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INFLUENCE OF SLIP VELOCITY ON BLOOD FLOW THROUGH AN ARTERY WITH PERMEABLE WALL： A THEORETICAL STUDY

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International Journal of Biomathematics 2012年第5期5卷 147-166页

作者： A. sinha J. C. MISRA School of Medical Science and Technologyindian Institute of Technology Kharagpur-721302 India Department of 1Vlathematics Institute of Technical Education and ResearchSiksha 0 Anusandhan University Bhubaneswar India

A theoretical investigation concerning the influence of slip velocity on the flow of blood through an artery having its wall permeable has been carried out. Here blood is treated as a homogeneous Newtonian fluid. The flow is characterized by three parameters： /3 the ratio of radius to length of the arterial segment, Re the characteristic Reynolds number associated with the pressure outside the arterial segment and c the filtration coe^cient. The problem has been solved by the use of a perturbation technique, e is considered to be very small, ensuring the validity of the perturbation method. The computed numerical results are presented graphically to depict the variations in velocity, volumetric flow rate, wall shear stress and flow resistance.

关键词： Slip velocity permeable artery newtonian fluid.

Phenylboronic acids in crystal engineering:Utility of the energetically unfavorable syn,syn-conformation in co-crystal design

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Science China Chemistry 2011年第12期54卷 1909-1919页

作者： VARUGHESE Sunil sinha Shashi Bhushan DESIRAJU Gautam R. Solid State and Structural Chemistry Unit Indian Institute of Science

Phenylboronic acids can exist, in principle, in three different conformers （syn, syn; syn, anti and anti, anti） with distinct energy profiles. In their native state, these compounds prefer the energetically favored syn, anti-conformation. In molecular complexes, however, the functionality exhibits conformational diversity. In this paper we report a series of co-crystals, with N-donor compounds, prepared by a design strategy involving the synthons based on the syn, syn-conformation of the boronic acid functionality. For this purpose, we employed compounds with the 1,2-diazo fragment （alprazolam, 1H-tetrazole, acetazolamide and benzotriazole）, 1,10-phenanthroline and 2,2＇-bipyridine for the co-crystallization experiments. However, our study shows that the mere presence of the 1,2-diazo fragment in the coformer does not guarantee the successful formation of co-crystals with a syn, syn-conformation of the boronic acid.

关键词： crystal engineering phenylboronic acid supramolecular synthon conformational flexibility

Deep Neural Network Based Detection and Segmentation of Ships for Maritime Surveillance

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Computer Systems Science & Engineering 2023年第1期44卷 647-662页

作者： kyamelia Roy Sheli sinha Chaudhuri Sayan Pramanik Soumen Banerjee Department of Electronics and Tele-Communication Engineering Jadavpur UniversityKolkata700032India Department of Electronics and Communication Engineering University of Engineering and ManagementKolkata700160India

In recent years,computer visionfinds wide applications in maritime surveillance with its sophisticated algorithms and advanced ***-matic ship detection with computer vision techniques provide an efficient means to monitor as well as track ships in water *** being an important medium of transport require continuous monitoring for protection of national *** remote sensing satellite images of ships in harbours and water bodies are the image data that aid the neural network models to localize ships and to facilitate early identification of possible threats at *** paper proposes a deep learning based model capable enough to classify between ships and no-ships as well as to localize ships in the original images using bounding box ***,classified ships are again segmented with deep learning based auto-encoder *** proposed model,in terms of classification,provides suc-cessful results generating 99.5%and 99.2%validation and training accuracy *** auto-encoder model also produces 85.1%and 84.2%validation and training *** the IoU metric of the segmented images is found to be of 0.77 *** experimental results reveal that the model is accu-rate and can be implemented for automatic ship detection in water bodies consid-ering remote sensing satellite images as input to the computer vision system.

关键词： Auto-encoder computer vision deep convolution neural network satellite imagery semantic segmentation ship detection

Retinal structural-vascular-functional relationship using optical coherence tomography and optical coherence tomography -angiography in myopia

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Eye and Vision 2019年第1期6卷 51-62页

作者： Ramesh Venkatesh Shivani sinha Deepika Gangadharaiah Santosh G.k.Gadde Ashwin Mohan Rohit Shetty Naresh kumar Yadav Department of Retina and Vitreous Narayana Nethralaya#121/C1st R BlockChord RoadRajaji NagarBengaluru 560010India. Department of Cornea and Refractive surgery Narayana Nethralaya#121/C1st R BlockChord RoadRajaji NagarBengaluru 560010India

