Fuel-injector/air-swirl characterization

The objectives of this program are to establish an experimental data base documenting the behavior of gas turbine engine fuel injector sprays as the spray interacts with the swirling gas flow existing in the combustor dome, and to conduct an assessment of the validity of current analytical techniques for predicting fuel spray behavior. Emphasis is placed on the acquisition of data using injector/swirler components which closely resemble components currently in use in advanced aircraft gas turbine engines, conducting tests under conditions that closely simulate or closely approximate those developed in actual combustors, and conducting a well-controlled experimental effort which will comprise using a combination of low-risk experiments and experiments requiring the use of state-of-the-art diagnostic instrumentation. Analysis of the data is to be conducted using an existing, TEACH-type code which employs a stochastic analysis of the motion of the dispersed phase in the turbulent continuum flow field

Combustion of coal gas fuels in a staged combustor

Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented

Lean Stability augmentation study

An analytical and experimental program was conducted to investigate techniques and develop technology for improving the lean combustion limits of premixing, prevaporizing combustors applicable to gas turbine engine main burners. Three concepts for improving lean stability limits were selected for experimental evaluation among twelve approaches considered. Concepts were selected on the basis of the potential for improving stability limits and achieving emission goals, the technological risks associated with development of practical burners employing the concepts, and the penalties to airline direct operating costs resulting from decreased combustor performance, increased engine cost, increased maintenance cost and increased engine weight associated with implementation of the concepts. Tests of flameholders embodying the selected concepts were conducted

Modeling of premixing-prevaporizing fuel-air mixing passages

The development of a computer program for the analytical prediction of the distribution of liquid and vapor fuel in the premixing-prevaporizing passage by the direct injection method is described. The technical approach adopted for this program is to separate the problem into three parts each with its own computer code. These three parts are: calculation of the two-dimensional or axisymmetric air flow; calculation of the three-dimensional fuel droplet evaporation; and calculation of the fuel vapor diffusion. This method of approach is justified because premixing passages operate at lean equivalence ratios. Hence, a weak interaction assumption can be made wherein the airflow can affect the fuel droplet behavior but the fuel droplet behavior does not affect the airflow

Analytical modeling of operating characteristics of premixing-prevaporizing fuel-air mixing passages. Volume 2: User's manual

A user's manual describing the operation of three computer codes (ADD code, PTRAK code, and VAPDIF code) is presented. The general features of the computer codes, the input/output formats, run streams, and sample input cases are described

Role of Src homology domain binding in signaling complexes assembled by the murid γ-herpesvirus M2 protein

γ-Herpesviruses express proteins that modulate B lymphocyte signaling to achieve persistent latent infections. One such protein is the M2 latency-associated protein encoded by the murid herpesvirus-4. M2 has two closely spaced tyrosine residues, Tyr120 and Tyr129, which are phosphorylated by Src family tyrosine kinases. Here we used mass spectrometry to identify the binding partners of tyrosine-phosphorylated M2. Each M2 phosphomotif is shown to bind directly and selectively to SH2-containing signaling molecules. Specifically, Src family kinases, NCK1 and Vav1, bound to the Tyr(P)120 site, PLCγ2 and the SHP2 phosphatase bound to the Tyr(P)129 motif, and the p85α subunit of PI3K associated with either motif. Consistent with these data, we show that M2 coordinates the formation of multiprotein complexes with these proteins. The effect of those interactions is functionally bivalent, because it can result in either the phosphorylation of a subset of binding proteins (Vav1 and PLCγ2) or in the inactivation of downstream targets (AKT). Finally, we show that translocation to the plasma membrane and subsequent M2 tyrosine phosphorylation relies on the integrity of a C-terminal proline-rich SH3 binding region of M2 and its interaction with Src family kinases. Unlike other γ-herpesviruses, that encode transmembrane proteins that mimic the activation of ITAMs, murid herpesvirus-4 perturbs B cell signaling using a cytoplasmic/membrane shuttling factor that nucleates the assembly of signaling complexes using a bilayered mechanism of phosphotyrosine and proline-rich anchoring motifs.This work was supported by Portuguese Fundação para a Ciência e Tecnologia (FCT) Grant PTDC/SAU-MII/099314/2008 (to J. P. S.) and Spanish Association Against Cancer and Spanish Ministry of Economy and Competitiveness Grants SAF2009-07172 and RD06/0020/0001, respectively (to X. R. B.). Spanish funding is co-sponsored by the European FEDER program. The SPR equipment at the Instituto de Tecnologia Química e Biológica was acquired with FCT Grant PNRC/692/BIO/2264/2005.Peer Reviewe

