568 research outputs found
Assessment of Aeroacoustic Simulations of the High-Lift Common Research Model
This paper presents further validation of PowerFLOWR aeroacoustic simulations of the High-Lift Common Research Model through comparisons with experimental data from a recently completed wind tunnel test. Preliminary time- averaged surface pressure and microphone array data from the experiment are in reasonably good agreement with the simulations, and the slat is shown to be a dominant noise source on this model. The simulations did not predict slat tones that were very prominent in the experiment, but they did capture the broadband component of slat noise in the low-frequency range up to 1 kHz at full scale. Future tests are planned to demonstrate slat noise reduction technology, and simulations are being used to guide this development
Preliminary Analysis of Acoustic Measurements from the NASA-Gulfstream Airframe Noise Flight Test
The NASA-Gulfstream joint Airframe Noise Flight Test program was conducted at the NASA Wallops Flight Facility during October, 2006. The primary objective of the AFN flight test was to acquire baseline airframe noise data on a regional jet class of transport in order to determine noise source strengths and distributions for model validation. To accomplish this task, two measuring systems were used: a ground-based microphone array and individual microphones. Acoustic data for a Gulfstream G550 aircraft were acquired over the course of ten days. Over twenty-four test conditions were flown. The test matrix was designed to provide an acoustic characterization of both the full aircraft and individual airframe components and included cruise to landing configurations. Noise sources were isolated by selectively deploying individual components (flaps, main landing gear, nose gear, spoilers, etc.) and altering the airspeed, glide path, and engine settings. The AFN flight test program confirmed that the airframe is a major contributor to the noise from regional jets during landing operations. Sound pressure levels from the individual microphones on the ground revealed the flap system to be the dominant airframe noise source for the G550 aircraft. The corresponding array beamform maps showed that most of the radiated sound from the flaps originates from the side edges. Using velocity to the sixth power and Strouhal scaling of the sound pressure spectra obtained at different speeds failed to collapse the data into a single spectrum. The best data collapse was obtained when the frequencies were left unscaled
Noise Simulations of the High-Lift Common Research Model
The PowerFLOW(TradeMark) code has been used to perform numerical simulations of the high-lift version of the Common Research Model (HL-CRM) that will be used for experimental testing of airframe noise. Time-averaged surface pressure results from PowerFLOW(TradeMark) are found to be in reasonable agreement with those from steady-state computations using FUN3D. Surface pressure fluctuations are highest around the slat break and nacelle/pylon region, and synthetic array beamforming results also indicate that this region is the dominant noise source on the model. The gap between the slat and pylon on the HL-CRM is not realistic for modern aircraft, and most nacelles include a chine that is absent in the baseline model. To account for those effects, additional simulations were completed with a chine and with the slat extended into the pylon. The case with the chine was nearly identical to the baseline, and the slat extension resulted in higher surface pressure fluctuations but slightly reduced radiated noise. The full-span slat geometry without the nacelle/pylon was also simulated and found to be around 10 dB quieter than the baseline over almost the entire frequency range. The current simulations are still considered preliminary as changes in the radiated acoustics are still being observed with grid refinement, and additional simulations with finer grids are planned
Spatial linear global instability analysis of the HIFiRE-5 elliptic cone model flow
The linear instability of the three-dimensional boundary-layer over the HIFiRE-5 flight test geometry, i.e. a rounded-tip 2:1 elliptic cone, at Mach 7, has been analyzed through spatial BiGlobal analysis, in a effort to understand transition and accurately predict local
heat loads on next-generation ight vehicles. The results at an intermediate axial section of the cone, Re x = 8x10 5, show three different families of spatially amplied linear global modes, the attachment-line and cross- ow modes known from earlier analyses, and a new global mode, peaking in the vicinity of the minor axis of the cone, termed \center-line mode". We discover that a sequence of symmetric and anti-symmetric centerline modes exist and, for the basic ow at hand, are maximally amplied around F* = 130kHz. The wavenumbers and spatial distribution of amplitude functions of the centerline modes are documente
Cross-site comparison of ribosomal depletion kits for Illumina RNAseq library construction
Background
Ribosomal RNA (rRNA) comprises at least 90% of total RNA extracted from mammalian tissue or cell line samples. Informative transcriptional profiling using massively parallel sequencing technologies requires either enrichment of mature poly-adenylated transcripts or targeted depletion of the rRNA fraction. The latter method is of particular interest because it is compatible with degraded samples such as those extracted from FFPE and also captures transcripts that are not poly-adenylated such as some non-coding RNAs. Here we provide a cross-site study that evaluates the performance of ribosomal RNA removal kits from Illumina, Takara/Clontech, Kapa Biosystems, Lexogen, New England Biolabs and Qiagen on intact and degraded RNA samples.
Results
We find that all of the kits are capable of performing significant ribosomal depletion, though there are differences in their ease of use. All kits were able to remove ribosomal RNA to below 20% with intact RNA and identify ~ 14,000 protein coding genes from the Universal Human Reference RNA sample at >1FPKM. Analysis of differentially detected genes between kits suggests that transcript length may be a key factor in library production efficiency.
