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Study of anisotropic variation of cosmic rays intensity with solar activity

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Natural Science 2011年第2期3卷 101-103页

作者： chandra mani tiwari Devendra Sharma Lalji tiwari Ajay Kumar Saxena Dadan Prasad tiwari 不详

The annual average values of amplitudes and phases of first two harmonics of cosmic ray anisotropy have been derived by using the harmonic analysis technique for the period 1989 to 2004, which covers mostly the major period of solar cycles 22 and 23. In this paper we have taken the pressure corrected hourly data for Kiel neutron monitor station (cut off rigidity ≈ 2.29 GV) to derive the harmonic component of cosmic ray daily variation and compared with the data of Halekala neutron monitor (cut off rigidity ≈ 13.2 GV) for the period 1991 to 2004. From the analysis it has been concluded that the diurnal amplitude and phase of daily variation of cosmic rays have been found to be correlated with solar activity. However, the semi-diurnal amplitude and phase are inversely correlated with solar activity for both the stations.

关键词： Cosmic Ray Anisotropic Variation Solar Parameter

Effect of Coronal Mass Ejection on Earth’s Magnetic Field during Ascending Phase of Solar Cycles 23-24

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International Journal of Astronomy and Astrophysics 2017年第3期7卷 213-220页

作者： Bharti Nigam Prithvi Raj Singh Pramod Kumar Chamadia Ajay Kumar Saxena chandra mani tiwari Govt. Autonamous P. G. Science College Satna India Department of Physics Awadhesh Pratap Singh University Rewa India

We have studied the width and speed of coronal mass ejections (CMEs) and geomagnetic disturbance storm time (Dst) Index during ascending phase of solar cycles 23 and 24. We have classified total CMEs according to angular width and speed for the ascending period 1996-2002 and 2008-2014. We have found that the width of 62% CMEs is narrow, and 3% are Halo for the solar cycle 23 and 73% CMEs are narrow, and 2% CMEs are Halo for the solar cycle 24. The speed distribution of 65% CMEs has speed ≤ 500 km/sec and 4% CMEs has speed > 1000 km/sec for solar cycle 23 and 84% CMEs has speed ≤ 500 km/sec and 1% CMEs has speed > 1000 km/sec in cycle 24. The relationship between width and speed is more pronounced for fast ejecta (>1000 km/sec.), while slower ejecta shows more astronomically immense scatter. We have reported that the correlation between Dst and CMEs for ascending phase of solar cycle 24 is less than as compare to ascending phase of solar cycle 23.

关键词： CME Dst SSN

Cosmic Ray Associated with Coronal Index and Solar Flare Index during Solar Cycle 22 - 23

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International Journal of Astronomy and Astrophysics 2017年第3期7卷 162-173页

作者： Prithvi Raj Singh Shabir Ahmad A. C. Pandey Ajay Kumar Saxena chandra mani tiwari A. P. Mishra Department of Physics A.P.S. University Rewa M.P. India

We study the relation between monthly average counting rates of the cosmic ray intensity (CRI) observed at Moscow Neutron Monitoring Station, solar flare index (SFI) and coronal index during the solar cycles 22 and 23, for the period 1986-2008. The long-term behaviour of various solar activity parameters: sunspot numbers (SSN), solar flare index (Hα flare index), coronal index (CI) in relation to the duration of solar cycles 22 and 23 is examined. We find that the correlation coefficient of CRI with the coronal index as well as Hα flare index is relatively large anti-correlation during solar cycle 22. However, the monthly mean values of sunspot number, Hα flare index, and coronal index are well positively correlated with each other. We have analyzed the statistical analysis of the above parameters using of linear model and second order polynomial fits model.

关键词： Solar Activity Sunspot Number Coronal Index Solar Flare Index Cosmic Ray Intensity

An efficient algorithm to clip a 2D-polygon against a rectangular clip window

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Applied Mathematics(A Journal of Chinese Universities) 2022年第1期37卷 147-158页

作者： Sushil chandra Dimri Umesh Kumar tiwari Mangey Ram Department of Computer Science and Engineering Graphic Era(Deemed to be University)DehradunUttarakhandIndia

Polygon clipping is of great importance in computer *** of the popular algorithms to clip a polygon is Cohan–Sutherland Hodgeman algorithm which is based on line ***–Sutherland Hodgeman algorithm clips the polygon against the given rectangular clip window with the help of line clipping ***–Sutherland algorithm requires traversing the polygon in anti clockwise direction(positive orientation).In this work we propose an efficient polygon clipping algorithm against a rectangular clip *** algorithm uses parametric representation of polygon *** the concept of point clipping,we can find required intersection points of edges of polygon with clip window *** suited numerical illustrations are used to explain the proposed polygon clipping *** proposed algorithm is computationally less expensive and comprehensive.

