Numerical Investigation on Gas Bubbling Assisted Inclusion Transport and Removal in Multistrand Tundish

Vipul Kumar Gupta,Pradeep Kumar Jha,Pramod Kumar Jain 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

In continuous casting, the molten metal quality in the mold is affected by flow pattern, temperature distribution and inclusiontransport in the multistrand tundish. Natural convection due to thermal buoyancy directly influences these parameters andwith gas bubbling, further improvisation can be made. In the present work, numerical investigation of the effect of thermalbuoyancy is carried out to examine the flow field, temperature distribution and inclusion trajectories. Further, gas bubblingcurtain modeling using the Euler-Euler approach is performed for the different locations on the bottom wall of the tundishand quantitative analysis of tundish performance is presented using residence time distribution (RTD) curves. The resultsshow that big circulation loop generated due to thermal buoyancy assists in inclusion removal and mixing at each outlet. Gas bubbling increases the molten metal flow velocity in the central region of tundish, leading to a decrease in the dimensionlessnumber Gr/Re2 near the outlets which are far away from the inlet of the tundish i.e. outlet 2 and outlet 3. Hence, thedominance of natural convection decreases. The inclusion removal rate is found to increase significantly as the circulationloop formed at each side of the curtain forces them upward direction. However, the reported inclusion removal rate in gasbubbling cases is found to be independent of particle size and curtain location.

Root guided implants - a novel approach for the precision placement of immediate implants: A case series

Pramod Kumar(Pramod Kumar ),Prasanth T(Prasanth T ),Satisha TS(Satisha TS ),Nitin Gupta(Nitin Gupta ),Sumita Manandhar(Sumita Manandhar ) 대한치과이식임플란트학회 2022 The Korean Academy of Implant Dentistry Vol.41 No.3

Immediate implant placement is the current modality to provide implant placement following tooth extraction. Immediate implants in posterior multirooted teeth pose challenges in terms of proper angulation and parallelism. Engaging the inter-radicular septal bone provides the advantage of primary stability. Osteotomy site preparation through the septal bone with roots of the natural teeth as a guide provides a precise osteotomy procedure with minimal collateral damage to the adjacent area. This case series aimed to assess the success of immediate implant placement in posterior multirooted teeth using the residual roots as anatomical guides. Three cases of grossly decayed posterior teeth were treated with immediate implant placement. The osteotomy site was prepared using the roots as surgical guides. Implant stability was assessed by resonance frequency analysis (RFA) immediately after placement and 6 months post-op. Healing was uneventful in all cases. Optimal implant stability quotient (ISQ) values of above 70 were achieved, which are suggestive of good primary stability. The desired angulation and parallelism were obtained by utilizing the residual roots as anatomical guides. Six months post-surgically, the patient presented with healthy peri-implant tissue and successful osseointegration. Root-guided implant placement is a novel technique wherein residual roots provide a surgical guide for the placement of immediate implants in multirooted posterior teeth.

Performance evaluation of safety-critical systems of nuclear power plant systems

Kumar, Pramod,Singh, Lalit Kumar,Kumar, Chiranjeev Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.3

The complexity of safety critical systems of Nuclear Power Plant continues to increase rapidly due its transition from analog to digital systems. It has thus become progressively more imperative to model these systems prior to their implementation in order to meet the high performance, safety and reliability requirements. Timed Petri Nets (TPNs) have been widely used to model such systems for non-functional analysis. The paper presents a novel methodology for the analysis of the performance metrics using PN modeling. The paper uses the isomorphism property of the TPNs and the Markov chains for the performance analysis of the safety critical systems. The presented methodology has been validated on a Shutdown System of a Nuclear Power Plant.

