Unsteady flow of a fluid particle suspension between two parallel plates suddenly set in motion with same speed

M. sunitha, B. Shanker and G. Shantha

In this paper we consider a fluid particle suspension filling the region between two rigid parallel plates, assuming that initially the plates as well as the fluid are at rest. The unsteady flow generated by moving suddenly the two plates in their own plane is studied. Taking the Laplace Transform of the equations of motion with the appropriate central and boundary conditions, the Laplace Transforms of the fluid velocity, dust particle velocity, volume flux of the fluid and volume flux of the dust particles across a plane normal to the flow per unit width and the skin friction are obtained. Numerical Inversion is carried out using the procedure of Honig and Hirdes [3] and their variation is studied with respect to diverse fluid parameters, space variable and time. The variation of the flow field quantities is studied numerically and the results are presented through graphs.

Data transfer strategy for multiple destinationnodes in virtual private networks

C. Mahalakshmi and M.Ramaswamy

The paper attempts to design a data transfer scheme suitable for a host of receiver nodes in the wired infrastructure of a Virtual Private Network (VPN). The primary focus echoes a simultaneous data transfer strategy in the paths that inter connect a single source and multiple destinations in a wired VPN and offer a promising service similar to that of a dedicated private network. The methodology caters to extricate a suitable routing pattern to arrive at the preferred user across a service provider over specific time frames through an optimum use of bandwidth. It forges to acquire the best values of performance indices for that path which uses minimum bandwidth in each mission. The scheme be-hives a facility to re-route the data through an alternate path on the occurrence of a link failure to reach the desired destination. The performance of the routing mechanism simulated using a chosen network in the hose model serves to highlight the viability of the proposed approach to suit the befitting requirements in the field of data transfer.

Damping low frequency oscillations in power systems using iteration particle swarm optimizations

J. Usman, M. W. Mustafa, J. J. Jamian and G. Aliyu

The major concern in power systems has been the problem of low frequency oscillations (LFO) that results in the reduction of the power transfer capabilities. The applications of power system stabilizers (PSS) are commonly employed to dampen these low frequency oscillations. The parameters of the PSS are tuned by considering the Heffron-Phillips model of a single machine infinite bus system (SMIB). Tuning of these parameters for the system considered can be done using iteration particle swarm optimization (IPSO) technique in this paper; mainly the lead lag type of PSS was used to damp these low frequency oscillations. The proposed technique (IPSO)'s capabilities are compared with the traditional PSO and genetic algorithm (GA) technique in terms of parameter accuracy and computational time. Also the results of nonlinear simulations and eigenvalue analysis reveals that, the IPSO is much better optimization technique as compared to traditional PSO and GA.

Simulation of indoor air flow for a room with windows at their adjacent walls under various wind flow direction using CFD

D. Prakash and P. Ravikumar

The present paper is about to study the effect of wind direction on thermal comfort in a office room with windows at their adjacent walls. As a preliminary work, a suitable turbulence model was selected by analyzing the various turbulence models like Standard K-e, Renormalization-group (RNG) K-e and Realizable K-e model and their closeness to the experimental results are predicted. From the preliminary study, Standard K-e model is selected as a suitable turbulence model for this thermal comfort study. The CFD simulation is also checked for grid independence test. Secondly, the effect of wind direction on thermal comfort was analyzed by including the fluctuation of wind direction. The CFD simulated mass flow rate for all wind directions are compared with the network work model and the maximum discrepancy obtained is 9.97% which is within the accepted level. The indoor air flow pattern, temperature distributions, are predicted and these results are very much useful to identify the most comfort and un comfort zones prevailed inside the room for various wind directions.

Stability analysis of paralleled single ended primary inductance converters

A. Ezhilarasi and M. Ramaswamy

Abstract:

The small signal model offers an encouraging scope to examine the steady state stability and there from establish a viable operating range for power converters. The theory of Eigen value analysis facilitates to predict the stable operation and introduce appropriate measures to regain its equilibrium in the event of an exigency. The paper attempts to develop a methodology through the use of compensators to ensure that the Eigen values of the characteristic equation of the converter lie in the left half of the S plane. It includes the philosophy of a master slave current sharing mechanism in the scheme to arrive at satisfactory servo and regulatory results. The performance of the parallel connected SEPIC (Single Ended primary Inductance Converters) system is evaluated using time and frequency domain plots on a MATLAB platform to project the suitability of the proposed approach in practical applications.