Overtone production of soft x-rays with free-electron lasers

Two one-dimensional free-electron laser codes have recently been written that include harmonic generation. A comparison of the results of these codes show that a self-consistent treatment of the harmonic interaction is not required in the presence of a strong fundamental field. Use of these codes to predict the effects of emittance on harmonic production have been conducted. The effects of wiggler-field amplitude fluctuations and odd-harmonic wiggler-field components on the harmonic-radiation production are also discussed

Air ambulance flights in northern Norway 2002-2008. Increased number of secondary fixed wing (FW) operations and more use of rotor wing (RW) transports

Air ambulance service in Norway has been upgraded during the last years. European regulations concerning pilots’ working time and new treatment guidelines/strategies have called for more resources. The objective was to describe and analyse the two supplementary air ambulance [fixed wing (FW) and rotor wing (RW)] alternatives’ activity during the study period (2002-2008). Furthermore we aimed to compare our findings with reports from other north European regions. This is a retrospective analysis. The air ambulance fleet’s activity according to the electronic patient record database of “Luftambulansetjenesten ANS” (LABAS) was analysed. The subject was the fleet’s operations in northern Norway, logistics, and patients handled. Type of flight, distances, frequency, and patients served were the main outcome measures. A significant increase (45%) in the use of RW and a shift in FW operations (less primary and more secondary) were revealed. The shift in FW operations reflected the centralisation of several health care services [i.e. percutaneous cardiac intervention (PCI), trauma, and cancer surgery] during the study period. Cardiovascular disease (CVD) and injuries were the main diagnoses and constituted half of all operations. CVD was the most common cause of FW operations and injuries of the RW ones. The number of air ambulance operations was 16 per 1,000 inhabitants. This was more frequent than in other north European regions. The use of air ambulances and especially RW was significantly increased during the study period. The change in secondary FW operations reflected centralisation of medical care. When health care services are centralised, air ambulance services must be adjusted to the new settings

Air ambulance services in the Arctic 1999-2009 : a Norwegian study.

Air ambulance services in the Arctic have to deal with remote locations, long distances, rough weather conditions and seasonable darkness. Despite these challenges, the people living in the area expect a high quality of specialist health care. The objective of this study was to analyse the air ambulance operations performed in the Norwegian Arctic and study variations in diagnoses and flight patterns around the year. A retrospective analysis. All air ambulance operations performed during the time 1999 – 2009 period were analysed. The subjects were patients transported and flights performed. The primary outcome measures were patients’ diagnoses and task patterns around the year. A total of 345 patients were transported and 321 flights performed. Coronary heart and vascular disease, bone fractures and infections were the most common diagnoses. Most patients (85%) had NACA score 3 or 4. Half of all fractures occurred in April and August. Most patients were males (66%), and one fourth was not Norwegian. The median flying time (one way) was 3 h 33 m. Ten percent of the flights were delayed, and only 14% were performed between midnight and 8.00 AM. The period April to August was the busiest one (58% of operations). Norway has run a safe air ambulance service in the Arctic for the last 11 years. In the future more shipping and polar adventure operations may influence the need for air ambulances, especially during summer and autumn