• Title/Summary/Keyword: Mallik

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Onshore and Offshore Gas Hydrate Production Tests (육상 및 해상 가스하이드레이트 생산시험에 대한 고찰)

  • Lee, Sung-Rock;Kim, Se-Joon
    • Economic and Environmental Geology
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    • v.47 no.3
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    • pp.275-289
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    • 2014
  • Recent scaled-up onshore and offshore field production tests revealed that the expectancy to produce gas from the gas hydrate deposits is gradually increasing, recognizing its potentials as one of the future energy resources. The total produced gas was approximately $480m^3$ by the hot water circulation method for 6 days' operation in Mallik 2002 project in Canada. In Mallik 2006-2008 project, the gas was successfully produced stably by the depressurization method for 6 days, up to $13,000m^3$ cumulatively. The depressurization method applied in the Mallik test was revealed as an effective way to produce gas from gas hydrates. The Alaska North Slope field trial in 2012 to inject mixed gas of $CO_2$ and $N_2$ to exchange $CH_4$ was successfully completed for the first time to produce maximum $1,270m^3$ per day. The remarkable achievement is that Japan has completed first offshore production test in the Eastern Nankai Trough, and produced approximately $120,000m^3$ of methane by the depressurization method for 6 days in March 2013. The technical challenges and uncertainties obtained from Nankai Trough production test give Korea more considerations in the aspects of well completion, reservoir formation and seafloor stability, sand control, flow assurance, and etc., due to the different geological environments and geomechnical properties in Ulleung Basin in Korea.

LARGE EDDY SIMULATION OF TURBULENT CHANNEL FLOW USING ALGEBRAIC WALL MODEL

  • MALLIK, MUHAMMAD SAIFUL ISLAM;UDDIN, MD. ASHRAF
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.20 no.1
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    • pp.37-50
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    • 2016
  • A large eddy simulation (LES) of a turbulent channel flow is performed by using the third order low-storage Runge-Kutta method in time and second order finite difference formulation in space with staggered grid at a Reynolds number, $Re_{\tau}=590$ based on the channel half width, ${\delta}$ and wall shear velocity, $u_{\tau}$. To reduce the calculation cost of LES, algebraic wall model (AWM) is applied to approximate the near-wall region. The computation is performed in a domain of $2{\pi}{\delta}{\times}2{\delta}{\times}{\pi}{\delta}$ with $32{\times}20{\times}32$ grid points. Standard Smagorinsky model is used for subgrid-scale (SGS) modeling. Essential turbulence statistics of the flow field are computed and compared with Direct Numerical Simulation (DNS) data and LES data using no wall model. Agreements as well as discrepancies are discussed. The flow structures in the computed flow field have also been discussed and compared with LES data using no wall model.

Printing Morphology and Rheological Characteristics of Lead-Free Sn-3Ag-0.5Cu (SAC) Solder Pastes

  • Sharma, Ashutosh;Mallik, Sabuj;Ekere, Nduka N.;Jung, Jae-Pil
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.4
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    • pp.83-89
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    • 2014
  • Solder paste plays a crucial role as the widely used joining material in surface mount technology (SMT). The understanding of its behaviour and properties is essential to ensure the proper functioning of the electronic assemblies. The composition of the solder paste is known to be directly related to its rheological behaviour. This paper provides a brief overview of the solder paste behaviour of four different solder paste formulations, stencil printing processes, and techniques to characterize solder paste behaviour adequately. The solder pastes are based on the Sn-3.0Ag-0.5Cu alloy, are different in their particle size, metal content and flux system. The solder pastes are characterized in terms of solder particle size and shape as well as the rheological characterizations such as oscillatory sweep tests, viscosity, and creep recovery behaviour of pastes.

A Case of Post Kala-Azar Dermal Leishmaniasis in India

  • Tripathy, Kalpalata;Misra, Aparijita;Mallik, Rabinarayn;Misra, Debiprasad;Rout, Niranjan;Rath, Jayshree
    • Parasites, Hosts and Diseases
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    • v.48 no.3
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    • pp.245-246
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    • 2010
  • Post kala-azar dermal leishmaniasis (PKDL) is a rare disease. This is a solitary case report from Orissa, India. We describe a case of PKDL in a 55-year-old male who presented with multiple nodular lesions over face, trunk, and extremities. The patient had been to an endemic area of kala-azar and had a previous history of leishmaniasis. Fine needle aspiration cytology samples from skin nodules revealed Leishmania amastigotes.

