Evaluation of an Ejector Ramjet Based Propulsion System for Air-Breathing Hypersonic Flight

A Rocket Based Combined Cycle (RBCC) engine system is designed to combine the high thrust to weight ratio of a rocket along with the high specific impulse of a ramjet in a single, integrated propulsion system. This integrated, combined cycle propulsion system is designed to provide higher vehicle performance than that achievable with a separate rocket and ramjet. The RBCC engine system studied in the current program is the Aerojet strutjet engine concept, which is being developed jointly by a government-industry team as part of the Air Force HyTech program pre-PRDA activity. The strutjet is an ejector-ramjet engine in which small rocket chambers are embedded into the trailing edges of the inlet compression struts. The engine operates as an ejector-ramjet from take-off to slightly above Mach 3. Above Mach 3 the engine operates as a ramjet and transitions to a scramjet at high Mach numbers. For space launch applications the rockets would be re-ignited at a Mach number or altitude beyond which air-breathing propulsion alone becomes impractical. The focus of the present study is to develop and demonstrate a strutjet flowpath using hydrocarbon fuel at up to Mach 7 conditions. Freejet tests of a candidate flowpath for this RBCC engine were conducted at the NASA Lewis Research Center's Hypersonic Tunnel Facility between July and September 1996. This paper describes the engine flowpath and installation, outlines the primary objectives of the program, and describes the overall results of this activity. Through this program 15 full duration tests, including 13 fueled tests were made. The first major achievement was the further demonstration of the HTF capability. The facility operated at conditions up to 1950 K and 7.34 MPa, simulating approximately Mach 6.6 flight. The initial tests were unfueled and focused on verifying both facility and engine starting. During these runs additional aerodynamic appliances were incorporated onto the facility diffuser to enhance starting. Both facility and engine starting were achieved. Further, the static pressure distributions compared well with the results previously obtained in a 40% subscale flowpath study conducted in the LERC 1X1 supersonic wind tunnel (SWT), as well as the results of CFD analysis. Fueled performance results were obtained for the engine at both simulated Mach 6 (1670 K) and Mach 6.6 (1950 K) conditions. For all these tests the primary fuel was liquid JP-10 with gaseous silane (a mixture of 20% SiH4 and 80% H2 by volume) as an ignitor/pilot. These tests verified performance of this engine flowpath in a freejet mode. High combustor pressures were reached and significant changes in axial force were achieved due to combustion. Future test plans include redistributing the fuel to improve mixing, and consequently performance, at higher equivalence ratios

Surgical correction of the wolff-parkinson-white syndrome in the closed heart using cryosurgery: A simplified approach

The conventional operation for ablation of accessory atrioventricular (AV) pathways in the Wolff-Parkinson-White syndrome requires an endocardial approach to the AV groove and necessitates the use of cardiopulmonary bypass and induced cardiac arrest. The feasibility of creating transmural atrial fibrosis at the level of the AV anulus in the closed heart in dogs without damaging the vascular contents of the AV fat pad was demonstrated. This was done by dissecting the fat pad from the atrium and applying a cryoprobe to the exposed atrial-anular region after retraction of the fat pad. The technique was then applied to successfully ablate 12 left parietal wall accessory pathways in 11 patients with the Wolff-Parkinson-White syndrome. This simplified approach to any parietal wall accessory pathway does not require cardiopulmonary bypass or induced cardiac arrest and may broaden the indications for this operation

Ex-formation as a method for mapping smellscapes

‘Every city, let me teach you, has its own smell.’ This quote, from an early chapter of E.M. Forster’s ‘A Room With a View’, points to a humanistic understanding of global urban smellscapes with the potential therein for shared understanding. Exploring options for the communication of Singapore’s ‘own smell’ this visual essay suggests how ‘ex-formation’ may be used as to probe one ontological view of the map…. The main characteristic of an ex-formation approach is ‘unlikely combination as suggestion’ e.g. tarmac roads in place of a river surface alluding to the changing scale of a river from trickle to delta, inedible organic matter packaged in white styrofoam with clear food product labelling suggesting a hygienic trust of shrink-wrapped food over natural produce, miniature underwear on inanimate objects suggesting that objects too might have nudity... Smell and visual is one such unlikely combination suggesting that invisible smell objects can be pervasive and imbued with colour

