Evaluation of shear resistance of high strength concrete beams without web reinforcement using ANSYS

Sudheer Reddy L., Ramana Rao N. V. and Gunneswara Rao T. D.

The paper attempts to predict the shear strength of high strength concrete beams (70 Mpa) with different shear span to depth ratios (a/d = 1, 2, 3 and 4) without web reinforcement. The reinforced concrete beams are tested under shear loading and are modeled in ‘ANSYS’, which is Finite Element Analysis software. The test results are compared with the ‘ANSYS’ model results. The shear capacity evaluated using ‘ANSYS’ model for the beams are closer to test results. Thus a simplified equation has been evaluated using the previous database and the ANSYS model, to predict the shear capacity of high strength concrete beams without shear reinforcement.

New hybrid filtering techniques for removal of Gaussian noise from medical images

Gnanambal Ilango and R. Marudhachalam

The most significant feature of diagnostic medical images is to reduce Gaussian noise which is commonly found in medical images and make better image quality. In recent years, technological development has significantly improved analyzing medical imaging. This paper proposes different hybrid filtering techniques for the removal of Gaussian noise, from brain tumor medical images, by topological approach. The filters are treated in terms of a finite set of certain estimation and neighborhood building operations. A set of such operations is suggested on the base of the analysis of a wide variety of nonlinear filters described in the literature. The quality of the enhanced images is measured by the statistical quantity measures: Root Mean Square Error (RMSE) and Peak Signal-to-Noise Ratio (PSNR).

Numerical analysis with finite and boundary elements of thermal fields in steady state regime

Ioan Sârbu and Oana Popina

Solving the differential equation of heat conduction the temperature in each point of the body can be determined. However, in the case of bodies with boundary surface of sophisticated geometry no analytical method can be used. In this case the use of numerical methods becomes necessary. The finite element method is based on the integral equation of the heat conduction. This is obtained from the differential equation using variational calculus. The temperature values will be calculated on the finite elements. Then, based on these partial solutions, the solution for the entire volume will be determined. Using this method we can divide into elements also fields with any border. Also, numerical modelling with boundary elements is used for analysis of heat conduction. In this paper are developed basic ideas of numerical analysis with finite elements and boundary (constant) elements of conductive thermal fields generated or induced into solid body in steady state regime. The temperature distribution in some solid bodies and in pipe insulation is analyzed using analytical method and finite element and boundary element methods, implemented in two computer programs developed by the author. This shows the good performance of the proposed numerical models.

A two species commensalism model with limited resources- A numerical approach

N. Phani Kumar, B. Ravindra Reddy and N. Ch. Pattabhi Ramacharyulu

In this paper a mathematical model of commensalism between two species (S₁ and S₂) with limited resources is investigated. The commensal species (S₁), in spite of the limitation of its natural resources flourishes drawing strength from the host species (S₂). This model is characterized by a pair of first order non-linear coupled differential equations. All the four equilibrium points of the model are identified and the criteria for the stability are discussed. The non-lin ear coupled system-equations are solved numerically by employing fourth order Runge-Kutta method and the results are presented. Further, some threshold results are stated.

Steady state motion of rail vehicle with controlled creep forces on curved track

M. Messouci

Abstract:

A linear analysis of steady state curve traversing is developed for rail vehicle with wheels coupled with a torsional viscous damper. The governing equations are given and are solved numerically. We consider the equilibrium of the bogie with two wheel sets acted upon by the forces of gravity and the transverse force. The approach is based on providing guidance by creep forces in conjunction with wheel conicity, so that flange contact is normally avoided. It describes the behavior of the vehicle in the curves of different radii. It is therefore important to define the characteristics of the torsional damper. It gives the modulus (magnitude) of the moment of friction in the dampers produced by the relative motion of the wheels as well as the bogie yaw, the relative lateral and yaw displacement of the leading and trailing wheel set at each curve track of constant curvature.

