Vol. 5 No. 2 (2012)
Articles
Abstract: The paper aimed to use the old rubber tires which causing a big problem to the environment and its need much money and efforts to disposing it safely. In Iraq there is more than 2 million used tires disposed to the environment yearly whereas in the US there is 2 billion one. One of the tyre recycling methods , is the use of tyre plies to produce a new rubber parts used in the engineering and industrial purposes as the bridge and machine dampers , this trend of recycling doesn’t take a sufficient care comparing with the other methods . In the current research the study focusing on the mechanical properties of the used tyres and comparing them with the new one , and suggesting a new method to use the recycled tyres as an engineering parts ( for example the coupler lied between the IC engine and the generating head in the generators . One of the results obtained from the experiments, there is no significant difference between the mechanical properties of the old and new tyres , (in the tensile test – the breaking force of the tensile specimen of the new tyre is 137 N and for the old one is 113.27 N , but they are same in the elongation) . A dimensions of a flexible coupling suggested as a computational example and when using the experimental value of shear stress for the cord-rubber composite lamina (3.82*106N/m2)the calculation showing that the number of strips for the coupler should be two with 2 ply lamina or 4 with one ply lamina at engine power less than 30 Kw .
Abstract: The paper aimed to use the old rubber tires which causing a big problem to the environment and its need much money and efforts to disposing it safely. In Iraq there is more than 2 million used tires disposed to the environment yearly whereas in the US there is 2 billion one. One of the tyre recycling methods , is the use of tyre plies to produce a new rubber parts used in the engineering and industrial purposes as the bridge and machine dampers , this trend of recycling doesn’t take a sufficient care comparing with the other methods . In the current research the study focusing on the mechanical properties of the used tyres and comparing them with the new one , and suggesting a new method to use the recycled tyres as an engineering parts ( for example the coupler lied between the IC engine and the generating head in the generators . One of the results obtained from the experiments, there is no significant difference between the mechanical properties of the old and new tyres , (in the tensile test – the breaking force of the tensile specimen of the new tyre is 137 N and for the old one is 113.27 N , but they are same in the elongation) . A dimensions of a flexible coupling suggested as a computational example and when using the experimental value of shear stress for the cord-rubber composite lamina (3.82*106N/m2)the calculation showing that the number of strips for the coupler should be two with 2 ply lamina or 4 with one ply lamina at engine power less than 30 Kw .
Abstract: This research focuses on idea to rise quality of illumination in product halls in industrial foundation to get best product operation with reduction a product cost by reduce electrical energy needed to system. During research analysis of a illumination system in the dermal industrial factory halls that are doing shows depart from standards and abilities to improve currently system with economize electrical energy.
Abstract: This research focuses on idea to rise quality of illumination in product halls in industrial foundation to get best product operation with reduction a product cost by reduce electrical energy needed to system. During research analysis of a illumination system in the dermal industrial factory halls that are doing shows depart from standards and abilities to improve currently system with economize electrical energy.
Abstract: Wear is a phenomenon which is surface materials damage or loss between two contact solids surfaces in sliding, rolling, or impact movement. In most cases, wear is caused by the interaction of surface asperities. To reduce the energy loss and equipment damage generated due to the mechanical parts friction in the operation, around the world is stepping up developing appropriate lubricants and lubrication technology. Molybdenum is one of the major refractory metals (metals with very high resistance to heat and wear). As already noted, for lubricant compositions as fillers can be used soft powder (anti-friction) of metals – nickel. This work focuses on studying an urgency and favorable prospects of practical use of firm powder additives on the basis of MoS2 which particles are coated with one layer of soft metal (Ni), and their effect on tribological characteristics of lubricant oil (SAE 50) at a range of concentration (2 – 8) wt%. Optimum lubricating effect concluded on the level of concentration of the composite additive powder in the range of (3.5 – 4.5) wt %, by the formation of protective boundary layer between sliding tribosurfaces that prevents wear. Tribological characteristics significantly improved i.e.friction coefficient may drop about (1.5-2) times, and the wear rate about (3-3.5) times compared with the case of usig the lubricant oil without additives.
