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1

Prediction of flexural strength of FRC pavements by soft computing techniques

Kimteta A., Thakur M.S., Sihag P., Upadhya A., Sharma N.

Archives of Materials Science and Engineering

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2022

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Vol. 117, nr 1

13--24

EN

Purpose: The mechanical characteristics of concrete used in rigid pavements can be improved by using fibre-reinforced concrete. The purpose of the study was to predict the flexural strength of the fibre-reinforced concrete for ten input variables i.e., cement, fine aggregate, coarse aggregate, water, superplasticizer/high range water reducer, glass fibre, polypropylene fibre, steel fibres, length and diameter of fibre and further to perform the sensitivity analysis to determine the most sensitive input variable which affects the flexural strength of the said fibre-reinforced concrete. Design/methodology/approach: The data used in the study was acquired from the published literature to create the soft computing modes. Four soft computing techniques i.e., Artificial neural networks (ANN), Random forests (RF), Random trees RT), and M5P, were applied to predict the flexural strength of fibre-reinforced concrete for rigid pavement using ten significant input variables as stated in the ‘purpose’. The most performing algorithm was determined after evaluating the applied models on the threshold of five statistical indices, i.e., the coefficient of correlation, mean absolute error, root mean square error, relative absolute error, and root relative squared error. The sensitivity analysis for most sensitive input variable was performed with out-performing model, i.e., ANN. Findings: The testing stage findings show that the Artificial neural networks model outperformed other applicable models, having the highest coefficient of correlation (0.9408), the lowest mean absolute error (0.8292), and the lowest root mean squared error (1.1285). Furthermore, the sensitivity analysis was performed using the artificial neural networks model. The results demonstrate that polypropylene fibre-reinforced concrete significantly influences the prediction of the flexural strength of fibre-reinforced concrete. Research limitations/implications: Large datasets may enhance machine learning technique performance. Originality/value: The article's novelty is that the most suitable model amongst the four applied techniques has been identified, which gives far better accuracy in predicting flexural strength.

2

Comparative study for deriving stagedischarge - sediment concentration relationships using soft computing techniques

Sihag P., Sadikhani M. R., Vambol V., Vambol S., Prabhakar A. K., Sharma N.

Journal of Achievements in Materials and Manufacturing Engineering

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2021

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Vol. 104, nr 2

57--76

EN

Purpose: Knowledge of sediment load carried by any river is essential for designing and planning of hydro power and irrigation projects. So the aim of this study is to develop and evaluating the best soft-computing-based model with M5P and Random Forest regressionbased techniques for computation of sediment using datasets of daily discharge, daily gauge and sediment load at the Champua gauging site of the Upper Baitarani river basin of India. Design/methodology/approach: Last few decades, the soft computing techniques based models have been successfully used in water resources modelling and estimation. In this study, the potential of tree based models are examined by developing and comparing sediment load prediction models, based on M5P tree and Random forest regression (RF). Several M5P and RF based models have been applied to a gauging site of the Baitarani River at Odisha, India. To evaluate the performance of the selected M5P and RF-based models, three most popular statistical parameters are selected such as coefficient of correlation, root mean square error and mean absolute error. Findings: A comparison of the results suggested that RF-based model could be applied successfully for the prediction of sediment load concentration with a relatively higher magnitude of prediction accuracy. In RF-based models Qt, Q(t-1), Q(t-2), S(t-1), S(t-2), Ht and H(t-1) combination based M10 model work superior than other combination based models. Another major outcome of this investigation is Qt, Q(t-1) and S(t-1) based model M4 works better than other input combination based models using M5P technique. The optimum input combination is Qt, Q(t-1) and S(t-1) for the prediction of sediment load concentration of the Baitarani River at Odisha, India. Research limitations/implications: The developed models were tested for Baitarani River at Odisha, India.

