013547   Anbalagan P (Economics Dep, Presidency College, Chennai-5, Email: pvanbalagan@yahoo.co.in) : Port connectivity and economic development: a study of the Tuticorin port in India. Indian Ports 2008, 39(3), 3-13.

Port connectivity is plays an important role in the logistic chain. Port connectivity with various modes was begain since the First Five Year Plan period in India, while a marked focus paid during Ninth and Tenth Plan periods. Road and port connectivity are very much important to the land locked regions for their socio-economic development. In order to strengthen the transport infrastructure the mega projects like, Golden Quadrilateral, North-South and East-West Corridor project and Sethusamudram Ship Channel Project (SSCP) are being executed in Indian. In addition to these, the individual port trusts also pay attention to connect with the rest of transport modes. Port-rail connectivity is another crucial aspect, which would ensure better performance of the ports. In order to strengthen the rail-port connectivity, National Rail VikasYojana (NRVY) was introduced in 2002. The main objective of NRVY is the enhancement of port connectivity to 1372 km and targeted to complete before 2008. The development of industry, agriculture and trade are positively associated with the transport sector. Reduction of cost of goods and services are depends on the efficient of transport sector, which has both backward as well as the forward linkages. In the Tuticorin port hinterland, rail and road network are the important modes connecting port. While the primary hinterland districts got more privilege from transport, many of the secondary hinterland districts are not directly connected with the port. It is very clear that the primary hinterland's economic development has significantly increased. In the secondary hinterland districts have comprehensive scope for economic development, while transport connectivity with the ort is a big bottleneck. Therefore, in order to eliminate this bottleneck, special component programme is required.

2 illus, 6 tables, 19 ref

013546   Akkus A (Mechanical Engineering Dep, Engineering Faculty, Cumhuriyet University, Sivas, 58140, Turkey) : Temperature distribution study in resistance spot welding. J scient ind Res 2009, 68(3), 199-202.

Presents effect of sheet thickness and current density on cooling speed and temperature distribution in resistance spot welding. Thicker sheets have higher temperatures in weld zones. Temperatures are higher in sheets having various thicknesses under higher weld current. Weld current is more effective than material thickness on cooling rate and temperature distribution.

013545   Agarwal P;Verma V K;Pandey A K (Electrical Engineering Dep, Indian Institute of Technology, Roorkee-247 667) : Performance evaluation of a self-commutating CSI-fed induction motor drive for different operating conditions. IETE J Res 2008, 54(4), 229-38.

Performance of a modified self-commutating CSI-fed induction motor drive is investigated. The mathematical model of the complete drive system is developed in the synchronously rotating d-q reference frame. Closed form mathematical expressions are developed for torque, phase voltage, efficiency, power factor, total loss, etc. The steady state performance curves of the drive are obtained for the different operating conditions and are discussed in detail. Experiments are also carried out to investigate the performance and compared with the analytical results.

15 illus, 12 ref

012643   Zembaty Z (NO, Opole University of Technology, 45-271 Opole ul. Mikolajczyka 5, Poland) : Spatial seismic excitations and response spectra. ISET J Earthquake Technol 2007, 44(1), 233-58.

Formal extensions of the response spectrum method to include spatial seismic effects are reviewed. Two approaches are described in detail: the first based on random vibrations of a simple oscillator under two-component excitation, and the second analyzing multi-column building seismic response. The subjective choice of these two complementing approaches aims at analyzing the phenomenon of spatial seismic vibrations of structures from a broader physical perspective of various wave types propagating among structural supports, with detailed random vibration sensitivity analysis of a simple structural system still included.

20 illus, 55 ref

012642   Zamani M (Technology and Engineering Dep, Yasouj Univ, Daneshjoo Avenue, Yasouj, Iran 75914, Email: mahdi@mail.yu.ac.ir) : General model for the analysis of the rock slope stability. Sadhana 2008, 33(4), 433-41.

The slope stability analysis has many applications in the engineering projects such as the dams, the roads and open pits structures. The method of analysis is usually based on the equilibrium conditions of the potential plane and wedge failures. The zone of the potential failure is stable whenever the stability forces dominate instability characteristics of the slope. In most of the classic methods of slope stability analysis, the joint surfaces are assumed to be continuous along the potential failure zone. These can cause an underestimated solution to the analysis. In this research the joint trace length is considered to be discontinuous across the potential surface of failure as it happens in nature. Therefore, there exists a rock bridge between the local joint traces. Because of the numerous problems related to the rock slope stability the above assumption is satisfied and the shear strength characteristics of intact rock have taken part in the analysis. The analysis presented gives a better concept, view, and idea of understanding the physical nature of rock slopes and includes more parameters governing the stability of the potential failure zone.

8 illus, 1 table, 7 ref

012641   Yongxian D;Changjing X;Shunshan F;Zhiyu S (State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China) : Numerical analysis on protecting performance of layered arch structures subjected to blast loading. Def Sci J 2009, 59(2), 131-6.

Dynamic responses of layered arch structure composed of different materials subjected to blast loading are analysed by numerical simulation. The deflection, the particle velocity and the particle acceleration of the arch inwall and stress curves versus time are obtained comparing properties of blast resistance of different arch structures with the same amount of charge. The results show that the arch structure composed of foam concrete-SFRC-steel has good blast resistance. Furthermore, the dynamic performance of the foam concrete-SFRC-steel composite structures is studied with different amount of charge. Additionally, coupling relationship of blast resistance and explosion charge is analysed. Comparison of numerical results with experimental result's, show that they are in good agreement. This numerical analysis may provide important guidance for blast-resistanl design and analysis of underground structures.

11 illus, 5 tables, 12 ref

012640   Yesilce Y;Demirdag O;Catal S (Civil Engineering Dep, Dokuz Eylul Univ, 35160, Buca, Izmir, Turkey, Email: yusuf.yesilce@deu.edu.tr) : Free vibrations of a multi-span timoshenko beam carrying multiple spring-mass systems. Sadhana 2008, 33(4), 385-401.

Structural elements supporting motors or engines are frequently seen in technological applications. The operation of a machine may introduce additional dynamic stresses on the beam. It is important, then, to know the natural frequencies of the coupled beam-mass system, in order to obtain a proper design of the structural elements. The literature regarding the free vibration analysis of Bernoulli-Euler single-span beams carrying a number of spring-mass system and Bernoulli-Euler multi-span beams carrying multiple spring-mass systems are plenty, but on Tim-oshenko multi-span beams carrying multiple spring-mass systems is fewer. This paper aims at determining the natural frequencies and mode shapes of a Timo-shenko multi-span beam. The model allows to analyse the influence of the shear effect and spring-mass systems on the dynamic behaviour of the beams by using Timoshenko Beam Theory (TBT). The effects of attached spring-mass systems on the free vibration characteristics of the 1-4 span beams are studied. The natural frequencies of Timoshenko multi-span beam calculated by using secant method for non-trivial solution are compared with the natural frequencies of multi-span beam calculated by using Bernoulli-Euler Beam Theory (EBT) in literature; the mode shapes are presented in graphs.

