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Variations in Solar Cycles 22, 23 &24 and Their Effect on Earth’s Climate

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International Journal of Astronomy and Astrophysics 2016年第1期6卷 8-13页

作者： Prithvi Raj Singh Chandra Mani tiwari Ajay kumar Saxena Department of Physics Awadhesh Pratap Singh University Rewa India

In the present work, the study of influence of solar activity, cosmic ray intensity and geomagnetic activity on Earth’s climate during solar cycles 22, 23 and 24 has been done. The change in Earth’s climate, specifically the change in the global mean temperature has been associated with the variation of some solar activity indices, cosmic ray intensity and geomagnetic activity indices in the period of 1986-2014 (Till Dec.). The important solar indices that are total solar irradiance (TSI), Sunspot Number (SSN), F10.7 index, Cosmic Ray Intensity (CRI) Kiel (NM), geomagnetic activity indices Auroral Electrojet Index (AE) and aa index, have been presented. The study of the Earth’s climate in relationship with solar activity, cosmic ray intensity and geomagnetic activity has been analysed with variations and correlations. The variations of SSN with CRI are in anti-phase;SSN with F10.7, SSN with TSI, SSN with AE, SSN with aa are in same phase. The correlation of SSN with CRI is strongly negatively correlated;SSN with F10.7, SSN with TSI is strongly positively and SSN with AE, SSN with aa positively correlated to averaging solar cycles 22, 23 and 24. The Earth’s climate will be affected by the solar activity, cosmic ray intensity and geomagnetic activity.

关键词： Solar Activity Geomagnetic Activity Cosmic Ray Intensity

Tandem rapid manufacturing of Inconel-625 using laser assisted and plasma transferred arc depositions

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Advances in Manufacturing 2013年第4期1卷 305-313页

作者： P.Bhargava C.P.Paul C.H.Premsingh S.K.Mishra atul kumar D.C.Nagpure Gurvinderjit Singh L.M.Kukreja Laser Material Processing Division Raja Ramanna Centre for Advanced Technology Laser Materials Development and Devices Division Raja Ramanna Centre for Advanced Technology

This paper presents an investigation on depo- sition of Inconel-625 using laser rapid manufacturing （LRM） and plasma transferred arc （PTA） deposition in individual and tandem mode. LRM has advantages in terms of dimensional accuracy, improved mechanical properties, finer process control, reduced heat input and lower thermal distortion, while PTA scores more in terms of lower initial investment, lower running cost and higher deposition rate. To quantify the clubbed advantages and limitations of both processes, these were studied individually and in tandem. A number of samples were deposited at different process parameters like power, scan speed, powder feed rate. They were subjected to tensile test, adhesion-cohesion test, impact test and micro hardness measurement. The results of individual tests showed the comparable mechanical prop- erties with i20% variation. The mixed dendritic-cellular and dendritic-columnar microstructures were respectively observed for LRM and PTA deposits with a distinct inter- face for the case of tandem deposition. The interface strength of tandem deposits was evaluated employing adhesion-cohesion test, and it was found to be （325 i 35） MPa. The study confirmed the viability of LRM and PTA deposition in tandem for hybrid manufacturing.

关键词： Tandem rapid manufacturing - Laserrapid manufacturing （LRM） ~ Plasma transferred arc（PTA） deposition ~ Inconel-625

Extraction and Enrichment of Copper by Liquid Emulsion Membrane Using LIX 664N

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Journal of Environmental Protection 2014年第17期5卷 1611-1617页

作者： Rashmi kumar Dahyalal J. Shah Krishna Kant tiwari D. J. Sanghvi College of Engineering Mumbai India Mukesh Patel School of Technology Management & Engineering (NMIMS) Mumbai India Jaypee University of Engineering and Technology (Guna) Madhya Pradesh India

Process intensification using liquid emulsion membranes (LEMs) for extraction of copper has been studied in this work. In LEM process the extraction and stripping processes are combined in one stage. The solubility of the solute or the chemical affinity between the solute and carrier reagent in the membrane results in the separation of the solute from the feed mixture. In this work the membrane phase comprised of LIX 664N as the extractant dissolved in kerosene and Span 80 as surfactant. The stripping phase was sulfuric acid with 180 g/l concentration and feed phase had copper concentration of 3.5 g/l. Effect of various process parameters such as batch contact time, speed of agitation, W:O ratio and treat ratio has been experimentally investigated to get better insight of the process. The maximum enrichment of copper in the internal phase obtained was 11.6 times with batch contact time of 10 minutes, agitation speed of 300 rpm and treat ratio of 6:1.

