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Kadomtsev–Petviashvili(KP) Burgers Equation in Dusty negative Ion Plasmas:Evolution of Dust-Ion Acoustic Shocks

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Communications in Theoretical Physics 2014年第12期61卷 875-880页

作者： a.n.dev J.Sarma M.K.Deka A.P.Misra n.C.Adhikary Department of Science and Humanities College of Science and Technology RUB Bhutan Department of Mathematics R.G.Baruah College Guwahati-781025 Assam India Centre of Plasma Physics Tepesia Sonapur Kamrup Assam India Department of Mathematics Siksha Bhavana Visva-Bharati University Santiniketan-731 235 India Physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim BoragaonGarchuk Guwahati – 781035 Assam India

We study the nonlinear propagation of dust-ion acoustic(DIA) shock waves in an un-magnetized dusty plasma which consists of electrons, both positive and negative ions and negatively charged immobile dust grains. Starting from a set of hydrodynamic equations with the ion thermal pressures and ion kinematic viscosities included, and using a standard reductive perturbation method, the Kadomtsev–Petviashivili–Burgers(K-P-Burgers) equation is derived, which governs the evolution of DIA shocks. A stationary solution of the K-P-Burgers equation is obtained and its properties are analysed with different plasma number densities, ion temperatures and masses. It is shown that a transition from shocks with negative potential to positive one occurs depending on the negative ion concentration in the plasma and the obliqueness of propagation of DIA waves.

关键词： dusty plasmas Shock wave reductive perturbation technique K-P burgers equation

Lower order three-dimensional Burgers equation having non-Maxwellian ions in dusty plasmas

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Chinese Physics B 2017年第2期26卷 327-333页

作者： Apul n dev Center for Applied Mathematics Siksha ‘O＇ Anusandhan University Khandagiri Bhubaneswar-751030 Odisha India

The dust acoustic（DA） shock wave with dust charge fluctuations, non-Maxwellian ions, and non-isothermal electrons is studied theoretically. The perturbation technique is employed to derive the lower order three-dimensional（3D） Burgers equation, and shock wave solution is explored by the tan-hyperbolic method. The effects of flat trapped and trapped electron distributions in the presence of Maxwellian and non-Maxwellian ions on characteristics shock waves are observed. The temperature ratio of non-Maxwellian ion temperature and non-isothermal electron temperature is found to play an important role in forming the shock-like structure.

关键词： dust acoustics shock wave dust charge fluctutations non-isothermal electrons tan-hyperbolic method

Predicting uniaxial compressive strength of tuff after accelerated freeze-thaw testing: Comparative analysis of regression models and artificial neural networks

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Journal of Mountain Science 2024年第10期21卷 3521-3535页

作者： Ogün Ozan VAROL Department of Mining Engineering Faculty of EngineeringVan Yuzuncu Yil UniversityVan 65080Türkiye

Ignimbrites have been widely used as building materials in many historical and touristic structures in the Kayseri region of Türkiye. Their diverse colours and textures make them a popular choice for modern construction as well. However, ignimbrites are particularly vulnerable to atmospheric conditions, such as freeze-thaw cycles, due to their high porosity, which is a result of their formation process. When water enters the pores of the ignimbrites, it can freeze during cold weather. As the water freezes and expands, it generates internal stress within the stone, causing micro-cracks to develop. Over time, repeated freeze-thaw (F-T) cycles lead to the growth of these micro-cracks into larger cracks, compromising the structural integrity of the ignimbrites and eventually making them unsuitable for use as building materials. The determination of the long-term F-T performance of ignimbrites can be established after long F-T experimental processes. Determining the long-term F-T performance of ignimbrites typically requires extensive experimental testing over prolonged freeze-thaw cycles. To streamline this process, developing accurate predictive equations becomes crucial. In this study, such equations were formulated using classical regression analyses and artificial neural networks (Ann) based on data obtained from these experiments, allowing for the prediction of the F-T performance of ignimbrites and other similar building stones without the need for lengthy testing. In this study, uniaxial compressive strength, ultrasonic propagation velocity, apparent porosity and mass loss of ignimbrites after long-term F-T were determined. Following the F-T cycles, the disintegration rate was evaluated using decay function approaches, while uniaxial compressive strength (UCS) values were predicted with minimal input parameters through both regression and Ann analyses. The Ann and regression models created for this purpose were first started with a single input value and then dev

关键词： Ignimbrite Uniaxial compressive strength Freeze-thaw Decay function Regression Artificial neural network

K-P-Burgers equation in negative ion-rich relativistic dusty plasma including the effect of kinematic viscosity