Interaction effect of space frame-strap footing-soil system on forces in superstructure

Vivek Garg and M.S. Hora

Abstract:

The conventional method of building frame analysis assumes that columns are resting on unyielding supports. In reality, the supporting soil strata deforms unevenly under the action of loads, which causes redistribution of forces in the frame members and stresses in the supporting soil media. In the past, many researchers investigated and emphasized the need of soil-structure interaction analysis. There may exist a situation where column(s) of a building are located near adjoining property line. In this situation, an eccentric footing is generally provided. This causes angular rotation in such individual footings due to moment developed by eccentric loading. The strap beams may be provided under such circumstances in order to control the rotation within permissible values. However, in India the normal practice is to provide individual column footings without strap beams. In the present work, the interaction analysis of a three-bay three-storey RCC space frame- footing-strap beam-soil system is carried out to investigate the interaction behavior using the finite element method. The frame, foundation and supporting soil mass are considered to be linear elastic and to act as a single compatible structural unit for more realistic analysis. The analyses have been carried out to evaluate the axial force and moment in columns, bending moments and shear force in floor, plinth and strap beams. The comparison is made between the non-interaction and interaction analyses. The emphasis is made on the necessity of interaction analysis using strap beams. The inclusion of strap beams in the foundation will prevent failure/distress of the structure likely to be caused by heavy moments induced when only eccentric isolated footings are used.

Web services represent the class of Service Oriented Architecture (SOA) based applications with a hugely diversified domain. Web service regression testing presents a set of challenges to the tester which need to be overcome in order to provide a reliable performance of the desired application. Code based regression testing approaches present a lot of difficulties as the tester needs to know the code which is in most cases not possible. In this paper, we address a UML based regression testing method independent of the code using test cases generated from use cases in the context of a case study.

Abstract:

Continuous monitoring of strength gain in fresh cementitious system is an important assessment for determining the long term strength gain properties in concrete. The present study is aimed to evaluate the setting characteristics of fresh cementitious systems containing ordinary Portland cement (OPC) and flyash blended cement. Also, the influence of accelerators on the rate of strength gain in flyash concrete was studied systematically. A fabricated plexiglass mould was used to monitor the setting properties of fresh cement paste using an ultrasonic pulse velocity at different time intervals for different cementitious systems. The test results indicated that the pozzolanic reaction of flyash in cement was enhanced with the addition of accelerator. Also, a drastic reduction in setting time was noticed for large replacement of flyash (40%) at increased dosage of accelerator (upto 3%). However, the rate of hardening was found to be consistently higher for an optimum flyash replacement (30%) in cement with1% of accelerator dosage and exhibited a highest compressive strength of 42.21 MPa. It can also be concluded from the ultrasonic pulse velocity test results that the cementitious system containing 20% flyash in cement with the addition of 3% accelerator dosage recorded a good improvement in the early age strength.

Abstract:

Geopolymer based cementitious binder is one of the recent findings in the emerging concrete technology. The present study investigates the setting and strength properties of geopolymer mixtures containing binary combinations of bentonite-flyash, bentonite-cement, bentonite-silica-fume and ternary blends of bentonite-flyash-lime. The effect of lime and alkali activator (sodium hydroxide) on the geopolymerisation of bentonite was studied systematically. The experimental results showed that the initial and final setting time of binary mixtures containing bentonite and silica fume (5%) with alkali activator (NaOH) showed early setting time of 30 minutes compared to other geopolymer mixtures. It was also noted that compressive strength of ternary mixtures containing 40% bentonite, 30% flyash and 30% lime (M16) attained the maximum strength of 24.74 MPa at 28 days. The highest rate of strength gain was observed at early curing period (7 days) for the ternary mixtures (M14) consisting of 80% bentonite, 10% flyash and 10% lime compared to other mixtures. It can be realized from the experimental study that, geopolymerisation reaction was effective for the specimens cured at 100°C hot air oven.

Rosangela Naomi Inui - Kishi, Luciano Takeshi Kishi, Simone Cristina Picchi, José Carlos Barbosa, Maria Teresa Olivério Lemos, Jackson Marcondes and Eliana Gertrudes de Macedo Lemos

Abstract:

Plant Growth Promoting Rhizobacteria (PGPR) has been used as a biofertilizer, bringing benefits to agriculture as Phosphorus Solubilizing Bacteria (PSB), indole-acetic acid (IAA) producers, and with other activites. The goal of this report was the identification of PGPR from soils under sugarcane crops by 16S rRNA sequencing, and the evaluation of the ability of phosphorus solublizing and IAA production by biological assays. The isolates of this work were obtained from three areas of sugarcane crop from São Paulo State, Brazil. All isolates came from rhizosphere soil, and in a total of 60 isolates just 10 have showed high ability in phosphorus solubilizing. The selection of PSB may be done by phenotypic and/or genotypic characterization. Among ten isolates Enterobacter sp. (FJ890899), Entrobacter homaechei subsp. verschuerennii (FJ890998), Burkholderia sp. (FJ890895), and Labrys portucalensis (FJ890891) were able to IAA production.

