002565   Rudraiah N;Nagaraj C;Nagaraj H N (UGC-Centre for Advanced Studies in Fluid Mechanics, Mathematics Dep, Bangalore Univ CHIU-ONNG, Bangalore-560 001) : Electrohydrodynamic dispersion of macromolecular components in biological bearing. J Energy Heat Mass Transfer 2006, 28(4), 261-80.

The electrohydrodynamic(EHD) dispersion of macromolecular components in a biological bearing consisting of a poorly conducting synovial fluid both in the cavity of the bones and in the bounding porous cartilage of finite thickness is investigated It is shown that the effect of finite thickness of the cartilage compared to its large thickness is to increase the dispersion coefficient in artificial joints compared to that in the natural joints.

4 illus, 13 ref

002564   Rathore S S;Lakshmi Narayana V (Mining Engng Dep, M.P. Univ of Agric and Technol, Udaipur-313 001) : Studies on flyrock at limestone quarries. J Mines Metals Fuels 2006, 54(6-7), 130-4.

Observes flyrock distances for 16 blasts at four limestone quarries along with blast design parameters are presented. The influence of blasthole diameter, burden, stemming length, powder factor and the condition of blastholes (dry or wet) on generation of flyrock is analyzed and the most critical parameters for flyrock control are identified. Based on the analysis of results, suggestions are given to minimize the flyrock hazards at limestone quarries of cement grade situated in the state of Rajasthan.

4 illus, 2 tables, 18 ref

002563   Ranganath B J;Viswanath G (Mechanical Engg, Vidya Vikas Inst of Engng and Technol, Mysore-570 010) : Study on shite layer and surface texture in laser cutting of 304 grade stainless steel. Ultra Scient phys Sci 2006, 18(2), 155-60.

The formation of white layer on cut surface is found on cutting stainless steel with Carbon dioxide laser using oxygen as assist gas. The composition of such a layer is found to be depleted of elements of the base cut material. This weakens the cut surface and affects the cut surface texture and functioning of the cut surface. The analysis of the laser cut surface is discussed in this paper.

7 illus, 1 table, 9 ref

002562   Rajagopalan S;Antonia R A (NO, School of Engineering, Newcastle Univ, Australia, Email: mesr@cc.newcastle.edu.au ) : Turbulence and drag control in jet and wake flows. Sadhana 2007, 32(1-2), 133-44.

Structures of plane and circular jets were modified by using active, passive and an active-passive (hybrid) combination to investigate the phenomenon of turbulence control using hot-wire anemometry. Active control was achieved by-exciting the flow by using either an acoustic speaker or vibrating piezoceramic elements, whereas passive control was achieved by placing a slender object such as a thin wire or a ring, a mesh or a honeycomb section downstream of the nozzle exit plane. Turbulence enhancement and suppression in plane- and circular-jet mixing layers could be achieved by employing active techniques, whereas passive techniques essentially yielded turbulence reduction. For a circular cylinder, a significant reduction in drag was obtained by placing a cylinder of small diameter upstream of the main cylinder. The total drag of the two cylinders was smaller than that of a single cylinder alone. Hot-wire measurements indicate significant changes to the downstream flow structure associated with the observed drag reduction. Our investigations indicate that different types of modification and excitation can yield different but useful outcomes.

9 illus, 22 ref

002561   Promvonge P (Mechanical Engineering Dep, Mahanakorn University of Technology, Bangkok 10530, Thailand) : Effect of V-nozzle inserts and snail vutle free-spacing entry an beat tranfea in heat esccliangee. J Energy Heat Mass Transfer 2006, 28(4), 225-39.

An experiment has been conducted to study the effect of combined V-nozzle turbulator inserts and snail entrance with free-spacing entry on heat transfer rate in a tube. Vª-nozzle pitch ratios (PR=I/D=I+s/D) of PR = 2.0, 4.0, and 7.0 are selected and tested with a snail entrance of the test tube. The experimental results show that the increase in heat transfer coefficients for using V-nozzle inserts and snail entrance is strongly influenced by nozzle-induced reverse/re-circulation motion and snail-induced vortex/swirl motion, especially at high Reynolds number. The correlation in the form of Nusselt number as a function of the Reynolds number (Re), Prandtl number (Pr) and pitch ratio (PR) is presented. The experimental result reveals that for the rise of Reynolds number, the Nusselt number considerably increases while the enhancement efficiency decreases. The increases in mean heat transfer rate and the maximum enhancement efficiency obtained from using PR = 2.0, 4.0, and 7.0, are found to be 278%, 247% and 230%; and 1.1, 1.04, and 1.0, respectively.