Background:To examine the retinal structure–vascular-function relationship using optical coherence tomography(OCT)and optical coherence tomography angiography(OCTA)in ***:This was a prospective cross-sectional study comprising 86 eyes of 45 individuals with varying axial lengths and spherical equivalents and no posterior segment *** eyes underwent optical coherence tomography with the Spectralis SD-OCT and OCTA with RTVue-XR Avanti;*** macular retinal layer thicknesses and flow areas and vessel densities were measured on OCT and OCTA,*** correlations were made between the macular layer thicknesses,flow areas and vessel densities with axial length,spherical equivalent and visual ***:The participants’mean ages were 33.34±14.45 years,mean spherical equivalent refractions were−7.17±5.71 D and axial lengths were 25.95±2.41 *** were significant positive correlations of foveal angle(r=0.757,p=0.001),inner retinal(r=0.764,p=0.001)and outer plexiform layer(r=0.771,p=0.001)thickness on OCT and vessel densities in deep capillary plexus(r=0.313,p=0.003)on OCTA with axial length and negative correlations with spherical equivalents and visual *** negative correlations of outer nuclear layer(r=−0.560,p=0.03)and photoreceptor outer segment layer thickness(r=−0.856,pkness,vascular density and visual acuity in these *** research is required to investigate this.

关键词： Myopia Axial elongation Spherical equivalent OCT Optical coherence tomography angiography Structure Visual acuity

Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation

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Advances in Atmospheric Sciences 1992年第4期9卷 431-440页

作者： S.k.sinha S.G.Narkhedkar D.R.Talwalkar S.Rajamani Indian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 IndiaIndian Institute of Tropical Meteorology Pune 411008 India

A two-dimensional, multitvariate objective analysis scheme for simultaneous analysis of geopotential height and wind fields has been developed over Indian and adjoining region for use in numerical weather prediction. The height-height correlations calculated using daily data of four July months (1976-1979), are used to derive the other autocorrelations and cross-correlations assuming geostropic relationship. A Gaussian function is used to model the autocorrelation function. Since the scheme is multivariate the regression coefficients (weights) are *** the equator, the geostrophic approximation relating mass and wind is decoupled in a way similar to Bergman (1979). The objective analyses were made over Indian and adjoining region for 850, 700, 500, 300 and 200 hPa levels for the period from 4 July to 8 July 1979, 12 GMT. The analyses obtained using multivariate optimum interpolation scheme depict the synoptic situations satisfactorily. The analyses were also compared with the FGGE analyses (from ECMWF) and also with the station observations by computing the root mean square (RMS) errors and the RMS errors are comparable with those obtained in other similar studies.

关键词： In Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation

Oscillatory blood flow through a capillary in presence of thermal radiation

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International Journal of Biomathematics 2015年第1期8卷 181-199页

作者： A. sinha G. C. Shit Department of Mathematics Jadavpur University Kolkata West Bengal 700032 India

This paper deals with the theoretical investigation of a fundamental problem of magne- tohydrodynamic （MHD） flow of blood in a capillary in the presence of thermal radiation and chemical reaction. The unsteadiness in the flow and temperature fields is caused by the time-dependence of the stretching velocity and the surface temperature. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a third-order fluid. The problem is first reduced to solving a system of coupled nonlinear differential equations involving several parameters. Considering blood as an electrically conducting fluid and using the present analysis, an attempt is made to compute some parameters of the blood flow by developing a suitable numerical method and by devising an appropri- ate finite difference scheme. The computational results are presented in graphical form, and thereby some theoretical predictions are made with respect to the hemodynamical flow of the blood in a hyperthermal state under the action of a magnetic field. Com- putational results for the variation in velocity, temperature, concentration, skin-friction coefi^icient, Nusselt number and Sherwood number are presented in graphical/tabular form. Since the study takes care of thermal radiation in blood flow, the results reported here are likely to have an important bearing on the therapeutic procedure of hyperthermia, particularly in understanding blood flow and heat transfer in capillaries.

关键词： Third-order fluid stretching wall thermal radiation oscillatory motion

Optimization of organic light emitting diode for HAT-CN based nano-structured device by study of injection characteristics at anode/organic interface

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Frontiers of Optoelectronics 2019年第3期12卷 268-275页

作者： Neha JAIN O. P. sinha Sujata PANDEY Department of Electronics and Communication Engineering Amity University UPNoidaIndia Amity Institute of Nanotechnology Amity University UPNoidaIndia Department of Electronics and Telecom Engineering Amity University UPNoidaIndia

To increase the current density of the hole only device, 1, 4, 5, 8, 9, 11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) material has been inserted in the device at the indium tin oxide (ITO)/organic interface. Since HATCN molecule can withdraw electrons, it can alter electronic properties of the electrodes and hence inserted between the organic/metal interfaces. This paper deals with the optimization of the thickness of organic-metal layers to enhance the efficiency. Also, efforts have been made to increase the current density and reduce the operating voltage of the device. The material 2, 7-bis [N, N-bis (4- methoxy-phenyl) amino]-9, 9-spirobifluorene (Meo-Spiro-TPD) is used to simulate the hole only device because it is a thermally stable hole transport material. Simulated results shows that better current density values can be achieved compared to fabricated one by optimizing the organic metal layer thickness. The best optimized layer thickness of 22 nm for Alq3, 25 nm for *CBP doped with Ir(ppy)3, 9 nm for Meo-Spiro TPD and 4 nm for HAT-CN which results in current density of 0.12 A/cm2 with a reduction in operating voltage by approximately 2 V.

