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Fabrication of core-shell PLGA/PLA-pNIPAM nanocomposites for improved entrapment and release kinetics of antihypertensive drugs

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Particuology 2018年第5期16卷 169-176页

作者： Tanushree Basu Bonamali pal Satnam singh School of Chemistry and Biochemistry Thapar lnstitute of Engineering and TechnologyPatiala 147004Punjablndia

Polylactic acid (PLA)and poly(lactic-co-glycolic)acid (PLGA)are two commonly applied biodegrad- able polymers for the preparation of nanocomposites used in drug-delivery ***,these polymers lack desirable attributes such as resistance to aggregation during long-term storage due to *** improve their efficacy,in this work,PLA and PLGA were encapsulated within a shell of poly(N-isopropylacrylamide)(pNIPAM)using a single emulsion technique followed by an aqueous free radical precipitation polymerisation process,yielding core-shell PLA/PLGA-pNIPAM nanocomposites. The nanocomposites were cbaracterised using zeta potential,dynamic light scattering,and transmission electron microscopy analyses and were further applied as a delivery system for ramipril,an antihypertensive *** drug-loaded PLGA-pNIPAM core-shell nanoparticles exhibited a higher drug content (91%)and entrapment efficiency (78%)than their PLA *** in vitro release study of the formulations at pH 7.3in phosphate-buffered saline indicated that PLGA was more efficient than PLA with a sustained release of 86% of ramipril from the polymer matrix within ***,to determine the release kinetics,the data were fitted to Korsmeyer-Peppas and Higuchi models;the release of ramipril from the polymer matrix followed zero-order rate kinetics and an anomalous (non-Fickian)diffusion mechanism.

关键词： Poly(lactic-co-glycolic)acid Polylactic acid Poly(N-isopropylacrylamide) Antihypertensive drug Entrapment efficiency Drug release

Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 727-736页

作者： singh Jatinder pal GIROD Bernd Deutsche Telekom Laboratories Ernst-Reuter-Platz 7 Berlin 10587 Germany Information System Laboratory Stanford University California 94305 USA

The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the video to be delivered over the chosen links. The routing and rate allocation procedures impact the sustained quality of each video stream measured as the mean squared error (MSE) distortion at the receiver, and the overall network congestion in terms of queuing delay per link. We study the trade-off between these two competing objectives in a convex optimization formulation, and discuss both centralized and dis- tributed solutions for joint routing and rate allocation for multiple streams. For each stream, the optimal allocated rate strikes a balance between the selfish motive of minimizing video distortion and the global good of minimizing network congestions, while the routes are chosen over the least-congested links in the network. In addition to detailed analysis, network simulation results using ns-2 are presented for studying the optimal choice of parameters and to confirm the effectiveness of the proposed measures.

关键词： Ad-hoc wireless networks, Video streaming, Rate allocation, Multi-path routing

Analytical solutions fractional order partial differential equations arising in fluid dynamics

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Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 458-468页

作者： Sidheswar Behera Jasvinder singh pal Virdi Department of Physics Veer Surendra Sai University of TechnologyOdishaIndia

This article describes the solution procedure of the fractional Pade-Ⅱ equation and generalized Zakharov equation(GSEs)using the sine-cosine ***-Ⅱ is an important nonlinear wave equation modeling unidirectional propagation of long-wave in dispersive media and GSEs are used to model the interaction between one-dimensional high,and low-frequency *** of trigonometric and hyperbolic function solutions in fractional calculus are *** simulations of the numerical solutions are flaunted by MATLAB.

关键词： the sine-cosine method He's fractional derivative analytical solution fractional Pade-Ⅱequation fractional generalized Zakharov equation

SiO2-coated pure anatase TiO2 catalysts for enhanced photo-oxidation of naphthalene and anthracene

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Particuology 2017年第5期15卷 156-161页

作者： Inderpreet singh Grover Roop Chand Prajapat Satnam singh Bonamali pal Department of Chemistry Public College Samana 147101 Punjab India School of Chemistry and Biochemistry Thapar University Putiala 147004 Punjab India