Abstract: Wear is a phenomenon which is surface materials damage or loss between two contact solids surfaces in sliding, rolling, or impact movement. In most cases, wear is caused by the interaction of surface asperities. To reduce the energy loss and equipment damage generated due to the mechanical parts friction in the operation, around the world is stepping up developing appropriate lubricants and lubrication technology. Molybdenum is one of the major refractory metals (metals with very high resistance to heat and wear). As already noted, for lubricant compositions as fillers can be used soft powder (anti-friction) of metals – nickel. This work focuses on studying an urgency and favorable prospects of practical use of firm powder additives on the basis of MoS2 which particles are coated with one layer of soft metal (Ni), and their effect on tribological characteristics of lubricant oil (SAE 50) at a range of concentration (2 – 8) wt%. Optimum lubricating effect concluded on the level of concentration of the composite additive powder in the range of (3.5 – 4.5) wt %, by the formation of protective boundary layer between sliding tribosurfaces that prevents wear. Tribological characteristics significantly improved i.e.friction coefficient may drop about (1.5-2) times, and the wear rate about (3-3.5) times compared with the case of usig the lubricant oil without additives.
Abstract: The effect of annealing process on corrosion resistance for aluminum (2024-T3) alloy is investigated. Samples of this alloy had been manufactured with dimensions (1.5*1.5*0.3) cm according to ASTM specifications. The annealing process applied by heating the metal in three deferent times; 270°C for two hours, 400°C for half hour and 350°C for one hour. After that the X-Ray Diffraction test has been done in order to know the phases resulted. The electrochemical corrosion test has been done by fixing the potential of the cell and changing it, the potential is chosen depending on open circle and comparing it with the standard metal potential of electrochemical series then adding 100 volt to show the cathode and anode behavior of metal, it had been found that the corrosion average resistance affected by temperature degree and time of the process, it had been noticed that increasing annealing temperature the corrosion resistance of alloy decreased, specially at 400°C, the heat treatment at the temperature 270°C was the best.
Abstract: The effect of annealing process on corrosion resistance for aluminum (2024-T3) alloy is investigated. Samples of this alloy had been manufactured with dimensions (1.5*1.5*0.3) cm according to ASTM specifications. The annealing process applied by heating the metal in three deferent times; 270°C for two hours, 400°C for half hour and 350°C for one hour. After that the X-Ray Diffraction test has been done in order to know the phases resulted. The electrochemical corrosion test has been done by fixing the potential of the cell and changing it, the potential is chosen depending on open circle and comparing it with the standard metal potential of electrochemical series then adding 100 volt to show the cathode and anode behavior of metal, it had been found that the corrosion average resistance affected by temperature degree and time of the process, it had been noticed that increasing annealing temperature the corrosion resistance of alloy decreased, specially at 400°C, the heat treatment at the temperature 270°C was the best.
Abstract: Polarization shift keying (PolSK) and advanced modulation formats represent the future in development of high speeds communications. In this paper the feasibility of PolSK systems combining multilevel modulation is studied. The performance of 40 Gbit/s PolSK systems is tested by a optical simulation software. Optimums values for set the signals and eye diagrams are evaluated. Furthermore numerical simulations are performed to evaluate the transmission performance of a 40 Gbit/s PolSK system, and a transmission through various optical fiber lengths is demonstrated.
Abstract: Polarization shift keying (PolSK) and advanced modulation formats represent the future in development of high speeds communications. In this paper the feasibility of PolSK systems combining multilevel modulation is studied. The performance of 40 Gbit/s PolSK systems is tested by a optical simulation software. Optimums values for set the signals and eye diagrams are evaluated. Furthermore numerical simulations are performed to evaluate the transmission performance of a 40 Gbit/s PolSK system, and a transmission through various optical fiber lengths is demonstrated.
