The effect of surface roughness on the radiative properties ofpatterned silicon wafers

The radiative properties of patterned silicon wafers have a major impact on the two critical issues in rapid thermal processing (RTP), namely wafer temperature uniformity and wafer temperature measurement. The surface topography variation of the die area caused by patterning and the roughness of the wafer backside can have a significant effect on the radiative properties, but these effects are not well characterized. We report measurements of room temperature reflectance of a memory die, logic die, and various multilayered wafer backsides. The surface roughness of the die areas and wafer backsides is characterized using atomic force microscopy (AFM). These data are subsequently used to assess the effectiveness of thin film optics in providing approximations for the radiative properties of patterned wafers for RTP applications     

Probing the early stages of polymerization of ethylene on a model chromium/silica catalyst by Fourier transform infrared spectroscopy

The nature of the interaction of monomer, and the early stages of growth of oligomers of ethylene on a rather more uniform surface of Cr/SiO₂ catalyst than hitherto studied has been investigated by differenceFTIR spectroscopy using C₂D₄ and C₂H₄ as reactants both with and without subsequent treatment of the catalyst with CO andTHF. The active catalyst was prepared by reaction of vapour phase CrO₂Cl₂ with the vicinal hydroxyls of the silica surface. Three distinct kinds of methylene groups were detected. Arguments are given for assigning the peaks at 2935 and 2860 cm^–1 to CH₂ groups directly bound to the active site and those at 2920 and 2850 to CH₂s in the growing chain well removed from the Cr. The peaks at 2160 and 2165 cm^–1 are attributed to CD₂ groups hydrogen bonded to surface hydroxyls.     

Middle cerebral artery main stem thrombosis in two siblings with familial thrombotic thrombocytopenic purpura

Idiopathic thrombotic thrombocytopenic purpura (TTP) is frequently complicated by microinfarcts in cerebral cortex and subcortical white matter. We describe two sisters who suffered massive hemispheric infarction due to thrombosis of the middle cerebral artery main stem during exacerbations of TTP. Acute TTP may be associated with intraluminal thrombosis of large-diameter arteries in addition to arterioles and capillaries.     

The use of force modulation microscopy to investigate block copolymer morphology

Force modulation microscopy (FMM) is used to characterize the external surface and internal fracture surface morphologies of three different block copolymer samples. A roll-cast poly(styrene-butadiene-styrene) triblock copolymer film, spin-coated poly(styrene-b-methyl methacrylate) thin films, and an ultrathin poly(styrene-b-hexyl isocyanate) rod-coil block copolymer film were investigated. For each sample, height and elasticity images were obtained for the same areas allowing direct comparison. The elasticity images obtained using force modulation microscopy were independent of surface roughness and found to exhibit better contrast and spatial resolution of the respective block copolymer domains than the height images. The lateral resolution of the elasticity images was sufficient to show microphase separated domains having length scales as small as about 10 nm. The poly(styrene-b-methyl methacrylate) samples demonstrate that FMM can even be successfully used to study block copolymers in which both blocks are glassy under the conditions of measurement.     

Software for dynamic reconfigurable order picking systems

This paper describes an approach, conceptual framework, and software architecture for dynamic reconfiguration of the order picking system. The research and development project was sponsored by the Material Handling Research Center (MHRC), a National Science Foundation sponsored Cooperative Industry/University Research Center. The storage configuration is assumed to be an in-the-aisle order picking system in which stockkeeping units (SKUs) can occupy variable capacity storage locations and stock-splitting is allowed among zones (clusters). The product mix may include multiple product families with different life cycles, correlated demand within families and commonality of demand across families.     

The bone marrow stromal environment is a major factor in myeloma cell resistance to dexamethasone

The expression of several markers of epithelial cell proliferation was analyzed to establish baseline data for future chemoprevention studies of oral premalignant lesions. Punch biopsies (n = 60) from three different sites of oral mucosa (bucca, lateral tongue, and the floor of the mouth) were obtained from 20 normal donors of both sexes. After formaldehyde fixation and paraffin embedding, immunohistochemistry was used to detect the proliferation markers Mib-1, cyclin D1, and centromere-associated protein CENP-F. Analysis of sections stained for the three markers showed similar patterns, i.e., a low labeling index (LI) in the basal layer and a high LI in the parabasal layer at all three intraoral sites. No proliferative activity was seen above the parabasal layer (superficial layer). All sites showed similar Mib-1 LI values for the proliferative markers. The tongue epithelium exhibited higher parabasal LIs of cyclin D1 and CENP-F than did the other two sites. No significant differences were detected between smokers and nonsmokers. The data from normal mucosa were compared with those from low (n = 30)- and high (n = 17)-grade dysplastic leukoplakias. The Mib-1 LI showed a very significant change, with a 9-fold increase in the basal layer LI in dysplastic leukoplakias. Cyclin D1 and CENP-F showed similar trends with increments of up to 7-fold in the basal layer of high-grade dysplasia. Although the proliferative activity of the parabasal layer was similar in normal and leukoplakic epithelia, the superficial layer showed a significant increment in proliferative activity mainly in high-grade leukoplakia. These studies suggest that proliferation markers in the basal and superficial cells of premalignant lesions may serve as surrogate end point biomarkers for chemoprevention trials.     

Non-redundant data clustering

Data clustering is a popular approach for automatically finding classes, concepts, or groups of patterns. In practice, this discovery process should avoid redundancies with existing knowledge about class structures or groupings, and reveal novel, previously unknown aspects of the data. In order to deal with this problem, we present an extension of the information bottleneck framework, called coordinated conditional information bottleneck, which takes negative relevance information into account by maximizing a conditional mutual information score subject to constraints. Algorithmically, one can apply an alternating optimization scheme that can be used in conjunction with different types of numeric and non-numeric attributes. We discuss extensions of the technique to the tasks of semi-supervised classification and enumeration of successive non-redundant clusterings. We present experimental results for applications in text mining and computer vision.     

Erfolgsfaktoren bei der Einführung von Wissensmanagementsystemen in die Praxis

Neben der Gestaltung technischer Systeme zur Unterstützung des Wissensmanagements ist die Ausgestaltung organisatorischer Ma?nahmen gleichbedeutend wichtig.