015131   Rao C G;Siddhartha J;Nerella U V P (Mechanical Engineering Dep, National Institute of Technology, warangai-506 004) : Parametric studies on multi-mode heat transfer from a rectangular slab with multiple discrete heat sources. J Instn Engrs-Pt MC 2010, 91(Oct), 31-8.

The present paper provides results of simulation studies on multi-mode heat transfer from a discretely heated rectangular slab. The slab is equipped with five flush-mounted discrete heat sources with identical rating and dimensions. Air, a radiatively non-participating medium, is considered as the cooling agent. The governing equations for temperature distribution in the entire slab are obtained by appropriate energy balance. The resulting nonlinear partial differential equations are converted into algebraic form using finite difference formulation and are subsequently solved with the help of Gauss-Seidel iterative solver. The effects of parameters, like surface emissivity, convection heat transfer coefficient and thermal conductivity, on local temperature distribution, peak slab temperature and relative contributions of convection and radiation are studied in detail.

11 illus, 3 tables, 10 ref

015130   Rana P S (HUDCO, , ) : Pricing of water for sustainability. Productivity 2009, 50(3), 218-25.

Meeting the needs of the growing population and urban development are two of the issues to be dealt with by public agencies in the Indian economy. This paper looks at how a proper infrastructure that supports this rising population, may be developed, specifically, with respect to the available water resources. It evaluates the various aspects of costing in relation to the demand of the households and presents the recommendations of the authorities in this regard.

4 illus, 8 tables, ref

015129   Ramana Murthy C V;Hari Prasad P (NO, Lakkireddy Balireddy College of Engineering, Mylavaram-521 230, Email: pergupallihari@yahoo.com) : Unsteady state MHD flow in a porous channel with an exponentially decreasing suction. Ultra Scient phys Sci 2010, 22(2), 337-46.

The unsteady state viscous incompressible and electrically conducting fluid through a porous channel when a transverse magnetic field is applied has been studied in this paper. The analysis has been carried out and best possible classical solution in a closed form has been obtained. The expressions for various flow entities are obtained, and the effect of critical parameters participating in the field equations have been presented analytically and illustrated graphically.

17 illus, 15 ref

015128   Rama Chandra Murthy A;Palani G S;Iyer N R (Structural Engineering Research Centre, CSIR Campus, Taramani, Chennai-600 113, Email: murthyarc@sercm.org) : State-of art review on fracture analysis of concrete structural components. Sadhana 2009, 34(2), 345-67.

Presents a critical review of literature on fracture analysis of concrete structural components. Review includes various fracture models, tension softening models, methodologies for crack growth analysis and remaining life prediction. The widely used fracture models which are based on fictitious crack approach and effective elastic crack approach have been explained. Various tension softening models such as linear, bi-linear, tri-linear, etc. have been presented with appropriate expressions. From the critical review of models, it has been observed that some of the models have complex expressions involving many parameters. There is a need to develop some more generalised models. Studies have been conducted on crack growth analysis and remaining life prediction using linear elastic fracture mechanics (LEFM) principles. From the studies, it has been observed that there is significant difference between predicted and experimental observations. The difference in the values is attributed to not considering the tension softening effect in the analysis.

13 illus, 4 tables, 97 ref

015127   Rajendra Prasad P;Sanjeevamurthy;Harish S (Mechanical Engineering Dep, SSIT, Tumkur, Karnataka) : Mechanical properties of woven vanana fiber reionforced Polypropylene composites. Ultra Scient phys Sci 2010, 22(2), 413-18.

The main objective of this paper is to analyze the fracture and flexural behavior of Polypropylene (PP)/woven banana fiber by experimental and finite element analysis (FEA). The laminates were prepared by using a proprietary hot press designed for the purpose. PP/ woven banana laminates with 0,2,4, 6 wt% of woven banana fiber were pressed at 220°C temperature and 4 MPa pressure in alternate layers of PP and woven banana fiber. The specimens were tested for tensile properties as per ASTM -638, flexural properties as per ASTM -790 M using 2-ton tensometer at a strain rate of 5 mm/min. The scanning electron microscopy showed superior stiffness and UTS compared with PP. The ply-by-ply behaviour of alternate PP and woven banana fiber layers subjected to tension and bending were studied by FEA to compare the FE predictions with the experimental results.

7 illus, 6 ref

015126   Raja A S M;Thilagavathi G (Textile Technology Dep, PSG College of Technology, Coimbatore-641 004) : Development of union fabrics using short fine wool yarn and cotton yarn. J Instn Engrs-Pt TE 2010, 90(Feb), 32-6.

An alternate value addition for short fine wool was done in this study. Two types of wool-cotton union fabric were produced using two different counts of wool yarns spun from short fine wool as weft and coloured cotton yams as warp. The woollen part of the fabrics was cross dyed using 1:2 metal complex dyes to uniform shade followed by finishing with a cationic softener. The performance of finished union fabrics were compared with the 100% wool control fabric to find their suitability as blankets for tropical winter season. The stiffness, linearity of compression (LC), resilience of compression (RC) and air resistance of the grey fabrics were improved by about 30%, 10%, 10% and 40%, respectively, due to better dyeing and finishing. The union fabrics showed 40% to 50% reduced felting shrinkage compared to 100% wool control fabric.

4 illus, 3 tables, 11 ref

015125   Pradhan S C;Murthy P V S N (Mathematics Dep, Indian Institute of Technology, Kharagpur-721 302) : Casson fluid flow through an elastic artery. J Instn Engrs-Pt MC 2010, 91(Oct), 3-9.

In the present work, flow of a pulsatile Casson fluid through a stenosed artery has been investigated. The artery'is assumed to be a cylinder of finite length and uniform diameter. Stenoses are considered to be present on top and bottom of the inner artery wall. Artery wall is assumed to be elastic in nature. The governing momentum equation is expressed in terms of the shear stresses. The momentum equation along with the initial and boundary conditions are solved numerically. Finite element analysis is employed and artery wall displacements are computed. The fluid solid interaction (FSI) and convergence study are carried out. Influence of the radial displacement of artery wall for the magnitude of artery wall stiffness have been investigated and the horizontal location of the stenoses.

7 illus, 22 ref

015124   Pandey A K;Venkatesh K P;Pratap R (Mechanical Engineering Dep, CranesSci MEMS Laboratroy, Indian Institute of Science, Bangalore-560 012, Email: pratap@mecheng.iisc.ernet.in) : Effect of metal coating and residual stress on the resonant Frequency of MEMS resonators. Sadhana 2009, 34(4), 651-61.