9 illus, 23 ref

002560   Prashant;Pandey J K;Kumbhakar D;Mandal P K; Guha B (NO, Central Mining Res Inst, Dhanbad-826 001) : Model study to optimize baricade configuration for ash stowing. J Mines Metals Fuels 2006, 54(6-7), 142-6.

8 illus, 4 ref

002559   Prasad G M;Vishnoi R K;Singh A K (NO, , Tehri Hydro Development Corporation Ltd.) : Computation of probable maximum flood for spillways. Wat Energy int 2007, 64(1), 92-8.

Water availability and design flood are the two important hydrological aspects, which need careful assessment for planning & design of a storage project. For these hydrological studies, long-term rainfall and discharge data are required. When the project of Tehri dam was conceived, very scanty data was available in respect of rainfall and river discharge at Tehri dam site. In absence of adequate data, different statistical/conceptual approaches were used to make assessment as regard to the water availability and maximum design flood at Tehrh Additional river discharge data became available. Water availability study was, therefore, updated, taking into account this additional data. Similarly, the assessment of maximum design flood made earlier was also re-checked by developing design unit hydrograph through conceptual modelling, using short-interval rainfall data. Apart from giving an overview of the initial hydrological studies, deals with updated hydrological studies carried out since 1984 up to January 1990.

2 illus, 2 tables, ref

002558   Prasad G M;Vishnoi R K;Govil R (NO, , Tehri Hydro Development Corporation Ltd.) : Initial filling of the project reservoir. Wat Energy int 2007, 64(1), 112-21.

Provides the specified Central Water Commission criteria for initial filling of reservoir, reservoir operation during initial filling for the specified criteria, its implications on overall filling schedule, actual reservoir filling in monsoon 2006 and proposed filling schedule up to Full Reservoir Level.

ref

002557   Prasad G M;Vishnoi R K (NO, , Tehri Hydro Development Corporation Ltd.) : Distinctive features of design and construction of stilling basin of Tehri chute spillway. Wat Energy int 2007, 64(1), 273-81.

Discusses the hydraulic design indicating the various alternatives studied and firming up of the final alternative. The structural design is also discussed indicating the loads considered and the design scheme adopted as per the requirement. Finally, construction methodology adopted to carry out the concreting in the most critical initial portion of Stilling Basin is briefly explained.

6 illus, 1 table, ref

002556   Prasad G M;Singh S;Routela T S (NO, , Tehri Hydro Development Corporation Ltd.) : Design and construction aspects of butterfly valve and penstock assembly chambers for Tehri. Wat Energy int 2007, 64(1), 297-302.

Deals with the design and construction aspects of these caverns of Tehri HPP constructed in adverse geological conditions with narrow rock pillar in between.

2 illus, 4 tables, ref

002555   Prasad G M;Singh S;Jain A (NO, , Tehri Hydro Development Corporation Ltd.) : Application of design techniques in construction of crane beams in machine hall. Wat Energy int 2007, 64(1), 309-12.

3 illus, 2 tables, ref

002554   Prasad G M;Routela T S;Jain M K (NO, , Tehri Hydro Development Corporation Ltd.) : Transient study for downstream expansion chamber. Wat Energy int 2007, 64(1), 318-26.

Described the necessity of downstream expansion chamber and reasons for omission of surge tank in upstream of the water conductor system in Tehri HPP, and gives the main dimensions and design parameters for downstream expansion chamber, design methodology for extreme transient levels for downstream expansion chamber provided in Tehri HPP.

5 illus, 1 table, 2 ref

002553   Prasad G M;Narang J L;Singhal S (NO, , Tehri Hydro Development Corporation Ltd.) : Design aspects of the dam design. Wat Energy int 2007, 64(1), 143-9.

Under the Stage-I of Tehri Hydro Electric Project, a 260.5m high Earth and Rock-fill dam has been constructed on river Bhagirathi in district Tehri Garhwal of Uttarakhand. The project area is in high seismic zone and falls in Zone-IV of the seismic zoning map of India. In such complex environment, rockfill dam with slightly inclined clay core has been designed by utilizing locally available fill materials, with little or no processing. Design of the dam has been finalized by involving internationally renowned expert Institutes in the field viz. HPI, Moscow and DEQ, IIT, Roorkee. Geometry of the dam core has been optimized by carrying out detailed stress-strain analysis. Extensive surface as well as sub-surface treatment of the core seat foundation i.e.grouting has been done for improving its properties. For monitoring the health of the dam during construction and operation period, a large number of instruments have been installed within the body of dam and its foundation. One of the unique features of this dam is the provision of inspection galleries within the core of the dam through which physical inspection and monitoring of the dam behaviour is possible during the operation period of the project.

