Showing papers in "American Journal of Engineering and Applied Sciences in 2009"

Supply Chain Performance Evaluation: Trends and Challenges

Abstract: Problem statement: In today’s manufacturing world, globalization policies and rejuvenation have created a more intensive competition amongst manufacturers. On the other hand, manufacturers have turned to the option of adopting innovative technologies, process re-engineering and strategies such as efficient supply chain management to achieve a sustainable competitive advantage. Effective supply chain performance measurement has been identified as a key issue towards efficient supply chain management. To explore the extent of research in supply chain performance measurement and establish the gap in knowledge in supply chain performance measurement using fuzzy logic operation. Approach: Literatures in the area of supply chain performance measurement had been extensively reviewed. Both traditional and fuzzy logic approaches to supply chain performance measurement were scrutinized. Further scrutiny was carried out to establish potential research areas in the application of fuzzy logic operations in supply chain performance measurement. Results: The supply chain performance measurement using fuzzy logic operation was identified as a new direction in measuring the uncertainty and ambiguity surrounding supply chain performance measurement. Direction for further studies in the application of fuzzy logic operation in supply chain management and its performance measurement were also identified. Conclusion: Result of this study implied that there is still a gap in knowledge in the area of supply chain performance measurement. This new direction of studies involved extending the existing supply chains to incorporate product recovery after the useful life.

Experimental investigation on geomechanical properties of tropical organic soils and peat

Abstract: Problem statement: Organic soils and peat were believed to be geotechnically problematic due to their very high compressibility, very low shear strength and difficult accessibility. Although conventional soil mechanics theory could be applied to the soils, it was found that important anomalies existed which required special considerations. Correlations between geomechanical parameters for the soils were known to be important for geotechnical engineers to be able to obtain suitable design parameters, as well as to find suitable construction techniques on these soft materials. Approach: To evaluate the geomechanical characteristics of the soils, field and laboratory investigations were carried out according to the organic contents. To achieve such purpose, the soils samples having different organic contents from several locations in Malaysia were collected to determine the correlations of various geomechanical properties of the soils. The classifying tests were determined based on the test procedures according to the British Standard Institution. The compressibility behavior of the soils was determined by Rowe cell consolidation test. Results: The test results indicated that the natural water contents, organic contents, liquid limits, specific gravities and bulk densities ranged from 150-700%, 50-95%, 180-500%, 1.05-1.9 and 0.8-1.2 Mgm-3, respectively. The compression indexes of the soils were higher than Hobbs and Skempton’s approximations. Conclusion/Recommendations: The soils properties were highly dependent on the organic contents. With an increase in organic content, the natural water content, liquid limit, compression index and void ratio increased and the specific gravity and bulk density decreased. Furthermore, the hemic and sapric peat had lower shear strength than the fibrous peat. The first-of-its-kind study was the first step on the road to persuade researchers to improve these problematic soils.

Hot Machining of Hardened Steels with Coated Carbide Inserts

Abstract: Problem statement: The benefits of easier manufacture of hardened steel components can be substantial in terms of reduced machining costs and lead times compared to the traditional route involving machining of the annealed state followed by heat treatment, grinding/EDM and manual finishing. But machinability of hard material through conventional machining is hindered due to excessive wear of the cutting tools and differently in achieving desired quality of the machined surface. In end milling the cutting tool is not in constant operation and so undergoes a heat cycle during the intermittent cutting. This alternate heating and cooling of the inserts lead to the thermal cracks and subsequently failure of the tool. Approach: This study was conducted to investigate the effect of preheating through inductive heating mechanism in end milling (vertical milling center) of AISI D2 hardened steel (56-62 HRC) by using coated carbide tool inserts. Apart from preheating, two other machining parameters such as cutting speed and feed were varied while the depth of cut was kept constant. Results: Tool wear phenomenon and machined surface finish were found to be significantly affected by preheating temperature and other two variables. Preheating temperature of 335°C coupled with cutting speed of 40 m min-1, depth of cut of 1.0 mm and feed of 0.02 mm/tooth resulted in a noticeable reduction in tool wear rate leading to a maximum tool life 188.55 min. In addition, cutting speed of 56.57 m min-1 together with feed of 0.044 mm/tooth and depth of cut 1.0 mm at which maximum VMR (9500 mm3) was secured provides a better surface finish with minimum surface roughness 0.25 μm leaving a possibility of skipping the grinding and polishing operations for certain applications. Conclusion/Recommendation: Through the end milling of preheated AISI D2 hardened steel by using TiAlN coated carbide cutting tool it can be concluded that an overall enhanced machinability is achievable by preventing catastrophic damage of the cutting tool at higher levels of feed and cutting speed.

