368 research outputs found
Interactional aerodynamics and acoustics of a propeller-augmented compound coaxial helicopter
The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model. This has been done to investigate the ability of models of this type to capture the aerodynamic interactions that are generated between the various components of realistic, complex helicopter configurations. Simulations reveal the aerodynamic environment of the coaxial main rotor of the configuration to be dominated by internal interactions that lead to high vibration and noise. The wake of the main rotor is predicted to interact strongly with the tailplane, particularly at low forward speed, to produce a strong nose-up pitching moment that must be countered by significant longitudinal cyclic input to the main rotor. The wake from the main rotor is ingested directly into the tail propulsor over a broad range of forward speeds, where it produces significant vibratory excitation of the system as well as broadband noise. The numerical calculations also suggest the possibility that poor scheduling of the partition of the propulsive force between the main rotor and propulsor as a function of forward speed may yield a situation where the propulsor produces little thrust but high vibration as a result of this interaction. Although many of the predicted effects might be ameliorated or eliminated entirely by more careful or considered design, the model captures many of the aerodynamic interactions, and the resultant effects on the loading on the system, that might be expected to characterise the dynamics of such a vehicle. It is suggested that the use of such numerical techniques might eventually allow the various aeromechanical problems that often beset new designs to be circumvented - hopefully well before they manifest on the prototype or production aircraft
Impact of Public Programs on Fertility and Gender Specific Investment in Human Capital of Children in Rural India: CrossSectional and Time Series Analyses
Constraints Faced by Stakeholders under Agriculture Technology Management Agency (ATMA)
Agriculture Technology Management Agency (ATMA) is a registered society in India with key stakeholders enmeshed with various agricultural activities for sustainable agricultural development in the state, with focus at district level. It is a hotbed for integrating research, extension and marketing activities and decentralizing day-to-day management of the public Agricultural Technology Development and Dissemination System. The present study was carried out in Andhra Pradesh state to explore the constraints faced by the extension functionaries at each level of decentralized management. Moreover, constraints perceived by the farmers with the support of ATMA in realizing their needs were also studied
Like-sign dimuon charge asymmetry in Randall-Sundurm model
We confirm that in order to account for the recent D\O\ result of large
like-sign dimuon charge asymmetry, a considerable large new physics effect in
is required in addition to a large CP violating phase in mixing. In the Randall-Sundrum model of warped geometry, where the
fermion fields reside in the bulk, new sources of flavor and CP violation are
obtained. We analyze the like-sign dimuon asymmetry in this class of model, as
an example of the desired new physics. We show that the wrong charge asymmetry,
, which is related to the dimuon asymmetry, is significantly altered
compared to the Standard Model value. However, experimental limits from , as well as mixing and electroweak corrections
constrain it to be greater than a away from its experimental average
value. This model cannot fully account for the D\O\ anomaly due to its
inability to generate sufficient new contribution to the width difference
, even though the model can generate large contribution to the
mass difference .Comment: 20 pages, 9 figures, discussions and references added, accepted for
publication in Physical Review
IN SILICO STUDIES OF THE SECONDARY METABOLITES OF SOLANUM TORVUM SW. FOR THEIR ANTIASTHMATIC ACTIVITY
Objective: Solanum torvum Sw., Family: Solanaceae, commonly known as Turkey Berry is used by the traditional tribes for the treatment of cold, cough, tuberculosis, hepatotoxicity, cancer, etc. The action of the plant towards the treatment of these diseases has been proven except for asthma. The present study is to prove the antiasthmatic activity of methanolic extract and the secondary metabolites of Solanum torvum Sw using in silico docking studies in compare to reference standard Dexamethasone, a synthetic cortisone derivative.Methods: The GC-MS analysis of the dried methanolic extract of the dried fruits of Solanum torvum Sw. and the total saponin fraction has been carried out to know the important moieties that are responsible for the antiasthmatic activity.Results: The results from the docking studies showed that the compounds Cholesta-5,7,9-(11)-trien-3-ol,4,4-dimethyl, (3á); Lanosta-7,9-(11),20-triene-3α, 18-diol, diacetate and Cholestan-26-oic acid,3,7,12,24-tetrakis (acetyloxy), methyl ester, (3à ,5á,7à ,12à ) were found to have significant scores of-6.8,-6.9 and-6.9 respectively towards Glucocorticoid receptor protein (Gr), (PDB id: 4UDC) which is very similar to the affinity of the standard (-7.1). These compounds passed the drug-likeness test. A modification in the structure can be brought, which makes the compounds more potent. The compounds 9, 12-Octadecadienoic acid, ethyl ester; Hexadecanoic acid, ethyl ester; 9-Octadecenoic acid (Z), methyl ester; Oxacycloheptadec-8-en-2-one, (8Z) have passed the Blood Brain Barrier (BBB) filter of the drug-likeness test.Conclusion: The antiasthmatic activity of the drug may be due to the similarity with the structure of Dexamethasone. Further research can be carried out in order to improve the clinical significance of these extracts and its metabolites
Recommendations for Future Efforts in RANS Modeling and Simulation
The roadmap laid out in the CFD Vision 2030 document suggests that a decision to move away from RANS research needs to be made in the current timeframe (around 2020). This paper outlines industry requirements for improved predictions of turbulent flows and the cost-barrier that is often associated with reliance on scale resolving methods. Capabilities of RANS model accuracy for simple and complex flow flow fields are assessed, and modeling practices that degrade predictive accuracy are identified. Suggested research topics are identified that have the potential to improve the applicability and accuracy of RANS models. We conclude that it is important that some part of a balanced turbulence modeling research portfolio should include RANS efforts
Laparoscopic management of ileal endometriosis: presented as sub-acute intestinal obstruction
Patients with bowel endometriosis will usually experience a long delay in getting diagnosed as the physician will always think of other medical conditions related to bowel before considering the possibility of endometriosis. Imaging studies are not sensitive enough for definite diagnosis. Bowel endometriosis can be treated by either hormone therapy or surgical therapy. Surgery should be considered in selected patients, who have severe stenosis of intestinal lumen resulting in obstruction. Small bowel endometriosis may not be accompanied by pelvic endometriosis. When the disease involves the jejunum or the ileum, it usually has a benign course, but in rare circumstances may present as an acute abdomen. Ileal endometriosis should be carefully considered in the differential diagnosis of Crohn’s disease, because bowel endometriosis frequently produces local inflammation, adhesions, stricture and angulation. A segmental bowel resection may be required to completely treat their disease. The role of postoperative administration of gonadotropin releasing hormone analogues (GnRH) to prevent disease recurrence or increase symptom free interval is not well established
Status, Emerging Ideas and Future Directions of Turbulence Modeling Research in Aeronautics
In July 2017, a three-day Turbulence Modeling Symposium sponsored by the University of Michigan and NASA was held in Ann Arbor, Michigan. This meeting brought together nearly 90 experts from academia, government and industry, with good international participation, to discuss the state of the art in turbulence modeling, emerging ideas, and to wrestle with questions surrounding its future. Emphasis was placed on turbulence modeling in a predictive context in complex problems, rather than on turbulence theory or descriptive modeling. This report summarizes many of the questions, discussions, and conclusions from the symposium, and suggests immediate next steps
Trend analysis and variability of satellite-based soil moisture data for the Lower Bhavani basin, Tamil Nadu using Google Earth Engine
Soil moisture is a significant hydrological component that is dynamic in nature. The variation in soil moisture in the basin scale would affect the vegetation, ecology and environment. Soil moisture trend analysis aids in providing the variation of soil moisture over the basin. The present study aimed to analyse the soil moisture trend in Lower Bhavani basin, Tamil Nadu from 2003-2022. Satellite-based soil moisture Global Land Data Assimilation System (GLDAS) data was extracted from the Google Earth Engine (GEE) platform to analyse the variation and trend over the period of time. The highest and lowest soil moisture was observed during monsoon and summer months and its percentage variation was studied. Using Man-Kendall test and Sen’s slope, trend analysis was calculated for two decades (2003-2012 and 2013-2022). In 2003-2012, an increasing trend of soil moisture was observed during winter (October to February); from 2013-2022, an increasing trend was observed during both winter (October to February) and monsoon seasons (June to September). The remaining season did not follow any trend, and there was no decreasing trend in soil moisture. The trend analysis of the study will help to monitor and manage the environmental system across the Lower Bhavani basin
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