3

A review: sustainable compressive strength properties of concrete mix with replacement by marble powder

Sharma N., Singh Thakur M., Goel P. L., Sihag P.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 98, nr 1

11--23

EN

Purpose: Over the years, various experiments have been performed to investigate the impact of marble powder within the concrete mixture. In the present study, a review has been done to check the persistence of marble dirt as the substitute for concrete constituents. Design/methodology/approach: Furthermore, the impact of marble powder as a replacement of cement and aggregates were reviewed. By reviewing previous studies, the result indicates that the use of waste marble powder in cement and aggregate was adequate to a certain range. Findings: By replacing cement with marble powder in a range between 5% to 10% by weight, it increases the compressive strength of concrete mix by 11.30% to 24.56%, compared to the nominal mix. According to the study, any further increase in the amount of marble powder in place of cement i.e, 12.5% to 20% replacement by weight, results in the reduction of compressive strength of concrete mix by 7.5% to 26.01%. Replacement of aggregates from 5% to 75% with marble powder increases the compressive strength of about 3.22% to 23.91% as compared to the nominal mix. Research limitations/implications: It was also concluded from the current study that, to obtain higher compressive strength, it is advantageous to replace fine aggregates with marble powder than the replacement of cement with the marble powder.

4

Reflection of PlaneWaves at Micropolar Piezothermoelastic Half-space

Kumar R., Sharma N., Lata P., Marin M.

Computational Methods in Science and Technology

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2018

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Vol. 24, No. 2

113--124

EN

A problem of reflection at a free surface of micropolar orthotropic piezothermoelastic medium is discussed in the present paper. It is found that there exist five type plane waves in micropolar orthotropic piezothermoelastic medium, namely quasi longitudinal displacement wave (quasi LD wave), quasi thermal wave (quasi T wave), quasi CD-I, quasi CD-II wave and electric potential wave (PE wave). The amplitude ratios corresponding to reflected waves are obtained numerically. The effect of angle of incidence and thermopiezoelectric interactions on the reflected waves are studied for a specific model. Some particular cases of interest are also discussed.

5

A Detailed Study of EEG based Brain Computer Interface

Sharma G., Sharma N., Singh T., Agrawal R.

Annals of Computer Science and Information Systems

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2018

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Vol. 14

137--143

EN

Brain Computer Interface (BCI) generate a direct method to communicate with the outside world. Many patients are not able to communicate. For example:- the patient who are suffered with the several disease like post stroke - the process of thinking, remembering \& recognizing can be challenging. Because of spinal cord injuries or brain stem stroke the patient loss the monitoring power. EEG based brain computer interface (BCI) feature is beneficial to scale the brain movement \& convert them into a instruction for monitoring. In this paper our objective is to study about various applications of EEG based signal of the different disease like spinal cord injury, post stroke and ALS (amyotrophic lateral sclerosis) etc.

6

Prediction of indoor radon/thoron concentration in a model room from exhalation rates of building materials for different ventilation rates

Kumar M., Sharma N., Sarin A.

Acta Geophysica

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2018

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Vol. 66, no. 5

1249--1255

EN

Studies have confirmed that elevated levels of radon/thoron in the human–environments can substantially increase the risk of lung cancer in general population. The building materials are the second largest contributors to indoor radon/thoron after soil and bedrock beneath dwellings. In present investigation, the exhalation rates of radon/thoron from different building materials samples have been analysed using active technique. Radon/thoron concentrations in a model room have been predicted based on the exhalation rates from walls, floor and roof. The indoor concentrations show significant variations depending upon the ventilation rate and type of building materials used.

7

Bat optimization based neuron model of stochastic resonance for the enhancement of MR images

Singh M., Verma A., Sharma N.

Biocybernetics and Biomedical Engineering

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2017

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Vol. 37, no. 1

124--134

EN

Stochastic resonance (SR) performs the enhancement of the low in contrast image with the help of noise. The present paper proposes a modified neuron model based stochastic resonance approach applied for the enhancement of T1 weighted, T2 weighted, fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) sequences of magnetic resonance imaging. Multi objective bat algorithm has been applied to tune the parameters of the modified neuron model for the maximization of two competitive image performance indices contrast enhancement factor (F) and mean opinion score (MOS). The quality of processed image depends on the choice of these image performance indices rather the selection of SR parameters. The proposed approach performs well on enhancement of magnetic resonance (MR) images, as a result there is improvement in the gray-white matter differentiation and has been found helpful in the better diagnosis of MR images.

8

Effect of Two Temperatures and Thermal Phase-lags in a Thick Plate due to a Ring Load with Axisymmetric Heat Supply

Kumar J., Sharma N., Lata P.