Behavior of high performance fiber reinforced concrete columns

Wasan Ismail Khalil, Ikbal Naeem Gorgis and Zeinab Raad Mahdi

Abstract:

An experimental program was carried out in this research to investigate the behavior of square short high performance concrete columns with and without steel fiber under concentric compression loading. The effect of concrete strength, percent of longitudinal reinforcement, spacing of lateral confined stirrups, volumetric steel fiber ratio and aspect ratio of steel fiber on the uniaxial behavior of reinforced HPC columns were presented and discussed. The results show that adding discrete fibers to HPC mixtures in reinforced concrete columns not only prevents the premature spalling of the concrete cover but also increases the strength and ductility of the axially loaded reinforced columns. More confinement is required in HPC columns in comparison with that normal strength concrete to achieve the desired post-beak deformability.

Experimental investigation of performance, emission and combustion characteristics of kirloskar TVI DI diesel engine using diesel-ethanol-surfactant as fuel

R. Parthasarathi, S. Gowri and C. G Saravanan

Abstract:

An experimental investigation is carried out to analyze the effect of different diesel-ethanol blended fuels on the engine performance, combustion and emissions, such as Brake specific fuel consumption, Brake thermal efficiency cylinder pressure, Heat release rate, oxides of nitrogen, hydrocarbon and smoke density. The experiments were conducted on a single cylinder four stroke water-cooled naturally aspirated open chamber (DI) Kirloskar TVI diesel engine fuelled with neat diesel and diesel-ethanol-Tween80 (Surfactant) blends at an injection pressure of 220 kgf/cm² with constant speed of 1500 rpm at varying load condition. The results indicate that the emulsified fuel decrease the specific fuel consumption and increase the brake thermal efficiency. This is due lower heating value of blended fuel. Among the blends the D50 E40 concentrations shows the highest oxides of nitrogen, Hydrocarbon and lowest smoke density were obtained at maximum brake power of the engine. The cylinder pressure and heat release rate are higher and recorded as 76 bar and 152 kJ/m³deg for D50 E40 blends than other blends and neat diesel fuel.

Meti-lis model to estimate H2s emission rates from to lich river, Vietnam

Nguyen Huu Huan, Nguyen Xuan Hai, Tran Yem and Nguyen Nhan Tuan

Abstract:

This paper assessed the water quality in To Lich River through contaminated indicators such as DO, COD, and BOD₅. The emission of H₂S from the river water had impacted the ambient air quality in the riparian areas of To Lich River in Hoang Liet Ward, Hoang Mai District, Ha Noi City. The measured concentration of H₂S in ambient air in the riparian area varied within the range of 48.7 ± 23.1μg/m³. The H₂S emissions rate from wastewater in the To Lich River was estimated about 2, 828.0 mg/m/h. METI-LIS model can be applied to forecast H₂S emission rate from To Lich River. The predicted results showed the close relationship with the measured values by correlation coefficient R² = 0.9197.

Abstract:

This paper presents field programmable gate array (FPGA) implementation of the forward/inverse discrete wavelet transform for denoising Fiber Optic Gyroscope (FOG) signal. In this work an extensive study on the effect of different threshold techniques of DWT algorithm are carried out denoising the FOG signal. Different architectures such as multiply and accumulate (MAC), Distributed Arithmetic (DA) and Systolic MAC are used to implemented the DWT algorithm on XILINX Virtex-5FXT-1136 FPGA development board. The resource utilization of all the three architectures are compared and the experimental result concludes that the DA architecture is the optimum architecture that gives latency of 1057 clock cycles for processing 1024 samples with maximum operating frequency as 174 MHz. Further the DWT algorithm reduces the drift by 5 and 100 times for denoising the gyroscope and accelerometer signal of the considered FOG. These results confirmed a DWT shows good improvement of denoising for processing the noisy FOG and accelerometer signal.

Abstract:

In this paper is present a functional model as very important for the economic evaluation study in the deposits of carbonate rocks. One such model is applied to mineral deposit limestone “Kosmaç" which uses the company Doni Fert. So for a fair assessment of investment in technology to acquire a cubic meter of useful minerals, should question Benefit/Cost Analyses (B/C) for these mineral resources in Kosovo.