Effect of Microwave and Ultrasonic Pretreatments on Biogas Production from Anaerobic Digestion of Palm Oil Mill Effleunt

Abstract: Problem Statement: Oil palm production is a major agricultural industry in Malaysia. In 2006, palm oil mills in Malaysia produced more than 58 million tonnes of Palm Oil Mill Effluent (POME). Existing treatment in a series of open lagoons at high ambient temperatures, results in the uncontrolled production of methane and carbon dioxide, which are both green house gases (GHGs). With the increased worldwide concern on environmentally friendly production processes particularly the emission of methane, it is important to develop an alternative concept for POME treatment. This study elucidates the effects of pre-treatment of palm oil mill effluent by microwave irradiation and ultrasonic on anaerobic digestion. Approach: Effects of pre-treatment on sludge characterisation parameters were monitored. The Soluble Chemical Oxygen Demand (SCOD)/total COD ratio and biodegradability of soluble organic matter increased significantly after both the pre-treatments which indicated an increase in disintegration of the floc structure of the sludge. Three identical bioreactors with working volume of 5 litres were used as anaerobic digesters at 32-35°C. The reactors were separately fed with pre-treated sludge (microwave, ultrasonic and combination of microwave and ultrasonic) and control sludge at different Hydraulic Retention Times (HRT) to check for the production of methane. Results: The maximum SCOD/TCOD ratio reached almost 29% after 30 min of ultrasonic treatment, while it was 45% after 7 min of microwave irradiation. The BOD5/SCOD ratio also increased after the pre-treatments suggesting the biodegradability of the soluble organic material increased during the treatment. It was observed that TVFA released was increased after both the treatments, with microwave treatment showing a higher yield of TVFA. Greatest enhancement in methane production was shown by the 3 min microwave plus 10 min ultrasonic treatment. Conclusion: The microwave in combination with ultrasonic would be a rapid and economical method for sludge pre-treatment for enhancement of biogas production.

Femtotechnology: Nuclear Matter with Fantastic Properties

Abstract: Problem statement: At present the term 'nanotechnology' is well known-in its' ideal form, the flawless and completely controlled design of conventional molecular matter from molecules or atoms. Such a power over nature would offer routine achievement of remarkable properties in conventional matter and creation of metamaterials where the structure not the composition brings forth new powers of matter. But even this yet unachieved goal is not the end of material science possibilities. The author herein offers the idea of design of new forms of nuclear matter from nucleons (neutrons, protons), electrons and other nuclear particles. Approach: The researcher researches the nuclear forces. He shows these force may be used for design the new nuclear matter from protons, neutrons, electrons and other nuclear particles. Results: Author shows this new 'AB-Matter' has extraordinary properties (for example, tensile strength, stiffness, hardness, critical temperature, superconductivity, supertransparency and zero friction.), which are up to millions of times better than corresponding properties of conventional molecular matter. He shows concepts of design for aircraft, ships, transportation, thermonuclear reactors, constructions and so on from nuclear matter. These vehicles will have unbelievable possibilities (e.g., invisibility, ghost-like penetration through any walls and armor, protection from nuclear bomb explosions and any radiation flux). Conclusion: People may think this fantasy. But fifteen years ago most people and many scientists thought-nanotechnology is fantasy. Now many groups and industrial labs, even startups, spend hundreds of millions of dollars for development of nanotechnological-range products (precise chemistry, patterned atoms, catalysts and meta-materials) and we have nanotubes (a new material which does not exist in Nature!) and other achievements beginning to come out of the pipeline in prospect. Nanotubes are stronger than steel by a hundred times-surely an amazement to a 19th Century observer if he could behold them. Nanotechnology, in near term prospect, operates with objects (molecules and atoms) having the size in nanometer (10-9 m). The researcher here outlines perhaps more distant operations with objects (nuclei) having size in the femtometer range, (10-15m, millions of times less smaller than the nanometer scale). The name of this new technology is femtotechnology.