10 illus, 6 tables, 24 ref

012639   Yagiz K;Emir Sakman L;Guclu R (Mechanical Engineering Dep, Istanbul Univ, Avcilar, Istanbul, Turkey, Email: guclu@yildiz.edu.tr) : Different control applications on a vehicle using fuzzy logic control. Sadhana 2008, 33(1), 15-25.

In this paper, the active suspension control of a vehicle model that has five degrees of freedom with a passenger seat using a fuzzy logic controller is studied. Three cases are taken into account as different control applications. In the first case, the vehicle model having passive suspensions with an active passenger seat is controlled. In the second case, active suspensions with passive passenger seat combination are controlled. In the third case, both the passenger seat and suspensions have active controllers. Vibrations of the passenger seat in the three cases due to road bump input are simulated. At the end of the study, the results are compared in order to select the combination that supplies the best ride comfort.

6 illus, 1 table, 17 ref

012638   Ventura C E;Blazquez R (Civil Engineering Dep, The University of British Columbia, Vancouver, B.C., Canada) : Effect of system initial conditions on seismic design of long-period structures. ISET J Earthquake Technol 2007, 44(1), 111-26.

Initial conditions for the computation of response spectra are unknown in the case of analog earthquake records that have lost the initial portion of motion and are assumed to be zero for calculation purposes. This assumption, rigorously speaking, is only valid for high-frequency systems, such as rigid structures. Both rigid and flexible structures are sensitive to the initial conditions of the motion. The spectral values for long-period, elastic or inelastic systems tend to be particularly sensitive to the initial conditions of motion. Unconservative designs of long-period structures may result if the initial condition effects are not properly accounted for. Two practical methods are developed to approximate the true "non-resting" response spectra from the conventional ones for a given set of initial conditions. As expected, these conditions clearly control the free-vibration part of the response of long-period systems, as opposed to short-period systems which are governed by the transient phase of the response.

13 illus, 16 ref

012637   Uthayakumar M;Prabhaharan G;Aravindan S; Sivaprasad J V (Production Engineering Dep, National Institute of Technology, Tiruchirappalli, Email: uthaykumar@gmail.com) : Aluminum alloy piston reinforced with cast iron insert. Int J mathl Sci 2008, 3(1), 1-10.

Owing to the requirements such as light weight and high strength, especially in automotive sector, the use of reinforcement of heavy metals in the matrix of light metals is increasing. Piston being most demanding automotive component in terms of required strength to operate at elevated temperatures as well as at very high peak loads consists of an aluminum -silicon light alloy reinforced with a cast iron based insert. It is manufactured by gravity die casting process owing to the requirement of complicated inner shapes. Present work is focused on such a bi metal piston reinforced with a cast iron insert for harnessing the advantages of both the materials. In order to achieve a metallurgical bonding between aluminum and cast iron, the automotive piston fabricated with cast iron insert were subjected to heat treatment procedures. The mechanical and metallurgical characteristics of fabricated and heat treated pistons were studied through X-Ray diffraction (XRD), Hardness survey, Scanning Electron Microscopy (SEM) and Shear strength testing.

8 illus, 3 tables, 12 ref

012636   Uppu N;Subrahmanyam B V S S;Garimella R (Communication and Research Center, International Institute of Information Technology, Room No. 331, IIT-H, Gachibowli, Hyderabad-500 032) : Energy efficient technique to prolong network life time of ad hoc sensor networks [ETPNL]. IETE Tech Rev 2008, 25(4), 154-60.

Main objective of the study is to achieve prolonged network lifetime with overall energy efficiency in ad hoc sensor networks through controlled utilization of limited energy. In wireless sensor networks, most of the energy spent is consumed in routing the sensed data from cluster head to the base station. Optimizes the clustering and routing techniques. Introduces Backup heads (to avoid frequent re-clustering) in each cluster, Secondary membership heads (to eliminate multiple/redundant transmissions) and Optimum distance hoping to achieve overall energy efficiency of the network. A modification to existing clustering technique, in combination with our energy-efficient routing technique (using secondary memberships), results in large increase in the overall network lifetime. Use of secondary memberships (to route the data through shortest path) conserves more energy than that of the extra energy spent (for backup heads) in clustering. This results in overall energy efficiency with prolonged network lifetime.

9 illus, 3 tables, 11 ref

012635   Ullah A;Ikram N;Salam A (Centre of Excellence in Solid State Physics, University of the Punjab, Lahore, Pakistan) : Improvement in tensile properties of a structural steel by heat treatment. Int J mathl Sci 2008, 3(1), 89-94.

In order to improve the tensile properties of a 0.38 % structural steel, it was subjected to Water quenching after austenitizing, followed by tempering in the temperature range 200 C to 700 C. The steel was also normalized and oil quenched after austenitizing. In the normalized condition, the steel exhibited maximum toughness but a lower strength as compared to oil quenched conditions. The strength of the steel was found to increase even further when water quenched and tempered at 300 °C and 400 °C. However, a small decrease in ductility and toughness also accompanied.

5 illus, 2 tables, 6 ref

012634   Thirumarimurugan M;Kannadasan T;Ramasamy E (Chemical Engineering Dep, Coimbatore Institute of Technology, Coimbatore) : Heat exchangers using miscible system. Process Pl Engng 2007, 25(3), 53-9.

An experimental investigation on comparative heat transfer study on a solvent and solution were made using Cross flow and Shell and Tube Heat Exchangers. Steam is the hot fluid, whereas Water and Acetic acid - Water miscible solution serves as cold fluid. A series of runs were made between steam and water, steam and Acetic acid solution. In addition to, the volume faction of Acetic acid was varied and the experiment was held. The flow rate of the cold fluid is maintained from 30 Iph to 300 Iph for Cross flow Heat Exchanger, for Shell and Tube Heat Exchanger maintained from 120 lph to 720 Iph, and the volume fraction of Acetic acid is varied from 10% - 50%. Experimental results such as exchanger effectiveness, overall heat transfer coefficients were compared for both the How systems of Cross flow and Shell and Tube Heat Exchangers. A steady state model for the outlet temperature of both the cold and hot fluid and overall heat transfer coefficient of a plate-fin cross flow heat exchanger for Acetic acid solution- steam system at various compositions of Acetic acid is developed and simulated using MATLAB, which was verified with the experiments conducted. A mathematical model was developed for the outlet temperatures of both the Shell and Tube side fluids, and was simulated using MATLAB program. The model was compared with the experimental findings and found to be valid.