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Chinese Physics B 2016年第10期25卷 215-221页

作者： a.n.dev M K Deka J Sarma D Saikia n C Adhikary Department of Mathematics Siksha ‘O' Anusandhan University Department of Applied Sciences Institute of Science and Technology Gauhati University Department of Mathematics R G Baruah College Physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan Path Paschim Boragaon

The stationary solution is obtained for the K–P–Burgers equation that describes the nonlinear propagations of dust ion acoustic waves in a multi-component, collisionless, un-magnetized relativistic dusty plasma consisting of electrons, positive and negative ions in the presence of charged massive dust grains. Here, the Kadomtsev–Petviashvili(K–P) equation, threedimensional(3D) Burgers equation, and K–P–Burgers equations are derived by using the reductive perturbation method including the effects of viscosity of plasma fluid, thermal energy, ion density, and ion temperature on the structure of a dust ion acoustic shock wave(DIASW). The K–P equation predictes the existences of stationary small amplitude solitary wave,whereas the K–P–Burgers equation in the weakly relativistic regime describes the evolution of shock-like structures in such a multi-ion dusty plasma.

关键词： K–P–Burgers equation negative ion relativistic plasma reductive perturbation method

Characteristics of dust acoustic waves in dissipative dusty plasma in the presence of trapped electrons

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Plasma Science and Technology 2017年第5期19卷 21-28页

作者： Ranjit K KALITA Manoj K DEKA Apul n dev Jnanjyoti SARMA Department of Mathematics Morigaon College Morigaon-782105 Assam India Department of Applied Sciences Institute of Science and Technology Gauhati University Guwahati-781014 Assam India Center for Applied Mathematics Siksha 'O' Anusandhan University Bhubaneswar-751030 OdishaIndia Department of Mathematics R. G. Baruah College Guwahati-781025 Assam India

The formation and propagation of nonlinear dust acoustic waves（DAWs） as solitary and solitary/shock waves in an unmagnetized, homogeneous, dissipative and collisionless dusty plasma comprising negatively charged micron sized dust grains in the presence of free and trapped electrons with singly charged non-thermal positive ions is discussed in detail. The evolution characteristics of the solitary and shock waves are studied by deriving a modified Korteweg–de Vries–Burgers（mKdV–Burgers） equation using the reductive perturbation method. The mKdV–Burgers equation is solved considering the presence（absence） of dissipation. In the absence of dissipation the system admits a solitary wave solution, whereas in the presence of dissipation the system admits shock waves（both monotonic and oscillatory） as well as a combination of solitary and shock wave solutions. Standard methods of solving the evolution equation of shock（solitary） waves are used. The results are discussed numerically using standard values of plasma parameters. The findings may be useful for better understanding of formation and propagation of waves in astrophysical plasma.

关键词： dust acoustic shock wave trapped electrons dissipation

Dust Acoustic Compressive Waves in a Warm Dusty Plasma Having non-Thermal Ions and non-Isothermal Electrons

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Plasma Science and Technology 2015年第9期17卷 721-727页

作者： Apul n.dev Manoj K.DEKA Rajesh SUBEDI Jnanjyoti SARMA Department of Science and Humanities College of Science and Technology Department of Applied Sciences Institute of Science and TechnologyGauhati University Department of Mathematics R.G.Baruah College

In this article an investigation is presented on the properties of dust acoustic（DA）compressive solitary wave propagation in an adiabatic dusty plasma,including the effect of nonthermal positive and negative ions and non-isothermal *** reductive perturbation method has been employed to derive the lower degree modified Kadomtsev-Petviashivili（mK-P）,3D Schamel-Korteweg-de-Vries equation or modified Kadomtsev-Petviashivili（mK-P） equations for dust acoustic solitary waves in a homogeneous,unmagnetized and collisionless plasma whose constituents are non-isothermal electrons,singly charged positive and negative non-thermal ions and massive charged dust *** stationary analytical solutions of the lower degree mK-P and mK-P equations are numerically analyzed,where the effect of various dusty plasma constituents on DA solitary wave propagation is taken into *** is observed that both the ions in dusty plasma play a key role in the formation of DA compressive solitary waves,and also the ion concentration and non-isothermal electrons control the transformation of the compressive potentials of the waves.

