1,307 research outputs found

    Workshop on an Assessment of Gas-Side Fouling in Fossil Fuel Exhaust Environments

    Get PDF
    The state of the art of gas side fouling in fossil fuel exhaust environments was assessed. Heat recovery applications were emphasized. The deleterious effects of gas side fouling including increased energy consumption, increased material losses, and loss of production were identified

    A survey of gas-side fouling in industrial heat-transfer equipment

    Get PDF
    Gas-side fouling and corrosion problems occur in all of the energy intensive industries including the chemical, petroleum, primary metals, pulp and paper, glass, cement, foodstuffs, and textile industries. Topics of major interest include: (1) heat exchanger design procedures for gas-side fouling service; (2) gas-side fouling factors which are presently available; (3) startup and shutdown procedures used to minimize the effects of gas-side fouling; (4) gas-side fouling prevention, mitigation, and accommodation techniques; (5) economic impact of gas-side fouling on capital costs, maintenance costs, loss of production, and energy losses; and (6) miscellaneous considerations related to gas-side fouling. The present state-of-the-art for industrial gas-side fouling is summarized by a list of recommendations for further work in this area

    Privatisierung der Autobahnen: Soll der Bund sein Tafelsilber verkaufen?

    Full text link
    Gegenwärtig wird der Verkauf des deutschen Autobahnnetzes diskutiert. Mit den Privatisierungserlösen könnte ein erheblicher Teil der Verschuldung des Bundes abgebaut werden. Ist die traditionelle staatliche Bereitstellung noch gerechtfertigt? Wie weit sollte eine Autobahnprivatisierung gehen

    Specific Investments and Ownership Structures in Railways – An Experimental Analysis

    Get PDF
    We analyze the impact of different organizational structures on incentives to invest in railways: vertical integration, vertical separation, and a hybrid form. Economic theory predicts that vertical integration fosters socially optimal investment, whereas, due to potential hold-up problems, both vertical separation and hybrid forms cause severe underinvestment. We test these theoretical predictions in a laboratory experiment and find evidence that, in a vertically integrated environment, the level of investment in rolling stock and in rail infrastructure is roughly socially optimal. The complete absence of a discrepancy in our experimental results between vertical separation and the hybrid organisational structure, contradicting the predictions of model-theory, is surprising and can be attributed to the relatively high investments in the separated model. This contradiction might also be explained by the existence of social preferences.game theory, vertical separation, railways, experimental economics

    Privatisierung der Autobahnen: Soll der Bund sein Tafelsilber verkaufen?

    Get PDF
    Gegenwärtig wird der Verkauf des deutschen Autobahnnetzes diskutiert. Mit den Privatisierungserlösen könnte ein erheblicher Teil der Verschuldung des Bundes abgebaut werden. Ist die traditionelle staatliche Bereitstellung noch gerechtfertigt? Wie weit sollte eine Autobahnprivatisierung gehen? --

    Seasonal changes in brain serotonin transporter binding in short 5-HTTLPR-allele carriers but not in long-allele homozygotes

    Get PDF
    Several findings suggest seasonal variations in the serotonin (5-HT) system. We sought evidence for seasonal variation in the serotonin transporter (5-HTT). We found that length of daylight time in minutes correlates negatively with 5-HTT binding in the putamen and the caudate, with a similar tendency in the thalamus, but no such association in the midbrain. In the putamen, an anatomical region with a dense serotonin innervation that is implicated in processing of aversive stimuli, we found a significant gene*daylight effect with a negative correlation between the 5-HTT binding and daylight time in carriers of the short 5-HTTLPR allele, but not in carriers of the long allele. The neurobiological endophenotype identified here directly links activation studies, showing responses on the neural circuit level, with dynamic changes in transporter expression measured in vivo

    Apparatus in the form of a disk for the separation of oxygen from other gases and/or for the pumping of oxygen and the method of removing the oxygen

    Get PDF
    An apparatus in the form of a disk for the separation of oxygen from gases, or for the pumping of oxygen, uses a substantially circular disk geometry for the solid electrolyte with radial flow of gas from the outside edge of the disk to the center of the disk. The reduction in available surface area as the gas flows toward the center of the disk reduces the oxygen removal area proportionally to provide for a more uniform removal of oxygen

    High-Transmission-Efficiency and Side-Viewing Micro OIDRS Probe for Fast and Minimally Invasive Tumor Margin Detection

    Get PDF
    The determination of a cancer free margin I organ is a difficult and time consuming process, with an unmet need for rapid determination of tumor margin at surgery. In this paper, we report the design, fabrication, and testing of a novel miniaturized optical sensor probe with “side-viewing” capability. Its unprecedented small size, unique “side-viewing” capability, and high optical transmission efficiency enable the agile maneuvering and efficient data collection even in the narrow cavities inside the human body. The sensor probe consists of four micromachined substrates with optical fibers for oblique light incidence and collection of spatially resolved diffuse reflectance from the contacted tissues. The optical sensor probe has been used to conduct the oblique incidence diffuse reflectance spectroscopy (OIDRS) on a human pancreatic specimen. Based on the measurement results, the margin of the malignant tumor has been successfully determined optically, which matches well with the histological results
    corecore