6 illus, ref

002552   Prasad G M;Narang J L;Singhal S (NO, , Tehri Hydro Development Corporation Ltd.) : Alternative schemes considered for the evolution of dam. Wat Energy int 2007, 64(1), 126-32.

Tehri dam project is one of the prestigious mega hydroelectric projects of the nation which shall harness the vast hydro potential of mythical river Bhagirathi. The 1st stage of the project involved construction of a 260.5 m high earth & rock fill dam across the river Bhagirathi at Tehri, an underground power house (1000 MW), a spillway system etc. Number of alternatives with the variation in type, location, number and height of structures have been considered before the finalization of the present scheme. A single dam with low height, two dams one each on Bhagirathi & Bhilangana river, and possibility of run-of-the river scheme etc. were considered. The cost & benefits from these schemes were studied in detail. Finally, on the basis of techno-economic considerations, it was decided that the present scheme is the best scheme for harnessing the benefits from water of Bhagirathi and Bhilangana at Tehri.

6 illus, 1 table, ref

002551   Prasad G M;Narang J L;Singh S;Chauhan S K (NO, , Tehri Hydro Development Corporation Ltd.) : Reservoir rim stability for dam. Wat Energy int 2007, 64(1), 218-26.

Rock-fill dam (260.5 m high) has been constructed across river Bhagirathi on downstream of the confluence with the river Bhilangana. The gross storage at FRL 830 m, in the two long reservoir limbs along Bhagirathi and Bhilangana rivers, is estimated as 3540 MCM. The region consists of a rugged mountainous terrain with steep slopes of varying types of rock formations. Numerous superficial small slides as well as deep slides have been reported to have occurred in the past in the Bhagirathi and Bhilangana Valley. The small-scale slides could result in silting of the reservoir and also create deforestation posing a threat to the ecology of the region. Therefore, the various laboratory & field investigations were got done to identify the weak & unstable hill slopes which otherwise may pose a threat to the dam or the ecological balance of the region.

2 illus, 5 tables, 4 ref

002550   Prasad G M;Narang J L;Shailendra Singh;Atul Jain (NO, , Tehri Hydro Development Corporation Ltd.) : An overview of 1000 MW Tehri pumped storage scheme [PSP]. Wat Energy int 2007, 64(1), 466-78.

Deals with the important features of the Tehri Pumped Storage Plant, which is under implementation.

6 illus, 3 tables, ref

002549   Prasad G M;Narang J L;Jain M K (NO, , Tehri Hydro Development Corporation Ltd.) : Hydraulic downpull on fixed wheel emergency maintenance gate in intermediate level outlet [ILO]. Wat Energy int 2007, 64(1), 351-8.

Presents the results of model studies on hydraulic downpull and mathematical calculations carried out to calculate the downpull forces on fixed wheel emergency maintenance gate. Hydrodynamic forces were calculated on model as well as mathematically on various %age openings of gate. Based on static and hydrodynamic forces, self-closure of the gate under unbalanced head of 130.0 m is checked and hoist capacity calculations have been done.

4 illus, 4 tables, 3 ref

002548   Prasad G M;Ghosh K K;Singhal S (NO, , Tehri Hydro Development Corporation Ltd.) : An overview of various investigations for dam. Wat Energy int 2007, 64(1), 133-42.

Overview of various investigations in respect of geological / geophysical explorations and material surveys etc. carried out for Tehri dam.

5 tables, ref

002547   Prasad G M;Ghosh K K;Sehgal V (NO, , Tehri Hydro Development Corporation Ltd.) : Scheme for real time inflow forecasting of Tehri Dam reservoir. Wat Energy int 2007, 64(1), 122-5.

3 illus, 2 ref

002546   Prasad G M;Ghosh K K;Rawat D S (NO, , Tehri Hydro Development Corporation Ltd.) : Scheme for monitoring the behaviour of Tehri dam. Wat Energy int 2007, 64(1), 201-5.

2 ref

002545   Pillai R M;Pillai S G K;Damodaran A D (NO, RRL,CSIR, Thiruvananthapuram-695 019, Email: rmpillai@csrrltd.ren.nic.in) : Shaping of bronze in ancient India - some case studies from South India. Trans Indian Inst Metals 2006, 59(6), 847-64.

Presentation brings out the case histories of the study carried out by the authors on a few ancient metallurgical arts of shaping bronze, which are still being practiced namely. Aranmula metal mirror making, Kadavaloor high tin bronze eating bowl and gong making and lost wax process utilised for making icons, utensils and bells in Swamimalai and Mannar.

29 illus, 15 ref

002544   Paul D K (Earthquake Engineering Dep, Indian Institute of Technology, Roorkee) : Seismic safety analysis of Tehri dam. Wat Energy int 2007, 64(1), 151-61.