Computational Methods in Science and Technology

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2016

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Vol. 22, No. 3

153--162

EN

The present investigation concerns thermomechanical interactions in a homogeneous isotropic thick plate in the light of the two-temperature thermoelasticity theory with dual phase lag due to a ring load. The upper and lower ends of the thick plate are traction free and subjected to an axisymmetric heat supply. The solution is obtained by using Laplace and Hankel transform techniques. The analytical expressions of displacement components, stresses, conductive temperature, temperature change and cubic dilatation are computed in a transformed domain. The numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results are depicted graphically. The effect of thermal phase-lags and two temperatures are shown on the various components. Some particular cases of the result are also deduced from the present investigation.

9

Determination of Deltamethrin in Mice Plasma and Immune Organs by Simple Reversed-Phase HPLC

Kumar A., Dubey R. K., Kant K., Sasmal D., Ghosh M., Sharma N.

Acta Chromatographica

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2016

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Vol. 28, no. 2

193--206

EN

Deltamethrin, a well-known type 2 synthetic pyrethroid insecticide, is a widespread environmental toxicant. It has potential to accumulate in body fluids and tissues due to its lipophilic characteristics. The immune system is among the most sensitive targets regarding toxicity of environmental pollutants. Various methods are available in the literature to analyze deltamethrin (DLM) concentration in plasma and tissues, but regarding the immune organs, only one gas chromatography–tandem mass spectrometry (GC–MS/MS) method (on spleen tissues) has been reported. In the present investigation, a rapid and sensitive high-performance liquid chromatography (HPLC) method has been developed and validated to determine DLM concentration in plasma, thymus, and spleen using zaleplone as an internal standard. Liquid chromatography (LC) separation is performed on an Agilent Zorbax® C8 column (250 mm × 4.6 mm, i.d., 5 μm) with isocratic elution using a mobile phase consisting of acetonitrile–5 mM KH2PO4 (70:30, v/v) at a flow rate of 1 mL min−1. The lower limit of quantification (LLOQ) for DLM is 10 ng mL−1 (plasma, thymus, and spleen). The method has been validated in terms of establishing linearity, specificity, sensitivity, recovery, accuracy, and precision (intra- and inter-day) and stabilities study. This validated method was successfully applied to a pharmacokinetic and tissue distribution study of DLM in mice.

10

Development and validation of a rapid and sensitive LC-MS/MS method for the determination of aripiprazole in human plasma: Application to a bioequivalence study

Patel D. S., Sharma N., Patel M. C., Patel B. N., Shrivastav P. S., Sanyal M.

Acta Chromatographica

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2014

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Vol. 26, no. 2

203--227

EN

A rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay has been proposed for the determination of aripiprazole in human plasma. The analyte and propranolol as internal standard (IS) were extracted from 200 μL of human plasma via liquid-liquid extraction using methyl tert-butyl ether under alkaline conditions. The best chromatographic separation was achieved on an Aquasil C18 (100 × 2.1 mm, 5 μm) column using methanol-deionized water containing 2 mM ammonium trifluoroacetate and 0.02% formic acid (65:35, v/v) as the mobile phase under isocratic conditions. Detection of analyte and IS was done by tandem mass spectrometry, operating in positive ion and multiple reaction monitoring (MRM) acquisition mode. The method was fully validated for its selectivity, interference check, sensitivity, carryover check, linearity, precision and accuracy, reinjection reproducibility, recovery, matrix effect, ion suppression/enhancement, stability, ruggedness, and dilution integrity. The assay was linear over the concentration range of 0.10–100 ng mL -1 for aripiprazole. The intra-batch and inter-batch precision (%CV) was ≤4.8%, while the mean extraction recovery was >96% for aripiprazole across quality control levels. The method was successfully applied to a bioequivalence study of 10 mg aripiprazole orally disintegrating tablet formulation in 27 healthy Indian subjects under fasting and fed condition. The reproducibility in the measurement of study data was demonstrated by reanalysis of 260 incurred samples.

