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Determining the relationship between chemical composition and size, shape and effective density of airborne fine particles through concurrent use of inertial and optical based measurements

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Particuology 2016年第5期14卷 93-101页

作者： Anand Kumar tarun Gupta Environmental Engineering and Management Program Indian Institute of Technology Kanpur Kanpur 208016 India Institute of Atmospheric and Climate Science Swiss Federal Institute of Technology Zurich Zurich 8092 Switzerland Department of Civil Engineering Indian Institute of Technology Kanpur Kanpur 208016 India

This study presents the development of a medium flow, multiple slit based PM2.5 （particle aerodynamic diameter 〈2.5 μm） inertial impactor. Its performance was compared with that of a light scattering based optical particle sizer in a field study and in controlled lab based experiments using polydisperse dolomite powder as test aerosol. The impactor＇s optimum nozzle configuration had a cutoff size of 2.51 μm （aero- dynamic diameter） at an operating flow rate of 215 L/rain with a pressure drop of 0.35 kPa across the impactor stage. Because the apparent particle density of an ambient aerosol depends on the physical properties and the chemical composition of the particles, the PM2.5 mass concentration was measured with an optical particle sizer and an inertial impactor over a weekday and a weekend day in a field study during which the effective particle shape factor and density were in tandem modified in order to com- pare the results from the two sampling techniques. The correlation of the two instrument results tended towards 1：1 with increasing values of shape factor （irregular shaped） and effective particle density. This observation was supported through chemical investigations of the collected mass, which showed a higher percentage contribution from elements which are mostly of crustal nature （namely, Ca, Fe, and Mg）.

关键词： lmpactor PM2.5 Optical particle counter Effective particle density Shape factor

Effect of relaxation times on circular crested waves in thermoelastic diffusive plate

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Applied Mathematics and Mechanics(English Edition) 2010年第4期31卷 493-500页

作者： Rajneesh KUMAR tarun KANSAL Department of Mathematics Kurukshetra University

The propagation of circularly crested thermoelastic diffusive waves in an infinite homogeneous transversely isotropic plate subjected to stress free, isothermal/insulated and chemical potential conditions is investigated in the framework of different thermo- elastic diffusion theories. The dispersion equations of thermoelastic diffusive Lamb type waves are derived. Some special cases of the dispersion equations are also deduced.

关键词： wave propagation transversely generalized thermoelastic diffusion attenuation isotropic crested waves phase velocity coefficient amplitudes

Propagation of Rayleigh waves on free surface of transversely isotropic generalized thermoelastic diffusion

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Applied Mathematics and Mechanics(English Edition) 2008年第11期29卷 1451-1462页

作者： Rajneesh Kumar tarun Kansal Department of Mathematics Kurukshetra UniversityKurukshetra-136 119India

The present paper is devoted to the study of Rayleigh wave propagation in a homogeneous, transversely isotropic, thermoelastic diffusive half-space, subject to stress free, thermally insulated/isothermal, and chemical potential boundary conditions in the context of the generalized thermoelastic diffusion theory. The Green-Lindsay（GL） theory is used in the study. In this theory, thermodiffusion and thermodiffusion mechanical relaxations are governed by four different time constants. Secular equations for surface wave propagation in the considered media are derived. Anisotropy and diffusion effects on the phase velocity, attenuation coefficient are graphically presented in order to present the analytical results and make comparison. Some special cases of frequency equations are derived from the present investigation.

关键词： wave propagation transversely isotropic generalized thermoelastic diffusion phase velocity attenuation coefficient

Viscosity and Diffusion Effects at the Boundary Surface of Viscous Fluid and Thermoelastic Diffusive Solid Medium

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Advances in Applied Mathematics and Mechanics 2011年第2期3卷 219-238页

作者： Rajneesh Kumar tarun Kansal Department of Mathematics Kurukshetra UniversityKurukshetra-136119India

This paper concentrates on the wave motion at the interface of viscous compressible fluid half-space and homogeneous isotropic,generalized thermoelastic diffusive *** wave solutions in both the fluid and thermoelastic diffusive half-spaces have been investigated;and the complex dispersion equation of leaky Rayleigh wave motion have been *** phase velocity and attenuation coefficient of leaky Rayleigh waves have been computed from the complex dispersion equation by using the Muller’s *** amplitudes of displacements,temperature change and concentration have been *** effects of viscosity and diffusion on phase velocity and attenuation coefficient of leaky Rayleigh waves motion for different theories of thermoelastic diffusion have been depicted graphi*** magnitude of heat and mass diffusion flux vectors for different theories of thermoelastic diffusion have also been computed and represented graphically.

