007957   Sanni S H;Khadiranaikar R B (Civil Engg. Dep, Basaveshwar Engineering College, Bagalkot, Email: shsanni@gmail.com) : Performance of geopolymer concrete under severe environmental conditions. Int J civ struct Engng 2012, 3(2), 396-407.

This paper presents the experimental investigation done on performance of geopolymer concrete subjected to severe environmental conditions. The grades choosen for the investigation were M-30, M-40, M-50 and M-60, the mixes were designed for molarity of 8M and 12M. The alkaline solution used for present study is the combination of sodium silicate and sodium hydroxide solution with the ratio of 2.50 and 3.50. The test specimens were 150x150x150 mm cubes, 100x200 mm cylinders heat-cured at 60°C in an oven. The geopolymer concretes (GPCs) have inorganic polymer of alumino-silicates as the binder whereas the conventional concretes have Portland cement (P-C) generated C-S-H gel (beside freelime). It is well known that mechanisms of attack by sulphuric acid and magnesium sulphates are different. Conventional concretes are generally not resistant to prolonged exposure to very high concentrations of these solutions because decalcification of C-S-H will occur. As a result of this, OPC concrete surface becomes soft and could be removed, thus, exposing the interior concrete layers to deterioration. At the same time as the magnesium sulphate attack, causes decalcification of C-S-H to form magnesium silicate hydrate (M-S-H). It also destroys the binding capacity of C-S-H and leads to a loss of adhesion and strength in concrete. Durability of specimens were assessed by immersing GPC specimens in 10% sulphuric acid and 10% magnesium sulphate solutions separately, periodically monitoring surface deterioration and depth of dealkalization, changes in weight and strength over a period of 15, 30 and 45 days. The test results indicate that the heat-cured fly ash-based geopolymer concrete has an excellent resistance to acid and sulphate attack when compared to conventional concrete. Thus we can say that the production of geopolymers have a relative higher strength, excellent volume stability and better durability.

13 illus, 6 tables, 19 ref

007956   Sahu R R;Gupta P (Civil Engineering Dep, IIT, Roorkee, Email: RamRanjanSahu@tatatechnologies.com) : Comparative large deformations studies on circular tubes. Int J civ struct Engng 2012, 3(2), 367-79.

This paper describes the large deformation phenomenon and compares the plastic energy absorption of tubes, for the different phenomenon Experiments were conducted on circular aluminum tubes having typical external diameter of 25.5 mm and thickness 2 nm Generally the tube lenghts were 100mm. Also 50mm lengths were chosen to see the length effect on the deformation Phenomenon Numerical analysis was performed to simulate the different. A good agreement was observed between experimental data and numerical The force-stroke curves of difterent deformation modes are discussed in detail Various characteristics, associated with large deformation are explored and discussed. Based, Based on these experimental studies, best energy absorption phenomenon is found.

9 illus, 1 table, 15 ref

007955   Ramakanth S (NO, Visakha Institute of Engineering and Technology, Visakhapatnam, Andhra Pradesh, Email: ramakanth000@gmail.com) : Cheaper electrodes having higher efficiency using salt water and salt vinegar electrolytes. Asian sci 2012, 7(2), 173-8.

This paper gives how salt water and salt vinegar is used as renewable energy resources. Working of salt water and salt vinegar electrolytes and the combination of these two electrolytes were analyzed in this work. The comparison of other electrodes used as electrolytes and choosing the best pair of electrodes to produce maximum electricity were verified.

^iia2 illus, 3 tables, 11 ref

007954   Radhika K S;Baskar K (NO, National Institute of Technology, Trichy, Email: radhika.sridhar2210@gmail.com) : Bond stress characteristics on circular concrete filled steel tubular columns using mineral admixture metakaoline. Int J civ struct Engng 2012, 3(1), 1-8.

Concrete filled steel tubular columns are becoming widely used in engineering. This paper studies the bond stress characteristics in concrete filled steel tubular columns using mineral admixture (metakaoline). Also this paper presents the effects of change in length of the tube, diameter of the tube, strength of the infill concrete and percentage variation of metakaoline in concrete. CFT applications in buildings and the importance of bond stress are studied. This paper presents the bond carrying capacity of twelve conventional concrete and thirty six metakaoline in concrete filled steel tubular columns. The effect of metakaoline in concrete was also investigated. The bond carrying capacity is interrelated with slip between steel and concrete interface. From the experimental study it was found that the bond stress decreases with increasing in percentage of metakaoline. An experimental study is described and evaluated.

6 illus, 3 tables, 14 ref

007953   Qasim S;Harahap I (NO, Teknologi PETRONAS Univ, Bandar Seri Iskandar, 31750 Tronoh, Perak, Darul Ridwan, Malaysia, Email: nuzhaterum@gmail.com) : Probabilistic analysis of Malaysian bored piles. Int J civ struct Engng 2012, 3(2), 380-95.

Initiating to introduce Load Resistance Factor Design in Malaysian Geotechnical industry is also one of the leading motives as LRFD is reliability based method, can work out the probability of failures of the structure and estimate the reliability through statistical knowledge. To overcome the coming risks and the uncertainties in a best possible manner, demands of incorporating LRFD in practice is a dire need of this century. In terms of providing solution of how to strengthen the sub-structures, reliability based LRFD method is proposed and emphasized by calculating resistance factors of bored pile through First Order Second Moment also known as First Order Reliability Method (FORM( and Mean Value First Order Second Moment (MVFOSM) rather the application of fitting strategy. Statistical methods FOSM, AFOSM used to compute the beta values and resistance factors. Comparison of both methods has also been performed. As the most dominant is bore pile so in this document this structure is used for the reliability analysis. Cases of four Kuala Lumpur sites have been taken as a sample to get statistical data. Although the resistance factors developed is not so refined but at least conservative values of resistance factors are in hand to carry out LRFD.

9 illus, 13 tables, 31 ref

007952   Poddar G C;Jain S C;Tewari U;Mehla N S;Kapur P (NO, CSIR-Central Scientific Instrument Organisation, Sector 30-C, Chandigarh-160 030) : Photonics and fiber bragg grating sensor. Bhartiya Vaigyanik Evam Audyogik Anusandhan Patrika 2013, 21(1), 31-7.

In the recent years, photonics has emerged as a large area consisting of different waves of electro-magnetic radiations (Electro-magnetic Spectrum) which are being applied in the communications, Sensors, Laser, Quantum Optics, Opto-mechanics, Electro-optics and Opto & Quantum Electronics etc. In photonics, fiber optic sensor is an important new subject which is being proved very useful in the applications of Health Monitoring of Civil, Mechanical and Aeronautical structures. FBG sensor is one of them which is widely discussed in this research paper. In photonics, Bragg grating is defined as the periodic modulation of refractive index inscribed permanently in the core of fiber from which a particular wavelength (λ_B) is reflected with high intensity on launching Ultraviolet light. This wavelength (λ_B) depends upon the grating pitch. FBG sensor performs as a Band Pass Filter that reflects the wavelength with high intensity after filtering it from the grating. This paper focuses on Fiber Bragg Grating Writing Techniques, its experiments and applications.

5 illus, 1 table, 10 ref

007951   Poddar G C;Jain S C;Mehla N S;Kapur P (NO, CSIR-Central Scientific Instrument Organisation, Sector 30-C, Chandigarh-160 030) : Development of fiber optic point-temperature sensor. Bhartiya Vaigyanik Evam Audyogik Anusandhan Patrika 2013, 21(1), 22-6.