Our current efforts reveal the preparation of SiO2@TiO2 nanocomposites having different thicknesses of silica shell and the relationship to photocatalytic activity （PCA） for the photo-oxidation of naph-thalene and anthracene. The presence of SiO2 coating over TiO2 surface was demonstrated by FT-IR analysis, with peaks corresponding to Si-O-Si （1081 cm 1） and Si-O-Ti （950 cm-1） bonds observed. High-resolution transmission electron microscopy analysis confirmed the presence of SiO2 in the as- prepared nanocomposites and the amount of Si, Ti, and O was determined by energy dispersive X-ray spectroscopy analysis. Increasing the Si02 shell thickness increases the surface area of the nanocompos- ites （69-235 m2/g）, which enhances naphthalene/anthracene adsorption. However, the observed PCA trend presents an inverse correlation to the adsorption studies, where the as-prepared samples possess- ing the highest surface areas exhibited the least PCA, while catalysts having lower surface areas （among silica coated samples） displayed the highest PCA in the degradation of naphthalene and anthracene to CO2. Despite complete degradation of naphthalene and anthracene, incomplete mineralization occurred, ascribed to the formation of various intermediates, identified by GC-MS analysis.

关键词： Silica coating Naphthalene Anthracene Photo-oxidation TiO2 nanoparticles

Modeling oblique load carrying capacity of batter pile groups using neural network,random forest regression and M5 model tree

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 674-685页

作者： Tanvi singh Mahesh pal V.K.ARORA Department of Civil Engineering National Institute of TechnologyKurukshetraHaryana 136119India

M5 model tree,random forest regression(RF)and neural network(NN)based modelling approaches were used to predict oblique load carrying capacity of batter pile groups using 247 laboratory experiments with smooth and rough pile *** length(L),angle of oblique load(a),sand density(ρ),number of batter piles(B),and number of vertical piles(V)as input and oblique load(Q)as output was *** suggest improved performance by RF regression for both pile groups.M5 model tree provides simple linear relation which can be used for the prediction of oblique load for field data *** developed using RF regression approach with smooth pile group data was found to be in good agreement for rough piles *** based approach was found performing equally well with both smooth and rough *** analysis using all three modelling approaches suggest angle of oblique load(a)and number of batter pile(B)affect the oblique load capacity for both smooth and rough pile groups.

关键词： batter piles oblique load test neural network M5 model tree random forest regression ANOVA

EFFECTS OF DELAY AND SEASONALITY ON TOXIN PRODUCING PHYTOPLANKTON-ZOOPLANKTON SYSTEM

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International Journal of Biomathematics 2012年第5期5卷 239-259页

作者： SUNITA GAKKHAR ANURAJ singh BRAHAM pal singh Department of MathematicsIndian Institute of Technology Roorkee Roorkee 247667 Uttarakhand India Department of Mathematics J. V. Jain Degree CollegeSaharanpur 2~001 U.P. India

A dynamical model for toxin producing phytoplankton and zooplankton has been formu- lated and analyzed. Due to gestation of prey, a discrete time delay is incorporated in the predator dynamics. The stability of the delay model is discussed and Hopf bifurcation to a periodic orbit is established. Stability and direction of bifurcating periodic orbits are investigated using normal form theory and center manifold arguments. Global existence of periodic orbits is also established. To substantiate analytical findings, numerical simu- lations are performed. The system shows rich dynamic behavior including chaos and limit cycles. The influence of seasonality in intrinsic growth parameter of the phytoplankton population is also investigated. Seasonality leads to complexity in the system.

关键词： Time delay stability Hopf bifurcation period chaos.

Relationship between species richness,taxonomic distinctness,functional diversity,and local contribution toβdiversity and effects of habitat disturbance in the riparian spider community of the Ganga River,India

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Ecological Processes 2023年第1期12卷 204-216页

作者： Kritish De amar Paul singh Arkojyoti Sarkar Kritika singh Manju Siliwal Virendra Prasad Uniyal Syed Ainul Hussain Wildlife Institute of India ChandrabaniDehradun 248001India Present Address:Department of Life Sciences Sri Sathya Sai University for Human ExcellenceNavanihalOkali PostKamalapurKalaburagiKarnataka 585313India

