Trepça ore belt and lead and zinc distribution in Badovc mineral deposit, Kosovo (SE Europe)

S. M. Hyseni, B. N. Durmishaj, B. L. Fetahaj and D. Large

The Trepça Belt of Pb-Zn-Ag mineralization is located the NNW-SSE trending Vardar zone. The Belt extends for ever 80 km, and supported five mines during period 1930-2010, and contains a number of the other Pb-Zn occurrences. The replacement and vein type mineralization is hosted primarily by Mesozoic carbonates, but also occasionally by amphibolites, and it display a clear structural control. Mineralization is spatially and genetically related to Neogene andesite-dacite extrusive and sub volcanic intrusive. We use for this paper only Badovc mine. In this paper we featured lateral distribution and inside ore bodies of Pb and Zn how two main components and Ag association with economic importance in the mineral deposit Badovc. Pb and Zn distribution within the contoured ore body in Badovc is heterogeneous. Lateral Pb, Zn and Zn/Pb ratio distributions are studied for the ore bodies 6, 7 etc. of Badovc ore deposit. Mineral deposit of Badovc, consisting of Pb- Zn- Ag mineralization, does not close genetically towards its deepest exploitation level.

A spectral-neuro modeling for fault location and diagnosis in distributed power system

P. Chandra Sekhar, B. V. Sanker Ram and K. S. Sarma

In this paper an approach for the improvement of the neural training error and its improvement for real time system is developed. The approach of learning the neural network is developed using the advanced feature of wavelet transformation approaches and is designed to observe even the minor current variations, which result in variation in the observation result. In this paper a contribution towards the accurate estimation of the current disturbance is developed using DWT learning for a neuro classifier.

A new multiband patch microstrip plusses fractal antenna for wireless applications

Fawwaz J. Jibrael and Mahir H. Hammed

A new compact Plusses fractal patch microstrip antenna is investigated to be an efficient scheme of miniaturization based on the simulation results. The proposed antenna has shown to possess an excellent size reduction possibility with good radiation performance for wireless applications. The new designed antenna has an operating frequency of 2.471 GHz, 7.032 GHz, 8.651 GHz and 11.86 GHz, with acceptable bandwidth and S₁₁< -10 dB (VSWR<2). The radiation characteristics, VSWR, and S₁₁ of the proposed antenna are described and simulated using microwave office
MWO 2007 v7.5.

Application of BJT as a bidirectional switch for low voltage circuit protection

G. R. Padmini, M. Satyam, K. Lalkishore and P. A. Govindacharyulu

In this paper the function of an all electronic circuit breaker has been demonstrated. Till recently the alternatives to electromechanical and magnetic circuit breakers are very few. Solid state devices are reliable and have high life time. This circuit breaker is demonstrated with BJT as a bidirectional switch. The operation of the bidirectional switch is analyzed for different operating conditions to determine the limitations of this design. Bidirectional switches with TRIAC, IGBT are commercially available however circuit breaker with BJT as a bidirectional switch is a new approach for low voltage circuit protection.

Performance modeling of infinitely wide exponentially shaped slider bearing lubricated with couple stress fluids

Oladeinde M. H. and Edokpia R. O.

Abstract:

In this paper, the pressure distribution and load capacity of an infinitely wide exponentially shaped slider bearing lubricated with a non Newtonian couple stress fluid is presented. Based on Stokes micro continuum theory, the effect of couple stresses on the pressure distribution and load are computed using continuous Galerkin finite element method The domain is discretized into uniform mesh of quadratic isoparametric elements and Gauss quadrature used to numerically integrate the stiffness integrals to obtain stiffness matrices for all elements which are subsequently assembled   to form the global system of equations. The resulting global matrix is solved using Gauss Seidel iterative scheme. The numerical method adopted for the solution is shown to produce convergent results when implemented on a sequence of successively finer meshes. Having established the reliability of the numerical method, parametric studies are carried out to show the effects of couple stresses and aspect ratio on the pressure distribution and load. Computations put forward show that the effect of couple stresses is to enhance the load carrying capacity of the bearing. It has also been shown that compared to the Newtonian case, the pressure developed in the clearance zone of the bearing is augmented.

Rainfall evaluation of root water-uptake induced deformation

M. A. Mu’azu, N. Ali and K. Ahmed

Abstract:

A volume change was modeled as a result of matric suction change caused by vegetative induced moisture migration. Tree root water-uptake increases soil strength by increasing the soil matric suction and as well causes volume change which might be detrimental to geotechnical structure. Rainfall effects are evaluated for full cycle are simulated for periods that covers a spring/summer soil-drying phase of 6 months followed by an autumn/winter 6 month recharge phase. The effects of with and without rainfall has been incorporated into the simulation work. Generally rainfall reduces the amount of the root generated matric suction and ground movement due to recharge. From the results, vegetative induced matric suction change, induced deformation without considering rainfall effect tends to be too conservative and work of this kind is not complete without inclusion of rainfall data.

A third order Euler method for numerical solution of ordinary differential equations

Moses A. Akanbi

There has been a great deal of interest to improve on Euler methods for solving Initial value Problems (IVPs) in Ordinary Differential Equations, because of its easy implementation and low computational cost. In this work, we continue in the spirit of Euler, to develop a new third order Euler Method. The new scheme was implemented on some standard IVPs. Our computational results show that the method is consistent, accurate and convergent of order 3. Succinct overviews of its basic properties necessary for the selection of a good numerical method in the development of program codes are also presented.