Seismic safety of 260.5 m high rock-fill Tehri dam located in seismically active zone has been investigated. Simple stability and linear 2D stress analyses for such a high dam are carried out when subjected to severe ground motions, which are likely to undergo large nonlinear deformations. The dam was later analyzed for various levels of shaking considering all possible worst-case scenarios in Himalayan environs. One such test to a Maximum Credible Earthquake (MCE) producing Peak Ground Acceleration (PGA) 0.5g at the dam site is presented here which includes sequential non-linear static and nonlinear earthquake analyses using the Mohar-Coulomb material model for the rock-fill and the clay core materials. The dam undergoes plastic deformations mostly at the u/s and d/s slopes, which may not lead to any possible failure.

15 illus, 4 tables, ref

002543   Pal T K;Prasad J V (Research Centre Imarat, , Hyderabad-500 069) : Mechanical tuning properties of waveguide-mounted resonant-cap IMPATT Oscillator at Ka-band. Def Sci J 2007, 57(6), 891-7.

Describes the studies of the tuning properties of an indigenously developed resonant-cap continuous wave IMPATT oscillator at Ka-band by changing circuit susceptance through mechanical tuning. It was observed that output power of a resonant-cap IMPATT oscillator passes through a maximum at a particular frequency for a given diode with an optimum combination of cap diameter and cap height. An empirical relation has been found between cap diameter and wavelength of the optimised oscillator, which agrees with the theoretical relation. The effect of sliding short tuner position on the oscillator at optimised condition and the phenomenon of frequency jump in certain positions of sliding short have been studied.

7 illus, 3 tables, 12 ref

002542   Nayak S;Pandmaja G (Civil Engng Dep, National Inst of Technol, Surathkal-575 025) : Slope stability coeficients for steep homogeneous soil slopes. Indian Geotech J 2006, 36(4), 373-82.

Slope stability is one of the most important areas in geotechnical engineering. Various methods are available for stability analysis of soil slopes. In the present work, a computer program has been developed for the stability analysis of single layer homogeneous soil slopes by Bishop and Morgenstern method. The stability analysis has been carried out for various values of c/<103H, angle of internal friction, φ and slope angle, i where c is unit cohesion, <103 is unit weight of soil and H is the vertical height of the slope. Using the program, slope stability coefficients, namely, m' and n' are obtained and presented in the form of tables for various values of c/<103H, i and φ. From these stability coefficients, the factor of safety can be directly calculated. Extent of failure surfaces for various cases has been expressed in the non-dimensional form. The results of the study are of great use for the field engineers.

7 illus, 5 tables, 10 ref

002541   Nawani P C;Khanduri H C;Bahuguna H (NO, , ) : Geotechnical aspects of spillway structures of Tehri dam. Wat Energy int 2007, 64(1), 70-83.

Locating and executing the spillway structures, at different sites, posed certain geotechnical problems, which were tackled detailed geotechnical assessment and by providing suitable foundation treatments and well designed support system. These structures are located on different tectonic blocks of the block tectonic model of Tehri dam project. Along the chute spillway, different bands of phyllitic quartzite massive (PQM) and phyllitic quartzite thinly bedded (PQT) were encountered. Planar failure along the foliation joints and longitudinal (L) shears, due to day-lighting, were noticed and to arrest these planar failures, deeper rock bolts were provided. The junction of the chute spillway with the stilling basin was considered highly vulnerable because of the existence of sheared/deformed rockmass formed by the intersection of the major diagonal (D-1) and longitudinal shears. An 11m wide and 4m deep reinforced shear key was provided. Stilling basin foundation exposed different bands of PQM, PQT and sheared phyllite (SP). Numerous major and minor shear zones, L & D type, were delineated and were provided with dental treatment. The areas occupied by sheared/deformed rock mass were advised for local lowering and backfilling with suitable-strength concrete. The right bank shaft spillway area was assessed critical because of the poor rock mass around D-3 shear (near T-4 shaft) and multiple shear seams as projected along T-3 shaft. During the excavation of T-3 & T-4 shafts and their ducts, planar failures along longitudinal shears, wedge failure and problem of wall convergence was noticed. The junction of the main shafts with the de-aeration ducts was critical because of the reverse curve geometry. Rock bolting and chain link shotcreting were provided as the main stabilisation measures whereas spot bolting and steel rib support were provided in critical reaches. At the swirling device area of T-3 & T-4 shafts, planar failure along foliation joints were recorded due to day lighting of these joints and the area was stabilized by providing 8m long 32mm dia rock bolts along with two layers of shotcrete. No major geotechnical problem was encountered in the excavation of T-1 & T-2 shafts, and they were stabilized by providing rock bolts and shotcreting. The horse shoe shape intermediate level outlet (ILO) was driven through different bands of PQM & PQT. The excavation of the inclined glacis of ILO at the junction with T-3 shaft was very critical, and it was done by taking up smaller segments. Deeper rock bolts were provided on both the walls, and vertical steel channels were extended down to the increased wall sections, to prevent failure from the arch or wall sections, during the excavation at the junction.

