized tomorrow? Increasingly, governments are counteracting the perceived unfair trade practices of other nations with their own trade barriers. While concerns about fairness are legitimate, raising trade barriers to counteract actual or perceived unfair trade practices of others is another form of protectionism that restricts world trade. This new protectionism has most often taken the form of antidumping and countervailing duties. ; Because the use of antidumping and countervailing duties has grown dramatically in recent years across many countries, David Gould and William Gruben analyze whether the recent changes to the GATT accord will discourage the most protectionist aspects of these widely used trade barriers. Gould and Gruben find that while the new GATT agreement does not eliminate the ability of such countries to misuse antidumping and countervailing duties, the accord delineates the rules of such duties much more clearly and provides mechanisms that will likely limit their abuse.International trade