A service gateway for networked sensor systems

An emerging area in ubiquitous computing is networked sensor systems. The typical approach is to connect sensor-actuator devices using classic network infrastructures at a low level. These networks can serve as infrastructures to dynamically integrate, sensors and actuators into complex interactive systems while providing convenient services and interfaces to users. A prominent scenario for ubiquitous computing and ad hoc networking is an in-house environment using smart sensor system. Shaman, an extendable Java-based service gateway for networked sensor systems, integrates small network-attached sensor-actuator modules (SAMs) into heterogeneous, high-level networking communities. The system unburdens its connected SAMs by transferring functionality from the SAMs to the gateway.     

Stress control for overlay registration in a‐Si:H TFTs on flexible organic‐polymer‐foil substrates

Abstract— Mechanical stress in hydrogenated amorphous‐silicon (a‐Si:H) thin‐film transistors (TFTs) is becoming an important design parameter, especially when the TFTs are made on compliant substrates. Excessive stress always has been avoided to prevent film fracture and peeling. Now, attention is turning to the effects of stress on the TFT backplane dimensions and hence on the overlay alignment. The goal is to keep the size of the circuit‐on‐substrate composite structure the same at successive critical photolithographic steps. This is done most easily by keeping the structure flat. We show that a compensating stress can be dialed into the silicon nitride SiN_x) gate dielectric to also keep the substrate size constant. Varying the stress in the SiN_x gate dielectric did not significantly change the as‐fabricated TFT characteristics.     

Thermal effects and scaling in organic light-emitting flat-paneldisplays

The temperature rise in flat-panel displays without forced air cooling has been both modeled and experimentally measured as a function of the display size. Both radiation and convection are important processes for the transfer of heat to the ambient. Because of much poorer convection and the lack of lateral heat transport at large dimensions, for a fixed power density large displays are expected to be substantially hotter than small displays. This could adversely impact the reliability of large displays based on organic light-emitting diode (OLED) technology     

LDL-unbound apolipoprotein(a) and carotid atherosclerosis in hemodialysis patients

High lipoprotein(a) [Lp(a)] plasma concentrations, which are genetically determined by apo(a) size polymorphism, are directly associated with an increased risk for atherosclerosis. Patients with end-stage renal disease (ESRD), who show an enormous prevalence of cardiovascular disease, have elevated plasma concentrations of Lp(a). In recent studies we were able to show that apo(a) size polymorphism is a better predictor for carotid atherosclerosis and coronary artery disease in hemodialysis patients than concentrations of Lp(a) and other lipoproteins. Less than 5% of apo(a) in plasma exists in a low-density lipoprotein (LDL)-unbound form. This "free" apo(a) consists mainly of disintegrated apo(a) molecules of different molecular weight, ranging from about 125 to 360 kDa. LDL-unbound apo(a) molecules are elevated in patients with ESRD. The aim of this study was therefore to investigate whether the LDL-unbound form of apo(a) contributes to the prediction of carotid atherosclerosis in a group of 153 hemodialysis patients. The absolute amount of LDL-unbound apo(a) showed a trend to increasing values with the degree of carotid atherosclerosis, but the correlation of Lp(a) plasma concentrations with atherosclerosis was more pronounced. In multivariate analysis the two variables were related to neither the presence nor the degree of atherosclerosis. Instead, the apo(a) phenotype took the place of Lp(a) and LDL-unbound apo(a). After adjustment for other variables, the odds ratio for carotid atherosclerosis in patients with a low molecular weight apo(a) phenotype was about 5 (p<0.01). This indicates a strong association between the apo(a) phenotype and the prevalence of carotid atherosclerosis. Finally, multivariate regression analysis revealed age, angina pectoris and the apo(a) phenotype as the only significant predictors of the degree of atherosclerosis in these patients. In summary, it seems that LDL-unbound apo(a) levels do not contribute to the prediction of carotid atherosclerosis in hemodialysis patients. However, this does not mean that "free", mainly disintegrated, apo(a) has no atherogenic potential.     

Das Hysteresemeßwerk

Inhaltsübersicht A. Stand der Technik und Aufgabestellung.—B. Theorie des Hysteresedrehmomentes unter besonderer Berücksichtigung der bei Meßwerken vorliegenden Verhältnisse.—C. Aufnahme magnetischer Kennwerte von Hysteresewerkstoffen.—D. Die günstigste Form und Größe der Hystereseschleife.—E. Kennzeichnende Eigenschaften des Meßwerkes.—F. Praktisch ausgeführte Meßwerke.—G. Literaturverzeichnis.—H. Zusammenfassung.Mitteilung der Entwicklungsabteilung der Brown, Boveri & Cie. A. G., Stótz-Kontakt GmbH. Werk EberbachMit 26 Textabbildungen.Auszug aus einer gleichnamigen Dissertation des Verfassers (Technische Hochschule Karlsruhe, 1948).     