4 illus, 8 tables, 22 ref

012633   Thangal S U M;Pandey K S;Natarajan C; Shanmugam S (Metallurgical and Materials Engineering Dep, National Institute of Technology, Tiruchirappalli-620 015, Email: mtk0301@nitt.edu ) : Ring fracture strength and hardness in sintered-hot deformed high carbon steel preforms. Int J mathl Sci 2008, 3(1), 75-88.

Investigation pertains to studying the effect of fractional theoretical density and heights-to-diameter ratio on radial crushing strength for sintered-hot deformed Fe-0.8%C powder metallurgy ring preforms. In addition, an effect of 1.0% molybdenum addition in eutectoid steel ring preforms is highlighted. Rings of predetermined geometry were machined from the hot deformed preforms of different initial densities. It has been found that increasing initial density of the preform increases the radial crushing strength irrespective of preform geometry and compositions. Further, it has been observed that the hardness values are continuously increasing with increasing fractional theoretical density, also increasing height to diameter ratio substantially increases the hardness values for any theoretical density attained. It is also observed from fractographs that majority of the rings crushed in a highly brittle manner.

16 illus, 17 ref

012632   Srivastava H B;Vinod K;Verma H K;Sundaram S S (Instrument Research & Development Establishment, , Dehradun-248 008) : Image pre processing algorithms for detection of small/point airborne targets. Def Sci J 2009, 59(2), 166-74.

The problem of detecting small/point targets in infra-red imagery is an important research area for defence applications. The challenge is to achieve high sensitivity lor detection of dim point like small targets with low false alarms and high detection probability. To detect the target in such scenario, pre-processing algorithms are used to predict the complex background and then to subtract predicted background from the original image. The difference image is passed to the detection algorithm to further distinguish between target and background and/or noise. The aim of the study is to fit the background as closely as possible in the original image without diminishing the target signal. A number of pre-processing algorithms (spatial, temporal and spatio-temporal) have been reported in the literature. A survey of different pre-processing algorithm is presented. An improved hybrid morphological filter, which provides high gain in signal-to-noise plus clutter ratio (SCNR). has been proposed for detection of small/point targets.

^iia6 illus, 1 table, 36 ref

012631   Srinikethan G;Shrihari;Pradeepan V S (Chemical Engg Dep, NITK, Surathkal, Karnataka) : Optimum size of granite filter media for the maximum treatment of domestic sewage in upflow anaerobic biofilters. Pollut Res 2008, 27(2), 273-8.

Laboratory studies were conducted to assess the influence of media related factors such as particle size, porosity, pore size and specific surface area on performance of upflow anaerobic biofilters (AnBFs). Three simple models of 8 litres capacity upflow anaerobic biofilters (AnBFs) packed with support media granite of size 40 mm, 20 mm and 10 mm respectively were installed. The experimental anaerobic biofilters (AnBFs) were made of PVC tubes. The hydraulic retention time (HRT) was maintained as 12 hours. The study was carried out for a period of 90 days. The waste treatment performance indicates that the anaerobic biofilter (AnBF-2) packed with granite media of moderate particle size of 20mm demonstrated the highest BOD and COD removal 91.02 % and 82.01 % respectively.

2 illus, 3 tables, 14 ref

012630   Sivaji Babu K;Mohana Rao K;Rama Chandra Raju V;Bala Krishna Murthy V;Niranjan Kumar M S R (Mechanical Engineering Dep, V R Siddhartha Engineering College, Vijayawada-520 007, Email: k_sivajibabu@rediffmail.com) : Micromechanical analysis of FRP hybrid composite lamina for in-plane transverse loading. Indian J Engng Mater Sci 2008, 15(5), 382-90.

Micromechanical behaviour of the square unit cell of a hybrid fiber reinforced composite lamina consisting of graphite and boron fibers embedded in epoxy matrix, has been studied. A three-dimensional finite element model with governing boundary conditions has been developed from the unit cells of square pattern of the composite to predict the Young's modulus (E₂) and Poisson's ratios (?₂₁ and ?₂₃) of graphite-boron hybrid fiber reinforced lamina for various volume fractions. The stresses at the fiber-matrix interfaces induced due to the in-plane transverse loading, that is applied to predict the in-plane transverse Young's modulus (E₂) and the associated Poisson's ratios, are also determined from these models. The finite element software ANSYS has been successfully executed to evaluate the properties and stresses. The variation of the stresses at the fiber-matrix interface with respect to the angular location is discussed. The Young's modulus is found to be increasing with V_f indicating that the stiffness of the composite increases with V_f. The magnitude of the normal stresses at the fiber matrix interface are maximum at θ = 0° as the direction of the load is normal to the surface at this location. This may result in the separation of fiber and matrix leading to debonding. This analysis is useful to realize the advantages of hybrid fiber-reinforced composites in structural applications, and to identify the locations with reasons where the stresses are critical to damage the interface.

20 illus, 1 table, 16 ref

012629   Simha K R Y;Pottirayil A;Menezes P L;Kailas S V (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: simha@mecheng.iisc.ernet.in) : Friction tensor concept for textured surfaces. Sadhana 2008, 33(3), 203-6.

Directionality of grinding marks influences the coefficient of friction during sliding. Depending on the sliding direction the coefficient of friction varies between maximum and minimum for textured surfaces. For random surfaces without any texture the friction coefficient becomes independent of the sliding direction. This paper proposes the concept of a friction tensor analogous to the heat conduction tensor in anisotropic media. This implies that there exists two principal friction coefficients μ _1,2 analogous to the principal conductivities k_1,2. For symmetrically textured surfaces the principal directions are orthogonal with atleast one plane of symmetry. However, in the case of polished single crystalline solids in relative sliding motion, crystallographic texture controls the friction tensor.

3 illus, 12 ref

012628   Sheeba K N;Sarat Chandra Babu J;Jaisankar S (Chemical Engineering Dep, National Institute of Technology, Tiruchirappalli-620 015, Email: id:sheeba@nitt.edu) : Experimental analysis of coir pith for biomass fluidization: a preliminary study on the hydrodynamics of coir pith-sand system. Pollut Res 2008, 27(2), 309-13.

