The purpose of present paper is simulation a direct INJECTION stratified CHARGE natural gas engine. The KIVA-3V code was used for gaseous fuel INJECTION simulation. Compression and expansion stroke of engine cycle is simulated using KIVA-3V code. In cylinder fuel equivalence ratio distribution criterion is used for studying mesh independency. The results show that 550000 cells number is sufficient. The amount of NO emission in the end of closed cycle simulation was found equal 674.875 ppm and In cylinder pressure versus engine crank angle degree was simulated that maximum value found in 366 oCA that equal to 27.3222 bar.

In this article, a model is used for the operation of a typical carbon nanotube actuator. Moreover, the related electromechanical coupling relations as well as the equations governing the actuation process are described. By solving such a system of equations numerically, important parameters such as the induced strain curve are investigated for different geometries. The deformation parameters for a zigzag (10, 0) CNT material are investigated. As a result, the transverse dimensional CHARGE is increasing with the electron CHARGE INJECTION level while the longitudinal dimensional CHARGE is negative that shows a shrink in the axial direction of the CNT material. The value of the torsional deformation is constant of zero for this type of structure. The longitudinal, transverse, and torsional deformations for a chiral CNT fiber (of 10,2) are presented. As shown, both of the longitudinal and transverse dimensional CHARGEs are increasing with the doping percentage level while there is an expansion in the radial direction and a shrink in the axial direction of the CNT. The expansion in the radial direction for this type of CNT is about 0.35% while for the axial direction the shrink is about 0.25% for the same level of electron charging. The torsional deformation for such a CNT material is about 0.45%. The effect of the bound length on the electro-mechanical factors is also studied. At the end, possible applications of such carbon nanotube materials for the actuator and sensing devices are discussed.    

Homogeneous CHARGE compression ignition (HCCI) is an advantageous combustion concept for internal combustion engines in terms of efficiency and pollutant emissions. However, the limited operating range of this combustion concept suppresses its successful utilization. One applicable method to use this combustion concept is to combine it with other similar combustion concepts, such as diesel and partially premixed combustion (PPC), while each concept is considered in its optimum operating range. In this study, the transition from PPC to HCCI combustion is determined based on investigating the performance and emission characteristics obtained from experimental data. The determination is based on the fact that in the direct-INJECTION (DI) HCCI combustion, the stratification generated from the fuel INJECTION is not an influencing factor. The results reveal that in the case of very early fuel INJECTION timing (when the whole INJECTION is completed before 60 crank angle degrees to top dead center), the HCCI combustion regime is obtained.

Homogeneous CHARGE compression ignition (HCCI) is an advantageous combustion concept in terms of efficiency and pollutant emissions. However, its limited operating range suppressed its successful utilization. One applicable method to use this concept is to combine it with other combustion strategies. Direct fuel INJECTION into the combustion chamber is an applicable strategy aiming at this target. To make this concept an applicable one for engines, there should be validated models both for performance prediction and control applications. Single zone models are good and rapid performance predictors and can be used in control applications. Due to the intrinsic characteristics of HCCI being a kinetically controlled combustion, chemical kinetics should be incorporated in modeling it. Therefore, in this study a stand-alone single-zone thermo-kinetic model is developed and validated against experimental measures. Since the main assumption of the developed model is the immediate vaporization of the injected liquid fuel, the validity of the model confirms the idea which states that in the case of early direct fuel INJECTION, in-cylinder combustion can be regarded as HCCI. Furthermore, the results show good agreement with the measurements. The model predicts combustion phasing within 0. 5 crank angle degrees while engine power is estimated with an acceptable accuracy of 90 percent.

Natural gas characteristics make it an attractive choice for replacing with oil fuels which causes climatic problems and environmental pollutions in the world. Generally, using natural gas in an internal combustion engine leads to lower volumetric efficiency of the engine, but gas direct INJECTION technology would improve volumetric efficiency. Furthermore, more research is essential for improving the effectiveness of direct INJECTION engines. A partially stratified CHARGE is an appropriate idea for combustion efficiency improvement in direct INJECTION engines. In the present study, a port INJECTION engine is converted to direct INJECTION engine and feasibility and condition of partially stratified mixture formation are investigated. Also, its effects on combustion and efficiency of the engine, with regards to location and INJECTION timing of injector are noticed. Numerically simulation of current study shows that the formation of partially stratified CHARGE, because of using air-guided method and located injector between air intake valves, is so hard and inaccessible. The high momentum of CNG jet makes a rapid motion of injected gas fuel and is not able to perform an appropriate mixture of air and fuel. Accordingly, an increase in air and fuel ratio is locally seen in the combustion chamber as this causes a drop in combustion efficiency. Although the increase in flame propagation and heat release can be expressed as results of this study, however, the benefits of rapid burning of CNG combustion due to the problems that are mentioned are not so impressive.