关键词： Extraction Enrichment Liquid Emulsion Membranes LIX 664N Copper

Time Varying Deceleration Parameter in f(R, T) Gravity

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Journal of Applied Mathematics and Physics 2021年第5期9卷 847-855页

作者： Rishi kumar tiwari Sushil kumar Mishra Sateesh kumar Mishra Değ er Sofuoğ lu Department of Mathematics Government Model Science College Rewa India Department of Mathematics Kashi Naresh Govt. P. G. College Gyanpur India Department of Physics Istanbul University Istanbul Turkey

In the present study, a homogeneous and anisotropic LRS Bianchi type I universe model is considered in f(R, T) theory of gravity. In order to find an exact solution of the field equations of the model, the model presented is based on a unique condition of periodically time varying deceleration parameter. The physical and geometrical characteristics of the universe model have been studied. It has been shown that the model has point-type singularity and all the cosmological parameters possess periodic time behavior. The model has a cyclic expansion history, for example, the model starts with the decelerating expansion, and later it transits to an accelerating phase of expansion and then goes to super-exponential phase of expansion in a period.

关键词： Periodic Deceleration Parameter f(R T) Gravity Bianchi Type-I Universe

A set of SCAR markers in cluster bean (Cyamopsis tetragonolobaL. Taub) genotypes

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Advances in Bioscience and Biotechnology 2014年第2期5卷 131-141页

作者： Pratibha Sharma Vinod kumar K. Venkat Raman Kapil tiwari Department of Bioscience & Biotechnology Banasthali University Rajasthan India National Research Center on Plant Biotechnology IARI New Delhi India

Cluster bean, one of the most important cash legume crop has played an increasingly important role in wide range of industries. Owing to the significance of molecular marker studies in numerous applications including in genetic improvement of crops, there is an obvious need to undertake such studies in cluster bean. In the present work, 35 genotypes of cluster bean were collected from different states of India and analyzed using RAPD and ISSR markers. Further SCAR marker system was introduced in order to increase the reproducibility of the polymorphism and specificity. For this polymorphic (RP-3, 1000 bp;RP-19, 1250 bp and 1100 bp) and geographical specific bands (RP-9, 650 bp) from RAPD as well as genotype specific band (IS-8, 550 bp) from genotype RGC-1031 (Rajasthan) from ISSR were selected and converted into SCAR markers. The study revealed first set of sequence-based SCAR markers in cluster bean which found more specific information using RAPD and ISSR profiles. One genotype specific SCAR-20 for RGC-1031 (tolerant genotype against Macrophomina phaseolina), could be used to prove identity of the genotype for improvement as well for its genetic purity assessment. Another SCAR-8 was selected due to its specificity for cluster bean genotypes from Rajasthan which might be important for population admixture studies.

关键词： Cluster Bean ISSR RAPD SCAR

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

Separation of Copper and Nickel by Solvent Extraction Using LIX 664N

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Journal of Environmental Protection 2013年第4期4卷 315-318页

作者： Rashmi kumar Dahyalal J. Shah Krishna Kant tiwari D. J. Sanghvi College of Engineering Mumbai India Jaypee University of Engineering and Technology (JUET) Madhya Pradesh India Mukesh Patel School of Technology Management & Engineering (NMIMS) Mumbai India

