Electrically programmable fuse (eFUSE) using electromigration insilicides

For the first time we describe a positive application of electromigration, as an electrically programmable fuse device (eFUSE). Upon programming, eFUSE's show a large increase in resistance that enable easy sensing. The transient device characteristics show that the eFUSE stays in a low resistance state during programming due to the local heating of the fuse link. The programming is enhanced by a device design that uses a large cathode which increases the temperature gradient and minimizes the effect of microstructural variations     

Using constraint sets to achieve delay bounds in CIOQ switches

We previously proposed constraint sets as a simple technique to analyze routers with a single stage of buffering. We extend the technique to analyze combined input and output (CIOQ) routers with two stages of buffering.     

Feedback system design: The single-variate case — Part I

A recently developed algebraic approach to the feedback system design problem is reviewed via the derivation of the theory in the single-variate case. This allows the simple algebraic nature of the theory to be brought to the fore while simultaneously minimizing the complexities of the presentation. Rather than simply giving a single solution to the prescribed design problem we endeavor to give a complete parameterization of the set of compensators which meet specifications. Although this might at first seem to complicate our theory it, in fact, opens the way for a sequential approach to the design problem in which one parameterizes the subset of those compensators which meet the second specification...etc. Specific problems investigated include feedback system stabilization, the tracking and disturbance rejection problem, robust design, transfer function design, pole placement, simultaneous stabilization, and stable stabilization.This research was supported by the Joint Services Electronics Program at Texas Tech University under ONR Contract 76-C-1136.     

Significance of the failure criterion on transmission line pulse testing

When characterizing semiconductor components to determine their ESD robustness using a transmission line pulse (TLP) test system, there is no universally accepted standard procedure for performing the test available at present. In this paper, we address this issue whereby we study the impact of the following TLP characterization related variables: failure criterion, influence of stress step size and cumulative stress effects. We show that the failure criterion, ‘any increase in leakage', yields the most reproducible and reliable results in the devices tested.     

Solitons in a linear lattice with defects

Solitons are generated in an anharmonic linear lattice in which neighbouring atoms interact through a Morse potential by giving either a strong initial impulse or a large displacement to an end atom. Studies on the variation of the characteristic properties of the soliton with the strength of the initial pulse show that the velocity and the amplitude of the soliton increase with the strength of the initial impulse, but below a certain critical value for the initial impulse, only an oscillatory tail is generated. It is shown that when a defect is present in the lattice, a localised mode appears at the site of the defect and additional solitons travelling forward or even backwards, are generated. When two solitons collide at a defect region, they reemerge but leave a localised mode at the site of the defect. If an initial velocity is imparted to a particular particle, synchronously with the crossing of the particle by the soliton, a localised mode emerges at the site of the particle and additional solitons are also generated. When a soliton moves from a denser to a rarer medium, a strong localised pulse is created near the region of the density discontinuity and additional solitons appear; and further a weak oscillatory tail is left behind in the denser medium. On the other hand, if a soliton moves from a rarer to a denser medium, it is reflected back and a small localised mode is generated at the site of the density discontinuity. The variation of amplitude of the soliton with the velocity of propagation is also studied.     

Unbonded contact between a circular plate and an elastic half-space

The paper concerns the unbonded contact between a thin circular plate of finite radius, governed by Kirchhof or Reissner theory, pressed by means of rotationally symmetric distributed load and its own weight against the surface of an elastic half-space. The contact is assumed frictionless and unbonded. A Hankel transform solution is used for the half-space and the plate deflection is found by inverting the plate equation. The coefficients in a power expansion are obtained by equating plate and half-space deflections at a number of points in the contact region. The variation of contact radius with plate radius, the radius of the uniformly applied load, and the relative stiffness of plate and foundation, is displayed in a series of figures.     

Detection of intact influenza viruses using biotinylated biantennary S-sialosides

We report the modular synthesis of robust, biotinylated biantennary sialylglycoconjugates and their ability to differentiate between two type A influenza strains. This is the first demonstration of glycoconjugate-based discriminatory capture and detection of two strains of intact influenza virus, in the presence of the innate enzymatic activity of viral neuraminidases. We also demonstrate a "carboassay" using glycoconjugates as capture and reporter elements, which therefore, does not require antibodies. The capture of intact influenza viruses is of potential benefit for clinical diagnostics.     

Cyclization cascade of allenyl azides: a dual mechanism

A density functional theory based computational approach to describing the mechanistic course of the allene azide cycloaddition cascade sequence has been developed. The results of these calculations permit characterization of key reactive intermediates (diradicals and/or indolidenes) and explain the different behaviors observed in the experimental studies between conjugated and nonconjugated species. Furthermore, computational analysis of certain intermediates offer insight into issues of regioselectivity and stereoselectivity in cases where different reaction channels are in competition, suggesting suitable substitutions to achieve a single regioisomer in the indole synthesis via azide-allene cyclization.     

Eu3(AsS4)2 and AxEu(3-y)As(5-z)S10 (A = Li, Na): compounds with simple and complex thioarsenate building blocks

Eu(3)(AsS(4))(2) and A(x)Eu(3-y)As(5-z)S(10) (A = Li, Na) are the members of a new thioarsenate family. They feature As(5+) and As(3+) centers, respectively. The rhombohedral Eu(3)(AsS(4))(2) features a new structure type consisting of eight-coordinate Eu(2+) centers and AsS(4)(3-) anions, whereas the monoclinic A(x)Eu(3-y)As(5-z)S(10) (Li(0.73)Eu(3)As(4.43)S(10) and Na(0.66)Eu(2.86)As(4.54)S(10)) belong to the rathite sulfosalt family and are comprised of apparent [As(10)S(20)](10-) segments linked with Eu(2+) ions to give a three-dimensional network. They appear to be alkali-metal-stabilized derivatives of the putative parent phase "Eu(3)As(5)S(10)".