Effect of fuel molecular structure on soot formation in gas turbine combustion

The effect of fuel variations at the same hydrogen content on the formation of soot in a gas turbine combustor was studied. Six fuels were burned to a combustor over a matrix of about 50 test conditions with test conditions ranging over 500-1800 kPa (5-18 atm) pressure and 500-1000 K burner inlet temperature; fuel-air ratios were varied from 0.008-0.024. Flame radiation measurements were made through a sapphire window toward the end of the primary zone. The hydrogen content of the six test fuels ranged from 12.80 to 12.88%. Five fuels emphasized hydrocarbon types: (mono, di, and tricyclic), naphthenes (decalin) and partially hydrogenated aromatics (tetralin); the sixth fuel emphasized final boiling point

Fuel quality combustion analysis

A high pressure research combustor operating over a wide range of burner inlet conditions was used to determine the effects of fuel molecular structure on soot formation. Six test fuels with equal hydrogen content (12.8%) were blended to stress different molecular components and final boiling points. The fuels containing high concentrations (20%) of polycyclic aromatics and partially saturated polycyclic structures such as tetralin, produced more soot than would be expected from a hydrogen content correlation for typical petroleum based fuels. Fuels containing naphthenes such as decalin agreed with the hydrogen content correlation. The contribution of polycyclic aromatics to soot formation was equivalent to a reduction in fuel hydrogen content of about one percent. The fuel sensitivity to soot formation due to the polycyclic aromatic contribution decreased as burner inlet pressure and fuel/air ratio increased

Low-perigee aerodynamic heating during orbital flight of an atmosphere Explorer

An extensive, low-perigee orbital aerodynamic heating study was undertaken in support of the Atmosphere Explorer-C Temperature Alarm. State of the art of low-density, high-speed flows, some models of the earth's atmosphere, external flow-field definition, thermodynamic and transport properties of atmospheric gases, the accommodation coefficient orbital thermal environment, and correlation of theory and measurements are discussed. Aerodynamic heating rates are determined for eight selected orbits by means of a reduced, analytical model verified by both ground test and flight data. These heating rates are compared with classical free-molecule and first-order collision regime values

Revealing four decades of snow cover dynamics in the Hindu Kush Himalaya

Knowledge about the distribution and dynamics of seasonal snow cover (SSC) is of high importance for climate studies, hydrology or hazards assessment. SSC varies considerably across the Hindu Kush Himalaya both in space and time. Previous studies focused on regional investigations or the influence of snow melt on the local hydrological system. Here, we present a systematic assessment of metrics to evaluate SSC dynamics for the entire HKH at regional and basin scale based on AVHRR GAC data at a 0.05° spatial and daily temporal resolution. Our findings are based on a unique four-decade satellite-based time series of snow cover information. We reveal strong variability of SSC at all time scales. We find significantly decreasing SSC trends in individual summer and winter months and a declining tendency from mid-spring to mid-fall, indicating a shift in seasonality. Thanks to this uniquely spatio-temporally resolved long-term data basis, we can particularly highlight the unique temporally variable character of seasonal snow cover and its cross-disciplinary importance for mountain ecosystems and downstream regions

Prolonged decrease in heart rate variability after elective hip arthroplasty

The pattern of postoperative heart rate variability may provide insight into the response of the autonomic nervous system to anaesthesia and surgery. We have obtained spectral (fast Fourier transform) and non-spectral indices of heart rate variability from electrocardiographic recordings, sampled during continuous perioperative Holter monitoring in 15 otherwise healthy patients with an uncomplicated postoperative course, undergoing elective hip arthroplasty with either spinal or general anaesthesia. In both groups, total spectral energy (0.01-1 Hz), low-frequency spectral energy (0.01-0.15 Hz) and high-frequency spectral energy (0.15-0.40 Hz) decreased after surgery to 32% (95% confidence interval (Cl) 10.5; P <0.01), 29% (95% Cl 12.5; P <0.07; and 33% (95% Cl 12.5; P <0.01) of their preoperative values, respectively, and these indices remained suppressed for up to 5 days. Non-spectral indices decreased to a similar extent. These findings indicate a substantial and prolonged postoperative decrease in both parasympathetic and sympathetic influence on the sinus nod

Ergebnisse einer Umfrage zur ­Verschreibung von Antibiotika in der ­Veterinärmedizin