The High Voltage Feedthroughs for the ATLAS Liquid Argon Calorimeters

The purpose, design specifications, construction techniques, and testing methods are described for the high voltage feedthrough ports and filters of the ATLAS Liquid Argon calorimeters. These feedthroughs carry about 5000 high voltage wires from a room-temperature environment (300 K) through the cryostat walls to the calorimeters cells (89 K) while maintaining the electrical and cryogenic integrity of the system. The feedthrough wiring and filters operate at a maximum high voltage of 2.5 kV without danger of degradation by corona discharges or radiation at the Large Hadron Collider

2020-06-26/27/28 DAILY UNM GLOBAL HEALTH COVID-19 BRIEFING

Executive Summary: NM Highlights: State fair cancelled. Phase 2 reopening stalls. Fewer New Mexicans staying home. ABQ July 4 celebration plan. NM case update. US Highlights: Family members infected following surprise birthday party. New cases spike in Texas due to early reopening of bars. International Highlights: 50% in Austria ski resort have antibodies. Economics, Workforce, Supply Chain, PPE: Why people do not wear masks. Mask filtration efficiencies compared. Masks worn incorrectly. Ultraviolet-based biophotonic technologies. Improved mask designs. Mask wearing controversy. Epidemiology Highlights: Contamination through air flow paths. Contamination of wastewater circulation. Healthcare Policy Recommendations: Moralizing COVID-19 mitigation practices contributes to social polarization. Misperception of exponential infection growth by Americans is common but can be corrected. Adjust quarantine plans for the findings that older patients might have a longer incubation period. Hazards of school reopening in European countries with high transmission rates. Practice Guidelines: Several Brazilian recommendations are published on managing lung cancer, performing laparoscopic surgery, and breastfeeding. Guidelines are provided and managing gynecological cancer. Testing: Test accessibility, frequency and speed of reporting matters more than sensitivity. Prolonged shedding of SARS-CoV-2. Sensitivity of nasopharyngeal and swabs testing. Testing algorithm for essential workers. Drugs, Vaccines, Therapies, Clinical Trials: dexamethasone trial preprint criticized, smallpox-based COVID-19 vaccine, 27 new clinical trials. Other Science: Pandemic sees increased alcohol consumption. Charlson Comorbidity Index predicts poor outcomes. CT features associated with severity. Immune-inflammatory tests associated with severity. Hepatic complications

2020-05-16/17 DAILY UNM GLOBAL HEALTH COVID-19 BRIEFING

Executive Summary: Only 1 case in NM state prisons. NM case count. NM travel warning. NM web-based recovery reporting system. NM Mask Madness Tournament. Face covering in ABQ. NM graduate medical program funding. ABQ Memorial Day cancellation. NM affordable housing funding. Taos farmers market drive through opening. US correctional facility cases. Social distancing works. Dogs sniffing out COVID-19. Germany\u27s soccer league to restart. Mask effectiveness. Mask comfort w/cardboard cutout. Ammonium cleaning ineffective. CDC contact tracing guidance. Spanish immunity. CDC epidemic intelligence fellowship. Speaking transmits virus. Decontaminating workers. CDC advisory for children. Addressing ER fears. Indoor presymptomatic virus transfer. Virus transmission of currency. Safety advice for reopening. Lessons learned from universities. Dutch safe sex guidelines for singles. Recommendations are given on invasive management of acute coronary syndrome, onco-gynecologic surgery, endoscopy, hemodialysis, on resuming orthopedic surgery, clozapine monitoring, starting ADHD medications, orthodontics, and scaling up virtual services. At-home sample collection kit. Hydroxychloroquine no benefit. Tocilizumab reduces mortality rate. Calcium channel blockers beneficial. COVID-19 opinion/review vs. primary research. Disease severity and biomarkers. Concomitant liver injury. Gastrointestinal and liver involvement. Diabetes mortality. High incidence venous thrombosis. Monitoring global emotions with twitter