2 tables, 5 illus, ref

002540   Nawani P C;Khanduri H C;Bahuguna H (NO, , ) : Geotechnical aspects of the dam foundation. Wat Energy int 2007, 64(1), 58-69.

Foundation of the core and shell areas was geologically mapped and geotechnically assessed. All important shear zones were given dental treatment and the areas LI occupied by sheared/deformed rock mass were lowered and back filled with suitable strength concrete.

5 illus, ref

002539   Navaneethakrishnan P;Srinivasan P S S; Dhandapani S (Mechanical Engng Dep, Kongu Engng Coll, Perundurai-638 051, Email: pnk@kongu.ac.in) : Numerical and experimental investigation of heating ovens. J Energy Heat Mass Transfer 2006, 28(4), 251-60.

Commercial bakery ovens are mainly used for heating food stuffs to a certain temperature level which suits the requirement of the user. Minimum overall energy consumption and minimum variations among the foodstuffs are the essential requirements. In addition, when a new foodstuff is kept inside the oven, it must reach the required temperature at the lowest possible time. To check these aspects, both experimental and numerical investigations are carried out. The measurements are made over a period of 150 minutes with and without foodstuffs. About 7-13°C variations among foodstuffs placed at various locations are observed. The numerical and experimental results have good agreement both in magnitude and trend.

10 illus, 15 ref

002538   Narasimha R (NO, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore-560 064, Email: roddam@caos.iisc.ernet.in) : Wavelet diagnostics for detection of coherent structures in instantaneous turbulent flow imagery: a review. Sadhana 2007, 32(1-2), 29-42.

A review of work over the last decade shows that 2D wavelet techniques applied on flow imagery can provide powerful insights into the nature and life-cycle of coherent structures (the latter through wavelet movies) in turbulent shear flows. The advantage of wavelet techniques in often being able to infer the nature of coherent motion from a single image is emphasized. The techniques are first calibrated by using them on well-known results in the turbulent mixing layer. They are then applied to jets and plumes, and it is shown how off-source heating in such flows can disrupt the coherent structures in the unheated flow. A suitably reduced version of the present method, using discrete wavelet transforms on signals from a finite array of sensors, could be a useful diagnostic tool in near-real-time detection of coherent structures or patterns for the purpose of selecting appropriate control signals to the actuators in a flow-control system.

8 illus, 31 ref

002537   Narang J L;Singhal S;Negi S S (NO, , Tehri Hydro Development Corporation Ltd.) : Scheme of dam foundation treatment. Wat Energy int 2007, 64(1), 185-93.

Presents a brief account of the scheme of foundation treatment adopted at Tehri dam.

6 illus, 1 table, ref

002536   Musla A K;Jaiswal A K (Instruments Research & Development Establishment, , Dehra Dun-248 008) : Effect of image intensifier tube equivalent background illumination or range performance of passive night sight. Def Sci J 2007, 57(6), 877-80.

Effect of increase in equivalent background illumination (EBI) with temperature of second generation (18 mm) proximity focused image intensifier tube on the range performance of a passive night sight has been studied using the image intensifier minimum resolvable contrast model. It has been shown that for ambient temperatures of 40°C and above, the range performance of sight goes down drastically under low-illumination level due to increase in the EBI. Deterioration in range performance is negligible when ambient illumination is relatively high as in case of clear-starlit condition.

2 illus, 2 tables, 5 ref

002535   Mukhopadhyay B;Ray S K;Bandopadhyay A K (R&D Centre for Iron and Steel, SAIL, Ranchi-834 002) : Influence of mould taper on quality and productivity of cast bloom. Steel India 2007, 29(2), 80-5.

Tapering of mould is necessary to compensate for the resultant of shell shrinkage, mould distortion and strand bulging. The air gap and consequently the heat extraction through the mould are controlled by deciding the optimum taper. The present paper reports the influence of magnitude and stage of tapers in bloom mould on the internal quality of cast bloom. Double-stage taper with relatively higher magnitude has shown better performance than single taper. Contribution of the other factors, like, application of EMS ,and lower Mn /S ratio towards better quality and higher casting speed have also been looked into.