MEMS resonators are designed for a fixed resonant frequency. Therefore, any shift in the resonant frequency of the final fabricated structure can be a denting factor for its suitability towards a desired application. There are numerous factors which alter the designed resonant frequency of the fabricated resonator such as the metal layer deposited on top of the beam and the residual stresses present in the fabricated structure. While the metal coating, which acts as electrode, increases the stiffness and the effective mass of the composite structure, the residual stress increases or decreases the net stiffness if it is a tensile or compres-sive type respectively. In this paper, we investigate both these cases by taking two different structures, namely, the micro cantilever beam with gold layer deposited on its top surface and the MEMS gyroscope with residual stresses. First, we carry out experiments to characterize both these structures to find their resonant frequencies. Later, we analytically model those effects and compare them with the experimentally obtained values. Finally, it is found that the analytical models give an error of less than 10% with respect to the experimental results in both the cases.

7 illus, 5 tables, 13 ref

015123   Nieva P M;Kuo J;Chiang S H W;Syed A (Mechanical and Mechatronics Engineering Dep, Waqterloo Univ, 200 University Avenue West, Waterloo, N2L 3GI, Email: pnieva@uwaterloo.ca) : Novel MOEMS pressure sensor: modelling and experimental evaluation. Sadhana 2009, 34(4), 615-23.

Presents a novel MOEMS (Micro Opto Electromechanical Systems) pressure sensor suitable for localized precision measurements in high temperature environments. The sensor is based on a micromachined Fabry-Perot device (MFPD) that uses a thin film microcantilever beam as the top mirror and a silicon substrate as the bottom mirror of the optical microcavity. The major effect that the viscosity and density of the air surrounding the MFPD have on the viscous damping provides the mechanism for the detection of the pressure. A major advantage of this configuration is that there is no need for a sealed microcavity since the air is trapped by the viscous damping effects. The sensor has been tested up to 90 psi and pressure sensitivities of about 0.04%/psi with a MFPD sensor with a resonant frequency of about 46.7 kHz have been measured.

6 illus, 1 table, 10 ref

015122   Nagaraju C;Narayana Rao K;Mallikarjuna Rao K (Mechanical Engineering Dep, V R Siddhartha Engineering College, Vijaywada-520 007, Email: nagaraju_cherukuri@yahoo.co.in) : Application of 3D wavelet transforms for crack detection in rotor systems. Sadhana 2009, 34(3), 407-19.

The dynamics and diagnostics of a cracked rotor have been gaining importance in recent years. The early detection of faults like fatigue cracks in rotor shafts are very important to prevent catastrophic failure of the rotor system. Vibration monitoring during start up or shut-down is as important as during steady state operation to detect cracks especially for machines such as aircraft engines which start and stop quite frequently and run at high speeds. So, the transient data of the cracked rotor has been transformed using the wavelet transforms for crack detection. Most of the works quoted in the literature used 1D wavelets or 2D wavelets (Continuous Wavelet Transform-CWT) for crack detection. The crack detectors in the signals are both time as well as frequency dependent. So, the use of 2D wavelets is also not enough to detect the crack. In the present work a 3D wavelet (CWT) has been utilized which clearly indicates both the time and frequency features of the crack. The presence of sub-criticals in the CWT may be a best crack indicator but it is not always reliable. The addition of noise to the signal may sometimes lead to inaccurate results. So, there is a need to identify a parameter in addition to the sub-criticals. The phase angle between the two signals (cracked and un-cracked) or two transverse vibrations can be a better crack indicator because it is very less sensitive to noise disturbance. So, to extract the above phase angle a new transform has been applied called Cross Wavelet Transform (XWT). The XWT is exploited for the first time to a rotor fault detection system in the present work. Some interesting results have been obtained using the same. The advantage of the XWT is that both, the phase angles between the transverse signals and also the amplitudes of sub-criticals are viewed in a single plot. Parametric analysis is also carried out by varying crack depth and crack position for diagnostic purposes. The inverse problem of crack identification (i.e. determining the crack parameters through known vibration data) has also been carried out using Artificial Neural Network (ANN).

10 illus, 10 ref

015121   Muthukumar P;Umekar M M (Mechanical Engineering Dep, Indian Institute of Technology Guwahati, Guwahati0781 039, Email: pmkumar@iitg.ernet.in) : Coupled heat mass transfer during absorption of hydrogen in MmNi_4.6Al_0.4 based hydrogen storage device. Sadhana 2009, 34(2), 255-70.

A two-dimensional numerical analysis of coupled heat and mass transfer processes in a cylindrical metal hydride reactor containing MmNi_4.6Al_0.4 is presented. To understand the hydrogen absorption mechanism the governing equations for energy, momentum and mass conservation and reaction kinetic equations are solved simultaneously using the finite volume method (FVM). Performance studies on MmNi_4.6Al_0.4 based hydrogen storage device are carried out by varying the hydrogen supply pressure, absorption (cooling fluid) temperature, overall heat transfer coefficient and hydride bed thickness. Effect of convection terms in the energy equation on hydrogen storage performance is found to be negligible. The results obtained from the computer simulation showed good agreement with the available experimental data. At the supply conditions of 30 bar and 298 K, MmNi_4.6Al_0.4 stores about 1.28 wt%, which is very close to the experimental value of 1.3 wt%. Overall high heat transfer coefficients are found to reduce the absorption time significantly.

16 illus, 2 tables, 17 ref

015120   Meenakshi Reddy R;Nallusamy N;Hemachandra Reddy K;Ramachandra Reddy G (Mechanical Engineering Dep, Sri Venkateswara College of Engineering & Tech., Chittoor-517 127, Email: rmreddy123@gmail.com) : Investigation of the effect of PCM capsule material on the Thermal energy storage system. Ultra Scient phys Sci 2010, 22(1), 230-8.

To bridge the gap between supply and utilization of solar thermal energy storage (TES) systems are developed. The TES systems using both sensible and latent heat storage systems are gaining much attention because of its advantages like high energy storage in a unit volume and its isothermal behavior during the charging and discharging processes. The experimental investigation is done to analyze the effect of phase change material (PCM) capsule material on the performance of TES system during charging and discharging processes. The PCM capsules are spherical in shape and its outer diameter is 68mm. In the process of investigation the spherical capsules are made using three different materials viz. i) High Density Poly Ethylene (HOPE), ii) Aluminum (Al) and iii) Mild Steel (MS). The PCM material used in the experiments is paraffin (type II). The TES system is coupled with flat plate solar collector. The experimental investigation showed that the charging and recovery of storage energy is less affected by the spherical capsules material. The variables like charging time and discharging quantity are varied around 5% for the different capsule materials. Even though Aluminum thermal conductivity is much higher than HDPE and mild steel, its influence on performance of TES system is very less due to very high internal heat resistance of PCM material stored in the spherical capsules.