关键词： Viscous compressible fluid isotropic thermoelastic diffusion phase velocity attenuation coefficient.

Hybrid Bio-based Composites from Waste Chicken Feather and Betel Nut Fiber: A Study on the Mechanical and Thermal Properties

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Journal of Bionic Engineering 2022年第1期19卷 268-277页

作者： Gitashree Gogoi Chayanika Chowdhury tarun K.Maji Department of Chemical Sciences Tezpur UniversityAssam784028India

The present work is an attempt to develop bio-based hybrid composites by incorporating Betel nut Fiber(BF)and Chicken feather Fiber(CF)at different ratios in modified soybean oil matrix by compression molding *** ratio of the fiber and resin was taken as 30:*** soybean oil(ESO)was modified by using methacrylic acid and methacrylic *** ratio of CF and BF was varied from 2:1 to 1:2 *** influence of hybrid fibers and fiber ratio on various properties of the composites was *** obtained results showed that composites prepared with 1:1 ratio of CF and BF exhibited highest tensile strength compared to the other composites prepared by using different ratios of CF and *** surface morphology of the composites was studied by Scanning Electron Microscopy(SEM),where surface roughness was found to be decreased after incorporation of hybrid *** analysis was carried out to study the behaviour of the composites at high temperature,where thermal stability was found to enhance for hybrid composites compared to the composites prepared with single *** properties like water vapour uptake capacity and volumetric swelling were measured and found to be decreased for the hybrid *** overall improvement in properties was observed for composites having 1:1 ratio of CF:***,it is concluded that 1:1 weight ratio of CF and BF is the optimum mixing ratio to enhance the various properties of the hybrid composites.

关键词： Hybrid composites Betel nut fiber Chicken feather fiber Mechanical properties Thermal properties

Simpler Mass Production of Polymeric Visual Decoys for the Male Emerald Ash Borer （Agrilusplanipennis）

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Journal of Bionic Engineering 2015年第2期12卷 263-269页

作者： tarun Gupta Stephen E. Swiontek Akhlesh Lakhtakia Department of lndustrial and Manufacturing Engineering Western Michigan University Kalamazoo Michigan 49008 USA Department of Engineering Seience & Mechanics Pennsylvania State University Univelitv Park Pennwlvania 16802 USA

Polymeric visual decoys of beetle of an invasive species called the Emerald Ash Borer （EAB）, Agrilus planipennis, are highly efficacious in luring and trapping EAB males. Although industrially scalable, the bioreplication process to t）tbricate these decoys involves several operational steps. In a simpler bioreplication process devised by us, a multi-cavity negative die of nickel is made from an array of several EAB females. This die is used to fabricate multiple decoys simultaneously by casting and ihermal curing of poly（dimethyl siloxane）. Finally, the decoys are sprayed by first a black paint and then a metallic green paint. The new bioreplication process has considerably fewer operational steps than its predecessor and can be adopted by industry.

