Hemalatha S.,IT BHU
Turkish Journal of Botany | Year: 2011
In this study, the roots of Viburnum punctatum Buch.-Ham. ex D.Don, Viburnum coriaceum Blume, and Viburnum erubescens Wall. ex DC. were collected from the Nilgiri and Coimbatore hills in Tamil Nadu, India. Transverse sections of plant roots were prepared with the aid of a rotary microtome. The sections, each at a thickness of 10 μm, were stained and fixed in Canada balsam and the morphoanatomical features of each specimen were noted. The specimens were powdered using a mechanical grinder and were mounted in suitable media for starch grains, sclereids, druses, fibres, and vessels. Morphoanatomical features of diagnostic importance were recorded under different magnifications, followed by the determination of dimension and histological features of root components using a calibrated eyepiece micrometer and a polariser. The starch grains averaged 12, 17, and 20 μm in diameter in V. erubescens, V. punctatum, and V. coriaceum, respectively. The fibres were about 1 mm long in V. punctatum and V. coriaceum, whereas those found in V. erubescens specimens were around 700 μm. Qualitative chemical screening indicated that phytosterols, triterpenoids, and phenolic compounds and their glycosides were among the commonly found phytoconstituents. © TÜBİTAK.
Krishna K.V.M.,Bhabha Atomic Research Center |
Tripathi P.,IT BHU |
Hiwarkar V.D.,Indian Institute of Technology Bombay |
Pant P.,Indian Institute of Technology Bombay |
And 3 more authors.
Scripta Materialia | Year: 2010
An automated reconstruction of the pre-transformation microstructure from the microtexture data of the post-transformation product phase is proposed. The method involves identifying triplets of neighboring product grains with a common variant and linking such neighboring triplets via a generalized misorientation criterion. The approach is non-iterative and extremely efficient computationally. The method was tested successfully for different post-transformation microstructures in zirconium. © 2009 Acta Materialia Inc.
Al-Radaei S.A.M.,IT BHU |
Mishra R.B.,IT BHU
International Journal of Intelligent Information Technologies | Year: 2011
Course sequencing is one of the vital aspects in an Intelligent Tutoring System (ITS) for e-learning to generate the dynamic and individual learning path for each learner. Many researchers used different methods like Genetic Algorithm, Artificial Neural Network, and TF-IDF (Term Frequency- Inverse Document Frequency) in E-leaning systems to find the adaptive course sequencing by obtaining the relation between the courseware. In this paper, heuristic semantic values are assigned to the keywords in the courseware based on the importance of the keyword. These values are used to find the relationship between courseware based on the different semantic values in them. The dynamic learning path sequencing is then generated. A comparison is made in two other important methods of course sequencing using TF-IDF and Vector Space Model (VSM) respectively, the method produces more or less same sequencing path in comparison to the two other methods. This method has been implemented using Eclipse IDE for java programming, MySQL as database, and Tomcat as web server. Copyright © 2012, IGI Global.
Verma A.K.R.,Indian Institute of Technology Kharagpur |
Kumar A.,IT BHU
Journal of Mines, Metals and Fuels | Year: 2011
About 75% of India's energy supply is from 120 coal based thermal power plants and produce about 160 mt of fly ash in 2009. An estimate shows that, a 200 MW power plant generates about 80 tonnes of fly ash per hour. According to Gazette of India 2008, "fly ash" means and includes all categories or groups of coal or lignite ash generated at the thermal power plant such as electrostatic precipitator (ESP) ash, dry fly ash, bottom ash, pond ash and mound ash. Dumping of fly ash occupies huge land space (about 1,00,000 acres in 2005), and it is estimated that about one acre per MW of land is needed for its disposal. Fly ash produced as a result of burning of coal has detrimental effects on environment. There are ample scope for its environmental friendly utilization in different applications in underground mines such as a raw material for backfill, support unit, construction work in underground coal mines as well as for recultivation and restoration purposes of opencast mines due to its pozzolanic characteristics. In this work, an investigation is carried out to develop a fly ash based composite of considerable compressive strength. The composites thus developed can be used to make a load bearing units in an underground mines.
Raju K.,IT BHU |
Harsha A.P.,IT BHU |
Ojha S.N.,IT BHU
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology | Year: 2011
In the present study, the microstructural features, wear characteristics, and corrosion behaviour of spray cast Al-12Si, Al-15Si, and Al-20Si alloys have been investigated. The alloys were spray cast and hot isostatically pressed. Hot isostatic pressing has considerably reduced the porosity in spray cast alloys. The microstructure of spray cast alloys showed fine and globular-shaped Si particles in the Al matrix in contrast to needle-type eutectic Si and blocky-type primary Si in the Al matrix in chill cast alloys. The dry sliding wear tests showed that the wear rates of spray cast alloys are invariably lower and the potentiodynamic polarization tests showed that the corrosion resistance of spray cast alloys is considerably higher than that of chill cast alloys. The high wear and corrosion resistance of spray cast alloys have been discussed in the light of the microstructural modification induced during the spray casting process.
