Dependency in systems is one of the problems that reliability faces. Dependence increases the probability of failure and can affect the performance of a system; Therefore, it is very important to study and understand the consequences when designing, operating and maintaining the system. Regardless of the dependency, reliability is optimistically estimated and the system fails sooner than expected. In the rail industry, subsystems show a high level of dependence due to their high dynamics and complexity. Failure of any of the subsystems can affect the performance of the entire network and sometimes have irreparable consequences. Identifying dependencies and dependent failures based on the block diagram of reliability and the structure of the rail system can affect the more accurate prediction of reliability and reduce the subsequent consequences. This paper presents a new mathematical model for predicting reliability in the rail industry by considering common cause failure. Various methods have been introduced to estimate the common cause failure coefficient. The results show an increase in accuracy in predicting reliability.

The purpose of this paper is troubleshooting, adjusting and analysis of a useful diesel engine fuel injector from common rail system with experimental and laboratory investigations. In the new diesel engines, the fuel common rail system has an important contribution to increase efficiency and improve engine performance. The injector as one of the most important and advanced components in the common rail system has numerous failures in test engine. For this purpose, different parts of a sample injector are introduced. Based on the results of 200 injectors and step back from the client to identify potential failure modes it is cleared that three sets of magnets, valve and needle are the weaknesses and vulnerable parts of an injector. To the experience of researchers in the most time, adjusting the Shim thickness of the injector is the easiest and most effective way to repair and reset of it. To achieve the optimal placement of shims in a test rig, various thicknesses of shims was placed in the injector.Penetration of the spray, spray cone, droplet size and performance of the motor in vehicle test were evaluated to achieve the optimal placement of the shims. The results show that in each case the parts to fix it, there is an optimum thickness Shim that it is certified in the both injector flow test and the actual engine test.

In this applied research, using the breakdown maintenance of the machine engine, a procedure maintenance and preventive maintenance on the fuel system, which was the main cause of the engine breakdown of these machines, was investigated. A case study was conducted on the engine of 80 Bumag BW211D rollers produced by Bumag factory, equipped with Common Rail fueling system, which were working in road construction projects in Fars, Bushehr, Hormozgan, Kohkiluyeh and Boyr Ahmad provinces. First, the data on the amount of damage and imposed costs were collected, and by designing eight service models on the fueling system, which consisted of performing and not performing three periodic services of 250, 500, and 1000 hours on the engine and the fueling system, the life of the injectors of these devices were analyzed completely randomly through the F test with an error level of 1% and the significant effect of the services on the lifetime of the injector needles was observed. Each other and on the life of the injector needles was significant. The significance of the effect of triple services in reducing fuel system costs and increasing the life of injector needles based on engine operating hours covered a low range of 700 hours in case of no service to a high range of 10, 000 hours in case of full service. By examining the working hours compared to the increase in the cost-to-income ratio of the machine in case of no service, the inverse relationship between cost and income was drawn with R 2 =1. At the end, the suggested solutions to increase the life of the injector needles such as using water separator filters and tank drainage from water and sediments were suggested.

In this experimental study, the fuel system of the OM364 diesel engine manufactured by IDEM company, which operates in the basic mode with inline fuel pump and mechanical governor control, is upgraded to a common rail system with electronic control by the ECU. Also, emmssion of exhaust gases is reduced by SCR and DOC catalysts then performance and emmission parameters of engine are compared in two cases. The base engine of OM 364 with Euro 2 emission standard is upgraded to Euro 5 EEV emission standard after changing the fuel system to common rail and after refining the exhaust gases with SCR and DOC catalysts. The important point is to pass the Euro 5 EEV standard without using DPF in exhaust gas refining, which reduces the cost of car manufacturers.

A generation method for the rail random irregularity with arbitrary wavelength interval (WI) is developed, and its accuracy and efficiency are demonstrated. Then a moving wheel-rail-bridge interaction element is derived to establish the finite element equations of motion for the train-railbridge interaction system, and the flow chart of assembly and calculation for the system equations is given. According to the sub-interval principle, the influences of the irregularities with the large WI and the sub-intervals on the dynamic responses are analyzed by a numerical example, and the sensitive WI of each response is discussed. The results indicate that the bridge acceleration and the contact force are both more sensitive to the irregularity with WI (1~5 m). The irregularity with WI (0.1~1 m) has less influence on the car body acceleration but mainly contributes to the rail acceleration. However, all the irregularities with wavelengths at interval (1~150 m) can have significant influences on the car body acceleration. Meanwhile, the transient jump of wheel can be simulated and should be taken into account for the derailment risk assessment.