Optical Nonlinear Proreties and Optical Limiting Effect of Metanil Yellow

Abstract: Problem statement: The third order nonlinear optical properties of organic polymers are used in high speed telecommunication, optical limiters and optical computers. The purpose of the study was to determine the third order nonlinear characteristics and optical limiting effect of the organic dye, metanil yellow in liquid and solid medium. Approach: The samples were prepared by dissolving the dye in acetonitrile (liquid medium) at different concentration and thin film was prepared by bulk polymerization method. The nonlinear optical responses of the samples were studied by using single-beam Z-scan technique. The optical limiting effects of the samples were studied by using a CW, Nd: YAG laser at 532 nm. Results: The open aperture Z-scan of the solution and solid samples displayed reversible saturable absorption. The closed aperture Z-scan of the samples exhibited negative nonlinearity, which was larger in magnitude in solid film compared to that in solution. The third order nonlinear susceptibility was found to be 2.00 and 2.34×10-6 (e.s.u) for the dye in solution and film at 0.05 mM concentration. The saturated output power for the dye in solution and film was found to be 1.2 and 0.8 mW respectively at 1.0 mM concentration. Conclusion: The dye doped in polymer can be utilized in optical limiting, low-power degenerate four wave mixing, data storage and grating applications.

Numerical Investigation of an Industrial Robot Arm Control Problem Using Haar Wavelet Series

Abstract: Problem statement: An error minimization in robot arm dynamics improves operations and performance of production systems. Many contributions have been made in area of robot dynamics since the earliest study more than two decades, but, a number of researchers are still contributing various principles and new techniques for the best use of robots in reality, especially in the field of industry, as this field of study is inexhaustible. This study attempted to analyze the performance of an industrial robot by comparing solutions obtained using RK method and Single-Term Haar Wavelet Series (STHWS) method. Exact solution of system of equations representing arm model of a robot had been compared with corresponding discrete solution at different time intervals. Absolute error between exact and discrete solutions had also been determined to suggest the method of improving performance of a robot. Approach: Haar wavelet had been applied extensively for signal processing in communications and proved to be a useful mathematical tool for dynamical systems. In this study, STWHS method had been used for solving differential equations. Result had been obtained and compared with exact solutions. Results: Error had been compared by exact solutions, RK and STHWS solutions were reported for non-singular systems and estimated as almost zero. The validation had been carried out with reference to earlier research output appeared in this field of study. Conclusion/Recommendations: For robot arm model selected for study, solution obtained by STHWS was found to be accurate from results.

Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

Abstract: Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temperature than diesel engine? This research was conducted to investigate the cylinder temperature of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: In this study, the combustion temperature was investigated in 7 cases engine speed. The engine speeds variation start from 1000 rpm until 4000 rpm with variation in 500 rpm. The engine conversion development and combustion temperature investigation was conducted at automotive laboratory, faculty of mechanical engineering, University Malaysia Pahang, Malaysia. Results: The results of the combustion temperature in the engine cylinder in variation engine speeds showed that diesel engine convert to CNG engine effect decrease the combustion temperature in the engine cylinder characteristics. Conclusion/Recommendations: In the low speed the conversion can be increase the combustion temperature, but the increasing engine speeds can be decrease the combustion temperature in the engine cylinder.

TEC and Scintillation Study of Equatorial Ionosphere: A Month Campaign over Sipitang and Parit Raja Stations, Malaysia

Abstract: Problem Statement: Ionospheric scintillations, which cause significant effects on satellite signals for communication and navigation, often takes place in equatorial region such as Malaysia. However, this disturbance are not fully understand due to few studies performed. This research reports the study and monitoring activity on Total Electron Content (TEC) and ionospheric scintillation in Malaysia using GPS measurements. Approach: One dual-frequency GPS receiver was positioned at the main station in Parit Raja, West Malaysia (1.86° N, 103.8° E) and Sipitang, East Malaysia (5.10° N, 115.56° E) respectively. Dual-frequency GPS data collected during the one-month ionospheric experimental campaign was used for TEC and scintillation computation and analysis. The TEC with 15 sec interval were computed from combined L1 and L2 code-pseudorange and carrier phase measurements. Whereas, the scintillation parameter S4 index was computed as a standard deviation of the received signal power normalized to average signal power every 60 sec on L1. A corrected S4 (without noise effects) was also computed and used in the analysis. Results: It was found that the daily maxima vTEC for Parit Raja (PR) ranged from 38-100 TECU, which is generally higher than those of Sipitang, which ranged from 30-42 TECU. However, a general consistency for both stations can be seen during the 1 month campaign period. Conclusions/Recommendations: In conclusion, these results show good agreement in the existence of the equatorial anomaly observed during moderate solar flux conditions and undisturbed geomagnetic condition. This will contributes to the knowledge of equatorial ionosphere and help in space weather condition. However, to better understand and characterize the ionosphere over Malaysia, more campaigns should be encouraged.

