Due to the limited space in transport vehicles, the CI engines with high power density has always been a priority. In heavy-duty diesel engines, direct injection results creation of the lean region in the space of the combustion chamber. Increasing the fuel penetration by changing injection duration is an effective solution to achieve homogenous mixture. In this paper, impact of changing Injection duration in upgraded MTU-4000-R43L diesel engine on power characteristics, rate of heat release (RoHR), combustion phasing, emission and, most importantly, the gradient of pressure changes as a characteristic of the vibration and knocking of the engine, has been studied numerically. Numerical simulation is performed in AVL Fire which is coupled with reduced detail chemical kinetics. the fuel Injection duration was varying from 14.6 to 35.6 oCA, the in-cylinder mean pressure, the IMEP decreases and the ISFC increases; however as the fuel Injection duration decreases, the pressure gradient rises; from the range of 30.6 degrees onwards, the reduction of the fuel Injection duration leads to a severe knock of the engine and as a result reduces its engine life. Emission results also showed that CO2 and NOx increased and CO reduced with decreasing fuel decreasing Injection duration.

Pollutant emissions from diesel engines are significantly affected by fuel injection strategies that could reduce NOx and Soot emissions. For the first time and in this study, numerical simulations were performed to consider the influences of changing the injection duration in each pulse of the double injection strategies on in-cylinder parameters and pollutant emissions. Results confirmed that double injection strategies could influence the in-cylinder temperature, which leads to a reduction in NOx and soot emissions. Additionally, it is seen that decreasing the injection duration could increase the in-cylinder peak pressure and temperature. It could also reduce the soot emission owing to the better fuel atomization. Moreover, RATE+0.5CA case, which injection duration for each pulse increases 0.5 CA, was selected to be the optimum case in reduction of pollutant emissions.

The purpose of this study is to investigate the effect of injection parameters on a heavy duty diesel engine performance and emission characteristics. In order to analyze the injection and spray characteristics of diesel fuel with employing high-pressure common-rail injection system, the injection characteristics such as injection delay, injection duration, injection rate, number of nozzle holes were investigated by using a quasi- dimensional model. In this work, different injection rate is considered with various injection parameters and performance and emission of the engine is simulated.The aim of this work is finding the best injection system for a high efficiency and low NOx emission heavy duty diesel engine.

Fuel metering system and controlling fuel-air mixture of spark ignition engines have been the major goals for the researcher. Management in mixture quality and fuel economy have resulted in changing carburetor systems to injection systems. Start of fuel injection position and injection duration play important role in engine performance. In the current work a single cylinder research engine with capability of adjusting spark timing and controlling gasoline injection start position and duration was utilized. Compression ratio, engine speed and injection start position were adjusted to 8, 1800 rpm and breathing top dead center (BTDC), respectively. Injection duration and spark timing were controlled so that to achieve maximum output torque at equivalence ratio of 0.90. Fixing them, the start of injection was only changed in the range of -180 to 180°CA relative to BTDC with a 30°CA increment. For each case, cylinder pressure of 500 successive cycles were recorded and stored. The obtained results showed that the dispersion of indicated mean effective pressure (imep) data of the cases with injection position start after BTDC were higher than those of the cases with injection position start before BTDC. Also, the average values of imep and peak pressure and their coefficient of variation changed with varying fuel injection start position; and for the cases of high dispersion in imep data, the average values of imep and isfc appeared to be high and low respectively.

Enoxaparin is widely used in acute coronary syndrome patients to prevent progression of coronary artery disease. Pain of injection site is the unpleasant result of subcutaneous Enoxaparin injection which causes the patient physical discomfort. One of the nurses’ tasks is applying techniques which cause the reduction of damage to the patient. This clinical trial study investigates the effect of injection duration of subcutaneous Enoxaparin on site-pain intensity in acute coronary syndrome patients hospitalized in Coronary Care Unit. Seventy 30-75 year-old acute coronary syndrome patients hospitalized in coronary care unit were selected randomly. Enoxaparin was injected randomly to either right or left side of abdomen with a 12-hour interval during 10 seconds and 30 seconds. In order to assess the site pain intensity, visual analog scale (VAS) was used before and immediately after injection. Data analysis was done by descriptive statistics and non-parametric tests. Results indicated that mean of pain intensity before 10 seconds is 0.78±4.93, after 10 seconds is 15.95±19.43; before 30 seconds is 0.64±3.79 and after 30 seconds is 8.08±12.91. Thus, 30 second duration of injection resulted in significant less pain intensity (P=0.000). There was no relationship between pain and sex, age and educational level. According to the study results, increasing injection duration of subcutaneous Enoxaparin to 30 seconds reduces the site pain intensity.