关键词： point clipping polygon clipping clip window line segment computational complexity

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Exploring the potential of artificial intelligence techniques in prediction of the removal efficiency of vortex tube silt ejector

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International Journal of Sediment Research 2023年第4期38卷 615-627页

作者： Sanjeev Kumar chandra Shekhar Prasad Ojha Nand Kumar tiwari Subodh Ranjan Department of Civil Engineering Indian Institute of Technology Department of Civil Engineering National Institute of Technology

A vortex tube silt ejector is a curative hydraulic structure used to remove sediment deposits from canals and is recognized as one of the most efficient substitutes for physically removing canal sediment. The spatially varied flow in the channel and the rotational flow behavior in the tube make the silt removal process complex. It is even harder to accurately predict the silt removal efficiency by traditional models accurately. However, artificial intelligence(AI) and machine learning approaches have emerged as robust substitutes for studying complex processes. Therefore, this research makes use of AI approaches; support vector machine(SVM), random forest(RF), random tree(RT), and multivariate adaptive regression spline(MARS) to compute the vortex tube silt ejection efficiency using the laboratory data sets. The outcomes of the artificial intelligence(AI)-based techniques also were compared with traditional models. It was found that the RT model(root mean square error, RMSE = 2.165, Nash Sutcliffe efficiency, NSE = 0.98) outperforms the other applied approaches which had relatively more significant result errors. The sensitivity analysis of the process depicts the extraction ratio as the key parameter in the computation of vortex tube silt ejector removal efficiency. The findings of the AI-based approaches discussed in the current study might be helpful for hydraulic engineers as well as researchers in the assessment of the removal efficiency of vortex tube silt ejectors.

关键词： Vortex tube silt ejector Support vector machine Random forest Random tree Multivariate adaptive regression spline

Further contribution to the Neogene petrified wood forest of Mizoram, India

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科学通报 2013年第S1期58卷 104-110页

作者： MEHROTRA Rakesh chandra tiwari R P SRIVASTAVA Gaurav SHUKLA Anumeha Birbal Sahni Institute of Palaeobotany Department of Geology Mizoram University

Mizoram, a state situated in the northeast corner of India, is very rich in fossil woods belonging to the Tipam Group(Late Miocene-Early Pliocene in age). Four new fossil woods, namely Swintonioxylon hailakandiense Prakash & Tripathi, Bombacacioxylon tertiarum Mehrotra et al., gen. et sp. nov., Dipterocarpoxylon jammuense Guleria et al. and Bischofia palaeojavanica Awasthi are described from there. They resemble the modern taxa, namely Swintonia Griff.(Anacardiaceae), Dipterocarpus C.F. Gaertn.(Dipterocarpaceae), Bischofia Blume(Euphorbiaceae) and the taxa of the family Bombacaceae. The distribution of the modern equivalents of the present and previously described taxa indicates the existence of warm and humid climate in Mizoram during the depositional time.

关键词： fossil wood Tipam Group angiosperms northeast India palaeoclimate

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Heterologous expression of Lolium perenne antifreeze protein confers chilling tolerance in tomato

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Journal of Integrative Agriculture 2018年第5期17卷 1128-1136页

作者： Srinivasan Balamurugan Jayan Susan Ann Inchakalody P Varghese Shanmugaraj Bala Murugan mani chandra Harish Sarma Rajeev Kumar Ramalingam Sathishkumar Plant Genetic Engineering Laboratory Department of BiotechnologyBharathiar University

Antifreeze proteins（AFP） are produced by certain plants, animals, fungi and bacteria that enable them to survive upon extremely low temperature. Perennial rye grass, Lolium perenne, was reported to possess AFP which protects them from cold environments. In the present investigation, we isolated AFP gene from L. perenne and expressed it in tomato plants to elucidate its role upon chilling stress. The T1 transgenic tomato lines were selected and subjected to molecular, biochemical and physiological analyses. Stable integration and transcription of Lp AFP in transgenic tomato plants was confirmed by Southern blot hybridization and RT-PCR, respectively. Physiological analyses under chilling conditions showed that the chilling stress induced physiological damage in wild type（WT） plants, while the transgenic plants remained healthy. Total sugar content increased gradually in both WT and transgenic plants throughout the chilling treatment. Interestingly, transgenic plants exhibited remarkable alterations in terms of relative water content（RWC） and electrolyte leakage index（ELI） than those of WT. RWC increased significantly by 3-fold and the electrolyte leakage was reduced by 2.6-fold in transgenic plants comparing with WT. Overall, this report proved that Lp AFP gene confers chilling tolerance in transgenic tomato plants and it could be a potential candidate to extrapolate the chilling tolerance on other chilling-sensitive food crops.

