2,062 research outputs found
Steady, oscillatory, and unsteady subsonic Aerodynamics, production version 1.1 (SOUSSA-P1.1). Volume 2: User/programmer manual
A user/programmer manual for the computer program SOUSSA P 1.1 is presented. The program was designed to provide accurate and efficient evaluation of steady and unsteady loads on aircraft having arbitrary shapes and motions, including structural deformations. These design goals were in part achieved through the incorporation of the data handling capabilities of the SPAR finite element Structural Analysis computer program. As a further result, SOUSSA P possesses an extensive checkpoint/ restart facility. The programmer's portion of this manual includes overlay/subroutine hierarchy, logical flow of control, definition of SOUSSA P 1.1 FORTRAN variables, and definition of SOUSSA P 1.1 subroutines. Purpose of the SOUSSA P 1.1 modules, input data to the program, output of the program, hardware/software requirements, error detection and reporting capabilities, job control statements, a summary of the procedure for running the program and two test cases including input and output and listings are described in the user oriented portion of the manual
J/psi production at RHIC-PHENIX
The J/psi is considered to be among the most important probes for the
deconfined quark gluon plasma (QGP) created by relativistic heavy ion
collisions. While the J/psi is thought to dissociate in the QGP by Debye color
screening, there are competing effects from cold nuclear matter (CNM),
feed-downs from excited charmonia (chi_c and psi') and bottom quarks, and
regeneration from uncorrelated charm quarks. Measurements that can provide
information to disentangle these effects are presented in this paper.Comment: 4 pages, 3 figures, conference proceedings: the 20th International
Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter
2008, Jaipur (India), 4-10 February 2008, submitted to J. Phys. G: Nuclear
and Particle Physic
Aids and surgery
HIV constitutes one of the most difficult challenges facing the healthcare profession today. It is estimated that HIV infects over 40 million people in the world and 14 million have died from the disease so far. The objective of the study was to evaluate the outcome of treatment of HIV-related surgical conditions, estimating the morbidity and mortality of surgical intervention cross infection risks to surgical equipes and analysing preventive strategies to HIV perioperative transmission
Treatment of Lower-GI Post-Surgical Fistulas With the Over-the-Scope Clip
AbstractPost-surgical colorectal leaks and fistulas are severe complications that dramatically increase morbidity and mortality. Over-the-scope clip (OTSC) application, introduced in clinical practice in 2007, represents an innovative technique to seal the visceral wall for acute and chronic colorectal post-surgical leaks and fistula management. Endoscopic closure of colorectal post-surgical leaks and fistulas with OTSC is a safe technique that accomplishes a high success rate in both acute and chronic cases, including rectovaginal, rectovesical, and colocutaneous fistulas. Overall success rate is higher than 80%, as reported in the literature, in both acute and chronic situations. No OTSC-related complications have been described in the lower gastrointestinal tract so far. This article is part of an expert video encyclopedia
A magnetic internal mechanism for precise orientation of the camera in wireless endoluminal applications
Background and study aims: The use of magnetic
fields to control operative devices has been recently
described in endoluminal and transluminal
surgical applications. The exponential decrease of
magnetic field strength with distance has major
implications for precision of the remote control.
We aimed to assess the feasibility and functionality
of a novel wireless miniaturized mechanism,
based on magnetic forces, for precise orientation
of the camera.
Materials and methods: A remotely controllable
endoscopic capsule was developed as proof of
concept. Two intracapsular moveable permanent
magnets allow fine positioning, and an externally
applied magnetic field permits gross movement
and stabilization. Performance was assessed in ex
vivo and in vivo bench tests, using porcine upper
and lower gastrointestinal tracts.
Results: Fine control of capsule navigation and
rotation was achieved in all tests with an external
magnet held steadily about 15 cm from the capsule.
The camera could be rotated in steps of 1.8°.
This was confirmed by ex vivo tests; the mechanism
could adjust the capsule view at 40 different
locations in a gastrointestinal tract phantom
model. Full 360° viewing was possible in the gastric
cavity, while the maximal steering in the colonwas
45° in total. In vivo, a similar performance
was verified, where the mechanism was successfully
operated every 5 cm for 40 cm in the colon,
visually sweeping from side to side of the lumen;
360° views were obtained in the gastric fundus
and body, while antrally the luminal walls prevented
full rotation.