Abstract: The paper studies the distribution of stresses and strains of deep drawing process until the failure. The process is modeled with its four basic parts: the punch, the die, the holder and the blank. As the study concentrates on the blank, the blank in modeled as an elastic body, where the other parts are modeled as rigid bodies .The study is performed on two sets: the first set with Von-Mises plastic criteria & the second set with Hill criteria to take the anisotropy into consideration. For both set the coefficient of friction is set to constant value. The study focuses on the failure analysis by changing the punch stroke until the value of the blank diameter to monitor the thinning of the cup thickness. Due to importance of the springback in metal forming which determines the residual stress inside the blank, model of springback is added. The study is performed using the finite element code ANSYS 11 .The effect of entropy; stroke length and springback on the deep drawing process can be no test on the behavior on the metal forming.
Abstract: The paper studies the distribution of stresses and strains of deep drawing process until the failure. The process is modeled with its four basic parts: the punch, the die, the holder and the blank. As the study concentrates on the blank, the blank in modeled as an elastic body, where the other parts are modeled as rigid bodies .The study is performed on two sets: the first set with Von-Mises plastic criteria & the second set with Hill criteria to take the anisotropy into consideration. For both set the coefficient of friction is set to constant value. The study focuses on the failure analysis by changing the punch stroke until the value of the blank diameter to monitor the thinning of the cup thickness. Due to importance of the springback in metal forming which determines the residual stress inside the blank, model of springback is added. The study is performed using the finite element code ANSYS 11 .The effect of entropy; stroke length and springback on the deep drawing process can be no test on the behavior on the metal forming.
Abstract: Highway traffic safety is an important area in transportation engineering. Highway intersections are nodes of road networks and accident-prone locations. They are the places where vehicles coming from different approaches and moving towards different directions interact and conflict with each other. Due to the conflicts from all users, more traffic crashes could happen at unsignalized intersection as compared with roadway segments. Popular methods which are based upon traffic accidents and traffic conflicts are proved to be effective in certain circumstances, but difficulty in data collection of traffic crashes and subjective judgment and determination of traffic conflict constrain their applications. This paper introduces an approach to evaluate and improve unsignalized intersection safety performance. This method is fully based on the existing conditions of unsignalized intersection, including geometric design, sight distance, pavement surface conditions, traffic control devices, and lighting, etc. Different from the crash-based and conflict-based methods, this approach is a non-crash and non-conflict based analysis method. This approach needs to go through a field survey to unsignalized intersection to be evaluated. In this approach, a safety index is introduced to give a diagnostic summary of the safety performance degree of unsignalized intersections. Corresponding countermeasures are ranked and recommended based on the cost benefit analysis. In this paper, the approach (called diagnostic approach) is practically applied to evaluate and improve the safety performance of some unsignalized intersections in Fallujah city of Iraq.
Abstract: Highway traffic safety is an important area in transportation engineering. Highway intersections are nodes of road networks and accident-prone locations. They are the places where vehicles coming from different approaches and moving towards different directions interact and conflict with each other. Due to the conflicts from all users, more traffic crashes could happen at unsignalized intersection as compared with roadway segments. Popular methods which are based upon traffic accidents and traffic conflicts are proved to be effective in certain circumstances, but difficulty in data collection of traffic crashes and subjective judgment and determination of traffic conflict constrain their applications. This paper introduces an approach to evaluate and improve unsignalized intersection safety performance. This method is fully based on the existing conditions of unsignalized intersection, including geometric design, sight distance, pavement surface conditions, traffic control devices, and lighting, etc. Different from the crash-based and conflict-based methods, this approach is a non-crash and non-conflict based analysis method. This approach needs to go through a field survey to unsignalized intersection to be evaluated. In this approach, a safety index is introduced to give a diagnostic summary of the safety performance degree of unsignalized intersections. Corresponding countermeasures are ranked and recommended based on the cost benefit analysis. In this paper, the approach (called diagnostic approach) is practically applied to evaluate and improve the safety performance of some unsignalized intersections in Fallujah city of Iraq.