Gasification of biomass offers the best possible solution for the conversion of biomass to useful energy in an eco friendly manner, because no new addition of carbon dioxide is generated while burning biomass. Fluidization characteristics of a circulating fluidizing bed gasifier have been experimented with varying mixing ratios of biomass (coir pith) and sand. The total weight of the biomass-sand mixture is kept constant throughout the experiment. The experimentation is carried out for varying biomass particle sizes such as 241,360,450 and 520 urn. The particle size of the sand is 211 μm. The percentage of sand varies from 2%-12% with an increment of 2%. The velocity profile and the pressure drop profile for the fluidizing column are studied. Graphs are plotted between the superficial gas velocity and the pressure drop for both fluidization and defluidization characteristics. The minimum fluidization velocity for the biomass sand mixture is determined using the formula cited in the literature and is compared with the experimental data. The theoretical values are found to agree well with the experimental values (Re<20). The deviation between experimental and theoretical minimum fluidization velocities is within ±15%.

6 illus, 15 ref

012627   Shankara A;Menezes P L;Simha K R Y;Kailas S V (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: lancy@mecheng.iisc.ernet.in) : Solid lubrication with MoS₂ coating in the presence of additives using reciprocating ball-on-flat scratch tester. Sadhana 2008, 33(3), 207-20.

Molybdenum disulphide (MoS2) based solid lubricant mixtures containing zirconia and graphite were prepared in the laboratory and coated on steel specimens. The experiments were done using reciprocating scratch test for various numbers of cycles. The results showed that the addition of zirconia and graphite into the MoS₂ lubricant has improved its properties in terms of both friction and wear. In addition, it was observed that the presence of moisture affects the life of the lubricating film. It was shown that at high temperature the moisture evaporation enhanced the coating performance of the film.

9 illus, 28 ref

012626   Shamsul J B;Nur Hidayah A Z;Ruzaidi C M (School of Materials Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian 2 Taman Muhibbah, Jejawi, 02600 Arau, Perlis Malaysia, Email: sbaharin@unimap.edu.my) : Fabrication and properties of cobalt-chromium-HAP composite. Int J mathl Sci 2008, 3(1), 25-31.

Great demands exist for more efficient in artificial bone implant design to replace or repair existing fracture or damage bone. Alloys are the established materials that have been used and studied in surgical implant application due to it durability and low wear resistance. Conventional method in fabrication of implant application normally adopted casting technique. However, this technique has limitation due to high melting point to achieve. Alternatively, implant alloys fabricated by using powder metallurgy technique. Besides, this technique also can control porosity and provide better mechanical properties. In this paper, the fabrication process of cobalt implant composite (CIC) using powder metallurgy technique is described and the material properties of CIC are identified. From the observation, increasing weight percent of hydroxyapatite (HAP) will affect the hardness and density properties of the cobalt implant composite, which will decrease the hardness value and same result for the density measurement and compressive strength of the CIC.

7 illus, 4 ref

012625   Selva Raj A (NO, Indian Engg. College, Vadakkankulam, Nellai Dist., Tamil Nadu) : Optimum use of wind energy in windmills. Process Pl Engng 2007, 25(3), 71-2.

3 illus, 1 ref

012624   Sasi B;Rao B P C;Jayakumar T;Baldev Raj (NO, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Development of eddy current test procedure for non-destructive detection of fatigue cracks and corrosion in rivets of air-intake structures. Def Sci J 2009, 59(2), 106-12.

Non-destructive detection of defects in countersunk of rivets in multi -layer air -in take structures is essential for ensuring structural integrity and flight safety. This paper presents an eddy current test procedure developed for reliable detection of simulated fatigue cracks and corrosion products in rivets of air-intake structures. This procedure is capable of reliably delecting 0.25 mm deep defects in 4 mm dia rivets and 0.75 mm deep defects in 5 nun dia rivets. Further, it is not influenced by thickness of the multilayers.

10 illus, 10 ref

012623   Saran Ram;Srivastava H B;Ashok Kumar (NO, Instruments Research and Development Establishment, Dehradun-248 008) : Median predictor-based lossless vedeo compression algorithm for IR image sequences. Def Sci J 2009, 59(2), 183-8.

Lossless image compression has long been recognised as an important need for several applications such as medical imaging, storage of critical IR image sequences, and remote sensing. A simple, fast and easy to realisable-on-hardware lossless video compression algorithm is proposed that is well-suited for IR imageries. Context-based median predictor is used for prediction of reference pixels. Three neighboring pixels are used as context for prediction. Inter-frame coding is performed by encoding the redundant pixels in an efficient way, using 1-bit code. Finally, the arithmetic coder is used as entropy coding. The proposed algorithm is able to operate in image compression and video compression mode. The proposed Median Predictor based Lossless Video Compression (MPLVC) algorithm is compared with Joint Pictures Experts Group-Lossless (JPEG-LS) and Fast and Efficient Lossless Image Compression System (FELICS) for compression performance. The results demonstrate that proposed algorithm is superior in encoding rate with added advantage in simplicity and ease in realization on hardware.

7 illus, 2 tables, 12 ref

012622   Sanghavi V D (NO, , Aarvi Encon Pvt. Ltd., Mumbai) : Disaster prevention in petrochemical industry. Process Pl Engng 2007, 25(3), 50-2.

Disaster as a sudden and great misfortune or calamity or complete failure. Disaster can occur in any walk of life, without giving any or adequate notice. Chances of disaster occuring in petrochemical industry are higher because of many factors like reaction of petrochemicals with air, water, basic hazardous nature of chemicals and little known properties of petrochemicals at different pressures and temperatures to operating staff. It is responsibility of all concerned to prevent disaster. It is a team effort of Manager, Designers, Operators, Maintenance staff, Security personnel.

ref

012621   Sahu P C;Chandra Shekar N V (Materials Science Div, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, Email: pcsahu@igcar.gov.in) : High pressure research on materials. Resonance 2007, 12(8), 49-64.

Various experimental techniques for investigating materials under high pressure are discussed. The effect of pressure on the behaviour of materials is discussed with suitable examples.

19 illus, 5 ref

012620   Sahoo P;Mohamed Ali S (Mechanical Engineering Dep, Jadavpur Univ, Kolkata-700 032, Email: psahoo@vsnl.net) : Elastic-plastic adhesive contact of non-Gaussian rough surfaces. Sadhana 2008, 33(4), 367-84.

Describes an analysis of adhesion at the contact between non-Gaussian rough surfaces using the Weibull distribution with skewness as the key parameter to characterize asymmetry. The analysis uses an improved elastic-plastic model of contact deformation that is based on accurate Finite Element Analysis (FEA) of an elastic-plastic single asperity contact. Large range of interference values is considered starting from fully elastic through elastic-plastic to fully plastic regime of contacting asperities. The well-established elastic and plastic adhesion indices are used to consider the different conditions that arise as a result of varying load and material parameters. The loading and unloading behaviour for different combinations of the adhesion indices and skewness values are obtained as functions of mean separation between the surfaces. Transitional values of adhesion indices and skewness at which the influence of surface forces becomes insignificant are found to depend on material and surface parameters. Comparison with studies using previous elastic-plastic model that was based on some arbitrary assumptions shows significant differences in loading behaviour.

