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Sayanta Midya ¹, Anish Pal ¹, Anish Pal ¹, Aakash Gupta ¹, Nirmalendu Biswas ², Nirmalendu Biswas ², Nirmal K. Manna ¹, Aakash Gupta ¹, Nirmal K. Manna ¹

Affiliations
1 Department of Mechanical Engineering, Jadavpur University, Kolkata-700032, IN
2 Department of Power Engineering, Jadavpur University, Salt Lake, Kolkata-700098, IN

Abstract

The effect of corner flow is investigated in an inclined square cavity numerically. Both clear domain and porous substance are considered in the cavity. The study is conducted under distributed heating and cooling arrangement applied on the four walls. This numerical study is carried out on a ventilated cavity providing entry and exit at diagonally opposite corners. On fluid dynamics, effects of various flow parameters like Richardson number (Ri = 0.1-20), Reynolds number (Re = 10-200), cavity inclination angle (γ = 0-180°), Darcy number (Da = 10^-4-10^-7) and porosity (ε = 0.3-1.0) are analyzed systematically. Streamlines, isotherms and average Nusselt number are utilized for exploring heat transfer of the cavity.

Keywords

Mixed Convection, Inclined Cavity, Corner Flow, Heat Transfer Characteristics.

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Anish Pal ¹, Sayanta Midya ¹, Aakash Gupta ¹, Nirmalendu Biswas ², Nirmal K. Manna ¹

Affiliations
1 Department of Mechanical Engineering, Jadavpur University, Kolkata 700032, IN
2 Department of Power Engineering, Jadavpur University, Salt Lake, Kolkata–700106, IN

Abstract

The external flow based mixed convection has wide uses in many applications. The present numerical investigation is carried out on a ventilated porous cavity providing fluid flow diagonally. Two heating elements and cooling elements are placed in the middle of the walls of the cavity. The simulation is carried out using an inhouse code for a range of parameters such as different flow regime (using Richardson number Ri= 0.120), Flow velocity (using Reynolds number Re= 10200), permeability (using Darcy number Da= 10 10 ) and porosity ( = 0.30.8) of the porous media. The -7 -3 ε results are presented using isotherms, streamlines and average Nusselt number. The obtained results show a strong parametric dependence of fluid flow and associated heat transfer phenomena. An exception to the usual trends of heat transfer characteristics of clear and porous domain, the heat transfer of porous domain increases due to corner flow.

Keywords

Mixed Convection, Porous Cavity, Corner flow, Heat Transfer.

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Preeti Bajaj ¹, Aakash Gupta ²

Affiliations
1 Professor and Head, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN
2 Former PG Resident, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN

Abstract

Introduction: Thalassemia and other hemoglobinopathies are the most common routinely encountered congenital anemias in India. Sickle cell anemia is very common, so a study to rule out all the hemoglobinopathies is essential. Aims and Objectives: The present study was conducted to diagnose various hemoglobinopathies among clinically suspected cases., the present study was conducted to diagnose various hemoglobinopathies among clinically suspected cases. Materials and Methods: A total of 212 cases cases were undertaken in this study after they met the inclusion and exclusion criteria. HPLC was performed on the samples received in the Central Clinical Laboratory of Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik, Maharashtra. Results: Out of 212 cases, 42 cases showed positivity for thalassemia or presence of abnormal hemoglobin, with 8% cases of Beta thalassemia trait, 1.88% cases of Beta thalassemia major, 4.7% cases of Sickle cell trait, 4.24% cases of Sickle cell disease and 0.94% cases of Sickle-thalassemia. Conclusions: HPLC is a fast, reliable, and cost-effective method to diagnose any suspected case of hemoglobinopathy.

Keywords

HPLC, Thalassemia, Hemoglobinopathies

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Devangana Rajyaguru ¹, Preeti Bajaj ², Gayatri Soneta ³, Aakash Gupta ⁴

Affiliations
1 Associate Professor, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN
2 Professor and Head, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN
3 PG Resident, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN
4 Former PG Resident, Department of Pathology, Dr. Vasantrao Pawar Medical College, Hospital and Research Centre, Nashik – 422003, Maharashtra, IN

Abstract

Introduction: Severe COVID-19 can lead to critical illness, with Acute Respiratory Distress (ARDS) and Multi-organ Failure (MOF) as its primary complications, eventually followed by intravascular coagulopathy. Haematological changes are common in patients with COVID-19, which include reduced lymphocyte count and platelet count but normal white blood cell count and prolonged activated partial thromboplastin time. Using a simple test like platelet count for assessing the risk of mortality and early identification of severe cases will help in preventing the life threatening complications in patients of COVID-19. Aims and Objectives: To study trends of thrombocytopenia in patients of COVID-19 and to study the correlation between thrombocytopenia and severity of cases of COVID-19. Materials and Methods: The study was carried out in Central Clinical Laboratory in a tertiary care centre. A total of 138 random subjects who were admitted in the COVID ICU were included after they satisfied the eligibility criteria. The CBCs were analyzed on the Beckmann Coulter automated cell count analyzer with EDTA samples obtained from peripheral venipuncture of the patients. Platelet trends over the three samples were studied. Results: An average of all three platelets counts for the patients revealed an overall decreasing trend in cases of non survivors, whereas an overall upward trend was noted in the survivors. A total of 79 patients showed thrombocytopenia (platelet count less than 1.5 lakhs/mm3 ), during at least one of the tests.46 (33.33%) of these patients succumbed, whereas 33 (23.9%) patients survived. Decreasing trends or overall decreasing trends (Increasing then decreasing) were observed in larger number of non survivors as compared to survivors. Also increasing or overall increasing trends (decreasing then increasing) were common in the survivors. Discussion: Hematological changes are common in SARS patients. For thrombocytopenia, the possible mechanisms of SARS-CoV associated thrombocytopenia may include, 1. Direct infection of megakaryocytes and platelets potentially, inducing cell apoptosis and growth inhibition and/or 2. Immune damage of megakaryocyte progenitor cells or platelets; In addition, the lung damage in SARS patients may also play a role in inducing thrombocytopenia. Conclusion: In this study, we found that platelet count may be a simple, economic, rapid and commonly available laboratory parameter that could straightforwardly discriminate between COVID patients with and without severe disease, while the study of serial platelets counts as trends could help identifying those with a serious risk of mortality.

Keywords

COVID-19, Platelet Trends, Prognostic Marker, Thrombocytopenia

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