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Modeling the effect of time delay in implementation of mitigation policies on the control of atmospheric greenhouse gases

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International Journal of Biomathematics 2023年第8期16卷 75-108页

作者： Alok kumar verma Maitri verma Department of Mathematics School of Physical and Decision Science Babasaheb Bhimrao Ambedkar University Lucknow India

Mitigation of the enhanced greenhouse gas(GHG)concentrations in the Earth's atmosphere is imperative to meet the climate change mitigation *** of many countries are developing and implementing various mitigation strategies to reduce their GHG ***,a time delay between the formulation and implementation of these mitigation policies can affect their effectiveness in controlling greenhouse gas levels in the *** work presents a nonlinear mathematical model to investigate the effect of application of mitigation strategies and the delay involved in their implementation over the reduction of atmospheric greenhouse *** model formulation,it is assumed that the mitigation strategies work two-fold;first they reduce the GHG emission rate from the anthropogenic source and second they increase the removal rate of greenhouse gas from the atmosphere.A comprehensive stability analysis of the proposed model system is made to examine its long-term *** model analysis shows that an increase in the implementation rate of mitigation strategies and their efficiencies to cut down the GHG emission rate from point sources and increase the GHG uptake rate lead to reduction in equilibrium GHG *** is found that a long delay in the execution of mitigation policies can destabilize the system dynamics and leads to the generation of periodic *** expression for the threshold value of the delay parameter at which periodic oscillations arise via Hopf-bifurcation is *** stability and direction of bifurcating periodic solutions are discussed.A sensitivity analysis is performed to investigate the effect of changes in key parameters over system dynamics.

关键词： Mathematical model greenhouse gases global warming mitigation strategies time delay Hopf-bifurcation

Polyaxial strength criterion and closed-form solution for squeezing rock conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 507-515页

作者： Rupesh kumar verma Sarvesh Chandra Department of Civil Engineering Indian Institute of Technology KanpurKanpur208016India

In this paper,a nonlinear strength criterion is proposed using the average of intermediate(σ2)and minor(σ3)principal stresses in place of σ3 in Ramamurthy(1994)’s strength *** proposed criterion has the main advantages of negligible variation of strength parameters with confining stress and ability to link with conventional strength ***,a new closed-form solution based on the proposed criterion is derived and validated for Chhibro Khodri ***,analytical solutions including Singh’s elastoplastic theory,Scussel’s approach,and closed-form solutions based on conventional and modified Ramamurthy(2007)criteria are compared with the results of proposed *** is shown that the in situ squeezing pressure predictions made by the proposed approach are more ***,a parametric study of the present analytical solution is carried out,which displays explicit dependency of tunnel stability on internal support pressure and tunnel *** influence of tunnel geometry is observed to be dependent on the applied support pressure.

关键词： Intermediate principal stress Squeezing pressure Closed-form solution Polyaxial strength criterion

Helicobacter pylori isolated from gastric juice have higher pathogenic potential than biopsy isolates

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Genes & Diseases 2024年第1期11卷 34-37页

作者： Budhadev Baral Dharmendra Kashyap Nidhi Varshney Tarun prakash verma Ajay kumar Jain Debi Chatterji Vinod kumar Amit Mishra Awanish kumar Hem Chandra Jha Infection Bioengineering Group Department of Biosciences and Biomedical EngineeringIndian Institute of Technology IndoreSimrolIndoreMadhya Pradesh 453552India Choithram Hospital and Research Center IndoreMadhya Pradesh452014India Department of Metallurgy Engineering and Materials Science Indian Institute of Technology IndoreSimrolIndoreMadhya Pradesh 453552India Department of Bioscience&Bioengineering Indian Institute of Technology JodhpurNH 65 Nagaur RoadJodhpur DistrictKarwarRajasthan 342037India Department of Biotechnology National Institute of Technology RaipurGE RoadRaipurChhattisgarh 492010India

Persistent gastritis induced by Helicobacter pylori(***)is the strongest known risk factor for gastric cancer(GC).*** is prevalent in about 50%world's population,while it causes cancer in less than 2%of exposed individuals.1 Our studies found that *** infection can induce oncogenic properties in AGS cells by deregulating multiple factors associated with the cell cycle,apoptosis,and other important events associated with cancer progression.