Performance evaluation of stabilized flyash subbases

M. Anjan Kumar, D. S. V. Prasad and G. V. R. Prasada Raju

Abstract:

Expansive clay is a major source of heave induced structural agony. Swelling of expansive soils causes serious problems and produces harm to many structures. Many research organizations are doing extensive work on waste materials concerning the viability and environmental suitability. Flyash, a waste derivative from coal burning in thermal power stations is plentiful in India causing severe health, environmental and dumping problems. Attempts are made to investigate the stabilization process with model test tracks over expansive/sand subgrade in flexible pavements. Cyclic plate load tests along with heave measurements are carried out on the tracks with chemicals like lime and lime-cement introduced in flyash subbase laid on sand and expansive subgrades. Scanning electron micrographs are obtained for different samples collected at a depth of 0.2m from the test stretches. The study revealed that lime - cement combination could be the potential alternative compared to the other treatments tried in the investigation.

Resonance fields and shielding of a living room exposed to radiations from a transmitter by vectorial finite element- neural network method

M. S. Al Salameh and R. S. M. Daraghmeh 

Abstract:

This paper presents the application of vectorial finite element-neural network method along with automatic rectangular mesh generation for the prediction of the resonance fields in two dimensional model of concrete room. This field may come from an electromagnetic transmitter such as two-way radio transmitter, amateur radio transmitters, or paging transmitters. The influence of placing a conductive window screen is studied. The electric field is calculated inside the room with various situations: room with door and window, with two windows and furniture, with door and window in addition to furniture, and with a fine metallic window screen. The shielding effectiveness of the window screen is evaluated for different incident angles of the wave. It is found that window screen can provide about 30 dB shielding effectiveness.

A modified fullcycle discrete Fourier algorithm based digital multifunction relay for transmission line protection

P. Suresh Babu and S. V. Jayaram Kumar

Abstract:

Since it is not possible to optimize a standard relaying system to every protection need, Digital Multifunction protection systems are proposed as they  have features like cost efficiency, functional flexibility, adaptive relaying and self checking capability. With the advantage of generally available hardware and software, having the speed and capability of digital relays necessary for protection application, it has now become possible for the relay engineers to develop and implement custom protection solutions for those applications where standard packages may not provide the necessary flexibility or performance. A modified Fullcycle Discrete Fourier Transform (FCDFT) Algorithm based digital multifunction relay is proposed which has capability of executing trip command by extracting exact fundamental frequency component, by eliminating harmonics and decaying DC offset component, during faults in power systems. The proposed algorithm was tested for different faults on 220KV, 100km overhead transmission line. Electromagnetic Transient Program (EMTP) and Power System Computer Aided Design (PSCAD) were used to generate waveforms under different fault locations and fault inception angles. The results show that the proposed Digital multi-function relay worked efficiently and reliably.

Energy attenuation capability of woven natural silk/epoxy composite plates subjected to drop-weight impacts

Albert Uchenna Ude, Kamauzzaman Sopian, Ahmad Kamal Ariffinand and Che Husna Azhari

Abstract:

The impact energy attenuation and damage characteristics of woven natural silk (WNS)/Epoxy laminated composite panels were evaluated. The Samples prepared in configurations of sandwich WNS/Epoxy/Honeycomb, WNS/Epoxy/Coremat, WNS/Epoxy/Foam and reinforced WNS/Epoxy (reference sample) laminate panels were subjected to low velocity impact loading at energy levels of 32J, 48J and 64J respectively. Impact parameters like load–deflection, load–time and absorbed energy-time behaviour were measured for evaluating the impact performance in terms of load bearing capabilities, energy absorption and failure modes. Evaluation of the results showed that WNS/Epoxy/Coremat displays better load bearing capability qualities compared to the other three samples. In general energy absorption decreases as impact energy increases in all composite samples; WNS/Epoxy/Foam was seen as better energy absorber. Damage areas increased with increasing energy while time to response decreased in all configurations. SEM micrographs show mode of failure as matrix crack, delamination and fibre breakage.

Customer outage cost evaluation in electric power systems

J. Manikya Rao, P. V. N. Prasad and G. Tulasi Ram Das

Abstract:

In order to relate investment costs to the resulting levels of supply reliability, it is required to quantify supply reliability in a monetary basis which can be achieved by calculating the expected interruption costs (EIC). Customer interruption costs (CIC) are used as substitute in the assessment of reliability worth in electric power systems. In order to determine an optimal and reliable level of customer service, reliability cost/worth is to be assessed by calculating the costs associated with different system configurations and assessing the corresponding reliability worth at the respective system load points. This paper presents the utilization of a practical radial distribution system of APCPDCL /APTRANSCO database in the development of individual sector and customer damage functions. Customer interruption costs due to failure in electrical energy supply depend on many factors. A composite customer damage function is created for combinations of all customer classes. The main objective of the paper is to assess reliability cost /worth indices of expected energy not supplied (EENS), expected cost of interruptions (ECOST) and interrupted energy assessment rate (IEAR) of a typical radial practical distribution system using a generalized analytical technique. The effects on customer interruption cost indices associated with alternate supply, protection devices, different switch fuse, and breaker are included in the analysis and also compared with the results of reinforcement of system by disconnect switch additions. The results presented in this paper will be useful for the electric power utilities, designers and planners in the decision-making stage.