5 illus, 1 table, 35 ref

012619   Sabouri M;Shahrabi T;Salasi M (Corrosion & Protection Research Laboratory, Materials Science and Engi, Torbiat Madares Univ (TMU), Tehran, Iran, Email: msabouri@lycos.com) : Influence of phosphate ion dopants in corrosion protection properties of polypyrrole coating on mild steel. Int J mathl Sci 2008, 3(1), 33-46.

Polypyrrole (PPy) and polypyrrole-phosphate (PPy -PO₄^3- ) coatings were electrodeposited on mild steel electrodes from aqueous oxalic acid solution using cyclic voltammetry (CV) technique. Electrodeposition of PPy - PO^3-₄ was carried out with addition of tri-sodium phosphate dehydrate compound to the supporting electrolyte. The obtained coatings were characterized using scanning electron microscopy (SEM) and line-scan EDX techniques. In addition, comparison between their abilities to control corrosion of mild steel were done with application of open circuit potential (OCP) monitoring, polarization and electrochemical impedance spectroscopy (EIS) methods in 3.5% NaCl solution. Corrosion studies indicate that phosphate dopants can improve corrosion protection properties by taking part in: (i) the passivation processes occurred prior to electrodeposition processes, (ii) the electrosynthesis processes and incorporation into the polymer chain.

7 illus, 2 tables, 22 ref

012618   Reddy R M;Rao B N (Structural Engineering Div, Civil Engineering Dep, Indian Institute of Technology, Madras, Chennai-600 036, Email: bnrao@iitm.ac.in) : Calculation of derivatives of stress intensity factors using fractal finite element method. Indian J Engng Mater Sci 2008, 15(5), 391-418.

Presents a new fractal finite element based method for continuum-based shape sensitivity analysis for a crack in a homogeneous, isotropic, and two dimensional linear-elastic body subject to mixed-mode (modes I and II) loading conditions. The method is based on the material derivative concept of continuum mechanics, and direct differentiation. Unlike virtual crack extension techniques, no mesh perturbation is needed in the proposed method to calculate the sensitivity of stress-intensity factors. Since the governing variational equation is differentiated prior to the process of discretization, the resulting sensitivity equations predict the first-order sensitivity of the stress-intensity factors, K_I and K_II, more efficiently and accurately than the finite-difference method. Unlike the integral based methods such as J-integral or M-integral no special finite elements and post-processing are needed to determine the first-order sensitivity of the stress-intensity factors, K_I and K_II. Also a parametric study is carried out to examine the effects of the similarity ratio, the number of transformation terms, and the integration order on the quality of the numerical solutions. One mixed mode numerical example is presented to calculate the first-order derivative of the stress-intensity factors. The results show that the first-order sensitivities of the stress intensity factors obtained using the proposed method are in excellent agreement with the reference solutions obtained using the finite-difference method.

9 illus, 12 tables, 51 ref

012617   Rashmi Kumari;Gupta V K (Civil Engineering Dep, Indian Institute of Technology Kanpur, Kanpur-208 016) : Modal combination rule for peak floor accelerations in multistoried buildings. ISET J Earthquake Technol 2007, 44(1), 213-31.

It is useful to estimate peak floor accelerations consistent with the specified seismic hazard for ensuring the safety of rigid nonstructural components in structural systems. A modal combination rule is formulated here to estimate peak floor accelerations in a multistoried building directly in terms of the dynamic properties of the building and pseudo spectral acceleration ordinates of the base excitation. The formulation is developed under the framework of stationary random vibration theory for a linear, lumpedmass, classically damped, multi-degree-of-freedom system with the help of some approximations. A numerical study shows that the proposed rule performs well with the maximum average absolute error in any combination of building and excitation being less than 20% in case of 5% damping. Two simpler SRSS-type variants of the proposed rule, one considering modal cross-correlation and another ignoring this, are also shown to perform reasonably well, particularly when the building is not flexible to the ground motion.

6 illus, 5 tables, 33 ref

012616   Rao V M;Rao B P;Potukuchi D M (Electronics and Communication Engineering Dep, GITAM College of Engineering, Visakhapatnam-530 045, Email: mraoveera@yahoo.com) : Dielectric parameters as diagnostic tools and Indicatrix of disease - a microwave study. IETE Tech Rev 2008, 25(2), 91-96.

An X-band microwave, (9-10 GHz) technique to determine the dielectric blood parameters as an indicatrix for the severity of disease is reported. Relevance of dielectric parameters as the main indicators in the area of diagnostic tools is discussed. An experimental set-up and the relevant procedural details for the measurement of microwave blood parameters for the typhoid and diabetic disease is presented. Microwave (MW) dielectric parameters viz, dielectric constant ε_r*(ω), wave velocity v (ω)and the impedance z(ω)are measured for collected blood samples (from hospitals) and compared to the clinical values reflecting the disease severity. The dielectric parameters are identified to exhibit similar trends as exhibited by clinical parameters for disease severity. Parametric relations are obtained to address the correlation between dielectric and clinical parameters reflecting the severity. The capability of MW dielectric measurements as the diagnostic tools and severity indicators is demonstrated.

3 illus, 2 tables, 13 ref

012615   Ramji M;Nithila E;Devvrath K;Ramesh K (Solid Mechanics Group, Applied Mechanics Dep, Indian Institute Technology Madras, Chennai-560 036, Email: kramesh@iitm.ac.in) : Assessment of autonomous phase unwrapping of isochromatic phase maps in digital photoelasticity. Sadhana 2008, 33(1), 27-44.

Photoelasticity is the only whole-field experimental technique which can analyse both 2-D and 3-D elasticity problems. In digital photoelasticity one gets two phase maps, one corresponding to principal stress direction (isoclinic) and the other corresponding to principal stress difference (isochromatic). The phase maps for both isoclinics and isochromatics are to be unwrapped differently for obtaining continuous phase values. Autonomous phase unwrapping is one of the challenging issues and this paper focuses on recent advances on isochromatic phase map unwrapping. A comparative study of different autonomous phase unwrapping algorithm is done by solving a bench mark problem and a stress frozen slice with cut-outs. The need for domain delimiting in addition to domain masking is brought out while using autonomous phase unwrapping algorithms.

12 illus, 2 tables, 26 ref

012614   Ramesh M;Kailas S V;Simha K R Y (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: mramesh.mecheng.iisc.ernet.in) : Wave propagation in coated cylinders with reference to fretting fatigue. Sadhana 2008, 33(3), 339-56.