7 illus, 1 table, 11 ref

015119   Mansouri A;Aznaveh A M;Azar F T (Electrical and Computer Engineering Dep, Shahid Beheshti Univ, Tehran, 19839, Iran, Email: a_mansouri@shu.sc.ir) : SVD-based digital image watermarking using complex wavelet transform. Sadhana 2009, 34(3), 393-406.

A new robust method of non-blind image watermarking is proposed in this paper. The suggested method is performed by modification on singular value decomposition (SVD) of images in Complex Wavelet Transform (CWT) domain while CWT provides higher capacity than the real wavelet domain. Modification of the appropriate sub-bands leads to a watermarking scheme which favourably preserves the quality. The additional advantage of the proposed technique is its robustness against the most of common attacks. Analysis and experimental results show much improved performance of the proposed method in comparison with the pure SVD-based as well as hybrid methods (e.g. DWT-SVD as the recent best SVD-based scheme).

13 illus, 1 table, 29 ref

015118   Manoria A;Gajbhiya J;Verma P L;Bajpai L (Mechanical Engineering Dep, Samrat Ashok Technological Institute (Engineering College), Vidisha-464 001) : Optimizing rapid prototyping technlogy - replacing roller distribution system by pneumatic conveying system. J Instn Engrs-Pt MC 2010, 91(Oct), 27-30.

Great improvements are continuously being made in the solid freeform fabrication (SFF) industry in terms of processes and materials. Fully functional parts are being manufactured directly with minor finishing. Parts are being directly fabricated with engineering materials such as ceramics and metals. This paper aims to facilitate a substantial advance in rapid prototyping capabilities, in terms of fabricating parts with continuously heterogeneous material compositions. As SFF is an additive building process, building parts layer-by-layer or even point-by-point by adjusting material composition throughout the entire part, in all three dimensions, is feasible. The use of fine powders as its material of construction provides the potential for the selective laser sintering (SLS), three-dimensional printing (3DP), and freeform powder molding (FPM) processes to be altered to create continuously heterogeneous material composition. The objective of the study is to replace the current roller distribution system with a new means of delivering the powder that facilitates selective faster and heterogeneous-material compositions with less amount of time. This paper explores a pneumatic conveying deposition system that has the potential to deliver the powder in a controlled manner using a nozzle as in FDM and allow for adjustment of material composition throughout the layer and with lesser time than the existing roller system. The use of proposed method reduces the time to deposit material hence there is reduction in time taken to fabricate a component resulting overall cost reduction.

2 illus, 2 ref

015117   Mallik a K;Shivashankar S A;Biswas S K (Materials Research Centre, Indian Institute of Science, Bangalore-560 012, Email: amallik@cgcri.res.in) : High vacuum tribology of polycrystalline diamond coatings. Sadhana 2009, 34(5), 811-21.

Polycrystalline diamond coatings have been grown on unpolished side of Si(100) wafers by hot filament chemical vapour deposition process. The morphology of the grown coatings has been varied from cauliflower morphology to faceted morphology by manipulation of the growth temperature from 700°C to 900°C and methane gas concentration from 3% to 1-5%. It is found that the coeff-cient of friction of the coatings under high vacuum of 133.32 x 10^-7 Pa (10^-7 torr) with nanocrystalline grains can be manipulated to 0.35 to enhance tribological behaviour of bare Si substrates.

6 illus, 4 tables, 12 ref

015116   Madhekar S (PGAD, Defence Research and Development Organization, DRDL Complex, Kanchanbagh, Hyderabad-500 058, Email: suneel@ieee.org) : Cryptographic pseudo-random sequences from the chaotic Henon map. Sadhana 2009, 34(5), 689-701.

A scheme for pseudo-random binary sequence generation based on the two-dimensional discrete-time Henon map is proposed. Properties of the proposed sequences pertaining to linear complexity, linear complexity profile, correlation and auto-correlation are investigated. All these properties of the sequences suggest a strong resemblance to random sequences. Results of statistical testing of the sequences are found encouraging. An estimate of the keyspace size is presented.

6 illus, 5 tables, 24 ref

015115   Ma K;Chen L;Sun F (Postgraduate School, Naval Engineering Univ, Wuhan 430033, P.R. China, Email: lgchenna@yahoo.com) : Profit rate performance optimization for a generalized irreversible combined refrigeration cycle. Sadhana 2009, 34(5), 851-64.

Finite-time exergoeconomic performance of a Newtonian heat transfer law system generalized irreversible combined refrigeration cycle model with finite-rate heat transfer, heat leakage and internal irreversibility is presented in this paper. The operation of the generalized irreversible combined refrigeration cycle is viewed as a production process with exergy as its output. The performance optimization of the cycle is performed by taking profit as the objective. The optimal profit rate, optimal COP (coefficient of performance), as well as the relation between the optimal profit rate and COP of the cycle are derived. The focus of this paper is to obtain the compromise optimization between economics (profit rate) and the energy utilization factor (COP) for the cycle, by searching the optimum COP at maximum profit rate, which is termed as the finite time exergoeconomic performance bound. Moreover, the effects of various factors, including heat leakage, internal irreversibility and the price ratio, on the profit rate performance of the cycle are analysed by detailed numerical examples.

6 illus, 43 ref

015114   Krishnamoorthy P;Mahadev Prasanna S R (Electronics and Communication Engineering Dep, Indian Institute of Technology Guwahati, Guwahati-781 039, Email: pkm@iitg.ernet.in) : Application of combined temporal and spectral processing methods for speaker recognition under noisy, reverberant of multi-speaker environments. Sadhana 2009, 34(5), 729-54.

This paper presents an experimental evaluation of the combined temporal and spectral processing methods for speaker recognition task under noise, reverberation or multi-speaker environments. Automatic speaker recognition system gives good performance in controlled environments. Speech recorded in real environments by distant microphones is degraded by factors like background noise, reverberation and interfering speakers. This degradation strongly affects the per-formance of the speaker recognition system. Combined temporal and spectral pro-cessing (TSP) methods proposed in our earlier study are used for pre-processing to improve the speaker-specific features and hence the speaker recognition perfor-mance. Different types of degradation like background noise, reverberation and interfering speaker are considered for evaluation. The evaluation is carried out for the individual temporal processing, spectral processing and the combined TSP method. The experimental results show that the combined TSP methods give relati-vely higher recognition performance compared to either temporal or spectral pro-cessing alone.