Fiber optic sensor for monitoring point-temperature of in-situ reactions in remote, based on the principle of guiding light by means of total internal reflection (TIR) occurring in a right-angled prism, mounted on a glass capillary tube comprises isopropyle alcohol in it and rises due to increase in temperature and touches the prism surface thereby preventing the occurrence of TIR thus reducing the level of output optical signal detected. The fiber optic point temperature sensor is a suitable device for controlling temperature of chemicals, medicines and oils widely used in defence and engineering applications. This device is very useful in petrochemcal industry, process control industry, moisture controlling in food storage, electrical and oil and gas exploration and mining industry.

4 illus, 8 ref

007950   Patil M;Pandey A D (Earthquake Engineering Dep, Indian Institute of Technology, Roorkee, Uttarakhand, Email: maan4patil@gmail.com) : Influence of Semirigid joints on fatigue life of steel truss railway bridge. Int J civ struct Engng 2012, 3(1), 44-56.

Joints of Riveted Steel Truss Railway Bridge consist of gusset plates which lose their rigidity due to repeated passages of train loads; therefore the loss of rotational rigidity is to be taken into account in analysis of Bridge. This joint flexibility tends to alter the vibration characteristics of the Bridge system and each component of the bridge responds dynamically to the rapidly varying loads and thus the time history obtained is a function of load variation and dynamics of the structure, which consequently affects fatigue life of the bridge components. In past, effect of Semirigid joints has been studied in case of building frames. So here the knowledge of semirigid joints on building frame has been extended to Steel Truss Railway Bridge. This present article tries to study the influence of joint flexibility on the fatigue life of 76.2 m Truss bridge due to moving load at different speeds. The joint rotational stiffness are reduced by 5%, 10%, 25% and 50%. The result of preliminary studies conducted on Steel Truss Bridge is presented. It is prime facia that upto 50% reduction in rotational Stiffness of the joints does not affect the stability of the bridge. However more detailed studies are required to confirm the findings.

20 illus, 5 tables, 28 ref

007949   Pandey K M;Singh A P (Mechanical Engineering Dep, National Institute of Technology, Silchar, Assam, Email: kmpandey2001@yahoo.com) : Computational analysis of supersonic combustion with co-axial jet flow. J Envir Res Dev 2011, 6(2), 344-55.

In this Paper study, supersonic combustion of hydrogen using S-A and K-ω Turbulence Model has been presented. The combustor has a single fuel injection parallel to the main flow from the base. Mixing, penetration and combustion characteristics of injected fuel and air in combustor are presented here. Increase in jet to free stream momentum flux ratio will result in the increase of jet penetration to free stream. The ignition delay makes the hydrogen jet mix with the airflow, producing a homogeneous reacting mixture, which does not ignite because the jet temperature is relatively low. Mixing of the cold jet with the hot flow results in an increase in hydrogen-air temperature up to 2420K in S-A model while 2500k in K-ω model, and it is also clear that K-ω model gives higher mach 2.24 than S-A model 2.22 because of the disturbance waves propagating from the flame front are reflected from the flow boundary and, interacting with each other, from a wave structure with compression and expansion zones separated by oblique shock.

13 illus, 1 table, 25 ref

007948   Pal Y;Baskar J;Murugesan S (NO, Hindustan Univ, Chennai-603 103, Email: yashsoni06@gmail.com) : Testing of paraffin-based hybrid rocket fuel using gaseous oxygen oxidiser. Def Sci J 2012, 62(5), 277-83.

Series of paraffin-based hybrid rocket fuel has been studied experimentally in a laboratory-scale motor. To enhance the regression rate of paraffin solid fuel, three types of grain configurations: Cylindrical, star, and helical grain configurations of paraffin wax have been developed and tested with gaseous oxygen. The helical fuel grain presented best performance among all the test ports. About 40.2 per cent and 20.6 per cent regression rates are increased by burning paraffin fuel with helical and star grain configuration respectively, as compared to cylindrical grain configuration at G_ox = 0.0191 g/mm²s. The regression rates were significantly influenced by the oxygen injection pressure varied between 344.7 kPa and 620.5 kPa. Furthermore, the experimentally obtained exponents of oxidizer mass flux for all three grain configurations have been found to be significantly different from those of the classical hybrid system. Finally, thrust-time traces for all three grain configurations were also studied. The result shown no significant increase or decrease in the amplitude of the thrust oscillations.

14 illus, 3 tables, 9 ref

007947   Naveen G M;Suresh G S (Civil Engineering Dep, Government Engineering college, Chamarajanagara, Email: naveen.gowda@gmail.com) : Experimental study on light weight ferrocement beam under monotonic and repeated flexural loading. Int J civ struct Engng 2012, 3(2), 294-301.

Light weight ferrocement is a composite material consisting of cement-sand mortar (matrix) along with light weight fine aggregate (In this work foamed blast furnace slag is employed as light weight fine aggregate ) as a replacement of sand in some quantity reinforced with layers of small diameter wire meshes The present work is concentrated on two major aspects, Effect of blast furnace slag on first crack and ultimate strength and Behavior of light weight ferrocement element under monotonic & repeated flexural loading. The first part of the present study has been focused on the effect of blast furnace slag (BFS) on ultimate strength with replacement of slag by 0%, 10%, 20% and 30% and second part of the work focusing the behavior of Light weight ferrocement beam under monotonic load and repeated load with increased load. The results obtained from this work is expected to be useful in determining the strength and ductility of light weight ferrocement beam subjected to similar types of forces and thus will help toward designing ferrocement elements to withstand monotonic and repeated flexural loading.

8 illus, 5 tables, 5 ref

007946   Nandagopan O R;Ranjith Kumar S;Rajesh M R; Manoharan K;Nandakumar C G (Naval Physical & Oceanographic Laboratory, Kochi Cochin Science & Technology Univ, Kochi, Email: ornandaguopan@yahoo.co.in) : Nonlinear behaviour of perforated plate with lining. Def Sci J 2012, 62(4), 248-51.

Perforated plate with lining has a construction of plate with perforation and a lining plate welded together to form a single plate. This type of plate is used as an acoustic sonar dome. Perforated plate with lining (PPL) is prone to stress concentration and subsequently such structural system falls into the large strain category. Experimental investigation on PPL is carried out in the present study to determine the static deflection of the plate. Numerical method is also followed for geometric nonlinear analysis using finite element method as an iterative interactive procedure. The deflection obtained from the numerical method is 8 per cent less than that obtained from experimental method. From numerical analysis, von Mises stress and maximum principal stress is also estimated to understand about the failure mode characteristics of PPL.

5 illus, 3 tables, 11 ref

007945   Nadeem M;Pofale A D (Civil Engineering Dep, Visvesvaraya National Institute of Technology, Nagpur, Email: nadeem1972@rediffmail.com) : Experimental investigation of using slag as an alternative to normal aggregates (coarse and fine) in concrete. Int J civ struct Engng 2012, 3(1), 117-27.