关键词： artificial visual decoy bioreplication Confomlal-Evaporated-Film-by-Rotation (CEFR) method electroforming,Emerald Ash Borer negative die

Effects of rotation and tidal distortions on the shapes of radial velocity curves of polytropic models of pulsating variable stars

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Research in Astronomy and Astrophysics 2018年第6期18卷 17-26页

作者： tarun Kumar Arvind Kumar Lal Ankush Pathania School of Mathematics Thapar University

Anharmonic oscillations of rotating stars have been studied by various authors in literature to explain the observed features of certain variable stars. However, there is no study available in literature that has discussed the combined effect of rotation and tidal distortions on the anharmonic oscillations of stars. In this paper, we have created a model to determine the effect of rotation and tidal distortions on the anharmonic radial oscillations associated with various polytropic models of pulsating variable stars. For this study we have used the theory of Rosseland to obtain the anharmonic pulsation equation for rotationally and tidally distorted polytropic models of pulsating variable stars. The main objective of this study is to investigate the effect of rotation and tidal distortions on the shapes of the radial velocity curves for rotationally and tidally distorted polytropic models of pulsating variable stars. The results of the present study show that the rotational effects cause more deviations in the shapes of radial velocity curves of pulsating variable stars as compared to tidal effects.

关键词： stars: rotation stars: oscillations stars: binaries technique: radial velocities

HERMAN RINGS WITH SMALL PERIODS AND OMITTED VALUES

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Acta Mathematica Scientia 2018年第6期38卷 1951-1965页

作者： tarun Kumar CHAKRA Gorachand CHAKRABORTY Tarakanta NAYAK School of Basic Sciences Indian Institute of Technology Bhubaneswar Department of Mathematics Goverment General Degree College

All possible arrangements of cycles of three periodic as well as four periodicHerman rings of transcendental meromorphic functions having at least one omitted value aredetermined. It is shown that if p = 3 or 4, then the number of p-cycles of Herman rings isat most one. We have also proved a result about the non-existence of a 3-cycle and a 4-cycleof Herman rings simultaneously. Finally some examples of functions having no Herman ringare discussed.

关键词： omitted values Herman rings and transcendental meromorphic functions

Frequency and risk factors of low immunoglobulin levels in patients with inflammatory bowel disease

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Gastroenterology Report 2015年第2期3卷 115-121页

作者： tarun Rai Xianrui Wu Bo Shen Departments of General Internal Medicine and Gastroenterology/Hepatology the Cleveland Clinic FoundationClevelandOHUSA

Background and aims:Inflammatory bowel diseases(IBD)are considered to be dysregulated,immune-mediated disorders;and immunosuppressive medications are the mainstay of their ***,we have often observed low serum immunoglobulin(Ig)levels in these *** aim of this study was to assess the frequency and risk factors of secondary humoral immunodeficiency in IBD ***:We conducted a cross-sectional study of eligible IBD patients with Crohn’s disease(CD),ulcerative colitis(UC),indeterminate colitis(IC)or restorative proctocolectomy with ileal pouch,who having serum Ig *** and clinical variables were *** and multivariate analyses were ***:A total of 324 patients was included,with a mean age of 38.8 years and 158(48.8%)being *** IgG,IgG1,IgA,and IgM were found in 22.7%,23.4%,7.9%,and 10.9%of patients,*** shared risk factors for a low IgG or IgM level were increasing age[odds ratio(OR)=1.13;95%confidence interval(CI)1.03–1.23 for low IgG level and OR=1.33;95%CI 1.15–1.56 for low IgM level]and hypoalbuminemia(OR=1.83;95%CI 1.01–3.33 for low IgG level and OR=3.17;95%CI 1.23–8.15 for low IgM level).In addition,thioprine use was associated with low IgA level(OR=2.76;95%CI 1.03–7.39).IBD disease duration was a risk factor for low IgG1 level(OR=1.40;95%CI 1.12–1.76).The presence of concurrent primary sclerosing cholangitis(OR=0.064;95%CI 0.007–0.60)and the use of biologics(OR=0.16;95%CI 0.033–0.79)were associated with normal IgG1 *** level was lower in CD patients than that in UC/IC and ileal pouch patients(P=0.042).IgG and IgA levels were elevated in patients with inflammatory conditions of the pouch(P=0.01;P=0.003,respectively).Conclusions:Low Ig level appears to be common in IBD *** age,disease duration and hypoalbuminemia appeared to be risk *** findings may provide rationale for targeted therapy to boost humoral immunity in selected patients with IBD.

关键词： inflammatory bowel disease immunoglobulins biologics Crohn’s disease ulcerative colitis ileal pouch