Fretting fatigue is the phenomenon of crack initiation due to dynamic contact loading, a situation which is commonly encountered in mechanical couplings subjected to vibration. The study of fretting fatigue in high frequency regime has gained importance in recent years. However the stress wave effects at high frequency loading is scanty in the literature. The objective of present investigation is to study stress wave propagation in cylinders with reference to high frequency fretting. The case of a coated cylinder is considered since coating is often provided to improve tribological properties of the component. Rule of mixtures is proposed to understand the dispersion phenomenon in coated or layered cylinder knowing the dispersion relation for the cases of homogeneous cylinders made of coating and substrate materials separately. The possibility of stress wave propagation at the interface with a particular phase velocity without dispersion is also discussed. Results are given for two different thicknesses of coating.

6 illus, 9 ref

012613   Ramesh M;Kailas S V;Simha K R Y (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: mramesh@mecheng.iisc.ernet.in) : Micro and macro contact mechanics for interacting asperities. Sadhana 2008, 33(3), 329-38.

Contact of rough surfaces at micro and macro scales is studied in this paper. The asperities at micro scale are characterised by small radius of curvature whereas the waviness is characterised by large radius of curvature. When two rough surfaces come in contact, on the micro scale, of asperities contacts in a very small area leave large gaps between the surfaces; whereas on the macro scale the surfaces conform to each other under the application of load without gaps. Contact at micro scale is modelled by superposition of Hertzian stress fields of individual asperity contacts and the waviness at macro scale is modelled as a mixed boundary problem of rough punch indentation where displacements of uneven profile are prescribed along the region of contact. In both the cases for simplification the roughness is assigned to one surface making the other surface perfectly flat an assumption often made in contact mechanics of rough bodies. The motivation for modelling the asperities at micro scales comes from the preliminary results obtained from photoelastic experiments. Numerical results are presented based on the analytical results available for Hertzian contacts. The motivation for modelling the asperities at macro scales comes from the results available in literature for flat contacts from solving mixed boundary elasticity problems. A condition of full stick is assumed along the contact which is a common assumption made for rough contacts. The numerical results are presented for both the cases of rough contact at micro and macro scales.

6 illus, 9 ref

012612   Ramesh M;Kailas S V;Simha K R Y (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: mramesh@mecheng.iisc.ernet.in) : Axisymmetric fretting analysis in coated cylinder. Sadhana 2008, 33(3), 299-327.

Fretting is essentially a contact fatigue phenomenon, although bulk stresses and material properties contribute to final failure. The near surface state of stress developed under oscillatory contact between machine elements plays a major role in deciding the severity of fretting. It is possible to enhance tribological properties by coating the surface. There is rather scanty literature available on fretting analysis of coated components. Presence of such coatings has a large influence on the near surface state of stress. The effect of coatings on the severity of fretting is the focus of this paper. Results obtained for both hard and soft coatings are compared with the results obtained for the homogeneous case. The component geometry and loading are chosen to be cylindrical to enable 3D elastic axisymmetric fretting analysis. The results are compared with 2D models (strip and half-plane) to examine their utility and validity for understanding axisymmetric fretting. Contact pressure and frictional shear loading cases are solved separately and superposed appropriately depending on the coefficient of friction considered. Results for different values of coefficient of friction and elastic mismatch are illustrated through contour plots of stresses and strains. These results are expected to be helpful for identifying fretting failure zones and fracture mechanisms in coated components. Analytical results presented here could serve as useful benchmarks for calibrating numerical codes and experimental techniques.

18 illus, 19 ref

012611   Ramesh M;Kailas S V;Simha K R Y (Mechanical Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: mramesh@mecheng.iisc.ernet.in) : Near surface stress analysis strategies for axisymmetric fretting. Sadhana 2008, 33(3), 273-97.

Fretting is essentially a surface phenomenon, but bulk stresses and material properties contribute to subsequent failure. This feature of fretting demands a thorough understanding of near surface stresses under the joint action of normal, shear and thermal loading. Axisymmetric fretting is of great concern in piping and coupling design. In this paper, we develop design tools for Near Surface Analysis (NSA) for understanding axisymmetric fretting. Axisymmetric Fretting Analysis (AFA) becomes formidable owing to localised tractions that call for Fourier transform techniques. We develop two different NSA strategies based on two-dimensional plane strain models: 2D strip model (2DS) and half-plane Fla-mant model (2DF). We compare the results of 2DS and 2DF with the exact results for AFA obtained using Love's stress function in conjunction with Fourier transform. There is a good correspondence between stress components obtained from 2D-models.

23 illus, 25 ref

012610   Ramachandran T V (Environmental Assessment Div, Babbha Atomic Research Center, Trombay, Mumbai-400 085) : Environmentaal thoron (<. Indian J envir Prot 2008, 28(8), 733-52.

Studies on natural background radiation is a topic, which evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of ²²²Rn and its progeny, there was a great upsurge of interest in the measurement of ²²²Rn in the environment. Subsequently, considerable data is being generated on the levels of ²²²Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to ²²⁰Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true from the recent studies resulted in observing high ²²⁰Rn levels in living environments and work places in various countries and it is increasingly felt that it may be necessary to have data on ²²⁰Rn levels in environment for obtaining a complete picture of inhalation dose. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products, like radon (²²²Rn), and thoron (²²⁰Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated inhalation of ²²²Rn, ²²⁰Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. Due to this it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for any country so far on a national level. ²²⁰Rn problem will also be a problem in industries which uses thorium nitrate. Including India, lamps using thoriated gas mantles are being still used for indoor and outdoor lighting and hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from ²²⁰Rn gas emanated and build up of the progeny in ambient air may also be quite significant. Current status of ²²⁰Rn levels in the indoor environment and workplaces as well as in other industries where large amount of ²³²Th is being handled are being summarized. Methods of measurement and reported levels are also summarized.

20 tables, 74 ref

012609   Ramachandran B;Shanmugavel S (ECE Dep, SRM University, Kattankulathur, Email: profbram@yahoo.com) : Received signal strength-based cross-layer designs for mobile ad hoc networks. IETE Tech Rev 2008, 25(4), 192-200.

In fourth generation (4G) wireless networks and beyond, it is strongly anticipated that mobile ad hoc network will be used to economically extend their coverage and capacity. The mobile ad hoc networks provide new applications, but also face significant technical challenges. Recently, it has been argued that layered architectures are not suitable for wireless networks. In an effort to improve the performance of mobile ad hoc networks, there has been increased interest in protocols that rely on cross-layer interactions between different layers. Proposes and studied three cross-layer designs among physical, medium access control and routing (network) layers, using Received Signal Strength (RSS) as cross-layer interaction parameter for energy conservation, unidirectional link rejection and reliable route formation in mobile ad hoc networks. These proposed cross-layer designs are implemented using GloMoSim, the Global Mobile Simulator, and the performance of cross-layer protocol frame work is studied.