Increasing the power and improving the performance of diesel engines is always considered by diesel engine manufacturers. Changing the geometry of the injector outlet orifice has a major impact on fuel-air mixing and combustion. In the current study, the geometry of the injector orifice is changed from circular to annular cross-section, and the effect of different injection pressures on diesel engine performance is investigated. All numerical simulations are performed by using AVL Fire code. The results show that the annular injector improves combustion and engine performance by forming better fuel distribution. Fuel injection pressure affects the performance of the annular injector in terms of droplet distribution and breakup. At low injection pressures, due to the long injection duration, most of the fuel energy release occurs after the top dead center (TDC). Therefore, the engine performance is improved, and the combustion chamber temperature and pressure are limited. However, at high injection pressures, less combustion occurs after the TDC. By changing the injector geometry to the injector with an annular cross-section orifice, the maximum reduction in SFC value is for case P5 and injection durations 10 degrees, which is decreased by 21.4%. The maximum power increase was 15% for a 2.5% fuel increase at an injection pressure of 100MPa. While NO pollutant increased slightly by changing the type of injector at different injection pressures, the soot produced at the beginning of the combustion process was well oxidized before the end of the work phase, and its amount reached less than 2e-6.

The water alternating gas injection (WAG) method is a powerful technique that is capable of production of unrecoverable oil. The main purpose of WAG is to improve gas sweep efficiency by injecting water slugs. Reservoir rock, fluid properties, formation heterogeneity, injection method, and its subsequent parameters (e.g., WAG ratio, size of injected slug, rate of injection, injection duration) can affect the flooding recovery. The main purpose of this study is to implement a simulation-optimization algorithm to optimize water flooding, gas injection and WAG flooding. For this purpose, an Iranian offshore formation is used as a case study. Subsequent to a natural production period, different scenarios are considered. In all scenarios, the available operational parameters are considered as an optimization parameters; while, the recovery of the field is considered as an objective function. Optimization of each parameter results in finding the highest ultimate oil recovery for each scenario.

In order to detect pollutants in water distribution systems, sensors are used which, in addition to detecting pollution, also provide useful information to identify the source of pollutants. This information is useful for finding a suitable solution for quality management of the distribution network. The purpose of this study is to determine four characteristics of the pollution source to the system by a simulator-optimizer approach with optimally allocating two sensors in EPANET Example 2. These characteristics are: the contaminant injection node, injection mass rate, injection starting time and injection duration time. EPANET and genetic algorithm were linked as the simulator and optimizer tools to achieve these goals, simultaneously. For this purpose, first ten different pollution events were generated randomly, then the best place to install sensors in the network for identifying the source of pollution was found. Moreover, the shortest time of detection was selected among fourteen different combinations with a contamination source identification likelihood equal to 90%. The results showed that by placing sensors in two nodes 15 and 27 of the benchmark problem, the highest contamination source identification likelihood equal to 90% and the minimum detection time equal to 58 minutes were achieved.

Conventional compression ignition (CI) engines are known for their high thermal efficiency compared to spark ignited (SI) engines. Gasoline because of its higher ignition delay has much lower soot emission in comparison with diesel fuel. Using double injection strategy reduces the maximum heat release rate that leads to NOx emission reduction. In this paper, a numerical study of a gasoline fuelled heavy duty Caterpillar 3401 engine was conducted via three dimensional computational fluid dynamics (CFD) procedures and compared with experimental data. The model results show a good agreement with experimental data. To have a better design the effect of injection characteristics such as, the main SOI timing, injection duration and nozzle hole size investigated on combustion and emissions and an optimized point find. The results suggest an optimization in injection characteristics for simultaneous reduction of NOx and soot emissions with negligible change in IMEP.

Bruising and pain are the most common complications of heparin subcutaneous injection that can be leads to limited areas for next injections, anxiety, disturbance of body image, refusal of treatment by patient and reduce the effectiveness of nurse-patient trust. Although various methods have been proposed to minimize this unwanted effects but so far none of these methods has not been able to effectively reduce the adverse effects. The aim of this study was to compare the effects of air locks and duration of pain and bruising caused by the subcutaneous heparin injection. This Quasi-experimental study, done on 35 patients that treated with subcutaneous heparin in ICU, CCU, emergency and cardiology wards in Imam Khomeini hospital in Tehran. For each patient, two injections of 10 seconds without the use of an air lock (the usual method), and 30 seconds with the use of air lock (case study method) were carried out in the abdomen on the right or left, randomly. The interval between injections was 12 hours. Bruising 24 and 48 h after injection was measured using a plastic ruler and pain was measured using the VAS scale immediately and 24 hours after injection. Size of the bruises caused by the injections in study method, significantly less than the size of the bruises were caused by injection in the usual method (P≥0.0). Average size of the bruises in the usual method at 24 and 48 h after injection of subcutaneous heparin were 1.791 and 1.817 respectively, And 0.854 in study method. Pain intensity immediately after injection in study method was significantly less than it in usual method (P≥0.004). Difference in pain intensity in two method 24 hours after injections was not significant, although average of pain intensity in study method was less than pain in usual method. Due to the dramatic reduction in size of the bruising and pain caused by subcutaneous injection of heparin, looking to increase the injection time and the use of air lock in order to improve the quality of care and minimize unpleasant and stressful experience for patients, increasing the injection duration to 30 seconds and use an air lock heparin subcutaneous injection is recommended.