关键词： Lolium perenne antifreeze protein chilling tolerance genetic transformation transgenic tomato

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Predicting morbidity and mortality in acute pancreatitis in an Indian population:a comparative study of the BISAP score,Ranson’s score and CT severity index

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Gastroenterology Report 2016年第3期4卷 216-220,I0002页

作者： Jitin Yadav Sanjay Kumar Yadav Satish Kumar Ranjan George Baxla Dipendra Kumar Sinha Pankaj Bodra Ram chandra Besra Babu mani Baski Om Prakash Abhinav Anand Department of General Surgery Rajendra Institute of Medical SciencesRanchiJharkhandIndia

Objective:Our aim was to prospectively evaluate the accuracy of the bedside index for severity in acute pancreatitis(BISAP)score in predicting mortality,as well as intermediate markers of severity,in a tertiary care centre in east central India,which caters mostly for an economically underprivileged ***:A total of 119 consecutive cases with acute pancreatitis were admitted to our institution between November 2012 and October *** scores were calculated for all cases,within 24 hours of ***’s score and computed tomography severity index(CTSI)were also *** respective abilities of the three scoring systems to predict mortality was evaluated using trend and discrimination *** optimal cut-off score for mortality from the receiver operating characteristics(ROC)curve was used to evaluate the development of persistent organ failure and pancreatic necrosis(PNec).Results:Of the 119 cases,42(35.2%)developed organ failure and were classified as severe acute pancreatitis(SAP),47(39.5%)developed PNec,and 12(10.1%)*** area under the curve(AUC)results for BISAP score in predicting SAP,PNec,and mortality were 0.962,0.934 and 0.846,***’s score showed a slightly lower accuracy for predicting SAP(AUC 0.956)and mortality(AUC 0.841).CTSI was the most accurate in predicting PNec,with an AUC of *** sensitivity and specificity of BISAP score,with a cut-off of≥3 in predicting mortality,were 100%and 69.2%,***:The BISAP score represents a simple way of identifying,within 24 hours of presentation,patients at greater risk of dying and the development of intermediate markers of *** risk stratification method can be utilized to improve clinical care and facilitate enrolment in clinical trials.

关键词： acute pancreatitis mortality bedside index for severity in acute pancreatitis(BISAP) Ranson’s score computed tomography severity index(CTSI)

High-Order FEM Formulation for 3-D Slope Instability

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Applied Mathematics 2013年第5期4卷 8-17页

作者： tiwari Ram chandra Bhandary Netra Prakash Yatabe Ryuichi Geo-Disaster Laboratory Graduate School of Science and Engineering Ehime University Matsuyama Japan Graduate School of Science and Engineering Ehime University Matsuyama Japan

High-order finite element method (FEM) formulation also referred to as spectral element method (SEM) formulation is currently implemented in this paper for 3-dimensional (3-D) elasto-plastic problems in stability assessment of large- scale slopes (vegetated and barren slopes) in different instability conditions such as seismic and saturation. We have reviewed the SEM formulation, and have sought its applicability for vegetated slopes. Utilizing p (high-order polynomial degree or spectral degrees) and h (mesh operation for quality meshing in required elemental budgets) refining techniques in the existing FEM, the complexity of problem domain can be well addressed in greater numerical stability. Unlike the existing FEM formulation, this high-order FEM employs the same integration and interpolation points to achieve a progressive response of the instability, which drastically reduces the computational costs (formation of diagonalized mass matrix) and offers significant benefits to slope instability computations for serial and parallel implementations. With this formulation, we have achieved the following three qualities in slope instability modeling: 1) geometric flexibility of the finite elements, 2) high computational efficiency, and 3) reliable spectral accuracy. A sample problem has also been presented in this paper, which has accommodated all aforesaid numerical qualities.

关键词： Finite Element Method Spectral Element Method Slope Instability Vegetated and Barren Slopes Parallel Algorithm