Investigation of the Behavior of Tailings Earthen Dam Under Seismic Conditions

Abstract: Problem statement: A number of tailings earthen dams have failed during past earthquakes. The failure of tailings dam ultimately results into the release of the stored tailings waste deposit in the surrounding locality. To reduce such damage of tailings earthen dam, a detail method of seismic analysis is very much essential which can be used reliably for the design and construction. Approach: To establish a detail method of static and seismic analysis for a tailings earthen dam, in this study both the static and seismic analysis were performed for a typical section of tailings earthen dam. The whole analysis was performed using various software packages like FLAC3D, TALREN 4, SEEP/W and SLOPE/W. Results: After FLAC3D analysis it was observed that under the seismic loading condition the maximum displacement of the dam is about 66.7 cm, whereas by using the Makdisi-Seed method the maximum displacement was obtained as 57 cm. FLAC3D analysis showed that the base level input acceleration gets amplified with the height of the dam and at the crest level the amplification is about three times. After slope stability analysis under seismic loading it was found that the factor of safety is 0.89, but under the static loading condition the minimum value of factor of safety was obtained as 1.22. Conclusion/Recommendation: From this analysis it was clear that the dam was unsafe under the seismic loading.

Cost-Effective Fabrication of Self-Made 1×12 Polymer Optical Fiber-Based Optical Splitters for Automotive Application

Abstract: Problem statement: Multimode fiber cables can conduct many light rays and can operate free of disruption and with a greater bandwidth than a wireless connection. However, due to a slight variation in the speed of the light rays through the multimode fiber, a signal transmitted by all of these rays becomes spread out. Consequently, the signals become broader and therefore fewer signals fit in the fiber, limiting the transmission capacity. These demands grow almost daily. Hence new ways of splitting methods must be found to satisfy all application demands, especially related to automotive application. Approach: Home-made 1×12 optical splitter based on polymer optical fiber material base is one of the most innovative technologies on optical component which can be applied on some useful application. A perform technique had been used to fabricate kind of splitter. In order to develop such an efficient optical device which can be integrated into the body of automotive field, research with a good specification-oriented study tent to be conduct and it must be passed through a well-planned fabrication technique together with a proper characterization process. Multimode Step-Index Polymer Optical Fiber (SI-POF) type made of polymethyl methacrylate (PMMA) with Ocore = 1 mm and NA: 0.50 fully utilized in this research, as PMMA is one of the most commonly used optical materials. This material has been chosen as a base of splitter body in a fused-taper-twisted shape, produced by a unique fabrication stages. PMMA-POF can easily be used near it operating temperature between -40°C to +115°C. Results: By injecting 650 nm wavelength of red LED, characterization process start plays an important role in investigating level of efficiency of the device. Some parameters, such as optical output power and power losses on the devices were observed. Although the maximum output power efficiency of the splitter is about 40% but it can be improved gradually through experience and practice. Conclusion: The fabrication process is simple, easy and suitable to be used by household. Moreover, the users can determine the size of the fabricated device themselves. The POF-based optical 1×12 splitter had been suggested to be applied into automobile application to overcome blind spot area tracking problem as a one of low-cost solution in the future and also in home networking to avoid the bottleneck occurs between ONU and electronic appliances, resulting increase the speedy of data communication.

Vision-Based Obstacle Avoidance of Mobile Robot Using Quantized Spatial Model

Abstract: Problem statement: Problem of moving a robot through unknown environment has attracted much attention over past two decades Such problems have several difficulties and complexities that are unobserved, besides the ambiguity of how this can be achieved since a robot may encounter obstacles of all forms that must be bypassed in an intelligent manner This research had been aimed to develop a system that was able to detect obstacles in a mobile robot's path using a single camera as only sensory input and to achieve the target point in optimized manner For this reason, algorithm which took total path length and safety into account was developed Approach: To control movement of robot from a starting to a target point inside the site where obstacles can obstruct the way of robot, real-time software-specially tailored for this purpose-was necessary to develop To analyze and to process scene images captured by a (vision) camera, camera was installed at the top over the center of site in a way that it covered whole site through which sufficient image information could be delivered From sequentially captured images that was manipulated through image processing and computer vision, the system built a representative site model, whose ingredients were gridded squares as a result of quantized spatial plane of site and then it began planning the desired routing path Results: For building a robot path, less computing effort was necessary because grid information was much easier to deal with than pixels and only a minimum amount of stored data of symbolic site model from current and previous state was necessary Conclusion: Using a quantized spatial domain, a less computational effort was necessary to control movement of robot with the ability of obstacle detection and avoidance

Analysis of the Tunnel Boring Machine Advancement on the Bologna-Florence Railway Link