Mechanical characterization of polypropylene–wood flour composites

The mechanical performance of different wood flour/polypropylene (PP) composites with interface modifications was compared. Wood flour was incorporated into the matrix after esterification with maleic anhydride (MAN) or without any modification but with the addition of a compatibilizing agent [maleic anhydride–polypropylene copolymer (PPMAN)] to modify the polymer–filler interaction. Composites were prepared by injection molding with different concentrations of wood flour. Mechanical properties (except Young's modulus) were not improved either by the wood flour chemical modification or by the use of PPMAN. However, both compatibilization methods were successful in improving the dispersion of the wood flour in the PP matrix. Creep behavior of composite samples was improved by the addition of PPMAN, whereas the composites prepared from MAN‐treated wood flour showed larger deformations than composites made with untreated particles. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1420–1428, 2003     

Pyloric gland adenoma of the main pancreatic duct

A case of a pyloric gland type adenoma of the main pancreatic duct in a 69-year-old woman is reported. The tumor led to occlusion and cystic dilatation of the main duct in the pancreatic tail. The surgical resection specimen disclosed a polypoid, bilobed mass attached to the wall of the main pancreatic duct by a thin fibrous stalk. Light-microscopic examination revealed a well-demarcated nodule composed of closely packed tubular glands lined by columnar, mucin-secreting cells with abundant clear cytoplasm and basally oriented nuclei. Focal, mild cytologic atypia was seen. Pyloric metaplasia and focal papillary hyperplasia was present in the adjacent ductal epithelium. Periodic acid-Schiff reactions, with and without diastase predigestion, showed reactivity in the tubular glands, whereas alcian blue (pH 2.5) was negative. Immunohistochemical stains for chromogranin, serotonin, somatostatin, and gastrin failed to detect the respective antigens. Genetic analysis using polymerase chain reaction with mutant enrichment and allele specific oligonucleotide hybridization detected a single mutation at codon 12 of K-ras, which changed the wild-type glycine to arginine. This mutation is commonly found in invasive pancreatic ductal carcinomas. Although tumors with microscopic and immunohistochemical features consistent with pyloric gland adenoma have been described in the gallbladder, to our knowledge, this is the first reported case within the pancreatic ductal system. The finding of a K-ras, codon 12 mutation and the presence of focal dysplasia may denote neoplastic potential in association with this lesion.     

Thin-film transistors in polycrystalline silicon by blanket andlocal source/drain hydrogen plasma-seeded crystallization

Thin film n-channel transistors have been fabricated in polycrystalline silicon films crystallized using hydrogen plasma seeding, by using several processing techniques with 600 to 625°C or 1000°C as the maximum process temperature. The TFTs from hydrogen plasma-treated films with a maximum process temperature of 600°C, have a linear field-effect mobility of ~35 cm²/Vs and an ON/OFF current ratio of ~10⁶, and TFTs with a maximum process temperature of 1000°C, have a linear field-effect mobility of ~100 cm²/Vs and an ON/OFF current ratio of ~10⁷. A hydrogen plasma has also then been applied selectively a in the source and drain regions to seed large crystal grains in the channel. Transistors made with this method with maximum temperature of 600°C showed a nearly twofold improvement in mobility (72 versus 37 cm² /Vs) over the unseeded devices at short channel lengths. The dominant factor in determining the field-effect mobility in all cases was the grain size of the polycrystalline silicon, and not the gate oxide growth/deposition conditions. Significant increases in mobility are observed when the grain size is in order of the channel length. However the gate oxide plays an important role in determining the subthreshold slope and the leakage current     

Formation of core-shell and hollow nanospheres through the nanoscale melt-solidification effect in the Sm-Fe(Ta)-N system

Sm-Fe-Ta-N-O nanospheres were synthesized by pulsed-laser deposition from a Sm(13.8)Fe(82.2)Ta(4.0) target in a nitrogen atmosphere. Three structurally and compositionally distinct types were identified: amorphous, core-shell and hollow nanospheres. Amorphous spheres were compositionally homogeneous and completely oxidized. The core-shell spheres were composed of an iron-rich crystalline core with up to 10?at.% interstitially incorporated nitrogen, surrounded by an amorphous and oxidized shell. The hollow spheres were characterized by voids filled with N(2) gas. It was found that the formation of either amorphous or complex nanospheres is defined by an initial Fe/Sm ratio within the molten droplet. The formation of hollow spheres is believed to be related to the general affinity of liquid metals for gas intake. During rapid solidification the dissolved gas in the melt is trapped within the surrounding solid rim, preventing the outwards diffusion of gas. As long as the amount of gas atoms in the melt is kept below its solubility limits it can be completely interstitially incorporated into the solid, thus forming crystalline Fe(N)-rich cores. If the melt contains more than an equilibrium amount of nitrogen it is possible that the gas recombines to form N(2) molecules, which are condensed inside the spheres.