COMPARISON OF VARIOUS NUMERICAL DIFFERENCING SCHEMES IN PREDICTING NON-NEWTONIAN TRANSITION FLOW THROUGH AN ECCENTRIC ANNULUS WITH INNER CYLINDER IN ROTATION

Flow through annulus is a widely solved problem in fluid mechanics because of its practical applicability in many areas. In oil well drilling, cuttings generated are of non-Newtonian nature which flows through an eccentric annulus with inner cylinder in rotation, considering the real drilling situations. In the present work, a comparison have been done amongst three differencing schemes, the second order upwind, the Power law scheme and QUICK scheme used in computational fluid dynamics solution algorithms, so as to find the best amongst them to solve transition flow for this case as well as in general. A three dimensional orthogonal hexahedral mesh with suitable boundary conditions & input parameters was taken as computational domain for eccentric annulus. This was solved with standard k-ω turbulence model and SIMPLE algorithm. Results were validated against the published experimental work of J. M. Nouri, et. al [1]. Radial velocity, axial velocity and tangential velocity of fluid were plotted along chosen planes and contours of molecular viscosity as well as turbulence kinetic energy were observed for comparison amongst the solutions obtained by three differencing schemes. Although in most of the cases close agreement have been observed between computational data, but as far as prediction of radial velocity is concerned there was surprising difference amongst the three schemes

Seismic wave characteristics in anisotropic attenuating media .

Seismic anisotropy in shales is a complex phenomenon. A number of theoretical shale models are investigated to study the effects of clay orientation, aspect ratio of cracks, porosity and fluid types on the synthetic seismograms.A synthetic seismogram is a tool to investigate seismic wave characteristics in anisotropic attenuating media. A numerical technique for the computation of synthetic seismograms in a homogeneous, as well as in a multilayered anisotropic medium was developed. Full waveform theory is used to compute the synthetic seismograms. The medium can be elastic or viscoelastic. In the latter case, attenuation is introduced by giving materials complex elastic constants. To ensure that there are no false arrivals in the synthetic seismogram, it is important to carefully control the integration kernel singularity points, especially those due to repeated roots of the associated Green-Christoffel equation. A novel approach is developed to safely track the continuity of the integration kernel and, hence, the polarization vectors in critical and supercritical zones.The reflectivity approach is followed to consider wave propagation in a multilayered medium. A simple and concise implementation of this method is developed. This approach also enables one to investigate frequency dependent reflection coefficients varying with incidence angle and azimuth. The modeling of reflection coefficients in fractured media suggests that amplitude versus offset and azimuth (AVOAz) can be helpful in detecting fractured reservoirs.In a new development, the effect of attenuation on P- and S-wave radiation patterns in viscoelastic anisotropic media is investigated. The understanding of radiation patterns in homogeneous media is applied to interpret various wave types in attenuating multilayered media. Both the amplitude and the frequency content of the synthetic seismograms are affected by attenuation properties of the media. The spectral decomposition technique is found to be useful in our understanding of the attenuation effects

Seborrahic keratitis: a benign pigmented skin lesion management

Seborrhoeic keratosis are formed from the basal layer of epidermal cells and contain melanocytes. Many terms such as senile wart, melanoacanthoma, basal cell papilloma, senile keratosis and seborrhoeic wart have been applied, but seborrhoeic keratosis is the most widely accepted term. In our case a 50-year-old female presented to the surgery OPD with a painless pigmented skin lesion 2.5cm lateral to the left lateral canthus and 1cm below the hairline of size of 4 *4cm. Pigmented lesion was from last 8 years and slowly progressive in nature and was not associated with any co morbid conditions. On clinical evaluation the clinical diagnosis of epidermal nevus was given and an excisional biopsy with rhomboid flap placement was performed and the tissue was sent for histopathological examination. Post operative period was uneventful and the histopathology report states the seborrhoeic keratosis. Hence, lesions for which the diagnosis is uncertain, based on the history and gross examination, should be biopsied for histopathologic examination to rule out malignancy

EMERGENCE OF METABOLIC SYNDROME IN POLICE PROFESSIONALS: A LONGITUDINAL OBSERVATIONAL STUDY

Objective: This is a longitudinal observation looking for the emergence of metabolic syndrome (MetS) in a rapid response police unit. Methods: After taking informed consent, measurements were taken of blood pressure, body mass index (BMI), waist circumference, triglycerides, HDL-cholesterol, and fasting blood glucose periodically in 2019, 2021, and 2023 in January. 146 police officers enrolled out of 148 screened and 117 completed the study. Results: In four years, the proportion of individuals with MetS values exceeding the norm increased by 20-30% for each component with 56 new cases of impaired metabolic parameters and 13 new cases of MetS observed among 110 previously unaffected police officers. Conclusion: A significant increase in the number of Metabolic Syndrome was found, particularly via its effects on blood lipid levels in police personnel which a highly stressful for professionals. Future longitudinal studies with continuous stress monitoring and comparing with a control will more in-depth knowledge into it

A safe method for the retrieval of a dislocated trial head in total hip arthroplasty

Total hip arthroplasty is a life changing procedure providing a significant improvement in the quality of life for those receiving treatment. An 81-year-old male with severe right sided hip osteoarthritis underwent uncemented total hiparthroplasty. Intraoperatively the 32mm trial head dislodged from the trial stem over the anterior rim of the acetabulum relocating to within the pelvic cavity. Time efficient retrieval was performed during primary surgery through a mini-incision at the iliac crest

Agroforestry practices for physiological amelioration of salt aff ected soils

Agroforestry is a sustainable land use system act as an alternative form of biological reclamation in salt affected soils apart from sustainable production, continuous income, and regular employment along with food and nutrition security. In general, salt affected soils get ameliorated by tree species; however, following factors such as nature and type of tree species planted, growth habit, quantity and quality of litter production, planting density, nitrogen fixation, and different management practices are influenced. In the present study, various studies pertaining to soil reclamation in the salt affected soils are reviewed. Overall result showed that trees grown with crops, horticultural crops, pastures resulted in improvement of physical and chemical properties of soil under various agroforestry systems. For instance, reduction of soil pH, electrical conductivity, and exchangeable sodium percentage minimization of salt deposition in the upper layers of the soil, improvement of water permeability and water holding capacity, improvement of infiltration rate and hydraulic conductivity with soil fertility, enhancement of cation exchange capacity, and other features are characteristics of soil as influenced by tree species, as well as through agroforestry practices. Various multipurpose tree species such as Acacia auriculiformis, Acacia nilotica, Albizia lebbeck, Terminalia arjuna, Casuarina equisetifolia, Prosopis cineraria, Prosopis juliflora; and fruit trees such as Zizyphus jujuba, Emblica officinalis, Syzygium cumini, and Tamarindus indica ameliorated the different salt affected soils in different agroforestry systems viz., agrisilvicultural system, silvipastoral system, multipurpose wood lot, and agrihorisilvicultural system. Thus, agroforestry system provides an alternative for restoring soil health and amelioration of salt affected soils for further yield improvement. Therefore, these species are suggested for reclamation of salt affected soil through agroforestry systems