Presents results of experimental investigations carried out to evaluate effects of replacing aggregate (coarse and fine) with that of slag on various concrete properties. The basic objective of this study was to identify alternative source of good quality aggregates which is depleting very fast due to the fast pace of construction activities in India. Use of slag - a waste industrial byproduct of iron and steel production provides great opportunity to utilize it as an alternative to normally available aggregates (coarse and fine). In this study, concrete of M20, M30 and M40 grades were considered for a W/C ratio of 0.55, 0.45 and 0.40 respectively for the replacements of 0, 30, 50, 70 and 100% of aggregates (Coarse and Fine) by slag. Whole study was done in two phases, i.e. replacement of normal crushed coarse aggregate with crystallized slag and replacement of natural fine aggregate with granular slag. The investigation revealed improvement in compressive strength, split tensile and flexure strength over control mixes by 4 to 8%. The replacement of 100% slag aggregate (coarse) increased concrete density by about 5 to 7% compared to control mix. Based on the overall observations, it could be recommended that slag could be effectively utilized as coarse and fine aggregates in all the concrete applications.

12 illus, 4 tables, 9 ref

007944   Mukherjee B;Vishwakarma D K (NO, PDPM-Indian Institute of Information Technology Design & Manufacturin, Jabalpur, Email: biswajeet.26@gmail.com) : Application of finite difference time domain to calculate the transmission coefficient of an electromagnetic wave impinging perpendicularly on a dielectric interface with modified MUR-I ABC. Def Sci J 2012, 62(4), 228-35.

MATLAB codes were implemented in this study for a one dimension wave formulation using the computational technique of finite difference time domain (FDTD) method. The codes have then been verified under two cases, one a simple, one dimensional wave impinging perpendicularly on a dielectric layer from air interface and second is a one dimensional wave impinging momentarily on a small dielectric slab. The transmission coefficients under both the cases have also been verified. For the former case, there is a constant transmission coefficient irrespective of the frequency of the electromagnetic wave impinging on it and for the latter; there is a sinusoidal type variation due to multiple reflections along the wall of the dielectric slab. In the course of this implementation of the codes a novel technique to implement the absorbing boundary condition (ABC) on the dielectric interface has also been devised based on the Mur-I ABC which has been verified for a dielectric of dielectric constant 4ε_o. The implementation of the codes presents a recapitulation of the evolution of FDTD from Yee's Algorithm to the latest modifications in the ABC.

16 illus, 16 ref

007943   Mohamadien H A (NO, Faculty of Engineering, Suez Canal Univ, Ismailia, Egypt, Email: h_mohamadien@yahoo.com) : Effect of marble powder and silica fume as partial replacement for cement on mortar. Int J civ struct Engng 2012, 3(2), 418-28.

Marble powder material (MP) is a very fine powder, obtained as a by-product of marble during the sawing and the shaping, and not recycling it due to environmental problems in the world. The possibility of using it and silica fume (S.F) separately as partial replacement of cement on mortar were studied and evaluated based upon the percentage of the partial cement replacement with both marble powder and silica fume separately. Four types of mortar mixture with same workability, cement to sand ratio of 1:3 and water to cementitious materials ratio of 0.4 were prepared marble powder and silica fume used in mixes separately, once as a partial replacement of cement content and another as an addition to the mix proportion. Replacement and addition ratio of both marble powder and silica fume with cement content separately at 0%, 5%, 10%, 15%, 20%, 30% and 50% by weight were investigated. The mechanical properties of mortar were measured in terms of compressive strength at 7 and 28 days and it was observed that the strength developments at 7, and 28 days and the highest development rate of compressive strength was observed at 15% replacement ratio for each the marble powder and silica fume separately. Results showed that the compressive strength increased by 31.4%, 48.3% at 7, and 28 days respectively at 15% replacement ratio of silica fume with cement content and in case of replacement marble powder with cement content the compressive strength increased by 22.7%, 27.8% at 7, and 28 days at 15% replacement ratio of marble powder with cement content respectively.

5 illus, 12 tables, 15 ref

007942   Mishra S P;Parbat D K (Civil Engineering Dep, Bhilai Institute of Technology, Durg, Chhattisgarh, Email: spmbits@gmail.com) : Sensitivity analysis of multi parameter mathematical model in reinforced concrete construction. Int J civ struct Engng 2012, 3(1), 197-204.

Objective of the paper is the sensitivity analysis of manual formwork activity of Reinforced concrete structures. Sensitivity analysis is used to analyze how sensitive a system response with respect to change in key input parameters of construction phenomenon.

2 illus, 5 tables, 14 ref

007941   Mishra R K;Parida M;Rangnekar S (CTRANS, Indian Institute of Technology, Roorkee, Email: rajeevmishraiitr@gmail.com ) : Urban transport system: an environmentally sustainable approach. J Envir Res Dev 2012, 6(3), 500-6.

Rapid motorization and urbanization can bring many environmental issues that can endanger the sustainability of cities. Like many big urban cities, the city of Delhi in India is also suffering from various environmental problems. Road traffic is considered as a primary source of air and noise pollution. Due to the high level of uncertainty regarding the future effect of existing condition, it is very challenging for policy makers to develop policies which result in an environmentally sustainable transport system. In such a complex situation, it is very essential to give sufficient attention in planning environmental friendly transport systems, modes of public/private motorized transport, non-motorized transport and along with road user safety. The paper is an attempt to covers various environment related modules of transport system like traffic air and noise pollution due to traffic congestion. It deals with the existing trends of noise pollution at sensitive locations in Delhi city, their impact on human health and their conceptualization in terms of sustainability and recommended various steps for the planning of transport systems to make it environmentally sustainable. The paper has scrutinized the extent of problem and recommends counteractive measures. The paper will suggest ideas and challenges of creating environmentally sustainable transport systems in Indian metropolitan cities like Delhi along with detailed discussion on the existing environmental problems and poor motorized system of transport.

5 illus, 12 ref

007940   Mevada S V;Jangid R S (Civil Engineering Dep, Indian Institute of Technology Bombay, Powai, Mumbai - 400 076, Email: snehalvm@iitb..ac.in) : Seismic Response of Asymmetric Structures with Variable Dampers. Int J civ struct Engng 2012, 3(1), 31-43.

Seismic response of linearly elastic single-storey, one-way asymmetric structure installed with semi-active variable dampers is investigated under earthquake ground motions. The response is evaluated by considering the two-step viscous damping algorithm by numerically solving the governing equations of motion using state space method. The effects of lateral time period and uncoupled torsional to lateral frequency ratio are investigated on lateral, torsional and edge displacements as well as accelerations. The parametric study indicated that the semi-active variable dampers are quite effective in reducing various responses. It is further observed that the effects of torsional coupling and effectiveness of control system strongly depends on lateral time period and uncoupled torsional to lateral frequency ratio.

9 illus, 1 table, 10 ref

007939   Mathur Y B;Poonia M P;Jethoo A S (NO, Government Polytechnic College, Bikaner, Rajasthan, Email: asjethoo@gmail.com) : Effect of vegetable oils and biodiesel on engine performance, combustion, and exhaust emission characteristics : A review. J Envir Res Dev 2011, 6(2), 372-8.

