49 research outputs found

    Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning natural gas

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    An annular gas turbine combustor was tested with heated natural gas fuel to determine the effect of increasing fuel temperature on the formation of oxides of nitrogen. Fuel temperatures ranged from ambient to 800 K (980 F). Combustor pressure was 6 atmospheres and the inlet air temperature ranged from 589 to 894 K (600 to 1150 F). The NOx emission index increased with fuel temperature at a rate of 4 to 9 percent per 100 K (180 F), depending on the inlet air temperature. The rate of increase in NOx was lowest at the highest inlet air temperature tested

    Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning ASTM jet-A fuel

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    An annular gas turbine combustor was tested with heated ASTM Jet-A fuel to determine the effect of increased fuel temperature on the formation of oxides of nitrogen. Fuel temperature ranged from ambient to 700 K. The NOx emission index increased at a rate of 6 percent per 100 K increase in fuel temperature

    Effect of water injection on nitric oxide emissions of a gas turbine combustor burning natural gas fuel

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    The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not

    The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

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    Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection

    Pentanol isomer synthesis in engineered microorganisms

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    Pentanol isomers such as 2-methyl-1-butanol and 3-methyl-1-butanol are a useful class of chemicals with a potential application as biofuels. They are found as natural by-products of microbial fermentations from amino acid substrates. However, the production titer and yield of the natural processes are too low to be considered for practical applications. Through metabolic engineering, microbial strains for the production of these isomers have been developed, as well as that for 1-pentanol and pentenol. Although the current production levels are still too low for immediate industrial applications, the approach holds significant promise for major breakthroughs in production efficiency

    Evaluation of the Applicability of IHSDM Crash Prediction Module on Italian Two-Lane Rural Roads

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    Reducing accidents on highways has always been one of the most important tasks for highway engineers. Estimating the number of accidents that may result from a given highway design is important in evaluating different alternatives. For this purpose the FHWA developed the Interactive Highway Safety Designs Model (IHSDM), a suite of software for analyzing two-lane rural highways in the United States. A key component of IHSDM is the Crash Prediction Module (CPM), which estimates the number of accidents on road segments. CPM was applied to two actual Italian two-lane rural roads to evaluate its capability to produce reasonably reliable crash predictions in the Italian context. The results of the case study showed considerable differences between the crash predicted and the crash data, underlining the difficulty of transferring this tool to the Italian context

    Petroleum residue upgrading with dispersed catalysts Part 2. Effect of operating conditions

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    The hydrotreatment of a petroleum residue in the presence of dispersed molybdenite was carried out within a wide range of operating conditions and catalyst loading. The effect of reaction severity as well as of molybdenum concentration on product distribution and quality was studied. Based on the experimental results, a simplified reaction scheme was proposed. The hydroprocessing of the residue was described in terms of the competition between two reactions: the direct conversion of the feedstock to distillate and coke, and the catalytic hydrogenation. Compared to thermal conditions, the presence of dispersed molybdenite controls very well coke formation; however, a trend of increasing formation of solids was observed at high catalyst concentrations. The overall upgrading of the feedstock requires significant amounts of molybdenum as well as relatively high hydrogen pressure

    Wearable artificial kidney and wearable ultrafiltration device vascular access-future directions

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    Background: Since 2005, three human clinical trials have been performed with the Wearable Artificial Kidney (WAK) and Wearable Ultrafiltration (WUF) device. The lack of an adequate vascular access (VA) has been pointed out as the main limitation to their implementation. Based on the current level of understanding, we will make the first conceptual proposal of an adequate VA suitable for the WAK and the WUF. Methods: All the literature related to WAK and WUF was reviewed. Based on eight main publications the VA major characteristics were defined: a mean blood flow of 100 mL/min; the capability to allow prolonged and frequent dialysis treatments, without interfering in activities of daily living (ADL); safe and convenient connection/disconnection systems; reduced risk of biofilm formation and coagulation; high biocompatibility. A research was done in order to answer to each necessary technological prerequisites. Results: The use of a device similar to a CVC with a 5Fr lumen, seems to be the most feasible option. Totally subcutaneous port devices, like the LifeSite(R) or Dialock (R) systems can be a solution to allow WAK or WUF to operate continuously while patients carry out their ADL. Recently, macromolecules that reduce the risk of thrombosis and infection and are integrated into a CVC have been developed and have the capability of overcoming these major limitations. Conclusion: With an adequate VA, portable HD devices can be acceptable options to address several unmet clinical needs of HD patients.info:eu-repo/semantics/publishedVersio
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