Conclusions
These results provide a roadmap for labs on the strengths of each of these methods and how best to utilize them. Keywords: RNAseqr; RNA depletion; Illumina; NGS; ABRF; TranscriptomicsNational Cancer Institute (U.S.) (Grant P30-CA14051)National Institute of Environmental Health Sciences (Grant P30-ES002109
Minimally Invasive Osteosynthesis of Distal Tibia Fractures using Anterolateral Locking Plate
Introduction: Plating in distal tibia fractures are associated
with higher rate of soft tissue complications. As adequate
soft tissue cover is available over anterolateral surface of the
tibia, use of anterolateral plate fixation in distal tibia
fractures has increased. The purpose of our research is to
evaluate the outcomes of anterolateral locking plate fixation
in distal tibia fractures using ORIF.
Materials and Methods: A retrospective analysis of 25
patients, who had distal tibia fractures and underwent open
reduction and anterolateral plating. Bone and soft tissue
healing and complications encountered were analysed.
Result: Full weight bearing was allowed at an average of 5.4
months (range: 3-12 months) after seeing radiological union.
We have observed superficial wound infection in four cases.
Two cases had marginal necrosis, two cases had sensory
disturbance over dorsolateral aspect of foot and two cases
had delayed non-union. Mean length of surgical incision was
9cm (range: 5-12 cm).
Conclusion: Open reduction internal fixation of distal tibia
fractures with anterolateral plating is a reliable way of
fracture fixation and stabilisation with proper surgical
technique and aseptic precautions
Design and implementation of Cell Tracking system and Sync with cloud
In today?s world more than eighty percent people uses the smart phones. As the need increases the misuse of the cell phone also increases. Anyone can distrust or cheat other or suspicious of others activities. There may be loss of an important data in the big organizations due to the employees. Many criminal activities have increased in organization and teenagers are misusing the smart phones. So for the security purpose in the large organizations and to control the activities of the employees and the teenagers, software can be used which keeps the log files in a single mobile with its date and synchronize daily with restricted area in corporate with cloud
Numerical Evaluation of P-Multigrid Method for the Solution of Discontinuous Galerkin Discretizations of Diffusive Equations
This paper describes numerical experiments with P-multigrid to corroborate analysis, validate the present implementation, and to examine issues that arise in the implementations of the various combinations of relaxation schemes, discretizations and P-multigrid methods. The two approaches to implement P-multigrid presented here are equivalent for most high-order discretization methods such as spectral element, SUPG, and discontinuous Galerkin applied to advection; however it is discovered that the approach that mimics the common geometric multigrid implementation is less robust, and frequently unstable when applied to discontinuous Galerkin discretizations of di usion. Gauss-Seidel relaxation converges 40% faster than block Jacobi, as predicted by analysis; however, the implementation of Gauss-Seidel is considerably more expensive that one would expect because gradients in most neighboring elements must be updated. A compromise quasi Gauss-Seidel relaxation method that evaluates the gradient in each element twice per iteration converges at rates similar to those predicted for true Gauss-Seidel
Synthesis, Characterization and Quantification of Simvastatin Metabolites and Impurities
Simvastatin is used in treatment of hypercholesterolemia because it regulates cholesterol synthesis as a result of its β-hydroxy acid acting as an inhibitor of 3-hydroxy-methylglutaryl coenzyme A (HMG-CoA). The present communication deals with synthesis, characterization and development of accurate, precise and sensitive Reverse Phase High Performance Liquid Chromatography (RP-HPLC) method for simultaneous estimation of simvastatin and its synthetic impurities. The impurities methyl ether and β-hydroxy acid of simvastatin were synthesized in the laboratory and characterized by MS, NMR and FT-IR spectroscopy. The separation of simvastatin and its impurities was carried out on an isocratic JASCO RP-HPLC system using KYA TECH HIQ SIL C18 column (150 × 4.6 mm internal diameter, particle size 5 μm) operating at ambient temperature using acetonitrile:water (80:20 v/v) with 0.1% orthophosphoric acid as mobile phase. The method developed for HPLC analysis of three impurities along with simvastatin was validated using ICH Q2B (R1) guidelines and it complied with these guidelines. The results of analysis were found to be in the range of 98.14% to 101.89% for all analytes with acceptable accuracy and precision. The method can be used for detection and quantification of synthetic impurities in bulk or formulations of simvastatin
BER Analysis of Full Duplex Relay assisted BPSK-SIM based VLC System for Indoor Applications
This paper contemplates a relay-assisted visible light communication (VLC)
system, where the light source (Table lamp) acts as a relay node and cooperates
with the main light source. Following the IEEE 802.15.7r1 VLC reference channel
model, we assume that there are two different light sources present in an
office room. The first one is the source terminal present on the ceiling and
another one is the desk lamp that serves as the relay station which works in
full-duplex method. Because of the loop interference channel, we model VLC
relay terminal using ray tracing simulations. We have analyzed bit error rate
(BER) performance of the relay-assisted VLC system using binary phase shift
keying-subcarrier intensity modulation (BPSK-SIM) technique. The proposed
method outperforms existing phase shift keying (PSK) and square M-quadrature
amplitude modulation (M-QAM) techniques. The proposed VLC system using BPSK-SIM
technique achieves a BER performance of for an SNR of 20 dB. The results of
proposed full duplex and half duplex relayed VLC system are evaluated using
equal power allocation (EPA) and optimum power allocations (OPA) techniques
over three different modulation schemes which are 2-PSK, square M-QAM,
BPSK-SIM
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