Energy is the most important component of human life. There has been phenomenal increase in the consumption of energy in the world in the last few decades. It is because of the rapid increase in world's population and movement of the population from agricultural pursuit to industrialization. Petroleum fuels like diesel and gasoline are the primary sources of energy for sustainable development of any country in the world. With the increase in the energy demands the use of the petroleum products increase tremendously in last few years. Due to limited resources of fossil fuels and the environmental concern, there has been improved focus on vegetable oils and biodiesel fuel as an alternative source of energy. Vegetable oils and biodiesel have the potential to reduce the level of pollution and global warming. Due to scarcity of edible vegetable oils for biodiesel production, non-edible oils seeds such as karanja, jatropha, mahua, sal, neem, rubber, thumba (Citrullus colocynthis), jojoba, caster, cotton seeds etc, are being tapped for biodiesel production. The major problem associated with use of straight vegetable oil includes high fuel viscosity than that of diesel. Thus, although short term tests using neat vegetable oils showed promising results but problems appear like injector coking and piston oil ring sticking after the engine is operated for longer periods. To solve these problems associated with high viscosity, neat vegetable oils are blended in small ratio with diesel or transesterifies to convert it into less viscous biodiesel. In recent time use of vegetable oils and biodiesel obtained from different seeds have been increasingly fuelled in diesel engines to study its effect on engine combustion, performance and emission characteristics but these studies have been rarely reviewed to understand and popularise biodiesel engines. In the present work, the research papers about vegetable oils and biodiesel engine performances, combustion and emission behavior, were cited preferentially since 2001 year and experiences of researchers on variety of seed oils suitability for engine operation and its environmental impacts have been understood and compiled in detail.

^iia30 ref

007938   Mathur R P;Singh R K;Ray S;Ghosal P; Chandrasekaran V (NO, Defence Metallurgical Research Laboratory, Hyderabad-500 058, Email: mathur@dmrl.drdo.in) : Effect of trivalent additions and processing on structural and magnetic transitions in Ni-Mn-Ga ferromagnetic shape memory alloys. Def Sci J 2012, 62(4), 252-60.

Ferromagnetic shape memory Ni₅₀Mn₃₀Ga₁₅Al_5-xB_x (x = 0, 1, and 4) alloys were prepared by vacuum arc melting and subsequent heat-treatment as well as by melt spinning to investigate the effect of trivalent element additions in ternary Ni-Mn-Ga alloys. The heat-treated alloys containing Al were reported to possess a modulated martensite structure, however alloy containing both Al and B showed a loss of modulated structure in martensite formed. The rapidly solidified alloys on the other hand showed the formation of a similar modulated structure without composition change in alloys containing Al and the alloys containing Al and B. In addition, the former showed a presence of an amorphous phase with latter showing crystalline boron rich phases. The magnetisation of the B containing alloys in both the processing technique was however very low, showing lower magnetic exchange interaction in such alloys.

7 illus, 5 tables, 19 ref

007937   Manish Meena;Kuntal M S (NO, JNIT, Jaipur, Email: manishbmit@gmail.com) : Performance analysis of BER with FHSS system. Int J latest Technol Engng Mgmt appl Sci 2013, 2(5), 29-35.

Brief theoretical foundation has worked and explain the expands upon QAM and FSK modulation in the application of Frequency Hopped spread spectrum systems FHSS. Here by the help of this paper, we mainly concentrate on the Bit Error Estimation in Frequency Hop Spread Spectrum System by the use of Quadrature Amplitude modulation and Frequency shift keying which are mainly used in the area of defense applications. The performance of transmission modes are evaluated by calculating the probability of Bit Error Rate (BER) versus the Signal Noise Ratio (SNR) under the frequently used three wireless channel models AWGN, Rayleigh and Rician [2]. We consider the data rate and data modulation to analyze the performance that is BER vs. SNR and we also consider multipath received signals. The transmission performance had shown by simulation results, modes under different channel models and the number of antennas. We observed that some transmission modes are not efficient in IEEE 802.11b based on simulation results,. This paper provides a systematic approach for evaluating the performance of FHSS operating with coherent M-ary FSK demodulation. The investigations into the frequency hop spread spectrum systems employing different modulation schemes to decrease the BER. There has been much more work done on computing BER of FHSS systems with error control coding by using industry standard convolution coding.

6 illus, 16 ref

007936   Lonkar C M;Kharat D K;Kumar H H;Prasad S; Balasubramanian K;Prasad N S (NO, Armament Research and Development Establishment, Pune-411 021, Email: cmlonkar@hotmail.com) : Pb(Ni_1/3Sb_2/3)O₃-PbZrTiO₃ ceramic sensors for underwater transducer application. Def Sci J 2012, 62(4), 269-73.

Cymbal is a class-V flextensional transducer that consists of thickness poled ceramic disc sandwiched between the two metal end caps which acts as a mechanical transformer. Cymbal transducers were fabricated using piezoceramic discs of compositions Pb_0.988 (Zr_0.52Ti_0.48) _0.976Nb_0.0240₃ (PZT type 5A) and Pb_0.98La_0.02(NiSb)_0.05[(Zr_0.52Ti_0.48) _0.995]_0.95O₃ (PNS-PZT). Piezoelectric and hydrostatic constants for PNS-PZT composition were on higher side. End caps were made up of brass sheet having thickness 0.5 mm. Underwater testing of the polyurethane moulded cymbal hydrophones were carried out in acoustic tank and compared. The resonance frequency for both the hydrophones was 10.1 kHz. PNS-PZT hydrophone shows higher sensitivity (-183.2 dB re IV/μPa) compared to PZT type 5A (-191.2 dB re 1V/μPa) at resonance frequencμ. Directivity pattern observed for PNS-PZT is omni-directional near resonance frequency.

4 illus, 2 tables, 14 ref

007935   Lohani T K;Jena S;Dash K P;Padhy M (Civil Engineering Dep, Orissa Engineering College, Bhubaneswar, Email: tkl_66@yahoo.com) : Experimental approach on Geopolymeric recycled concrete using partial replacement of industrial byproduct. Int J civ struct Engng 2012, 3(1), 141-9.

Geopolymer concrete is an advance technology in concrete technology by partial replacement of bonding material (cement) with fly ash after geopolymerization. The geopolymerization chemistry has been conducted by heating the mixture of a specified proportion of fly ash (carbon content <5%), sodium hydroxide (NaOH) and water (H₂O) to a temperature of 60°C to 80°C. Fly ash sample collected from National Aluminum Company (NALCO) of Angul, Odisha having 0.5% carbon content, has been polymerized as per Indian Standard to the referred degree of precision and different samples of different percentage of replacement has been prepared to produce geopolymer concrete. In the investigation, an attempt has been made in preparing concrete of M₂₀ and M25 grade. This clearly reflects an ambience towards reutilization of industrial waste that creates environmental pollution to the society visa-vis reducing the cost of concrete due to replacement of cement by fly ash.

9 illus, 4 tables, 8 ref

007934   Ling S Y;Yong L C (Civil Engineering Dep, College of Engineering, Tenaga Nasional Univ, Malaysia, Email: yueling.sim@gmail.com) : Palm biodiesel contaminated sand-steel interface testing with direct simple shear apparatus. Int J civ struct Engng 2012, 3(1), 227-38.