2 illus, 2 tables, 4 ref

002534   Mann P P S;Vishnoi R K;Govil R (NO, , Tehri Hydro Development Corporation Ltd.) : Evolution of spillway scheme for Tehri project. Wat Energy int 2007, 64(1), 227-36.

6 illus, ref

002533   Majumder A K;Barnwal J P (RRL, CSIR, , Bhopal) : Concept of separation density in coal preparation-revisited. MGMI Trans 2005, 102(1-2), 69-73.

In coal preparation it is common practice to evaluate the efficiency of a gravity concentrator by knowing the deviation of the actual distribution curve of the product from its ideal distribution. To do this the first task is to find out the separation density from the distribution curve. Some critical comments have been made whether this separation density has any objective oriented relevance or not by giving some illustrative examples.

1 illus, 1 table, 2 ref

002532   Majumdar J;Lekshmi S;Vanathy B (Aeronautical Development Establishment, , Bangalore-560 093) : Automatic classification of aerial imagery. Def Sci J 2007, 57(6), 773-86.

Aerial imagery obtained from reconnaissance platform is voluminous and the defence forces rely on image information to perform intelligent tasks. The application of a well designed automatic image classifier would enhance the end results of different high level applications thereby abridging the effort of a human analyst. Automatic image classifiers could be designed using a training data set for supervised learning or using an unsupervised learning. Proposes a method, which combines both unsupervised and supervised methods of learning.

8 illus, 2 tables, 15 ref

002531   Madhavi Latha G;Murali Krishna A (Civil Engng Dep, Indian Inst of Sci, Bangalore-560 012, Email: madhavi@civil.iisc.ernet.in) : Shaking table studies on reinforced soil retaining walls. Indian Geotech J 2006, 36(4), 321-33.

Presents observations from experiments on models of reinforced soil retaining walls subjected to horizontal base shaking. A computer controlled hydraulically driven single degree of freedom shake table is used in these tests. The test wall is constructed in a laminar box to a size of 750 mm x 500 mm in plan and 600 mm deep. The model retaining walls are constructed in lifts of equal height using sand. Each lift is reinforced with a layer of geotextile and wrapped at the facing. The model is instrumented with accelerometers, soil pressure sensors and L VDTs at different locations. The response of the reinforced retaining walls with the variation in acceleration and frequency of base" shaking and surcharge loading has been monitored and discussed.

17 illus, 3 tables, 15 ref

002530   Krishnamurth P (UCIL, , Narwapahar, Singhbhum, Jharkhand) : Saga of Singhbhum uranium discoveries and exploration. MGMI Trans 2005, 102(1-2), 151-69.

Uranium exploration in India by the Rare Mineral Survey Unit (RMSU, later known as AMD) began during 1950-51 in the 120 km long Singhbhum copper belt with a team of 17 geologists and one physicist. This joint team comprising geologists from Geological Survey of India, Damodar Valley Corporation and the Atomic Energy Commission was led by VR. Khedkar of GSI. The entire belt was divided into 10 sectors and iso-rad survey and prospecting on 8 inches = 1 mile scale was carried out using 8 GM counters. Fifty seven (57) uranium anomalies were discovered from this survey spread between Duarpuram (22°45' 30' ; 85 34') in the west to Baharagora (22° 16' : 86°48') in the east. The subsequent efforts of proving some eleven (11) uranium deposits with systematic follow-up methods including core drilling and exploratory mining including the development of borehole and shot-hole gamma-ray logging and core assay systems for the first time in India during the 1950s and 1960s epitomizes the zeal and dedication towards making the country self sufficient in uranium. By 1965 AMD established significant deposits of uranium at Jaduguda, Bhatin, Narwapahar and Keruadungri which were also taken up for exploratory mining leading to the opening up of India's first uranium mine and mill at Jaduguda in 1967 and the formation of UCIL. The well-focused exploration programme from 1951-1974 including geophysical and radon surveys supported by sound petrological and chemical studies established Singhbhum as a major uranium province with considerable reserves of low grade (0.03 to 0.07%U3O8) uranium. Areas across the Tirukocha fault beyond the presently known deposits both along the strike and depth seem to hold potential for fresh exploration inputs.

2 illus, 2 tables, 31 ref

002529   Krishna M V S M;Murthy P V K;Prasad C M V; Sita Ran V Raju (NO, Chaitanya Bharathi Institute of Technology, Gandipet, Hyderabad-500 075) : Comparative study of the performance of a low heat rejection engine with two different levels of insulation with crude jatropha oil. Indian J envir Prot 2007, 27(1), 51-7.