Conclusions: We report the feasibility and effectiveness
of the combined use of external static
magnetic fields and internal actuation to move
small permanent intracapsular magnets to
achieve wirelessly controllable and precise camera
steering. The concept is applicable to capsule
endoscopy as to other instrumentation for laparoscopic,
endoluminal, or transluminal procedures
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Low density molecular gas in the galaxy
The distributions and physical conditions in molecular gas in the interstellar medium have been investigated in both the Galaxy and towards external galaxies. For example, Galactic plane surveys in the CO J =1-0 line with the Columbia 1.2-m telescope and with the Five College Radio Astronomy Observatory (FCRAO) 14-m telescopes have been able to trace spiral arms more clearly than HI surveys have been able to reveal, and indicate that most of molecular mass is contained in Giant Molecular Clouds (GMCs). Extensive maps of the whole Milky Way showed two prominent features, the 4-kpc molecular ring and the Galactic center. The physical conditions in the Galaxy have been studied by comparing the intensity of CO J =1-0 line with those of other lines, e.g., 13CO J =1-0, higher J transitions of CO, and dense gas tracers such as HCO+, CS, and HCN.
Previous studies were however strongly biased towards regions where CO emission was known to be intense. The radial distribution of molecular hydrogen shows that most of the H2 gas which is indirectly traced by observations of its associated CO emission, originates from the inner Galaxy (Dame 1993). Extending outwards from a galacto-centric distance of ~7 kpc, the H2 mass surface density decreases dramatically, and HI dominates over H2 in the outer Galaxy. What are physical conditions of molecular gas where the CO emission is relatively weak, and can we really trace all of the molecular gas through obervations of CO? These kinds of problems have not been solved yet, but are addressed in our study
Modification of Caloris ejecta blocks by long-lived mass-wasting: A volatile-driven process?
The Caloris basin is the largest well-preserved impact basin on Mercury. As such, Caloris ejecta afford us an opportunity to study material from Mercury’s deep interior with remote sensing. We have made observations of the geomorphology, colour, distribution, and flank slopes of the circum-Caloris knobs. Our observations suggest that these circum-Caloris knobs are modified ejecta blocks from the Caloris impact. High-resolution MESSENGER images show that knobs are conical and relatively uncratered compared with the surrounding plains, which implies the knobs have undergone resurfacing. We have observed material that has sloughed off knobs superposing impact craters that demonstrably postdate the Caloris impact, which requires some knob modification to have been more recent. We have observed hollows, depressions in Mercury’s surface generally believed to have been caused by volatile-loss, on and closely associated with several knobs, which indicates that many knobs contain volatile material and that knob modification could extend into Mercury’s recent past. Our measurements show that knob flanks typically have slopes of ∼21°, which is steep for a mound of unconsolidated material that was originally emplaced ∼3.8 Ga. The conical shape of knobs, their steep slopes, the dearth of superposed craters on knobs, and knob superposition relationships with other landforms suggest that Caloris ejecta blocks of arbitrary original shape were modified into their present shapes by long-lived mass-wasting. Mass-wasting must have dominated over impact gardening, which would have produced domal morphologies only. We suggest that mass-wasting was probably driven by volatile-loss, in a manner analogous to terrestrial landforms called ‘molards’. If the circum-Caloris knobs are analogous to molards, then they represent a landform and a process hitherto undocumented on Mercury, with implications for the volatile content of the planet’s interior. These knobs therefore are prime targets for BepiColombo, which could search for fresh failures and volatile exposures in the knobs
Handover Algorithm based VLP using Mobility Prediction Database for Vehicular Network
This paper proposes an improved handover algorithm method for vehicle location prediction (VLP-HA) using mobility prediction database. The main advantage of this method is the mobility prediction database is based on real traffic data traces. Furthermore, the proposed method has the ability to reduce handover decision time and solve resource allocation problem. The algorithm is simple and can be computed very rapidly; thus, its implementation for a high-speed vehicle is possible. To evaluate the effectiveness of the proposed method, QualNet simulation is carried out under different velocity scenarios. Its performance is compared with conventional handover method. The superiority of the proposed method over conventional handover method in deciding the best handover location and choosing candidate access points is highlighted by simulation. It was found that VLP-HA has clearly reduced handover delay by 45% compared to handover without VLP, give high accuracy, hence low complexity algorithm
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