9 illus, 12 ref

012608   Raja T;Kalaichelvi P;Ananthraman N (NO, Chemical Engineering Dep, NIT Trichy) : CFD simulation and experimental validatation of jet mixer with conical bottom. Process Pl Engng 2007, 25(3), 27-32.

Many experimental studies have been carried out to study the mixing in liquid jet agitated tanks. In this study, numerical simulation is carried out to study the effect of shape of tank on mixing time in a conical based cylindrical vessel. This paper reports the results of the study on the flow generated in such tank. For this purpose, a tank is modeled using FLUENT6.1. The model has the ability of simultaneous solving of continuity, the Reynolds-averaged Navier -Stokes (RANS) equations and employing various types of turbulence models. The results show that there are considerable differences between the various geometries taken. The geometry considered is a Cylindrical tank with a conical bottom. A bottom pump around tank with a single jet arrangement is used. An experiment is also done to validate the results obtained by the numerical study.

11 illus, 10 ref

012607   Praveen Kumar;Saxena A (Civil Engineering Dep, IIT, Rorkee) : Upgradation planning of rural roads in gis environment under PMGSY. Indian Highw 2008, 36(10), 13-21.

In study, the planning model for upgradation of rural roads is developed by keeping PMGSY program as the base of this model. The validation of the developed planning model is done in the Pilana block of the Baghpat district in Uttar Pradesh. The model is validated with the help of Geographic Information System. The software used here is Arc View. For verifying model a database (village and road information System) is also developed. Core Network upgradation is done and final map is prepared showing the number of roads needs strengthening and widening. Final alternate route is also worked out.

5 illus, 1 table, 2 ref

012606   Patnaik A K;Bauer C L;Srivatsan T S (Civil Engineering Dep, The Univ of Akron, Akon, Ohio 44325 3905, USA, Email: tsrivatsan@uakron.edu) : Extrinsic influence of carbon fibre reinforced plastic laminates to strengthen steel structures. Sadhana 2008, 33(3), 261-72.

The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and discussed in this paper were obtained by closely studying the behaviour of steel beams strengthened with carbon FRP material. An attempt is made to succinctly summarise the findings for two different types of strengthening of the steel beams using carbon FRP laminates. The first type of beams focuses on enhancing the strength of steel in flexure while the second focuses on increasing the shear strength of the beams. Three beams were designed so as to cause them to fail in flexure. Of the beams studied, two were strengthened using carbon FRP strips attached to the tension flange. One of the beams was tested to facilitate comparison of their behaviour to the two beams which are strengthened in flexure. Three other beams were designed such that they failed predominantly in shear. Of these three, two were strengthened with carbon FRP strips attached to the webs while the third beam was used as a control beam for the purpose of drawing comparisons. Preliminary results revealed a noticeable increase in the strength for both the flexure strengthened beams and the beams strengthened in shear. The observed increase in shear strength of the beams was 26% while the increase in strength for the beams tested in flexure was 15%. This study convincingly shows that it is possible to strengthen steel beams using carbon FRP laminates in both flexure and in shear.

7 illus, 2 tables, 9 ref

012605   Pal T K (NO, Research Centre Imarat, Hyderabad-500 069) : Series resistance of silicon millimeter wave (Ka-band) IMPATT diodes. Def Sci J 2009, 59(2), 189-93.

Describe a computer-based method to calculate the series resistance R of a millimeter wave Ka-band packaged IMPATT diode from small signal conductance-susceptance characteristics. The series resistance R_s has been calculated at the threshold condition when the small signal conductance of the packaged diode just becomes negative and the device susceptance becomes positive. Again, the value of series resistance R has been determined from the measurement of threshold current and threshold frequency with the silicon Ka-band IMPATT diode embedded in a resonant cap cavity which agrees well with the values obtained by the computer method.

8 illus, 3 tables, 11 ref

012604   Pal S;Mukhopadhyay A K;Bhattacharya P P (Electronics and Communication Engineering Dep, Dr. B.C. Roy Engineering College, Durgapur-713 206, Email: mailsarit@yahoo.co.in) : Defending mechanisms against sybil attack in next generation mobile ad hoc networks. IETE Tech Rev 2008, 25(4), 209-15.

Presents techniques adopted to defend against Sybil Attack in Mobile Ad Hoc Networks. Sybil attack and the existing defense mechanisms against this type of attack have been reviewed and their loopholes are indicated. Multifactor Authentication Scheme has been discussed pointing out its superiority over traditional Cryptography-based Authentication Schemes. Afterwards, Passive Ad Hoc Sybil Identity Detection techniques differentiating a Sybil attacker from a group of legitimate nodes moving together is also discussed. Merits and demerits of these methods are mentioned and also the scopes for future research to improve these detection schemes have been indicated.

11 ref

012603   Pagalthivarthi K;Gupta P K (NO, GIW Industries Inc, Grovetown, GA 30813, USA, Email: pankajgupta@gmail.com) : Particle tracking in rotating channel flow. Indian J Engng Mater Sci 2008, 15(5), 365-76.

Study deals with the numerical simulation of dilute solid-fluid flow in a two-dimensional straight rotating channel using Lagrangian particle tracking method. The developing carrier-phase flow, assumed to be steady in the mean, is ?computed using Galerkin finite element method. A rotation-modified k-∈ model is used to account for the effect of turbulence on the mean flow. One-way coupling is assumed, i.e., the carrier-phase flow affects the particle motion, but not vice-versa. Model coefficients of restitution in the normal and tangential directions are used. The particle equations of motion include drag, pressure, centrifugal, Coriolis, virtual mass, and friction (in case the particle slides along the wall) forces. Mesh refinement and comparison with published numerical results are used to validate the code. Effects of such operating parameters as rotation rate, particle size, specific gravity and coefficients of restitution are discussed.

10 illus, 1 table, 26 ref

012602   Nuray Aydinoglu M (Earthquake Engineering Dep, Kandilli Observatory and Earthquake Research Institute (KOERI), Bogazi, Istanbul, Turkey) : Response spectrum-based nonlinear assessment tool for practice: incremental response spectrum analysis (IRSA). ISET J Earthquake Technol 2007, 44(1), 169-92.

Response Spectrum Analysis (RSA) procedure has become a standard analysis tool in traditional strength-based design of buildings and bridges under reduced seismic loads. RSA has been recently extended to estimate nonlinear seismic demands. The Incremental Response Spectrum Analysis (IRSA) procedure is based on a straightforward implementation of RSA at each piecewise linear incremental step in between the formation of consecutive plastic hinges. The practical version of IRSA works directly with smoothed elastic response spectrum and makes use of the well-known "equal displacement rule" to scale modal displacement increments at each piecewise linear step. IRSA can be characterized as an adaptive multi-mode pushover procedure, in which modal pushover analyses are simultaneously performed for each mode at each incremental step under appropriately scaled modal displacements followed by an application of a modal combination rule. Examples are given to demonstrate the practical implementation of IRSA.