Squamous Cell Carcinoma in Exstrophy of the Bladder

Pramod Kumar Sharma,Praveen Kumar Pandey,Mukesh Kumar Vijay,Malay Kumar Bera,Jitendra Pratap Singh,Kaushik Saha 대한비뇨의학회 2013 Investigative and Clinical Urology Vol.54 No.8

Exstrophy of the bladder is a rare congenital anomaly with an incidence of about 1 per 50,000 newborns. The malignant potential of the exstrophied bladder mucosa is well known; 95% are adenocarcinomas, and 3% to 5% are squamous cell carcinomas. Most of the malignant tumors (60%) associated with an exstrophy of the bladder occur during the fourth and fifth decades of life. Of the remaining, about 20% each occur after 60 years and before 40 years. Here we present a case in which squamous cell carcinoma developed in an unrepaired exstrophy of the bladder. We present the management of the case and a brief review of the literature.

Characterization of Cellulose Fiber Extracted from Stems of Myriostachya wightiana (MW) Plants: A Viable Reinforcement for Polymer Composite

Pramod Kumar Parida,Arun Kumar Pradhan,Mihir Kumar Pandit 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2

There is an urgent need to investigate more eco-friendly fibres due to the high cost of traditional cellulosic fibres. Eco-friendlyMW fibre was extracted and characterised as a potential replacement for risky artificial fibre. Physicochemical, XRD, FTIR,SEM, thermal analysis, and Weibull distribution methods were used to study MW fibre as a biocomposite reinforcement. The density, tensile strength, Young's modulus, strain at failure, and micro-fibril angle of MW fibre with an average diameterof 102.278 μm were found to be 1372–1510 kg/m3, 46.554 MPa, 2.442 GPa, 8–9%, and 22 ± 1°, respectively. The predictedYoung's modulus and strength of the fibre showed a good match with the experimental data in the Weibull distributionanalysis. In addition, FTIR verified the presence of cellulose (O = H), hemicellulose (C = O), lignin (C = C), and wax (CC)in the fibre. XRD study reveals CI and CS of 58.07% and 2.86 nm, respectively. The activation energy of 63.156 kJ/mol andthermal stability up to 300 °C were noted during TGA, DTGA, and DSC studies. The fiber's high cellulose content (70 wt%)and roughness (23.664 μ m) contributed to its specific strength and adherence to the polymer matrix. The importance of thepresent study suggests potential applications of this fiber in the fields of papermaking, packaging, lignocellulose composites,and cellulose nanocomposite manufacturing.

Coenzyme Q10: a progress towards the treatment of neurodegenerative disease

Peeyush kumar,Pramod kumar,Alpana ram,Mithilesh kumar,Rajeev kumar 경희대학교 융합한의과학연구소 2010 Oriental Pharmacy and Experimental Medicine Vol.10 No.4

Coenzyme Q10 (CoQ10, or ubiquinone) is an electron carrier of the mitochondrial respiratory chain (electron transport chain) with antioxidant properties. In view of the involvement of CoQ10 in oxidative phosphorylation and cellular antioxidant protection a deficiency in this quinone would be expected to contribute to disease pathophysiology by causing a failure in energy metabolism and antioxidant status. Indeed, a deficit in CoQ10 status has been determined in a number of neuromuscular and neurodegenerative disorders. Primary disorders of CoQ10 biosynthesis are potentially treatable conditions and therefore a high degree of clinical awareness about this condition is essential. A secondary loss of CoQ10 status following HMG-CoA reductase inhibitor (statins) treatment has been implicated in the pathophysiology of the myotoxicity associated with this pharmacotherapy. CoQ10 and its analogue, idebenone, have been widely used in the treatment of neurodegenerative and neuromuscular disorders. These compounds could potentially play a role in the treatment of mitochondrial disorders, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, Friedreich’s ataxia, and other conditions which have been linked to mitochondrial dysfunction. This article reviews the physiological roles of CoQ10, as well as the rationale and the role in clinical practice of CoQ10 supplementation in different neurological diseases, from primary CoQ10 deficiency to neurodegenerative disorders. These will help in future for treatment of patients suffering from neurodegenerative disease.