Alternate fuel research has been the topic of the highest priority in the context of depletion of fossil fuels at an alarming rate and increasing of pollution levels of the engines with conventional fossil fuels. Alcohols and vegetable oils are probable candidates to replace diesel fuels as they are renewable in nature. However, use of alcohols in internal combustion engines is limited in India, as these fuels are diverted to petro-chemical industries and hence much emphasis is given to the non-edible vegetable oils as alternate fuels in internal combustion engines. However, the drawbacks of low volatility and high viscosity associated with non-edible vegetable oils call for hot combustion chamber, which is provided by low heat rejection diesel engine. Investigations are carried out on low heat rejection diesel engines which consist of different degree of insulations, such as (i) air gap insulated piston with superni crown, air gap insulated liner with superni insert, and (ii) air gap insulated piston with superni crown, air gap insulated liner with superni insert and creamic coated cylinder head with crude jatropha with varied injection pressures. Performance is improved with high degree of insulation with vegetable oil in comparison with conventional engine with pure diesel operation.

6 tables, 10 ref

002528   Kothari H M;Srivastava P K;Patil A K (NO, , Tehri Hydro Development Corporation Ltd.) : Computerised control system. Wat Energy int 2007, 64(1), 399-405.

Deals with the various aspects of Computerised Control System highlighting the salient features of equipment.

2 illus, 3 tables, ref

002527   Kothari H M;Srivastava P K;Nitin Kumar (NO, , Tehri Hydro Development Corporation Ltd.) : Evacuation of power from Tehri HPP stage-I. Wat Energy int 2007, 64(1), 406-7.

The salient features of the Power Evacuation arrangement from 4x250 MW Tuehri HPP Stage-l have been described in the paper. The beneficiary States / Union territory gets power through Meerut Sub- Station from 220 kV lines of Power Grid Corporation of India Limited (PGCIL) net work.

1 illus, 1 table, ref

002526   Kothari H M;Srivastava P K;Kumar (NO, , Tehri Hydro Development Corporation Ltd.) : 420 kv gas insulated switchgears & gas insulated bus ducts. Wat Energy int 2007, 64(1), 379-89.

Execution of underground 420 kV SF₆ Gas Insulated Switchgears Gas Insulated Bus ducts has been got done on turnkey basis om M/s SIEMENS AG Germany. The article deals with the various spects of 420 kV SF₆ Gas Insulated Switchgears & Gas Insulated us ducts system, highlighting the salient features of equipment & stallation.

5 illus, 10 tables, ref

002525   Kothari H M;Singh K;Shailendra Kumar (NO, , Tehri Hydro Development Corporation Ltd.) : Ventilation system for Tehri HPP [4x250 MW]. Wat Energy int 2007, 64(1), 390-8.

Tehri powerhouse is an underground powerhouse of 1000 MW capacity. It is equipped with four vertical Fransis turbines, each of 250 MW capacity. Ventilation system has been installed to provide fresh air in the underground powerhouse and remove hot stale air. It maintains comfortable environment for working personnel and removes the heat generated by the equipment.

3 illus, 1 table, ref

002524   Kothari H M;Singh K;Semwal O P (NO, , Tehri Hydro Development Corporation Ltd.) : 250 MW hydro turbine and auxiliaries of Tehri HPP. Wat Energy int 2007, 64(1), 359-66.

Describes the salient features of their turbine and its auxiliaries provided in the powerhouse.

1 illus, 2 tables, ref

002523   Kothari H M;Mani M;Joshi L P (NO, , Tehri Hydro Development Corporation Ltd.) : Generator transformer. Wat Energy int 2007, 64(1), 373-8.

Most of underground powerhouses in India employ a bank of 3 single-phase Generator Transformers to evacuate generated power due to its enormous advantage in transportation as well as in handling in difficult hilly sites. In case of Tehri HPP, 3-phase Generator Transformer is used which is installed in close proximity of machine hall. Tehri GT's are housed in a transformer hall cavern, which is in parallel to the machine hall of underground powerhouse having 4 units of 250 MW each. Generator Transformers have been supplied and erected by BHEL, Bhopal.

2 illus, 3 tables, ref

002522   Kothari H M;Mani M;Joshi L P (NO, , Tehri Hydro Development Corporation Ltd.) : Hydro generator & excitation system. Wat Energy int 2007, 64(1), 367-72.

Generator and Excitation Equipment have been manufactured at "Uraielectrotyazhmash" Plant, Ekterinburg, Russia. Erection of the equipment has been carried out by BHEL under the supervision of experts of M/s Power Machine Russia.

3 tables, ref

002521   Khanduri H C;Bahuguna H;Nawani P C (NO, , ) : Rock mass characteristics of underground caverns. Wat Energy int 2007, 64(1), 84-91.