Abstract: Problem statement: The high-velocity railway link between Bologna and Firenze (Italy) is today under construction and several tunnels have to be excavated for this purpose, some of these using TBMs. A small diameter tunnel, named Cunicolo ginori, was realized by TBM parallel to a large railway tunnel (Vaglia), at the distance of only 35 m. Approach: The Vaglia tunnel had been excavated by conventional methods and provided, thanks to a detailed survey and a systematic geotechnical monitoring (rock quality evaluation and convergence measurements) the characterization data of the crossed rock mass; moreover the TBM performance data in Cunicolo ginori were continuously monitored. A tunnel stretch, 587 m long, was recorded and the analysis of the data from both surveys allowed to correlate the geomechanical parameters of the rock-mass to the TBM performances (net advancement rate, thrust, specific energy). Results: Based on this large amount of data a new system to predict the net TBM advancement rate for a tunnel in rock masses of known geological and geomechanical characteristics was then developed. Also the Utilization Coefficient (CU) can be correlated to the rock quality Indices: The net advance rate and the utilization coefficient provide a mean to foresee the gross advancement rate and to evaluate the suitability of a machine for the excavation of a tunnel. Conclusion: In this study, an analysis had been carried out on about 587 m of a service tunnel, excavated by a TBM in a flysch formation.

Numerical Study on the Performance Characteristics of Hydrogen Fueled Port Injection Internal Combustion Engine

Abstract: This study was focused on the engine performance of single cylinder hydrogen fueled port injection internal combustion engine. GT-Power was utilized to develop the model for port injection engine. One dimensional gas dynamics was represented the flow and heat transfer in the components of the engine model. The governing equations were introduced first, followed by the performance parameters and model description. Air-fuel ratio was varied from stoichiometric limit to a lean limit and the rotational speed varied from 2500 to 4500 rpm while the injector location was considered fixed in the midway of the intake port. The effects of air fuel ratio, crank angle and engine speed are presented in this study. From the acquired results show that the air-fuel ratio and engine speed were greatly influence on the performance of hydrogen fueled engine. It was shown that decreases the Brake Mean Effective Pressure (BMEP) and brake thermal efficiency with increases of the engine speed and air-fuel ratio however the increase the Brake Specific Fuel Consumption (BSFC) with increases the speed and air-fuel ratio. The cylinder temperature increases with increases of engine speed however temperature decreases with increases of air-fuel ratio. The pressure fluctuations increased substantially with increases of speed at intake port however rise of pressure at the end of the exhaust stroke lead to reverse flow into the cylinder past exhaust valve. The fluctuation amplitude responded to the engine speed in case of exhaust pressure were given less than the intake pressure. The volumetric efficiency increased with increases of engine speed and equivalent ratio. The volumetric efficiency of the hydrogen engines with port injection is a serious problem and reduces the overall performance of the engine. This emphasized the ability of retrofitting the traditional engines with hydrogen fuel with minor modifications.

Optimal location of static var compensator device for damping oscillations

Abstract: Problem statement: Static Var Compensators (SVC) devices are used to improve voltage and reactive power conditions in AC systems. An additional task of SVC is to increase transmission capacity as result of power oscillation damping. The effectiveness of this controller depends on its optimal location and proper signal selection in the power system network. A residue factor had been proposed to find the optimal location of the SVC controllers to damp out the inter-area mode of oscillations. Approach: The proposed residue factor was based on the relative participation of the parameters of SVC controller to the critical mode. A simple approach of computing the residue factor had been proposed, which combined the linearized differential algebraic equation model of the power system and the SVC output equations. Input-output controllability analyses were used to assess the most appropriate input signals (stabilizing signal) for SVC device. Results: The placements of SVC controller had been obtained for the base case as well as for the critical contingency cases. Conclusion: The effectiveness of the proposed method was demonstrated on 25 bus of south Malaysian power system.

On the Use of Rolling Element Bearings' Models in Precision Maintenance

Abstract: Problem statement: Rolling element bearings form a very important part of machinery. The increasing demands on their continuous reliable operation under diverse environments make maintenance a very important step towards the efficient use of them. To this end, precision maintenance is a very useful practice, since it deals not only with finding a possible fault of a machine, but also with the identification of its cause and the suggestion of possible preventive measures and corrective actions. In order to better apply precision maintenance techniques though, it is necessary to have a very good insight of the bearings' operation. Approach: This study described how the analytical models of the operation of rolling element bearings could be used for the better utilization of precision maintenance in practice. It also presented briefly these analytical models, together with a detailed description of how their results can be used in precision maintenance practice. Results: The results of a typical example were given, which showed that the proposed analysis gives an insight of the bearing operation, necessary for the better understanding of the root cause of possible failures. Conclusion: This research come to the conclusion that the knowledge of the origin of failures that could be the result of bearing's theoretical models, could be very helpful for the application of precision maintenance practices, since it could lead to the correction of the cause of each failure and thus the bearing will not fail again for the same reason.