Abstract: The method in this paper depends on transmitting and receiving the sub image by hiding it inside envelope image (steganography process), using wavelet domain. This method depends on hiding sub-image inside the details information (high resolution) of the covered image after taking the discrete wavelet transformation applied on a covered image. The proposed method for hiding and transmitting the sub image inside the cover image is done by shrinking its values in order to accommodate high resolution details of the discrete wavelet transform of the cover image, after this process is a accomplished, it must rearrange the shrieked sub image information by coding rows and columns positions for hiding inside the high resolution details of the wavelet domain of the cover image. Taking the inverse wavelet transform for the new cover image included with the hide information of the sub image information (transmitting steganography process). Here the restore operation of the cover image is ready for sending process at any transmission port. The proposed method for receiving the cover image is done by taking the new covered image and applying wavelet transform again to get the details information that are included the coded information of the transmitted sub image. Then by encoding for the receiving high details information of the wavelet transform and re arrangement for both row and column as mentioned above but in inverse way, this will lead to the original shrinked sub image. Applying stretching process (d- shrinking) on a gated sub image, the sub image will get at the end of this step. Finally, calculate the mean square error in tables to calculate error rate between different sub images that hided in the cover image and compute the error rate values when calculated according to restore the cover image and compare the result. Error rate is less than or equal to .003 when calculated using the cover image and the restore version of the cover image, when hiding different sub images inside it.
Abstract: The method in this paper depends on transmitting and receiving the sub image by hiding it inside envelope image (steganography process), using wavelet domain. This method depends on hiding sub-image inside the details information (high resolution) of the covered image after taking the discrete wavelet transformation applied on a covered image. The proposed method for hiding and transmitting the sub image inside the cover image is done by shrinking its values in order to accommodate high resolution details of the discrete wavelet transform of the cover image, after this process is a accomplished, it must rearrange the shrieked sub image information by coding rows and columns positions for hiding inside the high resolution details of the wavelet domain of the cover image. Taking the inverse wavelet transform for the new cover image included with the hide information of the sub image information (transmitting steganography process). Here the restore operation of the cover image is ready for sending process at any transmission port. The proposed method for receiving the cover image is done by taking the new covered image and applying wavelet transform again to get the details information that are included the coded information of the transmitted sub image. Then by encoding for the receiving high details information of the wavelet transform and re arrangement for both row and column as mentioned above but in inverse way, this will lead to the original shrinked sub image. Applying stretching process (d- shrinking) on a gated sub image, the sub image will get at the end of this step. Finally, calculate the mean square error in tables to calculate error rate between different sub images that hided in the cover image and compute the error rate values when calculated according to restore the cover image and compare the result. Error rate is less than or equal to .003 when calculated using the cover image and the restore version of the cover image, when hiding different sub images inside it.
Abstract: The quantification of contact area and pressure distribution in a bolted joint is essential information, as it determines the integrity of the joint. Most of Current bolted joint designs are based on approximate solutions of the pressure distribution in complicated hand formulas. The purpose of the present paper is to find a simplified analytic expression for the stiffness of the clamped member. The derivation is based on the principle of superposition. The stiffness of the conical solid member is estimated first and from which the stiffness of the hole material is subtracted. The results obtained were accurate and proved to agree with formulas that are widely used.
Abstract: The quantification of contact area and pressure distribution in a bolted joint is essential information, as it determines the integrity of the joint. Most of Current bolted joint designs are based on approximate solutions of the pressure distribution in complicated hand formulas. The purpose of the present paper is to find a simplified analytic expression for the stiffness of the clamped member. The derivation is based on the principle of superposition. The stiffness of the conical solid member is estimated first and from which the stiffness of the hole material is subtracted. The results obtained were accurate and proved to agree with formulas that are widely used.