11

Propagation of waves in generalized thermoelastic continua with two temperature

Kaushal S., Sharma N., Kumar R.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 4

1111-1127

EN

The present investigation is concerned with the following two problems. (i) Reflection and transmission of thermoelastic waves between two thermoelastic/ thermoelastic solids with two temperatures at an imperfect interface. The amplitude ratios of different reflected and transmitted waves are obtained and deduced for normal force stiffness, transverse force stiffness, thermal contact conductance and perfect bonding. The variations of amplitude ratios with angle of incidence are shown graphically for the longitudinal wave (P-wave), thermal wave (T-wave) and SV-wave. (ii) Propagation of Rayleigh waves in a thermoelastic half-space with two temperature at the free surface. The phase velocity and attenuation coefficient are obtained and presented graphically to depict the effect of two temperatures. Some special cases of interest are deduced from the present investigation.

12

Synthesis, Characterization and Thermal Studies of Niobium(V) Complexes of 2-tert-Butylphenol

Sharma N., Sharma M., Kumari M., Chaudhry S. C.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 7

1265-1276

EN

Complexes of composition [NbCl4(OC6H4C(CH3)3-2)] and [NbCl3(OC6H4C(CH3)3-2)2] have been synthesized from the reaction of niobium pentachloride with equimolar and bimolar amounts of 2-tert-butylphenol in carbon tetrachloride. The complexes have been characterized by physicochemical, IR, 1H and 13C NMR and UV-VIS spectral studies. Based upon these studies, for complexes mononuclear square-pyramidal geometry around niobium has been proposed. Thermal decompositional behaviour of the complexes has been studied by TG, DTA and DSC techniques. From TG data, the kinetic and thermodynamic parameters viz. energy of activation, frequency factor, order of reaction, entropy of activation etc. have been evaluated using Freeman-Carroll, Coats-Redfern and Horowitz-Metzger equations. The reactions of complexes with a variety of nitrogenous bases (L1–L5) (where L1 = imidazole, L2 = benzimidazole, L3 = N-methylimidazole, L4 = 2,2'-bipyridyl and L5 = 1,10-phenanthroline) yielded 1:1 addition compounds authenticated by analytical and IR spectral studies.

13

Synthesis, Characterization and Reactivity of Niobium(V)-2-tert-butylphenoxides

Sharma N., Sharma M., Kumari M., Chaudhry S. C.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 9

1565-1573

EN

The niobium(V)-2-butylphenoxides of composition [NbCl(OC6H4C(CH3)3-2)4] (I) and [Nb(OC6H4C(CH3)3-2)5] (II) have been synthesized by the reaction of NbCl5 with Me3SiOC6H4C(CH3)3-2 in CCl4 and have been characterized by elemental analyses, molar conductance, molecular weight determination, IR, 1H and 13C NMR and UV-VIS spectral studies. The molecular model calculations were performed to visualize the probable geometry acquired by the complexes. Based upon spectral and molecular modelling dynamics, a square-pyramidal geometry around niobium in complexes has been proposed. Thermal behaviour of the complexes has been studied by TG, DTA and DSC techniques. The reactions of [NbCl(OC6H4C(CH3)3-2)4] (I) with chloride ion accecptors – FeCl3 and PCl5 have yielded complexes of composition [Nb(OC6H4C(CH3)3-2)4]×[FeCl4] and [Nb(OC6H4C(CH3)3-2)4]×[PCl6] authenticated by physicochemical and IR data.

14

Synthesis, Characterization and Reactivity of Bis(4-tert-butylphenolato)dichlorotin(IV)

Chaudhry S. C., Bandna K., Bhatt S. S., Sharma N.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 9

1537-1545

EN

The bis(4-tert-butylphenolato)dichlorotin(IV) complex of composition SnCl2(OC6H4But-4)2 (1) has been synthesized by the reaction of tin tetrachloride with bimolar amount of 4-t-butylphenol in benzene under reflux and characterized by elemental analyses, molar conductance measurements, molecular weight determination, IR, 1H, 13C NMR and FAB mass spectral techniques. Thermal behaviour of the complex has been investigated using TG-DTA technique. Lewis acid character of (1) has been explored by isolating its addition compounds with some nitrogeneous bases viz. diethylamine, triethylamine, imidazole, benzimidazole (L); 2,2'-bipyridyl, and 1,10-phenanthroline (B) of composition, SnCl2(OC6H4But-4)2×2L and SnCl2(OC6H4But-4)2×B, characterized by physicochemical and IR spectral studies.