Effect of Corrosion Damage on the Ductility Performance of Concrete Columns

Abstract: Problem statement: An experimental investigation was carried out on reinforced concrete columns with corroding reinforcement to assess the residual strength and ductility performance of columns Approach: An accelerated corrosion regime of different degrees of corrosion damage of 10 and 25% were induced in the steel reinforcement of concrete columns The columns were then tested under uni-axial compression until failure Results: The results showed a marked reduction in axial strength and ductility of the corroded concrete columns Conclusion/Recommendations: The increase in corrosion intensity decreased the axial load carrying capacity of the columns and hence reduction in ductility of the corroded columns

Experimental Study of Flow Structures of Circular Pulsating Air Jet

Abstract: Problem Statement: Applications of impingement jets in industry for heating and cooling purposes requires a high convective heat transfer coefficient. Numerous studies have been conducted to improve the convective heat transfer coefficient for a steady impinging jet. A pulsating jet has a very high potential in replacing steady jet after it been found able to increase the heat transfer coefficients at certain pulsating frequencies. The objectives of this study were to; (i) determine the velocity profile of a circular pulsating air jet at different pulse frequencies and Reynolds Number using a rotating valve pulse jet system and (ii) to compare the normalized steady and pulsed jet velocity at highest Reynolds number of 32 000 and highest pulsating frequency of 80Hz. Approach: Pulsation of the air jet was produced by a rotating cylinder valve mechanism at frequencies between 10-80 Hz. Flow structures of the heated steady and pulse single circular axisymmetric air jet velocity were measured using a calibrated hot-wire anemometer and presented in non-dimensional form. The measurements were carried out at three different Reynolds numbers which was set at 16000, 23300 and 32000. The jet exit velocity profile for all the test frequency is determined by plotting the graph of radial distance against the non-dimensional jet exit velocity. Results: The corresponding Reynolds number in this test is based on time-averaged centerline velocity. The results of the velocity measurement were plotted side by side using non-dimensional parameters in order to make direct comparison of the velocity profile at different frequencies and Reynolds numbers. Stagnation point velocities are the same for steady and pulsating jet for all pulse frequencies. As the radial distance from the stagnation point increases, pulsating velocity increases between 20-30% from radial distance of 2-22 mm. Conclusion: Results of the flow structures plotted show a distinctive exit air jet profile which can affect the impingement heat transfer characteristics. This was the result of enhanced turbulence intensity due to pulsating jet produced by the rotating cylinder. From the jet exit velocity profile obtained, it is found that mass flow rate for different test frequencies are slightly different due to the difference in the local velocity measurement affected by the pulses. The jet exit velocity profile data will be used to form a correlation between the pulsating jet velocity and heat transfer data.

Prediction Studies for the Performance of a Single Cylinder High Speed Spark Ignition Linier Engine with Spring Mechanism as Return Cycle

Abstract: Problem statement: Most concepts of linear engines were constructed a s opposed pistons with complicated control devise to drive the engine s. The advantage of the engines was their high overall efficiency. Approach: Although the efficiency was higher than conventiona l engine, however, it did not be applied yet, because the design of th ese engines was not only difficult to fabricate, bu t also it has little chance to compete the traditiona l engines in the market. Spring is adopted as a ret urn force of the piston movement technique. Results: The unique of using spring as return cycle is the main characteristic of these engines. However, stro ke of the engine is not constant as in the traditio nal engine. The problem is that, the expansion stroke i s depending on thrust force of piston. On the other hand, the engine needs to operate in variable speed and load. This study is a prediction of the performance of both rotational and linear engines. Conclusion/Recommendations: The result of the examination can be used as return cycle design data of a single cylinder linear engine with spring device. As a result, the spring mechanism can be ad opted to be used as return cycle in linear engine.