8 illus, 6 tables, 40 ref

015113   Krishna Sarma G;Srinivas M (BS&H Dep, Vijay College of Engineering, (JNTU) Hyderabad-503 003, Email: gantikrish@yahoo.com) : Empirical approach of solar cells for maximum efficiency. Ultra Scient phys Sci 2010, 22(1), 179-82.

The mathematical modeling of the characteristics of solar cell materials by considering several factors like material properties, geometrical parameters, shape factors and other environmental variables is described in this paper. An equation based on certain assumptions to simulate the real operating conditions is formulated to the performance of a solar cell. The graphical plots for Carnot efficiency are obtained for different permutations and combinations to indicate the reasons for actual operating conditions, prevailing environmental conditions and also material properties of a solar cell.

4 illus, 18 ref

015112   Kathirvelu S;Souza L D;Dhurai B (Dhurai are with the Department of Textile Technology, Kumaraguru College of Technology, Coimbatore-641 006) : Overview of UV protection and evtion. J Instn Engrs-Pt TE 2010, 90(Feb), 26-31.

This review paper discusses the various aspects of solar UV radiation, such as, the harmful effects of prolonged exposure of humans to UV radiation, means of protection from the same by textile fabrics, and the test methods of the evaluation of the protection factors, such as, solar protection factor (SPF) and ultraviolet protection factor (UPF). Both in-vivo and in-vitro test methods of evaluation have been discussed in the present study along with a comparison between SPF and UPF values. The mechanism and factors of sun protection have been briefly dealt with. The standardized test methods currently in practice have been mentioned with their details of test condition influences.

^iia2 illus, 3 tables, 24 ref

015111   Kale N S;Joshi M;Nageswara Rao P;Mukherji S; Ramgopal Rao V (Electrical Engineering Dep, Indian Institute of Technology Bombay, Mumbai-400 076, Email: nsk@ee.iitb.ac.in) : Bio-functionalization of sillicon nitride-based piezo-resistive microcantilevers. Sadhana 2009, 34(4), 591-7.

Methods of bio-functionalize silicon nitride involve process steps to convert it into an oxynitride via plasma implantation techniques. Such methods can potentially damage microstructures such as cantilevers. In this paper, we report successful bio-functionalization of Hotwire CVD silicon nitride-based piezo-resistive cantilevers without any oxygen plasma treatment. Process to fabricate such structures and to bio-functionalize them is discussed in detail.

6 illus, 1 table, 6 ref

015110   Kalam M A etal (Mechanical Engineering Dep, Malaya Univ, 50603 Kuala Lumpur, Malaysia, Email: kalam@um.edu.my) : Development and test of a new catalytic converter for natural gas fuelled engine. Sadhana 2009, 34(3), 467-81.

Presents characteristics of a new catalytic converter (catco) to be used for natural gas fuelled engine. The catco were developed based on catalyst materials consisting of metal oxides such as titanium dioxide (TiO₂) and cobalt oxide (CoO) with wire mesh substrate. Both of the catalyst materials (such as TiO₂ and CoO) are inexpensive in comparison with conventional catalysts (noble metals) such as palladium or platinum. In addition, the noble metals such as platinum group metals are now identified as human health risk due to their rapid emissions in the environment from various resources like conventional catalytic converter, jewelers and other medical usages. It can be mentioned that the TiO₂/CoO based catalytic converter and a new natural gas engine such as compressed natural gas (CNG) direct injection (DI) engine were developed under a research collaboration program. The original engine manufacture catalytic conveter (OEM catco) was tested for comparison purposes. The OEM catco was based on noble metal catalyst with honeycomb ceramic substrate. It is experimentally found that the conversion efficiencies of TiO₂/CoO based catalytic converter are 93%, 89% and 82% for NO_x, CO and HC emissions respectively. It is calculated that the TiO₂/CoO based catalytic converter reduces 24%, 41% and 40% higher NO_x, CO and HC emissions in comparison to OEM catco respectively. The objective of this paper is to develop a low-cost three way catalytic converter to be used with the newly developed CNG-DI engine. Detailed review on catalytic converter, low-cost catalytic converter development characteristics and CNGDI engine test results have been presented with discussions.

13 illus, 3 tables, 26 ref

015109   Johal E;Jha M K;Saini M S (NO, , PTU-Jalandhar, Kapurthala Highway, Post bag No. 01, Kapurthala, Punjab, Email: Ejohal2001@yahoo.com) : Analysis of the characteristics of the leachate at Waryana Jalandhar (India). Ultra Scient phys Sci 2010, 22(1), 203-8.

Solid waste management has become a major environmental issue in India. India is generating approximately one lac tonnes of solid waste everyday of which 90% is dumped in the open place. The population growth and economic development has increased the municipal solid waste generation which in return generates Leachate. Leachate is the liquid that seeps from landfills and its quantity and quality depends mainly on the composition and types of solid waste dump along with many other factors like, moisture content, size, density, precipitation, land filling techniques etc. Leachate stream running directly into the aquatic environment have both acute and chronic impact on the environment which may be very serious and can severely diminish bio diversity and greatly reduce population of sensitive species. This paper is an attempt to deal with the studies which are carried out to investigate the amount of Total Solids (TS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Leachate Pollution Index (LPI), pH and different metal concentrations in the leachate sample of Waryana, Jaiandhar (Punjab) and are compared with the standard values.

1 illus, 1 table, 10 ref

015108   Jing G;Li M;Qin S;Lijie X;Li S (College of Chemistry and Chemical Engineering, Daqing Petroleum Institute, Daqing 163318, China, Email: jingguolin@yahoo.cn) : Use of nonionic and anionic surfactant in the treatment of oily sludge. Res J Chem Envir 2010, 14(1), 52-55.

Oily sludge, produced mostly in petroleum refineries and petrochemical industries, is one of the major industrial wastes that require treatment. The objective of this work was to recovery oil by washing of oily sludge with Nonionic and Anionic surfactant. To compare experimental results, three surfactants were used: sodium dodecylbenzene sulfonate (DBS), alkyl phenol polyoxyethylene ether (OP-10) and ethoxylation alkyl sodium sulfate (Na-AES). The oily sludge is studied in the laboratory and the composition of the oily sludge is analyzed by the weight method, the conditions of crude oil recovered are researched. Washing method can be implemented as a continuous method to reduce the amounts of waste oily sludge while recovering valuable fuel oil.

7 illus, 10 ref

015107   Jiang H;Gao X;Srivatsan T S (Mechanical Engineering De, The Akron Univ, Akron, Ohio-44325) : Enabling & understanding failure of engineering structures using the technique of cohesive elements. Int J Engng Sci Mgmt 2011, 1(1), 1-14.