Background In the riverine riparian ecosystem,particularly in India,the knowledge of the effects of habitat disturbance on taxonomic distinctness,functional diversity,and local contribution toβdiversity(LCBD)of spider community is *** present study examined the relationships between the index of taxonomic distinctness(Δ^(+)),index of variation in taxonomic distinctness(λ^(+)),functional evenness(FEve),functional divergence(FDiv),functional dispersion(FDis),and LCBD of spider community of the Ganga River and the effects of habitat disturbance on these indices.A total of 27 sampling sites were selected along the bank of the Ganga *** on the rating of the disturbance scores,the sites were classified into lowly,moderately,and highly disturbed *** understand the relationships between species richness,Δ^(+),λ^(+),FDis,FDiv,FEve,LCBD,and habitat disturbance score,Pearson’s correlation was calculated,followed by the linear regression *** one-way multivariate analysis of variance was used to find differences in taxonomic distinctness and functional diversity in the different disturbed *** Significant relationships were found betweenλ^(+)andΔ^(+),FDis andΔ^(+),FDis andλ^(+),FDiv and species richness,FEve and species richness,FEve andλ^(+),FEve and habitat disturbance,LCBD and FEve,and LCBD and habitat disturbance.A significant difference was present in the indices of functional diversity between the lowly,moderately,and highly disturbed ***,garbage dump,human settlement,and created embankment influenced the spider community’sλ^(+),FEve,and *** Unrestrained anthropogenic activities exacerbate habitat disturbance by affecting ecological ***,understanding linkages between ecosystem disturbance,taxonomic,functional,andβdiversity can be fundamental to managing and conserving natural *** work highlights the importance of including taxonomic and functional diversity to comprehend the impact of habit

关键词： Habitat disturbance Taxonomic distinctness Functional evenness Functional divergence Functional dispersion Local contribution to beta diversity Spider community Riparian area Ganga River

Pipes with Trapezoidal Cut Twisted Tape Inserts in the Laminar Flow Regime:Nusselt Number and Friction Coefficient Analysis

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Fluid Dynamics & Materials Processing 2023年第2期19卷 501-511页

作者： Shrikant Arunrao Thote Netra pal singh Department of Mechanical Engineering Oriental UniversityIndore453555India

The thermal behavior of pipes with a twisted tape inside(used to enhance heat transfer through the tube wall)is studied in the laminar flow *** is used as the work fluid with the corresponding Reynolds Number spanning the interval 200–*** is found that in such conditions the‘Nusselt Number’(Nu)gradually increases with reducing the tape twist ratio,whereas the friction factor is detrimentally affected by the presence of the tape(as witnessed by the comparison with the companion case where a plain tube is considered).In particular,it is shown that the heat transfer efficiency can be improved by nearly 69%if tape inserts with a relatively low twist ratio are *** the basis of these findings,it is concluded that loose fit tape inserts are superior to tight fit tapes in terms of heat transfer and ease of replacement.

关键词： Friction factor laminar flow Nusselt Number trapezoidal-cut twisted tape

Analysis of Friction and Heat Transfer Characteristics of Tubes with Trapezoidal Cut Twisted Tape Inserts

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Fluid Dynamics & Materials Processing 2023年第3期19卷 711-722页

作者： Shrikant Arunrao Thote Netra pal singh Department of Mechanical Engineering Oriental UniversityIndore453555India

The thermo-hydraulic properties of circular tubes with a twisted tape inside(used accordingly to induce turbulence and enhance heat transfer through the tube wall)are described for Reynolds Numbers ranging from 830 to *** twisted with the three distinct twist ratios are considered,namely,6,4.4 and *** is used as the working fluid in several *** the sake of comparison,the standard tube with no insert is also *** is shown that in the presence of the twisted tape,the‘frictional factor’,‘Nusselt Number’and the‘thermal performance factor’are much higher than those obtained for the plain ***,the tapes having the lowest twist ratio,i.e.,3,are more effective than the others in terms of heat transfer ***‘thermal performance factor’is greater than one for all the twisted tapes used in the experiments,which confirms the enhanced performances of the heat exchanger and the related savings in terms of total energy.

关键词： Friction factor nusselt number performance ratio trapezoidal cut twisted tape insert