English Outcome of a survey on antibiotic prescribing in veterinary medicine As part of the national strategy on antibiotic resistance (StAR), a therapy guide for the prudent prescription of antimicrobial agents in animals was developed. To facilitate its implementation in the veterinary practice, the therapy recommendations contained therein have been translated to the user-friendly decision support AntibioticScout.ch. In this context, we conducted a non-representative survey to assess the level of awareness as well as usage of this guide and the AntibioticScout.ch decision support. Based on case studies with typical diseases in dogs, cats and cattle, it was shown that the veterinarians participating in the survey strive to handle antibiotics responsibly and to prescribe them with restraint. Nevertheless, the survey points to possible improvements in the antibiotic therapy. In particular, the StAR guidelines or AntibioticScout.ch can be useful to the practicing veterinarians for taking into account all relevant decision criteria in the optimal selection of a suitable antimicrobial agent. Keywords: AntibioticScout; Decision support; Prescribing behavior; Survey; Veterinary medicine Deutsch Ergebnisse einer Umfrage zur ­Verschreibung von Antibiotika in der ­Veterinärmedizin Im Rahmen der nationalen Strategie Antibiotikaresistenzen (StAR) wurde ein Therapieleitfaden für die umsichtige Verschreibung von antimikrobiellen Wirkstoffen bei Tieren erarbeitet. Um dessen Umsetzung in der tierärztlichen Praxis zu erleichtern, sind die darin enthaltenen Therapieempfehlungen in die benutzerfreundliche Entscheidungshilfe AntibioticScout.ch überführt worden. In diesem Zusammenhang haben wir eine nicht-repräsentative Umfrage durchgeführt um Bekanntheitsgrad und Nutzung dieses Leitfadens bzw. der Entscheidungshilfe AntibioticScout.ch einzuschätzen. Anhand von Fallbeispielen mit typischen Erkrankungen bei Hunden, Katzen und Rindern zeigte sich, dass die an der Befragung teilnehmenden Tierärztinnen und Tierärzte bestrebt sind, verantwortungsvoll mit Antibiotika umzugehen und diese Wirkstoffe zurückhaltend zu verschreiben. Trotzdem weist die Umfrage auf Verbesserungsmöglichkeiten in der Antibiotikatherapie hin. Der StAR-Therapieleitfaden und AntibioticScout.ch können insbesondere für die Berücksichtigung aller relevanten Entscheidungskriterien bei der optimalen Auswahl eines geeigneten antimikrobiellen Wirkstoffes der Tierärzteschaft dienlich sein. Schlüsselwörter: AntibioticScout; Entscheidungshilfe; ­Umfrage; Verschreibungsverhalten; Veterinärmedizin Français Résultats d’une enquête sur la ­prescription d’antibiotiques en ­médicine vétérinaire Dans le cadre de la stratégie nationale de résistance aux antibiotiques (StAR), un guide thérapeutique pour la prescription prudente d'agents antimicrobiens chez les animaux a été élaboré. Pour faciliter son application dans la pratique vétérinaire, les recommandations thérapeutiques qu'il contient ont été transférées dans l'aide à la décision conviviale en-ligne AntibioticScout.ch. Dans ce contexte, nous avons mené une enquête non représentative pour évaluer le niveau de connaissance et l’utilisation de ce guide de l'aide à la decision AntibioticScout.ch. Sur la base d'études de cas portant sur des maladies typiques des chiens, des chats et des bovins, il a été démontré que les vétérinaires participant à l'enquête s'efforcent d’ utiliser les antibiotiques de manière responsable et de les prescrire avec modération. Néanmoins, l'enquête met en évidence les améliorations possibles de la thérapie antibiotique. Le guide thérapeutique StAR ou AntibioticScout.ch peut être particulièrement utile à la profession vétérinaire pour prendre en compte tous les critères de décision pertinents dans la sélection optimale d'un agent antimicrobien approprié. Mots-clés: AntibioticScout; aide à la décision; enquéte; comportement de prescription; médecine vétérinaire Italiano Risultati di un sondaggio sulla ­prescrizione di antibiotici in medicina veterinaria Come parte della strategia nazionale di resistenza agli antibiotici (StAR), è stata sviluppata una guida terapeutica per la prescrizione prudente di agenti antimicrobici negli animali. Per facilitarne l'attuazione nella pratica veterinaria, le raccomandazioni terapeutiche ivi contenute sono state trasferite nell'aiuto decisionale di facile utilizzo AntibioticScout.ch. In questo contesto, abbiamo condotto un sondaggio non rappresentativo per valutare il livello di conoscenza e l’utilizzo di questa guida e del supporto decisionale AntibioticScout.ch. Sulla base di studi di casi con malattie tipiche di cani, gatti e bovini, è stato dimostrato che i veterinari che hanno partecipato all'indagine si sforzano di gestire gli antibiotici in modo responsabile e di prescriverli con moderazione. Tuttavia, il sondaggio indica possibili miglioramenti nella terapia antibiotica. La guida alla terapia StAR o AntibioticScout.ch può essere particolarmente utile ai professionisti veterinari per tenere conto di tutti i criteri decisionali rilevanti nella scelta ottimale di un agente antimicrobico adatto. Parole chiavi: AntibioticScout; supporto alle decisioni; sondaggio; comportamento prescrittivo; medicina veterinari

Annual post-market environmental monitoring (PMEM) report on the cultivation of genetically modified maize MON 810 in 2014 from Monsanto Europe S.A.