Introduction: In different studies worldwide, gender ratios derived from ICSI (Assisted reproductive techniques) have been reported differently. Objective: Evaluation of neonatal gender in ICSI women referred to Mehr Infertility Research Center of Rasht. Materials and Methods: In this descriptive-analytical study, the cases of infertile women referred to Mehr Infertility Research Center in Rasht for ICSI were examined to determine the sex ratio of the neonates. Data were analyzed using SPSS 21 and descriptive and an alytical (Chi-square and independent t) tests. Results: The results showed that 52% of single-born neonates, 60% of multiple pregnancies (single sex) and 52. 5% of multiple pregnancy (two sexes) were male. Conclusion: The ratio of male in single and multiple pregnancies in ICSI was higher than female.

In this investigation, a model has been developed to predict the performance and emissions - NOx, CO and soot-in a direct-INJECTION stratified-CHARGE engine with a Texaco controlled combustion system (TCCS). This model uses the k-epsilon turbulence model to determine characteristic velocities for heat transfer calculations, that has only an empirical constant by comparison with Woschni"s equation in which separate constants are used for each process in the four stroke cycle to determine the velocity for use in the Reynolds number. The modified Keck and Blizard model is used for combustion calculation by considering the rapid compression effects on the turbulence intensity. Extended Zel"dovich mechanism has been used to predict NOx emissions. To predict CO emissions, the Zeleknik and McBride models have been used. A certain model has been used to predict the mass of soot formed and oxidized. Comparison of the model predictions with available experimental data shows good agreement. Moreover, the program has a high flexibility for parametric studies to calculate the effect of engine parameters such as fuel-ah ratio, engine speed, INJECTION timing period and percentage of exhaust gas recirculation (EGR) on the performance and emission characteristics of the engine.

In this report, the distribution and deviation of electric field in the active medium of the TE CO2 laser has been investigated due to the INJECTION of net electron CHARGE beam as a plasma generator. Some parameters of system have been considered, such as density and mean-free-path of injected CHARGE beam. The electric potential and electric field distribution have been simulated by solving the Poison’ s equation using the method of successive over relaxation (SOR) numerical method. The electrode potential and the number of injected CHARGEd particles are respectively considered to be +75 kV and 108 mm-3. In these conditions, the maximum energy of the electrons beam would be at the order of 1-2 eV. Deviation of the electric field with different mean-free-path of electrons beam with Gaussian density distribution has been numerically calculated. It has been concluded that if the net CHARGE density is increased then the field deviation would grow. Moreover, if the mean-free-path of the electrons is decreased, subsequently, the electric field deviation is increased.

In this work, we used normal flow INJECTION analysis for determining two drugs of Quercetindehydrate symbolized as QE and Diosmin symbolized as DSN. The aim was to develop a simple, rapid, less expensive, linear, precise and accurate technique using p-Methylaminophenol Sulfate (MFS) in the presence of an oxidative agent of Sodium per iodate in aqueous medium. After the experimental conditions were passed, ideal conditions were adopted for this work, and the detection of the highest absorption of the two drugs was reached. Detected at the Maximum wavelength, we recorded them (QE= 641 nm and DSN = 665 nm). We studied beaver each drug by flow INJECTION technique chosen concentration rang from (2-160) mg .ml-1 for QE and DSN with MFS reagent in presence of oxidative agent draw calibration graph which gave a linear relationship with correlation coefficients of 0.9994 and 0.9989, respectively. The sample response time for each drug was 20 seconds for QE and 19 seconds for DSN and the detection limit for the proposed approach was (1.4×10-5) for QE and DSN, depending on trace drug concentration. The proposed approach was used to study and determine the two suggested medications in INJECTIONs and tablets with great effectiveness.

Background and Aim: The CHARGE nurse role has received little attention in the nursing literature when compared with other nursing leadership positions. Although many hospitals have CHARGE nurse position, there is a lack of clear guidelines concerning the role, competencies needed for optimum role performance, and criteria for evaluating performance. The aim of this study was to determine competencies necessary to be a successful CHARGE nurseMaterials and Method: A descriptive study was conducted by a questionnaire comprising basic data and CHARGE nurse competencies. The questionnaire was designed based on the literature and 61 competency statements were grouped into the following six categories: clinical/technical, planning, organizing, staffing, directing/leadership and controlling/supervision. Marquis and Huston's framework of the management process model were used to categorize the competency statements of management. The census sampling method was used to recruit the subjects. The questionnaire was returned by 96 subjects including 66 CHARGE nurses, 20 head nurses and 10 supervisors working in selected teaching hospitals in Arak city. Data were analyzed by SPSS 13 and descriptive statistics.Results: All competency items received mean scores of more than 4.05. The items controlling/supervision and directing/leadership were evaluated more important than staffing, planning, organizing and clinical/technical items.Conclusion: The results of this study provide guidelines for management development programs, training, and career planning for CHARGE nurses, and can also provide guidelines for recruiting and selecting effective CHARGE nurses.