Describes the use of a laminar-ring direct simple shear apparatus that was employed to test interface properties with the soil specimen contained in a stacked metal rings. A series of interface tests between steel and palm biodiesel contaminated soils were conducted using the developed apparatus. The mining sand samples contaminated with different palm biodiesel contents were tested on relatively smooth and rough steel surfaces. Parameters investigated include palm biodiesel content, surface roughness and normal stress. The experimental results show that the contribution of palm biodiesel content to interface shear strength is significant. Interface shear strength increases with the increase of palm biodiesel content. Applied normal stress and surface roughness have remarkable influence on the interface shear strength. The decrease in interface shear strength due to an increase in palm biodiesel content is observed. Soil dilatancy is observed for clean mining sand but as the palm biodiesel content is increased, higher soil dilatancy is obvious in lower normal stresses. The rate of increase of soil dilatancy is greater in higher palm biodiesel content than in lower palm biodiesel content. They also indicated that the surface roughness has a significant effect on the interface shear strength at a given palm biodiesel content and normal stress level. With respect to surface roughness and palm biodiesel content, three shearing modes are likely to take place: shearing at the interface, shearing within the soil and an intermediate mode involving these two types of shearing. For the second mode, the shear strength at the soil-rough steel interface is likely to be greater than the shear strength of the sand, particularly for sand with higher palm biodiesel content.

9 illus, 2 tables, 26 ref

007933   Kushwaha J;Pawan Kumar V;Sinnur K H (NO, Advanced Systems Laboratory, Hyderabad-500 058, Email: juhikushwaha17@yahooo.com) : Development and evaluation of carbon-carbon threaded fasteners for high temperature applications. Def Sci J 2012, 62(5), 348-55.

Carbon-Carbon (C-C) threaded fasteners have been developed for joining C-C composites experiencing temperature above 1500 °C. The fasteners were fabricated from spun yarn graphitized carbon fabric through resin route and from needle punched carbon felt through pitch route techniques. The preforms were processed with multiple cycles of impregnation, carbonisation, and graphitisation up to densities of 1.78 gem^-3 and 1.90 gem^-3. Densification process cycles were repeated to obtain composites with reduced porosity and improved thermo-mechanical properties. Material evaluation of C-C fasteners is discussed and compared with existing graphite fasteners used in industrial and aerospace sectors. Scanning electron microscopy was also carried out to study microstructure of fractured specimens.

8 illus, 4 tables, 10 ref

007932   Kumbhar P D;Murnal P B (Civil Engineering Dep, Rajarambapu Institute of Technology, Rajaramnagar, Sakharale, Dist. Sangli, Maharashtra, Email: kumbharpd@rediffmail.com) : Assessment of suitability of existing mix design methods of normal concrete for designing high performance concrete mixes. Int J civ struct Engng 2012, 3(1), 158-67.

Objective of proportioning a concrete mix is to obtain relative quantities of ingredients for the most economical mix that meets the minimum criteria of strength, workability, durability, aggregate characteristics and economy. A number of standard mix proportioning methods are available for conventional normal strength concrete (NSC). Concrete with a compressive strength less than 50 MPa is regarded as normal strength concrete (NSC). Mix proportioning of high performance concrete (HPC) is a more critical process than that of NSC in view of higher powder content and requirement of low water-binder ratio. Existing mix design methods of NSC such as Bureau of Indian Standards (BIS), Department of Environment (DOE), American Concrete Institute (ACI) are not directly applicable for designing HPC mixes due to several reasons, primarily due to the presence of mineral admixtures. It is felt that the mix design procedures for HPC can be based on these available methods but with suitable modifications. Therefore, this paper examines the suitability of these methods of mix design through experimental procedures on mixes containing mineral admixtures like micro-silica and fly ash. The results indicate that some of these methods can be applied for making HPC mixes with certain modifications in the proportions of aggregates and also in dosages of specific types of superplasticizer for achieving desired workability and strength properties.

2 illus, 10 tables, 17 ref

007931   Ibrahim A M;Mohaisen S K;Ahmed Q W (NO, College of Engineering Diyala Univ, Iraq, Email: amereng05@yahoo.com) : Finite element modeling of composite steel-concrete beams with external prestressing. Int J civ struct Engng 2012, 3(1), 101-16.

Nonlinear finite-element analyses have been carried out to investigate the, behavior up to failure of simply supported composite steel-concrete beams with external prestressing, in which a concrete slab is connected together with steel I-beam by means of headed stud shear connectors, subjected to symmetrically static loading. ANSYS computer program (version 12.0) has been used to analyze the three dimensional model. This covers: load deflection behavior, strain in concrete, strain in steel beam and failure modes. The nonlinear material and geometrical analysis based on Incremental-Iterative load method, is adopted. Three models have been analyzed to verify its capability and efficiency. The results obtained by finite element solutions have shown good agreement with experimental results.

32 illus, 1 table, 10 ref

007930   Hwang A;Seong W (NO, Koje College, Gyeongsangnam-do, Korea, Email: aromhwang@koje.ac.kr) : Simultaneous mapping and localisation for small military unmanned underwater vehicle. Def Sci J 2012, 62(4), 223-7.

Paper proposes a simultaneous localisation and mapping (SLAM) scheme which is applicable to small military unmanned underwater vehicles (UUVs). The SLAM is a process which enables concurrent estimation of the position of UUV and landmarks in the environment through which the vehicle is passing. An unscented Kalman filter (UKF) is utilised to develop a SLAM suitable to nonlinear motion of UUV. A range sonar is used as a sensor to collect the relative position information of the landmark in the environment in which the UUV is navigating. The proposed SLAM scheme was validated through towing tank experiments about two degrees of freedom motion with UUV motion simulator and real range sonar system for small UUV. The results of these experiments showed that proposed SLAM scheme is capable of estimating the position of the UUV and the surrounding objects under real underwater environment.

4 illus, 3 tables, 10 ref

007929   Heeralal M;Sreedhar M V S;Yakaiah B (Civil Engineering Dep, National Institute of Technology, Warangal, Andhra Pradesh, Email: heeralal.mudavath@gmail.com) : Investigations on dynamic response of coir reinforced fly ash stabilized black cotton soil. J Envir Res Dev 2011, 6(2), 212-21.

Geo-technical engineers all over the world face challenges during construction of various structures in expansive soil deposits. Attempts have been made by several researchers to suggest solutions to these problems based on different concepts. In the design of flexible pavements, the importance of coefficient of elastic uniform compression is being appreciated world over. The conventional CBR based methods are not accounting the performance of pavements particularly in terms of development of ruts and their propagation. This study combines the need for not only stabilizing the B.C. Soil but also improving its dynamic performance of pavements. The basic objective of this study is to investigate the role of coir on resilience behaviour of the fly ash stabilized B.C. Soil. Fly ash which is an industrial waste byproduct generated by thermal power plants is used as stabilizing agent and coir (a product from coir industry) is used as reinforcing material to improve black cotton soils to control swell and to improve resilience. The optimum percentage of fly ash (type-F) for stabilization of the BC soil used in this investigation is found as 20%. The same combination is adopted in this study. To investigate the effect of coir on resilience behaviour, content of coir is varied at 0.5%, 1.0%, 2.0% and 5.0 % by weight of soil solids. Coir content with the aspect ratios of 50, 100 and 150 are adopted. The coefficient of elastic uniform compression for various combinations is found by conducting laboratory cyclic plate load tests. The present study revealed that the addition of randomly distributed coir improved the coefficient of elastic uniform compression and hence improved the dynamic performance of the pavement was observed.

4 illus, 2 tables, 16 ref

007928   Gutch P K;Srivastava R K (NO, Defence Research and Development Establishment, Gwalior-474 002, Email: pkgutch@rediffmail.com) : Gas chromatographic retention indices of 2-chlorobenzylidenmalononitrile and its analogues. Def Sci J 2012, 62(5), 319-23.