Reconfigurable FIR Filter for Dynamic Variation of Filter Order and Filter Coefficients

Pramod Kumar Meher,Sang Yoon Park 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.3

Reconfigurable finite impulse response (FIR) filters whose filter coefficients and filter order change dynamically during run-time play an important role in the software defined radio (SDR) systems, multi-channel filters, and digital up/down converters. However, there are not many reports on such reconfigurable designs which can support dynamic variation of filter order and filter coefficients. The purpose of this paper is to provide an architectural solution for the FIR filters to support run-time variation of the filter order and filter coefficients. First, two straightforward designs, namely, (i) single-MAC based design and (ii) full-parallel design are presented. For large variation of the filter order, two designs based on (iii) folded structure and (iv) fast FIR algorithm are presented. Finally, we propose (v) high throughput design which provides significant advantage in terms of hardware and/or time complexities over the other designs. We compare complexities of all the five structures, and provide the synthesis results for verification.

Study of minerals and selected environmentally sensitive elements in Kapurdi lignites of Barmer Basin, Rajasthan, western India: implications to environment

Pramod K. Rajak,Vijay K. Singh,Asha L. Singh,Narendra Kumar,Om P. Kumar,Vishvajeet Singh,Aniruddha Kumar,Rai Ankita,Shweta Rai,Amiya S. Naik,Prakash K. Singh 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.4

The present study is an attempt to know the temporal and spatial distribution of geochemical components in the lignite deposit of Kapurdi, Barmer Basin (Rajasthan). Lignite samples have been subjected to proximate, ultimate and elemental analyses, and determination of mineral carbon (MINC%). Besides, various minerals and functional groups have been analyzed through X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR). Selected environmentally sensitive and potential hazardous elements like Cu, Cd, Zn, Ni, Cr, Pb, Mn, Al, Fe and Co are determined using atomic absorption spectrophotometer (AAS). To know the association of minerals with organic matter, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) has also been carried out. The concentration of Co, Ni, Cd, Pb, Na, and K is high when compared with world average and is main concern for the environmental and health hazards. The elements like Fe, Ca, Mg, Zn, and Pb have shown increasing trend from top to bottom of the lignite seam with some fluctuations in the values in few bands whereas others do not follow a definite trend of variation along the seam profile.

Cyclic codes from the first class two-prime Whiteman's generalized cyclotomic sequence with order 6

Pramod Kumar Kewat,Priti Kumari 대한수학회 2019 대한수학회보 Vol.56 No.2

Let $p_1$ and $p_2$ be two distinct odd primes with $\mathrm{gcd}(p_1-1,p_2-1)=6$. In this paper, we compute the linear complexity of the first class two-prime Whiteman's generalized cyclotomic sequence (WGCS-I) of order $d=6$. Our results show that their linear complexity is quite good. So, the sequence can be used in many domains such as cryptography and coding theory. This article enrich a method to construct several classes of cyclic codes over $\mathrm{GF}(q)$ with length $n=p_1p_2$ using the two-prime WGCS-I of order 6. We also obtain the lower bounds on the minimum distance of these cyclic codes.

A Subthreshold Swing Model for Symmetric Double-Gate (DG) MOSFETs with Vertical Gaussian Doping

Pramod Kumar Tiwari,S. Jit 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.2

An analytical subthreshold swing model is presented for symmetric double-gate (DG) MOSFETs with Gaussian doping profile in vertical direction. The model is based on the effective conduction path effect (ECPE) concept of uniformly doped symmetric DG MOSFETs. The effect of channel doping on the subthreshold swing characteristics for non-uniformly doped device has been investigated. The model also includes the effect of various device parameters on the subthreshold swing characteristics of DG MOSFETs. The proposed model has been validated by comparing the analytical results with numerical simulation data obtained by using the commercially available ATLAS™ device simulator. The model is believed to provide a better physical insight and understanding of DG MOSFET devices operating in the subthreshold regime.