Browsing by Author "Sujeet Kumar Shukla"

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Coexisting cranial and multiple spinal meningioma in a child-report of a case
(2011) Sujeet Kumar Shukla; Adarsh Trivedi; Vivek Sharma; Kulwant Singh
Von Ricklinghausen's disease is commonly associated with simultaneous cranial and spinal meningioma but these are not true meningiomas. Craniospinal meningiomas without Von Ricklinghausen's disease are very rare. We report a 13-year-old girl who presented with two episodes of right focal seizure with secondary generalisation of three year's duration, weakness of both lower limbs for 6 months, and retention of urine of three month's duration. MRI brain showed enhancing lesion in the left fronto-parietal region. MRI spine revealed enhancing intradural extramedullary lesion at D4-5, D9-10, and L1-2. The tumours were excised completely in a single stage, first by craniotomy then by multi level laminectomy. On histology the spinal meningioma had predominant meningothiliomatous. We followed up for 6 months and the patient recovered with power grade 4/5 both lower limb. © 2010 Springer Science+Business Media, LLC.
Evaluation of numerical schemes for dispersed phase modeling of cyclone separators
(Hong Kong Polytechnic University, 2011) Sujeet Kumar Shukla; Prashant Shukla; Pradyumna Ghosh
This study investigates the performance of different discretization schemes for simulation of dispersed phase of cyclone separators by using Reynolds stress turbulence model facility of CFD code Fluent 6.3.26. The continuous flow inside the cyclone separator is simulated by solving Reynolds averaged three dimensional unsteady Navier-Stokes equation in Eulerian reference frame whereas the dispersed phase is modeled using Lagrangian approach. Analysis of computed results shows that the high order discretization schemes give satisfactory performance for simulation of dispersed particles of all size. However the prediction of trapezoidal discretization scheme is found to be marginally better than that of the Runge-Kutta scheme. The low order schemes and combination of low order and high order schemes failed to predict accurately the collection efficiency of the smaller dispersed particles. The results suggest that the CFD method using trapezoidal scheme for discretization of equation of motion of dispersed particles is the optimum choice for simulation of the second phase of cyclone separators.
Evaluation of numerical schemes using different simulation methods for the continuous phase modeling of cyclone separators
(2011) Sujeet Kumar Shukla; Prashant Shukla; Pradyumna Ghosh
The steady and unsteady state simulations of Stairmand cyclone separator were carried out to investigate the performance of different interpolation schemes for discretization of pressure gradient and advection terms. The RSM turbulence model was revisited to explore its simulation capability of PVC phenomenon and fluctuating velocity profiles of cyclone separators. The combination of Presto, SO, standard and BFW schemes for discretization of pressure gradient and FOU, power law, SOU, QUICK and MUSCL schemes for discretization of advection terms were studied. The double precision solver of Fluent 6.3.26 and modified RSM turbulence model constants of Jiao et al. (Chem. Eng. Technol. 30 (2007) 15-20) were also verified for simulation of cyclone separators. The predicted mean and fluctuating velocity profiles and pressure drop inside the cyclone separator with steady and unsteady simulations have been compared to experimental results available in literature. The steady state simulation failed to predict velocity profiles and pressure drop inside cyclone separator accurately, whereas the unsteady state simulation predicted velocity profiles, pressure drop and PVC phenomenon close to experimental values. The prediction of fluctuating velocity profile was better than previously reported work in the core region compared to the off core region. The present study revealed that the SOU scheme for discretization of advection terms of momentum, kinetic energy and its dissipation rate equations and the FOU scheme for Reynolds stresses together with the Presto scheme for discretization of pressure gradient with unsteady simulation are the optimum choice for simulation of cyclone separators. © 2011 The Society of Powder Technology Japan.
Primary lumbosacral intradural hydatid cyst in a child
(2010) Sujeet Kumar Shukla; Vivek Sharma; Kulwant Singh; Adarsh Trivedi
Primary spinal hydatid cyst is very rare lesion affecting less than 1% of the total cases of the hydatid disease. In this study, we report a case of spinal hydatid in a 5-year old boy presented with a history of backache, leg pain, difficulty in walking, and bowel and bladder incontinence for 4 months. An intradural nonenhancing cystic lesion was detected using magnetic resonance imaging from L4 to sacral region, and histopathological findings were suggestive of hydatid cyst.