Robust of doppler centroid for mapping sea surface current by using radar satellite data

Abstract: Problem statement: Sea surface current retrieving from Synthetic Apert ure Radar (SAR) is required standard methods due to the complexity of sea surface ocean imaging in SAR data. In this context, various analytical models have been develo ped which describe overall effects of sea surface roughness on the Doppler signal mechanisms. Nevertheless, such models are limited in the complexity of the sea surface current estimation that can be u sed. In fact, the resolution of the sea surface Dop pler velocity in azimuth direction is typically coarser as compared to the normalized radar cross section image. Approach: This study introduced a new method to retrieve sea surface current from RADARSAT-1 SAR Standard beam mode (S2) data. The method was based on the utilization of the Wavelength Diversity Ambiguity Resolving (WDAR) and Multi Look beat Frequency (MLBF) algorithms to remove Doppler centroid (f DC ) ambiguity. Results: The result showed that the proposed methods are able to correct Doppler centroid (f DC ) ambiguity and produced fine spatial sea surface current variations in S2 mode data. The current vel ocities were ranged between 0.18 and 0.78 m sec -1 with standard error of 0.11 m sec -1 . Conclusion: In conclusion, RADARSAT-1 SAR standard beam mode (S2) data can be utilized to retrieve real tim e sea surface current. Both WDAR and MLBF algorithms are able to provide accurately informati on on Doppler Centroid (fDC ) in which accurately real time sea surface current can be retrieved from SAR data.

Mathematical Modeling of the Three Phase Induction Motor Couple to DC Motor in Hybrid Electric Vehicle

Abstract: Problem statement: With emphasis on a cleaner environment and efficient operation, vehicles today rely more and more heavily on electrical power generation for success. Approach: Mathematical modeling the components of the HEV as the three phase induction motor couple to DC motor in hybrid electric vehicle was introduced. The controller of Induction Motor (IM) was designed based on input-output feedback linearization technique. It allowed greater electrical generation capacity and the fuel economy and emissions benefits of hybrid electric automotive propulsion. Results: A typical series hybrid electric vehicle was modeled and investigated. Conclusion: Various tests, such as acceleration traversing ramp and fuel consumption and emission were performed on the proposed model of 3 phase induction motor coupler DC motor in electric hybrid vehicles drive.

Evolutionary Algorithm Definition

Abstract: Problem statement: Most resent evolutionary algorithms work under weak theoretical basis and thus, they are computationally expensive. Approach: This study discussed the use of new evolutionary algorithm for automatic programming, based on theoretical definitions of program behaviors. Evolutionary process adapted fixed and self-organized input-output specification of the problem, to evolve good finite state machine that efficiently satisfies these specifications. Results: The proposed algorithm enhanced evolutionary process by simultaneously solving multi-parts from the same problem. Conclusion: The probability that the algorithm will converge to the optimal solution was highly enhanced when decomposing the main problem into multi-part.

Effect of Diesel Engine Converted to Sequential Port Injection Compressed Natural Gas Engine on the Cylinder Pressure vs Crank Angle in Variation Engine Speeds

Abstract: The diesel engine converted to compressed natural gas (CNG) engine effect is lower in performance. Problem statement: The hypothesis is that the lower performance of CNG engine is caused by the effect of lower in engine cylinder pressure. Are the CNG engine is lower cylinder pressure than diesel engine? This research is conducted to investigate the cylinder pressure of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: The research approach in this study is by convert the diesel engine to multi point injection dedicated CNG engine. The engine conversion is by changed the diesel fuel to CNG fuel, changed the injection fuel system, changed the ignition system, modified piston to reduce the compression ratio and added throttle to in intake port. If the development is completed, the engine cylinder pressure is investigated. In this study, the cylinder pressure is investigated in 7 cases engine speed from 1000 to 4000 rpm with range in 500. Results: The research results are cylinder pressure and maximum pressure of CNG engine compared to diesel engine in 1000 to 4000 rpm engine speed. Conclusion/Recommendations: Effect of diesel engine converted to CNG engine is decrease the cylinder pressure. The further research is needed to find the higher performance of CNG engine.

Diesel Engine Convert to Port Injection CNG Engine Using Gaseous Injector Nozzle Multi Holes Geometries Improvement: A Review

Abstract: The objective of this study was to review the previous research in the development of gaseous fuel injector for port injection CNG engine converted from diesel engine. Problem statement: The regular development of internal combustion engines change direction to answer the two most important problems determining the development trends of engines technology and in particular, their combustion systems. They were environmental protection against emission and noise, shortage of hydrocarbon fuels, specific fuel consumption and other technical and economic parameters. Approach: Several alternative fuels has been recognized as having a significant potential for producing lower overall pollutant emissions compared to diesel fuel. Natural gas, which composed predominately by identified as a leading candidate for transportation applications among these fuels for availability, environmental compatibility and natural gas is that it can be used in conventional diesel engines. Results: Some advantages of CNG as a fuel are octane number is very good for SI engine fuel, engines can be operate with a high compression ratio, less engine emissions and less aldehydes. In the diesel engines converted or designed to run on natural gas with the port injection (sequential) or trans-intake valve-injection system, a high-speed gas jet was pulsed from the intake port through the open intake valve into the combustion chamber, where it caused effects of turbulence and charge stratification particularly at engine parts load operations. The system was able to diminish the cyclic variations and to expand the limit of lean operation of the engine. The flexibility of gas pulse timing offers the potential advantage of lower emissions and fuel consumption. There are several advantages of port injection. The better possibility CNG engine is to equalize the air-fuel ratio of the cylinders, optimization of the gas injection timing and of the gas pressure for different operating conditions. Conclusion: The fuel nozzle injector multi holes geometries development was to produce optimum fuel air mixing and increasing the volumetric efficiency of the engine that will promote a comparable engine performance and efficiency.