Following a request from the European Commission, the Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) assessed the annual post-market environmental monitoring (PMEM) report for the 2014 growing season of maize MON 810 provided by Monsanto Europe S.A. The GMO Panel concludes that the insect resistance monitoring data do not indicate a decrease in susceptibility of field Iberian populations of corn borers to the Cry1Ab protein over the 2014 season. However, as the methodology for insect resistance monitoring remained unchanged compared to previous PMEM reports, the GMO Panel reiterates its previous recommendations for improvement of the insect resistance management plan. The GMO Panel considers that the farmer alert system to report complaints regarding product performance could complement the information obtained from the laboratory bioassays, but encourages the consent holder to provide more information in order to be in a position to appraise its usefulness. The data on general surveillance activities do not indicate any unanticipated adverse effects on human and animal health or the environment arising from the cultivation of maize MON 810 cultivation in 2014. The GMO Panel reiterates its previous recommendations to improve the methodology for the analysis of farmer questionnaires and conduct of the literature review in future annual PMEM reports on maize MON 810. The GMO Panel urges the consent holder to consider how to make best use of the information recorded in national registers to optimise sampling for farmer questionnaires, and requests to continue reviewing and discussing relevant scientific publications on possible adverse effects of maize MON 810 on rove beetles. Also, the GMO Panel encourages relevant parties to continue developing a methodological framework to use existing networks in the broader context of environmental monitorin

Antimicrobial use for selected diseases in cats in Switzerland.

BACKGROUND Antibiotic use in human and veterinary medicine is considered a main driver of antimicrobial resistance. Although guidelines to promote appropriate use of antimicrobials in veterinary patients have been developed, antibiotic overprescription is assumed to be a common problem. The goal of this study was to investigate antimicrobial use in cats in Switzerland with acute upper respiratory tract disease (aURTD), feline lower urinary tract disease (FLUTD) and abscesses, and to assess compliance of prescription with consensus guidelines. A total of 776 cases (aURTD, n = 227; FLUTD, n = 333; abscesses, n = 216) presented to two university hospitals and 14 private veterinary practices in Switzerland during 2016 were retrospectively evaluated. Clinical history, diagnostic work-up and antimicrobial prescription (class, dosage, duration) were assessed. RESULTS A total of 77% (aURTD), 60% (FLUTD) and 96% (abscesses) of the cases received antibiotic therapy; 13-24% received combination or serial therapy. The cats were treated for a median of 7 (abscesses) and 10 days (aURTD, FLUTD). Treatments with potentiated aminopenicillins (40-64%), third generation cephalosporins (25-28%), aminopenicillins (12-24%) and fluoroquinolones (3-13%) were most common. Prescriptions were judged in complete accordance with consensus guidelines in 22% (aURTD), 24% (FLUTD) and 17% (abscesses) of the cases. Antibiotics were prescribed although not indicated in 34% (aURTD), 14% (FLUTD) and 29% (abscesses) of the cases. The presence of lethargy, anorexia or fever in cats with aURTD, and the detection of bacteriuria in cats with FLUTD were significantly associated with antibiotic therapy. Although diagnostic work-up was significantly more common (aURTD: university hospitals, 58%; private practices, 1%; FLUTD: university hospitals, 92%; private practices, 27%) and the use of critically important antibiotics significantly less common at the university hospitals (aURTD, 10%; FLUTD, 14%) compared to private practices (aURTD, 38%; FLUTD, 54%), the frequency of antibiotic treatment was not different between the university hospitals and private practices. CONCLUSIONS Our results indicate that overprescription of antibiotics in cats in Switzerland is common and accordance with guidelines is poor. The study highlights the need to promote antimicrobial stewardship in small animal medicine

Aquatic Hyphomycete Species Are Screened by the Hyporheic Zone of Woodland Streams

Aquatic hyphomycetes strongly contribute to organic matter dynamics in streams, but their abilities to colonize leaf litter buried in streambed sediments remain unexplored. Here, we conducted field and laboratory experiments (slow-filtration columns and stream-simulating microcosms) to test the following hypotheses: (i) that the hyporheic habitat acting as a physical sieve for spores filters out unsuccessful strategists from a potential species pool, (ii) that decreased pore size in sediments reduces species dispersal efficiency in the interstitial water, and (iii) that the physicochemical conditions prevailing in the hyporheic habitat will influence fungal community structure. Our field study showed that spore abundance and species diversity were consistently re- duced in the interstitial water compared with surface water within three differing streams. Significant differences occurred among aquatic hyphomycetes, with dispersal efficiency of filiform-spore species being much higher than those with compact or branched/tetraradiate spores. This pattern was remarkably consistent with those found in laboratory experiments that tested the influence of sediment pore size on spore dispersal in microcosms. Furthermore, leaves inoculated in a stream and incubated in slow-filtration columns exhibited a fungal assemblage dominated by only two species, while five species were codominant on leaves from the stream-simulating microcosms. Results of this study highlight that the hyporheic zone exerts two types of selec- tion pressure on the aquatic hyphomycete community, a physiological stress and a physical screening of the benthic spore pool, both leading to drastic changes in the structure of fungal community