Lateral ion implant straggle and mask proximity effect

Lateral scattering of retrograde well implants is shown to have an effect on the threshold voltage of nearby devices. The threshold voltage of both NMOSFETs and PMOSFETs increases in magnitude for conventional retrograde wells, but for triple-well isolated NMOSFETs the threshold voltage decreases for narrow devices near the edge of the well. Electrical data, SIMS, and SUPREM4 simulations are shown that elucidate the phenomenon.     

Intensity and phase measurements of nondiffracting beams generated with a magneto-optic spatial light modulator

Nondiffracting beams are of interest for optical metrology applications because the size of the beam does not change as the beam propagates. However, accuracy can be increased if the diameter of the beam is smaller. One technique for accomplishing this is to use the dark axial intensity profile associated with a higher-order nondiffracting Bessel function beam. We generate these higher-order Bessel function beams with a programmable spatial light modulator. We study the intensity patterns and the phase dependence of these nondiffracting beams. In addition, we examine interference effects caused by recording these patterns onto a binary spatial light modulator.     

Range-finding by triangulation with nondiffracting beams

Nondiffracting beams are useful for alignment applications because the size of the beam does not change as the beam propagates. In this research we report a technique that allows for distance measurements with nondiffracting beams. With our approach a diffractive optical element is designed that generates two off-axis, tilted, nondiffracting Bessel function beams. These beams intersect at a desired distance from the input plane, producing interference. We generate these Bessel function arrays with a programmable spatial light modulator allowing external control over the intersection distance.     

Contractor Process Improvement for Enhancing Construction Productivity

This paper presents a regression model that relates job site productivity to process improvement initiatives (PIIs) executed both before and during construction. Applied during early project stages, this model helps industry practitioners to predict the expected value of labor productivity based on certain inputs related to preconstruction planning and construction execution. The model demonstrates the strong relationship of project performance to a variety of PIIs including design completeness, definition of a project vision statement, testing oversight, and project manager experience and dedication. The correlational research methodology targeted 75 projects representing approximately $274.53 million in civil construction. The data collection effort considered 45 PIIs (independent variables) using quantitative and qualitative measures. The modeling technique involved the use of multiple linear regression, a method that exploits available data from multiple, independent sources to focus on specific outcomes. The model was developed directly from contractor specific information and subjected to rigorous statistical analysis. The model provides project managers as front line industry practitioners with a deliberate yet practical approach to project management and productivity enhancement. The modeling results include verification analysis and a discussion of the model’s usefulness and limitations.     

Encoding amplitude information onto phase-only filters

We report a new, to our knowledge, technique for encoding amplitude information onto a phase-only filter with a single liquid-crystal spatial light modulator. In our approach we spatially modulate the phase that is encoded onto the filter and, consequently, spatially modify the diffraction efficiency of the filter. Light that is not diffracted into the first order is sent into the zero order, effectively allowing for amplitude modulation of either the first-order or the zero-order diffracted light. This technique has several applications in both optical pattern recognition and image processing, including amplitude modulation and inverse filters. Experimental results are included for the new technique.     

Electron beam welding — a critical review

The electron beam welding process is reviewed and special reference made to the factors which are important when considering its use in relation to other welding processes. Some indication is given of the high production rates which can be achieved on component fabrication, the range of materials which can be joined and recent developments to extend the scope of the process.     

The PingER project: active Internet performance monitoring for theHENP community

The extraordinary network challenges presented by high energy nuclear and particle physics experiments has created a need for network monitoring both to understand present performance and to allocate resources to optimize performance between laboratories, and the universities and institutes collaborating on present and future experiments. The resulting Internet end-to-end performance monitoring project is called PingER. The monitoring infrastructure reflects the wide geographical spread of the collaborations, and involves a large number of research and commercial networks. The architecture of the data acquisition and methodology of the analysis have evolved over several years, and are described here in their present state. The strengths and weaknesses of the project are reviewed, and the derived metrics are discussed in terms of their diagnostic functions. The observed short-term effects and long-term trends are reviewed, and plans for future developments are described     

Assessment of polysaccharides as ice cream stabilisers

The effect of small quantities of various polysaccharides on some of the physical properties of an ice cream mix and ice cream has been investigated. The behaviour of traditional compounds was compared with the behaviour of a selection of tree exudate gums. The most effective of this group of tree exudate gums was Khaya grandifoliola gum. Although an ice cream mix containing this gum has only a low viscosity Khaya gum produced a wide range of desirable effects.