Describes a cohesive zone model for the prediction of failure of engineering solids and/or structures. A damage evolution law is incorporated into a three-dimensional, exponential cohesive law to account for material degradation under the influence of cyclic loading. This cohesive zone model is implemented in the finite element software ABAQUS through a user defined subroutine. The irreversibility of the cohesive zone model is first verified and subsequently applied for studying cyclic crack growth in specimens experiencing different modes of fracture and/or failure. The crack growth behavior to include both crack initiation and crack propagation becomes a natural outcome of the numerical simulation. Numerical examples suggest that the irreversible cohesive zone model can serve as an efficient tool to predict fatigue crack growth. Key issues such as crack path deviation, convergence and mesh dependency are also discussed.

15 illus, 24 ref

015106   Jayswal S C (Mechanical Engineering Dep, M M M Engineering College, Gorakhpur-273 010) : Finite element analysis of magnetic abrasive finishing (MAF) process - a designed experiment. J Instn Engrs-Pt MC 2010, 91(Oct), 15-21.

Surface roughness plays an important role in product quality particularly in situations such as precision fits and high strength applications. Magnetic abrasive finishing (MAP) is relatively a new finishing process among the advanced finishing processes, which produces a high level of surface quality and is primarily controlled by magnetic field. In MAF, workpiece is kept between the two poles of a magnet. The working gap between the workpiece and the magnet isjtfled with magnetic abrasive particles. As a result, magnetic abrasive flexible brush (MAFB) is formed, acting as a multipoint cutting tool, due to the effect of magnetic field in the working gap. This paper deals with the theoretical investigations of MAF process. A finite element model of the process is developed to evaluate the distribution of magnetic forces on the workpiece surface. MAF process removes very small amount of material by indentation and rotation of magnetic abrasive particles in the circular tracks. In this investigation, a three factor two-level full factorial design is employed to perform a series of numerical experiments. The working gap, flux density and size of magnetic abrasive particles are taken as process variables. The results are employed to reveal the main effects as well as interaction effects of these three factors on surface quality.

9 illus, 4 tables, 14 ref

015105   Jayanna H S;Mahadeva Prasanna S R (Electronics and communication Engineering Dep, Indian Institute of Technology Guwahati, Guwahati-781 039, Email: j.jayanna,prasanna@iitg.ernet.in) : Experimental comparison of modelling techniques for speaker recognition under limited data condition. Sadhana 2009, 34(5), 717-28.

Most of the existing modelling techniques for the speaker recognition task make an implicit assumption of sufficient data for speaker modelling and hence may lead to poor modelling under limited data condition. The present work gives an experimental evaluation of the modelling techniques like Crisp Vector Quantization (CVQ), Fuzzy Vector Quantization (FVQ), Self-Organizing Map (SOM), Learning Vector Quantization (LVQ), and Gaussian Mixture Model (GMM) classifiers. An experimental evaluation of the most widely used Gaussian Mixture Model-Universal Background Model (GMM-UBM) is also made. The experimental knowledge is then used to select a subset of classifiers for obtaining the combined classifiers. It is proposed that the combined LVQ and GMM-UBM classifier provides relatively better performance compared to all the individual as well as combined classifiers.

2 illus, 7 tables, 17 ref

015104   Jacq C;Maeder T;Pyser P (Laboratorie de Production Microtecchnique, Ecole Polytechnique Federale de Lausanne, BM 3.142 - Station 17, CH-1015 Lausanne, Switzerland, Email: peter.ryser@epfl.ch) : Sensor and package based on LTCC and thick-film technology for severe conditions. Sadhana 2009, 34(4), 677-87.

Reliable operation in harsh environments such as high temperatures, high pressures, aggressive media and space, poses special requirements for sensors and packages, which usually cannot be met using polymer-based technologies. Ceramic technologies, especially LTCC (Low-Temperature Cofired Ceramic), offer a reliable platform to build hermetic, highly stable and reliable sensors and packages. This is illustrated in the present work through several such devices. The examples are discussed in terms of performance, reliability, manufacturability and cost issues.

16 illus, 25 ref

015103   Hema R (Information Technology Dronacharya College of Engineering Dep, College of Engineering, Khentawas, Gurgaon) : Comet, the reverse ajax mechanism. Int J Engng Sci Mgmt 2011, 1(1), 80-8.

Conventional web-based applications are all about client-led communication, but there has been a repeated need to discuss server-led communication within the web development community and to provide a name for it. To understand the phenomenon of Comet and Reverse Ajax, we need to consider why there is a need for it and why it is so out of the ordinary as to require a label of its own. In this paper we will discuss the business need for Re verse Ajax, limitation of HTTP protocol and techniques used to achieve Cornet.

2 illus, 18 ref

015102   Gupta V P (NO, UP, PWD, E-5 Chandra Apartment, Near-YojanaBhawan, 115, Kabir Marg, Lucknow-226 001, Email: vedpragupta@rediffmail.com) : Repair and improvement of damaged cement concrete pavement. Indian Highw 2009, 37(9), 47-50.

7 illus, 4 ref

015101   Govinda Raju S P (Aerospace Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: spg@aero.iisc.ernet.in) : Aerobasics-an introduction to aeronautics 13. the airplane structure. Resonance 2010, 15(3), 206-22.

The structure of an airplane holds it together in flight without significant deformation due to flight loads. It contributes to about a quarter of the airplane take-off weight. Any reduction in structure weight results in an equal increase in disposable load (fuel or payload) and thus con-1 tributes significantly to improved performance or economy. Thus great pains are taken by the designers to make an airplane structure as light as possible consistent with strength and stiffness. This structure is primarily of semi-monocoque design. This implies that it is designed as a hollow stiffened shell in which the skin contributes a major share to its strength and stiffness. In this article, we describe the general principles of design of this type of structure. We indicate the nature of flight loads the structure has to resist and the design concepts which ensure that the structure is safe during the life of an airplane.

10 illus, 1 table, 4 ref

015100   Givinda Raju S P (Aerospace Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: spg@aero.iisc.ernet.in) : Aerobasics - an introduction to aeronautics 12. safety in aviation. Resonance 2010, 15(1), 64-75.

Public awareness of airplane safety is very high due to the spectacular nature of airplane accidents. Partly as a result, civil airplane operations are tightly regulated at all levels from design to operation and maintenance. Scheduled airline operations have thus been able achieve a very high level of safety. In this article we quantify the safety of flight operations and indicate the design concepts like fail safety and safe life used in achieving a high level of safety. As an illustration, we consider the safety of a flight of a twin engine airplane in the event of one engine failure.