Abstract: Natural convection of an air filled partitioned rectangular enclosure is studied numerically. Top and bottom of the enclosure are adiabatic; the two vertical walls are isothermal. Two perfectly insulated baffles were attached to its horizontal walls at symmetric position. The flow is assumed to be two-dimensional. The discretized equations were solved by finite volume method.The study was performed for different values of Rayleigh numbers Ra ( ), baffles length and position ( )(0-0.8,0.2-0.8) and aspect ratios of the enclosure. The effect of ( and on heat transfer and flow were addressed.Two different patterns of the flow field were observed. The first is the flow circulate in single primary vortex strangled by two trapped fluids and the second pattern is the flow consist of two vortexes separated by one trapped fluid.With increasing of Ra heat transfer rate(Nusselt number)increased and for increasing baffles length the heat transfer rate decreases. The numerical results of the values of average Nusselt number and maximum absolute stream function have been confirmed by comparing it with similar previous works using the same boundary conditions. Good agreement was obtained.
Abstract: Natural convection of an air filled partitioned rectangular enclosure is studied numerically. Top and bottom of the enclosure are adiabatic; the two vertical walls are isothermal. Two perfectly insulated baffles were attached to its horizontal walls at symmetric position. The flow is assumed to be two-dimensional. The discretized equations were solved by finite volume method.The study was performed for different values of Rayleigh numbers Ra ( ), baffles length and position ( )(0-0.8,0.2-0.8) and aspect ratios of the enclosure. The effect of ( and on heat transfer and flow were addressed.Two different patterns of the flow field were observed. The first is the flow circulate in single primary vortex strangled by two trapped fluids and the second pattern is the flow consist of two vortexes separated by one trapped fluid.With increasing of Ra heat transfer rate(Nusselt number)increased and for increasing baffles length the heat transfer rate decreases. The numerical results of the values of average Nusselt number and maximum absolute stream function have been confirmed by comparing it with similar previous works using the same boundary conditions. Good agreement was obtained.
Abstract: This research is devote to a description of the methods available for the analysis of unsteady flows in pumping stations and their associated hydraulic systems. There are two basic approaches to the solution of unsteady internal flows: solution in the time domain and in the frequency domain. The traditional time domain methods for hydraulic systems are the most important that many unsteady hydraulic system problems can and should be treated by the time domain or “water-hammer” methods. Another approach is frequency domain method, it is sufficient to recognize that one practical advantage of this method is the capability of incorporation of experimentally obtained dynamic information and the greater simplicity of the experiments required to obtain the necessary dynamic data, the disadvantage of frequency domain is that the method are limited to small linear perturbations in the flow rate. Two types of networks are tested in this research, example (1) represents very simple network without any apparatus, and example (2) network containing some complexity and containing intakes, valves, and other apparatus. The results in example (1) identical for both methods, but in example (2) the results showing clear differences for the two approaches.
Abstract: This research is devote to a description of the methods available for the analysis of unsteady flows in pumping stations and their associated hydraulic systems. There are two basic approaches to the solution of unsteady internal flows: solution in the time domain and in the frequency domain. The traditional time domain methods for hydraulic systems are the most important that many unsteady hydraulic system problems can and should be treated by the time domain or “water-hammer” methods. Another approach is frequency domain method, it is sufficient to recognize that one practical advantage of this method is the capability of incorporation of experimentally obtained dynamic information and the greater simplicity of the experiments required to obtain the necessary dynamic data, the disadvantage of frequency domain is that the method are limited to small linear perturbations in the flow rate. Two types of networks are tested in this research, example (1) represents very simple network without any apparatus, and example (2) network containing some complexity and containing intakes, valves, and other apparatus. The results in example (1) identical for both methods, but in example (2) the results showing clear differences for the two approaches.