2,146 research outputs found
CFD investigation of the cold hydrodynamics of a laboratory scale CFB furnace
This investigation presents a computational and experimental study of the flow characteristics of a laboratory scale CFB cold model riser. i) The first part of the work deals with 2D, CFD validation of a literature based CFB riser of circular cross section of 1m height. Simulation results showed good agreement with experimental literature data for radial profiles of volume fraction and particle velocity. ii) The second part is a work on simulation and experimental verification of a CFB riser flow characteristics of a CFB riser of rectangular cross section (400mm x 550mm x2000mm). An experimental run on the test rig was conducted for sand of 300 micron size at a fluidization velocity of 4 m/s and the fluidization behavior was captured on a high speed camera. For simulation, 3D, transient, Euler-ian approach combined with the Kinetic theory of Granular flow and Gidaspow drag model was used to describe the gas–particle behavior. A frame by frame visual comparison of instantaneous volume fraction distribution was made between camera images and 3D simulated profiles. A further graphical comparison between experimental literature data and simulated 3D profiles of volume fraction and particle velocity profiles yielded fairly good results. It was observed that, in spite of non inclusion of turbulence factor in the current 3D simulation, no significant influence was observed in the result
Observational study of tympanic membrane changes in allergic rhinitis
Background: Allergic rhinitis (AR) is a common condition affecting 20-30% of the population. This condition affects not only the nose but also the sinuses and ears in many ways. Many studies are there worldwide implicating AR as a cause of serous otitis media. But only few studies have actually studied the tympanic membrane (TM) changes observed in patients with allergic rhinitis. The aim of this study is to document the TM changes observed in patients with AR and to correlate them with the duration of symptoms and also influence of prior treatment of AR on the TM changes observed.Methods: A total of 111 patients and so 222 ears were studied. A detailed history of the duration of symptoms and any prior treatment for AR was recorded. The TM changes seen were classified and recorded. The duration of disease and treatment were taken as grouping variables and the tympanic membrane changes were ranked and used as testing variable. The results were statistically analyzed using non- parametric test, Kruskal – Wallis test.Results: There was no statistically significant correlation between duration of AR and the TM changes observed. However there was a significantly less number of patients with TM retraction observed in the patients who had taken prior treatment compared to those patients who had taken no prior treatment.Conclusions: It is concluded that institution of early treatment may prevent development of Eustachian tube dysfunction and TM changes in patients with AR
Light Curves of Rapidly Rotating Neutron Stars
We consider the effect of rapid rotation on the light curves of neutron stars
with hot polar caps. For ms spin periods, the pulse fractions can
be as much as an order of magnitude larger than with simple slowly-rotating
(Schwarzschild) estimates. Doppler boosting, in particular, leads to
characteristic distortion and ``soft lags'' in the pulse profiles, which are
easily measurable in light curves with moderate energy resolution. With photons it should also be possible to isolate the more subtle distortions
of light travel time variations and frame dragging. Detailed analysis of high
quality millisecond pulsar data from upcoming X-ray missions must include these
effects
Comparison between paracervical and intracervical block before procedures on uterine cavity and cervical dilatation
Background: Procedures like dilatation and curettage and manual vacuum aspirations are one of the commonest procedures conducted in the outpatient Department of Obstetrics and Gynecology. Objective of present study was to find out whether intracervical block is as effective as paracervical block in patients undergoing cervical dilatation and procedures on uterine cavity.Methods: Patients undergoing dilatation and curettage or manual vacuum aspiration were given either paracevrical block or intracervical block. The pain during cervical dilatation and curettage or manual vacuum aspiration were assessed on a 10 cm visual analogue scale.Results: Mean visual analogue score during dilatation was comparable in both groups. Mean visual analogue score were comparable during dilatation in both groups before curettage or manual vacuum aspiration. Mean visual analogue scores during manual vacuum aspiration or curettage was also comparable with both groups. One patient had a serious side effect of convulsion during paracervical block.Conclusions: Intracervical block is preferable to paracervical block during procedures like cervical dilatation and on procedures on uterine cavity as intracervical block requires less technical precision than paracervical block
EXPERIMENTAL AND MATHEMATICAL INVESTIGATION ON PERFORMANCE AND EMISSION CHARACTERISTICS OF OXYGEN ENRICHED AIR IN INTAKE OF A SINGLE CYLINDER DIESEL ENGINE
This research revealed that the single cylinder diesel engine performance and emission  characteristics are improved by the oxygen content enriched intake air and was varied between 21% to 27 % (ie., 21,23,25,27% by the volume). The effects of enriched oxygen with different loads are analyzed in terms of brake thermal efficiency, specific fuel consumption, and also the environmental pollutant like NOx, CO, HC and Smoke. The  mathematical experiment were designed using a statistical tool know as design expert based on response surface modeling. Using RSM to predict the response parameter like brake thermal efficiency, brake specific fuel consumption, carbon monoxide, hydrocarbon, nitrogen oxides and smoke. Optimization of the input and response parameters is also done using desirability approach. Finally a software tool is developed using LabVIEW software for predicting engine parameters when the engine input parameters are given
Role of neutron transfer in the reaction mechanism of Be+Tm, Ta, Re and Au systems
The contribution of one neutron stripping cross section to the total reaction
cross section has been studied for Be projectile incident on Tm,
Ta, Re and Au targets around Coulomb barrier energy.
The measured one neutron stripping cross sections for these systems have been
compared with the coupled channel calculations. The recently developed global
set of optical model potential parameters for Be projectile has been used
in the present calculations. The cumulative of measured complete fusion (CF),
incomplete fusion (ICF), one neutron stripping and calculated non-capture
breakup (NCBU) cross sections is found to explain almost the reaction cross
sections for all the targets. A very small contribution from target inelastic
states and elastic breakup may contribute to the remaining part. The percentage
fraction of cross section for CF, ICF, one neutron stripping, and NCBU over
reaction cross section show the dominance of neutron transfer and NCBU at below
barrier energies while CF and ICF processes have the major contribution at
above barrier energies.Comment: 12 pages, 3 figure
Synthesis and interaction of thiazolo [2, 3-a] isoquinoline analog with DNA
569-573A reaction between 1-(furan-2-yl)-3,4-dihydroisoquinoline and thioglycolic acid using N,N-Dicyclohexylcarbodiimide at 0−5 °C has given 10b-(furan-2-yl)-5,6-dihydro-2H-thiazolo[2,3-a]isoquinolin-3(10bH)-one [FUIQTGA]. The interaction between FUIQTGA and DNA has been studied using UV-visible spectroscopy, fluorescence and circular dichroism techniques. Static quenching mechanism is observed from fluorescence measurements of interaction between FUIQTGA and DNA. Circular dichroism reveals the minor groove binding mode between FUIQTGA and DNA
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