5 illus, 3 ref

015099   Giridhar M S;Jambhalikar A;John J;Islam R; Nagendra C L;Alex T K (Laboratory for Electro-Optic Systems, Thin Films and microsystems Group, Indian Space Research Organisation, 1st Stage, Peenya Industrial Estate, Bangalore-560 058, Email: giri@leos.gov.in) : X band MEMS switch based on silicon-on-glass architecture. Sadhana 2009, 34(4), 625-31.

Communication systems such as those used on satellite platforms demand high performance from individual components that make up the various systems and sub-systems. Switching and routing of RF signals between various modules is a routine and critical operation that determines the overall efficiency of the entire system. In this paper, we present the design and fabrication aspects of a direct contact RF MEMS switch designed to operate in the X band (8-12 GHz) with a target insertion of about 0.5 dB and isolation better than 30 dB. The actuation voltage is expected to be around 50 V. The die size is designed to be 3 mm (H) x 3 mm(W) x 2 mm(H). The switch is built from a low residual stress device layer of a highly conducting (0.005 Ohms-cm) silicon on insulator (SOI) wafer. After subsequent lithographic steps, the wafer is bonded to a Pyrex glass wafer which has been previously patterned with gold transmission lines and pull in electrodes. Being built from a single crystal silicon structure, the mechanical robustness of the actuator is much greater than the those in similar membrane-based devices. A 6 mask fabrication process utilizing Deep Reactive Ion Etching to achieve high aspect ratio stiction free structures was developed and implemented. Devices from the first fabrication run are being analysed in our laboratory.

5 illus, 1 table, 4 ref

015098   Ghosal A;Manna A;Lall A K (Mechnaical Engineering Dep, Dronachaya College of Engineering, Greater Noida, Email: er_ghosal@yahoo.co.in) : Fiber laser machining of 10 volume Al - AlO₂ composite material. Int J Engng Sci Mgmt 2011, 1(1), 50-6.

Non conventional machining processes have become popular today with compare to conventional machining process. In conventional machining processes so many problems may be arise like high pressure on work piece, tool failure, accuracy, surface finish etc. In nonconventional machining process like EDM, ECM, ECDM, LBM the above difficulties may be overcome. In this paper, some holes are drilled in A1-A1O₂ composites by 2 kW Ytterbium Fiber Laser and have been studied the characteristic of drilled holes for different parameters and a basic thermal modeling has also been done for various heat loosing process in the form of conduction, convection and radiation.

10 illus, 3 tables, 12 ref

015097   Gaur A;Manmohan Singh;Patil S B (Civil Engineering Dep, Malaviya National Institute of Technology, Jaipur) : Mechanical stabilzation of moorum using imperial smelting furnace (ISF) slag. Indian Highw 2009, 37(9), 29-34.

Moorum varying in their soil classification from CL, ML and GC based on unified soil classification are available locally within about 50 km of Jaipur. With a view to improve the strength characteristics of moorum and further enhance the strength of Imperial smelting Furnace (ISF) slag, it is considered appropriate to stabilize the moorum with ISF slag mechanically. Each set of mix proportions for each moorum and ISF slag were formulated. Each mix was tested for moisture-density relationship, plasticity index and CBR. The test results shows that on addition of ISF slag with moorum CBR value in each type of moorum slag mix increased. Increase in CBR is more in GC type of moorum slag mix than other two types of moorum slag mix. On addition of ISF slag with moorum of different type, plasticity index decreased in each type of moorum slag mix.

3 illus, 6 tables, 24 ref

015096   Dzwario B;Otieno Fred A O;Ochieng George M (Civil Engineering Dep, Tshwane Univ of Technology, Faculty of Engineering and the Built Envir, Private Bag X680, Pretoria, 0001, South Africa, Email: dzwairob@tut.ac.za) : Incorporating surface raw water quality into the cost chain for water services: Vaal catchment, South Africa. Res J Chem Envir 2010, 14(1), 29-35.

A mathematical model being used by the Department of Water Affairs (DWA) to analyse various environmental management options emphasises on total dissolved solids (TDS) as a water pollution indicator, to which pollution economic impacts are also related. Since its use, it has become apparent that water quality problems in the Vaal basin are much more complex and need a variety of other management measures. Furthermore, an initial focus on the imbalance between available water, growing demand and increasing river regulation has contributed towards elevated proportions of polluted return-flows to natural runoff. This has led to a decline in quality of water feeding the catchment as well as rising potable water treatment costs. Research being carried out in the Upper (upstream) and Middle (downstream) Vaal Water Management Areas (WMAs) bounded by Vaal dam outlet and Bloemhof dam inlet, aims at developing a multi-year tariff model for surface raw water of variable quality, in order to predict cost of treatment using historical data and compatible toolboxes on a Matlab platform.

4 illus, 5 tables, 15 ref

015095   Durairaj R;Mallik S;Seman A;Ekere N N (Faculty of Engineering and Science (FES), Tunku Abdul Rahman (UTAR) Univ, Jalan Genting Kelang, Setapak 53300 Kuala Lumpur, Malaysia, Email: rajkumar@utar.edu.my) : Investigation of wall-slip effect on lead-free solder paste and isotropic conductive adhesives. Sadhana 2009, 34(5), 799-810.

Slippage due to wall depletion effect is well-known in rheological investigation. The aim of this study was to investigate the influence of the paste microstructure on slip formation for the paste materials (lead-free solder paste and isotropic conductive adhesives). The effect of different flow geometries, gap heights and surface roughness on the paste viscosity was investigated. The utilisation of different measuring geometries has not clearly showed the presence of wall-slip in the paste samples. The existence of wall-slip was found to be pronounced when gap heights were varied using the parallel plate geometry. It was also found that altering the surface roughness of the parallel plate measuring geometry did not significantly eliminate wall-slip as expected. But results indicate that the use of a relatively rough surface helps to increase paste adhesion to the plates and to a certain extent inducing structural breakdown in the paste. Most importantly, the study also demonstrated on how the wall-slip formation in the paste material could be utilised for understanding of the paste microstructure and its flow behaviour.

4 illus, 3 tables, 13 ref

015094   Djuric N;Despotovic M (Faculty of Technical Sciences, Novi Sad Univ, Trg D. Obradovic 6, 21000 Novi Sad, Serbia, Email: ndjuric@uns.ns.ac.yu) : Application of MTR soft-decision decoding in multiple-head magnetic recording systems. Sadhana 2009, 34(3), 381-92.

Application of a simple approach for the soft-decision decoding of Maximum-Transition-Run (MTR) codes has been presented. A low-demanded hardware realization have been proposed for soft-decision decoding in MTR basic AND, OR and XOR logic circuits. The suggested approach is explored over the two-track, two-head E²PR4 partial response magnetic recording system. The overall two-track channel detection complexity reduction of 41.9% is offered in simulation scheme, encoded by Low-Density Parity-Check (LDPC) code, serially concatenated with inner MTR. The l.9dB coding gain has been obtained, comparing to uncoded channel and assuming the AWGN noise presence.