10 illus, 2 tables, 34 ref

012601   Nevase S S;Dubey A K;Shinde K J;Kadu B D (NO, College of Engineering, Solapur-413 304) : Performance and evaluation of 35 HP tractor on biodiesel. Green Fmg 2008, 2(2), 117-20.

Research work was undertaken to study performance and evaluation of 35 hp tractor on biodiesel from jatropha oil. The biodiesel was prepared by the process of transesterification of the unfiltered jatropha oil, in presence of three per cent of KOH catalyst and ethanol (30 per cent volume basis). The prepared JEE was tested in 35 hp tractor for its operation and evaluation. The parameters studied were BSFC, BSEC, and engine efficiency. BSFC was found increased with increase in per cent of JEE in fuel blend. It was found that BSEC increases with increase in brake power. It was also observed that engine efficiency increases with increasing the fuel blend but decreased slightly at the blend B-50. Exhaust emission study was done for the parameters like exhaust gas temperature, smoke opacity, emission of CO, NO, NO₂ and Nox. During study it was observed that increase in exhaust temperature from B0 to B50 was 4.54 per cnet. The smoke capacity decrease from B0 to B50 was 11.86 per cent. Carbon monoxide, reduced with increase in JEE percentage in fuel. Oxides of nitrogen was found to be increased by 7.84 per cent as the JEE per cent increases. Maximum sound pressure level were studied and it was found that the sound level decreased from B0 to B 50 by 2.55 per cent.

10 illus, 2 tables, 7 ref

012600   Nemamcha A;Moumeni H;Rehspringer J L (Laboratorie d'Analyse Industrielle et Genie des Materiaux, Dep de Chi, Universite 08 Mai 1945 de Guelma, B.P. 401, Guelma 24000, Algerie, Email: arnemamcha_dz@yahoo.fr) : Effects of sonication time on the Pd(II) ions reduction and the Pd nanoparticles formation. Int J mathl Sci 2008, 3(1), 53-9.

Highly dispersed palladium nanoparticles have been obtained by ultrasonic irradiation of Pd(NO₃)₂ solution in presence of ethylene glycol (EG) and polyvinylpyrrolidone (PVP) at different sonication time. The sonochemical reduction process of palladium ions (Pd(II)) to palladium atoms (Pd(0)) can be explained by the acoustic cavitation: formation, growth and collapse of bubbles. In the sonochemical process, there are three different stages where the reduction of Pd(II) ions in the aqueous solution can occur. The water pyrolyze into H and OH, the radical formation from EG, and the reduction of Pd(II) ions. The UV-Visible results analyses show that the sonochemical reduction rate of Pd(II) into Pd(0), which control the palladium nanoparticles formation, depends on the sonication time. The reduction process can be divided in three periods. During the first sonication period, the Pd(II) ions are rapidly reduced into Pd(0) atoms and the formation of primary particles can occurs. The increase of sonication time, induces the progressive decrease of the Pd(II) reduction rate which enhance the growth of primary particles. The third period corresponds to the high sonication time, the reduction rate of Pd(II) ions is very weak and the growth of the stable PVP-Pd nanoparticles is negligible. TEM and EDX investigations prove that the obtained suspension is constituted by the single palladium particles. These Pd nanoparticles are highly dispersed, with a rounded shape and an average diameter of about 4 nm.

5 illus, 15 ref

012599   Naidu V P S (NO, National Aerospace Laboratories, Bangalore-17) : Fusion of radar and IRST sensor measurements for 3D target tracking using extended Kalman filter. Def Sci J 2009, 59(2), 175-82.

Tracking algorithms for IRST and radar are implemented and their performance is checked with simulated data. Detailed mathematical expressions given could be useful for implementation. Performance evaluation metrics have been presented to check the tracking algorithm performance. Two fusion schemes have been presented and their performances evaluated with simulated data. It is concluded that both fusion schemes performed alike with the second fusion scheme giving slightly better results. From the results, it is also concluded that fusion of IRST and radar would improve the tracking performance and reduce the positional uncertainty compared to individual trackers.

11 illus, 4 tables, 7 ref

012598   Muscolino G;Palmeri A (Civil Engineering Dep, University of Messina, Vill. S. Agata, 98166, Messina, Italy) : Earthquake response spectrum method for linear light secondary substructures. ISET J Earthquake Technol 2007, 44(1), 193-211.

Earthquake response spectrum is the most popular tool in the seismic analysis and design of structures. In the case of combined primary-secondary (P-S) systems, the response of the supporting P substructure is generally evaluated without considering the S substructure, which in turn is only required to bear displacements and/or forces imposed by the P substructure ("cascade" approach). In doing so, however, dynamic interaction between the P and S components is neglected, and the seismic-induced response of the S substructure may be heavily underestimated or overestimated. A novel CQC (Complete Quadratic Combination) rule is proposed for the seismic response of linear light S substructures attached to linear P substructures. The proposed technique overcomes the drawbacks of the cascade approach by including the effects of dynamic interaction and different damping in the substructures directly in the cross-correlation coefficients. The computational effort is reduced by using the eigenproperties of the decoupled substructures and only one earthquake response spectrum for a reference value of the damping ratio.

10 illus, 2 tables, 33 ref

012597   Murali Krishna M V S;Naga Sarada S;Sudha Rani G;Radha Kalyani K;Murthy P V K (Mechanical Engineering Dep, Chaitanya Bharathi Institute of Technology, Gandipet, Hyderabad-500 075) : Comparative study of exhaust emissions of a low heat rejection engine with two different levels of insulation with alrternate fuels. Indian J envir Prot 2008, 28(8), 690-4.

Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nature. Alcohols can not be used directly in compression ignition engines as they have low cetane number. Vegetable oils have drawbacks of low volatility and high viscosity. The drawbacks associated with these fuels call for low heat rejection engines. The major pollutants emitted from diesel engine are smoke and oxides of nitrogen. Inhaling of these pollutants affect the human health apart from causing environment disorders. Investigations have been carried out on a low heat rejection (LHR) diesel engine with air gap insulated piston with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with varied air gap thickness with carbureted methanol and crude jatropha oil at different injection pressures. The LHR diesel engine with carbureted methanol and crude jatropha oil decreased the pollution levels in comparison with vegetable oil operation on conventional engine.

1 illus, 2 tables, 9 ref