Statistical simulation of IC technology: A bipolar process example

Statistical simulation using design of experiments has been employed for integrated circuit technology development. A software program called STADIUM was developed to implement this statistical methodology. The software has been designed to be user friendly and to guide the engineer who is not a statistics expert through the process of deriving a valid statistical answer. Inputs to the STADIUM system include integrated circuit fabrication variations and when coupled with semiconductor process and device simulators can estimate the expected variations of device parameters such as transistor gain and threshold voltage. This paper presents the detailed procedure and results of a statistical simulation of a bipolar transistor technology.     

European proficiency testing of national reference laboratories for the confirmation of sulfonamide residues in muscle and milk

Two interlaboratory studies were organized in 2002-2003 in order to check the proficiency of laboratories in confirming the presence of sulfonamide residues in muscle and milk. These studies involved 25 EU National Reference Laboratories (NRLs) from 21 different European countries in charge of statutory monitoring of antimicrobial residues in food of animal origin at a national level. The study was conducted according to international and national guidelines by the Community Reference Laboratory (CRL) in charge of antimicrobial substances. Four different test matrices of sheep muscle and four different test matrices of bovine milk containing different sulfonamide substances were prepared and sent to the participants. Each participant was asked to use his own routine confirmatory method and to analyse each sample in triplicate within a period of about six weeks during which the stability of the materials was checked by the organizer. The sulfonamide content of each material was determined by calculating the robust means of all the results and the deviation of the results from the assigned values was assessed by calculating Z-scores. Overall, results were satisfactory, particularly considering that it was the first proficiency test dealing with sulfonamides organised by the Community Reference Laboratory.     

Dynamic multi-phase partitioning of decamethylcyclopentasiloxane (D5) in river water

The behaviour of decamethylcyclopentasiloxane (D5) in river water was evaluated by measuring concentration changes in open beakers. Effective values for the partition coefficient between organic carbon and water (K_OC) were derived by least-squares optimisation of a dynamic model which accounted for partitioning between the sorbed and dissolved phases of D5, and for losses via volatilisation and hydrolysis. Partial mass transfer coefficients for volatilisation were derived from model fits to controls containing deionised water. Effective values of log (K_OC) were between 5.8 and 6.33 (mean 6.16). These figures are higher than some other experimentally-derived values but much lower than those estimated from the octanol: water partition coefficient using single-parameter linear free energy relationships (LFERs). A poly-parameter LFER gave a predicted log (K_OC) of 5.5. Differences in partitioning are believed to be due to the nature of the organic matter present. The new value for effective K_OC was employed in a simple model of D5 behaviour in rivers to ascertain the extent to which a higher affinity for organic carbon would depress volatility. The results suggest that despite the revised K_OC value, volatilisation of D5 remains a significant removal mechanism in surface waters.     

X-ray absorption near edge structure (XANES) andconversion electron Mössbauer spectroscopy (CEMS) study of perfluoropolyalkylether based additives

This study provides critical insight regarding the interactions of perfluoropolyalkylether (PFPAE) additives with Fe-based alloys. PFPAEs are primary candidates for the development of high temperature liquid lubricants for the next generation of turbine engines because of their chemical and thermal stability. However, a PFPAE must be tailored for its particular application by the addition of soluble additives. Currently, two additives that show promise for improved performance are a substituted triphenylphosphine and a bis-substituted benzothiazole. To date, little work has been reported on the mechanism by which these additives actually improve overall performance. In order to gain some understanding of how these additives work, a series of oxidation-corrosion tests were performed using these additives in Demnum with the resulting coupons examined by X-ray absorption near edge structure (XANES) and conversion electron Mössbauerspectroscopy (CEMS).     

Enhancement of JET’s mirror-link near-ultraviolet to near-infrared divertor spectroscopy system

Since 1994, JET has had a mirror-link spectroscopy system with a poloidal view of 150 mm of the outer divertor split into three ranges: near-ultraviolet (near-UV) (～ 300–450?nm), visible (450–750 nm), and near-infrared (near-IR) (750–1200 nm). The system consists of three Czerny–Turner/charge coupled device (CCD) pairs: 1 m focal length for the near-UV, 0.75 m focal length for the visible, and 0.5 m focal length for the near-IR. All were aligned along the same optical path to the divertor. As part of the JET ITER-like wall enhancements, the diagnostic system will be upgraded in five areas: (1) frame rate, (2) quantum efficiency (QE), (3) radial coverage, (4) optical throughput, and (5) for the near-UV, spectral resolution and survey capability. New CCDs for the near-UV and visible will have increased QE and allow three times frame rate. The near-UV will benefit from a 0.75 m imaging spectrometer with three gratings. The optics have been redesigned to allow ～ 360?mm view and greater than two times throughput. This paper will look at the design and implementation as well as the new diagnostic capabilities of the system.     

Liquid to Semisolid Rheological Transitions of Normal and High-oleic Peanut Oils upon Cooling to Refrigeration Temperatures

Rheological transitions of peanut oils cooled from 20 to 3 °C at 0.5 °C/min were monitored via small strain oscillatory measurements at 0.1 Hz and 1 Pa. Oils were from nine different cultivars of peanut, and three oils were classified as high-oleic (approximately 80% oleic acid). High-oleic oils maintained an overall liquid-like character at 3 °C for 2 h. In contrast, several normal (non high-oleic) peanut oils displayed a predominantly elastic (solid-like) response after 2 h at 3 °C. Increases in viscoelasticity were associated with lipid crystallization events as confirmed by DSC. The higher (p < 0.001) liquid viscosities and increased (p < 0.001) contents of oleic acid, which has a more non-linear structure as compared to other fatty acids typical in these oils, were hypothesized to hinder crystallization in high-oleic oils. Changes in viscoelasticity at 3 °C were greatest for three normal oils that had the significantly (p < 0.001) highest content of C20:0 and/or C22:0 fatty acids, and these long, saturated hydrocarbon chains are hypothesized to promote crystallization. No peanut oil maintained clarity after 5.5 h at 0 °C (modified cold test used to screen salad oils); however, these data as a whole suggest strategies for breeding and/or processing peanut oils for enhanced resistance to crystallization. The use of trade names in this publication does not imply endorsement by the United States Department of Agriculture: Agricultural Research Service.