6 illus, 25 ref

015093   Diwakar N;Ahmed S;Sethi V K (Mechanical Dep, Truba Institut of Engineering and Information Technology, Bhopal-462 038) : Off-design performance prediction by mathematical modeling of 225 KW horizontal axis wind turbine rotor. Ultra Scient phys Sci 2010, 22(1), 1-12.

This paper present a compute based method of determining of off-design peek performance characteristics of horizontal axis wind turbine, new method based on analytical approach and an experimental verification based on reading taken from wind farm at Jamgodrani Dewas in Madhya Pradesh located at 76°10'E longitude and 22°59' N latitudes at the height of 560 m above mean sea level. The theoretical method of performance prediction is based different strip theory, in which a blade is divided into 100 radial elements. The blade chord, its twist and its elementary power co-efficient at each station were determined. The iterative process required for the convergence of speed interference factor and for maximization of power coefficient. The design process begins right at maximum power point, rather than searching of point of maximum power and then doing the computations. Analytical approach and an experimental verification of 225kW turbine come out 620.82 kWh and 487.56 kWh power generated respectively.

6 illus, 4 tables, 9 ref

015092   Devan P K;mahalakshmi N V (Mechanical Engineering Dep, Jerusalam College of Engineering, Chennai-600 100) : Development of bio-diesel from low fatty acid poon oil and evaluation of its performance and emission characteristics in a Dl diesel engine. J Instn Engrs-Pt MC 2010, 91(Oct), 10-4.

The present investigation describes the development of bio-diesel (methyl ester) from poon oil by alkaline transesterification using potassium hydroxide (KOH) as catalyst. Property analysis was carried out to ascertain the suitability of this methyl ester of poon oil. Ignition quality of methyl ester of poon oil was evaluated by means ofcetane index calculations according to the ASTM standard D976. The physical and chemical properties of methyl ester of poon oil were found to satisfy the requirements of Indian standards IS 1460-1974. Hence methyl ester of poon oil has been tried as a fuel for diesel engine. Performance and emission characteristics of a neat methyl ester of poon oil (MEPO) and its diesel blends were evaluated using naturally aspirated, direct injection diesel engine. The results show that the smoke, HC and CO emissions were reduced by 64.5%, 20% and 37% respectively for MEPO 40 blend and 58%, 32% and 31% respectively for MEPO 100. The brake thermal efficiency was increased by 1.6% for MEPO 40 blend. Based on the performance and smoke emission MEPO 40 blend was suggested as the fuel for diesel engines.

9 illus, 3 tables, 7 ref

015091   Das T;Chakraborty S (Biotechnology Dep, Indian Institute of Technology, Kharagpur-721 302, Email: suman@meh.iitkgp.ernet.in) : Biomicrofluidics: recent trends and future challenges. Sadhana 2009, 34(4), 573-90.

Biomicrofluidics is an active area of research at present, exploring the synergy of microfluidics with cellular and molecular biology, biotechnology, and biomedical engineering. The present article outlines the recent advancements in these areas, including the development of novel lab-on-a-chip based applications. Particular emphasis is given on the microfluidics-based handling of DNA, cells, and proteins, as well as fundamental microfluidic considerations for design of biomedical microdevices. Future directions of research on these topics are also discussed.

1 illus, 119 ref

015090   Das P;Bandyopadhyay M;Paul R;Baral K;Jha S N; Dan U;Banerjee A R (NO, , Lake Gardens Govt. Housing Estate, Flat No. I-7, 48/4 Sultan Alam Road, Kolkata-700 033) : Dyselectrolytemia as a predictor of outcome in patients with acute exacerbations of chronic obstructive pulmonary diseases. Indian med Gaz 2010, 144(7), 248-51.

Being one of the leading causes of mortality and morbidity, Chronic Obstructive Pulmonary Diseases (COPD) are gaining increasing public health importance around the world. Associated metabolic derangements often are the responsible factors for the fatal outcomes in COPD patients. In the present study we reviewed the clinical records of 64 patients of COPD admitted with acute exacerbations, in regards of their age, sex, total leukocyte count, ESR, serum electrolytes (sodium, potassium), number or days of hospital stay and ultimate outcomes (discharge after getting well or death). Significant proportion of patients (61%) were found to have lower than normal serum sodium (<60>135 mEq/lit) and significant negative correlations were found between serum sodium and total leukocyte count ('r'- value = -0.338, p <60>0.05) and total number of days of hospital stay (r'- value = -0.634, p <60>0.05). A significant proportion of patients (62.5%) were also found to have serum potassium below the normal reference level (<60>3.5 mEq/lit). Out of 64 patients, 7 persons died and 57 could be discharged after stabilization. All of the persons who died had a lower than normal serum sodium and potassium levels. Study concludes that hyponatremia and hypokalemia may be the common accompaniments during the acute exacerbations of COPD which may worsen the scenario if not corrected on time. Therefore, serum sodium and potassium levels should be meticulously monitored in every patient of acute episode of COPD and any derangements should be corrected promptly to avoid fatal outcomes.

2 tables,9 ref

015089   Das A (Civil Engineering Dep, National Institute of Technology, Durgapur-713 209, Email: adas_wrmp@yahoo.com) : Reverse stream flow routing by using muskingum models. Sadhana 2009, 34(3), 483-99.

Reverse stream flow routing is a procedure that determines the upstream hydrograph given the downstream hydrograph. This paper presents the development of methodology for Muskingum models parameter estimation for reverse stream flow routing. The standard application of the Muskingum models involves calibration and prediction steps. The calibration step must be performed before the prediction step. The calibration step in a reverse stream flow routing system uses the outflow hydrograph and the inflow at the end period of the inflow hydrograph as the known inputs and Muskingum model parameters are determined by minimiz-ing the error between the remaining portion of the predicted and observed inflow hydrographs. In the present study, methodology for parameter estimation is devel-oped which is based on the concept of minimizing the sum of squares of normalized difference between observed and computed inflows subject to the satisfaction of the routing equation. The parameter estimation problems are formulated as con-strained nonlinear optimization problem, and a computational scheme is developed to solve the resulting nonlinear problem. The performance evaluation tests indi-cate that a fresh calibration is necessary to use the Muskingum models for reverse stream flow routing.

3 illus, 6 tables, 15 ref

015088   Darling R B;Iwanaga S (Electrical Engineering Dep, Washington Univ, Box 352500, Seattle, WA 98195-2500 USA, Email: bruced@u.washington.edu) : Structure, properties, and MEMS and microelectronic applications of vanadium oxides. Sadhana 2009, 34(4), 531-42.