Separation of copper and nickel by liquid-liquid extraction from aqueous solutions was studied using LIX 664N in kerosene as solvent. Both metals were taken in their sulfate form and ratio of copper to nickel in feed solutions was maintained as 10:1. LIX 664N concentration in kerosene was varied from 10% to 40% (v/v) and its effect was studied on percent extraction of copper and nickel for organic to aqueous (O:A) phase ratio of 2:1 at pH 2. Experimental results showed that at pH 2, copper was selectively extracted from its mixture with nickel. Selectivity for copper extraction was as high as 6000 with 40% LIX 664N. Calculations using extraction isotherm indicate almost complete recovery of copper in two stages with O:A ratio of 1:1 and in one stage with O:A ratio of 2:1. After extraction of copper, the pH of raffinate containing nickel was adjusted to a value of 9 by addition of ammonia solution. The effect of LIX 664N concentration on extraction of nickel was studied. Up to 80% nickel could be extracted with 30% LIX 664N at O:A phase ratio of 2:1. Stripping of copper from the organic phase with 180 g/l sulfuric acid at O:A phase ratio of 1:1 gave 98.5% copper recovery in a two-stage operation.

关键词： Copper Nickel LIX 664N Solvent Extraction Distribution Coefficient Selectivity

ACTIVE-A Real Time Commit Protocol

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Wireless Sensor Network 2010年第3期2卷 254-263页

作者： Udai Shanker Nikhil Agarwal Shalabh kumar tiwari Praphull Goel Praveen Srivastava 不详

Many existing real time commit protocols try to improve system performance by allowing a committing cohort to lend its data to an executing cohort, thus reducing data inaccessibility. They block the borrower from sending WORKDONE/PREPARED message and restrict them from lending data so that transaction abort chain is limited to one. Thus, transaction execution time increases. This paper proposes a modified real time commit protocol for distributed real time database systems (DRTDBS), Allow Commit Dependent and in Time borrowers for Incredible Value added data lending without extended abort chain (ACTIVE), where borrower cohorts are categorized as commit and abort dependent. Further, the commit dependent borrowers can lend data to executing cohorts with still limiting the transaction abort chain to one only and reducing the data inaccessibility. Also, an incoming executing cohort having borrowing factor greater than one can only borrow the dirty data items from lender. This minimizes the fruitless borrowing by the cohort. The performance of ACTIVE is compared with PROMPT, 2SC and SWIFT protocols for both main memory resident and disk resident databases with and without communication delay. Simulation results show that the proposed protocol improves the system performance up to 4% as transaction miss percentage.

关键词： Distributed Real Time Database System Commit Protocol Conflict Resolution Dependency Lender Borrower

Assessment of Antifungal Activity of Some Himalayan Foliose Lichens Against Plant Pathogenic Fungi

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American Journal of Plant Sciences 2011年第6期2卷 841-846页

作者： Priti tiwari Himanshu Rai Dalip kumar Upreti Suman Trivedi Preeti Shukla 不详

In vitro antifungal activity of the acetone, methanol and chloroform extracts of four lichen species viz, Bulbothirx setschwanensis, Everniastrum nepalense, Heterodermia diademata, Parmelaria thomsonii were investigated against seven plant pathogenic fungi (Aspergillus flavus, A. fumigatus, Alternaria alternata, Fusarium oxysporum, F. solani, F. roseum and Penicillium citrinum) with reference to commercially available synthetic antifungal drug Ketoconazole (positive control). Lichen secondary metabolites were extracted using Soxhlet extractor and were further recovered through gentle evaporation of solvents in rotatory evaporator. Antifungal activity was analysed employing BauerKirby disc diffusion assay. Acetone and methanol extracts of lichenized fungi were found more effective against tested plant pathogenic fungi. Principal component analysis concluded that though, Ketoconazole was effective against four of the tested plant pathogenic fungi, acetone and methanol extracts of lichens were comparatively more effective against some broad spectrum plant pathogenic fungi (Fusarium oxysporum, F. solani, F. roseum).

关键词： Acetone Extract Antifungal Activity Bauer- Kirby Disc Diffusion Assay Foliose Himalayan Lichen Methanol Extract Rotary Evaporator Secondary Metabolites Soxhlet Extractor