Some pharmacological studies with Cycleanine, a diphenylbisbenzylisoquinoline alkaloid from Stephania hernandifolia

  • Maitra, Suparna;Seal, Tapan;Mallik, Sujit;Khasnobis, Arnab;Nandi, RP;Vedasiromoni, J. Rajan;Mukherjee, Biswapati
    • Advances in Traditional Medicine
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    • v.3 no.3
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    • pp.123-128
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    • 2003
  • Stephania hernandifolia belonging to the family Menispermaceae is the biggest storehouse of diphenylbisbenzylisoquinoline (DBBI) alkaloids. Exhaustive chemical processing of the bulb of S. hernandifolia by the application of modern separation techniques yielded a DBBI alkaloid which was identified as cycleanine using spectroscopic methods (UV, IR, $^1HNMR$. $^{13}CNMR$, Mass). Cycleanine showed significant anti-inflammatory activity against carrageenin induced paw oedema, comparable to that produced by diclofenac sodium, used as standard drug. It exhibited potent analgesic effects against chemical and thermal noxious stimuli. It was also found to possess anticonvulsive activity in the strychnine induced convulsion model.

An Alternative X-ray Diffraction Analysis for Comprehensive Determination of Structural Properties in Compositionally Graded Strained AlGaN Epilayers

  • Das, Palash;Jana, Sanjay Kumar;Halder, Nripendra N.;Mallik, S.;Mahato, S.S.;Panda, A.K.;Chow, Peter P.;Biswas, Dhrubes
    • Electronic Materials Letters
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    • v.14 no.6
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    • pp.784-792
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    • 2018
  • In this letter, a standard deviation based optimization technique has been applied on High Resolution X-ray Diffraction symmetric and asymmetric scan results to accurately determine the Aluminum molar fraction and lattice relaxation of Molecular Beam Epitaxy grown compositionally graded Aluminum Gallium Nitride (AlGaN)/Aluminum Nitride/Gallium Nitride (GaN) heterostructures. Mathews-Blakeslee critical thickness model has been applied in an alternative way to determine the partially relaxed AlGaN epilayer thicknesses. The coupling coefficient determination has been presented in a different perspective involving sample tilt method by off set between the asymmetric planes of GaN and AlGaN. Sample tilt is further increased to determine mosaic tilt ranging between $0.01^{\circ}$ and $0.1^{\circ}$.

Evidence of Indigenous NAB Plasmid of Naphthalene Degrading Pseudomonas putida PpG7 Strain Implicated in Limonin Degradation

  • Ghosh, Moushumi;Ganguli, Abhijit;Mallik, Meenakshi
    • Journal of Microbiology
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    • v.44 no.5
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    • pp.473-479
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    • 2006
  • A well characterized naphthalene-degrading strain, Pseudomonas putida PpG7 was observed to utilize limonin, a highly-oxygenated triterpenoid compound as a sole source of carbon and energy. Limonin concentrations evidenced a 64% reduction over 48 h of growth in batch cultures. Attempts were made to acquire a plasmid-less derivative via various methods (viz. Ethidium Bromide, SDS, elevated temperature & mitomycin C), among which the method involving mitomycin C ($20{\mu}g/ml$) proved successful. Concomitant with the loss of plasmid in P. putida PpG7 strain, the cured derivative was identified as a $lim^-$ phenotype. The $lim^+$ phenotype could be conjugally transferred to the cured derivative. Based on the results of curing with mitomycin C, conjugation studies and presence of ndo gene encoding naphthalene 1,2 dioxygenase, it was demonstrated that genes for the limonin utilization were encoded on an 83 kb indigenous transmissible Inc. P9 NAH plasmid in Pseudomonas putida PpG7 strain.

The Role of Quality of Relations in Succession Planning of Family Businesses in India

  • Merchant, Parimal;Kumar, Arya;Mallik, Debasis
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.3
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    • pp.45-56
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    • 2017
  • Considerable research has been done on the issue of succession in family businesses. However the process of induction, of preparing the members of the next generation for joining the family business has not been examined in detail. This paper attempts to analyse the relevance of three critical factors - 'quality of relations', 'willingness of the inductee' and 'the ability to manage tensions harmoniously' - to the induction process and the progress of the business. It focuses on the Indian context, specifically in the Small and medium Enterprise (SME) area. Qualitative research has been carried out. The Case Study method is used and data has been gathered from two families (including two branches of one family), using frequent unstructured interviews, over a period of five years. It is concluded that positive impact on business, family and the inductee depends to a large extent on the quality of relations, willingness of the inductee and the ability of both the inductor and inductee to handle and manage the tensions. Thus the findings of the study extend current understanding about succession drivers to the specific context of eastern cultural and developing economy represented by the Indian family businesses in the small and medium enterprise sector.