Riot control agent, 2-chlorobenzylidenemalononitrile (CS) and its analogues have both skin irritating and lacrymating properties. Herein, authors report retention indices (Rl) of CS and its thirteen analogues relative to the homologues n-alkanes series. These values are determined on nonpolar BP-1 and polar BP-10 capillary column under programmed temperature and isothermal chromatographic condition. The analogues differ in substitution at ortho or para position of phenyl ring and retention indices are found to vary according to the nature of the substituent.

5 tables, 18 ref

007927   Gupta S M;Grover A;Ahmed Z (NO, Defence Institute of Bio-Energy Research, Haldwani-263 139, Email: smg555@rediffmail.com) : Identification of abiotic stress responsive genes from Indian high altitude Lepidium latifolium L.. Def Sci J 2012, 62(5), 315-8.

Abiotic stresses are major environmental factors that periodically account for significant loss in crop productivity. In order to improve the abiotic stress tolerance in vegetable crops through transgenic approaches, authors isolated and cloned six up-regulated, LlaDREBlb (JN214345), LlaGPAT(JN398166), LlaNAC (FJ423495), LlaClPK (FJ423496), LlaPRS (GQ853409) and LlalPK (FJ487575) and two down-regulated LlaRan (JN214347) and LlaDRT(JN214346) abiotic stress responsive genes from Indian high altitude Lepidium latifolium L. plant that that may be used for abiotic stress-tolerance engineering upon functional validation.

^ssc1 illus, 2 tables, 20 ref

007926   Gupta S K;Siva Prasad G;Nanda Kishore J (NO, Defence Electronics Research Laboratory, Hyderabad-500 005, Email: jnandakishore@yahoo.co.in) : Electronic warfare simulation-based on service oriented architecture. Def Sci J 2012, 62(4), 219-22.

Realisation of service oriented architecture (SOA) is embodied in the accomplishments of various simulation applicable functions in the form of service encapsulation and the interconnection and interoperation of services. In this paper, an electronic warfare (EW) simulation is structured to SOA and achieved the effect of dynamic sharing and reusability. As a proof of concept, a radar electronic support (ES) simulator, which intercepts and classifies radar signals is designed and explained in this paper.

5 illus, 16 ref

007925   Gupta R C;Thomas B S;Gupta P (NO, Malaviya National Institute of Technology, Jaipur, Rajasthan, Email: bstblessen@yahoo.com) : Utilization of copper slag and discarded rubber tyres in construction. Int J civ struct Engng 2012, 3(2), 271-81.

This paper is a part of an experimental investigation to study the structural characteristics of concrete using various combinations of copper slag and discarded rubber tyres for the partial replacements for fine and coarse aggregates. The copper slag and rubber tyres are mixed with natural aggregates to prepare concrete. The concrete mix of grade M30 (i.e. 1:1.38:3.23) was adopted with water cement ratio 0.5. Concrete cubes, cylinders and beams were casted with varying contents of rubber pieces (as coarse aggregate) and copper slag (as fine aggregate). The test specimens were cured and tested for compressive strength, split tensile strength, flexural strength, water absorption and ultrasonic pulse velocity as per IS specifications. It was found that the strength of concrete is increased due to the presence of copper slag. When the rubber tyre pieces are replaced up to definite percentage of coarse aggregates, there is no decrease in strength. The concrete with copper slag and the rubber tyre pieces could be useful for all structures.

13 illus, 12 tables, 11 ref

007924   Gupta M K;Rana P (EE Dep, Jagannath Univ, Jaipur, Email: mugupta72@gmail.com) : Power flow analysis with TCSC using newton-raphson method. Int J latest Technol Engng Mgmt appl Sci 2013, 2(5), 11-7.

In this paper, Newton Raphson power flow algorithm in matlab incorporating TCSC is presented. Overview of the different static load models for distribution system has been covered and included in N-R power flow. This paper present effect of TCSC level on transmission system voltage profile for different types of static load types in which active and reactive power vary with its terminal voltages with as in exponential form, variation of the load voltage for different sizes of TCSC are simulated with 5 bus. It has also been observed that the proposed algorithm can be applied to larger systems and does not suffer with computational difficulties.

19 illus, 5 tables, 21 ref

007923   Guang-yan H;Shun-shan F;Wang F;Tong Z (NO, Beijing Institute of Technology, Beijing-100 081, China, Email: huanggy@bit.edu.cn) : Optical design theory for focused fragmentation warhead. Def Sci J 2012, 62(4), 205-11.

Focusing the dispersing direction of fragments with high-accuracy is one key issue in the design of advanced focused fragmentation warhead for the application of aerial defence and antimissile. The similarity of mechanism between the focusing of geometrical optics and focusing of fragments is analysed in details, and it is proved that the driving direction of warhead fragment can be controlled according to the theory of geometrical optics. A new design model and method for Focused fragmentation warhead is obtained. The design is preliminary proved to be efficient by some tests, and it is found that 85 per cent of total fragment of the warhead can be focused within the designed focusing zone, which is an improvement to the 70 per cent obtained by other methods.

12 illus, 11 ref

007922   Goyal V;Khandelwal N (NO, International Institute of Management, Engineering & Technology, Jaipur, Email: goyal.vishakha0@gmail.com) : Image demosaicing and reconstruction of bayer-patterned color images from color CCD samples using high-quality linear interpolation. Int J latest Technol Engng Mgmt appl Sci 2013, 2(5), 18-25.

Simplified color image formation model is used to construct an algorithm for image reconstruction from CCD sensors samples. The proposed method involves two successive steps. The first is motivated by Cok's template matching technique, while the second step uses steerable inverse diffusion in color. Classical linear signal processing techniques tend to over smooth the image and result in noticeable color artifacts along edges and sharp features. The question is how the different color channels should support each other to form the best possible reconstruction. Our answer is to let the edges support the color information and the color channels support the edges, and thereby achieve better perceptual results than those that are bounded by the sampling theoretical limit. This paper introduces a new interpolation technique for Demosaicing of color images produced by single-CCD digital cameras. Shows that the proposed simple linear filter can lead to an improvement in PSNR when compared to a recently introduced linear interpolator. The proposed filter also outperforms most nonlinear demosaicing algorithms, without the artifacts due to nonlinear processing, and a much reduced computational complexity.

9 illus, 26 ref

007921   Goswami S;Krishnan N R;Mukesh;Swarnkar S; Mahajan P (Directorate of Management Information System & Technologies, DRDO, New Delhi, Email: sumit_13@yahoo.com) : Reducing attack surface of a web application by open web application security project compliance. Def Sci J 2012, 62(5), 324-30.

Attack surface of a system is the amount of application area that is exposed to the adversaries. The overall vulnerability can be reduced by reducing the attack surface of a web application. In this paper, we have considered the web components of two versions of an in-house developed project management web application and the attack surface has been calculated prior and post open web application security project (OWASP) compliance based on a security audit to determine and then compare the security of this Project Management Application. OWASP is an open community to provide free tools and guidelines for application security. It was observed that the attack surface of the software reduced by 45 per cent once it was made OWASP compliant. The vulnerable surface exposed by the code even after OWASP compliance was due to the mandatory access points left in the software to ensure accessibility over a network.