关键词： organic light emitting diode (OLED) 2 7-bis [NV-bis (4-methoxy-phenyl) amino]-9 9-spirobifluorene (Meo-Spiro-TPD) indium tin oxide (ITO) model higher occupied molecular orbital (HOMO) lower unoccupied molecular orbital (LUMO)

Dielectric Relaxation and Conductivity of Ba(Mg_(1/3)Ta_(2/3))O_3 and Ba(Zn_(1/3)Ta_(2/3))O_3

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Journal of Materials Science & Technology 2014年第4期30卷 311-320页

作者： Md.Monwar Hoque Alo Dutta Sanjay kumar Tripurari Prasad sinha Department of Physics Jadavpur University Department of Physics Bose Institute

The frequency dependent dielectric properties of barium magnesium tantalate （BMT）, Ba（Mgl/3Ta2/3）03 and barium zinc tantalate （BZT）, Ba（Znl/3Ta2/3）03 synthesized by solid state reaction technique have been investigated at various temperatures by impedance spectroscopy. BMT and BZT possess cubic structure with lattice parameter a = 0.708 and 0.451 nm, respectively. The resonance peaks due to dielectric relaxation processes are observed in the loss tangent of these oxides. The relaxation in the samples is polydispersive in nature. The temperature dependence of dc conductivity, the most probable relaxation frequency （corn） obtained from tanδ vs logo） plots and ωm obtained from imaginary parts of the complex electrical modulus vs Iogω plots follow the Arrhenius behavior. According to these Arrhenius plots the activation energies of BMT and BZT are about 0.54 and 0.40 eV, respectively. Thus the results indicate that samples are semiconducting in nature. The frequency-dependent electrical data are analyzed in the framework of conductivity and electric modulus formalisms. Both these formalisms show qualitative similarities in relaxation time. Our study points that for complex perovskite oxides with general formula A（B＇B＇）03, the dielectric properties significantly depend on the atomic radii of both A and B type cations. BMT and BZT exhibit enhancement in dielectric property compared to their niobate counterparts. They may find several technological applications such as in capacitors, resonators and filters owing to their high dielectric constant and low loss tangent.

关键词： Perovskite oxides Impedance spectroscopy Dielectric properties Electrical conductivity

ALMA and GMRT Studies of Dust Continuum Emission and Spectral Lines Toward Oort Cloud Comet C/2022 E3(ZTF)

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Research in Astronomy and Astrophysics 2024年第12期24卷 81-92页

作者： Arijit Manna Sabyasachi Pal Sekhar sinha Sushanta kumar Mondal Department of Physics and Astronomy Midnapore City College Department of Physics Sidho-Kanho-Birsha University

The atomic and molecular compounds of cometary ices serve as valuable knowledge into the chemical and physical properties of the outer solar nebula, where comets are formed. From the cometary atmospheres, the atoms and gas-phase molecules arise mainly in three ways:（i） the outgassing from the nucleus,（ii） the photochemical process, and（iii） the sublimation of icy grains from the nucleus. In this paper, we present the radio and millimeter wavelength observation results of Oort cloud non-periodic comet C/2022 E3（ZTF） using the Giant Metrewave Radio Telescope（GMRT） band L and the Atacama Large Millimeter/submillimeter Array（ALMA） band 6. We do not detect continuum emissions and an emission line of atomic hydrogen（H I） at rest frequency 1420 MHz from this comet using the GMRT. Based on ALMA observations, we detect the dust continuum emission and rotational emission lines of methanol（CH3OH） from comet C/2022 E3（ZTF）. From the dust continuum emission, the dust production（Afρ） activity of comet ZTF is 2280 ± 50 cm. Based on LTE spectral modeling, the column density and excitation temperature of CH3OH toward C/2022 E3（ZTF） are（4.50 ± 0.25） × 1014cm-2and 70 ± 3 k respectively. The integrated emission maps show that CH3OH was emitted from the coma region of the comet. The production rate of CH3OH toward C/2022 E3（ZTF） is（7.32 ± 0.64） × 1026molecules s-1. The fractional abundance of CH3OH with respect to H2O in the coma of the comet is 1.52%. We also compare our derived abundance of CH3OH with the existence modeled value, and we see the observed and modeled values are quite similar. We claim that CH3OH is formed via the subsequential hydrogenation of formaldehyde（H2CO） on the grain surface of comet C/2022 E3（ZTF）.

关键词： Astrochemistry Comets: general Planets and satellites: composition Radio continuum: planetary systems Submillimeter: planetary systems