关键词： dusty plasma reductive perturbation method non-isothermal ions compressive solitary wave

Dust Acoustic Shock Waves with non-Thermal and Vortex-Like Ions in Dusty Plasma

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Plasma Science and Technology 2015年第4期17卷 268-275页

作者： Apul n.dev Jnanjyoti SARMA Manoj K.DEKA nirab C.ADHIKARY Department of Science and Humanities College of Science and Technology RUB Bhutan Department of Mathematics R. G. Baruah College Guwahati-781025 Assam India Centre of Plasma Physics Tepesia Sonapur Assam India Physical Science Divison Institute of Advanced Study in Science and Technology Vigyan Path Garchuk Guwahati-781035 Assam India

A rigorous investigation is presented on the propagation characteristics of non-linear dust acoustic（DA）waves in an unmagnetized dusty plasma system containing non-thermal and vortex-like ions and Maxwellian electrons under the effect of a fluctuating charged dust *** three-dimensional（3D）Burgers＇equation and a new form of a lower degree modified 3D Burgers＇equation with their analytical solutions are derived to study the features of shock waves in such *** effect of the population of non-thermal ions,the vortex-like ion parameter as well as the temperature ratios of ions and electrons on the evolution of shock waves in the presence of dust charge fluctuation is *** theoretical investigation might be effectively utilized to unveil the nature of many astrophysical plasma environments（Saturn＇s spokes etc.）where such plasmas are reported to have existed.

关键词： dusty plasma reductive perturbation method 3D Burgers' equation modified 3D Burgers' equation tan-hyperbolic method

Trend in Observed and Projected Maximum and Minimum Temperature over n-W Himalayan Basin

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Journal of Mountain Science 2015年第2期12卷 417-433页

作者： Dharmaveer SInGH Sanjay K JAIn Rajan dev GUPTA GIS Cell Motilal Nehru National Institute of Technology Allahabad Water Resources Systems Division National Institute of Hydrology Department of Civil Engineering Motilal Nehru National Institute of Technology Allahabad

Recently, study in past trends of climate variables gained significant consideration because of its contribution in adaptions and mitigation strategies for potential future changes in climate, primarily in the area of water resource management. Future interannual and inter-seasonal variations in maximum and minimum temperature may bring significant changes in hydrological systems and affect regional water resources. The present study has been performed to observe past(1970-2010) as well as future(2011-2100)spatial and temporal variability in temperature(maximum and minimum) over selected stations of Sutlej basin located in north-Western Himalayan region in India. The generation of future time series of temperature data at different stations is done using statistical downscaling technique. The nonparametric test methods, modified Mann-Kendall test and Cumulative Sum chart are used for detecting monotonic trend and sequential shift in time series of maximum and minimum temperature. Sen's slope estimator test is used to detect the magnitude of change over a period of time on annual and seasonal basis. The cooling experienced in annual TMax and TMin at Kasol in past(1970-2010) would be replaced by warming in future as increasing trends are detected in TMax during 2020 s and 2050 s and in TMin during 2020 s, 2050 s and 2080 s under A1 B and A2 scenarios. Similar results of warming are also predicted at Sunnifor annual TMin in future under both scenarios which witnessed cooling during 1970-2010. The rise in TMin at Rampur is predicted to be continued in future as increasing trends are obtained under both the scenarios. Seasonal trend analysis reveals large variability in trends of TMax and TMin over these stations for the future periods.

关键词： Statistical downscaling model Canadian Coupled Global Climate Model Temperature MannKendall test Sen’s slope estimator

Biotemplate Assisted nano Titania and Its Environmental Performance

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Journal of Minerals and Materials Characterization and Engineering 2020年第6期8卷 459-471页

作者： n. Saikumari S. Monish dev S. Avinaash dev Science and Humanities RMK College of Engineering and Technology Chennai India Anna University Chennai India RMKCET Chennai India

Environmental sustainability apart from spoken at different levels needs to investigate the management of industrial activities in terms of eco-friendliness. It is well known that effluents from various industries bec... 详细信息

Environmental sustainability apart from spoken at different levels needn>sn>n> to investigate the management of industrial activities in terms of econ>n>n>-n>n>friendliness. It is well known that effluents from various industries become a major source of environmental degradation in particular water pollution. Thus water analysis report turns to be more significant, to determine the quality and standard of life maintained in a typical ecosystem. This study includes the analysis of physico-chemical factors of raw as well as treated water samples from Korattur Lake employing nano sized adsorbents like titania with tuned structural and morphological properties through organic plant extract. The XRD analysis, BET analysis, DRS-UV analysis, SEM and TEM analysis have been carried out and reported. The marked influence of leaf extract as a template is reflected in reduced crystallite size (12.4 nm) with maximum surface area 105 m2n>n style="font-family:Verdana;">/g along with bathochromic shift of absorption edge. The usual indicators of contamination level at a given source namely Biological Oxygen Demand (BOD-85%), Chemical Oxygen De

关键词： Sustainability Ecosystem Pollution nano Titania Plant Extract