2 illus, 1 table, 20 ref

007920   Golmaei S H;Boulon M (NO, Sari Agriculture Sciences and Natural Resources Univ, Sari, Iran, Email: h.golmaei@sanru.ac.ir) : Comparison between experimental and finite element modeling data for triaxial undrained cyclic tests in compression on HOSTUM sand. Int J civ struct Engng 2012, 3(2), 429-42.

Finite elements modeling data is fitted to the results of experimental undrained monotonic and cyclic isotropic triaxial tests. The model can predict the accumulation strain /stress, and pore pressure in undrained state. For determination of material constants, the first cycle (loading-unloading) is performed step-by-step, using Hardening-Soil model for undrained soil, then for the cycles greater than one, the Behavior of the soil is simulated as a pseudo creep (Soft-Soil-Creep model, here) where the number of cycles N is considered equivalent time. The prediction of model is compared with experimental results from monotonic and cyclic undrained isotropic triaxial tests. Good correlation exists between predicted and experimental response.

11 illus, 3 tables, 12 ref

007919   Ghugal Y M;Kulkarni S K (Applied Mechanics Dep, Government Engineering College, Aurangabad - 431005, Email: ghugal@rediffmail.com) : Effect of aspect ratio on transverse displacements for orthotropic and two layer laminated plates subjected to non-linear thermal loads and mechanical loads. Int J civ struct Engng 2012, 3(1), 186-96.

Transverse displacements of orthotropic and antisymmetric two layer cross-ply laminated plates subjected to non-linear thermal load in combination with transverse mechanical load is presented using trigonometric shear deformation theory for various aspect ratios. The in-plane displacement field uses sinusoidal function in terms of thickness co-ordinate to include the shear deformation effect. The theory satisfies the shear stress free boundary conditions on the top and bottom surfaces of the plate. The present theory obviates the need of shear correction factor. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. The results of present theory are compared with those of classical plate theory, first order shear deformation theory and higher order shear deformation theory.

3 illus, 3 tables, 21 ref

007918   Ghugal Y M;Dahake A G (Applied Mechanics Dep, Govt. College of Engineering, Karad, Email: ghugal@rediffmail.com) : Flexure of thick beams using refined shear deformation theory. Int J civ struct Engng 2012, 3(2), 321-35.

Trigonometric shear deformation theory for flexure of thick beams, taking into account transverse shear deformation effects, is developed. The number of variables in the present theory is same as that in the first order shear deformation theory. The sinusoidal function is used in displacement field in terms of thickness coordinate to represent the shear deformation effects. The noteworthy feature of this theory is that the transverse shear stresses can be obtained directly from the use of constitutive relations with excellent accuracy, satisfying the shear stress free conditions on the top and bottom surfaces of the beam. Hence, the theory obviates the need of shear correction factor. Governing differential equations and boundary conditions are obtained by using the principle of virtual work. The thick isotropic beams are considered for the numerical studies to demonstrate the efficiency of the theory. It has been shown that the theory is capable of predicting the local effect of stress concentration due to fixity of support. The fixed isotropic beams subjected to parabolic and cosine loads are examined using the present theory. Results obtained are discussed critically with those of other theories.

12 illus, 3 tables, 22 ref

007917   Ghahderijani M;Almassi M;Fami H S;Moghadasi R (Agricultural Mechanization Dep, Science and Research Branch, Islamic Azad Univ, Tehran, Iran, Email: ghahderijani2009@gmail.com) : Consideration the possibility of utilizing wind energy for optimum using in rural area (agricultural and domestic consumptions) Case study: Qazvin province of Iran. Int J civ struct Engng 2012, 3(2), 282-93.

Based on the present pattern of resource utilization in country, Iran, obviously in not far future not only is able to export energy (in form of petroleum) but also will be in group of countries as a main and whole sale importer of energy. In any case, the main sources of energy in Iran is fossil sources and considering the increase in its demand process, would cause country many problems on advancement of social and economic sections in future. On the one hand, undoubtedly economic expansion is not possible without agricultural and rural development in Iran. Therefore, exploitation of wind energy is possible, according to considerable potential of this kind of renewable energy in different parts of country among others, rural and agricultural districts. On the other hand, using of wind turbines for the purpose of generating electricity or carrying water to farms and gardens in windy and susceptible districts can generate required electricity for the use of domestic and rural and agricultural parts without creating environmental pollution and moreover, would be effective in decreasing energy costs in prolonged time. In this research, potential meter (measuring) of wind energy utilization has been done for the purpose of recognizing the possibility of applying wind energy to generate a percentage of rural energy consumptions of Kouhin district in Qazvin province. To this end, information of standard wind meter station in this district was used by recording speed and point data in short time spaces (10 minutes) during 5 years. The results of this research showed that this district with average of annual speed of 6.7 m s-1 in height of 10 meter and power density of 800 Wm-2 has suitable conditions for settling of wind turbines to generate the electricity for domestic consumptions in rural and agricultural irrigation operations. Also, in this essay, usage of geographical information system (GIS) in farm management, applying of renewable wind energy, localization and necessity of wind energy exploitation based on existed information have been discussed.

6 illus, 2 tables, 19 ref

007916   Fahmy W S;Heneidy E A L;Ali E E;Agwa I S (NO, Faculty of Petroleum and Mining Engineering, Suez Canal Univ, Suez, Egypt, Email: erfanlh@yahoo.com) : Performance of concrete containing crushed waste concrete exposed to different fire temperatures. Int J civ struct Engng 2012, 3(1), 9-22.

Recycled aggregate obtained from the construction and demolition waste has currently received increasing attention, due to its potential to be used in environmentally friendly concrete structures. Further, the deficiency of natural aggregates, shortage of dumping sites, increase in transport cost and environmental pollution lead to use of recycled aggregate as a substitute material in the production of concrete in many countries. This experimental study demonstrates the properties of concrete containing crushed waste concrete exposed to different fire temperatures. In the experimental work, the fresh concrete properties (slump test) and the hardened concrete properties, (compressive strength, splitting tensile strength, flexural strength and modulus of elasticity) were carried out. A total of thirty concrete mixes with different cement contents (300, 350, and 400 Kg/m³) at w/c ratio (0.5) were made and the percentage of replacement of natural coarse aggregate by fired recycled coarse aggregate at fire temperatures (300,600 and 800°C) for fire duration (2) hours was (0, 25, 50 and 100%). In the process of mixing, equal consistence among all concrete mixes was achieved. The obtained results indicate that the recycled coarse aggregate subjected to fire can successfully be used for making structural concrete.

6 illus, 6 tables, 12 ref

007915   Dutta D;Chakrabarty S;Bose C;Ghosh S (Civil Engineering Dep, Jadavpur Univ, Kolkata-700 032, Email: ddebabrata83@gmail.com) : Evaluation of Geopolymer properties with temperature imposed on activator prior mixing with fly ash. Int J civ struct Engng 2012, 3(1), 205-13.

Experiment has been performed to assess the impact of temperatures on activator before mixing. In this program, a set of activators having 8% of Na₂O by weight of fly ash were subjected to different temperatures ranging from 15 C to 90°C, for a period of 24 hours and 48 hours. The performances of geopolymer were investigated on the basis of workability and strength. Scanning Electron Microscope (SEM) along with EDAX was also conducted to predict microstructural and mineralogical changes. Geopolymer paste prepared with the activator, which was subjected to a temperature 45°C for duration of 48 hours, showed mechanical property.