Experimental study on emission and performance analysis of non edible rice bran oil as an alternative fuel for direct injection diesel engine

Prasad Baburao Rampure, C Venkataramana Reddy and K Vijayakumar Reddy

Abstract:

The financial growth of the country is measured by efficient use of natural resources especially fuel. Fossil fuels have played a dominant role in the rapid industrialization of the world and thereby increased and improved quality of life. However, due to the threat of supply crunch ever rising prices and the effect of green house gases caused by conventional fuels there is an urgent need to explore the possibility of using straight vegetable oils (unmodified) as alternative fuels to reduce the pollution and to increase the energy self-reliance of the country, especially in rural areas. The study aims to investigate experimentally the performance analysis of non-edible rice bran oil, a straight vegetable oil [SVO] and its blends with diesel as fuel and also to investigate the exhaust emission characteristics in the single cylinder, direct injection, four stroke diesel engines typically used in Indian agricultural sector. Experiments were conducted by using the blends of diesel with non-edible rice bran oil in various proportions from ten to one hundred percentages by volume and at varying engine loads. Studies have found that the use of blends of more viscous non-edible rice bran oil and diesel in various percentages result in the decrease in the NO_X emission  while the brake thermal efficiency reduces marginally.

SAR reduction in slotted PIFA for mobile handsets using RF shield

T. Anita Jones Mary and C. S Ravichandran

Abstract:

This paper proposes a multiband handset antenna combining PIFA and novel slots on a radiating patch of PIFA for mobile applications. Two slots were introduced in order to embody 900 and 1800 MHz band. Radiation patterns are computed in free space as well as in the presence of the head.  Specific Absorption Rate (SAR) of the slotted PIFA antenna is calculated and is compared with the SAR limits in the safety standards. SAR is investigated, by discussing the effect of RF shield which is introduced between the slotted PIFA antenna and head. Simulation results show that with the introduction of the RF shield of thickness of 1mm, SAR reduces by 12%. All simulations are done in FEKO software.

Rainfall intensity variation for observed data and derived data - a case study of Imphal

Zameer Ahmed, D Rammohan Rao, K. Ram Mohan Reddy and Ellam Raj

Abstract:

For estimation of runoff especially for urban areas short duration rainfalls are necessary. However especially in developing countries like India availability of short duration rainfalls is scarce and data available is mostly for daily rainfall data. In such cases determination of design rainfall is becoming an approximation and thus leading to frequent failure of drainage network and subsequent floods. In the absence of short duration rainfall data, data is generated for short durations like 1hr, 2hr, 3-hr, 6-hr and 12-hr rainfall values were obtained using an Indian Meteorological Department (IMD) empirical reduction formula is used in the absence of observed data (t-hour rainfall). Frequency analysis was then carried out to establish Intensity-Duration-Frequency (IDF) relationships. In the present study an attempt has made to find the difference of intensity of rainfalls obtained from observed data and derived data by taking Imphal rainfall data which is available for 15 min time interval.

Maintenance management for public infrastructure for Malaysian local authorities

Hamimah Adnan, Zafrul Fazry Mohd Fauzi, Ismail Rahmat and Azizan Supardi

Abstract:

Proper and timely maintenance and rehabilitation of facilities is essential for safe operations and the overall economics. Decisions as to what, where, when, and how maintenance and rehabilitation should be performed need to be made. These decisions must consider condition, but budget constraints and other tangible and intangible issues also affect the decision-making process. However, this public satisfaction level is unachieved due to lack of proper facilities management and lack of awareness among the local authorities’ staffs in Malaysia. This research investigates current implementation in maintenance management and to make recommendations to improve infrastructure maintenance management in Malaysian local authorities Through the interviews and questionnaires that are directly being conducted with the maintenance personnel give a clearer picture on the problems arise by the maintenance personnel in local authorities during carrying out their infrastructure maintenance work. Approach used by most of the local authorities in taking action on the maintenance of infrastructure works are almost the same except their different ways of selecting or appointing the contractors are a bit different. Views from the maintenance personnel regarding the obstacles arise in carrying the maintenance works has to be address correctly, so that the maintenance works for the infrastructure facilities are to be carried out effectively.

Abstract:

The present study focused on the production of alkali activated flyash lightweight aggregate by means of pelletization. The basic physical properties and mechanical characteristics of lightweight aggregate produced were analyzed systematically. Factors affecting the efficiency of pelletization process such as type of binder, moisture content, process duration and alkali content were evaluated. Further, characterization of aggregates was evaluated based on the specific gravity, gradation, density and aggregate crushing strength. It was observed from the test results that the pelletization efficiency of different aggregates was found to be maximum when the angle of pelletizer is set to 36º with an optimized speed of 55 rpm. Also, compared to other types of pelletized flyash aggregates, the aggregates containing flyash mixed with 20% cement and 12M NaOH exhibited a higher crushing strength of 13.72 MPa with minimum water absorption of 18.33%. With the optimum addition of water upto 31% during pelletization, the efficiency and strength of aggregates were found to be increased. In addition, the optimum pelletization duration (15 to 20 minutes) resulted in higher compaction energy with uniform size of aggregates. Also, the addition of alkali (NaOH) to flyash aggregates showed higher strength gain within shorter curing period in hot air oven.