15

Synthesis, Characterization and Antifungal Activity of Mono-Oxovanadium(V) Complexes of 4-Phenylphenol

Sharma N., Thakur M., Sagar A., Chaudhry S. C.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 11

1859-1870

EN

New mono-oxovanadium(V) complexes of composition VOCl3-n(OC6H4-C6H5-4)n (where n = 1 to 3) have been synthesized in quantitative yields by the in-situ reaction of VOCl3 with trimethylsilyl derivative of 4-phenylphenol and characterized by elemental analyses, molar conductance measurements and IR, 1H NMR and mass spectral methods. The reactions of complexes with a variety of nitrogenous bases viz. imidazole and benzimidazole (L); 2,2'-bipyridyl and 1,10-phenanthroline (B) yielded adducts of composition VOCl3-n(OC6H4-C6H5-4)n×2L and VOCl3-n(OC6H4-C6H5-4)n×B, proved by analytical and IR spectral data. The molecular model calculations through optimum energy minimization for the perspective geometry of the complexes have also been computed. The ligand, 4-phenylphenol, as well as the synthesized complexes show growth inhibitory activity against pathogenic fungus Fusarium oxysporum.

16

Synthesis, Characterization and Antibacterial Activity of Triorganotin(IV) Complexes of 4-Methylphenol

Sharma N., Kumar V., Thakur M., Kumari M., Chaudhry S. C.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2051--2065

EN

The triorganotin(IV) com plex of com po si tion Ph3Sn(OArMe-4) has been synthesized in good yields by the reaction of Ph3SnCl with Me3SiOArMe-4/NaOArMe-4, while complexes of composition Me3Sn(OArMe-4) and n-Bu3Sn(OArMe-4) (where -OArMe-4 = -OC6H4CH3-4) have been obtained from the reaction of Me3SnCl and n-Bu3SnCl with 4-methylphenol in the presence of triethylamine in carbon tetrachloride. The complexes have been characterized by elemental analyses, molar conductance measurements, molecular weight determin tion and IR, 1H and 13C NMR and mass spectral studies. Thermal behaviour of the complexes has been studied by TG and DTA techniques. The organotin(IV) complexes have also been screened for their antibacterial properties and are found to exhibit appreciable activity. The reactions of the complexes with 2-, 3-, 4-cyanopyridines yielded 1:1 adducts as confirmed by physicochemical and IR spectral data.

17

Bivalent Tin(II)-4-methoxyphenoxide: Synthesis, Characterization, Reactivity and Antifungal Activity

Chaudhry S. C., Bandna K., Bhatt S. S., Sharma N., Sagar A.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 3

391-400

EN

Bivalent tin(II)-4-methoxyphenoxide of composition Sn(OC6H4OMe-4)2 (1) has been synthesized from the reaction of SnCl2 with bimolar amounts of 4-methoxyphenol and diethylamine in tetrahydrofuran and characterized by elemental analysis, molar conductance measurement and IR spectral studies. Thermal behaviour of the complex has been studied by TGA-DTA techniques. The reactivity of (1) with HgCl2 has been investigated using potentiometric and cyclic voltammetric technique. Conductometric titration of complex (1) with sodium salt of 4-methoxyphenol suggests the formation of double phenoxide of composition Na2[Sn(OC6H4OMe-4)4]. Addition compounds of composition Sn(OC6H4OMe-4)2ź2L and Sn(OC6H4OMe-4)2źB (L = diethylamine and pyridine; B= l,10-phenanthroline and 2,2'-bipyridyl) have also been prepared and characterized by physicochemical and IR spectral studies. The complex (1) has also been screened for its antifungal activity.

18

Effects of viscosity and stiffness on wave propagation in micropolar viscoelastic media

Kumar R., Sharma N.

International Journal of Applied Mechanics and Engineering

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2009

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Vol. 14, no 2

415-431

EN

The problem of a reflection and transmission of plane waves at an imperfect interface between two homogeneous, isotropic micropolar viscoelastic half-spaces of different properties is studied. The expressions for the reflection and transmission coefficients which are the ratios of the amplitude of reflected and transmitted waves to the angle of incident wave are obtained and deduced for the normal force stiffness, transverse force stiffness, transverse couple stiffness and perfect bonding. Viscous and stiffness effects on these amplitude ratios with angle of incidence have been shown graphically. Some special cases of interest have been deduced from the present investigation.