Construction of underground powerhouse at Tehri was inevitable because of non-availability of the space on the surface and the huge excavation (required to accommodate the powerhouse) of the steep back slopes. Excavation of the two huge cavities of the powerhouse complex i. e.,machine hall and transformer hall was tackled carefully. Geotechnical assessment made earlier revealed that both these cavities are located in the most competent rock mass at Tehri dam site i.e. phyllitic quartzite massive (PQM) and phyllitic quartzite thinly bedded (PQT) Grade-l. Considering the geotechnical parameters including the in-situ stress measurements, the alignment of these cavities was preferred in N0209 direction. As the alignment was also against the dip direction, the excavation in these cavities was free from any major failure. These gigantic caverns were stabilized by means of rock bolting and shotcreting barring a patch in the crown of machine hall where a 5m band of deformed rock mass, associated with a major longitudinal shear, was encountered. The rock cover between the two cavities was insufficient (i.e. less than 2D), because of which problem of convergence was recorded during the excavation of the bus ducts in the common wall. Multiple bore hole extensometers (MPBAX) and load cells were installed to monitor the rate and extent of convergence, and a number of deep cable anchors (blind and through) were installed to stabilize the area.

3 illus, 3 tables, ref

002520   Khaleghi H;Ganji D D;Rajabi A (Mechanical Engineering Dep, Mazandaran University, Babol, P.O. Box 484 Babol, Mazandran, Iran) : Initiative perturbaction and Laplace transform methods for hyperbolic heat conduction equation. J Energy Heat Mass Transfer 2006, 28(4), 241-50.

In many cases, thermal properties of metals and heat flux are not constant. In general, analytical solutions to these equations are impossible, so a new method to obtain approximate solution to these kinds of equation has been implemented. By applying a new initiative to perturbation method, transforming a ninlinear equation to some linear partial differential equations. using Laplace transform method and supposing a polynomial shape function as an approximate solution to the equation and also using a kind of weighted residual method, called the collocation method. one obtained the solution to the equation. By applying this method to a nonlinear hyperbolic heat transfer equation, one will find out that the polynomial shape function in the heat transfer region, especially at the ends of the region, leads to some errors. These errors can be eliminated by changing the value and order of the small parameter used in the perturbation method and changing the order and the type of the shape function from the polynomial function to the exponential function.

2 illus, 13 ref

002519   Karmakar N C;Aruna M;Rao Y V;Uday Kumar; Yeragatti R (Mining Engng IT Dep, Banaras Hindu Univ, Banaras) : Haul road illumination design based on reflected light and surface wetness - as innovative approach. MGMI Trans 2005, 102(1-2), 103-9.

Highlights the significance of surface wetness and its reflectance in the design of haul roads whose texture depth is significantly high. Design under wet condition would naturally provide satisfactory illumination under dry condition as well. But this would incur an excess cost of about 4% for iron ore bench and about 24% for overburden bench haul roads under study. Indian mining illumination standards are based on incident light without mentioning about uniformity ratio. Proposes that the concept of reflected illuminance and surface wetness be incorporated while formulating new guidelines for Indian mines lighting.

4 tables, 5 ref

002518   Jatana B L (Irrigation Dep, , Former Engineer-in-Chief, U.P) : Building Tehri mega dam in Himalayas challenges in design and construction. Wat Energy int 2007, 64(1), 20-45.

Successful completion of India's highest dam across Bhagirathi (Ganga)-the third highest Embankment dam in the world, is a landmark development in the annals of high dam building in India. Located in highly complex geo-tectonic environs of Himalayas-a region prone to high seismic activity, its safe design and construction, posed immense technical challenges. The paper describes in a nutshell, how these challenges have been adequately met by THDC, which the author believes, was possible, with human efforts being blessed by the mother river.

10 illus, 3 tables, 6 ref

002517   Jain M K;Sastry B S (NO, College of engineering, Guindy) : Hydraulic transportation of fly ash - a laboratory scale investigation. J Mines Metals Fuels 2006, 54(6-7), 135-41.

Flow behaviour of fly ash slurry is a very complex phenomenon. The study tries to examine the relation between flow rate all pressure loss of fly ash slurry under laboratory scale experimental set up in the light of available theoretical background. Pressure loss increases with the increase in flow rate and solid concentration but (5 -20%) pressure losses call be saved by addition of 2200 ppm concentration of polyacrylamide polymer.

7 illus, 4 tables, 6 ref

002516   Gusain M S;Sarwal D;Garg A K;Garg B K;Rana N S (NO, , Tehri Hydro Development Corporation Ltd. Rishikesh, Uttrakhand) : Development of Tehri hydro project - inception to commissioning. Wat Energy int 2007, 64(1), 3-13.

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