Pneumatic and Hydraulic Systems in Coal Fluidized Bed Combustor

Abstract: Problem statement: This study designed the pneumatic and hydraulic systems in coal fluidized bed combustor. These are fluidization of silica sand bed material, Air distributor, centrifugal fan, electric motor power drive and surface heat exchanger. Approach: The effects of increased gas velocity on silica sand and the resultant drag force formed the basic equations in fluidization. Air distributor was introduced to achieve pressure drop across the beds. Results: The constructed centrifugal fan was driven by selected electric motor based on pressure and temperature changes in the reactor. The dimensions of the heat transfer tube were calculated from fluid flow and energy balance equations. The values obtained were as the follows: Fluidization velocity (1.54 m sec-1), gas velocity through orifice (29.52 m sec-1), the fan electric motor (2 KW, 3 ph at 1500 pm), the steam temperature obtained was 160°C from water ambient temperature of 30°C and tube length 22 m was coiled into levels in the combustor. Conclusion/Recommendation: Precise specifications of pneumatic and hydraulic systems will adequately address the environment concern of coal fired power supply as a method to address epileptic power supply in Nigeria.

Robust Position Controller for a Permanent Magnet Synchronous Actuator

Abstract: Problem statement: The present study investigated with the application of a robust control scheme to improve the performance of a simplified indirect field oriented for small power surface mounted Permanent Magnet (PM) synchronous actuators. Approach: The suggested model was implemented using a simplified state feedback with no need to measure the current values to compute the control algorithm. Results: The current values were estimated by an accurate prediction model estimated from real input/output data. The suggested control scheme was enabling the possibility to perform a position controller by using only a position sensor. Conclusion: The performance of the controller was evaluated and validated by digital simulation using SIMNON package and the usefulness of the suggested method was proved.

Improved Coupled Tank Liquid Levels System Based on Swarm Adaptive Tuning of Hybrid Proportional-Integral Neural Network Controller

Abstract: Problem statement: Accuracy and stability of many systems in chemical and process industries which has Two-Input Two-Output (TITO) is one of the key factors of process which have cross coupling between process input and output. Approach: Unlike traditional neural network weight adaptation using gradient descent method, Particles Swarm Optimization (PSO) technique was utilized for adaptive tuning of neural network weights adjustment and fine tuning the controller’s parameters. Design approach for controlling liquid levels of Coupled Tank TITO system by using hybrid PI-Neural Network (hybrid PI-NN) controllers. Results: Tuning method for parameters of improved hybrid PI-NN controller was also discussed. Conclusion: Performances of proposed method also compared with PID-NN controllers, it was shown that hybrid PI-NN controller exhibited better performance in terms of transient response analysis.

Converting of Matter to Nuclear Energy by AB-Generator

Abstract: Problem statement: Researcher offered a new nuclear generator which a llowed to convert any matter to nuclear energy in accordance with Ein stein equation E = mc 2 . The method was based upon tapping the energy potential of a Micro Black Hole (MBH) and Hawking radiation created by this MBH. Researcher did not meet the idea and its research in literatur e to develop the method for getting a cheap energy. Approach: As is well-known, vacuum continuously produced virtual pairs of particles and antiparticles, in particular, photons and anti- photons. MBH event horizon allowed separating them. Anti-photons can be moved to MBH and be annihilated, decreasing mass of MBH, resulting photons leave the MBH neighborhood as Hawking radiation. The offered nuclear generator (named by Researcher as AB-generator) utilized Hawking radiation and injected the matter into MBH and kept MBH in a stable state with near-constant mass. Results: AB-generator can be produced gigantic energy outputs and should be cheaper than a convent ional electric station by a factor of hundreds of times. One also may be used in aerospace as a photo n rocket or as a power source for many vehicles. Conclusion: Many scientists expect Large Hadron Collider at CE RN may be produced one MBH every second. A technology to capture them may be developed; than they may be used for the AB-generator.