关键词： H.pylori pylori Helicobacter

Impact of geomorphometric parameters on the occurrence and distribution of landslides in Yamuna River Basin,North-Western Himalaya,India

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Journal of Mountain Science 2022年第8期19卷 2374-2396页

作者： Ravi SHANKAR Gyan prakash SATYAM prakash kumar SINGH Nilesh kumar RAI Ranjit kumar PASWAN REED CSIR-Central Institute of Mining and Fuel ResearchDhanbad 826001India Department of Applied Geology Indian Institute of Technology(ISM)Dhanbad 826004India Department of Earth and Planetary Sciences University of AllahabadPrayagraj 211002Uttar PradeshIndia

The majority of landslides in the Indian Himalayas are triggered by rainfall and *** geology and geomorphology also play an important role and constitute the major predisposing factor controlling ***,active tectonics modify the landscape,impacting the occurrence and distribution of *** objective of this study is to investigate the role of some of the major predisposing factors to assess landslide patterns in the Yamuna River Basin as it is prone to recurrent landslide *** approach mainly deals with the application of geographical information system-based statistical analysis and quantifying frequency-area distribution of rainfalltriggered landslides for the years 2015 to *** analysis shows that the frequency of landslides is highest in the slope range 40°-70°and the mean landslide size is higher in the slope range 0°-20°and 30°-40°,remaining constant on further increase in slope *** study shows that some critical slope range controls both the frequency and size of *** were mostly restricted to south facing *** 91%of the landslide occur in the drainage density range of 1.2 to 2.1 km/km^(2) while landslides show very low occurrence in either lower(2.1)drainage *** distribution analysis of landslides depicts a distinct cutoff point but an indistinct rollover ***-sampling of small landslides can be a reasonable cause for *** other studies,the present data fits very well for medium and large landslides following an inverse power law with a scaling exponent *** 80% of landslides are smaller than the cutoff size and 20% larger than this *** geology and tectonics of Lesser Himalayas and Sivaliks offer favorable conditions for frequent *** such as Dehradun,Uttarkashi,Sirmaur,Shimla,and Solan are very prone to landslide activity owing to the presence of poorly consolidated sandstone,conglomerate,quartzites,phylli

关键词： Himalaya Geomorphometry Landslide Yamuna River Basin

Structural, Optical, and Ferroelectric Behaviors of Cu_(1-x)Li_xO(0≤x≤0.09) Nanostructures

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 306-312页

作者： prakash Chand Anurag Gaur Ashavani kumar Department of Physics National Institute of Technology Kurukshetra

We report structural, optical, and ferroelectric behaviors of lithium-doped copper oxide （CU1-xLixO with x = 0.0, 0.05, 0.07, and 0.09） nanostructures synthesized by hydrothermal method. The XRD pattern indicates the pure phase formation of CuO without any impurity, and the crystallite size is found to be increases for x = 0-0.07 and decreases for x = 0.09. FESEM analysis shows that the average size of Cul xLixO nanostructures increases with the increasing the Li-doping concentrations up to 7% and then decreases for 9% Li doping concentration. Moreover, Raman and photoluminescence spectrum also confirm the phase formation of CuO. A significant reduction in optical band gap is observed up to x = 0.07, and then band gap increases for x ~ 0.09 due to segregation of the impurities on the surface or grain boundaries, which may suppress the grain growth and results the enhancement in optical band gap. Moreover, a weak ferroelectricity is observed in CuO nanostructures for pure and 9% Li doping through polarization versus electric field （P- E）.

关键词： CuO nanostructure Optical properties PL and Raman spectroscopy

Positive solutions and stability of fuzzy Atangana–Baleanu variable fractional differential equation model for a novel coronavirus (COVID-19)

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第6期12卷 205-229页

作者： Pratibha verma Manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad Prayagraj 211004 Uttar PradeshIndia

This work provides a new fuzzy variable fractional COVID-19 model and uses a variablefractional operator, namely, the fuzzy variable Atangana–Baleanu fractional derivativesin the Caputo sense. Next, we explore the proposed fuzzy variable fractional COVID-19 model using the fixed point theory approach and determine the solution’s existenceand uniqueness conditions. We choose an appropriate mapping and with the help ofthe upper/lower solutions method. We prove the existence of a positive solution for theproposed fuzzy variable fractional COVID-19 model and also obtain the result on theexistence of a unique positive solution. Moreover, we discuss the generalized Hyers–Ulam stability and generalized Hyers–Ulam–Rassias stability. Further, we investigate theresults on maximum and minimum solutions for the fuzzy variable fractional COVID-19model.

