Development and demonstration of flueric sounding rocket motor ignition

An analytical and experimental program is described which established a flueric rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source. An evaluation was made of this concept to determine the margins of the operating range and capabilities of every component of the system. This evaluation included a determination of power supply requirements, ignitor geometry and alinement, ignitor/propellant interfacing and materials and the effects of ambient temperatures and pressure. It was demonstrated that an operator using a simple hand pump for 30 seconds could ignite BKNO3 at a standoff distance of 100 m (330 ft) with the only connection to the ignitor being a piece of plastic pneumatic tubing

A multi-material transport problem and its convex relaxation via rectifiable GG-currents

In this paper we study a variant of the branched transportation problem, that we call multi-material transport problem. This is a transportation problem, where distinct commodities are transported simultaneously along a network. The cost of the transportation depends on the network used to move the masses, as it is common in models studied in branched transportation. The main novelty is that in our model the cost per unit length of the network does not depend only on the total flow, but on the actual quantity of each commodity. This allows to take into account different interactions between the transported goods. We propose an Eulerian formulation of the discrete problem, describing the flow of each commodity through every point of the network. We provide minimal assumptions on the cost, under which existence of solutions can be proved. Moreover, we prove that, under mild additional assumptions, the problem can be rephrased as a mass minimization problem in a class of rectifiable currents with coefficients in a group, allowing to introduce a notion of calibration. The latter result is new even in the well studied framework of the "single-material" branched transportation.Comment: Accepted: SIAM J. Math. Ana

Ignition of sounding rocket motors with hand-pumped air

Method demonstrates inexpensive, safe, and foolproof concept for solid propellant rocket motors, using simple handpump to deliver air. Flueric ignition was accomplished using system without stored energy and with complete absence of electrical energy and wiring

Speech Communication

Contains reports on one research project.U. S. Air Force (Electronic Systems Division) under Contract AF 19(604)-6102National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-03

GALEX measurements of the Big Blue Bump as a tool to study bolometric corrections in AGNs

Active Galactic Nuclei emit over the entire electromagnetic spectrum with the peak of the accretion disk emission in the far-UV, a wavelength range historically difficult to investigate. We use here the GALEX (Galaxy Evolution Explorer) Near-UV and Far-UV measurements (complemented with optical data from Sloan Digital Sky Survey (SDSS) and XMM-Newton X-ray spectra) of a sample of 83 X-ray selected type 1 AGN extracted from the XMM-Newton Bright Serendipitous Survey to study their spectral energy distribution (SED) in the optical, Near and Far-UV and X-ray energy bands. We have constrained the luminosity of the accretion disk emission component and calculated the hard X-ray bolometric corrections for a significant sample of AGN spanning a large range in properties (z, L(x)).Comment: 2 pages, 2 figures, To appear in refereed Proceedings of "X-ray Astronomy 2009: Present Status, Multi-Wavelength Approach and Future Perspectives", Bologna, Italy, September 7-11, 2009, AIP, eds. A. Comastri, M. Cappi, and L. Angelin

Cognitive Work Analysis for Domain Analysis in an HR Firm: Emergent Vocabulary to Domain Ontology

Cognitive Work Analysis (CWA) is a promising qualitative empirical method for domain analysis (Fidel and Pejtersen 2004). In this lightning paper we report some of the results of a recent study of the organizational environment and knowledge organization structures of a boutique human resources consulting firm (Marchese 2012)

Treatment of esophageal achalasia in children: Today and tomorrow

Esophageal achalasia (EA) is a rare esophageal motility disorder in children. Laparoscopic Heller myotomy (LHM) represents the treatment of choice in young patients. Peroral endoscopic myotomy (POEM) is becoming an alternative to LHM. The aim of this study is to evaluate the effectiveness, safety, and outcomes of POEM vs LHM in treatment of children with EA. Data of pediatric patients with EA, who underwent LHM and POEM from February 2009 to December 2013 in two centers, were collected. Eighteen patients (9 male, mean age: 11.6 years; range: 2-17 years) were included. Nine patients (6 male, mean age: 10.7 years; range: 2-16 years) underwent LHM, and the other 9 (3 males, mean age: 12.2 years; range: 6-17 years) underwent POEM procedure. Mean operation time was shorter in POEM group compared with LHM group (62/149 minutes). Myotomy was longer in POEM group than in LHM group (11/7 cm). One major complication occurred after LHM (esophageal perforation). No clinical and manometric differences were observed between LHM and POEM in follow-up. The incidence of iatrogenic gastroesophageal reflux disease was low (1 patient in both groups). Results of a midterm follow-up show that LHM and POEM are safe and effective treatments also in children. Besides, POEM is a mini-invasive technique with an inferior execution timing compared to LHM. A skilled endoscopic team is mandatory to perform this procedur

Complex cardiac surgery in a high-risk patient with new-onset severe mitral regurgitation and aorta to right ventricular fistula after transcatheter aortic valve implantation: a case report.

Transcatheter aortic valve implantation (TAVI) is the procedure of choice for aortic stenosis in high surgical risk patients, but it is no free from complications. A 86-year-old patient with severe aortic stenosis underwent TAVI 3 years ago with an Edwards Sapiens valve by femoral access. In the echocardiography follow-up, an aorta-right ventricular (Ao-RV) fistula was noted with restrictive flow and no significant shunt and it was treated conservatively. Three years after TAVI, the patient underwent cardiac surgery because of worsening heart failure due to a severe degenerative mitral regurgitation with tethering of P2 due to left ventricular remodelling, a posterior jet of severe regurgitation, and left ventricular dilatation. Surgical replacement of the TAVI and aortic root with a bioprosthesis (Medtronic Freestyle) and direct closure of the fistula was performed along with the mitral valve replacement. The patient was discharged with a good clinical result and no evidence of remaining Ao-RV fistula at transthoracic echocardiography. Aorta-right ventricular fistula is a rare entity. Most reported cases arise after rupture of a congenital coronary sinus aneurism, endocarditis, trauma, and aortic valve or aortic root surgery. This is the 10th reported case after TAVI (9 after an Edwards Sapiens TAVI). Non-significant shunt can be treated conservatively but development of heart failure and death are described in significant shunts. Balloon post-dilatation and the absence of surgical calcium debridement inherent to TAVI may theoretically contribute to the development of the fistula. Surgical replacement and closure of the fistula is a therapeutic option for this entity even in high-risk patients