Vanadium oxides have for many decades attracted much attention for their rich and unique physical properties which pose intriguing questions as to their fundamental origins as well as offering numerous potential applications for microelectronics, sensors, and microelectromechanical systems (MEMS). This paper reviews the unique structure and properties of the two most common vanadium oxides which have entered into microfabricated devices, VO₂ and V₂O₅, and some of the past and future device applications which can be realized using these materials. Two emerging new materials, sodium vanadium bronzes and vanadium oxide nanotubes are also discussed for their potential use in new microelectronic devices.

6 illus, 31 ref

015087   Daga K;Patel D;Anil V (Enviro-Industrial Lab., Chemistry Dep, M.B.M. Engineering College, Jai Narain Vyas Univ, Jodhpur-342 033, Email: maildpatel@yahoo.com) : Low cost adsorbents for heavy metal removal from wastewater. Res J Chem Envir 2010, 14(1), 100-3.

The adsorption process is being widely used by various researchers for the removal of heavy metals from wastewater. In recent years the use of various natural products has been widely investigated as a replacement for the currently costly methods of treatment of wastewater. Some of the natural products can be effectively used as a low-cost adsorbent as well as low-cost sorbent. In this review, an extensive list of recent investigations and literature has been compiled to provide information on a wide range of low cost adsorbents and the treatment of wastewater using them.

^iia1 table, 31 ref

015086   Chollet F;Liu H B;Ashraf M;Thubthimthong B; Zhang X M;Hegde G;Asundi A;Murukeshan V M;Liu A Q (MicroMachines Centre, School of MAE, Nanyang Technological Univ, 50 Nanyang Avenue, 639798 Singapore, Email: franch.chollet@femto-st.fr) : Of light, of MEMS: optical MEMS in telecommunications and beyond. Sadhana 2009, 34(4), 599-606.

The burst of the Internet bubble in 2000 has severely quenched the pace of development in the optical MEMS field. However, it is now clear that this field is again set to move forward as not only telecommunication but many other industries are benefiting from its application. We describe in this paper some of our latest achievements in the field, showing a new type of small scale optical switch based on integrated optics, a vibration/acceleration sensor using a very-short external cavity laser and finally, the early development result of a nano-scale tunable photonic crystal that could be used for beam steering. The diversity of the applications we demonstrate, is a clear testimony that there is indeed 'plenty of room at the bottom'-and particularly in the natural combination of Light and MEMS.

10 illus, 18 ref

015085   Chauhan T;Bhagabati C D;Vinod Kumar (Electronics and Communication Dep, Dronacharya Collge of Engineering B-27 Knowledge Park-III, Greater Noida-201 306) : ERA of energy harnessing: μ-energy scavengers using microsystems (MEMS) Technology. Int J Engng Sci Mgmt 2011, 1(1), 75-9.

With rising crisis of energy and power in the new millennium the lookout for alternative and new sources of power is being done on a magnum scale. The paper introduces techniques that are capable of harvesting and scavenging μ-energy from ambient atmosphere such as light, heat or vibrations and also harvests power from sources such as human activity. Microsystems devices are a viable option due to size and feasibility of integrating these devices with the electronics. Some of the energy scavengers are introduced as examples.

7 illus, 1 table, 10 ref

015084   Chatterjee S;Alam S S;Misra R B (Applied Mathematics Dep, Indian School of Mines Univ, Dhanbad-826 302, Email: chatterjee_subhashis@rediffmail.com) : Sequential Bayesian technique: an alternative approach for software reliability estimation. Sadhana 2009, 34(2), 235-41.

Proposes a sequential Bayesian approach similar to Kalman filter for estimating reliability growth or decay of software. The main advantage of proposed method is that it shows the variation of the parameter over a time, as new failure data become available. The usefulness of the method is demonstrated with some real life data.

1 illus, 2 tables, 29 ref

015083   Chandra S;Bhatt V;Singh R (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, Hauz-Khas, New Delhi-110 016, Email: schandra@care.iitd.ernet.in) : RF sputtering: a viable tool for MEMS fabrication. Sadhana 2009, 34(4), 543-56.

Fabrication of Micro-Electro-Mechanical-Systems (MEMS) requires deposition of films such as SiO₂, Si₃N₄ ZnO, polysilicon, phosphosilicate glass (PSG), Al, Cr-Au, Pt, etc. for use as structural, sacrificial, piezoelectric and conducting material. Deposition of these materials at low temperature is desirable for fabricating sensors/actuators on temperature-sensitive substrates and also for integrating MEMS structures on silicon in post-CMOS processing procedures. Plasma enhanced chemical vapour deposition (PECVD) and sputtering are amongst potential techniques for preparing films for MEMS fabrication at comparatively low temperatures. The sputtering technique has an added advantage that the process is carried out in an inert ambient (argon) and chemically sensitive substrate/sacrificial layers can be used in realization of MEMS. Furthermore, the same system can be used for depositing dielectric, piezoelectric and conducting materials as per requirement in the fabrication sequence. This enables rapid low-cost prototyping of MEMS with minimum fabrication facilities. In the present work, we report preparation, characterization and application of RF sputtered SiO₂, Si₃N₄ and ZnO films for MEMS fabrication. The effect of RF power, sputtering pressure and target-to-substrate spacing was investigated on the structural and other properties of the films. The residual stress in the films was obtained using wafer curvature measurement technique. The deposition parameters are optimized to obtain low stress films of SiO₂ and Si₃N₄. The self-heating of the substrate during deposition was advantageously exploited to obtain highly c-axis oriented films of ZnO without any external heating. A variety of MEMS structures such as cantilever beams, micro-bridges, diaphragms, etc. are demonstrated using bulk, surface and surface-bulk micromachining techniques.

14 illus, 1 table, 16 ref

015082   Bhoomkar M M;Navale L G;Likhite P B (Mechanical Engineering Dep, Pune Vidyaarthi Griha's College of Engineering and Technology, Pune-411 009) : Optimization of plate process parameters to achieve WCM approach in small and medium scale offset printing industry. J Instn Engrs-Pt MC 2010, 91(Oct), 22-6.

In the present study, critical process parameters for offset printing have been considered that directly affect the product performance. It is well known that customer satisfaction is a key to successful business. The press authority must understand the elements of the processed, which can be measured, monitored and controlled. This analytical work is an attempt to understand the variation and control of the process parameters during production. The Mathematical model developed is used as a tool to optimize the plate coating thickness for minimum cost criteria so as to achieve the WCM approach in small and medium scale industry.

3 illus, 5 tables, 4 ref