In order to study the genetic control of resistance to common smut in maize, two resistant inbred lines, K1264/1 and K47/2-2-21 and two susceptible inbred lines, K3304/1-2 and K47/2-2-1-3-3-1, were crossed as K1264/1 × K3304/1-2, K47//2-2-21 × K3304/1-2 and K1264/1 × K47/2-2-1-3-3-1. The F1, F2, BC1 and BC2 progenies were produced and evaluated along with parents using randomized compelet block design with three replications. All generations were artificially inoculated with spordia of Ustilago maydis suspension. Inoculation was carried out 7-10 days after silking through injection of 3 ml of 106 spores/ml fungal suspension, using tip injection method. At maturity, disease severity was determined based on ears infection and analysed according to generation means analysis method for three crosses. Joint scaling test showed that the presence of additive, dominance and epistasis effects, especially additive × additive and dominance × dominance type, and in lesser extent, additive × dominance, in genetic control of resistance to maize common smut. Average broad and narrow-sense heritability based on three crosses data were estimated 80.3 and 57.3, respectively.

In this paper the analysis and design of an operational amplifier is presented. This amplifier can follow the input signal from ground to supply voltage at its input and output. Based on the level of the input common mode voltage, one of two pMOS and nMOS differential pairs are selected to amplify the input signal. This causes the amplifier performance is independent of the drain current relationship of the input differential pairs transistors. Both static and dynamic currents of the class AB output stage are provided by two translinear loops with minimum sensitivity to process, temperature and supply voltage variations. The simulation results, in a 0.18  CMOS technology, show that the amplifier in nominal condition, has about 80 dB dc voltage gain, 51 MHz unity gain bandwidth and 63  phase margin while its static power consumption is almost 1 mW. For input common mode voltage changes between ground to the supply voltage, the maximum relative variations of the input differential pairs transconductances, amplifier’s dc voltage gain, phase margin and unity gain bandwidth are , ,  and , respectively. This amplifier as a buffer can drive a load consisting of parallel connection of a resistor  and a capacitor 20 pF.

Pressure fluctuations during fuel injection are one of the factors that negative effect on performance of diesel engine. These fluctuations are caused by the rapid opening and closing of the nozzles and the creation of pressure waves in the fuel rail. One way to control these pressure fluctuations is to change the injector design and use an accumulator in the injector. This study is performed to investigate the effect of adding accumulator on the injector to control pressure waves in the common rail fuel injection system of diesel engines. As the simulation results show, at injection pressure of 1000 bar and energizing time of 0. 8 milliseconds, in the case of no accumulator, the maximum pressure fluctuation in the fuel rail is 1046 bar and the minimum pressure is 891 bar. By adding an accumulator with a volume of 4 cm 3, the maximum pressure continued to decrease and reached 1023 bar, and the minimum pressure of the fuel rail increased by 17 bar, 943 bar. These changes are also noticeable in other pressures and energizing times, so the best accumulator that has the most impact on reducing pressure fluctuations is the accumulator with a volume of 4 cm 3.

Diesel engines in both automotive and industrial types are one of the most efficient engines in the world. Improving emissions and reducing fuel consumption is of great importance in the automotive industry. There are various methods in order to reduce emissions and fuel consumption of diesel engines. In this paper, at first it is tried to use the common rail fuel injection system to provide high pressure fuel behind the injectors and improve combustion inside the combustion chamber. It will decrease, soot, HC and CO emissions and fuel consumption while maintaining the performance of the OM355 diesel engine. It should be noted that by using the common rail system and better evaporation of fuel by the injection system and increasing the combustion efficiency, while reducing soot, HC and CO, the amount of NOX also increases. Therefore, after this stage, using a system to reduce the amount of NOX is necessary to create a trade-off between soot, HC, CO and NOX. So, with the use of Selective catalytic reduction (SCR) catalyst, which is one of the efficient technologies for controlling and reducing NOX, the amount of NOX in the post-combustion phase is significantly reduced. The experimental results of the OM355 engine test show the proper operation of the common rail and SCR systems.