关键词： Novel coronavirus(COVID-19) variable Atangana–Baleanu fractional derivative Mittag–Leffler kernel existence and uniqueness fixed point theorems Hyers–Ulam stability

An analytical solution of multi-dimensional space fractional diffusion equations with variable coefficients

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 229-255页

作者： Pratibha verma Manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad Prayagraj 211004 Uttar PradeshIndia

In this paper,we have considered the multi-dimensional space fractional diffusion equations with variable *** fractional operators(derivative/integral)are used based on the Caputo *** study provides an analytical approach to determine the analytical solution of the considered problems with the help of the two-step Adomian decomposition method(TSADM).Moreover,new results have been obtained for the existence and uniqueness of a solution by using the Banach contraction principle and a fixed point *** have extended the dimension of the space fractional diffusion equations with variable coefficients into ***,the generalized problems with two different types of the forcing term have been included demonstrating the applicability and high efficiency of the TSADM in comparison to other existing numerical *** diffusion coefficients do not require to satisfy any certain conditions/restrictions for using the *** are no restrictions imposed on the problems for diffusion coefficients,and a similar procedures of the TSADM has followed to the obtained analytical solution for the multi-dimensional space fractional diffusion equations with variable coefficients.

关键词： Caputo fractional operators space fractional diffusion equations Riesz derivative two-step Adomian decomposition method fixed point theorem

Remediation of nutrient-rich waters using the terrestrial plant, Pandanus amaryllifolius Roxb.

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Journal of Environmental Sciences 2014年第2期26卷 404-414页

作者： Ping HAN prakash kumar Bee-Lian Ong Singapore Delft Water Alliance National University of Singapore Department of Biological Sciences National University of Singapore

Effective control of eutrophication is generally established through the reduction of nutrient loading into waterways and water bodies. An economically viable and ecologically sustainable approach to nutrient pollution control could involve the integration of retention ponds, wetlands and greenways into water management systems. Plants not only play an invaluable role in the assimilation and removal of nutrients, but they also support fauna richness and can be aesthetically pleasing. Pandanus amaryllifolius, a tropical terrestrial plant, was found to establish well in hydrophytic conditions and was highly effective in remediating high nutrient levels in an aquatic environment showing 100% removal of NO^-N up to 200 mg/L in 14 days. Phosphate uptake by the plant was less efficient with 64% of the PO4-P removed at the maximum concentration of 100 mg/L at the end of 6 weeks. With its high NO^-N and PO43--P removal efficiency, P. amaryllifolius depleted the nutrient-rich media and markedly contained the natural colonization of algae. The impediment of algal growth led to improvements in the water quality with significant decreases in turbidity, pH and electrical conductivity. In addition, the plants did not show stress symptoms when grown in high nutrient levels as shown by the changes in their biomass, total soluble proteins and chlorophyll accumulation as well as photochemical efficiency. Thus, P. amaryUifolius is a potential candidate for the mitigation of nutrient pollution in phytoremediation systems in the tropics as the plant requires low maintenance, is tolerant to the natural variability of weather conditions and fluctuating hydro-periods, and exhibit good nutrient removal capabilities.

关键词： chlorophyll fluorescence nitrate and phosphate removal Pandanus amaryllifolius water quality

An analytical solution with existence and uniqueness conditions for fractional integro-differential equations

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第5期11卷 147-169页

作者： Pratibha verma Manoj kumar Department of Mathematics Motilal Nehru National Institute of Technology AllahabadPrayagraj-211004Uttar PradeshIndia

This study aims to apply the two-step Adomian decomposition method(TSADM)to find an analytical solution of integro-differential equations for fractional order without discretization/approximation with less number of iterations and reduce the computational ***,we have established the results for the existence and uniqueness of a solution with the help of some fixed point theorems and the Banach contraction ***,the method is demonstrated on different test examples arising in real life *** is concluded that the TSADM provides exact solution of the fractional integro-differential equations in one *** the same time,the other existing methods furnish an approximate solution and require lots of computation to solve the problem applying discretization/approximation on fractional operators.

关键词： Caputo fractional derivative two-step Adomian decomposition method integro-differential equation fixed point theorem