Darcy scale NAPL dissolution in heterogeneous stratified porous media

B. Mabiala, C. Tathy and D. Nganga

Abstract:

The aim of this study is to develop NAPL dissolution in heterogeneous porous media by one and two dimensional physical model at macroscopic Darcy scale. The model describes the movement of a water phase in the presence of a trapped polluting phase at residual saturation. Two limit cases of dissolution were studied: local equilibrium case and the local non equilibrium case. The construction uses the finite volume methods for the approximation of equations. The numerical tests emphasize particularly the evolution of the zone of exchange between the organic and water phases. Local non equilibrium situations obtained following the mechanisms hereafter, heterogeneity effects of the medium and heterogeneity effects of the initial saturations induced by hydrodynamic instabilities or particular conditions of installation, were characterized.

Experimental study of temperature stratification in a thermal storage tank in the static mode for different aspect ratios

Abdul Jabbar N. Khalifa, Ayad T. Mustafa and Farhan A. Khammas

Thermal stratified storage tanks are an effective method to improve the efficiency of thermal storage devices that are commonly used in thermal systems when the available energy source is irregular or when a time lag exists between the production and the demand. It has been shown that thermal stratification is affected by a number of factors such as mixing due to the inlet and outlet streams, heat losses to the environment and tank configuration such as the aspect (height to diameter) ratio. Thermal behavior and stratification of hot water storage tanks during the stagnation mode is investigated experimentally in this study for three different aspect ratios (AR) of the tank, namely 2, 1 and ½. The study addresses the change in water stratification during the cool down of the water inside the storage tank of thermal systems in the 85^oC to 30^oC temperature range, which lies within the operating range of most conventional and solar hot water and liquid based heating systems.

A study of process parameters of friction stir welded AA 6061 aluminum alloy in O and T6 conditions

Indira Rani M., Marpu R. N. and A. C. S. Kumar

Abstract:

Friction Stir Welding (FSW) is fairly a recent technique that uses a non consumable rotating welding tool to generate frictional heat and plastic deformation at the welding location while the material is in solid state. The principal advantages are low distortion, absence of melt related defects and high joint strength. Tool design and material plays a vital role in addition to the important parameters like tool rotational speed, welding speed and axial force. The paper focuses on optimization of FSW parameters in different conditions of base material and the microstructures of the as-welded condition are compared with the post weld heat treated microstructures welded in annealed and T6 condition.

Petri net to ladder logic diagram converter and a batch process simulation

Abstract:

Discrete-event dynamic systems (DEDS) are characterized by a set of states which the system can take, and by the set of asynchronous events that cause the state changes at discrete time points. Programmable logic controllers (PLCs) are still important special purpose computers used to automate the DEDS in industry. Ladder logic diagrams (LLDs) are still the most popular graphical programming tools of the PLCs; but the major problem is that programming is done heuristically and the LLDs are difficult to be used for both analysis and performance evaluation. Petri nets (PNs) are nowadays the most effective modeling environment for both the design and implementation of DEDS. This paper proposes a PN to LLD conversion tool, used for graphical editing of a PN net model of a DEDS controller and for converting this PN into the equivalent LLD for programming a PLC. The conversion algorithm is presented, considering many types of transitions, places, and arcs with generality that many types of PNs can be considered. This paper also presents a simulation of a batch process, on a personal computer from one side, interfaced with a real PLC from the other side, that is programmed using a LLD obtained from the conversion of a suitable PN model using the proposed conversion tool. Compared with a LDD got heuristically, the LLD got from a PN conversion is simpler, understandable, and meeting all the characteristics obtained from the PN analysis.

Decision support system for transport demand management: Object oriented approach using kappa pc 2.4 expert system shell

Resdiansyah Mansyur, Riza Atiq O. K. Rahmat, Amiruddin Ismail and Mohamad Raduan Kabit

Abstract:

In view of the fact that supply strategies alone could not solve urban congestion, many cities around the globe have adopted Transport Demand Management (TDM) strategies as part and partial of their congestion mitigation plan. TDM comprises several strategies and policies that aim to modifying travelers’ behaviour. TDM comprises strategies and policies that are different in nature which can be divided into several categories according to how they affect travelers’ behavior. Selecting and determining suitable TDM strategies for a particular congestion mitigation goal can be a complex task; thus requires expertise. In this regards, the effectiveness of a TDM strategy is primarily depending on whether its selection was appropriately examined prior to its field implementation. This paper presents the development of an expert system shell for TDM. The process of organizing the available knowledge of TDM strategies, as well as the process leading to the selection of one or more strategy advice, is encoded in the knowledge based expert system shell developed for the purpose by using shell expert system Kappa-PC version 2.4 which was adopted object oriented approach and high resolution graphical user interface. The advice given from the working system was evaluated and validated by comparing the output of the system against the recommendations made by transportation professionals. The evaluations indicate favourable results for the system. The expert advisory system can be used as a decision support system as well as a teaching tool for junior transportation engineers, planners, private developers, and government officials.

On utilization of wind energy potential in Nigeria

M. S. Adaramola

Abstract:

The aim of this paper is to review wind energy availability in Nigeria and discuss the potential of using this resource for generation of wind power in the country. The power output from a wind turbine is strongly depend on the wind speed and accurate information about the wind data in a targeted location for wind turbine is essential. The wind speeds in Nigeria range from about 2 to 9.5 m/s based on recent reported data and the trend show that wind speeds are low in the south and gradually increases to relatively high speeds in the north. The areas that are suitable for exploitation of wind energy for electricity generation as well as for water pumping were identified. Also some of the challenges facing the development of wind energy and suggested solutions were presented.

Allocation of FACTS devices for ATC enhancement using genetic algorithm

K. Radha Rani, J. Amarnath and S. Kamakshaiah

Abstract:

In this paper, a method using Genetic Algorithm is proposed to determine the optimal allocation of FACTS devices for maximizing the Available Transfer Capability (ATC) of power transactions between source and sink areas in the deregulated power system. Two types of FACTS are simulated in this study namely Thyristor Controlled Series Compensator (TCSC) and Unified Power Flow Controller (UPFC) for enhancing the available transfer capability of the interconnected power system. A Repeated Power Flow with FACTS devices including ATC is used to evaluate the feasible ATC value within real and reactive power generation limits, line thermal limits and voltage limits. An IEEE24- bus (single area) system is used to demonstrate the effectiveness of the algorithm as an optimization tool to enhance ATC. A Genetic Algorithm technique is used for validation purposes. The results clearly indicate that the introduction of FACTS devices in a right location could enhance ATC.

Performance and combustion characteristics of a typical motor bike engine operated on blends of CNG and hydrogen using electronically controlled solenoid actuated injection system

S. S. Sandhu, M. K. G. Babu and L. M. Das

Abstract:

This paper discusses the development of an electronically controlled gas injection system for hydrogen supplemented single cylinder Enfield engine. In view of its typical combustion characteristics, the fuel induction technique plays a very dominant and sensitive role in the performance as well as the combustion characteristics of hydrogen supplemented CNG engine. The designed system should have adequate flexibility to provide the appropriate mixture into the engine at the appropriate point in the engine cycle operation. The motor bike engine was fuelled with neat CNG and mixtures of hydrogen in natural gas (HCNG) of 5, 10, 15 and 20% by energy. The designed Electronic Fuel Injection System ensured successful operation of engine running on different fuel blends over a wide range of load and speed without causing any undesirable combustion phenomena such as backfire or pre-ignition. The performance and combustion characteristics were determined under various operating conditions.

Conceptual design of an amphibious vehicle: VECTOR

Bart Sitek and Wei Yang

Abstract:

This work is to present conceptual design of an amphibious vehicle named “VECTOR” that has great high-speed and long range capabilities. The vehicle is designed to carry up to 50+ personnel or 14 tons of payloads in a range of 1800 km at nominal speed of 360 km/h. The VECTOR not only possesses pros of current helicopter technology, that is, efficient vertical flight and hover capability, but also is capable to take-off/land on water, land, grass, and other relatively flat surfaces. It also introduces a brand new concept of fuselage and chassis design. Tiltrotor continues to be the best candidate for diverse field and rescue operations. All the important aspects, including material, power, propulsion systems, aerodynamics and stability are thoroughly studied and analyzed in the following paper. Capabilities of the VECTOR can fulfill the ever-expanding civil requirements and contribute to the current search and rescue teams in any part of the world.