7 illus, 3 tables, 10 ref

007914   Dubey S K;Doni A;Kute S Y (Civil Engg. Dept, S.S.V.P.S BSD College of Engg., Dhule, Email: dubeydhule@rediffmail.com ) : Ultimate strength of epoxy repaired reinforced concrete frames. Int J civ struct Engng 2012, 3(2), 443-50.

Due to tremor buildings are damaged partly or totally, Predominantly soft storeys are mostly affected. In. general such structures are repaired and used again. In this regard, an experimental investigation was planned and conducted for bare RC. (Reinforced concrete) frames up to collapse and then such collapsed frames repaired with epoxy res in were tested to obtain ultimate load and results are compared. All these frames were tested up to collapse and subjected to only horizontal loads to obtain an effective and possible solution for retrofitted frames which can be reused for soft storeys. In comparison to bare R.C, frame, epoxy repaired frames have comparable lateral load capacity For the similar load epoxy repaired frames have maximum deformation under control in comparision to bare R.C. frames.

5 illus, 2 tables, 12 ref

007913   Dubey R;Pardeep Kumar (Civil Engineering Dep, NIT Hamirpur, Himachal Pradesh, Email: rahul0051@indiatimes.com) : Effect of superplasticizer dosages on compressive strength of self compacting concrete. Int J civ struct Engng 2012, 3(2), 360-6.

Self-compacting concrete has to fulfil contradictory requirements of high flowing ability when it is being cast and high viscosity when it is at rest, in order to prevent segregation and bleeding. These requirements make the use of mineral and chemical admixtures essential for self-compacting concrete. High flowing ability is achieved using superplasticizers, while stability against segregation is achieved either by using a large quantity of fine materials, or by using appropriate viscosity modifying agents. This paper presents the results of an experimental research carried out to investigate the effect of dosages of superplasticizer on compressive strength of self- compacting concrete.

3 illus, 4 tables, 13 ref

007912   Dubey A;Shami T C (NO, Defence Materials and Stores Research and Development Establishment, Kanpur-208 013, Email: dubey.drdo@gmail.com) : Metamaterials in electromagnetic wave absorbers. Def Sci J 2012, 62(4), 261-8.

Stealth technology in terms of absorption of electromagnetic waves is a most valuable research area for military purposes. Development of radar absorbing materials (RAM) had been actively researched for a quite long time. In the RAM design, weight, thickness, absorptivity, environmental resistance and mechanical strength are the key factors and therefore development of RAM with low density and high strength is a challenging task. As an alternative, research interest has shifted towards radar absorbing structures (RAS) and metamaterial is one of the lucrative options for the development of RAS. Metamaterials are a new class of ordered composites that exhibit exceptional electromagnetic properties not readily observed in nature. Built from microstructure that is small compared to wavelength of operation, metamaterials can be designed with effective permittivity and permeability values that can be large or small or even negative at any selected frequency. In this review paper, we first place the stealth technology in brief and then concept of metamaterials in context of conventional materials. We then discuss reflection theory of metamaterials from stealth point of view. Next section deals with recent progress towards its application as electromagnetic absorbers and future prospects especially in higher frequency region.

^iia6 illus, 16 ref

007911   Dinesh S;Mohd Faudzi M;Zainal Fitry M A (NO, Science and Technology Research Institute for Defence, Malaysia, Email: dinesh.sathyamoorthy@stride.gov.my) : Evaluation of the effect of radio frequncy interference on global positioning system (GPS) accuracy via GPS simulation. Def Sci J 2012, 62(5), 338-47.

In this study, Global positioning system (GPS) simulation is employed to study the effect of radio frequency interference (RFI) on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both GPS receivers employ the GPS LI coarse acquisition (C/A) signal. It was found that with increasing interference signal power level, probable error values of the GPS receivers increase due to decreasing carrier-to-noise density (C/N_o) levels for GPS satellites tracked by the receivers. Varying probable error patterns are observed for readings taken at different locations and times. This was due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over location and time, resulting in GPS accuracy being location/time dependent. In general, the highest probable error values were observed for readings with the highest position dilution of precision (PDOP) values, and vice versa.

10 illus, 4 tables, 46 ref

007910   Dass Goel M;Matsagar V A;Gupta A K;Marburg S (NO, CSIR-Advanced Materials and Processes Research Institute, Bhopal-462 064, Email: mdgoel@ampri.res.in) : Abridged review of blast wave parameters. Def Sci J 2012, 62(5), 300-6.

In case of blast loading on structures, analysis is carried out in two stages, first the blast loading on a particular structure is determined and second, an evaluation is made for the response of the structure to this loading. In this paper, a review of the first part is presented which includes various empirical relations available for computation of blast load in the form of pressure-time function resulting from the explosion in the air. Different empirical techniques available in the form of charts and equations are reviewed first and then the various blast wave parameters are computed using these equations. This paper is providing various blast computation equations, charts, and references in a concise form at a single place and to serve as base for researchers and designers to understand, compare, and then compute the blast wave parameters. Recommendations are presented to choose the best suitable technique from the available methods to compute the pressure-time function for obtaining structural response.

8 illus, 21 ref

007909   Choobbasti A J;Shooshpasha E;Farrokhzad F (Civil Engineering Dep, Babol Technology Univ, Babol, Mazandaran, Iran, Email: FarzadFarokhzad@yahoo.com) : 3-D modeling of soil's unsaturated depth using artificial neural network (Case study of Babol). Int J civ struct Engng 2012, 3(1), 23-30.

Study of unsaturated soil is essential for engineers who construct dams, tunnels, water conveyance channels, mines, and other structures. Groundwater must also be taken into account when devising measures to control ground settlement or subsidence caused by dewatering. An artificial neural network (ANN) is a mathematical model or computational model that is inspired by the structure or functional aspects of biological neural networks. In this study the authors used ANN as a non-linear statistical data modelling tool for assessing the 3-D model of soil's unsaturated depth. Based on the obtained results, it can be stated that the trained neural network is capable in 3-D modelling of soil's unsaturated depth with an acceptable level of confidence and it should be added that the mentioned ANN is useful to model complex relationships between input and outputs or to find patterns in data for prediction of ground water table in study area.

3 illus, 2 tables, 16 ref

007908   Chee-Ming C;Yoshiaki K;Takaaki M (NO, Tun Hussein Onn Malaysia Univ, Malaysia, Email: cheeming76@live.com) : Correlation between unconfined compressive strength and mixing quality of solidified clay. Int J civ struct Engng 2012, 3(2), 408-17.

The solidification of soft soils with cement is a well established practice. The originally soils with limited strength and high compressibility can be effectively improved to serve most civil engineering applications. Nonetheless effectiveness of the solidification method depends on various factors, where the mixing quality is arguably one of the most important. Mixing quality of the soil-cement mixture is directly influenced by the cement dosage as well as mixing frequency or cycles. In this laboratory study, Kawasaki clay was treated with a range of cement contents (i.e. 8-16.5%) at the fixed water/cement (W/C) ratio of 10. The corresponding mixing water contents were 1.5-3.0 times the liquid limit of the clay. Also, cement powder was introduced in single, double or triple layers in the cylindrical specimens measuring 50 mm diameter and 100 mm height. Mixing cycles were varied at 5, 50 and 100 times of scooping motion using a spatula. In summary, it was found that the number of cement layer played limited role in the uniformity of mixing, where W/C ratio and the mixing cycles remained the dominant factors.

5 illus, 2 tables, 11 ref