Singla P.,Thapar University |
Mehta R.,Thapar University |
Berek D.,Slovak Academy of Sciences |
Upadhyay S.N.,IT BHU
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2012
Poly(lactic acid) (PLA) has been synthesized catalytically under vacuum by microwave (MW) irradiation using stannous octoate (SnOct 2) as catalyst. The polymerization is carried out at 180°C up to 30min. PLA with a molar mass of 10 4 g.mol -1 and a yield over 97% was produced in 20min by the ring-opening polymerization of L-lactide using (SnOct 2) as catalyst under microwave irradiation with a power level of 180W. The structural investigations are done by NMR and FTIR. The average molar mass of PLA is determined by means of size exclusion chromatography, (SEC). The characterization is done using three different columns. The polymerization rate is much faster with microwave heating than conventional heating. Microwave irradiation gives rapid energy transfer and high-energy efficiency, hence, a faster reaction rate. Copyright © Taylor and Francis Group, LLC.
Rai R.,IT BHU |
Shrivastva B.K.,IT BHU
Proceedings of the Institution of Civil Engineers: Ground Improvement | Year: 2012
Plants are used to reduce erosion and stabilise slopes in many places. The present paper discusses the reinforcement effect of two different types of grass (Cynodon dactylon and Imperata cylindrica) roots with soil. Root distributions are also investigated with depth and lateral directions. The shear strength test is conducted to understand the root interaction system with soil. Pull-out tests are performed for Imperata cylindrica to investigate the interaction of roots with soil. The increased shear strength is calculated by a large shear box instrument (30 cm 3 30 cm 3 15 cm). The results show that the roots significantly increase the shear strength of soil. This is primarily dependent on the properties of the roots and their profile. The increased shear strength owing to Imperata cylindrica and Cynodon dactylon grass is 36 kPa and 11 kPa respectively. Relative shear strength is also defined and used to quantify the reinforcement capacity of grasses. The relative shear strength owing to Imperata cylindrica grass is around three, whereas that owing to Cynodon dactylon grass is approximately two.
Gupta S.,IT BHU
International Journal of COMADEM | Year: 2011
In Maintenance design for any system can be divided into two components; (i) maintenance policy component (ii) maintenance scheduling component. The current research paper focuses on the maintenance scheduling for production equipment keeping cost control as the primary goal. The paper highlights the resource prioritization and the usefulness of an importance measure based ranking of subsystems/components for scientific allocation of limited resources. Based on the detailed understanding of maximizing benefits from available resources, a cost-effective importance measure has been evolved and proposed for scheduling various maintenance tasks involved in heavy duty belt conveyors operating in an underground coal mine. © 2011 COMADEM International.
Verma A.K.,IT BHU |
Deb D.,Indian Institute of Technology Kharagpur
Geotechnical and Geological Engineering | Year: 2010
The paper discusses the concept and methodologies for the development of longwall face stability index (LFSI). LFSI is used for estimation of chock-shield pressure and face convergence. The index comprises of engineering properties of main roof, depth of mining, different support capacities and mechanical properties of coal seam being mined and provides a numerical value in the range of -6.17 to 8.13. In this study, 324 finite element models of longwall panel are developed based on various combinations of geomining conditions of Indian coal measure strata. The LFSI is an outcome of the results from finite element models. This paper illustrates a real life example for the estimation of chock shield pressure and face convergence based on LFSI. Validation of the LFSI based calculation is carried out with the field monitored data and found that the LFSI based approach is sufficient to forecast face stability parameters at longwall face. © 2010 Springer Science+Business Media B.V.
Tripathi D.,Mathematics Group |
Pandey S.K.,IT BHU |
Das S.,IT BHU
Acta Astronautica | Year: 2011
The present investigation deals with the peristaltic transport of generalized Burgers' fluid with fractional element model in a channel. The analysis is carried out under long wavelength and low Reynolds number assumptions. An efficient mathematical tool, namely, Adomian decomposition method, is used to obtain the analytical approximate solutions of the fractional differential equation. The channel is governed by the propagation of sinusoidal waves that help the walls contract and relax but not expand beyond the natural boundary. The expressions of axial velocity, volume flow rate and pressure gradient are obtained. The effects of the fractional parameters and the material constants are discussed on pressure difference and the friction force across one wavelength. The comparative studies for various models of viscoelastic fluids such as fractional generalized Burgers' model, generalized Burgers' model, fractional Burgers' model and Burgers' model are performed. It is inferred that the movement of viscoelastic chyme with generalized Burgers' model through the small intestine is favorable in comparison to the movement of viscoelastic chyme with fractional generalized Burgers' model. © 2010 Elsevier Ltd. All rights reserved.